金黄色葡萄球菌SPA分型及毒力基因检测

Staphylococcus Aureus SPA Typing and Virulence Gene Detection

目的:研究临床分离金黄色葡萄球菌(SA)的蛋白A基因多态性及其所携带的毒力基因,为控制SA的感染和传播提供基础理论依据。方法:选取2018年10月—2019年3月北京航天总医院检验科微生物室分离得到的临床来源非重复金黄色葡萄球菌50株,其中来源于痰液35株、血液6株、脓液3株。其他来源6株(包括尿液、胸水、腹水等)。检测菌株携带mecA基因和杀白细胞毒素(PVL)基因等7种毒力基因的情况,并对菌株进行SPA基因分型分析。结果:50株SA菌株中,共检出耐甲氧西林金黄色葡萄球菌(MRSA)28株(56.0%),其中mecA基因阳性28株(100%);甲氧西林敏感金黄色葡萄球菌(MSSA)22株(44.0%),mecA基因均为阴性。MRSA分为4个SPA型别,以t030(82.1%)为主,MSSA共分为12个葡萄球菌蛋白A(SPA)型别,以t1451、t091和t078位列前3位,分别占22.7%、18.2%和13.6%,检出2株PVL阳性菌株。结论:t030是MRSA临床分离株中的SPA优势型别,在本医院内广泛传播。MSSA遗传多样性高,以t1451、t091和t078位列前3位。

Objective:To study the protein A gene polymorphism of clinical isolates of Staphylococcus aureus(SA)and the virulence genes they carry to provide a basic theoretical basis for controlling the infection and transmission of SA.Methods:50 strains of non-repetitive S.aureus from clinical sources,including 35 strains from sputum,6 strains from blood,3 strains from pus,and 6 strains from other sources(including urine,pleural fluid,ascites,etc.),were selected and obtained from the microbiology de⁃partment of the hospital from October 2018 to March 2019.The strains were tested for carrying seven virulence genes,including the mecA gene and the panton-valentine leukocidin(pvl)gene,and SPA genotyping analysis was performed on the strains.Re⁃sults:A total of 28(56.0%)methicillin-resistant S.aureus(MRSA)strains were detected among the 50 SA strains,of which 28(100%)were positive for the mecA gene.A total of 22 strains(44.0%)of methicillin-sensitive S.aureus(MSSA)were detected,and all of them were negative for mecA gene.MRSA was divided into 4 spa types,with t030(82.1%)dominating.mSSA was divided in⁃to 12 staphylococcus protein A(SPA)types,with t1451,t091 and t078 being the top 3,accounting for 22.7%,18.2%and 13.6%,respectively.Two pvl-positive strains were detected.Conclusion:The t030 is the spa dominant strain of MRSA clinical isolates and is widely spread in our hospital.t1451,t091 and t078 are the top 3 of the high genetic diversity of MSSA.