浙江省衢州市柯城区检出带毒力基因的肠出血性大肠埃希菌O157:H7

EHEC O157:H7 with virulence gene detected in Kecheng district,Quzhou city,Zhejiang province

目的了解浙江省衢州市柯城区肠出血性大肠埃希菌O157:H7人的感染、食品污染以及动物和媒介昆虫带菌情况。方法采集腹泻患者粪便、动物粪便以及各类食品、蝇类等标本,MEC肉汤增菌后,用特异性免疫磁珠集菌,以科玛嘉显色平板分离,纯化的菌株经生化鉴定、血清分型及毒力基因检测。结果2007年采集动物粪便标本300份,共检出O157:H7菌16株,总带菌率为5.33%,其中牛、羊、猪带菌率较高,分别为20.83%、12.70%和3.61%,腹泻患者、食品和媒介昆虫中均未检出。毒力基因检测所有分离株stx2、hly、eaeA3种毒力基因均呈阳性,而stx1均呈阴性。结论衢州市柯城区部分动物中存在O157:H7感染,且为产毒株,应加强O157:H7的综合监测。

Objective The study was conducted to investigate the human infection, food contamination, and bacteria-beating of animal and insect vectors of enterohemorrhagic Escherichia coli O157：H7 in Quzhou, Zhejiang. Methods Diarrhea patient and animal stool samples, various food samples and fly samples were cultured in MEC broth, amassed with immunomagnetie separation, and isolated in CHROMAGAR-O157：H7 culture medium. Purified isolates were biochemically identified, serotyped and detected for virulence genes. Results A total of 300 animal stool samples were collected in 2007, and 16 strains of O157：H7 were isolated with the overall positive rate of 5.33%. The positive rates of bacteria beating cattle, sheep and pig were 20.83%, 12.70% and 3.61%, respectively. No O157：H7 were isolated from the samples of diarrhea patients, food and insects. PCR results showed that stx2, hly and eaeA were positive and stxl was negative in all isolates. Conclusion Some animals in Kecheng county, Quzhou city were infected by toxin-producing E.coli O157：H7. Therefore comprehensive surveillance for O157：H7 is required.