大二下学习-微生物课件8.enteric bacilli

Chapter8Enterobacteriaceae(EntericGram-negativeRodsorEntericbacilli)

p.123本章重点及难点掌握致病性大肠埃希菌及其所致疾病掌握志贺菌属与沙门菌属的致病性掌握志贺菌属与沙门菌属微生物学检查步骤熟悉肠杆菌科的共同特性了解大肠埃希菌的微生物学检查及防治原则、志贺菌和沙门菌的防治原则、沙门菌分类、其他肠道细菌DefinitionofEnterobactericeae

Thelarge,heterogeneousgroupofgram-negative,non-spore-formingrodswhosenaturalhabitatistheintestinaltractofhumansandanimals,alsoincludingwater,soiletc.II.CommonpropertiesofEntericbacilli1.G-rods,distributedintheintestinaltractofhumans(including44genera,170+species)normalflora---Escherichiacolipathogenic---Salmonellae,Shigellaeopportunisticinfection---2.Non-spore-forming,mostofthempossessedflagella(motile),pili3.Lowerrequirementofnutrition,usuallyusedselectivemedia:S-Splate4.Activebiologicalreaction,especiallyforfermentativeSugar

MobileLactoseurea

E·coli++－

Salmonella+－－

Shigella

－－－

Proteus+－+

Fivesugarsfermentation

glucoselactosemalosemannitolsucroseE.Coli

-/

Shigella+-+++S.Typhi+-++-paratyphiA-+-paratyphiB-+-

5.ComplexantigenicstructuresOantigen:

LPSHantigen:ProteinsCapsuleorenvelopeantigen:polysaccharide

E.coli---KantigenSalmonella---Viantigen{

鞭毛抗原（H）菌体抗原（O）K或Vi抗原others：

piliAgECA6.Commongenus1)Escherichia:E.coli2)

Klebsiella:K.pneumoniea3)Proteus:P.vulgaris

4)Acinebacter:A.baumannii

EscherichiaColi(E.Coli)

I.BasicProperties1.G-.Flagella+,pili+2.S-Sagarplate:RedColony,untransparentResultonS-Splate3.Fivesugarsfermentation

glucose,Lactose,maltose,mannitol,sucrose

IMViC

E.Coli:++－－

E.aerogen:－－++4.Antigenstructure:formula---O:K:HOAg:>170KAg:>100HAg:>60II.PathogenisisOpportunitisticinfection:

PathogenicE.Coli:1.

Pathogenicfactors

1)Colonizationfactor(adhesin):pili,KAgpili---7kinds2).Toxins:

4kindstoxins:Shigatoxin

heatlabiletoxinheatstabletoxinhemolysinA

Enterotoxin(Exotoxin)HeatLabileerterotoxin(LT):ATPcAMP

over-secretionHeatstableenterotoxin(ST):GTPcGMP

lower-absorption1A+5Bsubunits,MW80000MW1500-40002

Diseases

1).infectioninoutsideofintestinaltract

(1)Septicemia(1st,S.aureus,CNS)(2)Meningitisininfant:E.coliandGBS(B群链球菌)(3)Infectioninurinarytract:UPEC(4)Pyogenicdiseases:peritonitis(腹膜炎),cholecystitis(胆囊炎),pyelitis(肾盂炎).

2).infectioninintestinaltract(diarrhealdiseases)(1)

enterotoxigenicE.coli,(ETEC)

LT(cAMP),ST(cGMP)

traveler’sdiarrhea,babies,children(2)

enteropathogenicE.coli

,(EPEC)

withoutproductionofenterotoxininvadesuperficialintestinalepitheliumthemostcommondiarrheaininfants(3)

enteroinvasiveE.coli

,(EIEC)

withoutenterotoxinchildrenandadultsdiarrhea(4)

enterohemorrhagicE.coli

,(EHEC)

produceVerotoxin.mostsevere,suchasHUS

O157:H7

seeattachedfile—toxiccucumber!EnteroaggreativeE.coli

,(EAECorEaggEC)

chronicdiarrhea(>14days)III.Diagnostictests1.forpathogenicbacteria1).Specimen:urine,stool,blood,pus.2).isolationandidentification:(1)fecesS-SplateobservethecoloniesandGramstain(2)bloodbrothS-Splate

(3)Biochemicalreaction.IMViC,5-sugarfermentation,(4)Double-Sugarironmedium.

components:0.1%glucose,1%lactose,IronSalt,Phenolred

Results:allbecameyellow;bulb;H2S(-)(5)Semi-solidmedia:Forbacterialmotility(6)SerologicaltestPolyvalentantiserumMonovalentantiserum

(forspecies)(fortyping)(7)Animaltestandtissueculture:Animaltestisusefulforenterotoxin，ButnowELISAisusedcommonlyTissueculture(Hep-2)isusefulforEPEC

2.Hygienictests1).Totalofbacteria.(Livingbacteria)2).E.coliindex.TubesofLactosefermentation.

Hygienicstandard(inwater):

index<3colonies/1liter.

total<100bacteria/1mlor1gShigella(dysenterybacterium)Ⅰ.Importantproperties

G-,rod

noflagellumglucose(+),lactose-fermenting(-),noteDgroup

Oantigen:4groups---A、B、C、DKantigenantigenDoublesugarsandironmedia&motilitytestA.E.coliB.ShigellaC.negativecontrol

Groupsbasedon“O”antigen

Groupdesignationtypesub-type

AS.dysenteriaeA1-A108a,8b,bcBS.flexneriB1-B6,1a,1b,2a,2b,3ax,y3b,3c,4a,4bCS.boydiiC1-C18DS.sonneiD1Resistance:weaker,butstrongtoantibioticsandbilesaltaswellasethylgreenⅡ.Pathogenesisandimmunity

morbidityin5,mortalityin101.Principalfactors:a.invasion(rareintoblood)pili---Mcell---typeⅢsecretionsystem---endocytosis---intocells

b.endotoxin:absorbtion:fever,toxicshock,DIClocalinflammation:bloodydiarrheasympatheticnerve:strainingandtenesmus

c.enterotoxin(Shigatoxin,ST)

produce---Agroupbacteria

toxicity:enterotoxicity,neurotoxicity,

cytotoxicity(StxAandStxB,

blockproteinsynthesisi

)

2.Diseases:Fecal-oraltransmission1).AcuteDysentery:fever,diarrhea(lessliquid,containingmucusandblood,strainingandtenesmus)

ToxicDysentery:fever,shock

2).ChronicDysentery:>2months

3).

Carrier:fewer3.Immunity:sIgA,notsrong,persistingshorttimeⅢ.MicrobiologicalDiagnosisStoolswabs-sagarplatepickup

smalltransparent

semisolidagar

colorlesscolonies

doublesugarironagargram’sstainbiochemicaltestserologicaltest*therapidtest:IFA,Coagglutinaion

Ⅳ.Principlesofpreventionandtreatment

1.Prevention:

1)payattentionto4F:food,fingers,

feces,flies

2)treatmentofpatientsand

contaminatedmaterials

3)discoverycarriers

4)oralvaccine:Sdstrain

2.Treatment:

antibiotics(ciprofloxacin,tertracyclin,

ampicillin,chloramphenicol)Salmonella

2species:S.enterica,S.bongori

>2500types,mostoftheminS.entericaI.Importantproperties

G-rod;pili;flagellanon-fermentlactoseproduceH2S

antigen:seethetableS-S

plate：SS平板分离培养SS平板纯培养大肠杆菌：较大的红色、浑浊的菌落伤寒杆菌：较小的半透明的淡黄色或无色菌落，部分菌落中心有黑色沉淀MainbiochemicalreactionsofSalmonella++++++++++++++++++Antigenstructure:seethetableAntigenictypelocationpropertiesserotypeAntigenicityspecificityOantigenCellwallLPS,Heatstable42groups:A,B,C,D…..Weakly,Low,IgM(earlier)HantigenflagellaProtein;HeatlabilePhaseⅠ:a,b,c…PhaseⅡ:1,2,3…Strong,high,IgG(late,long)ViantigenCapsule,Poly-saccharidesHeatlabileWeakly，Relatedvirulence，ViAbResistance:weakly,butstrongtobilesaltaswellasethylgreenⅡ.pathogenesis1.Principalfactors:

a.invasion:pili;Vi-antigen

Mcells---typeⅢsecretionsystemand

acidtoleranceresponse

b.endotoxin:Fever,shock,but

WBCdecreased

c.exotoxin:S.typhimurium,likeLT2.Diseases:a.entericfevers(typhoidfever)

theorganismsentermultiplyinthemononuclearphagocytes,throughlymphatics

leadstobacteremiaproduceendotoxinpersisitantfever+othersymptom:spleenandliverenlarged,WBC,RosespotChiefcomplication:intestinalperforation(2timesbacteremia)b.Enterocolitis(foodpoisoning):

themostcommon,about70%,0.1billionbacteria

bacteria:S.typhimurium,S.choleraesuisc.Septicemia:

bacteria:S.choleraesuis,S.hirschfeldiid.Carrier:onlyafew(1%-5%)

commoninolder,femaleⅢ.ImmunityCellularimmunityVerystrongPersistinglongtime,reinfectionrarelyoccurⅣ.LabDiagnosis

1.Isolationandindentificationoforganism:

samples,thensameasShigellaSamplestakenfromillnesscourseProcessforbloodsample需氧培养传统方法或自动血液培养仪指示有菌生长血液标本（无菌采集）厌氧培养增菌培养直接涂片染色镜检需氧培养及CO2培养血平板分离培养直接药敏试验厌氧培养挑选可疑菌落纯培养直接涂片染色镜检药敏试验血清学试验生化反应报告粪便标本SS琼脂平板培养基Processforstoolsample报告可疑菌落直接涂片染色镜检KIA、IMViC、MIU药敏试验血清学鉴定其他生化鉴定Typhiandptyphienterocolitissepsis

1wblood food,vomitingblood

1-3wbonemarrow

~2wfeces,urine

MicrobecheckpathogenSpecimenS-SplateBiochemicalSerologicaldoublesugarsandiron

Slideaggulination

2.Widaltest:Concept:Method:S.typhiOAgHAgS.paratyphiA,B,CHAgResults:a.normallevelofAbb.earlierVSlatetiter:>4timesSeethefileattachedattheend!c.OAbandHAb

OAbHAb3.Carrierstate

V.Principlesofpreventionandtreatment

1.Prevention:

1)payattentiontowater,milkanddairyproducts

2)treatmentofpatientsand

contaminatedmaterials

3)discoverycarriers:Anti-Vi

4)oralvaccine:Ty21a,Vi

2.Treatment:

antibiotics(ampicillin,chloramphenicol)复习思考题肠道杆菌的共同特点是什么？归纳志贺菌致病的主要特点。急性菌痢的典型症状有哪些?解释其形成机制。什么是肥达试验？如何进行结果判定?简述肠道菌粪便标本分离鉴定的流程。中英文关键词Escherichia埃希菌属E.coli大肠埃希菌ETEC肠产毒型大肠埃希菌EPEC肠致病型大肠埃希菌EAEC肠集聚型大肠埃希菌EIEC肠侵袭型大肠埃希菌EHEC肠出血型大肠埃希菌heatstableenterotoxin(ST)耐热肠毒素heatlabileenterotoxin(LT)不耐热肠毒素Shigella志贺菌属S.dysenteriae痢疾志贺菌S.flexneri福氏志贺菌中英文关键词S.boydii鲍氏志贺菌S.sonnei宋内志贺菌Shigatoxin志贺毒素Salmonella沙门菌属S.typhi伤寒沙门菌S.

paratyphiA甲型副伤寒沙门菌S.schottmuelleri肖氏沙门菌S.hirschfeldii希氏沙门菌S.typhimurium鼠伤寒沙门菌S.choleraesuis猪霍乱沙门菌S.enteritidis肠炎沙门菌Widaltest肥达试验课外阅读资料目录[1]PenningtonH.,EscherichiacoliO157.Lancet.2010Oct23;376(9750):1428-35.[2]TarrPI,GordonCA,ChandlerWL.Shiga-toxin-producingEscherichiacoliandhaemolyticuraemicsyndrome.Lancet.2005Mar19-25;365(9464):1073-86.[3]AshidaH,OgawaM,MimuroH,KobayashiT,SanadaT,SasakawaC.Shigellaareversatilemucosalpathogensthatcircumventthehostinnateimmunesystem.CurrOpinImmunol.2011Aug;23(4):448-55.[4BarrowPA,JonesMA,SmithAL,WigleyP.Thelongview:Salmonella-thelastfortyyea