耐万古霉素肠球菌与定植肠球菌的致病基因检测

Detection of virulence genes in clinically isolated Vancomycin-resistant and Vancomycin-sensitive Enterococci

目的通过对耐万古霉素肠球菌(Vancomycin-resistant Enterococci,VRE)及分离非耐万古霉素肠球菌(Vancomycin-sensitive Enterococci,VSE)致病基因的筛查,了解致病基因分布情况,探索肠球菌致病机制,为日后致病机制的研究提供基线资料。方法收集浙江省人民医院的部分临床患者标本中分离出的VRE,与ICU采集的患者肛周和手臂标本分离的肠球菌属细菌。以PCR方法筛查出ace、asa1、cylA、efaA、esp、gelE和hyl七种致病基因。结果 VRE组esp总体阳性率最高,约占71.4%,其中屎肠球菌中esp最高,约占73.5%,其致病基因携带谱以"esp-hyl"基因组合为主;粪肠球菌全部菌株均携带efaA基因,其致病基因均为三种以上基因组合,以"esp-cyl A-gelE-asa1-efaA"多见。VSE组总体阳性率同样esp最高,约占40.0%;其中屎肠球菌以esp、hyl单个基因携带为主;粪肠球菌以"esp-ace-cylA-gelE-asa1-efaA"最多见。结论两种肠球菌各种致病基因携带率差异较大,两种肠球菌致病机制存在差异,本地区致病基因发挥作用的以esp、hyl为主。

Objective To explore the pathogenic mechanism of Enterococci spp.by screening the virulence genes of Vancomycin-resistant Enterococci(VRE)and Vancomycin-sensitive Enterococci(VSE),and provide baseline information for the study on the pathogenesis.Methods VRE strains was collected from June2011 to January 2014 in The People′s Hospital of Zhejiang and from the perianal and arm swabs of patients in ICU.The distributions of virulence genes ace,asa1,cylA,efaA,esp,gelE and hyl were detected by using PCR method.Results The detection rate of esp was the highest in both VRE Enterococcus faecium(73.5%)and VSE Enterococcus faecium(42.6%),and the virulence genes carried by VRE strains were mainly in'esp-hyl'form.All the Enterococcusfaecalisstrains carried efaA,the virulence genes of which contained three or more gene with'esp-cylA-gelE-asa1-efaA'being predominant.In the VSE strains,the overall detection rate of esp was also the high test at about 40.0%;most Enterococcus faeciumstrains carried either esp or hyl,while Enterococcus faecalis strains carried 'esp-ace-cylA-gelE-asa1-efaA'.Conclusion The detection rates of various pathogenic genes were significantly different between the two Enterococci,and the pathogenic mechanisms were different.The genes espand hyl play a main role in the pathogenesis in the region.