我国分离的大肠埃希菌O157∶H7的毒力基因检测分析  

Virulent genes of Escherichia coli O157∶H7 strains isolated from China

作　　者：王涛[1] 刘丽云[2] 王娉[2] 熊衍文[2] 白雪梅[1] 叶长芸[2] 徐建国[2] 

机构地区：[1]贵阳医学院微生物学教研室,贵阳550004 [2]中国疾病预防控制中心传染病预防控制所,传染病预防控制国家重点实验室,北京102206

出　　处：《中国人兽共患病学报》2010年第6期515-518,共4页Chinese Journal of Zoonoses

基　　金：国家科技部“973”项目(No.2005CB522904)资助

摘　　要：目的了解我国部分省区分离的大肠埃希菌O157∶H7菌株特异基因和毒力基因携带特点及在不同动物宿主来源的菌株分布情况。方法采用PCR对分离菌株的O157、H7抗原特异基因rfbEO157、fliCH7以及stx1、stx2、eaeA和hlyA四种毒力基因进行检测。结果在1992-2006年收集的O157及H7抗原阳性的345株大肠埃希菌株中,rfbEO157、fliCH7特异基因均为阳性,eaeA和hlyA的阳性率分别为99.4%和99.1%,stx2的阳性率为91.9%,stx1阳性率仅为13.3%,stx1+stx2的阳性率为13.0%,来源于病人和动物菌株的stx2阳性率均高于stx1。检测菌株中毒力基因型以eaeA+hlyA+stx2为主。携带毒力基因的O157∶H7菌株在羊、牛等动物宿主中广泛存在。结论 stx2是病人及羊、牛等动物来源的产志贺毒素大肠埃希菌O157∶H7携带的主要毒素基因型。To understand the specific genes and virulent genes profiles of the O157∶H7 strains isolated from China and the distribution in different host animal.PCR was used to identify the specific rfbEO157,fliCH7 genes and virulent genes of stx1,stx2,eaeA and hlyA.The specific rfbEO157,fliCH7 genes were found in all of the 345 strains of E.coli O157∶H7 isolated from 1992 to 2006 in China.99.4% and 99.1% of the tested strains were positive for eaeA and hlyA respectively.91.9 % strains carried stx2 gene.Only 13.3% strains carried stx1 gene,but 13.0% strains carried both stx1 and stx2.The positive rate of stx2 was much higher than that of stx1 in strains isolated from patients and animals.eaeA＋hlyA＋stx2 was the dominant virulent genotype.The Escherichia coli O157∶H7 strain that carried virulent genes is widely present in goat,cattle and other animal hosts.The results demonstrates that stx2 is the dominant virulent gene of Shiga toxin-producing E.coli O157∶H7 isolates from patients and animals.

关 键 词：大肠埃希菌O157∶H7 毒力基因 检测 

分 类 号：R378.2[医药卫生—病原生物学]