大肠杆菌O157∶H7菌毛hcpA基因产物的小鼠免疫保护试验(英文)  

Immunoprotection of recombinant hcp A protein from enterohemorrhagic Escherichia coli O157∶H7 in mice

作　　者：张雪寒[1] 何孔旺[1] 叶青[1] 倪艳秀[1] 温立斌[1] 李彬[1] 周俊明[1] 王小敏[1] 

机构地区：[1]江苏省农业科学院兽医研究所/农业部兽用生物制品工程技术重点实验室/国家兽用生物制品工程技术研究中心,南京210014

出　　处：《中国人兽共患病学报》2012年第11期1065-1070,1101,共7页Chinese Journal of Zoonoses

基　　金：Financially supported by the National Science&Technology Pillar Program(No.2012BAK08B07);the National Natural Sciences Foundation of China(No.31201919)~~

摘　　要：最近鉴定的大肠杆菌O157∶H7Ⅳ型菌毛(HCP)与细菌粘附、定植和致病有着密切关系。本文研究表明,PCR扩增出15个大肠杆菌O157∶H7分离株HcpA基因,透射电镜观察到HCP表达于菌体表面。同时,构建BL21(pET32-hc-pA)重组菌,成功表达重组蛋白His-HcpA。His-HcpA免疫家兔制备高滴度(1∶12800)多克隆抗体,Western blot显示能够与HCP菌毛蛋白反应。Balb/c小鼠分别在0周和第3周皮下接种His-HcpA,和对照组小鼠相比,获得70%存活率,并且排菌量降低,排菌时间缩短。本研究表明,His-HcpA具有良好的免疫原性,是大肠杆菌O157∶H7重要的毒力因子。The recently-identified hemorrhagic coli pilus(HCP) gene in E.coli O157∶H7has been shown to be involved in bacterial adherence,colonization and pathogenesis.In this study,hcpA genes were detected in fifteen O157∶H7isolates by PCR,and the expression of this type IV pilus was observed by electron microscopy.Meanwhile,the hcpA gene was cloned,and its recombinant HcpA protein was expressed in BL21(DE3) cells.High-titer polyclonal antibodies(1∶12 800) were prepared with His-tagged HcpA protein in immunized rabbits,thus,the immunogenicity of HCP was analyzed by Western blotting assay.Balb / c mice subcutaneously inoculated with purified His-HcpA protein were challenged by O157∶ H7 strains,resulting 70% protection rate and reduced fecal shedding in comparison to naive mice.The observation suggests that the recombinant His-tagged HcpA has considerable immunogenicity in a mouse model,and that HCP is a potential virulent component in E.coli O157∶H7.

关 键 词：肠出血性大肠杆菌O157∶H7 Ⅳ型菌毛 表达 排菌 

分 类 号：R378[医药卫生—病原生物学]