耐甲氧西林金黄色葡萄球菌医院感染爆发流行的实验室调查

Laboratory investigation on the nosocomial infection outbreak of methicillin-resistant Staphylococcus aureus

目的采用耐甲氧西林金黄色葡萄球菌(MRSA)mecA基因相关高变区(HVR)长度多态性分型了解MRSA的医院感染爆发流行情况。方法选取临床分离的38株MRSA菌株,采用聚合酶链反应(PCR)方法扩增MRSA mecA基因HVR,据扩增片段大小差异进行基因分型。结果根据PCR产物片段大小,38株MRSA被分为A、B、C、D 4个基因型,其中C型23株(60.53%)、A型7株(18.42%)、B型3株(7.89%)、D型2株(5.26%)、未分型3株(7.89%)。C型在临床各科室均有分布,但主要集中于老干部科。MRSA呈严重且多重耐药,故首选抗菌药物为万古霉素、替加环素、奎奴普汀/达福普汀和替考拉宁。结论医院内存在着MRSA菌株的克隆传播,应加强检测,控制医院感染爆发流行。

Objective Through detecting methicillin-resistant Staphylococcus aureus（ MRSA） with mecA gene related hyper-variable region（ HVR） genotyping to understand the nosocomial infection outbreak of MRSA. Methods By polymerase chain reaction（ PCR）,the HVR of MRSA mecA gene from 38 isolates of MRSA was amplified.According to size differences,the amplified fragments were genotyped. Results According to the PCR fragment size,38 isolates of MRSA were classified into A,B,C and D genotypes respectively,in which C genotype was the most common type（ 23 isolates,60. 53%）,followed by A genotype（ 7 isolates,18. 42%）,B genotype（ 3 isolates,7. 89%）,D genotype（ 2 isolates,5. 26%） and no genotype（ 3 isolates,7. 89%）. C genotype distributed in various departments,mainly in cadre department. MRSA showed serious multi-drug resistance. Therefore,the first choice of antibiotic therapy was vancomycin,teicoplanin /dalfopristin and tigecycline. Conclusions There was a spread of nosocomial MRSA cloning in hospital,and it should be paid attention to strengthen the detection and control of nosocomial infection outbreak.