某牛场粪源大肠杆菌O157∶H7的分离鉴定

Isolation and Identification of Manure Source Escherichia coli O157∶H7 From a Cattle Farm

为了解重庆市某牛场牛群大肠杆菌O157∶H7的感染情况,我们以牛场犊牛为研究对象,采集其新鲜粪便,经LB培养基增菌培养、免疫磁珠富集后,在山梨醇麦康凯琼脂上划线培养,最后PCR扩增eae A基因目的片段,以此分离鉴定粪源大肠杆菌O157∶H7。结果显示:在所采集的39份犊牛粪便样品中,分离得到一株符合大肠杆菌O157∶H7生长特点且含有eae A基因的菌株。

In order to understand the E.coli O157：H7 infectious status of a cattle herd in Chongqing, fresh droppings of calves were collected to incubate on LB medium. The E.coli O157：H7 on sorbitol MacConkey agar streak cultured after seperating by immunomagnetie sand method. Finally, eaeA gene fragment was amplified by PCR to ensure the isolation and identification of E.coli O157： H7 in accuracy. The result showed that there was one strain which consistent with growth characteristics of E.coli O157：H7 and containing eaeA gene in all 39 faeces samples.