The 3 musketeers of food borne infections
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The 3 musketeers of food borne infections:
Salmonella, Campylobacter and
Shiga toxin producing Escherichia coli
Prof. dr. ir. Mieke Uyttendaele
Lab of Food Microbiology and Food Preservation
Dept. Food Safety & Food Quality
Faculty of Bio-Science Engineering
Ghent University, Belgium
www.foodscience.ugent.be/LFMFP
www.itpfoodsafety.ugent.be www.UGent.be
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
The 3 musketeers… or was it 4 of them?
Escherichia coli
Salmonella
Campylobacter jejuni Listeria monocytogenes
Athos, Porthos, Aramis
friends of d’Artagnan De “big four” in food safety
(central character in book by Alexandre Dumas)
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.be
Salmonella, STEC, Campylobacter : zoonotic pathogens need a farm to fork approach. They may persist in the animal reservoir and spread to other sources, the origin of food borne transmission to human.
Salmonella
vs
Campylobacter
vs
STEC
- History
- Taxonomy, reservoirs, associated foods
- Legislation, action limits
- Detection methods
- Growth and survival
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.be
History of Salmonella 1885: discovery of the Salmonella cholerae suis, causing “swine plague” by Theobald Smith, Salmon's research assistant at Veterinary Division of USDA 1888: outbreak of gastroenteritis in humans associated with red meat 1926-1936: Kauffmann-White Scheme for serotyping (based on O & H antigen) Interreg III “Beheers de voedselketen” slotconferentie Turnhout, 13 december 2007 Belang van voedselveiligheid in de keten Prof. M. Uyttendaele
History of Campylobacter 1913: Vibrio-like bacteria in foetal tissue of aborted sheep 1940s: Vibrio fetus, Vibrio jejuni, Vibrio coli 1963: the genus Campylobacter 1970s: isolation method optimized by Butzler, first isolation from stool samples of patients with diarrhea 1980s: new campylobacters identified and Campylobacter recognized as most frequent cause of human bacterial enteritis 1991: Vandamme et al. : Revision of Campylobacter, Helicobacter, and Wolinella Taxonomy: Emendation of Generic Descriptions and Proposal of Arcobacter gen. nov.". Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl Mieke Uyttendaele www.foodmicrobiology.UGent.be
History of Shiga-toxin producing E. coli 1885: the German-Austrian pediatrician Theodor Escherich discovered it in the feces of healthy individuals and called it Bacterium coli commune because it is found in the colon 1982: two hemorrhagic colitis outbreaks in US with STEC O157 due to undercooked hamburgers 1996: , radish sprouts were associated with the largest recorded outbreak of E. coli O157:H7 in Japan associated with radish sprouts (6000 cases) 2003: Karmali et al. & the seropathotype approach O157, O26, O103, O145, O111 2011: E. coli O104:H4 outbreak in Germany with fenugreek seeds (3968 ill, 900, HUS, 55 died)
EFSA report on Trends & Sources of Zoonoses,
Zoonotic Agents and Food borne outbreaks in 2013
Salm: 85,268 vs Campy: 214,779 vs VTEC: 6112 cases
Food
borne
outbreaks
Interreg III “Beheers de voedselketen” slotconferentie Turnhout, 13 december 2007
published in van
Belang 2015voedselveiligheid in de keten Prof. M. Uyttendaele
Salmonella
vs
Campylobacter
vs
STEC
- History
- Taxonomy, reservoirs, associated
foods
- Legislation, action limits
- Detection methods
- Growth and survival
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.be
Salmonella enterica subsp. enterica
• Family Enterobacteriaceae
• Rod-shaped, motile
Intestinal tract of (farm) animals (and also
Salmonella reptiles and amphibians and rodents!)
• Mostly associated with eggs/bakery and meat (pork / poultry)
• Increasingly reported in low water activity foods, foods of non
animal origin (leafy greens, herbs, melons, tomatoes)
• Gastroenteritis (diarrhea, fever, nausea and abdominal
cramps; may lead to hospitalization of young/old)
• Infective dose: 10-106
• More than 2500 serotypes
Top 5 serotypes in EU targeted in animal production (farm): S.
Enteritidis, S. Infantis, S. Hadar, S. Typhimurium, S. VirchowMicrobiological criteria
EU Reg. 2073/2005
ITP Food Safety Prof. Mieke Uyttendaele - 7 sept. 2009 Ghent UniversitySalmonella enterica subsp. enterica
2000 serotypes
e.g. S. Panama (melons, US 2011 – fresh juices US 2008)
e.g. S. Hadar (turkey burger, US 2010-2011)
e.g. S Bareilly (soy sprouts, UK 2010)
e.g. S. Typhimurium (beef, France, 2010 - pork Denmark 2008 –
Peanut Butter, US 2008)
e.g. S. Braenderup (pastueriz. Milk, US 2010)
e.g. S. Hvittingfoss (fresh vegetables, US 2010)
e.g. S. Mbandaka (eggs, Austria 2010)
e.g. S. Montevideo (pepper salami, US 2009-2010)
e.g. S. Enteritidis (fresh cheese and cheddar, Canada 2008)
e.g. S Kedougou (baby food, Spain 2008)
e.g. S. Saintpaul (Jalapeno & serrano peppers, US 2008)
e.g. S. agona (puffed rice & wheat, US 2008)
ITP Food Safety Prof. Mieke Uyttendaele - 7 sept. 2009 Ghent UniversityCampylobacter jejuni/coli
• Family Campylobacteriaceae
• Gram negative, small, spiral-
shaped
Salmonella • Intestinal tract of broilers
(and also wild birds / rodents !)
• Mostly associated with poultry meat
but also water borne !
• Enteritis (abdominal cramps, diarrhea, fever and
Guillan-Barré syndrome, reactive arthritis,
irritable bowel syndrome)
• Infective dose: 500-106
• Large genetic diversity (MLST typing), frequent
recombination (response to selective pressure)Biosecurity on the farm
an anteroom with hygiene barrier
(with adequate boot dips and hand wash facilities)
a rodent-free and concrete hard surround with no standing water
Potable water supply or treated well water
the exclusion of pets and control of visitors
additional measures as examples
‣ The use of house-specific footwear and clothing,
‣ Provision of dedicated changing facilities
www.camcon-eu.net
‣ External training for farm managers
‣ Under investigation : the introduction of fly screens for houses
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beCampylobacter uit kippen main
reservoir
Baseline studies !
Interreg III “Beheers de voedselketen” slotconferentie Turnhout,
Sampers 13etdecember 2007
al. - Habib et al
Belang van voedselveiligheid in de keten Seliwiorstow
Prof.et
M.al. - Duarte et al.
UyttendaeleCampylobacter carcass contamination throughout the
slaughter process of Campylobacter-positive broiler batches
Main findings
• High within batch and between batches variability in Campylobacter carcass contamination
• Number of carcasses after chilling contaminated ≥1000 cfu/g differed between plants
• Control of external contamination of broilers entering the slaughter process may result in
lower carcass contamination
• Plucking, evisceration, washing and chilling influence Campylobacter counts on carcasses
Slaughterhouse Percentage of highly
contaminated carcasses
(≥3 log cfu/g) after chilling
A 47
B 40
C 78
D 23
E 20
F 40
16
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beIt is all about the numbers !
Frequency
400
48.02% (315/656)
of the Belgian chicken meat
350
preparations (CMP) samples tested
positive for C. jejuni/ coli
300
Action limit of 100 cfu/g CMP in Be
250
29.4%
200
≥ 10 to < 11.63%
≥ 100
150
100 CFU/g
100
50 CFU/g
Action limit of
0
1000 cfu/g neck 0.5 1 1.5 2 2.5 3 3.5 4 4.5
skin in UK / Be / Nl Campylobacter count (log10 CFU/g)
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beIt is not all about poultry ! EFSA opinion on raw milk in 2015 Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl Mieke Uyttendaele www.foodmicrobiology.UGent.be
Shiga-toxin producing E. coli (STEC)
• Family Enterobacteriaceae
• Gram negative, rod-shaped
E. coli
• Intestinal tract of humans & animals advantageous
(e.g. digestion, production of vitamins)
• But some acquired DNA pathogenic (e.g. Shiga toxin-
producing Escherichia coli (STEC))
• Mostly associated with bovine meat
• But also raw milk & derived dairy products
• Also sprouted seeds / leafy greens
• Gastroenteritis, hemorrhagic colitis and
hemolytic uremic syndrome (HUS)possible
Infective dose: 10-100 cells !EHEC outbreak in Germany/France in May/July
2011 - STEC in fresh produce ?
Not cucumbers
from Spain but
Fenugreek seed
from Egypt
EFSA Scientific Opinion in 2011 on risk posed by Shiga toxin-producing Escherichia
coli (STEC) and other pathogenic bacteria in seeds and sprouted seeds
EFSA Scientific Opinion in 2013 on VTEC Seropathotype and scientific criteria regarding
pathogenicity assessment.
EFSA Scientific Opinion in 2013-2014 on the risk posed by pathogens in food of non-
animal origin. Part 1-5
ISO/TS 13136:2012(E). Horizontal method for the detection STEC and the determination
of O157, O111, O26, O103 and O145 serogroups.
EC Traceability & certification requirements, approval of establishments of sprouts/seeds
Food Safety criteria in EC 2073/2005 for sprouts:
n= 5 c= 0 absence/25g Salmonella & (STEC) O157, O26, O111, O103, O145 and O104
EC Training for Safer Food : “good practices in the fresh produce supply chain”
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beSTEC but also Salmonella & even Campylobacter in
fresh produce: contamination via water, soil, wild life ?
Spinach-associated Jalapenos peppers
Escherichia coli O157:H7 Salmonella Saintpaul ,
Outbreak in US (2006). The US (2008) The outbreak
river functioned as a vector strain was isolated from
between the contaminated two environmental samples, agricultural
feces and the irrigation wells water, and Serrano peppers on a farm in
Mexico growing peppers
Alaska, US (2008) raw peas fecal contaminated
with Campylobacter by wild birds (Sandhill cranes)
(established by MLST typing)
Sweden (2005) iceberg lettuce and E. coli Australia (2006): papayas and
O157: irrigated by water from a small stream Salmonella Litchfield : washed
& cattle at a farm upstream from the with water from a source later
irrigation point determined to contain other
serotypes of Salmonella
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beTwo STEC outbreaks
in Belgium
STEC uit runderen als main reservoir
Ook uitbraken In dairy
In foods of non animal origin
Schema van STEC ?
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.benon RTE food
appropriate
treatment to
reduce STEC
RTE food /
non RTE food
treatment
insufficientThe preventive approach(QA) and control of
Salmonella , STEC, Campylobacter
Product specific preventive measures
- GAP: Good Agricultural Practices at primary production
- Good Slaughtering practices
- Processing industry : implementation of Pre-Requisite
Programs (GMP) and HACCP
verification by indicator testing ?
E. coli: indicator of fecal contamination
Elevated numbers of E. coli relate to higher likelihood of
finding enteric pathogens BUT predictive value is moderate
good practices ≠ pathogen finding !
Or rather have actual pathogen testing in place ?
Sampling plans (always) have limitations for ensuring safety
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beSalmonella
vs
Campylobacter
vs
STEC
- History
- Taxonomy, reservoirs, associated foods
- Legislation, action limits
- Detection methods
- Growth and survival
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beDetection methods
Molecular detection
Classical culture methods STEC: ISO 13136:2012
Salmonella : ISO 6579:2002
DNA
PCR
Campylobacter :
ISO 10272:
2006
look for suspected colonies,
for further confirmationSalmonella
vs
Campylobacter
vs
STEC
- History
- Taxonomy, reservoirs, associated foods
- Legislation, action limits
- Detection methods
- Growth and survival
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beGrowth* & survival of
Salmonella, STEC, Campylobacter
Tmin pHmin Awm Dx°C(min)
Salmonella 7-8°C 4.4 0.95 D60 0.5
Camp. 32°C 4.9 0.99 D55 1.50
Jejuni* *microaerophilic (5% O2-10%CO2-85%N2)
E. coli 7-8°C 4.4 0.95 D60 0.46
Yers. enter. -1,3°C 4.5 0.96 D58 1.6
L. monoc. 0°C 4.4 0.92 D60 2.50
*Modified from ICMSF 5Growth & survival of Salmonella, STEC,
Campylobacter
cold chain
Salmonella - E. coli / STEC -Campylobacter
growth inhibition SURVIVAL ! (humid conditions for Campy !)
growth upon temperature abuse (10°C or for Campy > 30°C)
frozen storage
in particular susceptible to damage
sublethal injury provoking gradual inactivation
Campylobacter susceptible to freezing : control strategy !
packaging
meat and fish in air : psychrotrophic Entero’s /Pseudomonas
in MAP (20-40% CO2) : Entero’s suppressed by LAB
fresh produce impact physiology plant tissue, not microbiology
fresh-cut leafy greens because of exudates may promote growth / but not if intact cut
baby leaves/herb leaves or fruit vegetables: keep natural strength and protection
against colonisation/growthImpact of freezing on Campylobacer
contamination Frozen (partial/total) Not f rozen (f resh)
300
200
Frequency
100
0
0 1 2 3 4 5 0 1 2 3 4 5
Campylobacter count (log10 CFU/g)
Graphs by Freez_f ig
► Survey
generalized negative binomial regression: Counts of
Campylobacter are significantly less (P= 0.006) in products made from
frozen meat (totally or partially) compared to those made from fresh meat
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beA gradual decrease (die-off) for both A restricted die-off and slight
Salmonella and E. coli O157:H7 at increase for both Salmonella and
all temperatures E. coli O157:H7 at all temperatures
15°C: below DL or molded
Typical for basil or similar
survival on leafy greens?
E. coli O157
Additional experiment on:
• Fresh-cut iceberg lettuce
• Butterhead lettuce
• Baby leaves
• Spinach leaves
• Lamb lettuce
Salmonella
3122°C: increase to higher numbers for fresh-cut iceberg
lettuce and butterhead lettuce
7°C: comparable
Presence decrease
of exudates as on
nutrients for growth
basil after 3 days
Restricted growth due to limited availability of
nutrients on whole leaves
E. coli O157
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beSalmonella, STEC, Campylobacter in
processed foods
Time/temperature recommended by ACMSF
(Advisory Committee on the Microbiological Safety of Food
UK) for the cooking of ground beef
60°C 45 min provides 6D reductions of E. coli 0157,
65°C 10 min Salmonella spp. and L. monocytogenes !
70°C 2 min E. coli as sole target organism : 70°C /
75°C 30 sec 1.3 min if 95% confidence of achieving
80°C 6 sec 6D reduction deemed acceptable
Campylobacter most susceptible to heat
treatment
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beInactivation by “appropriate” heat treatment !
5 90
80
4
70
3 60
log (KVE/g)
50
T (°C)
log (KVE/g)
2
Tintern
40
1 30
20
0
0 90 120 150 165 180 195 210 240 270 330 390 450 510 570 10
-1 0
baktijd (s)
In institutional food services,
catering, home preparation : take
care for undercooking or cross-
contamination – food handlers !!!
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beSalmonella, STEC, Campylobacter in processed foods - SHELF LIFE > 10 days Microbial stability based upon (combination) of adverse conditions (pH, aw, Temp., preservatives, atmosphere, etc.) Acidity (pH min 4.4 – 4.5) e.g. STEC (O157) strains depend on nature of the acid e.g. apple juice ! fermented/acidified foods ! Wateractivity (aw min 0.94-0.95) e.g. Salmonella strains survival in low moisture foods e.g. – confectionary / peanut butter / chocolate Campylobacter: susceptible to adverse conditions – not an issue ! Note : in composite foods Take into account addition of (contaminated) seasonings/ingredients : (semi) dried herbs, spices, nuts, berries, cereals…,
Thank you for your attention !
?
Symposium Voedselveiligheid – Salmonella Campylobacter STEC 12/03/2015, Bunnik, Nl
Mieke Uyttendaele www.foodmicrobiology.UGent.beYou can also read
