万古霉素敏感性降低临床凝固酶阴性葡萄球菌的实验室检测

目的了解中日友好医院临床甲氧西林耐药凝同酶阴性葡萄球菌（MRCNS）糖肽类耐药的情况。方法聚合酶链反应（PCR）检测MRCNS；万古霉素耐药确证试验筛选对万古霉素敏感性下降的MRCNS株，E—test试验和最低抑菌浓度（MIC）法检测其MIC及多重PCR检测van基因；脉冲场凝胶电泳（PFGE）检测万古霉素敏感性下降MRCNS株的同源性。结果297株凝固酶阴性葡萄球菌（CNS）中mecA基因阳性率为89％；264株MRCNS中筛选出3株万古霉素敏感性下降溶血葡萄球菌；此3株溶血葡萄球菌未检出van基因；PFGE结果显示此3株溶血葡萄球菌没有同源性。结论万古霉素敏感性下降MRCNS的实验室检测和医院感染监测对预防和控制其传播非常重要。

Detection of the declined susceptibilities to vancomycin in clinical methicillin-resistant coagulase-negative Staphylococci and analysis of its molecular epidemiology

Objective To investigate the prevalence of vancomycin resistance in methicillin-resistant coagulasenegative Staphylococci（MRCNS） in China-Japan Friendship hospital. Methods MRCNS were detected with mecA-polymerase chain reaction（PCR）. Coagulase-negative Staphylococci（CNS） with reduced susceptibilities to vancomycin was detected with vancomycin agar screen test and the minimal inhibitory concentration（MIC） was determined with E-test and MIC method. Van gene was detected with mulitplex PCR. Pulsed field gel electrophoresis（PFGE） was used to analyse the similarities. Results 89% of mecA was detected in 297 CNS. 3 Staphylococci haemolyticus with declined susceptibilities to vanconaycin were sereened in 264 MRCNS but without van gene detected. PFGE showed these 3 Staphylococci haemolyticus were not from the same clone. Conclusions It is of great significance for clinical laboratory to detect the declined susceptibilities to vancomycin of MRCNS to prevent its infection and prevalence.