耐万古霉素肠球菌的基因型和同源性分析

Study of genotypes and homology of vancomycin-resistant enterococcus

目的了解中山大学附属第一医院临床分离的耐万古霉素肠球菌(VRE)的基因型和同源性,为本地区VRE的感染治疗和预防控制提依据。方法收集临床分离的VRE,E-Test法确定万古霉素、替考拉宁和利奈唑胺的最低抑菌浓度(MIC),多重PCR法检测万古霉素耐药基因,脉冲场凝胶电泳(PFGE)检测菌株的同源性。结果共收集到8株VRE菌株,均为屎肠球菌,分离自腹腔引流液。8株VRE均对万古霉素高度耐药(MIC≥256mg/L),对替考拉宁中介或耐药,对利奈唑胺、替加环素和四环素敏感,耐药基因型均为VanA;PFGE分型分为A、B两个克隆,其中7株为A克隆,1株为B克隆。结论中山大学附属第一医院VRE菌株均携带VanA基因,且多重耐药,在院内有小范围的流行,但非单一克隆流行。

Objective To understand the genotypes and homology of vancomycin-resistant enterococcus（VRE）isolated from the First Affiliated Hospital of Sun Yat-sen University to provide the laboratory basis for clinical treatment,prevention and control of VRE infection in this area.Methods The clinically isolated VRE strains were collected.Furthermore,the minimal inhibitory concentrations（MIC）of vancomycin,teicoplanin and linezolid were determined by the E-test;the vancomycin-resistant genes were identified by the multiple-PCR,and the homology of VRE strains by the pulsed field gel electrophoresis（PFGE）.Results All 8VRE strains,identified as enterococcus faecium,were isolated from abdominal drainage fluid,which were highly resistant to vancomycin（MIC≥256mg/L）,mediate or resistant to teicoplanin,and sensitive to linezolid,tigecycline and tetracycline.The vancomycin-resistant genotypes were determined to be VanA-type;which were divided into the clone A and B by the PFGE classification,in which 7strains were the clone A and 1strain was the clone B.Conclusion The 8VRE strains carry the Van gene and are multidrug-resistant,has a small range prevalence in our hospital,but is not the prevalence of single clone.