Bacillus, Corynebacterium, Nocardia, Mycobacterium, Clostridium, anaerobic, non-spore-forming Gram-positive Bacteria, anaerobic Gram-negative BacteriaSpore-Forming Gram-positive Bacteria (Bacillus, Clostridum)Anaerobes including anaerobic Gram-negative BacteriaSectionIGrampositiverodsSporeformingNonsporeformingAnaerobicAerobicClostridium sppBacillus sppCorynebacteriumGramPositiveBacilliBacillusspp.B. anthracis and B. cereus.B. anthracisisresponsibleforthediseaseanthrax.B. cereusispredominantlyresponsibleforfoodpoisoninginhumans.Theemetictype,associatedwithfriedriceThediarrhealtype,associatedwithmeatdishesandsauces B. anthracisgram-positivespore-formingrod-shapedSporesareresistanttoharshconditions,includingheat,radiation,disinfectants,desiccation,andsoon.The2001anthraxattacksCapitolHillduringtheanthraxattacksBruceIvinsisdeclaredasthesolesuspect.www.fredericknewspost.comThebioterrorismeventresultedin22casesofanthrax:11inhalationand11cutaneous.Fiveofthepatientswithinhalationanthraxdied.annespeckhard.comB. anthracis:pathogenesisAnthraxisprimarilyadiseaseofherbivores(goats,sheep,cattle,horses,etc),humansbecomeinfectedincidentallybycontactwithinfectedanimalsortheirproducts.Cutaneous(injuredskin)themostcommonform,causesalocalizedinflammatoryblacknecroticlesion(eschar焦痂焦痂)PulmonaryhighlyfatalandcharacterizedbysuddenmassivechestedemafollowedbycardiovascularshockGastrointestinal(mucousmembranes)rarebutalsofatal(causesdeathto25%)typeresultsfromingestionofsporesPathogenesisVirulencefactorsi)capsule(containspoly-D-glutamicacidwhichisantiphagocytic),encodedbyplasmidpXO2;strainswithoutcapsuleareusuallynotvirulentii)exotoxinsencodedonplasmidpXO1,threeproteins;tobeactive,theLFandEFneedtocombinewithPA.1.protectiveantigen(PA),bindstospecificcellreceptors2.lethalfactor(LF),+PAformlethaltoxin,causeofdeath3.edemafactor(EF),anadenylatecyclase,+PAformedemafactorANTHRAX TOXINSLFEFPAPAPALFHostProteaseHOST CELL20 kDaulethaltoxin(PA+LF) oredemafactor (PA+EF) is internalized by endocytosis u the LF or EF cross the membrane into the cell via PA-mediated channelsEndospores are phagocytosed by macrophages and germinateMacrophages containing bacilli detach and migrate to the regional lymph node.Vegetative anthrax bacilli grow in the lymph node, creating regional hemorrhagic lymphadenitisBacteria spread through the blood and lymph and increase to high numbers, causing severe septicemiaHigh levels of exotoxins are produced that are responsible for overt symptoms and death.ClinicalfindingsInhumans,approximately95%ofcasesarecutaneousanthraxand5%areinhalation.largeblackskinlesions(eschar)DiagnosticlaboratorytestsStainedsmearsfromthelocallesionorofbloodfromdeadanimalsoftenshowchainsoflargegrampositiverods.AnELISAhasbeendevelopedtomeasureantibodiesagainstedemaandlethaltoxins,butthetesthasnotbeenextensivelystudied.Somepublichealthlaboratoriesmayalsohavenucleicacidamplificationassaysavailable.TreatmentManyantibioticsareeffectiveagainstanthraxinhumans,buttreatmentmustbestartedearly.Ciprofloxacinisrecommended.AfterthepotentialexposuretoB. anthracisasanagentofbiologicalwarfare,prophylaxiswithciprofloxacinordoxycyclineshouldbecontinuedfor4weekswhilethreedosesofvaccinearebeinggiven,orfor8weeksifnovaccineisadministered.EpidemiologyandcontrolSoiliscontaminatedwithanthraxsporesfromthecarcassesofdeadanimals.Thesesporesremainviablefordecades.Grazinganimalsinfectedthroughinjuredmucousmembranesservetoperpetuatethechainofinfection.Controlmeasuresinclude1)disposalofanimalcarcasses,2)decontaminationofanimalproducts,3)protectiveclothingandglovesforhandlingpotentiallyinfectedmaterials,4)activeimmunizationofdomesticanimalswithliveattenuatedvaccines.Personswithhighoccupationalriskshouldbeimmunized.AnaerobicorganismAnanaerobic organismoranaerobeisanyorganismthatdoesnotrequireoxygenforgrowth.Itcouldpossiblyreactnegativelyandmayevendieifoxygenispresent.Therearethreetypes:obligateanaerobes,whichcannotuseoxygenforgrowthandareevenharmedbyitaerotolerantorganisms,whichcannotuseoxygenforgrowth,buttoleratethepresenceofitfacultativeanaerobes,whichcangrowwithoutoxygenbutcanutilizeoxygenifitispresent1:Obligateaerobic(oxygen-needing)bacteriagatheratthetopofthetesttubeinordertoabsorbmaximalamountofoxygen.2:Obligateanaerobicbacteriagatheratthebottomtoavoidoxygen.3:Facultativebacteriagathermostlyatthetop,sinceaerobicrespirationisthemostbeneficialone;but,aslackofoxygendoesnothurtthem,theycanbefoundallalongthetesttube.4:Microaerophilesgatherattheupperpartofthetesttubebutnotatthetop.Theyrequireoxygenbutatalowconcentration.5:Aerotolerantbacteriaarenotaffectedatallbyoxygen,andtheyareevenlyspreadalongthetesttube.no oxidative phosphorylationfermentationkilled by oxygenlack certain enzymescatalase *H2O2 H20 + O2peroxidase *H2O2 H20 /NAD to NADH Obligate (strict) anaerobesInsteadofoxygen,obligateanaerobesusealternateelectronacceptorsforcellularrespirationsuchassulfate,nitrate,iron,manganese,mercury,andcarbonmonoxide.Whystrictanaerobesaresensitivetooxygen?Dissolvedoxygenincreasestheredoxpotentialofasolution,andhighredoxpotentialinhibitsthegrowthofsomestrictanaerobes.Forexample,methanogensgrowataredoxpotentiallowerthan-0.3V.Sulfideisanessentialcomponentofsomeenzymes,andmolecularoxygenoxidizesthistoformdisulfide,thusinactivatingcertainenzymes.Organismsmaynotbeabletogrowwithoutthesedeactivatedenzymes.Growthmaybeinhibitedduetoalackofreducingequivalentsforbiosynthesis,becauseelectronsareexhaustedinreducingoxygen.Spore-forming:rod,Gram(+)-ClostridiumNonspore-forming:Rod,Gram(+)PropionibacteriumBifidobacteriumLactobacillusEubacteriumActinomycesRod,Gram(-)BacteroidesFusobacteriumCampylobacterCocci,Gram(+)PeptococcusPeptostreptococcusCocci,Gram(-)VeillonellaCategoryBacterialFloraoftheBodySiteTotalBacteriaRatio(per/mlorgm)Anaerobes:AerobesUpperAirwayNasalWashings103-1043-5:1Saliva108-1091:1ToothSurface 1010-10111:1GingivalCrevice1011-10121000:1GastrointestinalTractStomach102-1051:1SmallBowel102-1041:1Ileum104-1071:1Colon1011-10121000:1FemaleGenitalTractEndocervix108-1093-5:1Vagina108-1093-5:1 Enterobacteriaceae (facultative anaerobes) anormalpartofthegutflora playimportantrolesinnutrientassimilation Strict anaerobes opportunistic pathogensInfectioncausedbystrictanaerobesSites throughout body Muscle, cutaneous/sub-cutaneous necrosisAbscesses PolymicrobialnatureMostanaerobicinfectionsareassociatedwithcontaminationoftissuebynormalfloraofthemucosaofthemouth,pharynx,gastrointestinaltract,orgenitaltract.Typically,multiplespeciesarefound,includingbothobligateandfacultativeanaerobes.Aerobicbacteriamayalsobepresent,butobligateaerobesaremuchlesscommonthananaerobesandfacultativeanaerobes.Generaldiagnosisofanaerobicinfections1.Foul-smellingdischarge(duetoshort-chainfatty-acidproductsofanaerobicmetabolism)2.Infectioninproximitytoamucosalsurface(anaerobesarepartofthenormalflora)3.Gasintissues(productionofCO2andH2)4.NegativeaerobicculturesBesides,colonymorphology,pigmentation,andmetabolismarehelpfulinidentifyinganaerobes.The clostridia in human infectionsopportunistic pathogens- some of the deadliest diseasesBotulismtetanusgasgangrene- less life-threatening diseasesfoodpoisoningpseudomembranouscolitisClostridum botulinum: BotulismC. botulism existsinsoil,thesporesfindtheirwayintopreservedorcannedfoodswithlowoxygenlevels,andnutrientsthatsupportgrowth.Germinateandelaboratethetoxinsasgrowthandlysisoccur.microbiologybytes.comaGram-positive,rodshapedbacteriumthatproducesneurotoxinsknownasbotulinumneurotoxinstypesA-G,whichcausesflaccidmuscularparalysisseeninbotulismananaerobicspore-former,whichproducesoval,subterminalendosporesBotulism, ToxinTypesofC. botulinumaredistinguishedbytheantigenictypeoftoxintheyproduce.Sporesoftheorganismarehighlyresistanttoheat,withstanding100forseveralhours,HeatresistanceisdiminishedatacidpHorhighsaltconcentration.causesmuscularparalysisA14-year-oldwithbotulism Mechanism of botulism toxinBotoxaneurotoxin(tradenameBotox)thatisusedclinicallyinsmallquantitiestotreatstrabismusandfacialspasmsandotherneurologicaldisorderscharacterizedbyabnormalmusclecontractions;isalsousedbycosmeticsurgeonstosmoothfrownlinestemporarilyurbanretreat.comPathogenesisThemostcommonoffendersarespiced,smoked,vacuum-packed,orcannedalkalinefoodsthatareeatenwithoutcooking.Insuchfoods,sporesofC. botulinumgerminate;underanaerobicconditions,vegetativeformsgrowandproducetoxin.Ininfantbotulism,honeyisthemostfrequentvehicleofinfection.Thevegetativecellsproducetoxinastheymultiply;theneurotoxinthengetsabsorbedintothebloodstream.ClinicalfindingsSymptomsbegin18-24hoursafteringestionofthetoxicfood,withvisualdisturbances(incoordinationofeyemuscles,doublevision),inabilitytoswallow,andspeechdifficulty;signsofbulbarparalysisareprogressive,anddeathoccursfromrespiratoryparalysisorcardiacarrest.Gastrointestinalsymptomsarenotregularlyprominent.Thereisnofever.Themortalityrateishigh.Patientswhorecoverdonotdevelopanti-toxinintheblood.Infantbotulismmaybeoneofthecausesofsuddeninfantdeathsyndrome.C. botulinum andbotulinumtoxinarefoundinfecesbutnotinserum.DiagnosticlaboratorytestsToxincanoftenbedemonstratedinserumfromthepatient,andtoxinmaybefoundinleftoverfood.Ininfantbotulism,C. botulinum andtoxincanbedemonstratedinbowelcontentsbutnotinserum.Toxinmaybedemonstratedbypassivehemagglutinationorradioimmunoassay.TreatmentBotulinumneurotoxinsarethemostpotenttoxinsknownbutcanbeneutralizedbyspecificantibodies.Potentantitoxinstothreetypesofbotulinumtoxins,trivalent(A,B,E).Antitoxinmustbepromptlyadministeredintravenouslywithcustomaryprecautions.Adequateventilationmustbemaintainedbymechanicalrespirator,ifnecessary.Thesemeasureshavereducedthemortalityratefrom65%tobelow25%.Epidemiology,preventionandcontrolSincesporesofC. botulinum arewidelydistributedinsoil,theyoftencontaminatevegetables,fruits,andothermaterials.Strictregulationofcommercialcanninghaslargelyovercomethedangerofwidespreadoutbreaks.Theriskfromhome-cannedfoodscanbereducedifthefoodisboiledformorethan20minutesbeforeconsumption.ToxoidsareusedforactiveimmunizationofcattleinSouthAfrica.Botulinumtoxinisconsideredtobeamajoragentforbioterrorismandbiologicalwarfare.C. tetaniGrowthonCookedMeatMedium(left)Biological traitsBiological traitsPathogenesisofC. tetanicausestetanusnotinvasive,strictlylocalizedMajortoxins tetanospasmin（破伤风痉挛毒素（破伤风痉挛毒素) tetanolysin （破伤风溶血毒素（破伤风溶血毒素)Tetanospasminastrongneurotoxin,thelethaldosagetohumanislessthan1gTetanustoxinspreadsthroughtissuespacesintothelymphaticandvascularsystems.Itentersthenervoussystemattheneuromuscularjunctionsandmigratesthroughnervetrunksandintothecentralnervoussystem.Sensitivetoheat，ineffectiveafter65,30min Mechanism of TetanospasminTypicalsymptomsThename“tetani”derivesfromofatension,referringtothetension(causedbytetanus)inthemuscles.DiagnosisRestsontheclinicalpictureandahistoryofinjury:(1)Infectiongenerallyoccursthroughwoundcontaminationandofteninvolvesacutordeeppuncturewound;(2)Astheinfectionprogresses,musclespasmsdevelopinthejaw(thusthename“lockjaw”)andelsewhereinthebody.Theprimarydifferentialdiagnosisoftetanusisstrychninepoisoning.！NeitherpreventivenortherapeuticuseofantitoxinshouldbewithheldpendingdemonstrationofC. tetani existence.Immunity&Prevention！Thetoxin(tetanospasmin)bindtotheneuronsisirreversible.Controlmeasuresarenotpossiblebecauseofthewidedisseminationoftheorganisminthesoilandthelongsurvivalofitsspores.Tetanuscanbepreventedbyvaccinationwithtetanustoxoid.Acombinedvaccine,DPTvaccine,whichincludesvaccinesagainstdiphtheria,pertussis,andtetanus.TheUS-CDCrecommendsthatadultsreceiveaboostervaccineeverytenyearsTreatmentDeadandinfectedtissueshouldberemovedbysurgicaldebridement.Prophylacticuseofantitoxin,tetanusantitoxin,TATAntibiotics:metronidazole,penicillin C. perfingensfoodsafetynetwork.caacommoncauseoffoodpoisoningIllnessresultswhenalargenumberofbacteriaareconsumed,usuallyfromafoodthathasremainedbetween4oCand60oCforanextendedperiodoftime.Thebacteriasporulateinthepersonsintestinesandreleaseatoxinwhichresultsinsymptoms.Thesporessurviveextremelyharshconditions,includingboilingforoveranhour.WhereisC. perfringensfound?Thebacteriaarenotroutinelypasseddirectlybetweenpeople,butratherthroughcross-contaminationoffoods.C. perfringensisanaerobicmeaningitgrowswithoutoxygen,therebymakingthicksoups,graviesandpiesanidealenvironmentforgrowth.C. perfringensiswidelydistributedintheenvironment.Healthyanimalsandhumanscanharbourthisbacteriumintheirintestines.Sporescanalsobefoundinsoil,dustandvegetation. (lactose)highgas(H2andCO2)production,stormyfermentation,hemolysisNaglersreaction,-toxinC. perfringens, ToxinAnenterotoxinofC. perfringensisacommoncauseoffoodpoisoning.Whenmorethan108vegetativecellsareingestedandsporulateinthegut,enterotoxinisformed.Manyofthesetoxinshavelethal,necrotizing,andhemolyticproperties.The-toxinofC. perfringenstypeAisalecithinase.TheactionofC. perfringensenterotoxininvolvesmarkedhypersecretioninthejejunumandileum,withlostoffluidsandelectrolytesindiarrhea.Muchlessfrequentsymptomsincludenausea,vomiting,andfever.PathogenesisAmixedinfectionistherule.Inadditiontothetoxigenicclostridia,proteolyticclostridiaandvariouscocciandgram-negativeorganismsarealsousuallypresent.Clostridialbacteremiaisafrequentoccurrenceinpatientswithneoplasms.InNewGuinea,C. perfringenstypeCproducesanecrotizingenteritis(pigbel)thatcanbehighlyfatalinchildren.ImmunizationwithtypeCtoxoidappearstohavepreventivevalue.GasgangreneOccurswhenasofttissuewoundiscontaminatedby C. perfringens,asoccursintrauma,septicabortion,andwarwounds.Couldbefatal.adoptamicrobe.blogspot.comClinicalfindingsFromacontaminatedwound,theinfectionspreadsin1-3daystoproducecrepitationinthesubcutaneoustissueandmuscle,foul-smellingdischarge,rapidlyprogressingnecrosis,fever,hemolysis,toxemia,shock,anddeath.C. perfringensfoodpoisoningusuallyfollowstheingestionoflargenumbersofclostridiathathavegrowninwarmedmeatdishes.Thetoxinformswhentheorganismssporulateinthegut,withtheonsetofdiarrheausuallywithoutvomittingorfever-in6-18hours.Theillnesslastsonly1-2days.DiagnosticlaboratorytestsSpecimensconsistofmaterialfromwounds,pus,andtissue.Thepresenceoflargegram-positiverodsinGram-stainedsmearssuggestsgasgangreneclostridia;sporesarenotregularlypresent.Aclottornbygasin24hoursissuggestiveofC. perfringens.Oncepurecultureshavebeenobtained,couldbeidentifiedbybiochemicalreactions,hemolysis,andcolonyform.Lecithinaseactivityisevaluatedbytheprecipitateformedaroundcoloniesoneggyolkmedia.Finalidentificationrestsontoxinproductionandneutralizationbyspecificantitoxin.TreatmentMostimportantly,promptandextensivesurgicaldebridementoftheinvolvedareaandexcisionofalldevitalizedtissue,inwhichtheorganismsarepronetogrow.Administrationofantimicrobialdrugs,particularlypenicillin,isbegunatthesametime.Hyperbaricoxygenmaybeofhelpinthemedicalmanagementofclostridialtissueinfections,Itissaidto“detoxify”patientsrapidly.Antitoxinsareavailable,usuallyintheformofconcentratedimmuneglobulins.Thereislimitedevidenceforitsefficacy.PseudomembranouscolitisClostridum difficile Clostridiaareanaerobic,spore-formingrods(bacilli).C. difficileisthemostseriouscauseofantibiotic-associateddiarrhea(AAD)andcanleadtopseudomembranouscolitis,asevereinfectionofthecolon,oftenresultingfromeradicationofthenormalgutflorabyantibiotics.(H&Estain)C. difficile relativelyresistanttomostcommonlyusedantibiotics.-Associatedwithorfollowingantibioticuse,thenormalgastrointestinalfloraissuppressedandC. difficileproliferates,producingcytopathictoxinandenterotoxin.-Thediagnosisismadebydemonstratingneutralizablecytotoxininthestool. C. difficile, toxin&clinicalfindingsAdministrationofantibioticsresultsinproliferationofdrug-resistantC. difficilethatproducestwotoxins.ToxinA,apotententerotoxinthatalsohassomecytotoxicactivity,bindstothebrushbordermembranesofthegutatreceptorsites.ToxinBisapotentcytotoxin.Bothtoxinsarefoundinthestoolsofpatientswithpseudomembranouscolitis.DiagnosticlaboratorytestsCytotoxicityassayC. difficiletoxinshaveacytopathiceffectincellculture,andneutralizedwithspecificanti-seraisthepracticalgoldstandardforstudiesinvestigatingnewdiagnostictechniques.ToxinELISA AssessmentoftheAandBtoxinsbyELISAfortoxinAorB(orboth)hasasensitivityof6399%andaspecificityof93100%.Otherstooltests Stoolleukocytemeasurementsandstoollactoferrinlevelshavealsobeenproposedasdiagnostictests,butmayhavelimiteddiagnosticaccuracy.Real-TimePCRBytheendof2009,3differentReal-TimePCRtestshadachieved510(k)clearancefromtheFDA.Foreachtest,sensitivitiesaregenerallyreportedas95-99%andspecificitiesas92-96%,dependingonthetestsandthesizeofthepatientpool.TreatmentAsymptomaticcolonizationwithC. difficileiscommon.Mildcasesgenerallydonotrequirespecifictreatment.PatientsshouldbetreatedassoonaspossiblewhenthediagnosisofClostridium difficilecolitisismadetoavoidfranksepsisorbowelperforation.Toreducecomplications,physiciansoftenbegintreatmentbasedonclinicalpresentationbeforedefinitiveresultsareavailable.Knowledgeofthelocalepidemiologyofintestinalfloraofaparticularinstitutioncanguidetherapy.Inaddition,oralrehydrationtherapyisusefulinretainingfluidsduringthedurationofdiarrhoea.PreventionandcontrolThemosteffectivemethodisproperantimicrobialprescribing.Infectioncontrolmeasures,suchaswearinggloveswhencaringforpatients,havebeenproventobeeffectiveatprevention.ThisworksbylimitingthespreadofC. difficileinthehospitalsetting.Inaddition,washingwithsoapandwaterwilleliminatethesporesfromcontaminatedhands,butalcohol-basedhandrubsareineffective.Bacteriotherapy?TreatmentwithvariousoralsupplementscontaininglivebacteriahasbeenstudiedineffortstopreventC. difficile-associatedinfection/disease.ArandomizedcontrolledtrialusingaprobioticdrinkcontainingLactobacillus casei,L bulgaricus,andStreptococcus salivarius subsp. thermophiluswasreportedtohavesomeefficacy.Spore-forming:rod,Gram(+)-ClostridiumNonspore-forming:Rod,Gram(+)PropionibacteriumBifidobacteriumLactobacillusEubacteriumActinomycesRod,Gram(-)BacteroidesFusobacteriumCampylobacterCocci,Gram(+)PeptococcusPeptostreptococcusCocci,Gram(-)VeillonellaCategoryBifidobacterium,aGram+non-spore-forminganaerobenon-motile,oftenbranchedbacillusendosymbioticinhabitantsofthegastrointestinaltract,vaginaandmouth(B. dentium)oneofthemajorgeneraofbacteriathatmakeupthecolonfloraSomebifidobacteriaareusedasprobiotics B. adolescentistotreatconstipation,diarrheaBacteroides fragilis, aGram-non-spore-forminganaerobebacillusbacteria couldcauseinfectionsafterabdominalsurgery Prominent capsule anti-phagocytic abscess formation Endotoxin low toxicity EpidemiologyNormalfloraofmouth,URT,intestinaltract,urogenitaltractPathogenicity(opportunisticpathogen)Wounds,abscessesinbodysitesbelowthediaphragmBacteremia(败血症)B. fragilisB. fragilisPalestaining,pleomorphicrodwithroundedends;safetypinappearanceLookforgrowthonBBE,seeesculinhydrolysisaroundthecolony,whiteprecipitationCanuseantibioticdisk,GLCforidentificationLabDiagnosisReview: Problems in identification of anaerobic infectionsair in sample (sampling, transportation)no growthidentification takes several days or longerlimiting usefulnessoften derived from normal flora sample contamination can confuse Review:CharacteristicsofAnaerobicInfections1.Most anaerobes are usually commensalsOriginatefromourownfloraBadguysdoexist2.Predisposing ConditionsBreechesinthemucocutaneousbarrierdisplacenormalfloraCompromisedvascularsupplyTraumawithtissuedestructionAntecedentinfectionReview:CharacteristicsofAnaerobicInfections3.Complex FloraMultiplespeciesAbdominalInfectionAvgof5speciesLesscomplexthennormalfloraFecalflora400differentspeciesThosepredominantinstoolarenotinfectingspeciesVeillonella,BifidobacteriumrarelypathogenicSpeciesuniquelysuitedtocauseinfectionpredominate4.Synergistic Mixture of Aerobes & AnaerobesE. coliConsumeO2AllowgrowthofanaerobesAnaerobespromotegrowthofotherbacteriabybeingantiphagocyticandproducing-lactamasesReview:Othercommonvirulencefactors1.Anti-phagocyticcapsuleAlsopromoteabscessformation2.TissuedestructiveenzymesB. fragilisproducesvarietyofenzymes(lipases,proteases, collagenases) that destroy tissue AbscessFormation3.Beta-lactamaseproductionB. fragilis protectthemselvesandotherspeciesinmixedinfections4.SuperoxidedismutaseproductionProtectsbacteriafromtoxicO2radicalsastheymoveoutofusualnicheTranslationofKeytermsAnaerobic bacteria 厌氧性细菌厌氧性细菌Clostridium 厌氧芽孢梭菌属厌氧芽孢梭菌属C. tetani 破伤风梭菌破伤风梭菌Tetanospasmin 破伤风痉挛毒素破伤风痉挛毒素Tetani antitoxin , TAT 破伤风抗毒素破伤风抗毒素C. perfringens 产气荚膜梭菌产气荚膜梭菌Nagler reaction 卵磷脂酶试验卵磷脂酶试验Stormy fermentation 汹涌发酵汹涌发酵Gas gangrene 气性坏疽气性坏疽TranslationofKeytermsC. botulinum 肉毒梭菌肉毒梭菌C. difficile 艰难梭菌艰难梭菌Bacteroides 类杆菌属类杆菌属B. fragilis 脆弱类杆菌脆弱类杆菌Bifidobacterium 双歧杆菌属双歧杆菌属ReviewQuestions1.Whatclues/symptomsareconsideredaspossibleanaerobicInfection(s)?2.Whatisthegeneralprincipleontreatmentofanaerobicinfection(s)?3.Selectonebacteriumcoveredinthislecture,summarizetherelatedknowledgeyouhavelearned.4.Refertootherreviewquestionsinthebookchapter.ReferencesandCitationJawetz,Melnick,&AdelbergsMedicalMicrobiology,25th,26th(McGraw-HillEducation)http:/en.wikipedia.org,http:/www.google.comhttp:/basic.shsmu.edu.cn/jpkc/micro2/2006ppt/index.aspPPTslidesfromDr.WangYY,ZhangJQ,etc.PPTslidesfromvariouson-lineresources