医学微生物课件.ppt

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1、Chapter11bacterialinfectionInfection感染TheprocessofinterplaybetweenM.andhost.M.HostdefensesDifferentresultsafterinfectionPathogen:Amicroorganismcapableofcausingdisease.Nonpathogen:Amicroorganismthatdoesnotcausedisease.Opportunisticpathogen条件致病菌:somenon-pathogensmaycausediseasesundersomespec

2、ialconditions.Section1normalmicrobialfloraandopportunisticB.1.Normalflora正常菌群ThevariousB.andF.thatarepermanentresidentsofcertainbodysitesvaryinnumberandkindfromonesitetoanotherthelocationsareusuallyskin,oropharynx,colon,andvagina(mucousmembranes)肠道的正常菌群健康青年粪便涂片健康壮年粪便涂片健康中年粪便涂片鼻咽腔葡萄球菌、甲，丙型链球菌

3、肺炎球菌、奈氏菌、类杆菌等外耳道葡萄球菌、类白喉杆菌绿脓杆菌、非致病性分枝杆菌表皮葡萄球菌口腔甲，丙型链球菌类白喉杆菌、肺炎球菌奈氏菌、乳杆菌、梭杆菌螺旋体、放线菌、白念珠菌肠道大肠杆菌、产气杆菌、变形杆菌绿脓杆菌、葡萄球菌、厌氧性细菌真菌、乳杆菌，双歧杆菌等阴道大肠杆菌、乳杆菌白念珠菌、类白喉杆菌非致病性分枝等皮肤葡萄球菌、绿脓杆菌、白念珠菌丙酸杆菌、类白喉杆菌、非致病性分枝杆菌人体内正常菌群的分布眼结膜白色葡萄球菌、干燥杆菌尿道白色葡萄球菌、类白喉杆菌、非致病性分枝杆菌RoleofnormalflorakeephealthCausedisease2.beneficialef

4、fectsofthenormalfloraPrimingofimmunesystemplayanimportantroleinthedevelopmentofimmunologiccompetenceInducecross-reactionwithpathogenicorganismsexclusionaryeffect生物拮抗---colonizationresistanceProductionofessentialnutrients----produceseveralBvitaminsandvitaminK3.opportunisticB.条件致病菌Manyspeciesa

5、mongthenormalfloraareopportunists.Memberofthenormalfloramaythemselvesproducediseaseundercertaincircumstances.threeconditionscorrelatedwithopportunisticinfectionImmunesystemcompromiseDysbacteriosis菌群失调ChangeofinhabitingplacesdysbacteriosisWhentheresidentfloraisdisturbed,somelittlesignificantM

6、.maycolonize,proliferateandproducediseases.Mainlyresultfromlongtermandlargedosesantibioticstakennosocomialinfections医院获得性感染definitionAnyinfectionacquiredwhileinhospitalsourcesHospitalpersonnelEnvironmentMedicaldevices医疗用具BloodandbloodproductsSection2bacterialpathogenesisPathogen病原菌:haveth

7、ecapacitytoinitiatediseasesPathogenicity致病性:thecapacityofB.toinitiatediseases致病性毒力侵入数量侵入途径侵袭力毒素荚膜、微荚膜黏附素侵袭性物质内毒素外毒素表面结构鞭毛生物被膜侵袭性酶侵袭素virulence毒力:AquantitativemeasureofpathogenicityLD50:thenumberneededtokillhalfthehostsID50:thenumberneededtocauseinfe