Medical MicrobiologyDepartment of Microbiology, HMUDepartment of Microbiology, HMU第二篇 致病性细菌第14章埃希菌属Escherichia微生物学教研室微生物学教研室 张文莉张文莉教学大纲n n熟悉uu肠道杆菌的共同特征及分类肠道杆菌的共同特征及分类uu致病性大肠埃希菌的种类和致病机制致病性大肠埃希菌的种类和致病机制n n掌握uu大肠埃希菌的卫生细菌学检查及其意义大肠埃希菌的卫生细菌学检查及其意义n n了解uu大肠埃希菌的微生物学检查法大肠埃希菌的微生物学检查法Department of Microbiology, Harbin Medical University问题n n大肠埃希菌与人类健康的关系如何？n n肠道杆菌的共同特征？Department of Microbiology, Harbin Medical University形态染色n n0.4-0.7m 1-3m n n短杆菌n n革兰染色阴性n n有鞭毛n n有菌毛Department of Microbiology, Harbin Medical UniversityDepartment of Microbiology, Harbin Medical University培养特性与生化反应n n兼性厌氧n n营养要求不高n n生化反应活泼，发酵多种糖类n n绝大多数发酵乳糖n nIMViC试验结果为+ + - -Department of Microbiology, Harbin Medical University大肠埃希菌于普通营养平板培养生长的菌落Department of Microbiology, Harbin Medical University抗原结构n nO抗原：菌体抗原n nH抗原：鞭毛抗原n nK抗原：荚膜抗原n nO111：K58：H2Department of Microbiology, Harbin Medical University复杂的抗原构造Department of Microbiology, Harbin Medical University致病物质n n菌毛、定居因子抗原n nK抗原 uu与侵袭力有关与侵袭力有关uu抗吞噬与抗补体的溶菌抗吞噬与抗补体的溶菌n n外毒素 uu肠毒素及溶血毒素肠毒素及溶血毒素n n内毒素uu与感染特征和严重程度有关与感染特征和严重程度有关Department of Microbiology, Harbin Medical University所致疾病n n肠道外感染 uu泌尿道感染最多见泌尿道感染最多见 uu化脓性感染化脓性感染n n腹泻Department of Microbiology, Harbin Medical University引起腹泻的大肠埃希菌n n肠产毒型大肠埃希菌肠产毒型大肠埃希菌 enterotoxigenicenterotoxigenic E. coliE. coli ETECETECn n肠侵袭型大肠埃希菌肠侵袭型大肠埃希菌 enteroinvasiveenteroinvasive E. coliE. coli EIECEIECn n肠致病型大肠埃希菌肠致病型大肠埃希菌 enteropathogenicenteropathogenic E. coliE. coli EPECEPECn n肠出血型大肠埃希菌肠出血型大肠埃希菌 enterohemorrhagicenterohemorrhagic E. coliE. coli EHECEHECn n肠集聚型大肠埃希菌肠集聚型大肠埃希菌 enteroaggregativeenteroaggregative E. coliE. coli EAggECEAggECDepartment of Microbiology, Harbin Medical University肠产毒素型大肠埃希菌（ETEC）n n致病物质uu肠毒素肠毒素uu菌毛粘附素菌毛粘附素uu内毒素内毒素uuK K抗原抗原n n所致疾病uu5 5岁以下婴幼儿腹泻岁以下婴幼儿腹泻uu旅游者腹泻旅游者腹泻Department of Microbiology, Harbin Medical UniversityDepartment of Microbiology, Harbin Medical UniversityDepartment of Microbiology, Harbin Medical UniversityDepartment of Microbiology, Harbin Medical University肠侵袭型大肠埃希菌（EIEC）n n致病物质uu不产肠毒素，侵袭结肠粘膜上皮细胞不产肠毒素，侵袭结肠粘膜上皮细胞n n所致疾病uu主要侵犯较大儿童和成人主要侵犯较大儿童和成人uu腹泻呈脓血便，有里急后重诊断腹泻呈脓血便，有里急后重诊断uuEIECEIEC无动力、生化反应和抗原结构无动力、生化反应和抗原结构Department of Microbiology, Harbin Medical UniversityDepartment of Microbiology, Harbin Medical University 肠致病型大肠埃希菌（EPEC ）n n致病物质uu不产生肠毒素及其他外毒素不产生肠毒素及其他外毒素uu无侵袭力无侵袭力n n所致疾病uu婴幼儿腹泻婴幼儿腹泻Department of Microbiology, Harbin Medical University肠出血型大肠埃希菌（EHEC）n n亦称为vero毒素大肠埃希菌 n n致病物质uu菌毛：粘附作用菌毛：粘附作用uu毒素：毒素：verovero毒素毒素n n所致疾病uu出血性结肠炎出血性结肠炎uu溶血性尿毒综合征溶血性尿毒综合征Department of Microbiology, Harbin Medical UniversityIntimate Adherence of EHEC to Epithelial CellsDepartment of Microbiology, Harbin Medical UniversityThe “life cycle” of E. coli O157:H75-10% prevalence in animals5-10% prevalence in animals40% prevalence in farms40% prevalence in farmsDepartment of Microbiology, Harbin Medical University 肠集聚型大肠埃希菌 EAggECn n致病物质uu毒素毒素uu粘附素粘附素n n所致疾病uu引起婴儿持续性腹泻，脱水，偶有血便引起婴儿持续性腹泻，脱水，偶有血便Department of Microbiology, Harbin Medical University肺泡巨噬细胞吞噬大肠埃希菌Department of Microbiology, Harbin Medical University 微生物学检查法n n标本 n n分离培养与鉴定uu肠道外感染肠道外感染uu肠道内感染肠道内感染 Department of Microbiology, Harbin Medical University卫生细菌学检查n n大肠菌群指数uu每每1000(1000(g)g)ml水中大肠菌群数uu大肠菌群大肠菌群n n细菌总数 uu每每1 1ml(g)样品中细菌总数n n我国卫生标准uu大肠菌群大肠菌群uu细菌总数细菌总数Department of Microbiology, Harbin Medical University防治原则n n疫苗n n抗生素的抗性质粒，耐药性非常普遍Department of Microbiology, Harbin Medical University小结n n肠道杆菌的共同特征及分类n n致病性大肠埃希菌的种类和致病机制n n大肠埃希菌的微生物学检查法n n大肠埃希菌的卫生细菌学检查及其意义Department of Microbiology, Harbin Medical University