牛源大肠杆菌O157∶H7的分离鉴定及其生物学特性研究  

Isolation and identification of Escherichia coli O157∶H7 from cow and its biological characteristics

作　　者：程慧芳[1] 寇亚楠[1] 陈雅君[1] 刘中原[1] 张龙现[1,2] 王亚宾[1] 陈丽颖[1] 胡慧[1,2] 

机构地区：[1]河南农业大学牧医工程学院,郑州450002 [2]河南省人兽共患病国际联合实验室,郑州450002

出　　处：《中国人兽共患病学报》2014年第10期1002-1008,共7页Chinese Journal of Zoonoses

基　　金：郑州市食源性病原体监测重点实验室平台项目(114PYFZX509);国家质检总局科技计划项目(2013QK233)~~

摘　　要：目的为了解郑州地区牛携带大肠杆菌O157∶H7的情况。方法应用本实验室已建立的大肠杆菌O157∶H7多重PCR方法对其进行了检测,并对临床分离的动物源大肠杆菌O157∶H7的生物学特性及携带的毒力基因情况进行了分析。结果所采集的样品中共分离鉴定出2株大肠杆菌O157∶H7,分别命名为L1和L2,其检出率为1.4%;临床分离菌株的生化试验结果均符合大肠杆菌的常规生化特性;L1和L2菌株的生长曲线一致,均比标准株的迟缓期短,较早进入对数生长期;L1菌株在48h可形成成熟完整的生物被膜,L2菌株在36h形成成熟完整的生物被膜;L1和L2菌株均携带有hlyA和eaeA毒力基因,同时L1还携带Stx2毒力基因。结论该结果为大肠杆菌O157∶H7流行病学调查提供了相关数据,对郑州地区大肠杆菌O157∶H7有效的监测奠定了基础。To understand the Escherichia coli （E .coli） O157∶ H7 isolated from cow in Zhengzhou ,Henan Province ,a total of 146 samples of cow fecal and milk were collected in the different farms ,and E .coli O157∶ H7 was detected with mul-tiplex polymerase chain reaction （PCR） in our laboratory .Then the biochemical characteristics ,growth dynamic ,the biofilm formation ,and the toxin genes of the E .coli O157∶ H7 isolates were analyzed .The results showed that 2 strains of E .coli O157∶H7 were found ,with the detection rate of 1 .4% ,and the isolates were named as L1 and L2 in current study ,respec-tively .The E .coli O157∶H7 clinical isolates had the same biochemical characteristics with that of the typical E .coli .The L1 and L2 isolates presented similar growth curve ,which entered into the log phase earlier than that of the standard strain .L1 strain formed thick ,confluent ,complete biofilm after 48 hours post-inoculation ,and the biofilm of L2 strain was formed com-pletely in 36 hours .The two E .coli O157∶ H7 isolates were positive with eaeA and hlyA genes ,and the L1 strain also carried the Stx2 virulence gene .Our results reinforce the epidemiological data of E .coli O157∶H7 ,and underscore the need for more effective surveillance of animal-derived E .coli O157∶H7 isolates in Zhengzhou City ,China .

关 键 词：大肠杆菌O157 H7 分离鉴定 多重PCR 生长曲线 生物被膜 

分 类 号：S855.1[农业科学—临床兽医学]