血流感染MRSA中的ST239克隆株快速检测与分析

摘要

目的 评价多重PCR法对耐甲氧西林金黄色葡萄球菌(MRSA) ST239克隆株的快速检测及合肥地区血流感染MRSA的分子流行现状.方法 收集2008年至2013年安徽医科大学第一附属医院及第二附属医院临床分离的血流感染金黄色葡萄球菌的106株MRSA进行相关耐药性分析,并采用多重PCR技术对ST239型克隆株进行快速检测,同时运用多位点序列分型(MLST)加以确认及葡萄球菌染色体mec基因盒(SCCmec)分型分析.结果 106株血流感染金黄色葡萄球菌中MRSA有51株,占48.1％,MRSA均为多耐药菌,对红霉素、氨基糖苷类和喹诺酮类耐药率明显高于甲氧西林敏感金黄色葡萄球菌(MSSA),MRSA和MSSA对磺胺甲噁唑/甲氧苄啶的敏感率分别为86.3％和 94.5％;51株MRSA中有47株为ST239快速检测阳性,阳性率高达92.2％;随机选取20株ST239初筛阳性的MRSA经MLST验证和SCCmec分型后确认为MRSA-ST239-SCCmecⅢ型.结论 合肥地区血流感染MRSA近半数为多重耐药克隆MRSA-ST239-SCCmecⅢ型,运用多重PCR技术能够快速检测ST239克隆株.%Objective To evaluation the method of rapid detection of Methicillin-resistant Stphylococcus aureus (MRSA) ST239 clones with multiplex PCR assay and investigation of the epidemic status of MRSA blood stream infections in Hefei area.Methods Antibiotic susceptibility testing were applied to MRSA isolates from bloodstream infection,rapid screening and confirmation of MRSA ST239 clones by using multiplex PCR,Multilocus Sequence typing (MLST) and Staphyloccoccal Cassette Chromosome mec(SCCmec) typing.Results 51 of 106 clinic isolates Staphylococcus aureus were identified as MRSA,accounting for 48.1％.The resistance rate of MRSA to erythromycin,aminoglycosides and quinolone were significantly higher than Methicillin Sensitive Staphylococcus aureus (MSSA).Both MRSA and MSSA had a high sensitivity to cotrimoxazole,the sensivity rates were 86.3％ and 94.5％,respectively; 47 of 51 isolates of MRSA that detected by MRSA ST239 rapid screening were ST239 clones.Randomly selected 20 positive screening stains were confirmed as MRSA-ST239-SCCmec Ⅲ by MLST and SCCmectyping.Conclusions In Hefei area,nearly half of MRSA bloodstream infections in clinical isolates are MRSA-ST239-SCCmeclⅢ type and serious multidrug-resistance.The rapid detection of ST239 clones by multiplex PCR is a reliable and effective method for large-scale screening in laboratory.