View
1.405
Download
4
Category
Tags:
Preview:
DESCRIPTION
Eastern PA Branch-ASM, 41st Annual Symposium, November 17, 2011
Citation preview
Nancy A. Strockbine, Ph.D.
Chief, Escherichia and Shigella Reference Unit
Enteric Diseases Laboratory Branch
Pathogenesis and Detection of Shiga toxin-
producing Escherichia coli ─
Food Safety Issues Related to E. coli O157
and non-O157 Strains
Division of Foodborne, Waterborne and Environmental Diseases
National Center for Emerging and Zoonotic Infectious Diseases
Presented at the Eastern Pennsylvania Branch-ASM 41st Annual Symposium
“Global Movement of Infectious Pathogens and Improved Laboratory Detection Methods”
Philadelphia, Pennsylvania
17 November 2011
Outline
• Pathogenesis
• Epidemiology and surveillance
• Detection
• Food safety
Terminology
• STEC – Escherichia coli that produce one or
more Shiga toxins
• EHEC– A subset of STEC that are capable of
causing diarrheal disease, including bloody
diarrhea and HUS
WHAT DO THEY CAUSE?
Clinical Presentation of STEC Disease in Humans
• Asymptomatic infection
• Nonbloody diarrhea
• Bloody diarrhea/hemorrhagic colitis
• Hemolytic uraemic syndrome (6-15%)
– Microangiopathic hemolytic anemia
– Thrombocytopenia
– Acute renal failure
• Chronic kidney failure in 25% of those with HUS
• Neurologic symptoms seen in TTP
Sequence of events in STEC infection
STEC O157 ingested
3 - 4 days
non-bloody diarrhea,
abdominal cramps (short lived fever)
5 - 6 days (up to 2-3
weeks) resolution
94%
bloody
diarrhea
1 - 2 days 80%
Non-O157 STEC ingested
3 - 4 days
5 - 6 days (up to 2-3
weeks) resolution
98%
bloody
diarrhea
1 - 2 days 45%
<2%
HUS HUS
non-bloody diarrhea,
abdominal cramps (short lived fever)
6-15%
E. coli Pathotypes
―Flexible Genome‖
• ~ 9,400 genes in pangenome
• ~ 2,200 genes in core
• Drivers of genetic diversity
– Phages
– Plasmids
– Pathogenicity Islands
~ 2,200
EPEC ETEC
UPEC/
NMEC
EAEC
EIEC/
Shigella
Commensal
4,238 – 5,589 genes per bacterial genome
Rasko, DA et al. J. Bacteriol. 2008
1030 phages equals mass of ~106 Blue Whales
106 Blue Whales end-to-end will circle over half the Earth’s
circumference
How big is 1030 ?
Shiga toxins
Phage encoded toxins
Act locally and systemically
Receptors on intestinal epithelium and kidney endothelium
Inhibit protein synthesis
binding of toxin to vascular tissue thought to trigger coagulation
cascade
Two subgroups (Stx1 and Stx2)
Strains that produce Stx2 are more virulent
Necessary but not sufficient to cause disease
Other virulence factors involved
O’Brien AD et al. Science 226:694-696, 1984.
Potential Virulence Genes
Gene or plasmid Predicted product or phenotype
stx1 Shiga toxin 1
stx2 Shiga toxin 2
eae intimin
EHEC-hlyA (ehxA) EHEC hemolysin (enterohemolysin)
espP serine protease
katP catalase
cdt cytolethal distending toxin
efa-1 EHEC factor of adherence (Efa1)
saa STEC autoagglutinating adhesin (Saa)
iha IrgA homologue adhesin (Iha)
lfpA Major fimbrial subunit of LPF (Long polar Fimbriae)
ent/espL2, nleB, nleE, nleF,
nleH1-2, nleA
genes from genomic islands OI-122 and OI-71
irp-2 Iron-repressible protein 2
fyuA Yersiniabactin receptor
Virulence profile and clinical manifestation in
559 Danish STEC patients 1994-2005
0%
20%
40%
60%
80%
100%
stx2 +
eae
stx1 +
stx2 +
eae
stx1 +
eae
stx2 stx1 +
stx2
stx1
Other
D
PD
BD
PBD
HUS
Courtesy Flemming Scheutz, WHO Collaborating Center for Escherichia and Klebsiella, SSI
Stx1 : 4 subtypes a - d
7-8 variants
d
b
c
a Stx1a-S._dysenteriae-3818T
Stx1a-S._sonnei-CB7888
Stx1b-O111-CB168
Stx1b-O157-EDL933
Stx1b-O48-94C
Stx1b-O111-PH
Stx1c-O174-DG131-3
Stx1d-ONT-MHI813
Pairwise (OG:100%,UG:0%) (FAST:2,10) Gapcost:0%
VT1 translated sequences
100
99
98
97
96
Courtesy Flemming Scheutz, WHO Collaborating Center for Escherichia and Klebsiella, SSI
Pairwise (OG:100%,UG:0%) (FAST:2,10) Gapcost:0% Disc. unk.
vtx_TRANSL
100
999897969594939291908988878685848382vtx2d-O157-7279
vtx2d-O174-EC1720a
vtx2d-O91-a-B2F1
vtx2d-O91-b-B2F1
vtx2d-O8-C466-01B
vtx2d-C_freundii-LM76..
vtx2d-O6-NV206
vtx2d-O22-KY-O19
vtx2d-O73-C165-02
vtx2a-O157-EDL933
vtx2a-O26-FD930
vtx2a-O157-SF
vtx2a-O48-94C
vtx2a-O26-126814
vtx2a-E_cloacae-95MV2
vtx2c-O157-E32511
vtx2c-O157-FLY16
vtx2c-O157-C394-03
vtx2c-O157-469
vtx2c-O174-b-031
vtx2g-O2-7v
vtx2g-O2-S86
vtx2g-Out-S-8
vtx2b-O111-S-3
vtx2b-O96-S-6
vtx2b-O22-3143-97
vtx2b-ONT-5293-98
vtx2b-O118-EH250
vtx2b-O16-6451-98
vtx2b-O174-a-031
vtx2b-O111-PH
vtx2e-O139-412
vtx2e-O22-3615-99
vtx2e-O101-E-D43
vtx2f-O128-T4-97
d
f
b
g
c
a
e
Stx2 :
7 subtypes
a - g
35 variants
Courtesy Flemming Scheutz, WHO Collaborating Center for Escherichia and Klebsiella, SSI
Subtype Non-HUS * HUS*
stx2a 60 11
stx2c 49 1
stx2d-activatable 4
stx2d 39
stx2e 2
stx2-variant 3
stx2 + stx2c 23 7
stx2 + stx2d 1
2x stx2-activatable 4
stx2c + stx2-activatable 1
Total 186 19
Ethelberg et al. 2004 EID: vol 10
Shiga toxin 2 (stx2) subtype and clinical presentation
stx2 OR* 32.5 > stx2c OR* 4.7 for HUS *) OR: odds ratio; multivariant analysis adjusted for age
Courtesy Flemming Scheutz, WHO Collaborating Center for Escherichia and Klebsiella, SSI
Bacteriophages replicate, toxin production is amplified, cells lyse and release Shiga toxin and phage progeny
Lytic cycle
Phage DNA integrates into host chromosome
Lysogenic cycle
Electron micrographs by R. Hendrix
Slide courtesy Louise Teel, USUHS
Lifestyle options of Shiga toxin-converting
bacteriophages
RecA
• Damage to the host cell DNA triggers the SOS response
• Expression of the bacterial RecA protein is up-regulated
• RecA cleaves the phage repressor of the lytic cycle
• Downstream genes, including the toxin genes, get transcribed
X
att int xis cIII N cI cro cII O P Q stxA/B S R Rz head genes tail genes
C1 repressor
Basic lambda genome structure… …toxin genes here
Induction of expression of the late gene
cluster of lambdoid phages
Slide courtesy Louise Teel, USUHS
Norfloxacin-induced Stx phage being released
from a bacterium
Allison, HE Future Microbiol. 2:165-174, 2007
Escherichia coli O104:H4 Outbreak in Germany, May 2011
Proposed scheme for the origin of a new E. coli pathotype--
Enteroaggregative hemorrhagic Escherichia coli
Brzuszkiewicz E. et al. Arch Microbiol. 2011
HOW COMMON ARE NON-O157 STEC?
Surveillance systems
National surveillance: passive
National Notifiable Disease Surveillance System
Public Health Laboratory Information System
CDC National E. coli Reference Laboratory
PulseNet
Sentinel surveillance: active
Foodborne Disease Active Surveillance Network (FoodNet)
FoodNet 10 sites , 46 million persons (15% of US population)
0
0.5
1
1.5
2
2.5
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
STEC O157 Non-O157 STEC
Incidence of reported STEC O157 and non-O157 STEC infections, by year, FoodNet, 1996-2009
Year
Ca
ses
pe
r 1
00
,00
0 p
op
ula
tio
n
Healthy People 2010 objective is 1 case/100,000 persons
0
0.5
1
1.5
2
2.5
3
CA CO CT GA MD MN NM NY OR TN Overall 2009
STEC** O157
STEC non-O157
Incidence of O157 STEC and non-O157 STEC
Cases at FoodNet Sites, 2009
Nu
mb
er o
f ca
ses/
10
0,0
00
po
pu
lati
on
Burden of Illness
Surveillance detects the tip of the iceberg
Detecting an illness depends on probability of… ill person seeking medical care
stool sample requested
stool sample received
necessary tests performed
test result positive
infection reported
0 200,000 400,000 600,000 800,000 1,000,000 1,200,000
Clostridium botulinum, foodborne
Mycobacterium bovis
Vibrio cholerae, toxigenic
V. vulnificus
Brucella spp.
Listeria monocytogenes
S. enterica serotype Typhi
Streptococcus spp. group A, foodborne
Other diarrheagenic E. coli
Vibrio spp., other
ETEC, foodborne
V. parahaemolyticus
STEC O157
Bacillus cereus, foodborne
Yersinia enterocolitica
STEC non-O157
Shigella spp.
Staphylococcus aureus, foodborne
Campylobacter spp.
Clostridium perfringens, foodborne
Salmonella spp., nontyphoidal
Proportion of Annual Foodborne Illness in the
United States by Pathogen
Scallan et al. 2011 EID 17(1)7-15
Number of illnesses
0 10 20 30 40 50 60 70 80 90 100
Streptococcus spp. group A, foodborne
Bacillus cereus, foodborne
Clostridium perfringens, foodborne
ETEC, foodborne
Other diarrheagenic E. coli
Staphylococcus aureus, foodborne
STEC non-O157
Campylobacter spp.
Shigella spp.
V. parahaemolyticus
Salmonella spp., nontyphoidal
Yersinia enterocolitica
Vibrio spp., other
Vibrio cholerae, toxigenic
STEC O157
Brucella spp.
Mycobacterium bovis
S. enterica serotype Typhi
Clostridium botulinum, foodborne
V. vulnificus
Listeria monocytogenes
Hospitalization rate, %
Scallan et al. 2011 EID 17(1)7-15
0 5 10 15 20 25 30 35 40
Bacillus cereus, foodborne
ETEC, foodborne
Other diarrheagenic E. coli
S. enterica serotype Typhi
Streptococcus spp. group A, foodborne
Vibrio cholerae, toxigenic
Campylobacter spp.
Clostridium perfringens, foodborne
Shigella spp.
Staphylococcus aureus, foodborne
STEC non-O157
STEC O157
Salmonella spp., nontyphoidal
Brucella spp.
V. parahaemolyticus
Yersinia enterocolitica
Vibrio spp., other
Mycobacterium bovis
Listeria monocytogenes
Clostridium botulinum, foodborne
V. vulnificus
Death Rate, %
Scallan et al. 2011 EID 17(1)7-15
E. coli O157:H7 Gel
BioNumerics Server
BNServer
with database
Client
Client
• Upload & download of information
• Internet based
Shiga toxin gene distribution among 19,402
STEC from the US, 2006-2010 by Serogroup
No
. is
ola
tes
fro
m P
uls
eNet
an
d C
DC
Ref
La
b
Serogroup * Includes 120 O groups
Prevalence of STEC Serogroups in the US
from 2006-2010 n = 19,402
0
500
1000
1500
2000
2500
3000
3500
4000
4500
2006 2007 2008 2009 2010
O157
O26
O103
O111
O45
O121
O145
Other*Total
No
. is
ola
tes
fro
m P
uls
eNet
an
d C
DC
Ref
La
b
year * Includes 120 O groups
= 501-750 isolates
= 1-250 isolates
= 251-500 isolates
= 751-1000 isolates
= > 1001 isolates
Geographic Distribution of 1342 STEC O157
isolates from 2006-2010
= 61-90 isolates
= none reported
= 1-30 isolates
= 31-60 isolates
= 91-120 isolates
= > 121 isolates
Geographic Distribution of 1342 STEC O26
isolates from 2006-2010
= 50--75 isolates
= none reported
= 1-25 isolates
= 26--50 isolates
= 75-100 isolates
= > 101 isolates
Geographic Distribution of 1116 STEC O103
isolates from 2006-2010
= 50--75 isolates
= none reported
= 1-25 isolates
= 26--50 isolates
= 75-100 isolates
= > 101 isolates
Geographic Distribution of 985 STEC O111
isolates from 2006-2010
= 21-30 isolates
= none reported
= 1-10 isolates
= 11-20 isolates
= 31-40 isolates
= 41-50 isolates
Geographic Distribution of 348 STEC O45
isolates from 2006-2010
= 21-30 isolates
= none reported
= 1-10 isolates
= 11-20 isolates
= 31-40 isolates
= 41-50 isolates
Geographic Distribution of 277 STEC O121
isolates from 2006-2010
= 21-30 isolates
= none reported
= 1-10 isolates
= 11-20 isolates
= 31-40 isolates
= 41-50 isolates
Geographic Distribution of 253 STEC O145
isolates from 2006-2010
HOW ARE STEC TRANSMITTED?
Key factors in STEC transmission
Reservoir is the intestinal tract of animals
Especially cattle
Very low infectious dose
<100 organisms
Multiple modes of transmission
Foodborne
Animal contact
Waterborne
Person-to-person contact
Most infections are not outbreak-related
~19% of E. coli O157 infections, ~9% of non-O157 STEC infections
Proportion of illnesses by mode of transmission in
344 STEC O157 outbreaks, 1998-2007
Mode of transmission
Illnesses in outbreaks
(n=7,864 illnesses)
%
Foodborne 69
Waterborne 18
Animals or their environment 8
Person-to-person 6
Non-O157 STEC outbreaks: modes of
Transmission—United States, 1990-2008
Mode of transmission
Non-
O157
No.
Non-
O157
%
Foodborne 9 33
Person-to-person 7 26
Water 4 15
Animal contact 4 15
Mixed modes 1 4
Unknown 2 7
Total 27 100
Outbreak of STEC O145 Infections May 2010
33 cases in 5 states
Michigan, New York, Ohio, Pennsylvania, and Tennessee
First recognized multistate outbreak of non-O157 STEC
40% hospitalized, 10% developed HUS
As severe as illness caused by E. coli O157:H7
Caused by contaminated Romaine lettuce
Exposures associated with sporadic non-O157 STEC infections
Australia
Corned beef, camping, occupational contact with animals
Germany
Children: touching a ruminant, playing in a sandbox
Adults: eating lamb and spreadable sausage
United States
Minnesota: recent international travel?
FoodNet: study under development
HOW SHOULD LABS DETECT STEC?
Clinical laboratory recommendations, 2009
Simultaneously culture all stools
submitted from patients with
acute community-acquired
diarrhea or suspected HUS for
O157 and assay for non-O157
STEC with a test that detects Shiga
toxin
Report and send E. coli O157
isolates and Stx+ broths to a public
health laboratory as soon as
possible
Why test all stool samples for STEC?
Selective testing practices miss many STEC infections
Children
• Over half of infections occur in older adolescents and adults
• Highest mortality rate in persons ≥60 years old
Summer months
• ~50% of infections occur in non-summer months
• Outbreaks can occur year round
Bloody diarrhea
• Some patients do not have bloody diarrhea
STEC might be detected as often as other bacterial
enteric pathogens
Why simultaneously culture for E. coli O157 and assay for Shiga toxin?
Most sensitive approach to detect all STEC infections
Rapidly distinguishes O157 from non-O157 STEC infections
Isolates are obtained in a timely manner
Proposed best practice benefits patient care and public health
Patient care
Facilitates early clinical management decisions to reduce risk of HUS
• Avoidance of antibiotics and anti-diarrheals
Early identification of E. coli O157 can further influence management
decisions
Avoidance of unnecessary procedures
Public health
Allows for prompt confirmation and subtyping by public health labs
to detect and control of outbreaks
Allows for monitoring of epidemiological trends
Clinical Diagnosis of STEC infection Stool
Specimen
Enrichment broth Shiga toxin or stx gene
detection
16-24
hours
Send STEC O157 and
positive broths to public
health lab
Culture
for O157
STEC
Streak to
Selective/differential
agar Culture for
non-O157
STEC
Test in
O157 latex
reagent
Test
• Shiga toxin
or H7
• ID as E. coli
Stx/stx+ broth Enrichment broth
16-24
hours
Enrichment broth
16-24
hours
Enrichment broth
16-24
hours
Enrichment broth
16-24
hours
Enrichment broth
16-24
hours
Enrichment broth
16-24
hours
Enrichment broth
16-24
hours
Enrichment broth
16-24
hours
Enrichment broth
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Enrichment broth
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Enrichment broth
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Enrichment broth
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Enrichment broth
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Enrichment broth
Culture
for O157
STEC
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Enrichment broth
Culture
for O157
STEC
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Enrichment broth
Stool
Specimen
Culture
for O157
STEC
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Enrichment broth
Culture for
non-O157
STEC
Stool
Specimen
Culture
for O157
STEC
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Enrichment broth
Culture for
non-O157
STEC
Stool
Specimen
Culture
for O157
STEC
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Enrichment broth
Streak to
Selective/differential
agar Culture for
non-O157
STEC
Stool
Specimen
Culture
for O157
STEC
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Test in
O157 latex
reagent
Streak to
Selective/differential
agar Culture for
non-O157
STEC
Stool
Specimen
Culture
for O157
STEC
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Shiga toxin or stx gene
detection
Test in
O157 latex
reagent
Streak to
Selective/differential
agar Culture for
non-O157
STEC
Stool
Specimen
Culture
for O157
STEC
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Stx/stx+ broth
Shiga toxin or stx gene
detection
Test in
O157 latex
reagent
Streak to
Selective/differential
agar
Stool
Specimen
Culture
for O157
STEC
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Test
• Shiga toxin
or H7
• ID as E. coli
Send STEC O157 and
positive broths to public
health lab
16-24
hours
Isolation of STEC from Stx-positive broths by PHLs
Selective plate: CT-SMAC or CHROM O157
Nonselective plate: SMAC or WSBM
Screen suspect colonies in O157 latex reagent
Sweep of Growth
Shiga toxin assay or PCR for stx1, stx2
Isolated colonies (or pool 5 colonies)
IF NEGATIVE
or
Shiga toxin-positive broth
SMAC or WSBM
Serogrouping and PFGE
•Detects E. coli O104
• Available in Europe;
not yet in the US
•Tests for 15 bacteria,
viruses and parasites in
under 5 hours
Seeplex® System
Seeplex® is a breakthrough multiplexing PCR technology that enables a new standard in simultaneous multi-
pathogen detection. Seegene applies its novel and proprietary Seeplex® system utilizing its DPO™ (Dual Priming
Oligonucleotide) technology to create multi-pathogen tests delivering maximum specificity, reproducibility and
sensitivity.
DPO™ Technology
DPO™ technology is a fundamental tool for blocking extension of non-specifically primed templates generating
consistently high specificity. The strength and utility of this DPO™ technology can be successfully incorporated
into molecular diagnostics systems such as multiplex diagnostics and SNP genotyping systems.
Seeplex® System
Seeplex® is a breakthrough multiplexing PCR technology that enables a new standard in simultaneous multi-
pathogen detection. Seegene applies its novel and proprietary Seeplex® system utilizing its DPO™ (Dual Priming
Oligonucleotide) technology to create multi-pathogen tests delivering maximum specificity, reproducibility and
sensitivity.
DPO™ Technology
DPO™ technology is a fundamental tool for blocking extension of non-specifically primed templates generating
consistently high specificity. The strength and utility of this DPO™ technology can be successfully incorporated into
molecular diagnostics systems such as multiplex diagnostics and SNP genotyping systems.
Seeplex® System
Seeplex® is a breakthrough multiplexing PCR technology that enables a new standard in simultaneous multi-
pathogen detection. Seegene applies its novel and proprietary Seeplex® system utilizing its DPO™ (Dual Priming
Oligonucleotide) technology to create multi-pathogen tests delivering maximum specificity, reproducibility and
sensitivity.
DPO™ Technology
DPO™ technology is a fundamental tool for blocking extension of non-specifically primed templates generating
consistently high specificity. The strength and utility of this DPO™ technology can be successfully incorporated into
molecular diagnostics systems such as multiplex diagnostics and SNP genotyping systems.
C | Diarrhea-B2 ACE Detection
Y.enterocolitica
1~7: Clinical
samples
7
E.coli : O157
E.coli : H7
VTEC 6
E.coli : O157
E.coli : H7 5
E.coli : H7 4
Aeromonas spp. 3
C. perfringens 2
Aeromonas spp. 1
C | Diarrhea-B2 ACE Detection
Y.enterocolitica
1~7: Clinical
samples
7
E.coli : O157
E.coli : H7
VTEC 6
E.coli : O157
E.coli : H7 5
E.coli : H7 4
Aeromonas spp. 3
C. perfringens 2
Aeromonas spp. 1
C | Diarrhea-B2 ACE Detection C | Diarrhea-B2 ACE Detection
E.coli : O157
E.coli : H7
C | Diarrhea-B2 ACE Detection
Seegene Diarrhea ACE Detection for Stool 1 Viral and 2 Bacterial Panels (14 Agents in 6 hr)
C | Diarrhea-B2 ACE Detection
Y.enterocolitica
1~7: Clinical
samples
7
E.coli : O157
E.coli : H7
VTEC 6
E.coli : O157
E.coli : H7 5
E.coli : H7 4
Aeromonas spp. 3
C. perfringens 2
Aeromonas spp. 1
C | Diarrhea-B2 ACE Detection
Y.enterocolitica
1~7: Clinical
samples
7
E.coli : O157
E.coli : H7
VTEC 6
E.coli : O157
E.coli : H7 5
E.coli : H7 4
Aeromonas spp. 3
C. perfringens 2
Aeromonas spp. 1
C | Diarrhea-B2 ACE Detection C | Diarrhea-B2 ACE Detection
E.coli : O157
E.coli : H7
C | Diarrhea-B2 ACE Detection
Detection of STEC in Foods http://www.fsis.usda.gov/PDF/MLG_5B_00.pdf
Sample enrichment
Genomic DNA extraction
TaqMan-based multiplex real-time PCR assay:
stx1, stx1, eae (intimin) and 16S rRNA
O-antigen identification (real-time PCR)
Immunomagnetic separation
Selective plating
If positive
confirmation
Food Safety
• September 20, 2011 FSIS announced six STEC serogroups
(O26, O45, O103, O111, O121 and O145) will be adulterants
on raw, non-intact beef products in the same manner as
E. coli O157:H7
• FSIS will apply its adulteration decision when testing is
initiated March 5, 2012
Summary
STEC can cause non-bloody or bloody diarrhea and HUS
Horizontal gene transfer is common -- phage play an important role
Prevalence varies geographically
Primary reservoir ruminants, especially cattle
Simultaneous culture for E. coli O157:H7 and an assay that detects Stx or stx genes is the most sensitive approach for all STEC
STEC O26, O45, O103, O111, O121 and O145 FSIS will be regulated by FSIS like E. coli O157:H7 starting March 2012
Nancy A. Strockbine, Ph.D. Chief, Escherichia and Shigella Reference Unit
Enteric Diseases Laboratory Branch
Division of Foodborne, Waterborne and Environmental Diseases
National Center for Emerging and Zoonotic Infectious Diseases
Centers for Disease Control and Prevention
Phone: (404) 639-4186
FAX: (404) 639-3333
E-mail: Nancy.Strockbine@cdc.hhs.gov
Pathogenesis and Detection of Shiga toxin-producing Escherichia coli ─
Food Safety Issues Related to E. coli O157
and non-O157 Strains
Enteric Diseases Laboratory Branch
The findings and conclusions in this report are those of the author and do not necessarily
represent the official position of the Centers for Disease Control and Prevention.
National Enteric
Reference Laboratory
Team Patricia Fields, Ph.D.
12 FTE, 8 non-FTE
Escherichia and Shigella,
Unit
Nancy Strockbine, Ph.D.
Salmonella Unit
Patricia Fields, Ph.D.
Campylobacter and
Helicobacter Unit
Collette Fitzgerald, Ph.D.
National Botulism
Laboratory
Preparedness Team Susan Maslanka, Ph.D.
5 FTE, 3 non-FTE
NARMS Surveillance
Unit
Kevin Joyce
NARMS Applied
Research Unit
Jean Whichard, D.V.M., Ph.D.
Listeria ,Yersinia , Vibrio
and other
Enterobacteriaceae Unit
Cheryl Tarr, Ph.D.
PulseNet Database Unit Kelley Hise, M.P.H.
PulseNet Methods Development and
Reference Unit Efrain Ribot, Ph.D.
Epidemic Investigations
Laboratory Unit Cheryl Bopp, M.S.
Immunodiagnostics Unit
Deborah Talkington, Ph.D.
Enteric Diseases Laboratory Branch Peter Gerner-Smidt, M.D., D.M.S., Branch Chief
John Besser, Ph.D., Deputy Branch Chief
Sherricka Simington, Branch manager
Nicole Rankine, QMS manager
4 FTE, 2 non-FTE
National Antimicrobial
Resistance Surveillance
Team Jean Whichard, D.V.M., Ph.D.
4 FTE, 5 non-FTE
National Enteric
Laboratory Diagnostics
and Outbreak Team Deborah Talkington, Ph.D.
7 FTE, 1 non-FTE
PulseNet USA Team
Efrain Ribot, Ph.D.
13 FTE, 7 non-FTE
Botulism Public Health
Research Unit
Brian Raphael, Ph.D.
Botulism Outbreak
Investigation Unit
Carolina Luquéz, Ph.D.
2-1-2010
Recommended