2株利奈唑胺中介粪肠球菌23S rRNA V区基因变异检测

摘要

目的：研究粪肠球菌对利奈唑胺(LNZ)的耐药情况和耐药机制,为临床合理用药提供依据。方法收集2012年1月-2013年1月深圳市南山区人民医院接受 LNZ治疗患者痰液标本分离的粪肠球菌12株,采用琼脂稀释法测定抗菌药物的最低抑菌浓度(MIC),聚合酶链反应(PCR)扩增23S rRNA V 区基因,并进行测序分析。结果12株菌中,2株为中介株(菌株编号分别为3和6),10株为敏感株。2株中介株均检测到 G2576U 突变,其中1株(编号6)还同时存在 C2424U 突变；10株敏感株未检测到变异。C2424U 和 G2576U 突变分别发生在23S rRNA V区基因的 R1区和 R4区。结论粪肠球菌 LNZ中介株中发现23S rRNA V区基因变异,提示临床应密切关注 LNZ的 MIC变化。%Objective To evaluate antimicrobial resistance and antimicrobial resistance mechanisms of Enterococcus faecalis (E.faecalis)to linezolid (LNZ),and provide basis for clinical rational drug use.Methods Twelve E.faecalis strains isolated from sputum of patients who received LNZ therapy in a hospital between January 2012 and January 2013 were collected.The minimum inhibitory concentrations (MICs)of antimicrobial agents were de-termined by agar dilution method,23S rRNA V region gene of E.faecalis was amplified by polymerase chain reac-tion,the amplified products were sequenced.Results Of 1 2 isolates,2 were intermediate strains and 1 0 sensitive strains.The G2576U mutation was detected in 2 intermediate strains,1 of which was also detected G2424U muta-tion;the variations were not detected in 10 sensitive strains.C2424U and G2576U mutation existed in R1 and R4 region respectively.Conclusion 23S rRNA V region gene mutations are found in the intermediate strains of E.faecalis.Change in MIC values of linezolid should be paid close attention in clinical use.