万古霉素耐药肠球菌耐药基因检测及分子流行病学调查

Investigation on the drug-resistant genes and molecular epidemiology of vancomycin-resistant Enterococcus

目的：了解我院分离的万古霉素耐药肠球菌的耐药相关基因及流行情况。 方法：收集2012－2013年间分离的7株经E-test确认的万古霉素耐药肠球菌（VRE），提取基因组DNA，PCR检测van耐药基因型，多重PCR检测asal，gelE，cylA，esp，hyl 5个毒力基因；多位点序列分型（MLST）及脉冲场凝胶电泳（PFGE）进行流行病学调查。 结果：7株VRE耐药基因型van均为A型；有6株检测到毒力基因esp、hyl，其余为阴性；MLST及PFGE均显示菌株2、4、5、7为主要型别（ST 17），其余3株各不相同。 结论：我院分离的VRE耐药基因型为vanA型，毒力基因esp、hyl检出率较高，2013上半年有小规模VRE流行，应加强对于VRE的管控工作。

Objective：To investigate the drug resistant genes and molecular epidemiology of vancomycin-resistant Enterococcus （VRE） isolated from our hospital. Methods：Seven strains of VRE were isolated during 2012 to 2013, and validated by E-test. Then, their genomic DNA were extracted, and the Van type and the genes encoding virulence factors such as asal, gelE, cylA, esp and hyl were detected by PCR and multiplex PCR, respectively. The molecular epidemiology of VRE strains was investigated by multilocus sequence typing （MLST） and pulsed field gel electrophoresis （PFGE）. Results：All the seven VRE strains were vanA type and six of them were positive for esp and hyl genes. Both PFGE and MLST showed that stains 2, 4, 5 and 7 were proved to be the dominating type ST 17, and that the other three strains possesed different types. Conclusion：All VRE isolates in our hospital were vanA type and most had virulence genes esp and hyl. MLST and PFGE showed that there was a small scale of VRE prevalence in our hospital, indicating that more attention should be paid to monitor the VRE.