105株携带耶尔森菌强毒力岛大肠杆菌的毒力基因型和部分菌株毒力因子序列研究

为了解105株携带耶尔森菌强毒力岛(HPI)的大肠杆菌(E.coli)中相关毒力因子的流行情况和基因序列,根据GenBank中参考序列设计引物,采用PCR方法对广东地区养殖场来源的105分离株HPI+E.coli的fyuA、tsh、iucD、iss 4种毒力基因进行检测,统计基因类型；并对部分分离株的5种毒力基因(irp2和fuA、tsh、iucD、iss)进行了克隆与序列分析.结果显示105株HPI+E coli中4种毒力因子携带情况不尽一致,基因fyuA、tsh、iucD和iss的阳性率分别为55.24％、17.14％、49.52％和23.81％,105株HPI+E.coli共有13种基因型；分析表明,除iss基因与参考序列的同源性在88.0 ％～90.9％外,irp2、fyuA、tsh、iucD4种基因与GenBank中参考序列的同源性高达96％以上；广东省养殖场E.coli毒力因子基因型复杂,并以基因型irp2+ fyuA+ iucD+和仅含irp2+的菌株分离率最高,分别为17.14％和28％.

Virulence genotypes of 105 Escherichia coli with high pathogenicity island(HPI) and the HPI sequence analysis

To investigate the prevalence of high pathogenicity island(HPI) in Escherichia coli isolated in Guangdong area,the virulence genes of fyuA,tsh,iucD and iss genes in the 105 E.coli isolates were detected by PCR with the primers synthesized according to the E.coli reference strains,and some of the virulence genes were cloned and sequenced.The results showed that 13 genotypes and 4 genes of fyuA,tsh,iucD and iss were identified in the 105 isolates,of which displayed different positive percentages as 55.24%,17.14%,49.52% and 23.81% respectively.Except the homology of iss gene was from 88.0% to 90.9%,the homology of 4 genes(irp2,fyuA,tsh and iucD) is high above 96% with the reference sequences in GenBank.The genotypes of virulence factor in E.coli isolates from Guangdong were multiplicity.