成都市武侯区肉类食品大肠杆菌污染状况及毒力基因调查

Investigation of Escherichia coli contamination and virulence genes in meat foods from Wuhou district of Chengdu city

了解成都市武侯区肉类食品中大肠杆菌污染情况和分离菌株的毒力特征,以预防和控制食品污染,保证食品安全。2011~2013年间采集成都市武侯区超市和菜市场的肉类食品,经选择性培养与分离鉴定,采用PCR方法检测8种相关毒力基因（eae A、stx1A、stx2A、hly A、agg R、est、elt A和bfp A）的流行情况。结果表明生肉类中大肠杆菌的检出率为81.07%,熟肉类中大肠杆菌的检出率为40%;在分离的324株大肠杆菌中有49株检测到一种及以上毒力基因;主要流行的毒力基因是eae A和agg R,未检测到est和bfp A基因。通过本研究发现成都市武侯区肉类食品中大肠杆菌污染比较严重,大肠杆菌携带毒力基因以eae A和agg R为主,该结果反映本市肉类产品的卫生安全状况,可为成都地区食品源大肠杆菌控制及毒力基因流行提供科学数据。

The contamination of Escherichia coli in meat foods of Chengdu city and virulent characteristics of isolated strains were investigated in this study,which could lay basis for preventing and controlling of E. coli contamination in food and guaranteeing food safety. Meat samples were collected from the supermarkets and retail markets located in Wuhou district of Chengdu city from 2011 to 2013. These samples were enriched and E. coli strains were isolated and identified. DNA of all the isolated strains were extracted and subjected to PCR detection for eight virulence genes（eae A,stx1 A,stx2A,hly A,agg R,est,elt A and bfp A）. The detection rate of E. coli for raw meat samples was 81.07%,and the detection rate of E. coli for cooked meat samples was 40%.49 strains were detected to having more than one virulence genes from 324 isolated E. coli strains. The main prevalent virulence genes were eae A and agg R,while est and bfp A genes could not be detected. The contamination of E. coli in meat samples was found to be very high. These results would provide significant data for the control and survey of foodborne E. coli in meat samples.