【摘要】 目的多中心研究我国2005年苯唑西林耐药的金黄色葡萄球菌(MRSA)分子流行病学特征。方法收集2005年1—12月14个城市17家教学医院连续分离的非重复 MRSA 395株,通过多重 PCR 对 MRSA 进行葡萄球菌染色体 mec(SCCmec)分型,脉冲场凝胶电泳(PFGE)进行同源性分析。根据药敏结果、PFGE、SCCmec 型别和分布地区选出53株进行多位点序列分型(MLST)。采用PCR 检测毒素基因。结果 395株 MRSA 中,SCCmecⅢ型243株、占61.5%,不能分型菌株96株、占24.3%,Ⅱ型56株、占14.2%;沈阳 SCCmecⅡ型占60.7%(17/28),远高于其他地区(0～42.9%)。PFGE 共有24种分型,42种亚型,其中 A 型占50.1%,为12个城市13家医院所共有,R 型占23.5%,存在于8个城市9家医院。MLST 共有6种分型,其中序列分型(ST)239占75.5%,ST5占17.0%。395株 MRSA 中,pvl 基因检出率为2.5%。结论我国 MRSA 主要获得Ⅱ型、Ⅲ型 SCCmec 基因,SCCmec 的分布有地区差异。一些地区发生 MRSA 的暴发,并且地区问发生流行克隆的传播。有些流行克隆可能来源于某些世界流行克隆株的传播。更多还原

【Abstract】 Objective To investigate the molecular epidemiology of methicillin-resistant Staphylococcus aureus in China in 2005.Methods From January to December 2005,395 consecutive and non-repetitive isolates of methicillin-resistant Staphylococcus aureus were collected from 17 teaching hospitals in 14 cities.The genotypes of SCCmec were determined by multiplex PCR pulsed-field gel electrophoresis (PFGE)was used to type the chromosome DNA of MRSA.Muhilocus sequence typing(MLST)was used to type the housekeeping genes.Fifty-three strains were selected for MLST typing according to the antimicrobials susceptibility patterns,PFGE types,SCCmec types and the distribution of the regions.The toxin gene was detected by PCR.Results Among 395 isolates of MRSA,SCCmec Ⅲ,untypeable type and type Ⅱ accounted for 61.5%(243/395),24.3%(96/395)and 14.2%(56/395)respectively.In Shenyang,60.7%(17/28)of the isolates were SCCmec Ⅱ,which was significantly higher than other areas. Twenty-four different types and 42 subtypes were found by PFGE typing.Clone A accounted for 50.1%, existing in 13 teaching hospitals in 12 cities and clone R accounted for 23.5%,existing in 9 teaching hospitals in 8 cities.Six sequence types(ST)were found in these isolates with ST239 and ST5 accounting for 75.5% and 17.0% among these isolates,respectively.The prevalence of pvl gene was 2.5% among 395 isolates of MRSA.Conclusions The most types of SCCmec in China were Ⅲ and Ⅱ,and distribution of SCCmec types differed among regions.MRSA outbreaks caused by epidemic multiple-drug resistant clones occurred in big teaching hospitals in China.Meanwhile,the same PFGE pattern may spread among areas. Several international epidemic MRSA clones may exist in China.更多还原