OREGON CONVENTION CENTER USDA NIFA, …caes2.caes.uga.edu/research/beefsafety/documents/JULY242015PDS...kira newman, lee-ann jaykus, juan s. leon.....47 plant microbiota-driven facilitation

USDA NIFA, Institute of Food Safety and Nutrition

Division of Food Safety

Joint Project Directors Meeting

USDA NIFA, Institute of Food Safety and Nutrition

Division of Food Safety

Joint Project Directors Meeting

OREGON CONVENTION CENTER

EXHIBIT HALL A

PORTLAND, OREGON

JULY 24, 2015

EVALUATIONS

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TABLE OF CONTENTS

AGENDA ...........................................................................................................................................6

PROGRAM OVERVIEW .....................................................................................................................7

PROGRAM ABSTRACTS .............................................................................................................. 17

(Alphabetized by Project Director Last Name).................................................................................. 17

PATHOGEN AND HOST MECHANISMS INVOLVED IN SALMONELLA INFECTION OF TOMATO ... 17

CRAIG ALTIER (Project Director)................................................................................................... 17

Nugent, S. L.; Meng, F.; Martin, G. B.; Altier, C. .............................................................................. 17

REGULATION OF SALMONELLA VIRULENCE BY THE INTESTINAL ENVIRONMENT ................... 17

CRAIG ALTIER (Project Director)................................................................................................... 17

Eade, C. R.; Hung, C.; Bullard, B.; Gonzalez-Escobedo, G.; Gunn, J. S.; Altier, C. ............................ 17

EVALUATION OF SAMPLE EFFECTS ON DETECTION OF LISTERIA MONOCYTOGENES IN

SMALL PRODUCE FARMS........................................................................................................... 18

PETER BERGHOLZ (Project Director) ........................................................................................... 18

Schmidt, K. N. Mann, M. A.; Schmidt, J. P.; Bergholz, P. W. ............................................................ 18

ELUCIDATION OF ENVIRONMENTAL FACTORS THAT INFLUENCE ATTACHMENT OF

FOODBORNE PATHOGENS TO BIOTIC AND ABIOTIC SURFACES .............................................. 19

TERESA BERGHOLZ (Project Director) ......................................................................................... 19

DIFFERENTIAL GENE EXPRESSION INDUCED BY AFLATOXIN B1 CONTAMINATED PEANUT

SLURRY IN HEPG2 CELLS .......................................................................................................... 19

SAMUEL BESONG (Project Director) ............................................................................................. 19

Prince G. Boakye, Stephen E. Lumor, Samuel A. Besong (Project Director)...................................... 19

ENGINEERED NANOMATERIALS IN FRESH CROPS: A FOOD SAFETY ISSUE? .......................... 20

ACHINTYA BEZBARUAH (Project Director..................................................................................... 20

Bezbaruah, A.N.; Katti, D.; Otte, M.; Katti, K.; Jacob, D.; Gonzalez, J. .............................................. 20

TRAINING OF MINORITY STUDENTS IN NUTRIGENOMICS ......................................................... 20

JUDITH BOATENG (Project Director)............................................................................................. 20

Boateng, J.; Verghese, M. ............................................................................................................. 20

EFFECTS OF ORGANIC ACID-SURFACTANT MIXTURES ON LEVELS OF BACTERIA

AND BEEF QUALITY TRAITS ....................................................................................................... 21

MICK BOSILEVAC (Project Director).............................................................................................. 21

Mick Bosilevac, Nor Kalchayanand and Andy King .......................................................................... 21

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IDENTIFICATION OF RISKY FOOD SAFETY PRACTICES AND MICROBIAL ASSESSMENT OF

PRODUCE AT SOUTHWEST VIRGINIA FARMER’S MARKETS ..................................................... 22

RENEE BOYER (Project Director).................................................................................................. 22

Boyer, R.; Pollard, S.; di Stefano, J.; Chapman, B.; Ponder, M.; Archibald, T. ................................... 22

AN INTEGRATED PLATFORM FOR DETECTION OF BRUCELLOSIS FROM DAIRY PRODUCT .... 22

HSUEH-CHIA CHANG (Project Director) ........................................................................................ 22

Shah, S. Senapati, Z. Slouka, Y. Men, F. Klacsmann, F. Mejia and H -C. Chang................................ 22

MICROBIOLOGICAL EVALUATION OF POULTRY PRODUCT PACKAGES FROM GROCERY

STORES IN NASHVILLE, TENNESSEE......................................................................................... 23

FUR-CHI CHEN (Project Director).................................................................................................. 23

Chen, F.; Godwin, S.; Green, A.; Chowdhury, S.; Stone, R. ............................................................. 23

ATMOSPHERIC COLD PLASMA INACTIVATION OF NOROVIRUS SURROGATES AND NATIVE

MICROBIOTA ON BLUEBERRIES................................................................................................. 24

HAIQIANG CHEN (Project Director) ............................................................................................... 24

Niemira, B. A.; Lacome, A.; Gurtler, J.; Sites, J.; Boyd, G.; Li, X.; Chen, H.; Fan, X.; Kingsley, D. ....... 24

VARIABLE HIGH PRESSURE PROCESSING SENSITIVITIES FOR GII HUMAN NOROVIRUSES ... 24


Lou, F.; Li, X.; Dai, X.; Ma, Y.; DiCaprio, E.; Hughes, J.; Chen, H.; Kingsley, D.; Li, J......................... 24

EFFICACY OF LOW-TEMPERATURE HIGH HYDROSTATIC PRESSURE PROCESSING IN

INACTIVATING VIBRIO PARAHAEMOLYTICUS IN OYSTER HOMOGENATE ................................. 25


Phuvasate, S.; Su, Y. .................................................................................................................... 25

ATTACHMENT ABILITY OF SHIGA TOXIN-PRODUCING ESCHERICHIA COLI TO ALFALFA,

LETTUCE, TOMATO AND FENUGREEK SEEDS ........................................................................... 26

JINRU CHEN (Project Director)...................................................................................................... 26

Yue Cui, Ronald Walcott, Jinru Chen.............................................................................................. 26

ATTACHMENT OF VARIOUS SEROVARS OF SALMONELLA ENTERICA TO VEGETABLE SEEDS

WITH DIFFERENT SURFACE CHARACTERISTICS ...................................................................... 27

JINRU CHEN (Project Director)...................................................................................................... 27

Yue Cui, Ronald Walcott, Jinru Chen.............................................................................................. 27

MICROFLUIDICS AND PHYSICS-BASED APPROACHES TO ELUCIDATE PHYSICAL

MECHANISMS OF FRESH PRODUCE CONTAMINATION ............................................................. 27

ASHIM DATTA (Project Director) ................................................................................................... 27

Warning, A.; Datta, A..................................................................................................................... 27

INFLUENCE OF HEAT TRANSFER WITH DIFFERENT CONTAINER SIZE ON MEASURED

THERMAL INACTIVATION PARAMETERS OF HEPATITIS A VIRUS .............................................. 28

MICHAEL DAVIDSON (Project Director)......................................................................................... 28

Bozkurt, H.; D’Souza, D. H.; Davidson, P. M. .................................................................................. 28

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INTERNALIZATION OF SALMONELLA IN ARACHIS HYPOGAEA, PEANUT PLANTS AND SEED

POD............................................................................................................................................. 29

FRANCISCO DIEZ-GONZALEZ (Project Director) .......................................................................... 29

Rossbach, J. D.; Freund, B.; Nitti, M.; Schneider, O.; Fink, R. C.; Sadowsky, M. J.; Tong, C.; Diez -

Gonzalez, F. ................................................................................................................................. 29

THERMAL RESISTANCE OF SALMONELLA IN DRY EXTRUDED CEREALS: KINETIC

PARAMETERS AND THE ROLE OF IRON CONTENT ................................................................... 30

FRANCISCO DIEZ-GONZALEZ (Project Director) .......................................................................... 30

Maserati, A.; Fink, R. C.; Lourenco, A.; Diez-Gonzalez, F. ............................................................... 30

ACCUMULATION OF ENGINEERED NANOPARTICLES IN PLANT FOODS: NUTRITIONAL

BIOACCESSIBILITY AND DIETARY EXPOSURE RISKS................................................................ 30

STEPHEN EBBS (Project Director) ................................................................................................ 30

Ebbs, S. D.; Bradfield, S.; Ma, X. ................................................................................................... 30

MODELS FOR THE SURVIVAL OF SALMONELLA IN LOW-WATER ACTIVITY, HIGH FAT FOOD

SYSTEMS AT 80C........................................................................................................................ 31

JOSEPH FRANK (Project Director) ................................................................................................ 31

Trimble, L.; Barnes, S.; Frank, J. .................................................................................................... 31

NON-EQUILIBRIUM PLASMA-ACTIVATED WATER IN AGRICULTURE: PATHOGEN CONTROL,

PLANT GROWTH ENHANCEMENT, AND REDUCTION OF IRRIGATION WATER CONSUMPTION 32

ALEXANDER FRIDMAN (Project Director) ..................................................................................... 32

Fridman, G.; Miller, V.; Rabinovich, A.; Fridman, A .......................................................................... 32

ENHANCING FARMERS MARKET FOOD SAFETY PRACTICES FOR FRESH PRODUCE

HANDLING................................................................................................................................... 32

KRISTIN GIBSON (Project Director)............................................................................................... 32

Gibson, K.; Wright, K.; Sirsat, S.; Neal, J. ....................................................................................... 32

UNDERSTANDING SALMONELLA-TOMATO PLANT HOST INTERACTIONS AND DEVELOPMENT

OF NOVEL EFFECTIVE CONTROL STRATEGIES TO REDUCE SALMONELLA BURDEN IN

TOMATO...................................................................................................................................... 33

RAJASHEKARA GIRESH (Project Director).................................................................................... 33

Deblais I, L.; Gurel, F.; Miller, S.; Rajashekara, G. ........................................................................... 33

ASSESSMENT OF TEMPERATURE AT RECOMMENDED METHODS OF DETERMINING

DONENESS IN EGG RECIPES ..................................................................................................... 34

SANDRIA GODWIN (Project Director) ............................................................................................ 34

Godwin, S.; Stone, R.; Troupe-Austin, L.; Maughan, C.; Chambers, E. ............................................. 34

CONSUMER AWARENESS OF AND RESPONSE TO SAFETY ISSUES UPON DELIVERY

OF MEAT, FISH AND/OR SEAFOOD PURCHASED ONLINE ......................................................... 34

SANDRIA GODWIN (Project Director) ............................................................................................ 34

Godwin, S.; Stone, R.; Senger-Mersich, A.; Hallman, W. ................................................................. 34

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SERS DETECTION AND CHARACTERIZATION OF GOLD NANOPARTICLES ON AND

IN SPINACH LEAVES ................................................................................................................... 35

LILI HE (Project Director)............................................................................................................... 35

Zhiyun Zhang and Lili He ............................................................................................................... 35

DEVELOPMENT AND TRANSFER OF DISINFECTION BY-PRODUCTS INTO FRESH AND FRESH-

CUT PRODUCE AND IMPACT ON DISINFECTION EFFICACY ...................................................... 36

CHING-HUA HUANG (Project Director) .......................................................................................... 36

Wan-Ning Lee; Xi Chen, Yen-Con Hung; Ching-Hua Huang ............................................................ 36

NOVEL ELECTROLYZED OXIDIZING WATER BASED CLEANING-IN-PLACE MEAT GRINDER

SANITIZATION PROCESS DEVELOPMENT AND OPTIMIZATION ................................................. 37

YEN-CON HUNG (Project Director)................................................................................................ 37

Ravi Jadejal and Yen-Con Hung .................................................................................................... 37

INVESTIGATION OF FOOD-BORNE VIRUSES DISINFECTION BY UV-A ACTIVATED

TI02-COATED SURFACES ........................................................................................................... 37


Lingling Liu, Kranti Yemmireddy, Yen-con Hung, Jennifer L Cannon................................................. 37

ANTIMICROBIAL INTERVENTIONS FOR BLADE TENDERIZED WHOLE MUSCLE NON-INTACT

BEEF STRIP LOINS: EVALUATION OF SHELF-LIFE AND SENSORY CHARACTERISTICS ........... 38


R.J. Kersey, A.M. Stelzleni ............................................................................................................ 38

EFFECTS OF ANTIMICROBIALS ON SHELF-LIFE CHARACTERISTICS OF GROUND BEEF ......... 39


S.E. Belanger, A.M. Stelzleni ......................................................................................................... 39

GASEOUS ANTIMICROBIALS FOR PRODUCE AND LOW-MOISTURE FOOD: EQUIPMENT

DEVELOPMENT, SENSORY EVALUATION, MODELING, AND REGULATORY COMPLIANCE ....... 39

CHEN-AN HWANG (Project Director) ............................................................................................. 39

Hwang, C.; Huang, L., Fan, X. ....................................................................................................... 39

UNDERSTANDING ANTIBIOTIC RESISTANCE OCCURRENCE AND DEVELOPMENT OF

MITIGATION STRATEGIES IN CATTLE ........................................................................................ 40

K. CASEY JEONG (Project Director) .............................................................................................. 40

R. Mir and K. Casey Jeong ............................................................................................................ 40

MODELING DRY CROSS-CONTAMINATION OF SALMONELLA DURING

ALMOND PROCESSING .............................................................................................................. 41

SANGHYUP JEONG (Project Director)........................................................................................... 41

EFFECT OF SURFACE PROPERTIES ON COLLOID AND BACTERIAL RETENTION

ON NATURAL AND SURROGATE PRODUCE SURFACES ............................................................ 41

YAN JIN (Project Director) ............................................................................................................. 41

Taozhu Sun, Volha Lazouskaya, Gang Wang, and Yan Jin .............................................................. 41

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SURFACE ROUGHNESS OF FRESH PRODUCE INVESTIGATED WITH CONFOCAL

MICROSCOPY AND WHITE LIGHT INTERFEROMETERY ............................................................. 42

YAN JIN (Project Director) ............................................................................................................. 42

Volha Lazouskaya, Taozhu Sun, Gang Wang, and Yan Jin .............................................................. 42

FACTORS THAT INFLUENCE SALMONELLA COLONIZATION OF PLANTS .................................. 43

JEFFREY JONES (Project Director) ............................................................................................... 43

Potnis, Cowles, Jones and Barak ................................................................................................... 43

NANOSCALE PATTERNINGS ON STAINLESS STEEL SURFACES FOR PREVENTION OF

BACTERIAL ADHESION................................................................................................................ 43

SOOJIN JUN (Project Director)....................................................................................................... 43

Natthakan Rungraeng, Yong Li, Chang-Hwan Choi, and Soojin Jun .................................................. 43

PHYSIOCHEMICAL CHARACTERIZATION OF MICROWAVE-ASSISTED SYNTHESIS OF

SILVER NANOPARTICLES SYNTHESIZE USING ALOE VERA (Aloe Barbadensis) ......................... 44

LAMIN KASSAMA (Project Director)............................................................................................... 44

Lamin S. Kassama, John A. Kuponiyi, Tatiana Kukhtareva ............................................................... 44

AN ASSESSMENT OF FOOD SAFETY PRACTICES AT FARMERS MARKETS IN KENTUCKY ...... 45

JOHN KHOURYIEH (Project Director) ............................................................................................ 45

DIELECTRIC PROPERTIES OF BROCCOLI POWEDER AND ITS TEMPERATURE PROFILE

DURING RADIO FREQUENCY HEATING ...................................................................................... 45

FANBIN KONG (Project Director) ................................................................................................... 45

GOALS AND IMPACTS OF THE A4161 PROGRAM: PREVENTION AND CONTROL OF POULTRY

FLOCKS AND POULTRY PRODUCTS, INCLUDING EGGS ........................................................... 46

BIBIANA LAW (Project Director) .................................................................................................... 46

Bibiana Law; Qijing Zhang, Sandria Godwin, Hosni Hassan ............................................................. 46

NOROVIRUS TRANSMISSION DURING PRODUCE HARVEST AND PACKING: A QUANTITATIVE

MICROBIAL RISK ASSESSMENT MODEL APPROACH................................................................. 47

JUAN LEON (Project Director) ....................................................................................................... 47

Kira Newman, Lee-Ann Jaykus, Juan S. Leon................................................................................. 47

PLANT MICROBIOTA-DRIVEN FACILITATION OF THE PERSISTENCE, GROWTH, AND

INTERNALIZATION OF HUMAN PATHOGENS ON LEAFY GREENS ............................................. 48

JOHN LEVEAU (Project Director)................................................................................................... 48

Lorena Rangel, Gitta L. Coaker, Trevor V. Suslow, and Johan H.J. Leveau ...................................... 48

RAPID CONCENTRATION/DETECTION OF FOODBORNE PATHOGENS FROM WASH WATER

FOR ENHANCED SAFETY OF FRESH FRUITS AND VEGETABLES.............................................. 48

DANIEL LIM (Project Director) ....................................................................................................... 48

Elliot T. Ryser, Sonia M. Castillo, Elizabeth A. Kearns, and Daniel V. Lim ......................................... 48

ENHANCING LOW-MOISTURE FOOD SAFETY BY IMPROVING DEVELOPMENT AND

IMPLEMENTATION OF PASTEURIZATION TECHNOLOGIES ....................................................... 49

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BRADLEY MARKS (Project Director) ............................................................................................. 49

B. Marks, J. Tang, H. Thippareddi, E. Grasso, D. Gray, M. Zhu, J. Subbiah, E. Ryser,

S. Jeong, N. Anders ...................................................................................................................... 49

EVALUATING THE EFFECTIVENESS OF FOOD SAFETY TRAININGS BY DETERMINING

FACTORS THAT INFLUENCE GROWER ADOPTION OF F OOD SAFETY CERTIFICATION ........... 50

SHIRLEY MICALLEF (Project Director) .......................................................................................... 50

D. Pahl, T. Chfadi, C. Narrod, C. Walsh, D. Martin, S. Micallef ......................................................... 50

DYNAMICS OF THE MICROBIOME AND RESISTOME IN BEEF PRODUCTION SYSTEMS ............ 51

PAUL MORLEY (Project Director) .................................................................................................. 51

Noyes NR, Xiang Y, Linke LM, Magnuson RJ, Yang H, Dettenwanger A, Abdo Z, Jones K,

Boucher C, Belk KE, Morley PS ..................................................................................................... 51

SHIGA-TOXIGENIC ESCHERICHIA COLI (STEC) IN THE BEEF CHAIN: ASSESSING AND

MITIGATING THE RISK BY TRANSLATIONAL SCIENCE, EDUCATION AND OUTREACH.............. 51

RODNEY MOXLEY (Project Director)............................................................................................. 51

OXIDATIVE STRESS RESPONSE OF BACTERIA TO SANITIZERS ............................................... 52

NITIN NITIN (Project Director) ....................................................................................................... 52

Phuong Le, Andrea Cossu, Glenn Young, Anupama Ranganathan, Nitin Nitin .................................. 52

NANOPHOTONIC DETECTION OF PATHOGENS IN FOOD .......................................................... 52

NITIN NITIN (Project Director) ....................................................................................................... 52

S. Lakshmanan, A. Ranganathan, N. Nitin, I.M. Kennedy ................................................................ 52

BACTERIOPHAGE-BASED NANOPROBES FOR RAPID BACTERIA SEPARATION ....................... 53

SAM NUGEN (Project Director)...................................................................................................... 53

Juhong Chen, Bradley Duncan, Li-Sheng Wang, Vincent M. Rotello and Sam R. Nugen ................... 53

EXAMINING THE DYNAMICS OF NANOPARTICLES IN PLA NTS .................................................. 53

SANJAI PARIKH (Project Director)................................................................................................. 53

Devin Rippner, Ryan Davis, Matt Dumlao, Julie Sutcliffe, Andrew McElrone,

Peter Green, Wendy Silk ............................................................................................................... 53

APPLICATION OF LOW WAVE-LENGTH UV-C IRRADIATION FOR TREATING MYCOTOXINS IN

TURBID FLUIDS........................................................................................................................... 54

ANKIT PATRAS (Project Director).................................................................................................. 54

Ankit Patras, Sharath Chandra, Bharat Pokharel ............................................................................. 54

QUANTITATIVE RISK ASSESSMENT OF TAXOPLASMA GONDII INFECTION THROUGH

CONSUMPTION OF FRESH PORK IN THE UNITED STATES ........................................................ 55

ABANI PRADHAN (Project Director)............................................................................................... 55

Miao Guo, Robert L. Buchanan, Jitender P. Dubey, Dolores E. Hill, H. Ray Gamble, Jeffrey L. Jones,

and Abani K. ................................................................................................................................. 55

IDENTIFICATION AND MANAGEMENT OF CRITICAL CONTROL POINTS FOR LIMITING THE

SPREAD OF ANTIBIOTIC RESISTANCE FROM AMNURE TO FRESH PRODUCE ......................... 56

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AMY PRUDEN (Project Director).................................................................................................... 56

Amy Pruden, Katharine Knowlton, Partha Ray, Monica Ponder, Giselle Guron, Kang Xia, Cully

Hession, Leigh-Anne Krometis, Thomas Archibald, Amber Vallotton. ................................................ 56

INFECTION OF PIGS WITH SALMONELLA AND LAWSONIA INCREASES PUBLIC HEALTH RISK 57

ISAACSON RICHARDSON (Project Director) ................................................................................. 57

Isaacson, R, Singer, R., Gebhart, C. .............................................................................................. 57

ECONOMIC IMPACTS OF E. COLI MITIGATION ........................................................................... 57

PARR ROSSON (Project Director) ................................................................................................. 57

Parr Rosson and Flynn Adcock ...................................................................................................... 57

RISK ASSESSMENT AND INTERVENTION STRATEGIES FOR THE EMERGING STRATEGIES FOR

THE EMERGING FOOD SAFETY THREAT OF OCHRATOXIN IN THE UNITED ............................. 58

DOJIN RYU (Project Director) ........................................................................................................ 58

Andreia Bianchini, Jack C. Cappozzo, Lauren S. Jackson, Jeffrey D. Palumbo, Jayne E. Strat ........... 58

FOOD SAFETY EDUCATION AND BEHAVIORAL CHANGES AMONG DEAF AND HARD OF

HEARING POPULATION: A MODEL STUDY ................................................................................. 59

DOJIN RYU (Project Director) ........................................................................................................ 59

Jessie Hunter, Karen Killinger, Renee Magnan, David Mercaldo, Gulhan Unlu, and Dojin Ryu ........... 59

ALTERNATIVES TO ANTIBIOTICS IN ANIMAL AGRICULTURE: IMPACTS ON ANTIMICROBIAL

RESISTANCE OF ENTERIC BACTERIA ........................................................................................ 60

HARVEY MORGAN SCOTT (Project Director) ................................................................................ 60

Scott, HM; Boerlin, P; Drouillard, JS; Nagaraja, TG; Tokach, MD ..................................................... 60

ANALYSIS OF THE GEOSPATIAL DISTRIBUTION OF STAPHYLOCOCCUS AUREUS IN

COMMUNITIES AND RAW MEAT PRODUCTS .............................................................................. 60

TARA C SMITH (Project Director) .................................................................................................. 60

Tara C Smith, Dipendra Thapaliya, and Margaret Carrel .................................................................. 60

CONTROL OF FOOD-BORNE BACTERIAL AND VIRAL PATHOGENS USING MICROWAVE

TECHNOLOGIES ......................................................................................................................... 61

JUMING TANG (Project Director) ................................................................................................... 61

Juming Tang and Shyam Sablani ................................................................................................... 61

INTEGRATING IMMUNO-SEPARATION WITH FIBER OPTIC SPECTROSCOPIC TECHNIQUES FOR

QUICK DETECTING FOOD-BORNE PATHOGENS........................................................................ 62

SHIQUAN TAO (Project Director) ................................................................................................... 62

Shiquan Tao (PhD), Jason C. Ray, Muhammad S. Almas, Cole A Guyer, Maya Alex and Hemant K.

Naikare (PhD)............................................................................................................................... 62

ROLE OF SURFACE TOPOGRAPHY AND PHYSICO-CHEMISTRY ON DEVELOPMENT AND

APPLICATION OF NOVEL INTERVENTIONS TO INHIBIT PAHTOGEN ATTACHMENT .................. 62

MATHEW TAYLOR (Project Director)............................................................................................. 62

Oh, J. K., K. Perez-Lewis, Y. Yegin, M. Zhang, L. Cisneros-Zevallos, M. Akbulut, A. Castillo ............. 62

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FUNCTIONAL GENOMICS OF SALMONELLA-TOMATO INTERACTIONS AND CROP-DRIVEN

PATHOGEN LIMITATION: THE ROLE OF AGRICULTURAL PRACTICES IN OUTCOMES .............. 63

MAX TEPLITSKI (Project Director) ................................................................................................. 63

Teplitski, M., Marvasi, M., McClelland, M., Giovannoni, J. ................................................................ 63

HUMAN NOROVIRUS BINDING TO LETTUCE CELL WALL COMPONENTS AND ITS

INTERNALIZATION THROUGH THE VASCULAR SYSTEM ........................................................... 64

QIUHONG WANG (Project Director)............................................................................................... 64

Malak Esseili, Xiang Gao, Sarah Tegtmeier and Qiuhong Wang ...................................................... 64

NANOMATERIAL CONTAMINATION OF AGRICULTURAL CROP SPECIES .................................. 64

JASON WHITE (Project Director) ................................................................................................... 64

Jason C. White, Baoshan Xing, Lee A. Newman, Xingmao Ma ........................................................ 64

MITIGATING RISKS OF FOODBORNE ILLNESS ASSOCIATED WITH HANDLING LEAFY GREENS

IN RETAIL FOODSERVICE ESTABLISHMENTS SERVING AGING POPULATIONS ........................ 65

SUSAN WHOLSDORF-ARENDT (Project Director) ......................................................................... 65

Susan W. Arendt, Catherine H. Strohbehn, Lakshman Rajagopal, Angela M. Shaw .......................... 65

BUILDING A MULTIDISCIPLINARY FOOD SAFETY TRAINING PIPELINE FROM K-12 TO

GRADUATE SCHOOL .................................................................................................................. 66

MARTIN WIEDMAN (Project Director) ............................................................................................ 66

M. Wiedmann, S. Warchocki, K.J. Boor, A. Orta-Ramirez, K.K. Nightingale, H.F. Oliver, L.A. Jaykus, L.

Johnston, M. Verghese, S. A. Ibrahim ............................................................................................ 66

ATTACHMENT OF E.COLI 0157:H7 ON PRODUCE AND DAMAGE OF BACTERIAL CELL

ENVELOPE BY DRY PULSED LIGHT (PL), WET PL,

AND PL-SURFACTANT COMBINATIONS ...................................................................................... 67

CHANGQING WU (Project Director)............................................................................................... 67

Wenqing Xu and Changqing Wu .................................................................................................... 67

ENHANCING THE SAFETY AND QUALITY OF FRESH PRODUCE AND LOW-MOISTURE FOODS

BY WATERLESS NON-THERMAL TECHNOLOGIES ..................................................................... 68

VIVIAN WU (Project Director) ........................................................................................................ 68

Vivian C.H. Wu, David Bridges, and Irwin Quintela .......................................................................... 68

PULSED LIGHT INACTIVATION OF FOODBORNE PATHOGENS.................................................. 68


Haiqiang Chen and Kali Kniel ........................................................................................................ 68

EDUCATION OF CONSUMERS ON FOOD PROCESSING TECHNOLOGIES USING COOPERATIVE

EXTENSION AS THE DELIVERY SYSTEM .................................................................................... 69


Renee R. Boyer, Robert C. Williams and Joell Eifert ........................................................................ 69

GASEOUS ANTIMICROBIALS FOR PRODUCE AND LOW-MOISTURE FOOD: EQUIPMENT

DEVELOPMENT, SENSORY EVALUATION, MODELING, AND REGULATORY .............................. 70

11


Cheng-An Hwang, Lihan Huang, Xuetong Fan ................................................................................ 70

CHARACTERIZATION OF HUMAN NOROVIRUS CLINICAL ISOLATES AND THEIR

PATHOGENESIS IN A GNOTOBIOTIC PIG MODEL ...................................................................... 71


Yuanmei Ma, Erin DiCaprio, Xueya Liang, John Hughes, Steven Krakowka, Jianrong Li .................... 71

ENHANCING THE SAFETY AND QUALITY OF FRESH PRODUCE AND LOW-MOISTURE FOODS

BY WATERLESS NON=THERMAL TECHNOLOGIES: COLD PLASMA AND MONOCHROMATIC

LIGHT .......................................................................................................................................... 72


Brendan A. Niemira*, Alison Lacombe, Joshua Gurtler, David Kingsley, and Joseph Sites ................. 72

INVESTIGATION OF POLYMER-FUNCTIONALIZED CARBON NANOTUBE-COATED FILTERS FOR

REMOVAL OF BACTERIAL PATHOGENS ..................................................................................... 73

LIJU YANG (Project Director)......................................................................................................... 73

Shengyuan Wang, Gregory E. LeCroy, Fan Yang, Xiuli Dong,Ya-Ping Sun, Liju Yang ....................... 73

STORAGE AND SENSORY EVALUATION OF SELECTED MAPS PRODUCTS .............................. 74

TOM YANG (Project Director) ........................................................................................................ 74

Tom Yang .................................................................................................................................... 74

AROMATIC CARBON-DEGRADING MICROORGANISM-MEDIATED UPTAKE OF CARBON

NANOTUBES BY TOMATO PLANTS ............................................................................................. 74

YU YANG (Project Director)........................................................................................................... 74

Yu Yang ....................................................................................................................................... 74

PROTECTIVE SURFACE COATING TO REDUCE BACTERIAL LOAD OF FRESH AND FRESH-CUT

PRODUCE: CATALOUPE AS A MODEL ........................................................................................ 75

YUAN YAO (Project Director)......................................................................................................... 75

Yuan Yao, Arun Bhunia, Preetam Sarkar, Yezhi Fu, Amanda Deering .............................................. 75

A LONGITUDINAL STUDY ON CAMPYLOBACTER PREVALENCE IN CONVENTIONALLY-RAISED

COMMERCIAL BROILER FLOCKS IN THE UNITED STATES ........................................................ 76

QIJING ZHANG (Project Director) .................................................................................................. 76

Orhan Sahin, Nada Pavlovic, Annette O'Connor, Catherine Logue, and Qijing Zhang ........................ 76

PREVALENCE OF A HIGHLY VIRULENT CAMPYLOBACTER JEJUNI CLONE ASSOCIATED WITH

SHEEP ABORTION IN FEEDLOT CATTLE IN THE UNITED STATES ............................................. 77

QIJING ZHANG (Project Director) .................................................................................................. 77

Yizhi Tang, Orhan Sahin, Nada Pavlovic, Jeff Lejeune, James Carlson, and Qijing Zhang ................. 77

MOLECULAR MECHANISMS UNDERLYING SALMONELLA ATTACHMENT TO

FRUITS AND NUTS ...................................................................................................................... 77

WEI ZHANG (Project Director) ....................................................................................................... 77

Ye Li, Joelle Salazar, Mary Lou Tortorello, Michael McClelland, Wei Zhang ...................................... 77

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REDUCTION OF SHIGA TOXIN-PRODUCING E.COLI AND SALMONELLA TYPHIMURIUM ON

CATTLE HIDES BY SPRAY TREATMENT WITH LEVULINIC ACID PLUS SODIUM DODECYL ........ 78

TONG ZHAO (Project Director) ...................................................................................................... 78

Tong Zhao, Luxin Wang, Ping Zhao, Dong Chen, and Michael P. Doyle ........................................... 78

A VISIBLE LIGHT PHOTOCATALYST BI2CuO4 FOR BACTERICIDAL APPLICATIONS .................. 79

YIPING ZHAO (Project Director) .................................................................................................... 79

Lu Zhu, Les P Jones, Steven Larson, Ralph A. Tripp, and Yiping Zhao ............................................. 79

PROJECT DIRECTOR MEETING ATTENDEES ........................................................................... 80

CONFERENCE MENU................................................................................................................... 84

Portland Steel Bridge Continental Breakfast ..................................................................................... 84

Portland Pearl District Lunch ........................................................................................................... 84

ACKNOWLEDGING USDA-NIFA ................................................................................................... 85

USDA NIFA FOOD SAFETY DIVISION .......................................................................................... 86

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USDA NIFA Food Safety Project Directors Meeting

Portland, Oregon, July 24, 2015 * 7:00 AM-5:30 PM

AGENDA

7:00 – 8:00 Breakfast/ Registration/Poster Set-Up – EXHIBIT HALL A

8:00 – 12:30

PLENARY SESSION-ORAL PRESENTATIONS - MAIN MEETING ROOMS: B113-B115

Welcome and Moderator – Dr. Jan Singleton, Director, Food Safety Programs, IFSN

8:00 – 8:20

8:20 – 8:40

8:40 – 9:00

9:00 – 9:20

9:20 – 9:40

9:40 – 10:00

10:00 – 10:15

10:15 – 10:30

10:30 – 10:45

Keynote Speaker-Dr. C. Patrick Dunne 2014 Institute of Food Technologists (IFT) Nicholas Appert Award Winner-Establishing value of new food processing technologies through

multidisciplinary team efforts. FOOD PROCESSING TECHNOLOGIES TO DESTROY FOOD-BORNE PATHOGENS PROGRAMS

(CAP FUNDED PROJECTS)

Control of Food-borne Bacterial and Viral Pathogens Using Microwave Technologies - Dr. Juming Tang, Washington State University

Advanced Processing Technologies as Multiple Hurdles to Inactivate STEC and Viruses During Beef Processing and on Non-intact Beef Products - Dr. Yen-con Hung, University of Georgia

VIRUS and STEC FOOD SAFETY PROGRAMS

STEC CAP update - Shiga-toxigenic Escherichia Coli (STEC) in the Beef Chain: Assessing & Mitigating the Risk by Translational Science, Education & Outreach - Dr. Rodney Moxley, University of Nebraska-Lincoln

Virus CAP update - Building Capacity to Control Viral Foodborne Disease: A Translational,

Multidisciplinary Approach- Dr. Lee-Ann Jaykus, North Carolina State University

STEC Ecology update – STEC Microbial Ecology Projects – Dr. Thomas Besser, Washington

State University

BREAK

1890 CAPACITY BUILDING GRANTS PROGRAM

Enhancing Food Safety Knowledge Of Small To Medium-Sized Produce Growers In Tennessee And Illinois - Dr. Kilonzo-Nthenge, Tennessee State University

IMPROVING FOOD SAFETY and EMERGING ISSUES IN FOOD SAFETY PROGRAMS

Functional Genomics of Salmonella-tomato Interactions and Crop-driven Pathogen Limitation: the Role of Agricultural Practices in Outcomes - Dr. Max Teplitski, University of Florida

14

10:45 – 11:00

11:00 – 11:15

11:15 – 11:30

11:30 – 11:45

11:45 – 12:00

12:00 – 12:15

12:15 – 12:30

Goals and Impacts of A4161 Program: Prevention and Control of Poultry Flocks and Poultry Products, Including Eggs-Dr. Sandria Godwin, Tennessee State University and Dr. Bibiana Law,

University of Arizona

Risk Assessment and Intervention Strategies for the Emerging Food Safety Threat of Ochratoxin in the United States - Dr. Dojin Ryu, University of Idaho

Prediction and Mitigation of Foodborne Disease Potential of Emerging Trichothecene Mycotoxins - Dr. James Pestka, Michigan State University

The Role of Pigs in the Foodborne Zoonotic Transmission of Shiga Toxin-Producing Escherichia Coli - Dr. Julie Funk, Michigan State University

IMPROVING THE SAFETY OF FRESH AND FRESH CUT PRODUCE PROGRAM

Protective Surface Coating to Reduce Bacterial Load of Fresh and Fresh Cut Produce: Cantaloupe as a Model. Dr. Yuan Yao, Purdue University

EFFECTIVE MITIGATION STRATEGIES IN ANTIMICROBIAL RESISTANCE PROGRAMS

Alternatives to Antibiotics in Animal Agriculture: Impacts on Antimicrobial Resistance of Enteric Bacteria – Dr. Harvey Morgan Scott, Texas A & M University

Effective Interventions to Prevent Emergence and Dissemination of Antimicrobial Resistance at the Population, Animal & Microbial Levels – Dr. Thomas Wittum, The Ohio State University

12:30 – 3:15 LUNCH / NETWORKING / POSTERS -EXHIBIT HALL A

Poster Breakdown at 3:00 PM

3:30 – 5:30 BREAKOUT SESSIONS-MEETING ROOMS B116, B117, B118

CONCURRENT SESSION 1

Improving Food Safety

Programs

(Meeting Room #117)

HOSTED BY

Dr. Jeanette Thurston, NIFA National Program Leader;

Dr. John Reich, NIFA Program Specialist

CONCURRENT SESSION 2 Improving the Safety of Fresh & Fresh

Cut Produce Programs;

Effective Mitigation Strategies in

Antimicrobial Resistance Programs and

Emerging Issues in Food Safety Programs

(Meeting Room #116)

HOSTED BY

Dr. Mervalin Morant, NIFA National Program Leader;

Dr. Isabel Walls, NIFA National

Program Leader;

Dr. Jodi Williams, NIFA National Program Leader;

Dr. Dawanna James-Holly NIFA

Program Specialist

CONCURRENT SESSION 3

Food Processing Technologies to

Destroy Food-Borne Pathogens

Programs

(Meeting Room # B118)

HOSTED BY

Dr. Hongda Chen, NIFA National Program Leader;

Dr. Manu Manohar, NIFA Program Specialist

5:30 MEETING ADJOURNED

15

16

The USDA NIFA Food Safety Project Directors meeting will foster collaborations among researchers,

educators, and extension professionals working in food safety and related areas. The granted projects

have included a variety of local, national, international collaborations, and many unique examples of

integration. Project Directors and other university stakeholders will benefit from learning about

methodologies that have been adopted by successful grantees.

This year’s joint Food Safety program meeting will bring together research from several NIFA research

priority issue areas. These include the Agricultural Food Research Initiative (AFRI) Foundational and/or

Challenge Area programs which will be presented in Breakout Sessions 1, 2, and 3. The AFRI Food

Safety, Nutrition and Health priority area of the foundational program is single function research focused

on projects that address the microbial, physical, and chemical safety of foods, and provide information on

the function and efficacy of foods, nutrients, and other bioactive components in promoting health. In

addition, knowledge generated will improve processing, packaging and storage technologies to enhance

the safety, quality and shelf life of foods. This knowledge will improve our unders tanding of human

behaviors and how they are influenced by economic and other incentives in ways that enhance the

safety, quality, and nutrient value of the food supply.

The AFRI Food Safety Challenge area programs will promote and enhance the scientific discipline of food

safety with an overall aim of protecting consumers from microbial and chemical contaminants that may

occur during all stages of the food chain, from production to consumption. This requires an understanding

of the interdependencies of human, animal, and ecosystem health as it pertains to foodborne pathogens.

A) Improving Food Safety (AFRI Foundational Program) B117

B) Improving the Safety of Fresh and Fresh Cut Produce (AFRI Foundational Program) B116

C) Effective Mitigation Strategies in Antimicrobial Resistance B116

(AFRI Challenge Area Program)

D) Emerging Issues in Food Safety Programs (AFRI Foundational Program) B116

E) Enhancing Food Safety Through Improved Processing Technologies B118

(AFRI Challenge Area Program)

OVERVIEW

Breakout Sessions 1, 2, and 3 - Meeting Rooms B116, B117, and B118

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PROGRAM ABSTRACTS

(Alphabetized by Project Director Last Name)

PATHOGEN AND HOST MECHANISMS INVOLVED IN SALMONELLA

INFECTION OF TOMATO

CRAIG ALTIER (Project Director)

Nugent, S. L.; Meng, F.; Martin, G. B.; Altier, C.

CORNELL UNIVERSITY ITHACA, NEW YORK

Recent years have seen numerous disease cases of salmonellosis caused by the consumption of

produce, with tomatoes being specifically implicated. We investigate here the interaction of plant and pathogen during infection. We find that Salmonella activates the plant immune system primarily due to its recognition of the flg22 region in Salmonella flagellin. The Salmonella flg22 peptide induced the immune

response in leaves that effectively restricted the growth of Salmonella as well as the plant pathogenic bacterium, Pseudomonas syringae pv. tomato. Salmonella multiplied poorly on plant tissues, similar to other bacteria non-pathogenic to plants. However, Salmonella populations increased significantly when

co-inoculated with P. syringae pv. tomato but not when co-inoculated with a type III secretion system mutant of this pathogen. Our results suggest that Salmonella benefits from the immune-suppressing effects of plant pathogenic bacteria, and this growth enhancement may increase the risk of salmonellosis.

To investigate the genetic means by which Salmonella is able to survive and proliferate within tomatoes, we screened for bacterial genes specifically induced after inoculation into ripe tomato fruit. Among these genes, we found 17 members of the previously described anaerobic Fur (ferric uptake regulator) regulon.

To test whether iron acquisition is essential for Salmonella growth in tomatoes, we tested a fepDGC mutant, which lacks the ability to import iron-associated siderophores. This mutant grew significantly more poorly within tomatoes than did the wild type, but the growth defect of the mutant was fully reversed by the addition of exogenous iron, demonstrating the need for bacterial iron scavenging.

REGULATION OF SALMONELLA VIRULENCE BY THE INTESTINAL

ENVIRONMENT

CRAIG ALTIER (Project Director)

Eade, C. R.; Hung, C.; Bullard, B.; Gonzalez-Escobedo, G.; Gunn, J. S.; Altier, C.


Salmonella spp. are carried by agricultural animals, and can subsequently be transmitted to humans via contaminated food or agricultural products. Salmonellae traverse the upper digestive tract and initiate

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tissue invasion at the distal ileum, a virulence process involving the type-three secretion system encoded within Salmonella Pathogenicity Island 1 (SPI1). As this gene expression program is energetically costly,

Salmonellae must coordinate SPI1 expression with anatomical location via environmental cues. We have found that the acetyltransferase Pat and the deacetylase CobB, which together modulate protein N-lysine acylation, regulate SPI1 genes. Regulation of the SPI1 central regulator HilD was essential for Pat and

CobB to exert their effects. The control of HilD by Pat was through post-transcriptional mechanisms, significantly reducing HilD stability while moderately repressing hilD translation. Additionally, growth of Salmonella in the presence of histone deacetylases inhibitors reduced expression of SPI1 in a CobB-

independent manner, suggesting that an acylation/deacylation system plays an important role in invasion control and implying that additional deacylases may exist in Salmonella. We have additionally characterized the mechanism by which bile represses SPI1 expression. Bile acids function synergistically

to achieve the overall repressive activity of bile. We show that the effects of bile and bile acids require HilD and function independently of known upstream signaling pathways. We further show that SPI1 repression by bile acids is also mediated by post-translational destabilization of HilD. These studies

demonstrate a common mechanism by which diverse chemicals inhibit SPI1 expression, and provide the basis for development of therapeutics to repress Salmonella virulence.

EVALUATION OF SAMPLE EFFECTS ON DETECTION OF LISTERIA

MONOCYTOGENES IN SMALL PRODUCE FARMS

PETER BERGHOLZ (Project Director)

Schmidt, K. N. Mann, M. A.; Schmidt, J. P.; Bergholz, P. W.

NORTH DAKOTA STATE UNIVERSITY, VET AND MICRO SCIENCES FARGO, NORTH DAKOTA

L. monocytogenes is a major cause of foodborne illness in the United States an environmentally persistent soil saprotroph. L. monocytogenes prevalence in produce fields can vary spatially from approximately 1% to 50% because produce farms are complex, open systems with each farm comprising

a unique combination of spatial and temporal variables. Predictive modeling of L. monocytogenes contamination risk on farms has been hampered by a lack of reliable data on the population dynamics of this pathogen in the farm environment. Quantitative PCR is a molecular method for quantification of L.

monocytogenes that may address this deficiency. However, the properties of environmental samples can impact quantification of bacterial DNA. We conducted sampling on two privately -owned fresh produce farms in North Dakota and Minnesota. Four types of environmental samples were inoculated with L.

monocytogenes at concentrations ranging between 1,000 - 10,000,000 CFU/g sample. After samples equilibrated, environmental DNA was extracted and L. monocytogenes genomes were quantified by qPCR. DNA extracted from soil and water samples were quantified more precisely than DNA extracted

from surface swabs or leaf/product samples. The data showed a substantial sample effect on L. monocytogenes abundance estimates, with soil displaying approximately 8-64 fold lower L. monocytogenes abundance than water samples.

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ELUCIDATION OF ENVIRONMENTAL FACTORS THAT INFLUENCE

ATTACHMENT OF FOODBORNE PATHOGENS TO BIOTIC AND ABIOTIC

SURFACES

TERESA BERGHOLZ (Project Director)

NORTH DAKOTA STATE UNIVERSITY, VET AND MICRO SCIENCES FARGO, NORTH DAKOTA

Human illnesses linked to consumption of fresh produce have dramatically increased in the last several decades, and produce is now responsible for one quarter of all foodborne outbreaks. Contamination of produce with human pathogens can occur in the pre-harvest environment as well as during post-harvest

handling, and bacterial attachment factors can facilitate persistence of pathogens on produce in both of these environments. Pathogen attachment to surfaces, and subsequent biofilm formation, can significantly reduce efficacy of commonly used decontamination treatments, making these pathogens

harder to eliminate on produce and in the produce processing environment. A number of attachment factors have been described, though limited information is available regarding the regulation and expression of molecular mechanisms that pathogens can use to attach to different surfaces. Exposure to

conditions that would reduce attachment could increase the efficacy of currently used or novel decontamination treatments. In order to develop new methods for controlling foodborne pathogens on fresh produce and in the produce processing environment, further research on the environmental factors that impact attachment of these pathogens is needed. The goal of this proposal is to provide a

comprehensive assessment of pre- and post-harvest environmental factors that influence expression of pathogen attachment mechanisms, and thereby attachment of pathogens to different surfaces. These data will critically inform the development of effective control strategies for pathogens both on produce and during post-harvest handling of produce.

DIFFERENTIAL GENE EXPRESSION INDUCED BY AFLATOXIN B1

CONTAMINATED PEANUT SLURRY IN HEPG2 CELLS

SAMUEL BESONG (Project Director)

Prince G. Boakye, Stephen E. Lumor, Samuel A. Besong

DELAWARE STATE UNIVERSITY DOVER, DELAWARE

Mycotoxins are a major group of toxicants that affect about 25% of the world’s crops, particularly cereals and nuts. Of these, aflatoxins have received the most attention because of their high toxicity and prevalence in cereals and nuts. Even though the effects of these toxins have been extensively studied

using animal models, little is known of their toxicological effects on human cells at sub-pathological doses. Therefore, the purpose of this study is to investigate the effect of aflatoxin B1 on different ial gene expression in human HepG2 cells. In order to achieve our objectives, a serving of peanut slurry

contaminated with sub-pathological doses of aflatoxin will be passed through an in vitro digestion model

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in order to simulate the fate of food through the human gastrointestinal system. After 2 hours, duodenal digests of the contaminated peanut slurry will be introduced into HepG2 cell cultures for 4 hours. This will

be followed by the extraction of mRNA from the cells, and differential gene expression determined using DNA microarray technique. At the end of the study, it is our expectation that by identifying the specific genes that are differentially expressed in the HepG2 cells, we will be able to elucidate the mechanisms of

toxic response or damage by the aflatoxin B1 intoxication at the molecular level.

ENGINEERED NANOMATERIALS IN FRESH CROPS: A FOOD SAFETY

ISSUE?

ACHINTYA BEZBARUAH (Project Director

Bezbaruah, A.N.; Katti, D.; Otte, M.; Katti, K.; Jacob, D.; Gonzalez, J.

NORTH DAKOTA STATE UNIVERSITY FARGO, NORTH DAKOTA

Interactions of Spinacea oleracea (spinach) and Oryza sativa (rice) with zinc oxide nanoparticles (ZnONPs) and single-walled carbon nanotubes (CWCNTs) have been studied at the macro- and

molecular levels using a variety of in-vivo, in-vitro, and modeling experiments. Results indicate that engineered nanomatertials (ENMs) impact plants in growth and at molecular levels including changes of some genetic materials. It is also evident that nanoparticles (ZnONPs) change nutrient uptake by plants which may have great ramification in food and nutrient security and safety. In a parallel study, ENM and

soil bacteria interactions were studied and it was found that some ENMs (nanoiron) facilitate better plant nutrient uptake as compared to when conventional chemical fertilizers are used. Molecular dynamic simulation experiments with rice DNA indicate that proximity of SWCNTs affect DNA. Hydrogen bonds

were broken and new bonds were formed via unzipping of Watson-Crick (WC) nucleobase pairs and wrapping onto ENM when SWCNTs were placed near rice DNA. Apparently Gua and Cyt bases play dominant roles in DNA-SWCNT interactions because we observed a higher number of guanine-cytosine

(Gua-Cyt) WC hydrogen bonds breaking compared to adenine-thymine (Ade-Thy). Experiments are on-going to relate some of the modeling data to actual observations. Additional in-vivo hydroponic and soil based experiments are being conducted in greenhouse settings, and in-vitro cell culture experiments are set up.

TRAINING OF MINORITY STUDENTS IN NUTRIGENOMICS

JUDITH BOATENG (Project Director)

Boateng, J.; Verghese, M.

ALABAMA A & M UNIVERSITY NORMAL, ALABAMA

The primary goal of this proposal is to strengthen the food science undergraduate and graduate programs by introducing a research and teaching concentration in nutrigenomics. The proposal is based on the

strategic mission that Alabama A & M University (AAMU) and other 1890 institutions have placed on providing broader access to innovative technologies in support of standard based teaching and learning.

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The proposal was able to offer summer research experiences to 4 undergraduate students (summer 2014) and is sponsoring the training of a graduate research assistant. Two of the undergraduate students

who participated in the summer program are currently enrolled in the AAMU FS graduate program and will soon begin their research thesis. One other student was accepted for an internship (6 months) to Kellogg this summer, she is expressing interest in AAMU FS graduate program upon her return. So far

two Nutrigenomics courses have been developed and approved for instruction, an undergraduate course-Introduction to Nutrigenomics- FAS 487 and a Graduate course - Applied Nutrigenomics FAS 678 to be offered this fall.

EFFECTS OF ORGANIC ACID-SURFACTANT MIXTURES ON LEVELS OF

BACTERIA AND BEEF QUALITY TRAITS

MICK BOSILEVAC (Project Director)

Mick Bosilevac, Nor Kalchayanand and Andy King

USDA AGRICULTURE RESEARCH SERVICE US MARC CLAY CENTER, NEBRASKA

Introduction: Organic acid efficacy as an antimicrobial treatment of beef carcass surfaces may be increased through the addition of surfactants. However, the effects of antimicrobial-surfactant mixtures on beef quality traits such as flavor and color stability may make their use unacceptable.

Purpose: To identify organic acid-surfactant mixtures that can reduce surface contamination of beef carcasses and that do not adversely affect beef quality.

Methods: The immediate and 48 hour residual efficacy of 2% Citric Acid+0.05% sodium dodecyl sulfate (SDS; CS); 2% levulinic acid+0.05% SDS (LS); and 2% Lactic acid+0.5% Caprylyl/Myristyl Glucoside (LG) were assessed for reduction of aerobic plate counts (APC), Enterobacteriaceae (EB) and inoculated

pathogens (E. coli O157:H7, Salmonella, and Shiga toxin-producing E. coli of serogroups O26, O103, O111, O121 and O145) on beef surfaces (n=20 each treatment). Flavor profile analysis, and color-life during simulated retail display were assessed for steaks cut from non-intact (blade-tenderized) beef subprimals that were treated with commercial food grade mixtures of CS and LS.

Results: The addition of a surfactant only increased the ant imicrobial efficacy of organic acids by approximately 10%. Immediate post-treatment reductions of APC were 0.7, 1.5 and 1.5 log CFU/cm2, and EB were 1.0, 1.3 and 1.2 log CFU/cm2 for CS, LS and LG respectively. The mean reductions of all

pathogens combined were 0.56, 1.46 and 2.02 log CFU/cm2 for CS, LS and LG respectively. Residual chilled 48-hour reductions were generally an additional 0.2 log CFU/cm2 greater than the immediate effect. Statistically significant, but very small in magnitude, differences detected in flavor profiles were not

likely to be of practical importance. Overall color change during simulated retail display did not differ from controls.

Significance: The addition of a surfactant to commonly used organic acids is an inexpensive option that moderately improves antimicrobial efficacy without negatively impacting beef quality.

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IDENTIFICATION OF RISKY FOOD SAFETY PRACTICES AND MICROBIAL

ASSESSMENT OF PRODUCE AT SOUTHWEST VIRGINIA FARMER’S

MARKETS

RENEE BOYER (Project Director)

Boyer, R.; Pollard, S.; di Stefano, J.; Chapman, B.; Ponder, M.; Archibald, T.

VIRGINIA POLYTECHNIC INSTITUTE, FOOD SCIENCE AND TECHNOLOGY BLACKSBURG, VIRGINIA

Fresh produce constitutes 82% of the food sold at farmers’ markets. The high percentage of produce-related foodborne outbreaks and growing number of farmers’ markets selling fresh produce highlights the

need for a food safety focus within these markets. The purpose of this study was to identify current food safety practices and assess the microbial quality of fresh produce sold at Southwest Virginia farmers’ markets. Five farmers’ markets across Southwest Virginia were visited from May – October 2014.

Observational data was collected via a secret shopper model to identify and quantify behaviors considered to be high risk. The microbial quality of produce sold at these markets was also evaluated. Nine different commodities were collected (n=385) from five markets and a chain grocery store. Multiplex

PCR methods were utilized to test for the presence of Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, and Salmonella enterica in the produce samples. Eighty -five percent of produce vendors had no temperature control for cut produce and no vendors used a thermometer. Higher

concentrations (p = 0.0130) of total aerobic bacteria were isolated from produce at farmers’ market than retail (6.73 and 6.16 log CFU/g, respectively). No differences were identified in number of coliforms or Enterobacteriaceae isolated from produce at farmers ’ markets and product purchased at a retail. E. coli

O157:H7, L. monocytogenes and S. aureus was identified in 1.1, 4.8 and 1.1% of farmers’ market and retail produce, respectively; and 4.4, 3.3 and 0.0% of retail produce, respectively.

AN INTEGRATED PLATFORM FOR DETECTION OF BRUCELLOSIS FROM

DAIRY PRODUCT

HSUEH-CHIA CHANG (Project Director)

Shah, S. Senapati, Z. Slouka, Y. Men, F. Klacsmann, F. Mejia and H-C. Chang

UNIVERSITY OF NOTRE DAME NOTRE DAME, INDIANAPOLIS

Real time PCR (rt-PCR), the current gold standard for pathogen detection, is expensive and requires trained personnel and multistep protocol, making it impractical for field applications. The development of

low-cost, turn-key and portable detection platforms for genetic identification has attracted great attention to a wide variety of applications including pathogen diagnostics related to food safety with our current focus on detection of brucellosis. We report an integrated, low-cost, sample-to-answer, selective and

PCR-free biosensing platform for the detection of nucleic acid biomarkers. The integrated microfluidic biochip consists of a sample pretreatment unit to isolate nucleic acids from raw samples and

23

nanomembrane-based molecular sensing/pre-concentration unit. To analyze the raw milk sample, the brucellosis bacteria cell are first captured using antibody functionalized magnetic beads. The Trizol lysed

bacteria captured particles are then loaded on the sample reservoir of the integrated chip. A constant current of 0.8 mA is applied for 15 min to Isolate and concentrate the nucleic acids underneath the sensor. The concentrated target molecules are then allowed to hybridize with a complementary brucella-

specific probe functionalized on the sensor surface. A change in current voltage signal before and after successful hybridization indicated the detection of brucellosis RNA. The versatile platform is also successfully tested against microRNA associated with oral cancer, E.coli and dengue virus with two

mismatch selectivity and fM sensitivity. A portable and push-button instrument that combines the initial treatment of the raw sample using magnetic beads with the integrated biosensing platform is the next prototype currently under development.

MICROBIOLOGICAL EVALUATION OF POULTRY PRODUCT PACKAGES

FROM GROCERY STORES IN NASHVILLE, TENNESSEE

FUR-CHI CHEN (Project Director)

Chen, F.; Godwin, S.; Green, A.; Chowdhury, S.; Stone, R.

TENNESEE STATE UNIVERSITY NASHVILLE, TENNESEE

Introduction: Our previous study indicated that there is a high chance of contamination and transfer of meat juice from packages to hands and food contact surfaces during shopping and handling of raw

poultry products. Further evaluations into the microbiological contamination on the raw poultry packages are necessary for assessments of consumer exposure. Purpose: This study investigated the extent of microbiological contaminations on the surfaces of raw poultry packages purchased from local grocery stores.

Methods: Packages of raw poultry products were purchased from thirty -five grocery stores in metropolitan area of Nashville, Tennessee. Three Packages were purchased from each store including whole chicken, chicken breast, and ground turkey. Information on the brands and packaging types was recorded and

package conditions were inspected to note any leaking of meat juices. Microbiological contaminations on the packages were evaluated.

Results: Of the 105 packages, 24 had aerobic plate count (APC) higher than 106 CFU on the packages and 18 had coliform count (CF) and 8 had E. coli count (EC) higher than 103 CFU on the packages.

Campylobacter was found on 7 and pathogenic E. coli was found on 6 of the packages while no Salmonella was found. There was no significant difference on the bacteria counts among the product and package types. However, leaking packages had higher bacteria counts; the average APC, CF, and EC

were 3.9 x106, 1.3x103, and 4.2x102 CFU, respectively. Of the 8 leaking packages, 5 had either Campylobacter or pathogenic E. coli and 2 had both found on the surfaces. Significance: Campylobacter and pathogenic E. coli are more often found on poultry packages than Salmonella. Leaking packages clearly increase the risk of cross contamination.

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ATMOSPHERIC COLD PLASMA INACTIVATION OF NOROVIRUS

SURROGATES AND NATIVE MICROBIOTA ON BLUEBERRIES

HAIQIANG CHEN (Project Director)

Niemira, B. A.; Lacome, A.; Gurtler, J.; Sites, J.; Boyd, G.; Li, X.; Chen, H.; Fan,

X.; Kingsley, D.

UNIVERSITY OF DELAWARE NEWARK, DELAWARE

Cold plasma (CP) is an emerging, novel, nonthermal technology that can be used for surface decontamination of foods. This study investigated CP technology for the nonthermal inactivation of the human norovirus surrogates, Tulane virus (TV) and Murine Norovirus (MNV), as well as for background

microbiota on the surface of blueberries. Blueberries (5 g) were weighed into sterile 4 oz. glass jars and inoculated with 500 μl of TV or MNV (5 log PFU/g). Samples were treated with atmospheric CP for 0, 15, 30, 45, and 60 s at a working distance of 7.5 cm with 7 cubic feet/minute (cfm) of circulating air. CP

demonstrated significant antiviral efficacy against TV, with a reduction of 1.6 log PFU/g after 45s. In comparison, a 15 s treatment of CP reduced MNV by, a 1 log PFU/g. Blueberries were analyzed for compression firmness, surface color, and total anthocyanins, immediately after each treatment. CP

resulted in significant (P < 0.05) reductions of APC on treated berries, with a 1.6 log CFU/g reduction after a 90 s CP treatment. All CP treatments resulted in suppression of microbiota during storage. After 7 days of storage, the APC of blueberries treated with the shortest CP exposure (15 s) were 2 log CFU/g lower

than the control. CP treatments longer than 60 s resulted in significant reduction in berry firmness. Total anthocyanins and overall color intensity (L*, a*, and b*) were reduced by 120s oc CP treatment. With further optimization, CP may be used by food processors as a means to inactivate foodborne viruses.

VARIABLE HIGH PRESSURE PROCESSING SENSITIVITIES FOR GII HUMAN

NOROVIRUSES


Lou, F.; Li, X.; Dai, X.; Ma, Y.; DiCaprio, E.; Hughes, J.; Chen, H.; Kingsley, D.;

Li, J.

THE OHIO STATE UNIVERSITY COLUMBUS, OHIO

Human norovirus (HuNoV) is the leading cause of foodborne diseases worldwide. High pressure

processing (HPP) is one of the most promising non-thermal technologies for decontamination of viral pathogens in foods. However, the survival of HuNoVs by HPP is poorly understood because these viruses cannot be propagated in vitro. In this study, we estimated the survival of different HuNoV strains

within the GII genogroup after HPP treatment using viral receptor-binding ability as an indicator. Four

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HuNoV strains (one GII.1 strain, two GII.4 strains, and one GII.6 strain) were treated by high pressure ranging from 200-600 MegaPascal (MPa). After treatment, the intact viral particles were captured by

porcine gastric mucin-conjugated magnetic beads (PGM-MBs) which contain histo-blood group antigens, the functional receptors for HuNoVs. The genomic RNA copies of the captured HuNoVs were quantified by real-time RT-PCR. It was found that two GII.4 HuNoVs had similar sensitivity to HPP. The

susceptibilities of HuNoV strains against HPP ranked as GII.4 > GII.6 > GII.1, with GII.4 being the most sensitive. Evaluation of temperature and matrix effects on HPP-mediated inactivation of HuNoV GII.4 strain showed that HuNoV GII.4 was more easily inactivated at lower temperature and at neutral pH. In

addition, PBS and Minimal Essential Medium (MEM) can provide protective effects on HuNoV inactivation as compared to H2O. Collectively, this study demonstrated that (i) different human NoV strains within the GII genogroup exhibited different sensitivities to high pressure; and (ii) HPP is capable of inactivating human NoV GII.4 strains by optimizing pressure parameters

EFFICACY OF LOW-TEMPERATURE HIGH HYDROSTATIC PRESSURE

PROCESSING IN INACTIVATING VIBRIO PARAHAEMOLYTICUS IN OYSTER

HOMOGENATE


Phuvasate, S.; Su, Y.

OREGON STATE UNIVERSITY CORVALLIS, OREGON

Culture suspensions of five clinical Vibrio parahaemolyticus strains in 2% NaCl solution were subjected to

high pressure processing (HPP) under various conditions (200–300 MPa for 5 and 10 min at 1.5–20°C) to study differences in pressure resistance among the strains. The most pressure-resistant and pressure-sensitive strains were selected to investigate the effects of low temperatures (15, 5 and 1.5°C) on HPP

(200 or 250 MPa for 5 min) to inactivate V. parahaemolyticus in sterile oyster homogenates. Inactivation of V. parahaemolyticus cells in culture suspensions and oyster homogenates was greatly enhanced by lowering the processing temperature from 15 to 5 or 1.5°C. A treatment of oyster homogenates at 250

MPa for 5 min at 5°C decreased the populations of V. parahaemolyticus by greater than 6.2 log CFU/g. Decreasing the processing temperature of the same treatment to 1.5°C reduced all the V. parahaemolyticus strains inoculated to oyster homogenates to non-detectable (<10 CFU/g) levels.

Factors including pressure level, processing temperature and time all need to be considered for developing effective HPP for eliminating pathogens from foods.

26

ATTACHMENT ABILITY OF SHIGA TOXIN-PRODUCING ESCHERICHIA COLI

TO ALFALFA, LETTUCE, TOMATO AND FENUGREEK SEEDS

JINRU CHEN (Project Director)

Yue Cui, Ronald Walcott, Jinru Chen

UNIVERSITY OF GEORGIA ATHENS, GEORGIA

Introduction: Outbreaks of Shiga toxin-producing Escherichia coli (STEC) infection have been linked to

the consumption of contaminated fresh produce such as lettuce, and alfalfa and fenugreek sprouts. In several incidences, contaminated seeds were suspected as the source of the responsible pathogens.

Purpose: To compare the attachment abilities of different STEC strains to vegetable seeds with different surface integrity properties and chemical treatment practices.

Methods: Two different levels of nalidixic acid (NA) resistant cells of O157:H7 (F, K and H) and O104:H4

(G) strains were co-incubated with mechanically damaged and intact, as well as chemically treated and untreated, alfalfa, fenugreek, tomato and lettuce seeds at room temperature for 5 h. Contaminated seeds were rinsed with sterile water then soaked overnight in phosphate buffered saline at 4oC. Seed soaking

solutions were plated onto tryptic soy agar (TSA) as well as TSA and sorbitol MacConkey agar supplemented with NA. Pathogen attachment rate was expressed as the ratio of the number of attached cells to number of noculated cells. Fisher’s least significant difference test was used to determine the significance of difference among the tested pathogens on different vegetable seeds.

Result: Overall, the number of attached STEC cells was the highest (10.4%) on lettuce seed, followed by tomato (4.8%), alfalfa (2.5%) and fenugreek (1.8%) seeds. The ability of STEC cells to attach to the damaged seeds (6.4%) was significantly higher (p<0.05) than to intact seeds (3.3%) whereas no

significant difference was observed between pathogen attachment to chemically treated vs. untreated seeds. Strain K displayed the best attachment ability on the tested seeds (12.5%), followed by F (5.2%), H (1.5%) and G (0.2%).

Significance: This work highlights the difference in attachment ability of STEC strains on various

vegetable seeds. The rate of STEC attachment was influenced by seed surface integrity and chemical treatment practice.

27

ATTACHMENT OF VARIOUS SEROVARS OF SALMONELLA ENTERICA TO

VEGETABLE SEEDS WITH DIFFERENT SURFACE CHARACTERISTICS

JINRU CHEN (Project Director)

Yue Cui, Ronald Walcott, Jinru Chen

UNIVERSITY OF GEORGIA ATHENS, GEORGIA

Introduction: Numerous outbreaks of foodborne illness have been linked to the consumption of

contaminated fresh produce and contaminated seed is a potential source of foodborne pathogens such as Salmonella.

Purpose: To assess the attachment abilities of Salmonella to vegetables seeds with different surface characteristics.

Methods: Chemically treated vs. untreated and intact vs. mechanically damaged seeds of alfalfa,

fenugreek, tomato and lettuce were artificially contaminated with nalidixic acid resistant cells of 4 Salmonella strains at 20oC for 5 h. Contaminated seeds were rinsed twice with 10 ml of sterile water and then soaked overnight in 5 ml of phosphate buffered saline (pH 7.40) at 4oC. Seeds were then vortexed

vigorously, and seed soaking solutions were plated onto bismuth sulfite agar, tryptic soy agar (TSA) and TSA supplemented with nalidixic acid. The ratio of the number of attached cells to the number of inoculated cells was reported as attachment rate. Student t tests were performed to determine the significance of differences among each pathogen attached to each type of seeds.

MICROFLUIDICS AND PHYSICS-BASED APPROACHES TO ELUCIDATE

PHYSICAL MECHANISMS OF FRESH PRODUCE CONTAMINATION

ASHIM DATTA (Project Director)

Warning, A.; Datta, A.


The chilling of warm, fresh fruits and vegetables (produce) to extend their shelf life increases the opportunities for contamination by pathogenic bacteria through openings in the surface suc h as stem scars, wounds, or stomata. Chilling generates a negative pressure differential between the interior of the

produce and chilling water due to the condensation of water vapor inside the produce that creates a vacuum. While experiments in literature have shown that this mechanism is positively correlated with contamination, other experiments have shown it may not be the only cause. This work uses a tomato as a

representative system. Using a 3D porous medium based transport model on a MRI acquired real geometry, a mechanistic understanding for the first time. The model simulates the transport of water vapor, liquid water, bacteria, and energy considering convection-diffusion processes. The model is

validated experimentally for overall change in weight, spatial moisture, core temperature, and core

28

pressure. Results show that there is a less than one percent change in weight after 30 minutes regardless of temperature differential with the smallest change at zero temperature differential. The temperature

differential, rate of cooling, and permeability dictates how water infiltrates into the tomato. At low temperature differentials, water transport is diffusion dominated while at higher temperature differentials, water is transported by convection. As the temperature differential increases, the pressure gradient

increases as well between the surface and center creating a high inflow velocity. A 30C temperature differential increased bacteria penetration depth and count by a factor of 10 over 30 minutes.

INFLUENCE OF HEAT TRANSFER WITH DIFFERENT CONTAINER SIZE ON

MEASURED THERMAL INACTIVATION PARAMETERS OF HEPATITIS A

VIRUS

MICHAEL DAVIDSON (Project Director)

Bozkurt, H.; D’Souza, D. H.; Davidson, P. M.

UNIVERSITY OF TENNESSEE, KNOXVILLE KNOXVILLE, TENNESSEE

Mathematical models to predict thermal inactivation of foodborne pathogens assist in developing adequate thermal processes. The correct understanding of the thermal inactivation kinetics of viruses will allow precise determination of the thermal process conditions. The purpose of this study was to

investigate the influence of heat transfer with different container size on measured thermal inactivation kinetic parameters of hepatitis A virus (HAV). Three different container sizes, (tubes with 3 and 12 mm diameter, and moisture barrier plastic vacuum bags, 13 cm x 19 cm) were used in the heat treatments at

50, 56, 60, 65, and 72°C. A numerical model was developed to evaluate the effect of transient heat transfer behavior in different container size on microbial inactivation for HAV. The prediction of microbial reduction in different containers were investigated by using first-order and Weibull model. The

temperature distribution obtained with the proposed numerical model indicated that the temperatures of the 3-mm tubes and moisture barrier plastic vacuum bags increased rapidly to the set -point temperature, but the sample temperature increased gradually from the outer layer to the center because of slow

conduction for 13 mm tubes. The results indicated that the shapes of the inactivation curves of HAV for the temperature studied (50-72°C) were characterized by an initial drop in viral counts followed by a tailing behavior. A broad tailing behavior was observed in the survival curves, and the tail for the 12-mm

tubes was larger than that for the 3-mm tubes and moisture barrier plastic vacuum bags. The proposed numerical solution could be used for predicting the thermal inactivation behavior of foodborne enteric viruses in foods with different container size. The results of this study might contribute to the development

of appropriate thermal processing conditions for foodborne enteric viruses to ensure safe food for human consumption.

Key words: Hepatitis A virus; mathematical model, numerical methods, heat transfer, container size.

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INTERNALIZATION OF SALMONELLA IN ARACHIS HYPOGAEA, PEANUT

PLANTS AND SEED POD

FRANCISCO DIEZ-GONZALEZ (Project Director)

Rossbach, J. D.; Freund, B.; Nitti, M.; Schneider, O.; Fink, R. C.; Sadowsky, M.

J.; Tong, C.; Diez-Gonzalez, F.

UNIVERSITY OF MINNESOTA ST. PAUL, MINNESOTA

Outbreaks of Salmonella in peanut products has led scientist to investigate the routes of contamination. One potential route is the internalization of Salmonella cells into peanut plants and seedpods from soil.

The objective of this research was to identify the possible routes of Salmonella internalization into peanut seedpods and plant tissues.

The internalization of Salmonella Typhimurium was studied by exposing peanut seedpods to cell

suspensions and inoculated soil containing 7.0 log CFU/g. For soil experiments, moisture level and soil type were studied. Internalized cells were determined by swabbing and rinsing the interior surfaces of the seedpods. External and internalized cells were quantified using differential media. Peanut plants were also grown in inoculated soil and the presence of Salmonella in plant tissues was determined.

Using cell suspensions, the average count of internalized cells after 22 h ranged from 3.4 log CFU/pod at 16°C to 6.4 log CFU/pod at 37°C which resulted in rates of internalization of 0.07 and 13.7%, respectively. This trend was consistent with 4-h exposure. Pods exposed to Salmonella-inoculated soils

at <10% moisture content had no detectable (<10 CFU/pod) internalized cells, but when water content was >15% the mean internal count was 4.2 log CFU/pod. Plants that were seeded in inoculated soils had detectable levels of Salmonella inside of roots and stems.

This work suggests that peanut seed pods and whole plants are susceptible to Salmonella infiltration, which indicates an entry point into a peanut processing facility from the growing field.

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THERMAL RESISTANCE OF SALMONELLA IN DRY EXTRUDED CEREALS:

KINETIC PARAMETERS AND THE ROLE OF IRON CONTENT

FRANCISCO DIEZ-GONZALEZ (Project Director)

Maserati, A.; Fink, R. C.; Lourenco, A.; Diez-Gonzalez, F.

UNIVERSITY OF MINNESOTA ST. PAUL, MINNESOTA

Salmonella causes the largest number of outbreak-related hospitalizations and is the second cause for single-etiology outbreaks and illnesses. Recently, Salmonella outbreaks have been associated with low moisture foods previously considered safe from pathogen contamination.

Based on this emerging trend, the goal of this project is to determine physiological and molecular mechanisms that contribute to the ability of Salmonella to survive desiccation and develop thermal tolerance.

Transcriptional changes induced by desiccation were determined equilibrating samples to water activity of 0.11 and 1.0 (as control condition) and extracting total RNA for direct RNA sequencing. Genes were

classified according to the Kegg Orthology (KO) Database. We found 290 genes up-regulated in desiccated cells compared to control condition cells. According to the KO classification, most of these genes belong to metabolic pathways, genetic information processing and environmental information

processing, suggesting that the cells are adapting to desiccation and DNA repair/damage control may be necessary for a prompt recovery after moist conditions are restored. Decimal reduction values (D-values) at different temperatures were determined on a food matrix (toasted

oat cereal) at water activity 0.11 and 1.0. To evaluate the impact of the food matrix on the effectiveness of thermal treatment and to set standard procedures for testing of different chemicals (e.g. chelating agents), we also determined D-values at the same water activities on inert material (micro glass-beads).

Our results will provide valuable information on the impact the food matrix has on thermal resistance and on the molecular mechanisms triggering it.

ACCUMULATION OF ENGINEERED NANOPARTICLES IN PLANT FOODS:

NUTRITIONAL BIOACCESSIBILITY AND DIETARY EXPOSURE RISKS

STEPHEN EBBS (Project Director)

Ebbs, S. D.; Bradfield, S.; Ma, X.

SOUTHERN ILLINOIS UNIVERSITY

CARBONDALE, ILLINOIS

The release of engineered nanomaterials (ENMs) into the environment has raised serious concerns about

their potential risks to food safety and human health. There is a particular need to determine the extent of

31

ENM uptake into plant foods. Two set of studies are underway to evaluate the ENM accumulation in

various plant foods. A systematic evaluation of the accumulation of six different ENMs into the tissues of

ten common below ground vegetables is underway to identify those with the greatest potential for ENM

accumulation. Additional efforts will use the vegetables produced to examine how basic food preparation

steps alter ENM dietary exposure and to estimate the nutritional bioaccessibility of the ENMs from those

tissues. Separate studies are utilizing leaf and stem vegetables and a limited array of seed crop species

to examine how modes of ENM exposure promote accumulation in edible tissues. Dietary exposure

modeling is being planned for all of the plant species under study to quantify risks of ENM ex posure. The

nutritional bioaccessibility of the ENM will be demonstrated and models projecting dietary exposures will

be produced to provide a comprehensive picture of the food safety risk posed by these ENMs. Results

from this work are expected to help growers, extension agents, and government agencies to make sound

decisions on choice of crops for particular ENM-impacted soils. The specific accumulation and dietary

exposure scenarios associated with particular ENM and plant combinations would allow for

recommendations concerning which ENM-containing products can be safely applied to human food

crops.

MODELS FOR THE SURVIVAL OF SALMONELLA IN LOW-WATER ACTIVITY,

HIGH FAT FOOD SYSTEMS AT 80C

JOSEPH FRANK (Project Director)

Trimble, L.; Barnes, S.; Frank, J.

UNIVERSITY OF GEORGIA

ATHENS, GEORGIA

Salmonella has demonstrated an enhanced resistance to thermal inactivation and the ability to survive for long

periods of time in dry foods containing fat. The aim of this study was to develop mathematical models that will

predict the behavior of Salmonella in high fat, low water activity (aw) foods held at 80°C. Whey protein isolate

powder was homogenized with peanut oil to achieve 20% and 50% (w/w) fat concentrations and was

equilibrated to target aw levels < 0.60. A dried cocktail of Salmonella was inoculated, vacuum-sealed and

treated at 80 °C for 11 time points up to 48h. The Weibull model provided the best description of the data ((f

test< F table), R2adj, RMSE) and was selected for secondary modeling. Secondary models were developed using

multiple linear regression and were validated in toasted oat cereal, animal crackers, chia powder and natural

peanut butter.

Survival significantly increased with decreasing aw. Fat content did not significantly influence survival.

Prediction of survival using secondary models provided 40% of the model residuals in the acceptable zone and

a correlation coefficient of R=0.49. The % bias and % discrepancy results (-6% and 27%) are consistent with

those inherent in the secondary models (0.01% and 3%). The % bias results showed that the developed

models had similar accuracy in predicting survival in high fat foods (-7%) and low fat foods (-6%). The models

developed in this study provide information that can be used in risk mitigation strategies for Salmonella in low

aw foods.

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NON-EQUILIBRIUM PLASMA-ACTIVATED WATER IN AGRICULTURE:

PATHOGEN CONTROL, PLANT GROWTH ENHANCEMENT, AND

REDUCTION OF IRRIGATION WATER CONSUMPTION

ALEXANDER FRIDMAN (Project Director)

Fridman, G.; Miller, V.; Rabinovich, A.; Fridman, A

DREXEL UNIVERSITY

PHILADELPHIA, PENNSYLVANIA.

Developments over the last 30+ years in plasma-microelectronics resulted in many breakthroughs and, in

particular, cold non-equilibrium plasma treatment of various liquids. The specific examples include

application of plasma-activated biological medium in medicine (especially in cancer treatments),

application of liquid-plasmas in fabrication of metamaterials, micro-plasma modification of liquid fuels, etc.

However, most of these applications are limited to small amounts of liquid due to relatively low power of

non-equilibrium cold plasma systems that were initially applied for these purposes. Significant

breakthrough in this direction happened during the last 3-5 years with introduction of transitional non-

equilibrium plasmas (like the non-equilibrium gliding arc discharges and the non-equilibrium pulsed power

plasma systems). This opened the possibility of generating cold atmospheric plasmas at relatively high

power levels, sufficient to treat large volume of liquid. This, in turn, triggered possibility of large-scale

applications of plasma-activated water (of sufficiently-high water volume) for sterilization, washing, seed

germination, plant growth stimulation, etc, which has an important impact in food safety and agricultural

applications.

ENHANCING FARMERS MARKET FOOD SAFETY PRACTICES FOR FRESH

PRODUCE HANDLING

KRISTIN GIBSON (Project Director)

Gibson, K.; Wright, K.; Sirsat, S.; Neal, J.

UNIVERSITY OF ARKANSAS

FAYETTEVILLE, ARKANSAS

Consumer support for the local food movement and farmers markets (FM) has grown exponentially since

2006. FM vendors and managers need to ensure that appropriate GHPs and BMPs are followed so their

product is safe for human consumption. However, the resource base for FM food safety is fragmented,

generalized, and difficult to navigate. Additionally, novel approaches are needed to engage consumers in

market food safety. The overall goal of this project is to equip vendors, market managers, and consumers

with both scientifically-based and practical behaviors that will reduce the likelihood of a foodborne

outbreak. We will achieve this goal through the following objectives:

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1. Conduct focus groups with FM vendors and managers to determine current implementation of food

safety training materials.

2. Conduct surveys and focus groups with FM consumers to identify perceptions of market food safety

and local fresh produce.

3. Determine the most effective FM vendor booth configuration to prevent cross -contamination.

4. Develop a dynamic resource to link local jurisdiction requirements.

5. Develop web and smartphone accessible food safety materials utilizing QR codes and augmented

reality.

UNDERSTANDING SALMONELLA-TOMATO PLANT HOST INTERACTIONS

AND DEVELOPMENT OF NOVEL EFFECTIVE CONTROL STRATEGIES TO

REDUCE SALMONELLA BURDEN IN TOMATO

RAJASHEKARA GIRESH (Project Director)

Deblais I, L.; Gurel, F.; Miller, S.; Rajashekara, G.

OHIO STATE UNIVERSITY

WOOSTER, OHIO

Understanding and anticipation are important steps in the management of foodborne outbreaks. This is

especially true since the discovery in 2006 of asymptomatically colonized tomato plants and fruits by

Salmonella typhimurium. More over, contamination can result in internalization of the pathogen thus

rendering it immune to subsequent decontamination. Comprehension of environmental factors controlling

the interaction between tomato plants and S. typhimurium, and identification of effective control methods

are a priority for preventing new epidemics. Three-week-old tomato plants were sprayed with a

suspension of S. typhimurium, or cotyledons were clipped with scissors contaminated with the pathogen.

Grown at high relative humidity (80%) and low temperature settings (20°C/ 15°C, 12H light/ 12H dark),

survival in planta of S. typhimurium populations was studied weekly until the ripening stage through

bacterial quantification in plant tissues on XLT-4 agar medium. The first week following spray inoculation,

S. typhimurium survived in the phyllosphere of all inoculated tissues; however, the pathogen was

detected internally only in foliar tissues. Fourteen days post-inoculation, S. typhimurium was detected on

the surface and inside inoculated leaves, and its population stabilized at a density of 106 CFU per plant,

without migration of the bacteria into the stem. Fourteen days after cotyledon inoculation by clipping, the

bacterial population stabilized at a density of 105 CFU per plant. S. typhimurium was still restricted to the

inoculation point despite a significant increase of the internal population 21 days after the introduction of

the pathogen. A library of 4182 small molecules was screened against S. typhimurium. Eleven small

molecules killed S. typhimurium with a minimal inhibitory concentration between 5 μM and 400 μM, and

seven of these were bactericidal against multiple Salmonella serotypes. This is the first investigation to

demonstrate the inability of S. typhimurium to colonize tomato at high relative humidity and low

34

temperature. Further, despite the broad range of resistance of S. typhimurium to antimicrobials, promising

anti- S. typhimurium candidates were found.

ASSESSMENT OF TEMPERATURE AT RECOMMENDED METHODS OF

DETERMINING DONENESS IN EGG RECIPES

SANDRIA GODWIN (Project Director)

Godwin, S.; Stone, R.; Troupe-Austin, L.; Maughan, C.; Chambers, E.

TENNESSEE STATE UNIVERSITY

NASHVILLE, TENNESSEE

Egg dishes should be cooked to 160°F IT. However, a nationwide survey found that few consumers used

a food thermometer when preparing egg dishes. Methods for determining doneness included: time,

firmness of product, product jiggling, color, or cleanliness of inserted instrument. To assess the potential

safety of reported methods for determining doneness, chess pies, quiche, and breakfast casseroles were

prepared. Researchers recorded time required to reach and consistency at 160°F, temperature upon

completion of recommended cooking time, and time to doneness. Pies and quiche reached 160°F before

the recommended cooking time but were still liquid. Upon completion of the recommended cooking time

the products were set, had browned, and the knife and toothpick came out clean. The breakfast

casserole failed to reach 160°F within the recommended cooking time and was still liquid. The dish had

to be cooked approximately 12 minutes more before reaching160°F. At 160°F the casseroles were set,

both the knife and toothpick came out clean and they were light brown in color. Methods used by

consumers to determine doneness of quiche and pies containing eggs appear to be safe; breakfast

casseroles needed to be cooked longer than the recommended time. Temperatures should be check for

all products to ensure safety.

CONSUMER AWARENESS OF AND RESPONSE TO SAFETY ISSUES UPON

DELIVERY OF MEAT, FISH AND/OR SEAFOOD PURCHASED ONLINE

SANDRIA GODWIN (Project Director)

Godwin, S.; Stone, R.; Senger-Mersich, A.; Hallman, W.



Approximately 500 US companies market fresh or frozen meat, fish, and/or seafood directly to consumers

online. The perishable nature of these products increases the potential for foodborne illness. Problems

reported by consumers when receiving products ordered online, and the subsequent actions taken by the

vendor were assessed. A nationally representative sample of 951 adults who had purchased or received

35

gifts of perishable meat, fish, and/or seafood products ordered from online vendors completed a Web-

based survey. Few consumers who recalled seeing contact information on company websites contacted

the company to report a problem with their order. Most common problems included: order did not arrive

at scheduled time, order was incorrect, and recipient was unhappy with the products. A common action

taken by the company was to replace the unsatisfactory items. Four percent of consumers believed the

delivered items were not cold enough upon arrival; only 21.2% used a thermometer to test the

temperature. Most kept the items they believed were not cold enough. Consumers place themselves at

risk by not checking temperatures of products upon delivery. Findings suggest consumers believe they

have encountered few problems with ordering and receiving perishable products from online companies.

SERS DETECTION AND CHARACTERIZATION OF GOLD NANOPARTICLES

ON AND IN SPINACH LEAVES

LILI HE (Project Director)

Zhiyun Zhang and Lili He

UNIVERSITY OF MASSACHUSETTS

AMHERST, MASSACHUSETTS

The increased prevalence of engineered nanomaterials in the environment and their potential tox icity

urge researchers to study whether those engineered nanomaterials could possibly contaminate

agricultural food products. However, many techniques require invasive and complicated sample

preparation procedures to detect and characterize engineered nanomaterials. In this study, we aim to

explore the feasibility of surface enhanced Raman spectroscopic (SERS) mapping technique to detect

and characterize gold nanoparticles (Au NPs), as the model engineered nanomaterials, on and in spinach

leaves. We prepared various sizes of citrate coated Au NPs (15, 50, 90, and 150 nm) and incubated

them with spinach leaves. For Au NPs attached on the surfaces, we were able to detect the clearly

enhanced signals from Au NPs of 50 to 150 nm at 50 and 5 ppm. Peak charac terizations revealed the

aggregation status of Au NPs and their interactions with plant biomolecules such as chlorophylls and

beta-carotenes. The 90 nm Au Nps produced strongest signals compared to the other sizes of Au NPs.

For Au NPs penetrated into the leaves, we noticed a size dependent penetration behavior of Au NPs from

the size 50 to to 150 nm. These results demonstrated that SERS mapping is able to detect and

characterize the Au NPs of different sizes on and in plant tissues.

36

DEVELOPMENT AND TRANSFER OF DISINFECTION BY-PRODUCTS INTO

FRESH AND FRESH-CUT PRODUCE AND IMPACT ON DISINFECTION

EFFICACY

CHING-HUA HUANG (Project Director)

Wan-Ning Lee; Xi Chen, Yen-Con Hung; Ching-Hua Huang

GEORGIA INSTITUTE OF TECHNOLOGY

ATLANTA, GEORGIA

Chlorine-containing disinfectants are widely used in the processing of fresh and fresh-cut produce.

However, significant knowledge gaps still exist regarding the formation, identities and quantities of

disinfection by-products (DBPs) generated as food residues or in the processing water. This project

addresses this issue by investigating many conventional and emerging DBPs of concern for their

mechanisms of formation and transfer into fresh and fresh-cut produce after chlorine-based disinfection

methods (sodium hypochlorite, chlorine dioxide and electrolyzed oxidizing water), and for their impact on

the efficacy in inactivating pathogens. Six specificresearch objectives are included: (1) Improve/develop

analytical methods for measuring conventional and emerging DBPs in process water and produce; (2)

Prioritize DBPs based on screening of their concentrations after typical chlorine disinfection for produce;

(3) Evaluate the formation of DBPs and impact on microbial inactivation efficacy due to different

disinfectants, produce, disinfection conditions and operational parameters; (4) Evaluate the stability and

transfer of DBPs in and between water and produce; (5) Elucidate the mechanisms of DBP formation

from organic precursors in produce; and (6) Develop effective disinfection strategies of high microbial

inactivation efficacy and minimized DBP formation for fresh and fresh-cut produce. Results of this project

will be very useful for the produce industry to better understand the risks of food-borne DBPs and develop

strategies to improve current sanitation processes. They will also contribute to the long-term sustainability

of food production systems by providing safer products, reducing improper usage of hazardous chemical

disinfectants, and reducing contamination in food processing water.

37

NOVEL ELECTROLYZED OXIDIZING WATER BASED CLEANING-IN-PLACE

MEAT GRINDER SANITIZATION PROCESS DEVELOPMENT AND

OPTIMIZATION

YEN-CON HUNG (Project Director)

Ravi Jadejal and Yen-Con Hung

UNIVERSITY OF GEORGIA, ATHENS, GEORGIA

This study was designed to develop and optimize an electrolyzed oxidizing water based Cleaning- In-Place method for meat grinders. This experiment was conducted in three parts; 1) Optimum amount of

electrolyzed oxidizing water ice (EO ice-prepared from 200 mg/L chlorine containing EO water, 250,500 and 1000 g) to reduce Escherichia coli O157:H7 from inoculated meat grinders , 2) Antimicrobial potential of various combinations of EO ice and EO water (150 mg/L free chlorine 1000 g EO ice + 200, 400 or 600

ml EO water) to reduce pathogen from inoculated meat grinder and 3) Efficacy of EO ice+ EO water treatment to reduce E. coli O157:H7 or Salmonella Typhimurium DT 104 from the meat grinders inoculated by processing beef containing approximately 6 or 3 log CFU/g pathogen. In each study, five

200 g uninoculated beef pieces were ground and collected after each treatment. Efficacies of EO ice based treatments were compared with Deionized water ice (DI ice) and no treatment controls. EO ice, DI ice and no treatment control treatments yielded E. coli O157:H7 recoveries ranging from 4.05 to 1.92,

4.32 to 2.76 and 5.40 to 3.12 log CFU/g from ground beef samples 1 to 5, respectively. EO ice and EO water combination treatments further decreased E. coli O157:H7 and after 1000 g EO ice with 600 ml EO water reduced the cross-contamination in all ground beef samples with the E. coli O157:H7 and

recoveries ranging from 2.43 to <1 log CFU/g were obtained. In the last part, when grinders were inoculated with low levels of pathogens, 1000 g EO ice +600 ml EO water treatment completely eliminated E. coli O157:H7 and S. Typhimurium DT 104 cross-contamination. Recoveries from the

grinders inoculated with higher level of pathogens were 3.52 to <1 and 3.06 to <1 log CFU/g in ground beef samples 1 to 5 for E. coli O157:H7 and S. Typhimurium DT 104, respectively.

INVESTIGATION OF FOOD-BORNE VIRUSES DISINFECTION BY UV-A

ACTIVATED TI02-COATED SURFACES


Lingling Liu, Kranti Yemmireddy, Yen-con Hung, Jennifer L Cannon


TiO2 nanoparticles can generate strong photocatalytic activity under UV-A light, which can degrade

organic molecules for cleaning and disinfection purposes. However, research is lacking in applying TiO2 for foodborne viruses disinfection. Among foodborne outbreaks, human norovirus (HuNoV) and hepatitis -A virus (HAV) are two major concerns since they are very resistant to disinfection. In this study, murine

norovirus (MNV-1) was used as a surrogate for HuNoV which is non-culturable. A polyurethane binder

38

was used to mix with TiO2 powder in order to attain a stable coating on indented stainless steel surfaces. Viral titers were determined by plaque assay and RT-PCR before and after treatment. 300 uL of purified

MNV-1 or HAV with titers of 8.68 log (PFU/mL) or 5.52 log (PFU/mL) respectively, were inoculated onto each coupon. 5.53 log PFU/coupon and 0.52 log gc/coupon MNV-1 reductions could be achieved with TiO2 coated surfaces with a 8100 mJ/cm2 UV-A dose, while 4.2 log PFU/ coupon and 0.54 log gc/

coupon HAV reductions were achieved with a 13500 mJ/cm2 UV-A dose. However, without TiO2 or without UV-A, little reductions in virus infectivity were achieved. Similar results were achieved by methylene blue photocatalytic decay rate experiments, which showed that TiO2 coated surfaces had

much higher photocatalytic activities than binder-coated or plain stainless steel surfaces alone. Thus TiO2 is an effective disinfectant of foodborne viruses when activated by UV-A, but long exposure times are required. With further development, photocatalytic disinfection with TiO2, could be applied to equipment used in food processing to prevent cross-contamination by foodborne viruses.

ANTIMICROBIAL INTERVENTIONS FOR BLADE TENDERIZED WHOLE

MUSCLE NON-INTACT BEEF STRIP LOINS: EVALUATION OF SHELF-LIFE

AND SENSORY CHARACTERISTICS


R.J. Kersey, A.M. Stelzleni


The objective of this study was to evaluate antimicrobial interventions on the quality and sensory

characteristics of steaks from blade tenderized beef. Sixty boneless beef strip loins were assigned to one

of five treatments: Electrolyzed oxidizing water (pH 6.2-6.5, 50 ppm free chlorine; EOW), 0.2% levulinic

acid plus 0.02% sodium dodecyl sulfate (LVA+SDS), peroxyacetic acid (200 ppm; PAA), lactic acid (4.5%;

LA), and a control (CON). Treatments were applied using an automated sanitizing cabinet. Following

treatment, subprimals were mechanically tenderized. Subprimals were vacuum packaged, boxed, and

held for 4 days to simulate transportation and storage. Subsequently, loins were cut into steaks and

randomly assigned 0, 1, 3, 5, or 7 days of aerobic shelf-life. Additionally, two steaks were selected for

sensory and shear force analysis. Steaks were collected on respective shelf life days for aerobic plate

count and lipid oxidation. Trained subjective color and objective color were recorded on day 7 steaks.

PAA and LA retarded (P<0.05) psychrotrophic organism growth more than EOW, LVA+SDS, and CON.

There was no difference in lipid oxidation (P>0.05) and objective color (P>0.05) among treatments. PAA

had the largest percentage of surface discoloration; however by day 5 all treatments were similar

(P>0.05). By day 7 LA (P<0.05) had lower WPC scores than EOW and PAA but was similar to CON

(P>0.05). Panelist detected no differences in sensory characteristics between treatments. Results

suggest that the two novel antimicrobial interventions would be acceptable to use on beef subprimals

subjected to blade tenderization without detrimental effects.

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EFFECTS OF ANTIMICROBIALS ON SHELF-LIFE CHARACTERISTICS OF

GROUND BEEF


S.E. Belanger, A.M. Stelzleni

UNIVERSITY OF GEORGIA,

ATHENS, GEORGIA

The objective of this research was to evaluate pathogen interventions on ground beef quality

characteristics. Beef trim (85/15) from whole boneless chuck rolls was treated with 4.5% lactic acid (LA),

200 ppm peroxyacetic acid (PAA), 50 ppm electrolyzed oxidizing water (EO), 2.0% levulinic acid plus

0.2% sodium dodecyl sulfate (LVA-SDS), and untreated control (CON). Fifteen kilograms of trim per

treatment were individually placed in an automated spray cabinet for treatment application. Beef trim was

ground and 30 of the 100 patties/treatment were randomly selected and assigned to aerobic retail display

for 0, 1, 2, 3, 4, or 5 d. An additional 5 patties were individually vacuum packaged and frozen for Kramer

shear force analysis (replicated 3 times). On their respective day patties were collected for psychotropic

bacteria, pH, purge, and lipid oxidation analysis. Objective and subjective color was measured daily on d

5 patties. After d 5 of display LA inhibited the growth of psychotropic bacteria compared to all other

treatments (P<0.05). After d 1 of shelf life PAA lipid oxidation was lower than EO and LA (P<0.05). PAA

retained greater redness after d 5 compared to all other treatments (P<0.05). After d 2 of display the

discoloration of LA and LVA-SDS maintained a lighter color compared to all other treatments (P<0.05).

After d 4, CON, LA, and LVA-SDS had a lower percent discoloration compared to other treatments

(P<0.05). Kramer shear was similar for all treatments (P>0.05). The use of EO and LVA-SDS would

maintain acceptable color for ground beef.

GASEOUS ANTIMICROBIALS FOR PRODUCE AND LOW-MOISTURE FOOD:

EQUIPMENT DEVELOPMENT, SENSORY EVALUATION, MODELING, AND

REGULATORY COMPLIANCE

CHEN-AN HWANG (Project Director)

Hwang, C.; Huang, L., Fan, X.

AGRICULTURAL RESEARCH SERVICE WYNDMOOR, PENNSYLVANIA

Produce and low-moisture foods (LMF) are frequently linked to foodborne illnesses caused by bacterial, protozoan, and viral pathogens. Gaseous forms of chlorine dioxide and ozone are advantageous than

the aqueous forms for treating produce and LMF. The objective of this project is to determine the sensory and nutritional quality of selected produce and LMF treated with gaseous chlorine dioxide and ozone and

40

to develop commercial equipment for large-scale applications. It is necessary to search and identify the optimal processing parameters for producing safe products in large scale while maintaining sensory

qualities and meeting the performance standard as required by the regulatory agency. This study will attempt to search for optimal processing parameters (gas concentration, temperature, humidity, and time) for prcessing produce and LMF, and then evaluate the sensory (odor, color, and texture) and nutritional

(e.g., ascorbi acid, lycopene, and antioxidants) quality of products using chemical analyses and instruments. In scaled-up evaluations, existing commercial equipment such as spray washing tunnels for produce and fluidized-bed dryers for LMF will be modified for gas applications. For products regulated by

performance standards, such as almonds requiring a 4‐log reduction of Salmonella on the surface, a process filing to FDA will be prepared. To support filing, critical process parameters that influence the

pathogen reduction will be identified, and mathematical models will be developed to simulate the reduction of foodborne pathogens. The results of this study will be useful for the food industry for adopting appropriate processes to reduce incidences of foodborne infections.

UNDERSTANDING ANTIBIOTIC RESISTANCE OCCURRENCE AND

DEVELOPMENT OF MITIGATION STRATEGIES IN CATTLE

K. CASEY JEONG (Project Director)

R. Mir and K. Casey Jeong

UNIVERSITY OF FLORIDA GAINESVILLE, FLORIDA

The effectiveness of antibiotics has been challenged by the occurrence of dangerous infections that

antibiotics can no longer treat, as pathogens are developing resistance to the drugs. Despite its negative and growing impact on not only public health, but also animal health, there are few effective strategies for reducing the prevalence of antimicrobial resistant microorganisms (ARMs) in farm animals. There is thus

a compelling need to develop mitigation strategies for ARMs in food animals. Development of rational mitigation strategies requires a comprehensive understanding of when, where, and how resistance was acquired, and how resistance genes and ARMs move among animals. However, little data is available on

factors contributing to the acquisition of ARMs in agricultural systems. On the basis of our findings, our central hypothesis is that current management practices for grass-fed cattle create conditions conducive to the acquisition and development of antibiotic resistance in the gastrointestinal tract. Therefore,

understanding of AR occurrence from earlier in the food animal production cycle is essential to develop mitigation strategies. This integrated research and extension project focuses on identifying associated risk factors and origin for the presence of such resistance in farm animals to develop methods for

reducing ARMs in farm animals. Conventional and new extension approaches will be used to better educate stakeholders and the public to reduce ARMs in cattle, enhancing the sustainability of US agriculture and global food safety and security.

41

MODELING DRY CROSS-CONTAMINATION OF SALMONELLA DURING

ALMOND PROCESSING

SANGHYUP JEONG (Project Director)

MICHIGAN STATE UNIVERSITY

EAST LANSING, MICHIGAN

The overall goal is to reduce the risk of salmonellosis associated with low-moisture foods by elucidating

the physical mechanism of cross-contamination during nut processing. The specific objectives were to develop a first-principle based discrete element model of bacterial transfer, and to quantify the effect of

physical and environmental factors as model parameters on the transfer of Salmonella within bulk almonds.

A Discrete Element Modeling (DEM) software (LIGGGHTS: LAMMPS Improved for General Granular and Granular Heat Transfer Simulations) was utilized to simulate a small batch of almonds in a rotating drum

with inoculated almonds in a low-water activity environment to assess the modeling methodology. To calibrate/validate the model, almond kernels and inoculated almonds were conditioned at various water activities, placed in a stainless-steel drum, and rotated for various combinations of durations and

rotational speeds in a controlled environment. The DEM model with granular physics coupled with electrostatic components yielded RMSE = 0.108 (Log CFU/g), which is very accurate representation of the phenomena. The actual bacterial transfer rates increased (P < 0.05) as water activity or the total

number of revolutions increased. However, the rotational speed did not affect (P > 0.05) transfer rates. Environmental factors, such as water activity, appear to be crit ical factors affecting bacterial transfer in low-moisture products. A subsequent secondary model as a function of water activity will significantly

increase the accuracy of the first-principle-based discrete element model, which will lead to a better understanding of the bacterial dry transfer mechanism during nut processing.

EFFECT OF SURFACE PROPERTIES ON COLLOID AND BACTERIAL

RETENTION ON NATURAL AND SURROGATE PRODUCE SURFACES

YAN JIN (Project Director)

Taozhu Sun, Volha Lazouskaya, Gang Wang, and Yan Jin

UNIVERSITY OF DELAWARE, NEWARK, DELAWARE

Bacterial contamination of fresh produce is a growing concern in food industry. Pathogenic bacteria can attach to and colonize the surfaces of fresh produce and cause decease outbreaks among consumers.

Surface properties of bacteria and produce can affect bacterial contamination; however, effects of produce hydrophobicity, topography, and roughness on bacterial retention are still not well understood. At first, we used spherical colloids as bacterial surrogates to investigate colloid retention on fresh produce

surfaces including tomato, orange, apple, lettuce, spinach, and cantaloupe, and on micro-patterned polymer surface SharkletTM. Colloid retention and rinsing from produce surfaces was investigated in batch experiments, and all investigated surfaces were characterized in terms of surface roughness and

hydrophobicity. Surface topography and roughness were confirmed to be important parameters in colloid

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retention on produce, but the data showed high variability among natural produce samples. Therefore, we developed methods of making produce replicas of spinach, lettuce, orange, and tomato using polymeric

materials. Polymeric produce replicas have lower chemical and topographical variability among samples, but still preserve representative surface roughness and topography features. Comparison of colloid retention and removal from fresh spinach and spinach replicas demonstrated good agreement, and

further experiments with produce replicas were conducted with bacteria. Our data improve understanding of how surface roughness and topography features affect bacterial retention on fresh produce, and will contribute to better produce handling practices.

SURFACE ROUGHNESS OF FRESH PRODUCE INVESTIGATED WITH

CONFOCAL MICROSCOPY AND WHITE LIGHT INTERFEROMETERY

YAN JIN (Project Director)

Volha Lazouskaya, Taozhu Sun, Gang Wang, and Yan Jin

UNIVERSITY OF DELAWARE, NEWARK, DELAWARE

TiO2 nanoparticles can generate strong photocatalytic activity under UV-A light, which can degrade organic molecules for cleaning and disinfection purposes. However, research is lacking in applying TiO2

for foodborne viruses disinfection. Among foodborne outbreaks, human norovirus (HuNoV) and hepatitis -A virus (HAV) are two major concerns since they are very resistant to disinfection. In this study, murine norovirus (MNV-1) was used as a surrogate for HuNoV which is non-culturable. A polyurethane binder

was used to mix with TiO2 powder in order to attain a stable coating on indented stainless steel surfaces. Viral titers were determined by plaque assay and RT-PCR before and after treatment. 300 uL of purified MNV-1 or HAV with titers of 8.68 log (PFU/mL) or 5.52 log (PFU/mL), respectively, were inoculated onto

each coupon. 5.53 log PFU/coupon and 0.52 log gc/coupon MNV-1 reductions could be achieved with TiO2 coated surfaces with a 8100 mJ/cm2 UV-A dose, while 4.2 log PFU/ coupon and 0.54 log gc/ coupon HAV reductions were achieved with a 13500 mJ/cm2 UV-A dose. However, without TiO2 or

without UV-A, little reductions in virus infectivity were achieved. Similar results were achieved by methylene blue photocatalytic decay rate experiments, which showed that TiO2 coated surfaces had much higher photocatalytic activities than binder-coated or plain stainless steel surfaces alone. Thus TiO2

is an effective disinfectant of foodborne viruses when activated by UV-A, but long exposure times are required. With further development, photocatalytic disinfection with TiO2, could be applied to equipment used in food processing to prevent cross-contamination by foodborne viruses.

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FACTORS THAT INFLUENCE SALMONELLA COLONIZATION OF PLANTS

JEFFREY JONES (Project Director)

Potnis, Cowles, Jones and Barak

UNIVERSITY OF FLORIDA

GAINESVILLE, FLORIDA

Plant disease is an important factor influencing the ability of Salmonella enterica to survive on plants after

contamination. We recently discovered that bacterial spot xanthomonads influence the fate of S. enterica

on the leaves of tomato. Virulent X. perforans modifies phyllosphere environment, which in turn increases

persistence of S. enterica on infected leaves. In contrast, avirulent X. perforans initiates effector-triggered

immunity and thus, activates plant defenses which result in reduced survival of S. enterica. We further

dissected the mechanism of S. enterica survival and proliferation on Xanthomonas-infected leaves using

four diverse bacterial spot Xanthomonas species. S. enterica can grow and proliferate forming large

aggregates in association with watersoaked and subsequent necrotic leaf tissue following infection by X.

euvesicatoria and X. gardneri. On the other hand, X. vesicatoria, which causes the least severe necrosis

under tested conditions did not support overall growth of S. enterica, similar to healthy leaves. Our results

indicate that pathogen-induced watersoaking and necrosis enable S. enterica access to the leaf interior

and proliferate. Understanding the mechanism of proliferation of human pathogen is of significance in the

epidemiology of food borne illnesses and in managing these outbreaks. Our research suggests that

managing plant diseases in tomato fields can significantly help mitigate pre-harvest contamination by S.

enterica.

NANOSCALE PATTERNINGS ON STAINLESS STEEL SURFACES FOR

PREVENTION OF BACTERIAL ADHESION

SOOJIN JUN (Project Director)

Natthakan Rungraeng, Yong Li, Chang-Hwan Choi, and Soojin Jun

UNIVERSITY OF HAWAII

HONOLULU, HAWAII

The bacterial adhesion mechanism is considerably complex and many factors can affect adhesion

scenarios. Although many techniques have been tried to minimize the surface contamination resulting

from bacterial adhesion, the effect of nanoscale surface patterns with modulated surface wettability to the

bacterial adhesion was still under investigation. Cell adhesion in vivo is a three-dimensional (3D)

phenomenon that is distinct from the interaction on two-dimensional (2D) surfaces in vitro. The

attachment of bacterial cells is associated with various cell-surface interactions including hydrodynamic

force, porosity, surface energy, and roughness. Recent advancements in fabrication have made it

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possible to create well-organized nanofeatures (i.e. nanoporous and nanopillared) uniformly over a large

surface area of a metal specimen. However, it has not yet been studied systematically how such well-

regulated nanofeatures affect the adhesion of bacteria and the formation of biofilms in various surface

wetting conditions. Nanosmooth (control) and nanoporous stainless steel surfaces were fabricated by

anodizing the degreased specimen in a 5% vol. of perchloric acid in anhydrous ethylene glycol. The

applied voltage and anodization time were varied to obtain different pore diameters. The presences of 50

and 80 nm nanoporous patterns significantly inhibited the adhesion of L. monocytogenes by 2.0 to 2.3

log-cycles, depending on the pore diameter. However, an increase in the pore diameter from 50 to 80 nm

did not significantly increase the anti-adhesion effect of the nanoporous surface; hence, the 50 nm pore

size which required less power consumption and time to fabricate (40V 10 min) was preferable .

PHYSIOCHEMICAL CHARACTERIZATION OF MICROWAVE-ASSISTED

SYNTHESIS OF SILVER NANOPARTICLES SYNTHESIZE USING ALOE VERA

(Aloe Barbadensis)

LAMIN KASSAMA (Project Director)

Lamin S. Kassama, John A. Kuponiyi, Tatiana Kukhtareva

ALABAMA A & M UNIVERSITY

NORMAL, ALABAMA

Biosynthesis production of silver nanoparticles (AgNP) using different biological extracts is gaining recognition due to its numerous applications. Although, different approaches (physical and chemical) have

been used for the synthesis of AgNP, the green chemistry method is most preferable because of its high production rate, environmentally benign and cost effective. Aloe Vera (AV) contain a chemical compounds such as “Antraquinones” that are known for antibacterial, antivirus and anticancer properties and its extract

is a good chemical reduction agent of AgNP. Hence, it was hypothesized that microwave assisted synthesis will produce highly concentrated, more stable and biologically active AgNP’s. Thus, the objective of the study is to evaluate the effect of microwave assisted synthesis on the reaction kinetics and concentration

of AgNP’s. Factorial experimental design was used with three different factors, 1) Extraction solvent (water & ethanol), 2) Heating methods (microwave & conventional heat), and 3) pH (7, 8, 9, 10). Extracts with water and ethanol base from AV skin was used as the reduction agent for the synthesis of AgNP. The

biological extract and AgNO3 were blended and heated to synthesize AgNP’s. The reaction process was monitored using UV-Visible spectroscopy. Fourier Transfer Infrared spectroscopy (FTIR) was used for the characterization of biological compounds and their substituent. Dynamic Light scattering (DLS) method was

used to characterize particle size of AgNP and their bio-molecular stability. The combine treatment of microwave with ethanol and pH (10) yielded significant (p < 0.05) higher concentration (20.4 ppm) of AgNP and a corresponding average particle size of 80 nm. Microwave synthesizes also showed significantly (p <

0.05) higher concentration of biological compounds such as aliphatic amines, alkenes (=C-H), alkanes (C-H), alcohol (O-H) and unsaturated esters(C-O). Improved AgNP have potential applications as antimicrobial additive to polymers used for developing smart food packaging.

Keywords: Microwave, FTIR, Aloe Vera, Nanoparticles, Dynamic Light scattering

45

AN ASSESSMENT OF FOOD SAFETY PRACTICES AT FARMERS MARKETS

IN KENTUCKY

JOHN KHOURYIEH (Project Director)

WEST KENTUCKY UNIVERSITY BOWLING GREEN, KENTUCKY

Increased consumption of locally produced food along with outbreaks of food related illnesses has

caused concern regarding the safety of food grown for direct to consumer marketing. The project

objective is to enhance farmers’ knowledge of safe production and handling of fresh produce, reducing

the risk of contamination of foodborne pathogens by implementation of good agriculture practices (GAPs).

Through the use of surveys administered to producers at farmers’ markets in Kentucky, the study

identified demographic information, and assessed producers’ knowledge of GAPs, microbial

contamination, as well as current practices and perceived barriers which may prevent implementation of a

food safety program. Of the 160 farmers' who participated in the survey, 90% indicated familiarity with

GAPs, though less than 50% indicated water, ice, harvest equipment, refrigeration, storage, or transport

containers could be a potential contamination source. Only 39% of respondents indicated soil and 42%

inadequately composted manure as potential on-farm contamination sources. About 83% of respondents

indicated worker clothing and hands could be a source of contamination and 76% indicate that produce

may become contaminated in storage, while on display or during preparation at the market. Cost (71%)

was the major obstacle preventing implementation of GAPs, while not enough time was the second

largest obstacle at 68%. More than 85% of respondents indicated they are interested in training

opportunities to enhance their knowledge of GAPs. Results support the need for development of

educational materials and practical training for small-scale producers.

DIELECTRIC PROPERTIES OF BROCCOLI POWEDER AND ITS

TEMPERATURE PROFILE DURING RADIO FREQUENCY HEATING

FANBIN KONG (Project Director)

UNIVERSITY OF GEORGIA,

ATHENS, GEORGIA

Recently, Salmonella contamination was identified in low moisture foods including dried vegetable

powder. The Radio Frequency (RF) heating has a potential to be used as an alternative pasteurization

method with short heating time.

Dielectric properties of broccoli powder with 6.9, 9.1, 12.2, and 14.9% moisture content (w.b.) were

determined using a precision LCR meter and liquid test fixture over a temperature range (20-80°C), and

46

frequency (1 to 30 MHz). The RF heating rate in the broccoli powder was evaluated using a 27.12 MHz,

6kW RF oven.

The results showed that permitivitities of broccoli powder were influenced by moisture content and

temperature of sample, and frequency. Both increased with increasing moisture content and temperature,

but decreased with increasing frequency. The relationship between moisture content, temperature and

dielectric permittivities of broccoli powder at 13.56 and 27.12 MHz could be described by quadratic

models with high correlation coefficients (R2 > 0.96). The RF heating rate increased linearly with dielectric

loss factor, moisture content and compact density. The information provided in this study is useful to

develop an effective RF heating strategy to pasteurize dried vegetable powder.

GOALS AND IMPACTS OF THE A4161 PROGRAM: PREVENTION AND

CONTROL OF POULTRY FLOCKS AND POULTRY PRODUCTS, INCLUDING

EGGS

BIBIANA LAW (Project Director)

Bibiana Law; Qijing Zhang, Sandria Godwin, Hosni Hassan

UNIVERSITY OF ARIZONA TUCSON, ARIZONA

An overview of the goals and significant impacts to date from the four funded projects of the AFRI “Prevention and Control of Poultry Flocks and Poultry Products, Including Eggs” program will be

presented. This program funded $10M in total, beginning in the summer of 2012, for the implementation of integrated proposals addressing at least two of the three components: research, education and extension. Projects were to generate information and/or strategies critical to the reduction of

Campylobacter and Salmonella in poultry and poultry products. The four projects were 1) Dr. Law’s “The development of an efficacious vaccine to reduce Campylobacter in chickens”, 2) Dr. Zhang’s “Novel and practical approaches for mitigation of Campylobacter in poultry”, 3) Dr. Hassan’s “Development of novel

Salmonella control practices and integrated education program to reduce salmonellosis”, and 4) Dr. Godwin’s "Development and evaluation of science-based messages to improve consumers' storage, handling, and preparation of poultry and poultry products." The goals and significant impacts of each project will be discussed.

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NOROVIRUS TRANSMISSION DURING PRODUCE HARVEST AND PACKING:

A QUANTITATIVE MICROBIAL RISK ASSESSMENT MODEL APPROACH

JUAN LEON (Project Director)

Kira Newman, Lee-Ann Jaykus, Juan S. Leon

EMORY UNIVERSITY

ATLANTA, GEORGIA

Introduction: Norovirus (NoV) is a major cause of acute gastroenteritis and responsible for 40% of all

produce-associated foodborne disease outbreaks in the U.S.

Goal: Develop and apply a quantitative microbial risk assessment (QMRA) model that simulates the

likelihood and magnitude of NoV contamination of produce from infected workers during harvest and

packing.

Methods: A stochastic QMRA model was developed in R using data (derived from the literature or

experts) on key parameters related to: NoV load on worker hands, worker behavior, and transfer,

persistence, and dissemination of NoV. Scenario testing assessed the impact of hand washing, reduced

produce contact, and worker illness severity on produce contamination.

Results: Produce contamination was greatest for the first several items harvested immediately after

infected workers used the restroom, declining by over 2 log10 to approximately 20 virions/cm2 by the

10th item. Complete compliance of workers with recommended handwashing reduced contamination by

26.3% (SD=33.2%) (packers) and 20.2% (SD=23.8%) (harvesters), compared to the baseline model. A

doubling of handwashing efficacy reduced contamination by 29.9% (SD=35.2%). Contamination of

produce declined to a negligible level (10 virions/cm2) when both packers and harvesters were shedding

less than 107 NoV virions/g stool. This suggests that it might be relatively safe for workers to return after

the period of peak viral shedding has passed, as long as they adhere to rigorous hand hygiene.

Discussion: QMRA model results support guidelines that reduce acutely ill workers’ contact with produce

and encourage brief furlough and handwashing compliance to reduce the risk of NoV contamination.

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PLANT MICROBIOTA-DRIVEN FACILITATION OF THE PERSISTENCE,

GROWTH, AND INTERNALIZATION OF HUMAN PATHOGENS ON LEAFY

GREENS

JOHN LEVEAU (Project Director)

Lorena Rangel, Gitta L. Coaker, Trevor V. Suslow, and Johan H.J. Leveau

UNIVERSITY OF CALIFORNIA AT DAVIS

DAVIS, CALIFORNIA

The contamination of leafy greens with unwanted microorganisms is a concern that will benefit from novel

basic insights towards its practical prevention. Our research focuses on the association of the human

pathogen Escherichia coli O157:H7 with lettuce. We investigate how microorganisms that occur naturally

on lettuce leaves facilitate the survival of E. coli, in particular those microorganisms that produce the plant

hormone indole 3-acetic acid (IAA). We are performing experiments that assess three possible

mechanisms by which IAA impacts the lettuce-E. Coli association: 1) it renders E. coli more resistant to

the stresses that characterize the pre- and post-harvest environment, 2) it causes leakage of plant

nutrients that E. coli can use for growth, and 3) it stimulates stomatal opening which provides E. coli

opportunity for entry into the plant interior. The insights gained from this study will expose whether IAA is

a risk factor in the persistence of E. coli on leafy greens and whether it offers a target for future strategies

towards minimizing the potential of E. coli contamination.

RAPID CONCENTRATION/DETECTION OF FOODBORNE PATHOGENS

FROM WASH WATER FOR ENHANCED SAFETY OF FRESH FRUITS AND

VEGETABLES

DANIEL LIM (Project Director)

Elliot T. Ryser, Sonia M. Castillo, Elizabeth A. Kearns, and Daniel V. Lim

UNIVERSITY OF SOUTH FLORIDA

TAMPA, FLORIDA

This project investigates use of a novel dead-end ultrafiltration (DEUF) sampling method combined with

qPCR detection to monitor for foodborne pathogens in ≥40 l of produce wash water. Concentrated

processed lettuce wash samples will be compared to standard methods to determine if DEUF

concentration offers improved detection of test pathogens in processed lettuce. The objectives of this

49

research are to 1) evaluate physical (e.g., pH, temperature) and chemical (e.g., enzymes, EDTA,

surfactants) treatments of leafy green wash water that might degrade plant cell wall structures and reduce

filter fouling, permitting faster filtration of larger volumes, 2) compare the DEUF method with the standard

FDA BAM sampling method to detect E. coli O157:H7 and L. monocytogenes in flume water during

production of fresh-cut iceberg lettuce at MSU’s fresh-cut leafy green pilot-scale production facility, and 3)

assess the efficacy of the DEUF method to detect the two pathogens in flume and centrifugation waters at

a commercial-scale leafy green processing test facility. Initial Objective 1 studies used 100 ml batches of

sieved 5% organic load lettuce (w/v; blended lettuce solids) wash waters treated with 0.5% Tween 80 at

pH from 5-7 and incubation at 4 or 40°C. Samples were filtered through a 0.45 µm membrane to

determine filtration rates. The best improvement in filterability (1.4X the control) was observed in samples

treated with 0.5% Tween 80 at pH 7 incubated at 40°C for 30 min. Additional studies will be conducted

over the next year and are independent from Objectives 2 and 3 research.

ENHANCING LOW-MOISTURE FOOD SAFETY BY IMPROVING

DEVELOPMENT AND IMPLEMENTATION OF PASTEURIZATION

TECHNOLOGIES

BRADLEY MARKS (Project Director)

B. Marks, J. Tang, H. Thippareddi, E. Grasso, D. Gray, M. Zhu, J. Subbiah, E.

Ryser, S. Jeong, N. Anders

MICHIGAN STATE UNIVERSITY

EAST LANSING, MICHIGAN

Recent outbreaks/recalls due to Salmonella in low-moisture foods, and pending FSMA Preventive

Controls rules, make processing interventions an imperative to ensure product safety. Although various

technologies exist, they have achieved very limited market penetration, and none will provide a

universally acceptable solution. Also, “legacy” technologies not designed as “kill steps” (e.g., drying or

baking) now must be validated for this purpose.

The overall goal is to enhance development, improvement, and commercial adoption of pasteurization

technologies for low-moisture foods. Objectives are to: (1) Develop standardized validation protocols for

low-moisture food pasteurization; (2) Conduct an extensive battery of inoculated challenge studies wit h

multiple pathogen-reduction technologies; (3) Develop improvements of existing thermal processes for

enhanced food safety; (4) Develop and implement multiple outreach resources (technology comparison

tool, workshops, webinars, and a “Validation Center” for long-term industry support via validations and

training); and (5) Develop online graduate modules in low-moisture food safety, technologies, and

validation.

Research activities include inoculated challenge studies in three Biosafety Level-2(3) pilot plants for

evaluation of technologies and testing of validation protocols. Multiple workshops, webinars, and unique

curricula development will specifically target professionals in the area of low-moisture foods. Cross-

institutional and cross-disciplinary graduate learning modules will fill a gap related to low-moisture food

safety and technologies.

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Research, outreach, and education activities are highly integrated, outcomes-focused, stakeholder-

engaged (including an Industry Advisory Group), and subject to systematic assessment processes. As a

result, technology companies, processors, and regulators will be better equipped to evaluate, implement,

and validate low-moisture food pasteurization processes.

EVALUATING THE EFFECTIVENESS OF FOOD SAFETY TRAININGS BY

DETERMINING FACTORS THAT INFLUENCE GROWER ADOPTION OF

FOOD SAFETY CERTIFICATION

SHIRLEY MICALLEF (Project Director)

D. Pahl, T. Chfadi, C. Narrod, C. Walsh, D. Martin, S. Micallef

UNIVERSITY OF MARYLAND

COLLEGE PARK, MARYLAND

Introduction: Fresh produce growers are under increased pressure to abide by federal food safety

guidelines and obtain third-party Good Agricultural Practices (GAPs) certifications. Food safety trainings

have been offered in Maryland for several years, although only about one quarter of attendees implement

food safety plans and receive GAP certification.

Purpose: To increase the number of trainees implementing recommended practices, this study aimed to

define the factors influencing grower’s opinions of food safety practices and their reluctance to obtain

GAP certification.

Methods: Attendees filled out a pre-training questionnaire at full-day food safety trainings to capture their

perceptions of food safety regulations and abilities to implement recommended practices. A second

questionnaire was given post-training to self-assess skill level, training satisfaction and estimated barriers

to certification. A multiple-choice factual test on training content was given pre- and post-training to

provide a quantifiable measurement of learning. Nine months post-training, attendees were sent a follow-

up questionnaire to measure implementation of food safety practices on their farms.

Results: Over 62 participants completed the questionnaires and factual tests. Participants were involved

in a range of markets (retail to wholesale), and 80% (45/56) had never attended a previous GAP training.

After the trainings, 76% (47/61) of participants planned on implementing GAPs and receiving a

certification. Perceived difficulties to receiving certification were listed as: “none” (58%), “paperwork”

(16%), “labor” (8%), “not enough time” (5%), “ lack of infrastructure” (3%), “lack of equipment” (2%), and

“no incentive” (2%). An analysis of factual tests demonstrated improved comprehension of food safety

concepts (7.3% scored 75% or higher on pre-test, 50.9% scored 75% or higher on post-test).

Significance: These results will allow trainers to address barriers to certification and increase grower

adoption of food safety practices and documentation. These results and evaluations will be incorporated

into alternative training methods in 2015.

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DYNAMICS OF THE MICROBIOME AND RESISTOME IN BEEF PRODUCTION

SYSTEMS

PAUL MORLEY (Project Director)

Noyes NR, Xiang Y, Linke LM, Magnuson RJ, Yang H, Dettenwanger A, Abdo Z,

Jones K, Boucher C, Belk KE, Morley PS

COLORADO STATE UNIVERSITY

FORT COLLINS, COLORADO

A complex ecology modulates the dynamics of antimicrobial resistance (AMR) within food production

systems. Shotgun metagenomics can revolutionize research regarding AMR by providing access to all

bacterial taxa and antimicrobial resistance determinants (ARDs). The goal of this project was to compare

the microbiome and resistome of beef production environments from feedlot entry through slaughter.

Pens of cattle were prospectively sampled in the feedlot and slaughter systems. Metagenomic DNA was

sequenced and reads were aligned to an ARD database and classified taxonomically. Richness and

diversity were compared as were clustering and changes in relative abundance of ARDs and microbial

taxa. We identified 319 unique ARDs, comprising 14 classes and 42 mechanisms of resistance. We

identified 1,821 bacterial species in 763 genera. Microbial diversity decreased from feedlot through

slaughter and fabrication, and no ARDs were identified in post-slaughter samples. Samples clustered by

matrix and sampling location. Results portray a diverse and complex microbial ecology, with significant

changes in microbiome and resistome composition during beef production. Changes in diversity indicate

that standard harvest interventions can apply pressure to microbial populations decreasing the public

health risk for AMR transmitted through beef products.

SHIGA-TOXIGENIC ESCHERICHIA COLI (STEC) IN THE BEEF CHAIN:

ASSESSING AND MITIGATING THE RISK BY TRANSLATIONAL SCIENCE,

EDUCATION AND OUTREACH

RODNEY MOXLEY (Project Director)

COLORADO STATE UNIVERSITY

FORT COLLINS, COLORADO

This USDA-NIFA funded Coordinated Agricultural Project (CAP) involves a collaboration of 52 scientific

investigators among 16 different universities and institutions, and includes a large, diverse stakeholder

advisory board. The long-term goal of the STEC CAP is to reduce the occurrence and public health risks

from STEC O26, O45, O103, O111, O121, O145 and O157 (STEC-7) in beef using a quantitative

microbial risk assessment platform. The supporting objectives of the STEC CAP address: 1) STEC-7

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detection- reagents, sampling plan, assays, technology, partners; 2) STEC-7 microbiology, eco-

epidemiology, exposure risk, and identification of intervention targets; 3) interventions for STEC-7 risk

reduction-value, feasibility, cost-benefit, and impacts; 4) risk analysis and risk assessment; and 5) risk

management and risk communication. A progress update on each of these objectives will be reported.

OXIDATIVE STRESS RESPONSE OF BACTERIA TO SANITIZERS

NITIN NITIN (Project Director)

Phuong Le, Andrea Cossu, Glenn Young, Anupama Ranganathan, Nitin Nitin

UNIVERSITY OF CALIFORNIA

DAVIS, CALIFORNIA

One of the key scientific challenges for developing optimized washing procedures is the lack of

understanding about the response of microbes to sanitizers in complex environments with significant

organic content. The key objective of this sub-project is to develop a biosensor for optimizing selection of

sanitizers and their concentration in wash water. In this direction of research, we plan to address the

following key questions:

(a) What is the correlation between oxidative stress in microbes (measured using a biosensor) and

reduction in microbial load?

(b) What is the role microbial physiology, differences among pathogens and organic content in influencing

the oxidative stress response of microbes?

The results will compare the oxidative damage induced by diverse sanitizers and also indicate the various

biosensing approaches that are being developing for measuring the oxidative stress in microbes. Overall,

this project will provide a novel approach to determine the optimal sanitizer concentration for diversity of

fresh produce wash operations.

NANOPHOTONIC DETECTION OF PATHOGENS IN FOOD

NITIN NITIN (Project Director)

S. Lakshmanan, A. Ranganathan, N. Nitin, I.M. Kennedy

UNIVERSITY OF CALIFORNIA

DAVIS, CALIFORNIA

Photonics permit the manipulation of light with nanostructure surfaces. A fluorophore label that i s located

in the vicinity of a resonance in a leaky wave guide structure will experience an enhanced emission of

fluorescence. We use this principle to detect pathogens in food using two methods: direct detection of

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bacterial DNA at very low levels; and the detection of lytic bacteriophages that specifically infect target

pathogenic bacteria, reproduce and are released. The latter method is used to detect only viable bacteria.

Very low levels of detection are possible with both methods, demonstrated using model systems such as

the T7 phage that infects E. coli.

BACTERIOPHAGE-BASED NANOPROBES FOR RAPID BACTERIA

SEPARATION

SAM NUGEN (Project Director)

Juhong Chen, Bradley Duncan, Li-Sheng Wang, Vincent M. Rotello and Sam R.

Nugen

UNIVERSITY OF MASSACHUSETTS

AMHERST, MASSACHUSETTS

The lack of practical methods for bacterial separation remains a hindrance for the low-cost and successful development of rapid detection methods from complex samples. Antibody-tagged magnetic particles are

commonly used to pull analytes from a liquid sample. While this method is well -established, improvements in capture efficiencies would result in an increase of the overall detection assay performance. Bacteriophages represent a low-cost and more consistent biorecognition element as

compared to antibodies. We have developed nanoscale bacteriophage-tagged magnetic probes, where T7 bacteriophages were bound to magnetic nanoparticles. The nanoprobe allowed the specific recognition and attachment to E. coli cells. The phage magnetic nanprobes were directly compared to

antibody-conjugated magnetic nanoprobes. The capture efficiencies of bacteriophages and antibodies on nanoparticles for the separation of E. coli K12 at varying concentrations were determined. The results indicated a similar bacteria capture efficiency between the two nanoprobes.

EXAMINING THE DYNAMICS OF NANOPARTICLES IN PLANTS

SANJAI PARIKH (Project Director)

Devin Rippner, Ryan Davis, Matt Dumlao, Julie Sutcliffe, Andrew McElrone,

Peter Green, Wendy Silk

UNIVERSITY OF CALIFORNIA AT DAVIS

DAVIS, CALIFORNIA

Copper oxide and iron oxide nanoparticles (CuO NPs and Fe2O3 NPs) were used as model NPs to

investigate NP dynamics in duckweed (L. [Spirodela] punctate), lettuce, and carrots. The size and surface

charge of CuO NPs and Fe2O3 NPs were characterized by transmission electron microscopy (TEM),

electrophoretic mobility, and dynamic light scattering (DLS). The toxicity of different sizes of CuO to

duckweed was investigated using 23 nm CuO NPs, 50 nm CuO NPs, 2000 nm CuO microparticles (MPs),

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and aqueous CuCl2. Root hydraulic conductivity inhibition experiments on lettuce and carrots were

conducted using 50 nm CuO NPs, 2000 nm CuO MPs, and aqueous CuCl2. Plant uptake of radio labeled

Fe2O3 NPs for all three species was visualized by autoradiography. Results from the toxicity study show

increased toxicity as CuO size decreased. Similarly, root hydraulic conductivity was shown to decrease in

the presence of CuO NPs compared to CuO MPs. Based images from auto radiography, intact Fe2O3

NPs were shown to accumulate in the roots and nodes of all three species. Future studies will investigate

the role of naturally occurring organic ligands on CuO NP toxicity to duckweed and on CuO NP and

Fe2O3 NP transport in crops and soils.

APPLICATION OF LOW WAVE-LENGTH UV-C IRRADIATION FOR TREATING

MYCOTOXINS IN TURBID FLUIDS

ANKIT PATRAS (Project Director)

Ankit Patras, Sharath Chandra, Bharat Pokharel



Introduction: Patulin, a mycotoxin produced by several genera of fungi, including Aspergillus and

Penicillium, has been an important concern in apple-based products due to its toxicity. Ultraviolet (UV)

irradiation is a sterilization method effective against a range of bacteria and viruses while being non-

thermal and non-adulterating in its mechanism of action. This makes UV irradiation a unique and

attractive method to control mycotoxins in fluids.

Purpose: The objective of this study was to evaluate the effect of UV irradiation in combination with a

photosensitizer (ATZ1) on patulin stability.

Methods: Experiments were conducted using a collimated beam system operating at 254 nm wavelength.

Appropriate fluence correction factors were accounted when quantifying the UV dose. Chemical profiling

was conducted using HPLC. Kinetic modeling supplemented with two-way ANOVA was performed at 5

percent significance level to assess the effectiveness of UV irradiation along with the application of

photosensitizer on patulin stability.

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QUANTITATIVE RISK ASSESSMENT OF TAXOPLASMA GONDII INFECTION

THROUGH CONSUMPTION OF FRESH PORK IN THE UNITED STATES

ABANI PRADHAN (Project Director)

Miao Guo, Robert L. Buchanan, Jitender P. Dubey, Dolores E. Hill, H. Ray

Gamble, Jeffrey L. Jones, and Abani K.

UNIVERSITY OF MARYLAND

COLLEGE PARK, MARYLAND

Toxoplasma gondii is one of the leading foodborne pathogens in the U.S. The Centers for Disease

Control and Prevention reported that T. gondii is one of three pathogens, which together account for

>70% of all deaths due to foodborne illness in the U.S. Consumption of undercooked pork products in

which T. gondii has encysted is a common transmission route for human infection. The goal of this study

was to develop a farm-to-table quantitative microbial risk assessment (QMRA) model to predict public

health burden through consumption of fresh pork in the U.S. T. gondii prevalence in pigs was described

by a weighed prevalence and bradyzoites concentration was calculated in each pork cut of an infected

pig. A logistic regression and a log-linear regression were developed to model the reduction of T. gondii

during moisture enhancement and home cooking, respectively. An exponential dose-response model was

developed. The mean probability of infection per serving of fresh pork products ranges from 4.8× 10^-6 to

1.41× 10 -̂4, corresponding to 98,267 new infections annually in general population. Approximately 745

new infections occurred each year in pregnant women, which associated with 216 congenital

toxoplasmosis cases. Sensitivity analysis suggested that cooking is the most important parameter

impacting human health risk. This study addressed the disease burden of T. gondii infection and

quantified the effects of processing on the viability of cysts, which provides the scientific basis for risk

management and also could serve as the baseline model for the QMRA of T. gondii in other meats.

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IDENTIFICATION AND MANAGEMENT OF CRITICAL CONTROL POINTS FOR

LIMITING THE SPREAD OF ANTIBIOTIC RESISTANCE FROM AMNURE TO

FRESH PRODUCE

AMY PRUDEN (Project Director)

Amy Pruden, Katharine Knowlton, Partha Ray, Monica Ponder, Giselle Guron,

Kang Xia, Cully Hession, Leigh-Anne Krometis, Thomas Archibald, Amber

Vallotton.

VIRGINIA TECHNOLOGY

BLACKSBURG, VIRGINIA

There is growing evidence and concern that agricultural practices, including antibiotic use and manure

management, are contributing to the growing antibiotic resistance problem in humans. Simultaneously,

there is growing demand for fresh produce, which may carry antibiotic resistant bacteria (ARBs) and

antibiotic resistance genes (ARGs) of manure origin. This new integrated research, education, and

extension program seeks to act proactively by focusing on critical control points that may prevent the

spread of antibiotic resistance from farm to fork, including: 1) antibiotic use; 2) manure composting; 3) soil

selection; 4) crop selection; and 5) fresh produce post-harvest processing practices. A novel and

practical outcome of this project will be examination of whether the proposed FDA FSMA rules for

composting manure, which are intended for control of pathogens, will effectively limit the spread of ARGs.

Research will focus on tracking the fate of antibiotics, ARBs, and ARGs through each of these critical

control points, including lab, greenhouse, and field-scale studies. Methods include advanced analytical

chemical methods, culturing of ARBs, and high-throughput metagenomic and DNA amplicon sequencing.

Education activities include an interdisciplinary graduate education program [Agricultural Sources of

Antibiotic Resistance (AgSoAR)], hosting undergraduate practicums, and developing and implementing

course modules. The extension effort will serve to translate research into practice, using vehicles such as

websites, publications, webinars, trainings, and workshops in order to reach a wide array of stakeholders,

including producers, consumers, veterinarians, and policy-makers.

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INFECTION OF PIGS WITH SALMONELLA AND LAWSONIA INCREASES

PUBLIC HEALTH RISK

ISAACSON RICHARDSON (Project Director)

Isaacson, R, Singer, R., Gebhart, C.

UNIVERSITY OF MINNESOTA

ST PAUL, MINNESOTA

Salmonellosis is the most common bacterial food borne il lness and current interventions have had little

effect on the prevalence of this pathogen in swine or on the incidence of disease in humans. This

probably is the result of the emergence of new strains of S. enterica and the lack of known pathogen

control points during animal production. Our preliminary data has shown that pigs co-infected with S.

enterica serovar Typhimurium and L. intracellularis shed higher levels of S. enterica and for a longer

period of time. Our hypothesis is that an L. intracellularis infection of pigs increases the risk of

salmonellosis in humans. The goals of this project are to determine the duration and quantity of S.

enterica shed by pigs co-infected with L. intracellularis and to determine if vaccination with an L.

intracellularis specific vaccine mitigates S. enterica shedding. A third goal is to quantify microbiome

changes in the intestinal tract in response to infections with these two pathogens to identify new targets

that could be exploited to reduce shedding of S. enterica. There are 3 specific aims in this project: 1) to

determine the duration and quantity of S. enterica shed by pigs infected with S. enterica or S. enterica

and L. intracellularis. 2) to determine the effect of vaccination against L. intracellularis on shedding S.

enterica, and 3) to determine intestinal microbiome changes in pigs that are singly and dually infected and

with or without vaccination.

ECONOMIC IMPACTS OF E. COLI MITIGATION

PARR ROSSON (Project Director)

Parr Rosson and Flynn Adcock

TEXAS AGRICULTURE AND MECHANICAL

COLLEGE STATION, TEXAS

There are a variety of costs and benefits associated with E. Coli and the mitigation of its impacts. Costs

of E. Coli include the those borne by meat packers and processors in terms of lost sales, recall expenses,

and the purchase of E. Coli reducing technologies. Other costs include health costs incurred by

individuals who are affected by E. Coli and lost time at work. Benefits of decreased E. Coli occurrence

include lower costs of both recalls and lost sales for industry and decreases in both health costs and lost

time at work for those consumers contracting E. Coli-related illnesses. E. coli costs the US economy

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$478 million annually. When these costs and benefits are aggregated, a set of economy-wide economic

impacts can be estimated. This poster will display these impacts using a scenario-based analysis for the

reduction of E. Coli.

RISK ASSESSMENT AND INTERVENTION STRATEGIES FOR THE

EMERGING STRATEGIES FOR THE EMERGING FOOD SAFETY THREAT OF

OCHRATOXIN IN THE UNITED

DOJIN RYU (Project Director)

Andreia Bianchini, Jack C. Cappozzo, Lauren S. Jackson, Jeffrey D. Palumbo,

Jayne E. Strat

UNIVERSITY OF IDAHO

MOSCOW, IDAHO

Ochratoxin A (OTA) is one of the important mycotoxins that contaminate a wide range of food

commodities. While OTA is considered as a possible human carcinogen, it has been known to be

nephrotoxic, hepatotoxic, immunosuppressive, mutagenic, and teratogenic. Optimization of methods for

detecting and quantifying OTA in different commodities was carried out followed by a national survey of

OTA in a total of 3,880 samples collected in the U.S. between 2012 and 2014. Sampling locations

include San Francisco (CA), Moscow (ID), Minneapolis (MN), Fargo (ND), Chicago (IL), Lincoln (NE),

Pittsburg (PA), and Dallas (TX). OTA was not detected in infant formulas (53 milk - and 45 soy-based),

milk (76), and beer (171) samples. The incidence and level of OTA were generally low in cereal grains,

meats, wine, nuts, and dried fruits, except in raisins. However, it was notable that oat -based breakfast

cereal and infant cereal samples were contaminated with OTA at levels that may be of concern. The

incidence of OTA in 662 samples of breakfast cereals, snacks, and infant cereals was 40% in the range

of 0.1- 22.1 ng/g. In particular, levels exceeding the maximum limits (processed cereal-based products 3

ng/g, nfant cereal 0.5 ng/g) for OTA by EU Regulation were detected in 46 out of 255 oat based breakfast

cereals, snacks and infant cereal samples. Given the long half-life of OTA in humans (ca. 35 days), a

quantitative risk analysis needs to be performed to estimate the exposure to this potent mycotoxin.

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FOOD SAFETY EDUCATION AND BEHAVIORAL CHANGES AMONG DEAF

AND HARD OF HEARING POPULATION: A MODEL STUDY

DOJIN RYU (Project Director)

Jessie Hunter, Karen Killinger, Renee Magnan, David Mercaldo, Gulhan Unlu,

and Dojin Ryu

UNIVERSITY OF IDAHO

MOSCOW, IDAHO

Food safety practices in private homes in the United States do not align with food safety

recommendations, even with adequate food safety knowledge, thereby putting individuals at risk for food

borne illness. The Deaf individuals are at an increased risk for lack of food safety knowledge due to

communication barriers and lack of educational approaches culturally appropriate for the Deaf culture.

Develop and assess the usability of standard survey design techniques including: paper and online

formats and two forms of Likert scale 5-point and 3-point response options with American Sign Language

among the Deaf adolescents. Cluster sampling technique recruited 28 participants, ages 16-21 years,

from four schools for the Deaf and hard of hearing in Idaho, Washington, Texas, and California. The

Food Safety Survey questionnaire was composed of 45 questions related to food safety knowledge.

Validity, reliability, and item difficulty assessments, and participant feedback were used to assess pilot

study’s ability to measure food safety constructs for this population. Survey participants’ understood the

importance of following the standard food handling practices including washing fresh fruits and

vegetables before eating or serving them (mean =1.00), believed it was important food is prepared in a

safe way (mean= 1.07) and washing hands before eating (mean=1.21). However participants were less

likely to recognize the safest method for thawing meat (mean=2.32), wash hands hand for 20 seconds or

more (mean= 2.21), and wash hands after blowing their nose (mean=2.11). The food safety words and

phrases respondents most frequently “know what word means” were bacteria (55.6%), virus (48.1%) and

food preparation (40.7%) while the least familiar were handling produce (37.0%), foodborne illness

(22.2%), and cross-contamination (22.2%). Reaching target audiences with unique communication

challenges requires development of tailored surveillance tool. These results can be applied to research in

other populations with low health literacy.

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ALTERNATIVES TO ANTIBIOTICS IN ANIMAL AGRICULTURE: IMPACTS ON

ANTIMICROBIAL RESISTANCE OF ENTERIC BACTERIA

HARVEY MORGAN SCOTT (Project Director)

Scott, HM; Boerlin, P; Drouillard, JS; Nagaraja, TG; Tokach, MD

TEXAS AGRICULTURE AND MECHANICAL UNIVERSITY


The overall goal of our project is to identify, evaluate, and implement practical and widely adoptable

interventions for managing antibiotic resistance (AR) among enteric bacteria in swine and beef cattle

production systems.

We explore the impacts (both positive and negative) of alternatives to antibiotics on the antimicrobial

resistance and microbial ecology of enteric bacteria in swine and beef cattle and seek to understand the

mechanisms of dissemination and co-selection of resistance factors as observed among the enteric

bacteria, by focusing on mobile genetic elements such as plasmids. Later, we will disseminate the

findings of our research through outreach and education efforts to assist stakeholders to assess the

relative risks and benefits of each alternative to antibiotics.

We have completed 3 out of 4 field trials to date. Initial results from the two swine studies (post -weaned

pig and grower/finisher pig) focused on metals (copper and zinc), essential oils, and beta-agonists

(ractopamine) in comparison to traditional antibiotic regimens (chlortetracycline) will be presented. We

use phenotypic (both relative and absolute quantities) concerning susceptibility to antibiotics and metals

as well as genotypic (PCR and whole-genome sequencing) outcomes in our analyses.

ANALYSIS OF THE GEOSPATIAL DISTRIBUTION OF STAPHYLOCOCCUS

AUREUS IN COMMUNITIES AND RAW MEAT PRODUCTS

TARA C SMITH (Project Director)

Tara C Smith, Dipendra Thapaliya, and Margaret Carrel

KENT UNIVERSITY

KENT, OHIO

Raw meat samples (n=3290), environmental samples (n=276) and human samples from 263 individuals

were collected over a period of one year in Johnson County, Iowa, and Keokuk County, Iowa, as part of

an ecological study examining the distribution of Staphylococcus aureus in Iowa. All isolates were spa

typed and tested for the presence of the PVL genes and mecA. Descriptive mapping indicates that the

61

distribution of genetic diversity within households and the retail environment in Johnson and Keokuk

Counties varies greatly. Spatial regression is used to link the presence of isolates with mecA and PVL

genes in meat samples to the presence of these genes in nearby household participants, and to match

spa types between samples and individuals. These analyses will allow us to determine the distribution of

shared molecular types between humans and raw meat samples in the same geographic locations,

potentially suggestive of contamination from raw meat products into the participants' homes and

communities. Additional analyses, including a formal risk assessment, are ongoing.

CONTROL OF FOOD-BORNE BACTERIAL AND VIRAL PATHOGENS USING

MICROWAVE TECHNOLOGIES

JUMING TANG (Project Director)

Juming Tang and Shyam Sablani

WASHINGTON STATE UNIVERSITY

PULLMAN, WASHINGTON

The project has the central goal of the control of either bacterial or viral foodborne illness. To accomplish

this goal, the project has several branches. One branch focuses on the study of bacterial and viral

sensitivity to thermal processing, in order to define temperature and time conditions for pasteurization. A

complementary branch of this project is aimed toward developing a small , pilot-scale microwave

pasteurization system that allows for the process development and validation studies of prepackaged

foods produced over a wide range of temperatures. Experience gained in producing this pilot -scale

system is useful for scale-up strategies aimed at production models. Use of this pilot-scale system is

being used to demonstrate this technology to food industry representatives and show its applicability

toward producing ready-to-eat meals. Computer simulation models developed from the pilot system are

now being used to estimate future capital costs and energy requirements of large-sized systems. This

data will be shared with the food industry as they develop their own large scale versions of these

machines. All of the systems produced for this project are protected under a US Patent.

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INTEGRATING IMMUNO-SEPARATION WITH FIBER OPTIC

SPECTROSCOPIC TECHNIQUES FOR QUICK DETECTING FOOD-BORNE

PATHOGENS

SHIQUAN TAO (Project Director)

Shiquan Tao (PhD), Jason C. Ray, Muhammad S. Almas, Cole A Guyer, Maya

Alex and Hemant K. Naikare (PhD)

WEST TEXAS A&M UNIVERSITY

CANYON, TEXAS

Two immune-separation fiber optic spectrometric detection methods have been developed for detecting

Salmonella in raw egg samples. The first method uses antibody-coated magnetic particles for trapping

Salmonella typhimurium bacteria from egg sample. The bacteria-trapped magnetic particles are

separated from egg sample by using a strong magnet. An enzyme-linked immunosorbent assay method

was adopted and revised for detecting the bacteria trapped onto the magnetic particles. The second

method uses an antibody-coated optical fiber as a sampling tool. A wet-chemical method has been

developed for coating anti-Salmonella antibody on surface of silica optical fibers. An optical fiber

fluorescence immunoassay method was developed for detecting bacteria trapped on optical fiber surface.

Both immune-separation methods can be used for separating bacteria from complex food sample

matrices. In this poster presentation the advantages/disadvantages and potential applications of these

two separation/detection methods in food safety inspection programs will be discussed.

ROLE OF SURFACE TOPOGRAPHY AND PHYSICO-CHEMISTRY ON

DEVELOPMENT AND APPLICATION OF NOVEL INTERVENTIONS TO

INHIBIT PAHTOGEN ATTACHMENT

MATHEW TAYLOR (Project Director)

Oh, J. K., K. Perez-Lewis, Y. Yegin, M. Zhang, L. Cisneros-Zevallos, M. Akbulut,

A. Castillo

TEXAS A&M UNIVERSITY


The primary goal of this project was to utilize fundamental and applied research to gain mechanistic

understanding of bacterial foodborne pathogen adhesion to produce and forces required to inhibit

pathogen adherence to produce. Physico-chemical analyses of experimental produce items quantified

factors with greatest contributions to pathogen attachment to produce surfaces. We observed produce

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surface roughness strongly influences bacterial attachment; three different roughness length scales were

identified, each with a differing impact on resulting pathogen attachment to the produce item. From

tomato and spinach, Staphylococcus spp. exhibited greatest antagonistic activity against Salmonella

Typhimurium and Escherichia coli O157:H7 in vitro; with respect to lettuce, Lactococcus spp. exhibited

greatest antagonistic activity against pathogens. Data suggest, though native microorganisms on produce

surface may not inhibit pathogen growth, there may be potential utility for decreasing pathogen

attachment strength. We demonstrated the essential oil component (EOC) geraniol was able to be loaded

into polymeric nano-particles (NPs) with sustainable release profile. Antimicrobial NPs inhibited S.

Typhimurium and E. coli O157:H7 growth at 0.4 and 0.2 wt.%, respectively. Geraniol-loaded NPs

displayed sustained release with a time constant of 24 hr, maintaining their anti -pathogenic properties

over a prolonged time period. Pathogens were reduced on inoculated spinach by geraniol-loaded NPs

from 0.3 to 4.2 log10 CFU/cm2. This project elaborated the biophysical forces directing attachment and

adherence of bacterial enteric pathogens to produce commodities with systematically differed surface

roughness characteristic, providing opportunity for produce decontamination, and demonstrates the

antimicrobial activity of nano-encapsulated plant-derived EOC for pathogen decontamination on post-

harvest produce.

FUNCTIONAL GENOMICS OF SALMONELLA-TOMATO INTERACTIONS AND

CROP-DRIVEN PATHOGEN LIMITATION: THE ROLE OF AGRICULTURAL

PRACTICES IN OUTCOMES

MAX TEPLITSKI (Project Director)

Teplitski, M., Marvasi, M., McClelland, M., Giovannoni, J.

UNIVERSITY OF FLORIDA

GAINESVILLE, FLORIDA

As the number and severity of produce-borne gastroenteritis outbreaks increase, we are coming to

recognize that Salmonella and other human pathogens can escape current sanitation technologies to

contaminate produce at pre- and/or post-harvest production stages. Our promoter-probe and mutant

screens define the Salmonella regulon that is involved in persistence within tomatoes. It appears that

within fruit, Salmonella relies on a complement of genes that is distinct from its animal virulence genes,

and it does not behave like a phytopathogen. We discovered that Salmonella patterns of gene expression

change in response to the tomato physiological state and genotype, and a 10-1,000-fold reduction in

susceptibility of tomatoes to human pathogens could be achieved through controlling maturity at harvest

and cultivar selection. A screen of tomato introgression lines identified already existing genotypes with at

least 100-fold reduction in susceptibility to Salmonella, as well as three lines with an increased

susceptibility to the pathogen. Tomato ethylene mutants are less conducive to Salmonella proliferation.

Manipulation of N, K fertilization and irrigation levels had minor, but measurable effects on susceptibility

of crop to Salmonella post-harvest.

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HUMAN NOROVIRUS BINDING TO LETTUCE CELL WALL COMPONENTS

AND ITS INTERNALIZATION THROUGH THE VASCULAR SYSTEM

QIUHONG WANG (Project Director)

Malak Esseili, Xiang Gao, Sarah Tegtmeier and Qiuhong Wang

OHIO STATE UNIVERSITY

WOOSTER, OHIO

Leafy greens are increasingly being associated with human norovirus (HuNoV) outbreaks. Some HuNoVs

bind to carbohydrates of histo-blood group antigens on susceptible cell surface to initiate infections. We recently discovered that HuNoV GII.4 virus-like-particles (VLPs) specifically bound to carbohydrates of lettuce cell wall materials (CWMs). Also, we showed that HuNoV surrogate, porcine sapovirus (SaV),

internalized from roots into lettuce leaves. Our objectives were to determine (i) the identity of the plant carbohydrate(s) mediating the binding to HuNoVs and (ii) the mechanisms of HuNoV transport and dissemination inside lettuce plants. Lettuce leave CWMs were extracted and fractionated before

assessing their binding to HuNoV GII.4 VLPs. In addition, mature lettuce leaves (8-week-old) were used to examine the transport of SaV through the leaf petiole. Our preliminary results showed that VLP binding to CWMs was not altered following the removal of hemicellulose and cellulose. A sequential extraction of

cell wall proteins and pectin from CWMs showed that only pectin extracted by CDTA bound to HuNoV VLPs. For the internalization assay, SaV was detected in internal tissue of lettuce at 16h with no further increase in RNA titers at 72h. An immunohistochemical staining of leaf tissue sections obtained from

SaV-inoculated and control leaves showed that SaV was detected as aggregates around the vascular bundles and in spaces between the cells, but not in control samples. Collectively, our results suggest that pectin may be the major carbohydrates in lettuce CWMs binding to VLPs of HuNoV and that lettuce

vascular system disseminates SaV inside the leaves.

NANOMATERIAL CONTAMINATION OF AGRICULTURAL CROP SPECIES

JASON WHITE (Project Director)

Jason C. White, Baoshan Xing, Lee A. Newman, Xingmao Ma

CONNECTICUT AGRICULTURE EXPERIMENT STATION

NEW HAVEN, CONNECTICUT

Nanomaterials (NM) are being incorporated into pesticides and fertilizers. Nanomaterial impacts on

agricultural plants and potential trophic transfer is unknown. This lack of understanding is disconcerting

given that food crop contamination is a pathway of human exposure. We will quantitatively characterize

the effects of NMs on crops, focusing on processes relevant to human risk. Based on preliminary data,

65

we hypothesize that agricultural crops accumulate and are physiologically impacted by nanomaterials in a

toxicologically significant fashion with regard to subsequent human exposure.

OBJECTIVES-

1. Determine the uptake, translocation, and toxicity of nanomaterials to crops.

2. Determine the impact of environmental conditions on nanomaterial uptake, translocation, and

toxicity to crops.

3. Determine the potential trophic transfer of nanomaterials.

4. Quantify the facilitated uptake of pesticides through NM-chemical interactions.

We will investigate hydroponic and soil systems to quantify NM uptake, toxicity, trophic transfer, and

NM impacts on the accumulation of co-existing pesticides. Toxicological parameters include biomass,

transpiration, photosynthesis, and ROS generation. Nanomaterial content will be determined by atomic

force microscopy, transmission/scanning electron microscopy, energy dispersive X-ray analysis,

inductively coupled plasma mass spectrometry, and/or synchrotron X-ray absorption near-edge structure.

Trophic transfer will be studied by arthropod-based feeding studies. NMs to be investigated include

carbon nanotubes/fullerenes, Ag, Cu, Au, Si, ZnO, CeO2, TiO2, SiO2, Al2O3.

Nanomaterials are used in agriculture but information on fate and exposure is lacking. Crop

contamination and subsequent trophic transfer represents an uncharacterized route of human exposure.

Nanomaterial interactions with co-existing organic contaminants may increase exposure to other

environmental pollutants.

MITIGATING RISKS OF FOODBORNE ILLNESS ASSOCIATED WITH

HANDLING LEAFY GREENS IN RETAIL FOODSERVICE ESTABLISHMENTS

SERVING AGING POPULATIONS

SUSAN WHOLSDORF-ARENDT (Project Director)

Susan W. Arendt, Catherine H. Strohbehn, Lakshman Rajagopal, Angela M.

Shaw

IOWA STATE UNIVERSITY

AMES, IOWA

Because the American population is aging, with 16% over the age of 62 (21% increase from 2000), the emphasis on food safety in retail foodservice operations is paramount. The use of potentially hazardous fresh produceitems, including leafy greens, can result in foodborne illness if mishandling by foodservice

staff occurs. Additionally, procurement source and form of these items may contribute to microbial risk. Therefore, the goal of this project was to determine and mitigate risk from employee contamination of leafy greens in retail foodservice operations that serve aging Americans.

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Specific objectives follow.

1. Identify current foodservice employee handling practices of leafy greens. 2. Conduct microbial assessment of leafy greens considering procurement form and source and contact

surfaces in the foodservice. 3. Develop effective food safety messaging for foodservice staff about handling leafy greens. 4. Implement and evaluate safe food handling messaging in different foodservice operations (long-term

facilities, hospitals, assisted living facilities, and restaurants) that serve aging Americans with varying risk and health statuses.

5. Disseminate food safety messaging materials through websites and other venues

BUILDING A MULTIDISCIPLINARY FOOD SAFETY TRAINING PIPELINE

FROM K-12 TO GRADUATE SCHOOL

MARTIN WIEDMAN (Project Director)

M. Wiedmann, S. Warchocki, K.J. Boor, A. Orta-Ramirez, K.K. Nightingale, H.F.

Oliver, L.A. Jaykus, L. Johnston, M. Verghese, S. A. Ibrahim

CORNELL UNIVERSITY

ITHACA, NEW YORK

The goal of this project is to develop a multi-institutional program to create and conduct innovative

research and classroom-based graduate and undergraduate food safety training. These efforts are

integrated with K-12 education and training to build a pipeline of students prepared for food safety related

employment. These goals are pursued by a multidisciplinary and multi -institutional team through five

objectives: (1) Develop and conduct science teachers’ workshops that enable the teachers to use food

safety experiments in the classroom and advise students on careers in food safety; (2) Develop and

deliver K-12 food safety activities and experiments to be taught by graduate and undergraduate students;

(3) Develop and conduct a multi-institutional food safety undergraduate summer research program; (4)

Recruit and train undergraduate students through a “food safety track” within existing food science

undergraduate programs; (5) Develop and implement multi-institutional course-based graduate training

programs in food safety. For example, the team conducted > 25 teacher workshops; over 2,000 K -12

students have participated in food safety workshops and other food safety activities; and > 35

undergraduate students participated in food safety summer research. The team also published a paper

that defines food safety core competencies for undergraduate food safety programs, which has been

used to implement a food safety undergraduate concentration at Cornell. We also developed a multi -

institutional graduate level case study-based food safety course, which was offered at Cornell, Texas

Tech, and Purdue. Further information on this project, as well as general food safety information, is

available via Food Safety Wiki.

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ATTACHMENT OF E.COLI 0157:H7 ON PRODUCE AND DAMAGE OF

BACTERIAL CELL ENVELOPE BY DRY PULSED LIGHT (PL), WET PL,

AND PL-SURFACTANT COMBINATIONS

CHANGQING WU (Project Director)

Wenqing Xu and Changqing Wu

UNIVERSITY OF DELAWARE

NEWARK, DELAWARE

It has been showed in our previous study that pulsed light (PL) could potentially be used for

decontamination of Salmonella or E. coli. O157:H7 on green onions as well as raspberries. The

decontamination efficacy varied on different food matrixes. Also, the mechanism of PL to inactive

pathogenic bacteria was not clear. To investigate the inactivation mechanisms of PL and PL-surfactant on

E. coli O157:H7, E. coli O157:H7 cells were attached on glass coverslips and treated by dry PL, wet PL

and PL-surfactant. The ones without treatment served as control. Scanning electron microscopy (SEM)

has been used to observe the bacterial morphological change before and after the treatments. To

compare two different fresh produce, SEM and Cryo-SEM were used to observe the surface structure of

green onions (stems and leaves) and raspberries. The attachment of E. coli O157:H7 as well as their

morphological change after PL treatments have also been compared. The results showed that 1) dry PL

caused intracellular liquid evaporation and led to flatten out on the edge of the cells. Wet PL and PL-

surfactant treated bacterial cells showed more membrane disruption; and 2) the microstructure on the

surface of green onions and raspberries, and 3) different topology of the food matrixes affected bacterial

attachment. PL was proved by the SEM image to have photo-thermal effect on E. coli O157:H7 which

caused a change of cell morphology, membrane disruption, and shrinking of intracellular tissues. Surface

structure of green onions (stems and leaves) as well as raspberries affected the attachment of bacterial

cells and the surface roughness related with bacterial cell envelope structure after PL treatment .

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ENHANCING THE SAFETY AND QUALITY OF FRESH PRODUCE AND LOW-

MOISTURE FOODS BY WATERLESS NON-THERMAL TECHNOLOGIES

VIVIAN WU (Project Director)

Vivian C.H. Wu, David Bridges, and Irwin Quintela

UNIVERSITY OF MAINE

ORONO, MAINE

Consumption of produce and low-moisture foods (LMF) has increased significantly in recent decades.

However, the Food and Drug Administration has recently identified leafy greens, tomatoes, berries, and

almonds as commodities with a high potential risk of pathogen contamination.

The goal of this project is to develop an integrated project among academia, government, industry

partners, and stakeholders to identify and develop effective waterless non-thermal processing

technologies to provide consumers with safe, nutritious, high-quality produce and LMF, and facilitate the

commercialization and dissemination of technologies and knowledge through education and outreach.

This project is expected to provide a comprehensive understanding and a wealth of new knowledge

regarding the effectiveness and mechanisms of inactivating bacterial, viral, and parasitic pathogens by

light and gaseous treatments, to advance the science of food safety. The research outcomes of this

project will fill major knowledge gaps in our understanding of the interactions of treatment parameters,

environmental conditions, and product characteristics in controlling foodborne pathogens on produce and

LMF. This work will also facilitate development of new equipment and processing protocols for industrial

applications, to control the biological hazards on produce and LMF; hence, improving the products’ safety

and reducing foodborne illness. Compared to traditional processing technologies, the proposed

technologies offer many advantages including adaptation to existing processing facilities, feasibility, ease

of scale-up, environmental friendliness, and energy sustainability. The ability to provide effective

microbiological control will be critical to maintaining consumer confidence in the agricultural and food

industries, both in the United States and with international trading partners.

PULSED LIGHT INACTIVATION OF FOODBORNE PATHOGENS


Haiqiang Chen and Kali Kniel

UNIVERSITY OF MAINE

ORONO, MAINE

Pulsed light (PL) is an emerging nonthermal technology that utilizes short, intense pulses of broad

spectrum light (wavelength = 180–1100 nm) to inactivate microorganisms. This technology was adopted

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by the U.S. FDA for food processing in 1996. Use of PL to process food products such as apple juice,

milk, minimally processed vegetables, berries, alfalfa seeds, hot dogs and salmon fillets have been

studied with the intention of extending shelf-life and/or inactivating pathogens. As a physical method, PL

leaves no chemical residues on the produce being treated and would be attractive to both health-

conscious consumers and organic producers. Currently there are two main challenges that limit the PL

application in the food industry. One issue is that PL treatment causes substantial heating of the samples,

which might damage the quality of food. Another issue is that microorganisms on an opaque food surface

must directly face the PL-strobe to be inactivated due to the shallow penetration depth of PL. In this

project, we will use two types of PL treatment systems, dry and wet PL systems. For the dry PL system,

samples will be directly treated by PL while being mechanically rotated. For the wet PL system, samples

will be treated by PL while being immersed in agitated water. These two PL systems will be used to treat

high risk foods for inactivating pathogenic microorganisms. The high risk food include fresh-cut lettuce

and spinach (leEnhancing the Safety and Quality of Fresh Produce and Low-Moisture Foods by

Waterless Non-Thermal Technologiesafy green); carrot (root vegetable); blueberry and tomato (fruits);

and whole peppercorn and almond.

EDUCATION OF CONSUMERS ON FOOD PROCESSING TECHNOLOGIES

USING COOPERATIVE EXTENSION AS THE DELIVERY SYSTEM


Renee R. Boyer, Robert C. Williams and Joell Eifert

UNIVERSITY OF MAINE

ORONO, MAINE

Consumers have a growing concern over the safety of their food supply. There are no educational

campaigns aimed towards educating consumers about food processing technologies. Extension agents

are strongly connected to educational messages related to food and the local food movement.

Additionally, they are viewed as trustworthy sources of information. If Extension agents were equipped

with educational tools to provide programming in food processing technologies, they could have a strong

impact on creating a positive consumer perception. The purpose of this project is to evaluate consumer

perception of food preservation technologies and deliver outreach education to increase their knowledge.

A national telephone survey will be conducted to assess perceptions of various non-thermal food

processing technologies. The survey will evaluate purchasing practices and perceived value of foods

prepared with these technologies. Using results, educational tools will be developed to introduce food

processing key principles and importance of preservation technologies. Material developed will be used to

train Extension agents in the content; and on how they can deliver the materials. Additionally, content will

be disseminated via webinar on eXtension. Agents participating in the training must commit to conduct

outreach to consumers in their locality during the one year following training. Evaluation of the curriculum

and materials will be two fold, targeting consumers participating in agent delivered programming, as well

as evaluating Extension agent knowledge and practice. There are no results to report at this time. Work

for this portion of the project begins in year 2.

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GASEOUS ANTIMICROBIALS FOR PRODUCE AND LOW-MOISTURE FOOD:

EQUIPMENT DEVELOPMENT, SENSORY EVALUATION, MODELING, AND

REGULATORY


Cheng-An Hwang, Lihan Huang, Xuetong Fan

UNIVERSITY OF MAINE

ORONO, MAINE

Produce and low-moisture foods (LMF) are frequently linked to foodborne illnesses caused by bacterial, protozoan, and viral pathogens. Gaseous forms of chlorine dioxide and ozone are advantageous than

the aqueous forms for treating produce and LMF. The objective of this project is to determine the sensory and nutritional quality of selected produce and LMF treated with gaseous chlorine dioxide and ozone and to develop commercial equipment for large-scale applications. It is necessary to search and identify the

optimal processing parameters for producing safe products in large scale while maintaining sensory qualities and meeting the performance standard as required by the regulatory agency. This study will attempt to search for optimal processing parameters (gas concentration, temperature, humidity, and time)

for prcessing produce and LMF, and then evaluate the sensory (odor, color, and texture) and nutritional (e.g., ascorbi acid, lycopene, and antioxidants) quality of products using chemical analyses and instruments. In scaled-up evaluations, existing commercial equipment such as spray washing tunnels for

produce and fluidized-bed dryers for LMF will be modified for gas applications. For products regulated by performance standards, such as almonds requiring a 4‐log reduction of Salmonella on the surface, a

process filing to FDA will be prepared. To support filing, critical process parameters that influence the pathogen reduction will be identified, and mathematical models will be developed to simulate the reduction of foodborne pathogens. The results of this study will be useful for the food industry for

adopting appropriate processes to reduce incidences of foodborne infections.

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CHARACTERIZATION OF HUMAN NOROVIRUS CLINICAL ISOLATES AND

THEIR PATHOGENESIS IN A GNOTOBIOTIC PIG MODEL


Yuanmei Ma, Erin DiCaprio, Xueya Liang, John Hughes, Steven Krakowka,

Jianrong Li

UNIVERSITY OF MAINE

ORONO, MAINE

Human norovirus (NoV) is the leading causative agent of acute nonbacterial gastroenteritis worldwide.

The inability to cultivate human NoV has hampered the development of effective food processing

technologies to eliminate this pathogen from food. The goal of this study is to develop a gnotobiotic pig

model to determine the survival of human NoV upon treatment by food processing technologies.

Gnotobiotic pigs are good models for enteric viruses because pigs resemble humans in their

gastrointestinal anatomy, physiology, and immune responses. In this study, the pathogenesis of two

human NoV GII.4 strains 7I and 5M was determined in newborn gnotobiotic piglets. Gnotobiotic piglets

inoculated with 7 log genomic RNA copies of human NoV GII.4 strain 7I or 5M developed mild to

moderate diarrhea at day 3 post-inoculation. A high level of viral RNA shedding was detected in feces at

days 2-7 post-inoculation. At day 7 post-inoculation, all piglets were terminated and intestinal tissues

were collected for the examination of histopathological changes. It was found that moderate to severe

histologic lesions including villous atrophy, necrosis and apoptosis was observed in duodenum and

jejunum. In addition, a large number of norovirus antigen-containing cells were detected in duodenum and

jejunum tissues using an immunofluorescent assay. Collectively, piglets infected by human NoV

developed diarrhea, viral RNA shedding in feces, pathological changes, and human NoV antigen

expression in small intestine. Thus, gnotobiotic piglets are susceptible for human NoV infection. Future

work will determine the survival of human NoV in gnotobiotic piglets upon treatment by food processing

technologies.

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ENHANCING THE SAFETY AND QUALITY OF FRESH PRODUCE AND LOW-

MOISTURE FOODS BY WATERLESS NON=THERMAL TECHNOLOGIES:

COLD PLASMA AND MONOCHROMATIC LIGHT


Brendan A. Niemira*, Alison Lacombe, Joshua Gurtler, David Kingsley, and

Joseph Sites

UNIVERSITY OF MAINE

ORONO, MAINE

NIFA Project 2015-69003-23410 addresses the urgent need for novel technologies that improve the

safety of fresh and fresh-cut fruits and vegetables that preserve quality while reducing water usage. This

portion of the Project is to investigate emerging non-thermal technologies, such as antimicrobial

monochromatic light and cold plasma. The work will be conducted in three phases: laboratory‐scale,

industrial simulation‐scale, and pilot‐scale studies. The kinetics of processing parameters (e.g.,

concentration, intensity, and time) will be determined for these treatments under various environmental

conditions (e.g., temperature, dose, and humidity), and product characteristics (e.g., tissue makeup,

surface structure, and roughness). This will allow enhancement of the inactivation of foodborne bacterial,

viral, and parasitic pathogens. Individual technologies that are capable of achieving the desired

performance standards for hazard reduction while retaining nutrition and quality will be optimized and

validated for commercial-scale applications. Combinations of successful technologies will be similarly

validated to ensure high product quality under conditions that ensure inactivation of pathogens. A cooling

tunnel and chamber will be used to simulate commercial processing so as to fine-tune the treatment

parameters for large sample volumes. Finally, we will collaborate with our industry partners to conduct

scale‐up studies with the optimized technologies. We expect that with these optimized technologies,

processors will be able to reduce inputs of energy and water, and will see overall improved efficiencies in

the production of safer fresh produce.

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INVESTIGATION OF POLYMER-FUNCTIONALIZED CARBON NANOTUBE-

COATED FILTERS FOR REMOVAL OF BACTERIAL PATHOGENS

LIJU YANG (Project Director)

Shengyuan Wang, Gregory E. LeCroy, Fan Yang, Xiuli Dong,Ya-Ping Sun, Liju

Yang

NORTH CAROLINA CENTRAL UNIVERSITY

DURHAM, NORTH CAROLINA

A major challenge in food safety for both preventing and responding to the contamination of human

pathogens is that the numbers of the pathogens in most food samples are relatively low, so that effective

isolation and concentration are necessary to enable rapid detection and analyses. Carbon nanotubes

(CNTs) are well-ordered, hollow carbon fibers with a high aspect ratio. CNTs have been explored for a

wide range of biological applications exploiting their remarkable properties. Research results obtained in

our laboratories and by others have demonstrated two major promising activities of CNTs in the

microbiology field: strong antimicrobial activity for inactivation of bacterial cells and highly absorptivity for

removing biological contaminants using CNTs-based filters. While most of the studies on CNTs’

adsorption to bacterial cells have been focused on the use of CNTs in suspensions, this study explored

CNTs’ strong adsorption to bacterial cells on CNTs-coated surfaces. CNTs were first functionalized with

oligomeric poly(propionylethyleneimine-co-ethyleneimine (PPEI-EI). Polycarbonate membranes with

different pore sizes were coated with PPEI-EI-CNTs, and evaluated for removal of bacterial cells.

Currently, two PPEI-EI-CNTs samples with different percentage of functionalization showed effective

removal of E. coli cells by approximately 2 log and 4-5 log reduction on 3.0 µm and 1.2 µm pore sized

filters, respectively. Investigation on the effects of various factors, including CNT composite fraction, CNT

coating density, CNT crosslink efficiency, and filtration rate, on the removal of bacterial cells are in

progress. It is expected that PPEI-EI functionalized CNT filters can effectively remove bacteria under

optimized functionalization and operating conditions.

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STORAGE AND SENSORY EVALUATION OF SELECTED MAPS PRODUCTS

TOM YANG (Project Director)

Tom Yang

NATICK

NATICK, MASSACHUSETTS

The WSU 40 kW 915 MHz system was used to produce MAPS samples and ship to US Army Natick RDE

Center for storage and sensory evaluation. USANSC has developed a standard protocol for evaluating

quality of food developed using new processing technologies (inc luding MW sterilization and high

pressure assisted sterilization).

Impacts: To ensure the safety and quality of the MAPS products stored at normal (44 oF) and abused (54

oF) refrigeration condition during a designated storage period (10 weeks)

Outputs: Microbial tests and sensory evaluation of the three MAPS-processed samples: macaroni and

cheese, deviled egg potato salad, and buffalo chicken pasta salad were complete after 10 week storage.

The MAPS samples showed no bacterial growth and the sensory attributes showed no significant

difference after storing at both 44 oF and 54 oF. The samples have been well received.

AROMATIC CARBON-DEGRADING MICROORGANISM-MEDIATED UPTAKE

OF CARBON NANOTUBES BY TOMATO PLANTS

YU YANG (Project Director)

Yu Yang

UNIVERSITY OF NEVADA RENO

RENO, NEVADA

Nanotechnology industry has threatened food safety, as engineered nanomaterials can enter agricultural

systems through sludge application, waste water irrigation and air deposition. Carbon nanotubes (CNTs),

one of the most widely applied nanomaterials, are accumulated in agricultural system with the soil

concentration increasing by 0.4-157 ng/kg/year. CNTs can be uptaken by agricultural plants and

translocated to fresh produce, if the barrier for their uptake is overcome by environmental reactions. It is

still unknown how microbial activities mediate the plant uptake of CNTs and their accumulation in fresh

products. This study is focused on aromatic carbon-degrading microorganism-mediated uptake of CNTs

by tomato. We hypothesize that aromatic carbon-degrading microorganism can potentially transform

CNTs to more hydrophilic, increase their aqueous stability and enhance their plant uptake. We will

examine the transformation and degradation of CNTs by aromatic carbon-degrading bacteria and fungi.

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CNTs will be characterized before and after incubation with microorganisms. Tomato uptake of CNTs in

the presence of aromatic carbon-degrading microorganisms will be analyzed in the hydroponic culture.

Potential results will provide critical information for evaluating the fate of CNTs in agricultural system and

their concentration in fresh produce. As a seed project, preliminary data produced will be used for

pursuing complete understanding about the impacts of engineered nanoparticles on fresh products. This

project is targeting Improving Food Safety-A1331, under the program area of Food Safety, Nutrition and

Health.

PROTECTIVE SURFACE COATING TO REDUCE BACTERIAL LOAD OF

FRESH AND FRESH-CUT PRODUCE: CATALOUPE AS A MODEL

YUAN YAO (Project Director)

Yuan Yao, Arun Bhunia, Preetam Sarkar, Yezhi Fu, Amanda Deering

PURDUE UNIVERSITY

WEST LAFAYETTE, INDIANA

This presentation reports our progress with the project “Protective surface coating to reduce bacterial load

of fresh and fresh-cut produce: cantaloupe as a model” sponsored by the Program Area of “Improving the

Safety of Fresh and Fresh-Cut Produce” of the AFRI Food Safety Program. Fresh and fresh-cut produce

have been a major cause of foodborne illnesses. Among all produce, cantaloupe is particularly

susceptible to both Gram-positive and negative pathogens. The goal of this project is to create a

technology platform for designing antimicrobial formulations which need negligible capital investment and

minimal material cost to protect fresh and fresh-cut produce. Thus far, we have made progress in several

aspects. (1) We have studied the properties of emulsion systems in prolonging the efficacies of two

antimicrobial compounds, nisin and thymol, in fresh-cut cantaloupe models. In emulsions, partial

immobilization of antimicrobial compounds reduced their chemical degradation and physical loss and thus

effectively retained their inhibitory concentration against pathogens over a longer period of time. (2) To

evaluate the efficacy of antimicrobial coating against pathogen biofilms formed at cantaloupe surface, we

need to simulate and characterize the formation of biofilms. For this, we established a cryo-SEM

procedure to monitor the growth of biofilms of Listeria monocytogenes, E. coli O157:H7, and Salmonella

Typhimurium. Based on this, we preliminarily determined the resistance of pathogen biofilms against

antimicrobial treatments.

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A LONGITUDINAL STUDY ON CAMPYLOBACTER PREVALENCE IN

CONVENTIONALLY-RAISED COMMERCIAL BROILER FLOCKS IN THE

UNITED STATES

QIJING ZHANG (Project Director)

Orhan Sahin, Nada Pavlovic, Annette O'Connor, Catherine Logue, and Qijing

Zhang


AMES, IOWA

Campylobacter is highly prevalent in poultry and contaminated poultry meat is a significant source of

infection for human campylobacteriosis, a leading cause of bacterial foodborne gastroenteritis. Thus,

reduction Campylobacter in poultry production will have a significant impac t on food safety and public

health. The purpose of this study was to conduct a longitudinal epidemiological study to identify the risk

factors associated with variation in Campylobacter prevalence in U.S. commercial broiler production.

Cecal contents (15/flock) and boot swabs (3/flock) were collected from 5-6 week-old birds from 369

conventional broiler flocks on 15 different farms (53 houses) at 8 consecutive production cycles over 18

months and cultured for Campylobacter. Prevalences of Campylobacter at the farm, house, and flock

levels are found to be 93.3%, 77.3%, and 45.2%, respectively. The mean level of Campylobacter

numbers in positive flocks was 5.3 log10 CFU/g feces by cecal contents and 3.4 log10 CFU/g feces by

boot swabs. Campylobacter prevalence varied remarkably among different farms, houses and flocks, with

some houses/farms testing consistently negative while others positive all the time over the entire

sampling period. Majority of isolates identified as C. jejuni by PCR. Initial genotyping results via PFGE

suggest persistence of few C. jejuni clones over multiple production cycles on the same farm. This study

indicated the presence of management, environmental and/or host factors that influence the prevalence

of Campylobacter on poultry farms. Identification of on-farm risk factors associated with Campylobacter

prevalence is currently being performed.

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PREVALENCE OF A HIGHLY VIRULENT CAMPYLOBACTER JEJUNI CLONE

ASSOCIATED WITH SHEEP ABORTION IN FEEDLOT CATTLE IN THE

UNITED STATES

QIJING ZHANG (Project Director)

Yizhi Tang, Orhan Sahin, Nada Pavlovic, Jeff Lejeune, James Carlson, and

Qijing Zhang


AMES, IOWA

A highly pathogenic, tetracycline-resistant C. jejuni clone (clone SA) has emerged as the predominant

Campylobacter species causing sheep abortion in the U.S. during the last decade. Clone SA is also a

zoonotic pathogen transmitted mainly via raw milk consumption and causing gastroenteritis in humans.

This study was conducted to determine the prevalence and distribution of clone SA on multiple cattle

farms across the U.S. A total of 3,184 fecal samples were collected from 66 different feedlot cattle in

Iowa, Texas, Colorado, Missouri and Kansas, and cultured for Campylobacter. Overall prevalence of

Campylobacter was 72% (2293/3184). PCR identified majority of the isolates (82.6%, 1893/2293) as C.

jejuni, and most of the rest was C. coli (89%, 356/400). Within C. jejuni 8.7% (164/1893) were initially

identified as clone SA using a gene-specific PCR. Further confirmation by pulse-field gel electrophoresis

(PFGE) revealed that 112 of these isolates as clone SA, giving an overall prevalence of rate of 5.9%

(112/1893). The prevalence of clone SA varied by state: 1.8% (14/759) in Colorado, 2.1% (17/800) in

Iowa, 3.2% (24/750) in Kansas, 5.0% (15/300) in Missouri, and 7.3% (42/575) in Texas. Also, a total of

693 dairy cow milk filters from different farms were cultured for Campylobacter. Eleven (1.5%) were found

culture positive, all of which were identified as C. jejuni via PCR, but none was clone SA. These findings

indicate that Campylobacter is commonly prevalent in the U.S. feedlot cattle, and that clone SA

constitutes a substantial portion of the commensal cattle C. jejuni population.

MOLECULAR MECHANISMS UNDERLYING SALMONELLA ATTACHMENT TO

FRUITS AND NUTS

WEI ZHANG (Project Director)

Ye Li, Joelle Salazar, Mary Lou Tortorello, Michael McClelland, Wei Zhang

ILLINOIS INSTITUTE OF TECHNOLOGY

BEDFORD PARK, ILLINOIS

Salmonella is frequently implicated in foodborne disease outbreaks associated with fruits, spices and

nuts. The overall goal of this project is to identify and characterize bacterial determinants, food attributes,

78

and environmental factors that collectively affect the attachment and survival of Salmonella on the surface

of different fruits and nuts in order to gain new knowledge regarding the physiology of this pathogen and

to develop effective control measures to reduce its contamination. In the first year of this project, we

compared the two common Salmonella enterica serovars, i.e. S. Enteritidis and S. Typhimurium linked to

contaminated fruits and nuts. Significant differences were detected between two Salmonella serovars for

their relative capabilities of attaching to black pepper, almonds and hazelnuts under ambient storage

conditions. S. Typhimurium was found to grow more readily than S. Enteritidis on nut surfaces; bacteria

attached significantly better to black pepper than to almonds and hazelnuts. A newly constructed bar-

coded transposon library of S. Enteritidis was used to functionally screen for Salmonella genes important

for surface attachment using black pepper as a model. Bacterial genomic DNA samples were collected

for high-throughput sequencing analysis. So far, we identified a total of 220 genes in S. enterica genome

that displayed significant (FDR < 10%) selection under the experimental conditions. Transposon mutants

in flagella genes appeared to be more fit whereas mutants in DNA repair systems were less fit, indicating

that DNA repair systems play a very important role in S. enterica attachment and survival on nut surface.

REDUCTION OF SHIGA TOXIN-PRODUCING E.COLI AND SALMONELLA

TYPHIMURIUM ON CATTLE HIDES BY SPRAY TREATMENT WITH

LEVULINIC ACID PLUS SODIUM DODECYL

TONG ZHAO (Project Director)

Tong Zhao, Luxin Wang, Ping Zhao, Dong Chen, and Michael P. Doyle


ATHENS, GEORGIA

The purposes of this study was to determine the efficacy of levulinic acid plus sodium dodecyl sulfate

(SDS) to inactivate STEC and Salmonella Typhimurium on cattle hides as a surface spray treatment at

different concentrations in vitro.

A mixture of six isolates of STEC, including serovars O26, O45, O103, O111, O121, and O157 and a

mixture of 5 strains of S. Typhimurium were sprayed on the surface of 10 x 10-cm sections of cattle hide.

The inoculated hides were dried under a hood at either 21oC or 4oC for 72 h. The hides were treated by

surface spray with a microbicide comprised of levulinic acid plus sodium dodecyl sulfate at different

concentrations at 45 psi for 15 s. Water only was used as the negative control. Sponge samples of the

hides were collected at 1, 3, and 5 min after treatment and enumerated for STEC and Salmonella. For

STEC-contaminated hides, 3% levulinic acid plus 0.5% SDS for 5 min reduced STEC populations by 2.3

log/cm2, compared to the water only treatment. For S. Typhimurium-contaminated hides, treatment with

2% levulinic acid plus 0.2% SDS reduced the Salmonella population by 3.2 log/cm2. Scrubbing hides

with a brush processing for 30 s followed by the microbicide spray treatment further reduced Salmonella

contamination by 0.5 log/cm2. However, for wet hides, a spray treatment with 4% levulinic acid plus 2%

SDS for 5 min reduced Salmonella by only 1.3 log cfu/cm2 when compared with the water-only treatment.

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A VISIBLE LIGHT PHOTOCATALYST BI2CuO4 FOR BACTERICIDAL

APPLICATIONS

YIPING ZHAO (Project Director)

Lu Zhu, Les P Jones, Steven Larson, Ralph A. Tripp, and Yiping Zhao


ATHENS, GEORGIA

Photocatalytic material embedded coatings shown great promise as effective disinfectants over a range

of microorganisms. However, to take the advantage of the general grocery store and household lighting

conditions, visible light driven photocatalytic materials are needed to reduce the pathogen contaminations

when incorporated into surface coating or food packaging. In this study, narrow bandgap semiconductor

Bi2CuO4 nano- and micro-particles are fabricated through a facile hydrothermal synthesis approach, and

are used as the photocatalysts for antibacterial applications. The as-synthesized samples show the light

absorption for a wide range of wavelength up to near infrared range, and demonstrate a strong

photocatalytic performance with methylene blue photodecay rate of 0.114 h-1 and ~93% bactericidal

inactivation of Escherichia coli under visible light illumination. Comparing with other structures, the

hierarchical micro-flower shaped Bi2CuO4 sample shows better performance. These results indicate that

Bi2CuO4 powder materials can be a promising candidate for visible light driven antimicrobial applications

for food packaging industries.

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PROJECT DIRECTOR MEETING ATTENDEES

Name Institution/Organization Roles

Adcock, Flynn Texas A&M AgriLife Research

Altier, Craig Cornell University

Anderson, Ben UGA Center for Food Safety

Barnes, Stephanie University of Georgia

Belk, Keith Colorado State University

Bergholz, Peter North Dakota State University

Bergholz, Teresa North Dakota State University

Besong, Samuel Delaware State University

Besser, Thomas Washington State University Oral Presenter

Bezbaruah, Achintya North Dakota State University

Bhunia, Arun Purdue University

Boakye, Prince Delaware State University

Boateng, Judith Alabama A&M University

Bohnet, Stewart Washington State University

Bosilevac, Mick USDA ARS USMARC

Boyer, Renee Virginia Tech

Bozkurt Cekmer, Hayriye University of Tennessee Knoxville

Brehm-Stecher, Byron Iowa State University

Chen, Fur-Chi Tennessee State University

Chen, Haiqiang University of Delaware

Chen, Hongda

USDA National Institute of Food and

Agriculture USDA NIFA IFSN NPL

Chen, Jinru University of Georgia

Cui, Yue University of Georgia

Datta, Ashim Cornell University

Davidson, P. Michael University of Tennessee

Diez, Francisco University of Minnesota

D'Souza, Doris University of Tennessee-Knoxville

Dunne, C. Patrick USDA NIFA Keynote Speaker Keynote Speaker

Eblen, Denise USDA National Institute of Food and Agriculture

USDA NIFA IFSN Deputy Director

Esseili, Malak Ohio State University

Fan, Xuetong USDA/ARS/ERRC

Feist, Shelley Partnership for Food Safety Education

Frank, Joseph University of Georgia

Fridman, Alexander Drexel University

Fridman, Gregory Drexel University

Funk, Julie Michigan State University Oral Presenter

Gibson, Kristen University of Arkansas

Godwin, Sandria Tennessee State University

Gray, Denis North Carolina State University

Gray, Peter Washington State University

Green, Kim USDA/OSEC/OCS

USDA Office of the

Secretary

Gurtler, Joshua USDA, ARS

81


Hashem, Fawzy

University of Maryland Eastern

Shore

He, Lili

University of Massachusetts-

Amherst

Hesketh, Peter Georgia Institute of Technology

Huang, Ching-Hua Georgia Institute of Technology

Huang, Lihan USDA/ARS/ERRC

Hung, Yen-Con University of Georgia Oral Presenter

Hunter, Jessie University of Idaho

Hwang, Andy USDA/ARS/ERRC

Ingham, Barbara University of Wisconsin

Isaacson, Richard University of Minnesota

James-Holly, Dawanna


Agriculture USDA NIFA IFSN PS

Jaroni, Divya Oklahoma State University

Jaykus, Lee-Ann North Carolina State University Oral Presenter

Jenkins, Daniel University of Hawaii

Jeong, K. Casey University of Florida

Jeong, Sanghyup Michigan State University

Karwe, Mukund Rutgers University

Kassama, Lamin Alabama A&M University

Kathariou, Sophia North Carolina State University

Kauffman, Michael Ohio State University

Kennedy, Shaun The Food System Institute

Khouryieh, John Western Kentucky University

Kilonzo, Agnes Tennessee State University Oral Presenter

Kingsley, David USDA ARS FSIT

Kong, Fanbin University of Georgia

Koo, Jaheon University of Arkansas at Pine Bluff.

Kubota, Ryo University of Hawaii at Manoa

Lacombe, Alison USDA/ARS

Law, Bibiana The University of Arizona Oral Presenter

Lazouskaya, Volha University of Delaware

Lee, Hyun Jung University of Idaho

Lee, Wan-Ning Georgia Institute of Technology

LeJeune, Jeffrey Ohio State University

Leon, Juan Emory University

Li, Jianrong Ohio State University

Li, Yong University of Hawaii at Manoa

Lin, Huimin Washington State University

Liu, Frank Washington State University

Liu, Lingling University of Georgia

Liu, Shuxiang Washington State University

Luchansky, John USDA-ARS

Manohar, Manu



McGowen, Lindsey North Carolina State University

McNealy, Tamara Clemson University

82


Mellata, Melha Arizona State University

Micallef, Shirley University of Maryland

Mir, Raies University of Florida

Moore, Dale Washington State University

Morant, Mervalin



Morley, Paul Colorado State University

Morrow, Kristen Arizona State University

Moxley, Rodney University of Nebraska-Lincoln Oral Presenter

Nagaraja, TG Kansas State University

Neal, Jack

University of Houston/Conrad N

Hilton College of HRM

Nguyen, Helen University of Illinois

Niemira, Brendan USDA-ARS

Nitin, Nitin University of California, Davis

Nugen, Sam University of Massachusetts

Orlandi, Palmer Food and Drug Administration

Ovissipour, Mahmoudreza Washington State University

Pahl, Donna University of Maryland

Parikh, Sanjai University of California, Davis

Patras, Ankit Tennessee State University

Pestka, James Michigan State University Oral Presenter

Pivarnik, Lori University of Rhode Island

Porto-Fett, Anna USDA-ARS

Pradhan, Abani University of Maryland

Pruden, Amy Virginia Tech

Rajagopal, Lakshman Iowa State University

Rajashekara, Gireesh Ohio State University

Rangel, Lorena University of California, Davis

Rao, Ramkishan



Rasco, Barbara School of Food Science

Reich, John



Rodriguez, Roberto University of Hawaii at Manoa

Rosenthal, Benjamin USDA/ARS

Rose, Joan Michigan State University

Rosson, Parr Texas A&M University

Ryser, Elliot Michigan State University

Ryu, Dojin University of Idaho Oral Presenter

Sablani, Shyam Washington State University

Sahin, Orhan Iowa State University

Salvi, Deepti Rutgers University

Scott, H. Morgan Texas A&M University Oral Presenter

Senapati, Satyajyoti University of Notre Dame

Shah, Sunny University of Notre Dame

Shaw, Angela Iowa State University

Singer, Randall University of Minnesota

83


Singleton, Jan


Agriculture

USDA NIFA IFSN Food Safety Division

Director

Sischo, William Washington State University

Smith, Tara Kent State University

Steenhuis, Tammo Cornell University

Stelzleni, Alex University of Georgia

Su, Yi-Cheng Oregon State University

Suehr, Quincy Michigan State University

Sun, Gang University of California, Davis

Sun, Taozhu University of Delaware

Suslow, Trevor University of California

Tadapaneni, Ravi Washington State University

Tang, Juming Washington State University Oral Presenter

Tao, Shiquan West Texas A&M University

Taylor, Matthew Texas A&M University

Teplitski, Max University of Florida Oral Presenter

Thurston, Jeanette



Trimble, Lisa University of Georgia

Walls, Isabel



Wang, Qiuhong Ohio State University

White, Jason

Connecticut Agricultural

Experiment Station

Wiedmann, Martin Cornell University

Williams, Jodi



Wittum, Thomas Ohio State University Oral Presenter

Wright, Katie University of Arkansas

Wu, Changqing University of Delaware

Wu, Vivian Chi-Hua University of Maine

Xu, Jie Washington State University

Yang, Liju North Carolina Central University

Yang, Yu University of Nevada, Reno

Yao, Yuan Purdue University Oral Presenter

Younce, Frank Washington State University

Zhang, Wei Michigan State University

Zhang, Wei Illinois Institute of Technology

Zhao, Tong University of Georgia

84

CONFERENCE MENU

Portland Steel Bridge Continental Breakfast

Seasonal sliced fruit, old fashioned oatmeal, cinnamon brown sugar, craisins,

Butter croissants, coffee cake, banana bread, muffins, butter and preserves

Toaster Station

Toast, Assorted Bagels with Cream Cheese

Beverages

Assorted Juices

Coffee and Tea

Portland Pearl District Lunch

Smoked turkey breast, honey glazed ham, roast beef, Tillamook cheddar, Swiss cheese,

Sliced tomatoes, green leaf lettuce, red onion, kosher pickle spears, and pepperoncini

Salads

Penne pasta salad or Potato salad

Breads

Sliced breads: sourdough, nine-grain, and white

Dessert

Fresh-baked Cookies and Brownies

Hot Beverages

House-brewed Coffee and Tea

Traditional Condiments

85

ACKNOWLEDGING USDA-NIFA

Proper acknowledgement of your funding in posters, abstracts,

project websites, published manuscripts, presentations, press

releases, etc. is critical to the success of food safety programs.

If funded by USDA-NIFA, we anticipate that you will use the

following language to acknowledge NIFA support, as

appropriate:

“This project was supported (or partially supported) by AFRI food

safety grant no. XXXX-XXXXX-XXXXX from the USDA National

Institute of Food and Agriculture.”

We also expect that you will use our agency’s official identifier

logo (http://www.nifa.usda.gov/about/offices/nifa_logo.html) in all

of your slide and poster presentations resulting from your grant

award.

Please alert us of significant findings, publications, news releases,

and other media coverage of your work. With your permission, we

may highlight your project in a National Impact story or News

Release. If your research is featured on the cover of a scientific

journal, we can showcase the cover as well. Examples of these

publications can be found in our Newsroom

(http://www.nifa.usda.gov/newsroom/newsroom.html).

***************************************************************************

http://www.nifa.usda.gov/newsroom/newsroom.html

86

USDA NIFA IFSN Food Safety Division

Thank you for your active engagement in the 2015 food

safety project director meeting and for advancing food

safety related science through the accomplishments of

your funded projects.

Jan Singleton, PhD, RDN NIFA Food Safety Division Director, [email protected]

Isabel Walls, PhD, National Program Leader, [email protected]

Jodi Williams, PhD National Program Leader, [email protected]

Jeanette Thurston, PhD National Program Leader, [email protected]

Hongda Chen, PhD National Program Leader, [email protected]

Dawanna James-Holly, PhD, Program Specialist, [email protected]

John Reich, PhD Program Specialist, [email protected]

Mervalin Morant, PhD National Program Leader, [email protected]

Manu Manohar, PhD Program Specialist, [email protected]

Ramkishan Rao, PhD National Program Leader, [email protected]

For additional Information on the food safety programs, go to the NIFA Food Safety website at

http://nifa.usda.gov/program/food-safety

mailto:[email protected]








Documents

OREGON CONVENTION CENTER USDA NIFA, …caes2.caes.uga.edu/research/beefsafety/documents/JULY242015PDS...kira newman, lee-ann jaykus, juan s. leon.....47 plant microbiota-driven facilitation