耐甲氧西林金黃色葡萄球菌耐药性及基因分型分析

Drug resistance and gene typing of methicillin-resistant staphylococcus aureus

目的了解耐甲氧西林金黄色葡萄球菌(MRSA)的耐药性及基因多态性分型情况,为医院感染控制提供流行病学依据。方法参照2009年CLSI标准,对中山大学附属第二医院2003年1月-2009年6月各种临床标本中分离的188株MRSA,用K-B法对10种抗菌药物进行的敏感性检测;微量稀释法对万古霉素、利奈唑胺的敏感性进行检测;利用随机引物PCR(AP-PCR)对MRSA基因多态性进行分型,应用Bionumer图像分析软件分析其同源性。结果 188株MRSA对利奈唑胺、替考拉宁、万古霉素敏感率均为100.0%,对氯霉素、利福平的敏感率为71.8%及70.7%,其他被检测的抗菌药物的敏感率均<50.0%;AP-PCR方法将188株MRSA分为20个基因型(A～Q和3个独立型),主要分为A型(43株)、B型(33株)和C型(18株)。结论 MRSA对利奈唑胺、替考拉宁、万古霉素敏感性高,而对临床常用的其他抗菌药物呈多药耐药性;基因分型以A、B、C型为主。

OBJECTIVE To study the drug resistance and the gene polymorphism typing of methicillin-resistant Staphylococcus aureus（MRSA）,to provide the epidemiology basis for the infection control.METHODS Totally 188 strains were isolated from the second affiliated hospital of Sun Yat-sen university from 2003 to 2009.The antibiotic susceptibility test was performed by K-B disk diffusion method and micro-dilution.Their genes were typed by the AP-PCR.The Bionumer image analysis software was applied to analyze their homology.RESULTS The sensitive rates to oxazolidine,teicoplanin and vancomycin were 100.0%,while the sensitivity rates to chloramphenicol,rifampicin were 71.8% and 70.7% respectively,and to other antibiotics were less than 50.0%.MRSA genotyping can be divided into 20 genotypes（type A～Q and 3 stains were typed as an independent type）,mainly including type A（43 stains）,type B（33 stains）,and type C（18 stains）.CONCLUSIONS MRSA isolates show a higher sensitivity to linezolid,teicoplanin,vancomycin and are multi-drug resistant to commonly used antibiotics in clinics;Type A,B and C become the main genotypes of MRSA.