福建东南沿海某战区医院MRSA感染特点及基因多态性分型研究

A Study on Characteristics and Genetic Polymorphisms of MRSA Infection in a PLA Hospital in Southeast Coastal Region of Fujian Province

目的了解福建东南沿海某战区医院MRSA感染特点及基因多态性分型情况,为制定院内MRSA感染的防治策略提供分子生物学依据。方法采用头孢西丁试纸片法初步鉴定MRSA菌株,聚合酶链反应(PCR)技术检测Mec A基因,最终鉴定临床送检标本所检测出的MRSA菌株,并通过随机引物DNA扩增技术(RAPD)对所检测的MRSA菌株进行基因分型研究。结果经PCR对Mec A基因检测,从临床标本及医护人员身上共分离出42株MRSA菌株。采用随机引物DNA扩增技术(RAPD)对细菌进行基因分型,根据同源性分析,42株临床菌株共可以分为12型。其中Ⅰ型共7株,Ⅱ型共2株,Ⅲ型共4株,Ⅳ型共4株,Ⅴ型共7株,Ⅵ、Ⅶ及Ⅷ各1株,Ⅸ型共8株,Ⅹ型共2株,Ⅺ型共3株,Ⅻ型共2株。结论本院MRSA菌株存在相似度大小不同的遗传距离,医院内存在交叉感染可能。

Objective To study the characteristics and genetic polymorphisms of methicillin resistant staphylococcus aureus（ MRSA） infection in a PLA hospital in southeast coastal region of Fujian Province,and to provide the molecular biological basis for prevention and control strategies of nosocomial MRSA infection. Methods MRSA strains were initially detected using Cefoxitin indicator paper,and Mec A genes were detected using polymerase chain reaction（ PCR）technology,MRSA strains detected from clinical samples were identified,and then genotyping of detected MRSA strains were studied using synthetic primer and random amplification of polymorphic DNA technique（ RAPD）. Results The Mec A genes after PCR detection showed that 42 strains of MRSA strains were isolated from clinical specimens and the medical staff. The MRSA genotypes were differentiated with RAPD technology,and homologous analysis categorized 42 clinical MRSA strains into 12 genotypes,in which 7 strains of Type I,2 of Type II,4 of Type III,4 of Type IV,7 of Type V,1 of Type VI,1 of Type VII,1 of Type VIII,8 of Type IX,2 of Type X,3 of Type XI and 2 of Type XII. Conclusion MRSA strains have genetic distances of different sizes of similarity in our hospital,therefore nosocomial cross infection is possible.