Upload
others
View
8
Download
0
Embed Size (px)
Citation preview
1
The Role of Microbiological Testing and Microbiological
Criteria in an Evolving Regulatory Environment
The Role of Microbiological Testing and Microbiological
Criteria in an Evolving Regulatory Environment
International Commission on Microbiological Standards for Foods
Washington, D.C. October 31, 2005
Robert E. Brackett, Ph.D.Director, Center for Food Safety and Applied Nutrition
Food and Drug Administration
International Commission on Microbiological Standards for Foods
Washington, D.C. October 31, 2005
Robert E. Brackett, Ph.D.Director, Center for Food Safety and Applied Nutrition
Food and Drug Administration
Microbial TestingMicrobial Testing• Why test?
– Safety of “batches”– Investigational sampling– Surveillance – Process control– Quality control/assurance
• Why test?– Safety of “batches”– Investigational sampling– Surveillance – Process control– Quality control/assurance
2
Microbial TestingMicrobial Testing• Why test?
– Safety of “batches”– Investigational sampling– Surveillance– Process control– Quality control/assurance
• Why test?– Safety of “batches”– Investigational sampling– Surveillance– Process control– Quality control/assurance
The “Poison Squad”The “Poison Squad”
3
Microbial TestingMicrobial Testing
• Microbiological testing is almost always an important component of any integrated program to assure the safety of foods
• Microbiological testing is almost always an important component of any integrated program to assure the safety of foods
4
Testing for SafetyTesting for Safety
• Detection and identification• Detection and identification
Testing for SafetyTesting for Safety
• Detection and identification– Traditional Plating
• Detection and identification– Traditional Plating
5
Traditional Microbiological Plating
Plating on Sorbitol-MacConkey
K-12 Strain 868
Traditional Microbiological Plating
Plating on MUG for β-glucuronidase
6
Testing for SafetyTesting for Safety
• Detection and identification– Traditional Plating– “Rapid” Tests
• Miniaturized tests• Gene probes• Enzyme-linked immunosorbant assays
(ELISA)• Polymerase Chain Reaction (PCR)• Biosensors
• Detection and identification– Traditional Plating– “Rapid” Tests
• Miniaturized tests• Gene probes• Enzyme-linked immunosorbant assays
(ELISA)• Polymerase Chain Reaction (PCR)• Biosensors
SampleBiologicallysensitivecoatingSensor
Transducer
Output
7
Testing for SafetyTesting for Safety
• Detection and identification• Enumeration
– Most probable number (MPN)– Plate counts– Instrumental methods
• Flow cytometry– RT-Polymerized Chain Reaction (RT-
PCR)
• Detection and identification• Enumeration
– Most probable number (MPN)– Plate counts– Instrumental methods
• Flow cytometry– RT-Polymerized Chain Reaction (RT-
PCR)
1 2 3 4 5 6 7
Mean Log cfu/gMean Log cfu/g
0.0
0.1
0.2
0.3
0.4
0.5
Pro
babi
lity
den
sity
Pro
babi
lity
den
sity
What does “the count” mean?
8
Testing for SafetyTesting for Safety• Detection and identification• Enumeration• Attribution
– Gram stain– Morphology– Biochemical tests– Immunological
• Serotyping• ELISA
– Molecular• Pulse field gel electrophoresis• Multilocus sequence typing• Cladistic analysis
• Detection and identification• Enumeration• Attribution
– Gram stain– Morphology– Biochemical tests– Immunological
• Serotyping• ELISA
– Molecular• Pulse field gel electrophoresis• Multilocus sequence typing• Cladistic analysis
Outbreak Response:S. Agona in Cereal
Bacteria from the food and patients were the same
Matched using DNA finger print, which is read like a bar code (PulseNet)
PatientPatient FoodFood DifferentDifferentSalmonellaSalmonella
9
Microbiological CriteriaMicrobiological Criteria
What are “Criteria”?What are “Criteria”?
• Criterion– Standard: Must meet, regulatory
requirement– Guideline: Should meet, GHP– Specification: Expected to meet,
generally used to describe an agreement between a supplier and a purchaser
• Criterion– Standard: Must meet, regulatory
requirement– Guideline: Should meet, GHP– Specification: Expected to meet,
generally used to describe an agreement between a supplier and a purchaser
10
Examples of Microbiological Criteria
Examples of Microbiological Criteria
• Indicator organisms– Presence or populations of organism
statistically associated with a pathogen• Coliforms, fecal coliforms, E. coli
• Indicator organisms– Presence or populations of organism
statistically associated with a pathogen• Coliforms, fecal coliforms, E. coli
Examples of Microbiological Criteria
Examples of Microbiological Criteria
• Indicator organisms• Target pathogens
–None detected • “Zero Tolerance”
–Attribute estimate (e.g. X positive samples in Y total samples)
–Point value limit (e.g. 100 cfu/g)• “Bright Shining Line”
• Indicator organisms• Target pathogens
–None detected • “Zero Tolerance”
–Attribute estimate (e.g. X positive samples in Y total samples)
–Point value limit (e.g. 100 cfu/g)• “Bright Shining Line”
11
Microbiological CriteriaMicrobiological Criteria
• Do the criteria have ANY theoretical or demonstrable relationship to public health?
• Do the criteria have ANY theoretical or demonstrable relationship to public health?
Microbiological CriteriaMicrobiological Criteria
• Do the criteria have ANY theoretical or demonstrable relationship to public health?
• What qualitative or quantitative values best assure the safety of foods?
• Do the criteria have ANY theoretical or demonstrable relationship to public health?
• What qualitative or quantitative values best assure the safety of foods?
12
1 2 3 4 5 6 7
Mean Log cfu/gMean Log cfu/g
0.0
0.1
0.2
0.3
0.4
0.5
Pro
babi
lity
den
sity
Pro
babi
lity
den
sity
What does “the count” mean?
UNSAFE
SAFE
Perceived Prediction of Safety
13
UNSAFE
Less Safe
Safer
SAFE
Realistic Estimation of Safety
Defining Question
How Does One Choose the “Right” Value?
Defining Question
How Does One Choose the “Right” Value?
14
Changes in Philosophy to Assure Safe Foods
Changes in Philosophy to Assure Safe Foods
• Microbiological Testing for Safety• Microbiological Testing for Safety
Changes in Philosophy to Assure Safe Foods
Changes in Philosophy to Assure Safe Foods
• Microbiological Testing for Safety• Preventative Controls• Microbiological Testing for Safety• Preventative Controls
15
Preventative ControlsPreventative Controls
• Good Manufacturing/Agricultural Practices– Minimum practices to reasonably
assure sanitation, etc.– Foundation for HACCP
• Good Manufacturing/Agricultural Practices– Minimum practices to reasonably
assure sanitation, etc.– Foundation for HACCP
Preventative ControlsPreventative Controls• Good Manufacturing Principals• Hazard Analysis Critical Control Points
(HACCP)– Focuses on identifying and preventing hazards
from contaminating food – Based on sound science – Permits more efficient and effective government
oversight, – Places responsibility for ensuring food safety
appropriately on the food manufacturer or distributor
– Reduces barriers to international trade.
• Good Manufacturing Principals• Hazard Analysis Critical Control Points
(HACCP)– Focuses on identifying and preventing hazards
from contaminating food – Based on sound science – Permits more efficient and effective government
oversight, – Places responsibility for ensuring food safety
appropriately on the food manufacturer or distributor
– Reduces barriers to international trade.
16
Changes in PhilosophyChanges in Philosophy
• Microbiological Testing for Safety• Preventative Controls• “Outcome Based” Food Safety
• Microbiological Testing for Safety• Preventative Controls• “Outcome Based” Food Safety
Changes in PhilosophyChanges in Philosophy• Microbiological Testing for Safety• Preventative Controls• “Outcome Based” Food Safety
– National Public Health Goals
• Microbiological Testing for Safety• Preventative Controls• “Outcome Based” Food Safety
– National Public Health Goals
17
Changes in PhilosophyChanges in Philosophy
• Microbiological Testing for Safety• Preventative Controls• “Outcome Based” Food Safety
– National Public Health Goals– Risk Management Framework
• Microbiological Testing for Safety• Preventative Controls• “Outcome Based” Food Safety
– National Public Health Goals– Risk Management Framework
Risk ManagementRisk Management
• It is all about making decisions– Have to establish the level of protection
deemed appropriate to safeguard the public
– That level is both a scientific and a societal decision
– Risk assessment is making it possible to link control measure to pubic health impact
• It is all about making decisions– Have to establish the level of protection
deemed appropriate to safeguard the public
– That level is both a scientific and a societal decision
– Risk assessment is making it possible to link control measure to pubic health impact
18
Risk Management ConceptRisk Management Concept
• The degree of “regulatory control” placed on a pathogen-food pair should be a function of the risk to public health
• The degree of “regulatory control” placed on a pathogen-food pair should be a function of the risk to public health
“Outcome Based” Food Safety“Outcome Based” Food Safety
• Quantitative Risk Assessments– Salmonella Enteritidis in Shell Eggs
(USDA/FDA)– Listeria monocytogenes in Ready-to-
Eat Foods (FDA/USDA, WHO)– Vibrio vulnificus in molluscan
shellfish (FDA)– Vibrio parahaemolyticus in seafood
(FDA)
• Quantitative Risk Assessments– Salmonella Enteritidis in Shell Eggs
(USDA/FDA)– Listeria monocytogenes in Ready-to-
Eat Foods (FDA/USDA, WHO)– Vibrio vulnificus in molluscan
shellfish (FDA)– Vibrio parahaemolyticus in seafood
(FDA)
19
Impact of Risk Analysis Framework
Impact of Risk Analysis Framework
• Being able to better link food safety activities to public health outcomes via risk assessments has allowed:– New concepts to be considered
• Food Safety Objective (FSO)• Appropriate Level of Protection (ALOP)• Performance Objective (PO)
• Being able to better link food safety activities to public health outcomes via risk assessments has allowed:– New concepts to be considered
• Food Safety Objective (FSO)• Appropriate Level of Protection (ALOP)• Performance Objective (PO)
Food Safety ObjectiveFood Safety Objective
• An FSO can be viewed an a “bright shining line”
• By definition–Below is safe–Above is not safe
• PO is the equivalent at a specified point earlier in the food chain
• An FSO can be viewed an a “bright shining line”
• By definition–Below is safe–Above is not safe
• PO is the equivalent at a specified point earlier in the food chain
20
Impact of Risk Analysis Framework
Impact of Risk Analysis Framework
• Being able to better link food safety activities to public health outcomes via risk assessments has allowed:– New concepts to be considered – Old concepts to be put on a more scientific
basis• Performance criteria• Process criteria• Product criteria• Microbiological criteria
• Being able to better link food safety activities to public health outcomes via risk assessments has allowed:– New concepts to be considered – Old concepts to be put on a more scientific
basis• Performance criteria• Process criteria• Product criteria• Microbiological criteria
The Evolving Regulatory Environment
The Evolving Regulatory Environment
21
The Evolving Regulatory Environment
The Evolving Regulatory Environment
• Massive and Revolutionary changes are occurring which affect Regulatory Policy
• Massive and Revolutionary changes are occurring which affect Regulatory Policy
Change #1Changes in Philosophy
Change #1Changes in Philosophy
22
Past PhilosophyPast Philosophy• Command and control
– Pasteurized Milk Ordinance (PMO) –1924
– Low-Acid Canned Foods – 1973, 1979– Acidified Foods – 1979– Infant Formula Quality Control
Procedures - 1982– Current Good Manufacturing Practice
- 1986
• Command and control– Pasteurized Milk Ordinance (PMO) –
1924– Low-Acid Canned Foods – 1973, 1979– Acidified Foods – 1979– Infant Formula Quality Control
Procedures - 1982– Current Good Manufacturing Practice
- 1986
New PhilosophyNew Philosophy• End results
–Preventative technologies–Food Safety Objectives
• End results–Preventative technologies–Food Safety Objectives
23
New PhilosophyNew Philosophy• Performance standards
–Focusing less on howoutcomes are achieve
–Focusing more on IS the outcome achieved • If the food safe?
• Performance standards–Focusing less on howoutcomes are achieve
–Focusing more on IS the outcome achieved • If the food safe?
New PhilosophyNew Philosophy• Creativity on the part of
the industry–Take risks in developing new
technologies–Providing the scientific rationale
and data for new processes• Importance of microbiological
testing
• Creativity on the part of the industry–Take risks in developing new
technologies–Providing the scientific rationale
and data for new processes• Importance of microbiological
testing
24
Change #2Changes in Knowledge
Change #2Changes in Knowledge
Changes in KnowledgeChanges in Knowledge
• Genetics• Genetics
25
Reference Strain Collection
History of Microbial IdentificationHistory of Microbial Identification• Detection at Genus Level• Detection at Genus Level
26
History of Microbial IdentificationHistory of Microbial Identification• Detection at Genus Level• Detection at Species Level• Detection at Genus Level• Detection at Species Level
History of Microbial IdentificationHistory of Microbial Identification• Detection at Genus Level• Detection at Species Level• Detection at Subspecies Level
• Detection at Genus Level• Detection at Species Level• Detection at Subspecies Level
27
History of Microbial IdentificationHistory of Microbial Identification• Detection at Genus Level• Detection at Species Level• Detection at Subspecies Level• Detection at Serotype or Serovar
Level
• Detection at Genus Level• Detection at Species Level• Detection at Subspecies Level• Detection at Serotype or Serovar
Level
History of Microbial IdentificationHistory of Microbial Identification• Detection at Genus Level• Detection at Species Level• Detection at Subspecies Level• Detection at Serotype or Serovar
Level• Detection at Molecular Level
• Detection at Genus Level• Detection at Species Level• Detection at Subspecies Level• Detection at Serotype or Serovar
Level• Detection at Molecular Level
28
Changes in KnowledgeChanges in Knowledge
• Genetics• Pathogenicity/Virulence
– Identification of virulence factors– Role of extrachromosomal elements
• Plasmids– What turns virulence genes “off” or
“on”• Quorum sensing
• Genetics• Pathogenicity/Virulence
– Identification of virulence factors– Role of extrachromosomal elements
• Plasmids– What turns virulence genes “off” or
“on”• Quorum sensing
Changes in KnowledgeChanges in Knowledge
• Genetics• Pathogenicity/Virulence• Ecology
• Genetics• Pathogenicity/Virulence• Ecology
29
Attachment and Survival of E. coli O157:H7 on Cut Lettuce
Attachment and Survival of E. coli O157:H7 on Cut Lettuce
Internalization of PathogensInternalization of Pathogens
30
31
Changes in KnowledgeChanges in Knowledge• Genetics• Pathogenicity/Virulence• Ecology• Growth and Survival in “Extreme”
Environments– Microbial adaptation and change
• Unrestricted use of antibiotics• Resistance to food processing technologies
– Acid, redox potential, sanitizer, preservative adaptation
• Genetics• Pathogenicity/Virulence• Ecology• Growth and Survival in “Extreme”
Environments– Microbial adaptation and change
• Unrestricted use of antibiotics• Resistance to food processing technologies
– Acid, redox potential, sanitizer, preservative adaptation
Changes in KnowledgeChanges in Knowledge• Genetics• Pathogenicity/Virulence• Ecology• Growth and Survival in “Extreme” Environments
• New Foodborne Pathogens• New, more virulent strains
– E. coli O157:H7, S. Typhimurium DT104, S.Enteritidis PT2
• Genetics• Pathogenicity/Virulence• Ecology• Growth and Survival in “Extreme” Environments
• New Foodborne Pathogens• New, more virulent strains
– E. coli O157:H7, S. Typhimurium DT104, S.Enteritidis PT2
32
Emergence of Foodborne Pathogens
Emergence of Foodborne Pathogens
• 1942– Staphylococcus aureus– Salmonella– Clostridium botulinum– Streptococci
• 1942– Staphylococcus aureus– Salmonella– Clostridium botulinum– Streptococci
33
Emergence of Foodborne Pathogens
Emergence of Foodborne Pathogens
– Yersinia enterocolita– Enterobacter sakazakii– Norwalk and Norwalk-
like viruses– Rotavirus– Cryptosporidium parvum– Giardia lamblia– Toxoplasma gondii– Bovine spongiform
encephalopathy prion
– Yersinia enterocolita– Enterobacter sakazakii– Norwalk and Norwalk-
like viruses– Rotavirus– Cryptosporidium parvum– Giardia lamblia– Toxoplasma gondii– Bovine spongiform
encephalopathy prion
– Campylobacter jejuni– Clostridium
botulinum (infant)– E. coli 0157:H7– Listeria
monocytogenes– Salmonella Enteritidis– Vibrio cholerae (Latin
America)– Vibrio vulnificus
– Campylobacter jejuni– Clostridium
botulinum (infant)– E. coli 0157:H7– Listeria
monocytogenes– Salmonella Enteritidis– Vibrio cholerae (Latin
America)– Vibrio vulnificus
New or Non-traditional Foods Associated With Recent
Outbreaks
New or Non-traditional Foods Associated With Recent
Outbreaks
• Mangos • Puffer fish • Almonds • Potatoes • Soft cheese• Mamey• Infant formula • Dry Cereal
• Mangos • Puffer fish • Almonds • Potatoes • Soft cheese• Mamey• Infant formula • Dry Cereal
• Seed/bean sprouts• Eggs• Salsa• Bean dip• Cantaloupe• Fruit juices• Berries
• Seed/bean sprouts• Eggs• Salsa• Bean dip• Cantaloupe• Fruit juices• Berries
34
Change #3Changes in Society
Change #3Changes in Society
Changes in SocietyChanges in Society
• Technology• Technology
35
Changes in SocietyChanges in Society
• Technology– Processing technology
• Aseptic • High pressure
– Transportation• Air freight• Refrigerated/MA trucking
– Packaging• Extended shelf-life
• Technology– Processing technology
• Aseptic • High pressure
– Transportation• Air freight• Refrigerated/MA trucking
– Packaging• Extended shelf-life
Changes in SocietyChanges in Society
• Technology• Human Demographics and Behavior• Technology• Human Demographics and Behavior
36
Changes in SocietyChanges in Society
• Technology• Human Demographics and Behavior
– Age– Increased reliance on medicines– Purchasing and eating habits– Migrations to urban centers
• Technology• Human Demographics and Behavior
– Age– Increased reliance on medicines– Purchasing and eating habits– Migrations to urban centers
Changes in SocietyChanges in Society
Consumers are eating different foods
Consumers are eating different foods
37
Changes in SocietyChanges in Society
20%-25% of the Population is At Risk
Changes in SocietyChanges in Society
More Food Prepared Outside the Home
38
Changes in the U.S. PopulationChanges in the U.S. Population
• 17% of population is 60 or older– 4% of the population is 80 or older
• 64% of the adult population is overweight
• 5% of infants and young children and 2% of adults have food allergies
• 44% of the non-institutionalized population reports taking one or more prescription medications during the last month
• 17% of population is 60 or older– 4% of the population is 80 or older
• 64% of the adult population is overweight
• 5% of infants and young children and 2% of adults have food allergies
• 44% of the non-institutionalized population reports taking one or more prescription medications during the last month
Changes in SocietyChanges in Society
• Technology• Demographics• Travel and Tourism
• Technology• Demographics• Travel and Tourism
39
Global TravelGlobal Travel
• International travel is a at an all time high and is expected to increase– Business– Tourism
• Travelers will be exposed to new types of organisms– E.g. Cyclosporiasis
• Once rare illnesses could become endemic in home country
• International travel is a at an all time high and is expected to increase– Business– Tourism
• Travelers will be exposed to new types of organisms– E.g. Cyclosporiasis
• Once rare illnesses could become endemic in home country
Forecast of Inbound Travel to U.S.Forecast of Inbound Travel to U.S.
36
38
40
42
44
46
48
2003 2004 2005 200636
38
40
42
44
46
48
2003 2004 2005 2006Travel Year
Arr
ival
s (m
illio
ns)
40
Changes in SocietyChanges in Society
• Technology• Demographics• Travel• Business
– International trade– Economic development and land use
• Consolidation of production and processing facilities
• Technology• Demographics• Travel• Business
– International trade– Economic development and land use
• Consolidation of production and processing facilities
Changes in SocietyChanges in Society
More Food Now Comes From Distant Places
More Food Now Comes From Distant Places
41
Imported Food Line EntriesImported Food Line EntriesFood Import Line Entries
02,000,0004,000,0006,000,0008,000,000
10,000,00012,000,00014,000,000
1990
1992
1994
1996
1998
2000
2002
2004
2006
*
Year*Estimates (2005 and 2006)
Changes in SocietyChanges in Society• Technology• Demographics• Travel• Business
– International trade– Economic development and land use
• Consolidation of production and processing facilities
• Technology• Demographics• Travel• Business
– International trade– Economic development and land use
• Consolidation of production and processing facilities
42
Future Trends Affecting the Regulatory Environment?
Future Trends Affecting the Regulatory Environment?
Future TrendsFuture Trends
• Enhanced role of epidemiology– Role of traditional microbiological
testing?
• Enhanced role of epidemiology– Role of traditional microbiological
testing?
43
Future TrendsFuture Trends
• Enhanced role of epidemiology• Better attribution
– Use of molecular biology to match outbreak strains to facility/line
– Identification of “hot” strains
• Enhanced role of epidemiology• Better attribution
– Use of molecular biology to match outbreak strains to facility/line
– Identification of “hot” strains
Future TrendsFuture Trends
• Enhanced role of epidemiology• Better attribution• Importance of International
Agreements– NAFTA-North America Free Trade
Agreement– GATT-General Agreements on Tariffs
and Trade• SPS-Sanitary and Phytosanitary
Measures Provisions
• Enhanced role of epidemiology• Better attribution• Importance of International
Agreements– NAFTA-North America Free Trade
Agreement– GATT-General Agreements on Tariffs
and Trade• SPS-Sanitary and Phytosanitary
Measures Provisions
44
• Harmonization– International Standards and
Regulations– Methods of Analysis– Codex Alimentarius Commission
• Standardizing body
• Harmonization– International Standards and
Regulations– Methods of Analysis– Codex Alimentarius Commission
• Standardizing body
Global TradeGlobal Trade
• Harmonization• Increased importance of International
Scientific Bodies– Joint Expert Committee on Food
Additives (JECFA)– Joint Expert Meetings on
Microbiological Risk Assessment (JEMRA)
• Harmonization• Increased importance of International
Scientific Bodies– Joint Expert Committee on Food
Additives (JECFA)– Joint Expert Meetings on
Microbiological Risk Assessment (JEMRA)
Global TradeGlobal Trade
45
SummarySummary• Microbiological Testing will Continue to
be a Fundamental Regulatory Tool• Scientific and Social Changes will
Impact the Role of Microbiological Testing– Changes in philosophy– Changes in knowledge– Changes in society
• Both Technology and the Regulatory Environment will change in response
• Microbiological Testing will Continue to be a Fundamental Regulatory Tool
• Scientific and Social Changes will Impact the Role of Microbiological Testing– Changes in philosophy– Changes in knowledge– Changes in society
• Both Technology and the Regulatory Environment will change in response