血流感染和皮肤软组织感染金黄色葡萄球菌耐药特征及多位点序列分型

Antimicrobial resistance and multilocus sequence typing of the Staphylococcus aureus isolates associated with bloodstream infection and skin and soft tissue infection

目的了解血流和皮肤软组织感染金黄色葡萄球菌(金葡菌)耐药特征及多位点序列分型(MLST)特征。方法采用BD Phoenix^(TM) 100进行金葡菌鉴定与药敏检测,采用WHONET 5.6软件及SPSS 19.0软件对细菌耐药率进行统计分析,采用MLST方法对金葡菌进行分子分型。结果共收集47株血流感染金葡菌和62株皮肤软组织感染金葡菌,血流和皮肤软组织感染金葡菌中MRSA检出率分别为21.3%(10株)和61.3%(38株),未发现对万古霉素、利奈唑胺、替考拉宁、夫西地酸和高水平莫匹罗星耐药菌株。血流感染MRSA株MLST分型以ST59为主(40.0%,4/10),MSSA株以ST7、ST188为主(各16.2%,6/37)。皮肤软组织感染MRSA株以ST338为主(47.4%,18/38),MSSA株以ST5、ST88为主(各12.5%,3/24)。结论血流感染MRSA检出率低于皮肤软组织感染(P<0.05),血流感染和皮肤软组织感染MRSA株优势ST分别为ST59和ST338,MSSA株ST呈多样化分布。

Objective To investigate the antimicrobial resistance and multilocus sequence typing(MLST)profiles of the Staphylococcus aureus isolates associated with bloodstream infection(BSI)and skin and soft tissue infection(SSTI).Methods The bacterial strains were identified and tested for susceptibility to antimicrobial agents on BD PhoenixTM 100 platform.The data of antimicrobial susceptibility were analyzed by WHONET 5.6 and SPSS 19.0 softwares.The S.aureus strains were typed by using MLST.Results Overall,47 nonduplicate S.aureus isolates associated with BSI and 62 nonduplicate S.aureus isolates associated with SSTI were collected.MRSA accounted for 21.3%and 61.3%in the S.aureus isolates associated with BSI and SSTI,respectively.No S.aureus isolate was found resistant to vancomycin,linezolid,teicoplanin,fusidic acid,or high-level mupirocin.MLST revealed that ST59 was the predominant ST of MRSA isolates in the S.aureus isolates associated with BSI(4/10,40.0%).ST7 and ST188 were the predominant STs of MSSA isolates(6/37,16.2%each).Among the S.aureus isolates associated with SSTI,ST338 was the predominant ST of MRSA isolates(18/38,47.4%).ST5 and ST88 were the predominant STs of MSSA isolates(3/24,12.5%each).Conclusions The prevalence of MRSA in the S.aureus associated with BSI was significantly lower than that in the strains associated with SSTI(P<0.05).The predominant ST of MRSA isolates associated with BSI and SSTI was ST59 and ST338,respectively.The ST types of MSSA isolates are more diverse.