广东地区大肠杆菌O157∶H7的分离与鉴定

Isolation and identification of Escherchia coli O157:H7 in Guangdong Province

目的了解广东地区家畜、肉菜市场及屠宰场中动物、动物源性食品原材料中大肠杆菌O157H7的分布及这些细菌对常用抗菌素的敏感性。了解这些细菌对小白鼠的致病力。方法样品采集送实验室后,接种mEC+n肉汤培养基中于41℃增菌24h,取增菌液接种CTSMAC平板,37℃培养24h,挑取可疑菌落,经血清学检验、微量生化实验初步确认。再用5重PCR对它们进行基因检测确认。然后在小白鼠中进行毒性试验;用药敏试纸测试它们对常用抗菌素的敏感性。结果共检查猪、牛粪便、猪肉样品及肝肺拭子样品共774份,检出4株O157H7,检出率052%;对分离菌株作药物试验,发现菌株对四株素,链霉素、青霉素、磺胺类等存在不同程度的耐药。结论我们首次对广东省作O157H7较全面的调查,分离出4株O157H7。

In order to insure the food safety and make clear the distribution of Escherchia coli O^157 :H7 in Guangdong Province, the collected samples were cultured in mEC+n broth, at 41℃ for 24hours, and the enriched cultures were cultivated on CT-SMAC plates at 37℃ for another 24 hours. The suspicious bacterial growth on the plates were preliminarily identified by serological testing and micro-biochemical reactions, and then definitely confirmed by means of multi-PCR. It was found that 4 strains of E.coli O157:H7 from 774 samples from bovine feces. Pork samples and swabs from liver and lung (detection rate 0.52%).These strains exhibited certain degrees of drug-resistance to tetracycline, streptomycin, penicillin and sulfonamides.