SectionIIHazardsandControlsBiologicalHazardsandControlsChemicalHazardsandControlsPhysicalHazardsandControlsBiologicalHazardsandControlsFoodbornediseaseinUSAandChina

atleast6.5millioncases,9100fatalitiesannually,andthetotalyearlycostfrom$1to$10billioninUSA

atleast10millioncasesinChina

foodbornevs.waterbornediseases(outbreaksandcases)BiologicalHazardsandControlsFoodbornediseaseoutbreaksdefinition:Twoormorepersonexperiencesasimilarillnessafteringestionofacommonfoodexception---onecaseofbotulismorchemicalpoisoning2.EpidemiologicanalysisimplicatesthefoodasthesourceoftheillnessBiologicalHazardsandControlsActualvs.Reported

foodbornediseaseoutbreakstipoftheiceberg“thereported”Foodsfrequentlyinvolvedinoutbreaksmostlyarefoodsofanimalorigin,48%oftheoutbreakscamefrombeef,chicken,eggs,pork,finfish,shellfish,turkeyordairyproducts.BiologicalHazardsandControlsStepsnecessarytocausefoodborneillnessthepathogenmustgrowtohighenoughnumberstocauseaninfectionortoproducetoxin:foodcansupportgrowthofthepathogen,andthefoodmustremaininthegrowthtemperaturerangelongenoughfortheorganismtomultiplyorproducetoxinPlacewhereillnessacquired79%incommercialsite(restaurants,cafeterialsanddelicatessens),21%inhomesprimarilyaproblemassociatedwithfoodpreparationandstorageFoodborneillnesscausedbybacteria

Biologicalhazards

bacteria,viruses,parasites,fungiandinsects.verysmallandcanbeseenwiththeaidofamicroscope.Bacteriacharacteristic(reportedinmore

casesoffoodborneillnessthananyotherhazard.)occurnaturallyintheenvironmentwherefoodsaregrown;single-celledmicroorganismsthatrequirefood,moisture,andwarmthtomultiply;mostaredestroyedbyadequatecooking,andnumbersarekepttoaminimumbypropercooling.Bacteriaandbacteriasporeallbacteriaexistinavegetativestate;somebacteriahavetheabilitytoformspores.Sporeshelpbacteriasurvivewhentheirenvironmentistoohot,cold,dry,acidic,orwhenthereisnotenoughfood.

Fig1.Thevegetativeandsporestatesofbacteriacells

VegetativecellsSpores

（optimalconditions）（stressconditions)ReproduceYESNOGrowYESNOProducetoxinYESNOResistanttostressNOYESHarmfulineatenYESNOSporesandtoxinsposeaspecialchallenge

Foodwithvegetativecellsandsporecells;Onlysporessurvivewhenfoodisheatedto74°C；

Sporesmaybecomevegetativeiffoodisnotcooledproperly;Vegetativecellsgrowandproducetoxin.Spoilageanddisease--causingbacteriaSpoilagebacteria:degradefoodsPathogenicbacteria:makepeopleillbothspoilageandpathogenicbacteriamustbecontrolledinfoodestablishmentstoimprovetheculinaryqualityandshelflifeofthefood.Whatbacterialneedinordertomultiply

Bacterialgrowth:binaryfission

Sixconditions:(temp.andtimearethemostcriticalfactorsaffectingthegrowthofbacteriainfoods.)asourceoffood(highinproteinorcarbohydrates);amildlyacidenvironment(pH4.6-7.0);atemperaturebetween5°Cand60°C(temp.dangerzone);

time(doubleinnumberevery15to30minutes,andasinglecellcanproduceoveronemillioncellsinjustfivehours);differentoxygenrequiringenvironments(dependingonthetypeofbacteria);enoughmoisture(wateractivitygreaterthan0.85).

Fig2.Bacterialgrowthcurve1.Lagphase–onlyafewhoursatroomtemperature,andcanbeincreasedbykeepingfoodsat5°Corbelow.2.Logphase–bacteriadoublinginnumberseveryfewminutes.Keepingbacteriafromreachingthelogphaseofgrowthiscriticalforfoodsafety.3.Stationaryphase–reproducingnumberequalsthataredyingoff4.Declinephase–bacteriadieoffrapidlybecausetheylacknutrientsandarepoisonedbytheirowntoxinwastes.FactorscontributingtofoodbornediseaseoutbreaksImproperstorage/holdingtemperatureInadequatecookingPoorpersonalhygieneCross-contaminationImproperreheatingPoorstoragepracticesFoodborneillnesscausedbysporeformingbacteriabacilluscereus(蠟狀芽孢桿菌屬)clostridiumbotulinum(肉毒梭狀芽孢桿菌)FoodborneillnesscausedbyNon-sporeformingbacteriaSalmonellaspp.(沙門氏菌)Shigatoxin-producingEscherichiacoli(致病性大腸桿菌)

Vibrio

parahemolylicus(副溶血弧菌)Staphylococcusaureus(金黃色葡萄球菌)Campylobacterjejuni(空腸彎曲菌)

Listeria

monocytogenes(單核細胞增生李斯特菌)

Shigellaspp.(志賀氏菌)

Table2-1MinimumgrowthtemperaturesforfoodbornepathogensOrganismMinimumtemperature（℃）

Listeria

monocytogenes1

Yersinia

entertocolitica-2

EnterotoxignicEscherichiacoil3

Vibrio

vulnificus5

Aeromonas

hydrophila0-5Non-proteolyticClostridiumbotuli3.3

Vibrio

parahaemolyticus5-7

Salmonella7-10Bacilluscereus6-10Staphylococcusaureus7-10

ProteolyticC.Botulinum10Clostridiumperfringens12Table2-2.RepresentativegenerationtimesforpsychrotrophicbacteriaTemperature(℃）Generationtime（min）

25302075151201020051200臘狀芽孢桿菌屬

10℃以下停止生長（冷藏控制）不耐熱，100℃經(jīng)20分鐘可殺死；但芽孢耐熱生長pH4.3-9.0,Aw0.95

條件致病菌：大量食用（10,000,000個/g)

肉制品,奶制品,蔬菜和水果帶菌率20%-70%肉毒梭狀芽孢桿菌

A,E型產(chǎn)生的外毒素是致死率極高的強神經(jīng)毒素當環(huán)境溫度低于15℃或高于55℃時,芽孢不能繁殖和產(chǎn)生毒素罐頭殺菌效果的指示菌:干熱180℃持續(xù)5-15min,或濕熱100℃持續(xù)3hr或高壓蒸氣121℃持續(xù)10min,才能殺死

91.48%由植物性食品引起,豆制品和罐頭沙門氏菌致病性大腸桿菌

副溶血弧菌金黃色葡萄球菌

空腸彎曲菌單核細胞增生李斯特菌

志賀氏菌食品細菌性污染指標細菌總數(shù)(食品清潔程度的標志)大腸菌群(食品受到人及動物糞便污染的標志和腸道致病菌污染的指示菌)致病菌(不得檢出)

沙門氏菌屬,志賀氏菌屬,變形桿菌屬,致病性大腸桿菌,副溶血弧菌,金黃色葡萄球菌及肉毒梭菌,鏈球菌食品細菌性危害預(yù)防與控制1.細菌性危害的衛(wèi)生管理食品原料,生產(chǎn)經(jīng)營過程,生產(chǎn)從業(yè)人員2.控制致病菌的生長和繁殖溫度,濕度,酸堿度,營養(yǎng)成分,空氣成分FoodborneillnesscausedbyvirusesVirusesaremuchsmallerthanbacteria,andtheyrequirealivinghost(human,animal)inwhichtogrowandreproduce.Properhandwashing,especiallyafterusingthetoilet,isthekeytocontrollingthespreadoffoodbo