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Facts on Foodborne Pathogens 1

Facts on Foodborne Pathogens

2 Facts on Foodborne Pathogens


Foodborne disease is caused by consuming contaminated foods or beverages. Many different disease causing microbes, or pathogens, can contaminate foods, so there are many different foodborne infections. Use this resource as a reference on foodborne bacterial and non-bacterial agents that can potentially result in food contamination.

Manitoba Agriculture, Food and Rural Initiatives assumes no legal liability for results obtained from using this material.

ContaCt InformatIonFor information on the Food Safety Program visit: manitoba.ca/agriculture/foodsafety

For more technical information or to obtain a copy of this publication, call 204-795-7968 in Winnipeg, or e-mail [email protected].


Characteristics•oxygenrequirements:aerobic• temperaturerangeforgrowth:5-55ºC•pHrangeforgrowth:4.3minimum,9.3maximum•wateractivityforgrowth:0.912-0.95•motile,spore-formingorganism•sporesresistheatanddryenvironmentconditions

foods at risk•boiledorfriedricestoredatroomtemperature•starchyfood(pasta,noodles,potatoproducts)•cookedvegetablesandsalads•cookedmeat(mincebeef,veal,lamb,pork,poultry)• ready-to-eatfoods•driedherbsandspices•driedproductssuchascerealsandflours•cream(‘sweetcurdling’or‘bittycream’spoilage)•puddings,saucesandsoups

Sources•distributedinsoil,dust,air,wateranddecaying

organic matter

Bacillus cereus

foodborne baCterIal agentS


risk to consumers•diarrhea•vomiting

transmission• ingestionofcontaminatedfood

Prevention •vegetativecellsdestroyedbyheat(56ºC,5minutes)•sporesdestroyedbyheat(126ºC,90min)•sporesloseheatresistanceinacidicenvironments,

reducepHoffoodto<4.3•mostchemicalsanitizersdestroyB. cereus on surfaces •reducewateractivityto0.921•preservativeswhichhaveaneffectonB. cereus

include:benzoate,EDTAandsorbate

testing •PEMBAagarusedforidentification;thebacteria

coloniesretainaturquoise-bluecolorafter24hours ofincubationat37ºC

•commercialkitsalsoavailable

In general•cookfoodthoroughlyandcoolrapidlyto

prevent spore germination•keephotfoodsabove60ºCandcoldfoods

below4ºC•reheatcookedfoodto74ºC


Characteristics•oxygenrequirements:micro-aerophilic(lowlevels

ofoxygen3-5%)• temperaturerangeforgrowth:25-45ºC•pHrangeforgrowth:4.9minimum,9.5maximum•wateractivityforgrowth:0.987-0.997•non-spore-formingorganism•motile

foods at risk•meatcarcassescontaminatedwithintestinal

contents during slaughter and evisceration •rawpoultry•shellfish•rawmilk•redmeat•salads•mushrooms

Sources•alimentarytractofwild,domesticatedanimals andbirds,sewage

Campylobacter jejuni


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risk to consumers•gastrointestinaldisease

transmissionFoodisavehiclefortransmission.Directtransmissionperson-to-personorfromcontactwithinfectedanimals.

Prevention • inactivatedbyheatingat55ºCandabove,cannot

survivecookingorpasteurizationtemperatures•sensitivetodrying•reducepHoffoodto<4.9,rapiddeathespecially

above refrigeration temperatures•survivespoorlyatatmosphericoxygenconcentrations

and room temperature•sensitivetoNaClconcentrationsabove1%•ascorbicacidinhibitsgrowthofseveralspecies•sensitivetosanitizers,ex:chlorine•sensitivetoultravioletradiation

testing • incubationmedia(FBP)containingblood,pyruvate,

ferroussalts,charcoalandmetabisulfite

In general•avoidcrosscontaminationfromrawfoods

tocookedfoods•reheatcookedfoodto74ºC


Characteristics•Motileandspore-formingbacteria,extremelyheat-resistantspores.ToxinproducedatpH4.83-5.2.

group I, type a, b and f (proteolytic)•oxygenrequirements:anaerobe• temperaturerangeforgrowth:10-48ºC•pHrangeforgrowth:4.6minimum,9maximum•wateractivity:0.935minimum

group II, type b, e and f (non-proteolytic)•oxygenrequirements:anaerobe• temperaturerangeforgrowth:3.3-45ºC•pHrangeforgrowth:5minimum,9maximum•wateractivity:0.970

foods at risk•uncookedvegetables(typeA)thathaveclosecontactwiththeground(asparagus,potatoes,cabbage)andgrains

•smokedandsaltedfish,seafood(typeE)•sporesgerminateinlow-acidfrozenorcoldfood•cannedproducts:vegetables,meat,corn,peppers,greentomatoes,chicken,ham,sausage,lobster

•honey

Sources•distributedindust,mud,waterandanimalcarcasses

Clostridium botulinum



risk to consumers•botulismcausedbytoxin,neurologicalsymptoms

transmission• foodcontaminatedwithsporesorvegetativecells

Prevention •sporeinactivationinlow-acid(pH>4.3)foodsby

heatingto121ºCfor3minutes• toxininactivatedbyheatingto85ºCfor1minute,

80ºCfor6minutesor65ºCfor1.5hours•vegetativecelldestroyedbyfewminutesexposureto60ºC• thermaldeathincreaseatextremepH(<5&>9)•groupIinhibitionby10%NaClandgroupII

inhibitionby5%NaCl• toxininactivationbypH11•reducepHoffoodto≤4.6•useofpreservatives,ex:nitrite,sorbates,EDTA• lacticacidbacteriaaddedinstartercultures

inhibitgrowthinmeatproducts•sporesinactivatedbyozoneorchlorinedioxide

testing •horse-bloodoregg-yolkagarincubatedanaerobically

for3days,coloniesshowlipolyticactivity

In general•holdfoodsat≤3.3ºCor≥60ºC•coolcookedfoodsunderrefrigeration


Characteristics•oxygenrequirements:anaerobe• temperaturerangeforgrowth:10-52ºC•pHrangeforgrowth:5minimum,9maximum•wateractivityforgrowth:0.93-0.95•spore-former,heatresistantspores(upto100ºC)•non-motile•producesenterotoxins

foods at risk•cookedmeat:stews,roastjoints•gravies,thicksoups,vegetablecurry(heatingdrives

air off and creates anaerobic conditions for spores togerminate)

•pies•poultrydishes,preparedinadvanceandallowed

tocoolslowly•rolledmeatsandstuffedpoultry

Sources•distributedinsoil,dust,water,vegetationandhuman

gastrointestinal tract

Clostridium perfringens



Clostridium perfringensrisk to consumers•gastroenteritis:diarrheaandabdominalpain•woundinfectionandgasgangrene

transmission• ingestionofcontaminatedfoods

Prevention •vegetativecellsaredestroyedbyheatingorby

freezing•enterotoxinsinactivatedbyheatingfor5minutesat60ºC•vegetativecellsgrowthispreventedat<12ºC•6-8%NaClinhibitsgrowth•curingsalts(ex:sodiumnitriteandchloride)can

inhibitgrowth•pHbelow5andabove8.3destroycells•highconcentrationofethanol(assanitizer)cause

spore death on food contact surfaces

testing •TSCandOPSPmediacontainingantibiotics,

incubatedanaerobicallyfor24hoursat37ºC•commercialkitsavailable

In general•cookfoodthoroughlyandcoolrapidlyto

prevent spores germination•keephotfoodsabove60ºCandcoldfoods



Characteristics•oxygenrequirements:facultativeanaerobe• temperaturerangeforgrowth:10-44.5ºC•pHrangeforgrowth:4.4minimum,9maximum•wateractivity:0.95minimum•non-spore-forming•non-motile• indicatoroffaecalcontaminationandthepossible

presence of enteric pathogens (ex: Salmonella typhi)•notheatresistant•survivesfrozenstorageforashortperiodoftime

foods at risk•rawmilk•rawmeat• rawpoultry•rawvegetables• foodsthatarehandledunderpoorhygienic

conditions

Sources• intestinaltractofhumanandwarm-bloodanimals, soilandwater

Escherichia coli


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risk to consumers•gastroenteritis:diarrhea,vomiting,stomachpain•urinarytractinfections

transmission• faecalcontaminationofwatersuppliesandcontaminated

food due to poor hygiene practices of food handlers

Prevention •rapidlyinactivatedbyheating•destroyedatpHvaluesoutsidetherangeallowing

growth(pH4.4-9)•growthcanbeinhibitedbyaslightlyacidic

environment(ex:acetic,lacticacid)• followGoodManufacturingPractices(GMPs),ex:

goodpersonnelpracticesfollowedbyfoodhandlers• thoroughlywashingoffruitsandvegetables

testing •eosin/methyleneblueagar•ß-glucuronidaseactivity,testedbyaddinga

fluorogeniccompound(MUG)inthemedia• IMViC,groupofteststodifferentiateE. coli from othermembersoftheEnterobacteriaceaegroup

In general•cookfoodthoroughlyandcoolrapidly•keephotfoodsabove60ºCandcoldfoods



Characteristics•oxygenrequirements:facultativeanaerobe• temperaturerangeforgrowth:10-44.5ºC•pHrangeforgrowth:4minimum,9maximum•wateractivityforgrowth:0.950-0.995•non-spore-forming•surviveswellinchilledorfrozenfood•non-motile•producepotenttoxinsthatcauseseveredamage

to the lining of the intestine

foods at risk•undercookedgroundmeat:(ex:rawhamburgers)• rawmilk•alfalfasprouts•unpasteurizedfruitjuice(ex:applejuice)• lettuce•cheesecurds•dry-curedsalami,fermentedsausages

Sources•cattle,cows,sheepanddeer,watercontaminated

from faecal sources

Escherichia coli o157:H7




risk to consumers•hemorrhagiccolitis(bloodydiarrhea)•hemolyticuremicsyndrome(acuterenal

failure,anemia)

transmission•contaminatedfoodorwater,person-to-person

transmission due to poor personal hygiene

Prevention •rapidlyinactivatedbyheating•cookbeefhamburgersuntilthecentrereaches

atemperatureof71.1ºC(160ºF)• thoroughlywashfruitsandvegetables•acidifyfoodstopH3.6orbelow•benzalkoniumchloride,ethanolorhotwater(70ºC)

areeffectivefoodcontactsurfacesanitizersiforganicmatter is not present

•sensitivetoultravioletradiation

testing • testsforE. coli are not sensitive to E. coliO157:H7• latexagglutinationkitscommerciallyavailable•serologicaltests




Characteristics•oxygenrequirements:facultativeanaerobe• temperaturerangeforgrowth:-0.4-50ºC•pHrangeforgrowth:4.4minimum,9.6maximum•wateractivity:0.92minimum•non-spore-forming•salttolerant,ex:cangrowin10%sodiumchloride•growsatrefrigerationconditions

foods at risk•rawmilk•cheeses(soft-ripenedvarieties)• icecream•rawvegetables•rawandfermentedmeatsausages•rawmeats(alltypes)• rawandsmokedfish•ready-to-eatfoodscontaminatedaftercooking

Sources•soil,water,sewage,domesticatedanimals,drains,

condensate,pooledwater,crackedorworntiles,ventilationsystemsandfilters

risk to consumers• listeriosis(influenza-likesymptoms,meningitis),affects

newborns,elderly,pregnantwomenandimmunecompromised individuals

Listeria monocytogenes


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transmission•contaminatedfood,ready-to-eatfoodswithlongshelf

live(ex:hotdogsanddelimeats—contaminationmayoccuraftercookingbutbeforepackaging),

•person-to-personspread

Prevention •growthisinhibitedatpHvaluesbelow4.4• inactivatedattemperaturesabove70ºC• inactivatedinvegetablesbylysozyme•sanitizers(aldehydes,alcohols,quaternary

ammoniumcompounds)areeffectiveineliminatingcontamination of food contact surfaces

•sensitivetoultravioletradiation•holdfoodsat<5ºCupto7days•holdfoodsat<7.2ºCupto4days

testing •selectiveagarscontaininglithiumchloride,

phenylethanol, glycine anhydride and antibiotics•CAMPtest(productionofacharacteristiczoneof

hemolysiswhengrowninproximitytoS. aureus)

In general•reheatcookedfoodto74ºC•avoidpost-cookingcontaminationof

ready-to-eatfoodswithlongshelflives


Characteristics•oxygenrequirements:facultativeanaerobe• temperaturerangeforgrowth:5-47ºC•pHrangeforgrowth:3.7minimum,9.6maximum•wateractivityforgrowth:0.93-0.95•non-spore-forming•motile•heatsensitive•survivesinrefrigerated,frozenordehydratedfoods

for long periods

foods at risk•undercookedmeatandpoultry•unpasteurizedmilk•eggsandeggsproducts(eggshellcontaminatedwith

faecalmaterialinthehen’scloaca,eggwhiteandyolkcontaminatedwhenbreakingtheegg)

•mayonnaisepreparedwithraweggs

Sources•gastrointestinaltractofanimals,hogs,rodents,pets,

birds, reptiles, insects

Salmonella


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risk to consumers•Salmonellosis:gastrointestinalinfection•Typhoidfever(causedbyS. typhi):fever,

headache, constipation, chills

transmission• ingestionofcontaminatedfood.•disseminatedviaanimalandhumanfaeces tosoilandwater

Prevention •avoiddirecthandlingoffoodbyinfectedemployees•acidifyfoodsatpH3.8orbelow• thoroughlywashfruitsandvegetables•heatsensitive,thermaldestruction•growthinhibitedby0.1%aceticacid•notresistanttosanitizersusedinthefoodindustry•pasteurizationofraweggs,milk

testing • impedance-conductancetechniquesusing

TMAOculturemedium•ELISAkitscommerciallyavailable




Characteristics•oxygenrequirements:facultativeanaerobe• temperaturerangeforgrowth:6.1-47ºC•pHrangeforgrowth:4.8minimum,9.3maximum•wateractivity:0.96minimum•non-spore-forming•non-motile•survivesbetteratlowtemperatures

foods at risk•uncookedprawn•salads:tuna,shrimp,chicken•rawvegetables•slicedfruitsatroomtemperature

Sources•gastrointestinaltractofhumansandother

primates,water

risk to consumers•Shigellosis(bacillarydysentery:abdominal

discomfort, cramps, diarrhea, fever, vomiting, blood,pusormucusinstools)

Shigella




transmission• ingestionofcontaminatedfoodsthroughfecal-oral

route,faecallycontaminatedwater,unsanitaryfoodhandlingandfliescarryingsewagecontamination

Prevention •rapidlyinactivatedattemperaturesabove65ºC• inactivatedatpHvalues<4• thoroughlywashfruitsandvegetables•avoidcontaminationofready-to-eatfoodsfromflies

testing •Gram-negativebrothandselenitebroth•rapidtechniquesbasedonimmunoassays•polymerasechainreaction(PCR)




Characteristics•oxygenrequirements:facultativeanaerobe• temperaturerangeforgrowth:7-50ºC•pHrangeforgrowth:4minimum,10maximum•wateractivity:0.83minimum•enterotoxinproduction•heatresistant•salttolerant(cangrowinup20%sodiumchloride)•producetoxins,especiallyinthepresenceofoxygen

and high numbers

foods at risk•rawpoultry,poultryproducts,coldcookedmeats•rawmilk,hardcheeses•saltedmeats(ex:ham,cornedbeef)•coldsweets,custardsandcream-filledbakery

products• foodrequiringconsiderablehandlingduring

preparationandkeptatslightlyelevated temperatures after preparation

Sources•skin,skinglandsandmucousmembranesofwarm

blooded animals, humans nasal tract, soil, marine andfreshwater,plantsurfaces,dustandair

Staphylococcus aureus



risk to consumers•nausea,vomiting,stomachcramps,diarrhea

transmission• foodcontaminatedbyfoodhandlersfromskin

lesions,bycoughingandsneezingoverfoods

Prevention •duringfoodfermentation,lacticacidbacteria

produce substances that are inhibitory to S. aureus, including:lacticacid,sorbateandbenzoate

•chemicalsanitizerssuchaschlorine,halogens andquaternaryammoniumcompoundseliminate S. aureus on food contact surfaces

•reducepHoffoodto≤4.2•reducewateractivityto0.83•avoiddirecthandlingofcookedready-to-eat

foods or cured/salted foods

testing •Baird-Parkeragargivescharacteristicshiny, jet-blackcoloniessurroundedbyaclearingzone

•enterotoxinidentificationfromcontaminated foodidentifiedbyELISAorreversepassive latexagglutinationtest

In general•keephotfoodsabove60ºCandcoldfoods



Characteristics•oxygenrequirements:facultativeanaerobe• temperaturerangeforgrowth:10-45ºC•pHrangeforgrowth:5minimum,10maximum•wateractivity:0.94minimum•non-spore-forming•produceapotenttoxin• toleranttoalkalineconditions

foods at risk• fruitsorvegetableswashedwithcontaminatedwater

andconsumedwithoutcooking• foodscomingfromacontaminatedenvironment:seafoodandfrog’slegs

•uncookedfishmarinadeinlime•fishandshellfish(raworpartiallycooked)•rawoysters

Sources•marineenvironment:temperate,tropicaland

sub-tropicalwaters•contaminatedwatersuppliesduetopoorsanitation

Vibrio cholerae



risk to consumers•profusewaterydiarrhea,vomiting,legcramps•rapidlossofbodyfluidsthatleadstodehydration

andshock

transmission•waterborneinfection,ingestionoffoodthatwas

incontactwithcontaminatedwater

Prevention •rapidlyinactivatedatpHvalues<4.5•sensitivetodrying• thoroughlywashallfruitandvegetables•avoidcrosscontaminationfromrawtocookedfoods•avoiddirectfoodhandlingbyinfectedemployees•peraceticacidandhypochloriteareeffectivefood

contactsurfacesanitizersintheabsenceofprotein

testing •TCBSagarincubatedfor18-24hoursat35°C

aerobicallyproducesyellowcolonies


below4ºC


Characteristics•oxygenrequirements:facultativeanaerobe• temperaturerangeforgrowth:-1-40ºC•pHrangeforgrowth:4.2minimum,10maximum•wateractivity:0.945minimum•non-sporeforming•motile• tolerate6%salt• resistenvironmentalstress:highpH,dehydration,

freezing

foods at risk•meats(beef,lamb)•raworundercookedporkproducts•oysters•rawmilk•shellfish•dairyproducts• fruitandvegetables

Sources•soil,freshwater,intestinaltractofmanyanimals.

Yersinia enterocolitica




risk to consumers•gastroenteritis:abdominalpain,diarrhea,mildfever

transmission•person-to-persontransmission,byingestionof

contaminatedfoodandwaterbornetransmission

Prevention •pasteurization•5-7%sodiumchlorideinhibitsgrowth• inactivatedbyapHvaluelowerthan4.2•growthisretardedbypotassiumsorbateupto

500ppmatpH6.5•sensitivetoultravioletradiation•avoiddirecthandlingoffoodbyinfected

food handlers•avoidpost-processingcontaminationofready-to-eat

foodswithalongshelflife

testing •CINagarincubatedat28ºCfor24hoursproduces

dark-redcentresurroundedbyatransparentbordercolonies




Characteristics•protozoa,intracellularparasite•mostlikelytobepresentasanoocyst(restingstage

equivalenttoabacterialspore)•oocystsurvivesonstainlesssteelifkeptwet•oocystsurvivesheatingat60ºCfor1minute•resistanttochlorine

foods at risk•rawmilk•rawsausages(non-fermented)•anyfoodtouchedbyacontaminatedfoodhandler•saladvegetablesfertilizedwithmanure

Sources• livestock,calves,domesticanimalsandwaterfaecally

contaminated

risk to consumers•diarrhea•seriousinfectioninimmunocompromisedpersons•abdominalpain•nausea•vomiting

Cryptosporidium parvum

foodborne non-baCterIal agentS



transmission•person-to-persontransmission,byingestionof

contaminatedfoodandwaterbornetransmission

Prevention •pasteurization• temperatureabove73ºCrendertheoocyst

non-infectious• inactivatedbyfreezingat–15ºC•acidconditions(pH4)resultsinlossofoocystviability•sensitivetodrying•sensitivetoultravioletlight•0.35%peraceticacidinactivatesoocysts•avoidcrosscontaminationfromrawtoready-to-

eat foods• thoroughlywashfruitsandvegetables

testing •EnzymeImmunoAssay(EIA)andImmunoFluorescent

Antibody(IFA)(bothdirectandindirectmethods)candetect Cryptosporidium




CharacteristicsRotavirus,astrovirus,hepatitisE,adenovirus,calicivirus:

•donotreplicateinfood,requirehumancellstomultiply

•passthroughthegastrointestinaltract

• resistanttoenvironmentalstresssuchasheatand acid conditions

•stableatpH3

•resistfreezinganddrying

foods at risk• foodsmaybecomecontaminatedduring:handling,

preparation, serving or processing •salads•shellfishgrowninshallow,coastalwaters

Sources•contaminatedwaterandcontaminationbyinfected

food handlers

risk to consumers•diarrheaandvomiting•severechildhoodgastroenteritis

Enteric Viruses


(otherthanhepatitisAandnoroviruses)



transmission•allfoodbornevirusesaretransmittedbyfecal-

oral route •canalsobetransmittedbyingestingcontaminated

foodsthatundergoextensivehandlingintheir preparationandareconsumedwithoutreheating

Prevention •heatingfor30minutesat50ºC•reducepHlevelsto<3orincreasetopH>10• thoroughlywashfruitsandvegetables• thoroughcleaninganddisinfectionmustfollow

after vomiting on food premises• foodhandlerstrainedineffectivehandwashingtechniques

testing •rapidantigendetectionofentericvirusinstool

samples •strainsfurthercharacterizedbyenzymeimmunoassay

In general•reheatcookedfoodto74ºC•boil,filterortreatnon-potablewaterbefore

drinking


Characteristics•survivesinfoodandwaterascysts(infectiveform)

•watersurvivalatlowtemperatures(~8ºC)

•coolmoistconditionsfavorsurvival

•cystsresistanttoultravioletradiationandchlorination

foods at risk•salads•vegetablessuchaslettuce• fruitssuchasstrawberries• foodswashedwithcontaminatedwaterorhandled

by infected employees•herbs• rootcrops(beet,carrot)

Sources•environmentalwaterswhichhavebeenfaecally

polluted• foundinanimals,birds,reptilesandamphibians

risk to consumers•Giardiasis:diarrhea,abdominalcramps,nausea,weightlossanddehydration

Giardia lamblia




transmission•person-to-personduetopoorhygiene•contaminatedwater,foodcontaminatedbywater

or by a food handler

Prevention •cystseliminatedbynormalcookingprocedures

in food preparation•heatingfoodto60-70ºCfor10min•boilingfor3minutes•pasteurization•cystsinactivatedbyfreezing•waterfiltration(8μmporesizefilter)•avoidcrosscontaminationfromrawto

ready-to-eat foods• thoroughlywashfruitsandvegetables•avoidfoodhandlingbyinfectedemployees

testing •detectioninstoolsamplesbymicroscopicexamination•ELISAtest

In general•reheatcookedfoodto74ºC•boil,filterortreatnon-potablewaterbefore

drinking


Characteristics•highresistancetochemicalandphysicalagents,

including: heat, acid and solvents

•underfreezingandrefrigerationconditions the virus remains infective

•stableatpH1

foods at risk•milk• fruits(strawberries,raspberries)•saladvegetables(lettuce)•shellfish•manuallypreparedfoodproducts•cream-filledcookies•coldcuts(precookedorcuredmeat,sausages

or meat loaves, that are sliced and served on sandwichesoronpartytrays)

Sources•humanfaeces,contaminatedwater(freshand

seawater,wastewater,marinesediments)andsoil

Hepatitis a Virus (HaV)




risk to consumers•hepatitisA:fever,nausea,vomiting,liverdamage,malaise,anorexia,jaundice

transmission•Transmissionoccursbythefecal-oralroute,eitherby

directcontactwithaHepatitisAvirusinfectedpersonorbyingestionofHepatitisAviruscontaminatedfoodorwater.

Prevention •cookshellfishat90ºCfor1.5min• thoroughlywashallfruitandvegetables•avoidhandlingoffoodbyinfectedemployees•ensuretrainingoffoodhandlersineffectivehand

washing(asymptomaticfoodhandlerscanspread theinfection)

• infectivityisdecreasedbyexposureto70%alcohol• inactivatedbyultravioletradiation

testing • foodisrarelyanalyzedbecauseofthelongincubationperiod(2-6weeks)

In general•boil,filterortreatnon-potablewaterbefore

drinking


Characteristics•mostwidelyrecognizedviralagentassociated

withfoodandwaterborneoutbreaks

•stableandresistanttoheatandacidicconditions

•underrefrigerationandfreezingconditionsthe virus remains intact

•resistgastricacidsatpH3-4

•resistanttodrying

foods at risk•shellfish,raworinsufficientlysteamedclams

andoystersposesahighrisk•salads•waterandice•manuallypreparedfoodproducts•bakeryproducts

Sources•environmentalsurfaces(ex:carpets),fecesfrom

infectedhumansmaycontaminatesoilorwater• fecalpollutionfromsewagedischarges

norovirus




risk to consumers•projectilevomiting•stomachcramps•diarrheaandabdominalpain

transmission• ingestionofcontaminatedfoodduetopoorhygiene

practices •person-to-personspreadfollowingprojectilevomiting• transmissionviacontaminatedsurfaces(carpetsand

toiletseats)

Prevention •cookshellfishat90ºCfor1.5min• thoroughlywashallfruitandvegetables•avoidhandlingoffoodbyinfectedfoodhandlers•ensuretrainingoffoodhandlersineffectivehand

washing(asymptomaticfoodhandlerscanspread theinfection)

testing •molecularmethods,includingDNAsequencing;the

virusisnon-culturableanddoesnotgrowinfood

In general•boil,filterortreatnon-potablewaterbefore

drinking


Characteristics•bacteriaactasanindirectagentoffoodpoisoning

byconvertingafoodcomponent(histidine)intoaharmfulcompound(histamine)

•histamineisproducedduringtemperatureabuse and spoilage

•cookingorheatingdoesnotdestroyhistamine

•vacuumpackagingisnoteffectiveinretardinghistamine production

foods at risk•scombroidfish:tuna,bonito,mackerel(temperatureabusedrawfishallowsbacterialgrowthandtoxinproduction)

•fish:sardines,pilchards,herrings•cannedfish•cheese,speciallySwisscheese(ripenedat

warmtemperatures)• fermentedmeatproducts,ex:salami• fermentedvegetables,ex:sauerkraut

Sources• foodscontaminatedwithhistamine,mainlyfish

scombroid (Histamine) Poisoning




risk to consumers•chemicalintoxication:diarrhea,facialandneck

rashes,inflammation,dizziness,itching,vomiting

transmission• ingestionofcontaminatedfoodwithhistamine

Prevention • incheeseproductiontheuseofstartercultures

withlowdecarboxylaseactivitypreventhistamineformation

•shortfermentationtimeformeatproducts,useappropriate starter culture and rapidly decrease thepH

• transportandstorefishunderrefrigeration•chillfishrapidlyto<10ºC•holdfishat0ºCupto14days,4.4ºCupto7days• rawfishshouldbepurchasedfromknownand

reputable suppliers

testing •FDAchemicalmethod:alcoholextractionfollowed byfluorescencespectroscopy

•Commercialkitsforhistaminedetectionavailable

In general•fishshouldberapidlyretrievedfromthewater,

cooledasquicklyaspossibleandhandledusing good hygienic procedures


glossaryaerobe:requiresoxygen

anaerobe:requirestheabsenceofoxygen

baird-Parker agar:lithiumchloride,tellurite,eggyolkand pyruvate

CamP test: named for the initials of the 4 discovers, Christie,Atkins,MunchandPetersen

CIn agar: cefsulodin, irgasan and novobiocin

elISa:enzyme-linkedimmunosorbentassay

enterotoxin:toxinreleasedbyamicro-organisminthelowerintestine.Italtersthepermeabilityoftheintestinalwallcausingwaterandelectrolytestoleakintotheintestinal tract.

facultative anaerobe: growseitherwithorwithoutoxygen

fbP agar:ferroussulfate,sodiumbisulfiteandsodiumpyruvate

Hemolysis:breakdownofredbloodcells

ImViC test: indoletest,methylredandVoges-Proskauertest and citrate test

micro-aerophilic:requireslimitedlevelsofoxygen

mUg:fluorogen4-methylum-belliferyl-ß-D-glucuronide

naCl: sodium chloride

oPSP agar:oleandomycin,polymyxin,sulfadiazineand perfringens


Pemba agar:polymyxin,pyruvate,eggyolk,mannitoland bromothymol blue agar

ppm:partspermillion,ex:oneparticleofagivensubstance for every 999,999 other particles

tCbS agar: thiosulfate, citrate, bile salt and sucrose

tmao: selenite-cysteine broth containing dulcitol andtrimethylamineoxide

tSC agar:tryptose,sulfiteandcycloserine


manitoba agriculture, food and rural Initiativesmanitoba.ca/agriculture/foodsafety

[email protected]

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