重症监护病房分离金黄色葡萄球菌的分子流行特征

目的了解某三甲医院重症监护病房(ICU)患者分离金黄色葡萄球菌的分子流行特点及其同源性,为有效控制医院感染的发生提供实验室依据。方法收集该院2013年3—8月ICU患者各类感染标本分离的62株金黄色葡萄球菌,采用PCR方法扩增7个管家基因并进行测序分析,采用多位点序列分型(MLST)技术获得菌株ST分型,对ST分型进行亲缘关系分析。结果 62株金黄色葡萄球菌均可以扩增出7个管家基因的特异性产物;共分为10个ST基因型,其中2个基因型为新发现的ST型(STn1和STn2),1个为国内新发现的ST型(ST675)。ST239是ICU患者分离的金黄色葡萄球菌主要ST型别,占74.20%,分布于6个ICU,分布范围最广;其次为ST5,分布于3个ICU。62株菌株在系统进化树上形成7个主要分支,检出耐甲氧西林金黄色葡萄球菌(MRSA)55株,占88.71%。结论医院ICU分离的金黄色葡萄球菌具有一定的同源性,并且少数型别表现出集中分布趋势。

Molecular epidemiological characteristics of Staphylococcus aureus isolated in intensive care units

ObjectiveTo investigate the molecular epidemiological characteristics and homology of Staphylococcus aureus (S. aureus) isolated from patients in intensive care units (ICUs) of a hospital, so as to provide laboratory basis for the effective control of healthcare associated infection(HAI). Methods62 S. aureus strains isolated from various specimens from ICU patients with infection in March August 2013 were collected, 7 housekeeping genes were amplified with polymerase chain reaction (PCR), the amplified products were sequenced, ST typing of strains was performed by multilocus sequence typing (MLST)， phylogenetic analysis of ST typing was conducted. Results62 S. aureus strains were amplified specific product of 7 housekeeping genes; there were 10 ST genotypes, in which 2 ST genotypes（STn1and STn2） were first discovered，1 ST genotype（ST675） was first discovered domestically. ST239 was the main ST type of S. aureus from ICU patients in this hospital, accounting for 74.20%，which distributed in 6 ICUs， ST5 distributed in 3 ICUs. 62 strains formed 7 main branches in the phylogenetic tree, 55 (88.71%) MRSA strains were detected. ConclusionS. aureus isolated from hospital ICUs has some homology, and the small number of types showed the trend of concentrated distribution.