肠道杆菌和弧菌（精品）

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1、i.Enteric肠道的Gram-NegativeRods&ii.Vibriocholerae霍乱弧菌i.EntericGram-NegativeRods(Enterobacteriaceae肠杆菌)TheEnterobacteriaceaearealargeheterogenousgroupofgram-negativerodswhosenaturalhabitatistheintestinaltractofhumansandanimals.Thefamilyincludesabout29genera,over100species:EscherichiaShigellaSalm

2、onellaCitrobacterKlebsiellaEnterobacter肠杆菌属Yersinia克雷伯氏菌属柠檬酸细菌属耶尔森氏菌属Someoftheentericbacilli(e.g.,Escherichiacoli)arepartofthenormalfloraandmajorcausingagentofopportunisticinfection.SalmonellaeandShigellaearepathogenicforhumans.GeneralcharacteristicsAllbacillibelongingtoEnterobacteriaceaeares

3、hortGram-negativerods,eithermobileornon-mobile,nospore,somehavecapsulesandpili.Size:0.4X3μmGeneralcharacteristicsAllbacillibelongingtoEnterobacteriaceaearefacultativeanaerobesoraerobes.Theygrowincommonmedia.Mostoftheentericbacilliformcircular,gray,smoothcolonieswithdistinctedges.lactosefermen

4、tation乳糖发酵Mechanism:Non-pathogenicentericbacilliareabletofermentlactosewhilepathogenicentericbacillisuchasShigellaandSalmonellaarenot.Basiccomponents:lactoseandapHindicatorlactosefermentationResultscoloredcolonies(red)non-pathogenicyesnowhitecoloniespathogenicUsetodifferentiatenon-pathogenicE

5、.ColifrompathogenicShigellaandSalmonella--SSagarplatelactoseDoublesugarironagarslants:containsglucose,lactose,ironacetate醋酸亚铁andpHindicator.Results:hydrogensulfide(H2S)+-lactosefermentationGeneralcharacteristicsEnterobacteriaceaehavecomplexantigenicstructuresH(flagellar)AgsomaticOAg(lipop

6、olysaccharide)K/Vi(capsular)AgGeneralcharacteristicsCommonpathogenicmaterialsforEnterobacteriaceaeinclude:bacterialstructures(flagella,capsules)toxins(enterotoxin,endotoxin)Escherichiacoli大肠埃希菌MorphologyandidentificationGramnegativebacillusMotilewithflagellaRedcoloniesonSSagarmediummoststrain

7、sfermentlactoseproductionofacidandgaswithin24~48hAntigens:O-Ag,H-Ag,K-AgIMViC:++――Transmissionisbyfecal-oralroute.Virulencefactorsinclude:Flagella:induceadhesionCytotoxicenterotoxins:causediarrhea(sometimeswithblood)andtissuedamage.Invasionfa