耐万古霉素肠球菌耐药表型检测和基因型分析

摘要

Objective To research the resistant characteristics, genotype and prevalence of vancomycin-resistant Enterococci( VRE) . Methods K-B disc diffusion method was used to determine the susceptibility, minimum inhibi-tory concentration ( MIC) for vancomycin of VRE was detected by E-test method;VRE was then subjected to PCR for resistance related genes;6 strains sequencing results of PCR product were contrastively analyzed the amino acid sequence by BLAST. Results 6 VREFm strains were found from 193 strains enterococci;6 VREFm strains were completely resistant to high unit gentamicin, ampicillin, ciprofloxacin, teicoplanin,but were sensitive to linezolid and macrodantin,MIC for vancomycin was more than 256 mg/L;Genotypes were vanA;Amino acids in vanA gene have changed with Asn83→Asp( AAC→GAC) . Conclusion VRE in our hospital is mostly multi-drug resistant , which bringS difficulty in clinical treatment for its infection. So the hospital should strengthen the prevention and monitoring, to prevent the spread of VRE strains in the hospital and popular.%目的研究某院耐万古霉素肠球菌( VRE)的耐药特性、基因型及流行情况。方法采用K-B纸片扩散法进行药敏试验；使用E-test法检测VRE对万古霉素的最低抑菌浓度( MIC),PCR法检测万古霉素的耐药基因, BLAST法对6株PCR产物测序结果比对分析其氨基酸序列。结果193株肠球菌中检出6株万古霉素耐药屎肠球菌；该菌株对高单位庆大霉素、氨苄西林、环丙沙星、红霉素、利福平、替考拉宁均耐药,对呋喃妥因和利奈唑胺均敏感,对万古霉素的MIC值均>256 mg/L；基因型均为vanA；6株菌的vanA基因均有氨基酸发生了改变,其中5株菌均发生第83位氨基酸突变,由天冬酰胺( AAC)→天冬氨酸( GAC)。结论我院VRE多为多重耐药,给临床治疗VRE感染带来困难,医院应加强预防监测,阻止其在院内的传播和流行。