摘要目的 明确我国儿童皮肤软组织感染(skin and soft tissue infections,SSTIs)社区相关性耐甲氧西林金黄色葡萄球菌(community-associated Methicillin-resistant Staphylococcus aureus,CA-MRSA)的分子生物学特征.方法 收集我国13家儿童医院皮肤科门诊SSTIs来源的CA-MRSA,进行多位点基因分型(MLST)、葡萄球菌A蛋白序列(spa)分型及葡萄球菌盒式染色体(SCCmec)分型,同时进行杀白细胞毒素(Panton-Valentine Leukocidin,pvl)基因检测.结果 1 705株金黄色葡萄球菌来自SSTIs患儿,临床共分离CA-MRSA 44株,分离率仅为2.6％(44/1 705株).44株CA-MRSA共检测到2种SCCmec分型,为SCCmecⅣ和SCCmecⅤ型,分别占45.5％(20/44株)和54.5％(24/44株);13个MLST型别中,最主要的MLST型别是ST121(18/44株,40.9％),其次是ST59(9/44株,20.5％);15种spa型别中,最主要的spa型别是t437(18/44株,40.9％).ST121菌株有8种spa型别,以t2086最常见(6/18株,33.3％),而ST59仅有1种spa型别,即t437.华中与华东地区未见ST121、ST59和t437菌株型别.44株CA-MRSA中vl阳性率为9.1％(4/44株),均来自南部地区.结论 儿童SSTIs来源CA-MRSA最常见的克隆是MRSA-ST121-SCCmecⅣ/Ⅴ,CA-MRSA菌株分子流行病学已经发生变化,ST121已取代ST59成为目前主要流行株型别.

abstractsObjective To explore the molecular characteristics of community-associated Methicillin-resistant Staphylococcus aureus (CA-MRSA) from children with skin and soft tissue infection (SSTIs) in China.Methods CA-MRSA was collected from the outpatients in Department of Dermatology in 13 Children's Hospitals of China.Genotypic characteristics of CA-MRSA isolates were tested by adopting mnltilocus sequence typing (MLST),staphylococcal protein A (spa) typing and Staphyloccoccal cassette chromosome mec (SCCmec) typing.And the presence of Panton-Valentine leukocidin genes(pvl) was determined also.Results Overall,1 705 strains of Staphylococcus aureus were isolated from SSTIs children,and CA-MRSA accounted for 2.6％ (44/1 705 strains).Two types of SCCmec were detected in all the CA-MRSA strains,and the main types were SCCmec Ⅳ and SCCmec Ⅴ,accounting for 45.5 ％ (20/44 strains) and 54.5 ％ (24/44 strains),respectively.Thirteen MLST types (STs) and 15 spa types were detected among CA-MRSA.The most prevalent MLST was ST121 (18/44 strains,40.9％),followed by ST59 (9/44 strains,20.5％).Additionally,t437 was predominant,accounting for 40.9％ (18/44 strains).ST121 strain had 8 spa types,and t2086 was the most common type (6/18 strains,33.3％);while ST59 had only 1 spa type,t437.No ST121,ST59 and t437 strains were found in Central and Eastern region of China.Only 4 (9.1％) of the 44 CA-MRSA strains harbored pvl genes which were all from Southern region.Conclusions The most common clone of SSTIs CA-MRSA in children is MRSA-ST121-SCCmec Ⅳ/Ⅴ,as the molecular epidemiology of CA-MRSA strain has changed,ST121 has replaced ST59 to become the main epidemic strains.