新生儿金黄色葡萄球菌皮肤和软组织化脓性感染临床分离株分子及毒力特征

目的 监测新生儿金黄色葡萄球菌（SA）皮肤和软组织化脓性感染（SSTIs）临床分离株的分子和毒力特征，为预防和治疗新生儿SSTIs提供理论依据。方法 收集2015年5月至2016年4月首都医科大学附属北京儿童医院NICU临床诊断为SSTIs的病例，对SA分离株进行agr、MLST、spa 和SCCmec 分型；通过PCR对SA菌株进行21种超抗原毒素基因、sasX、PVL基因检测。结果 44例SSTIs新生儿，男22例，中位年龄4.5（0～22）d，均为社区获得性感染。共分离出13例SA菌株，其中MRSA 7株，MRSA最常见的克隆是agrⅠ-MRSA-ST59-SCCmecⅣa，13株SA包含2～8种超抗原基因型，最常见的毒素基因型为sek-seb-seq，有6株SA PVL基因阳性，均不携带sasX基因。结论 新生儿SSTIs中，SA携带率较低， agrⅠ-MRSA-ST59-SCCmecⅣa-t437是MRSA最主要的流行克隆，SA分离株超抗原基因携带率高。

Molecular and virulence characterization of methicilin-resistant Staphylococcus aureus strains isolated from neonates with skin and soft tissue infection

Objective To investigate the molecular and virulence characterization of Staphylococcus aureus (SA) isolated from neonates with skin and soft tissue infections(SSTIs) through one-year prospective surveillance study,and to provide the scientific evidence for prevention and control of SA infection.Methods Cases of SSTIs in neonates were prospectively collected from May 2015 to April 2016 in NICU of Beijing Children's Hospital,the clinical data were recorded,the multilocus sequence typing(MLST) and Staphylococcal cassette chromosome mec (SCCmec) types were analyzed by multiplex polymerase chain reaction method,the spa type was analyzed by PCR.PCR was also used to test 23 virulence genes,including 21 superantigen genes,PVL gene and sasX gene.Results A total of 13 SA strains were collected,including 7 MRSA,the most common clone of MRSA was agr Ⅰ-ST59-SCCmec Ⅳ-t437.It was found that all strains contained at least two superantigen toxin genes,and 6 strains were PVL positive.SasX was not detected in any of the isolates.Conclusion The carrying rate of SA from SSTIs in neonates was low,the most common clone of MRSA was agr Ⅰ-ST59-SCCmecⅣ-t437,the carrying rate of superantigen was high.