21株耐甲氧西林金黄色葡萄球菌的SCCmec基因分型及耐药性分析

SCCmecgenotyping of 21 strains of methicillin-resistant Staphylococcus aureusand drug resistance

目的将医院分离到的21株耐甲氧西林金黄色葡萄球菌(MRSA)进行SCCmec基因分型,并进行耐药性研究,为临床诊断及治疗提供理论依据。方法应用聚合酶链反应(PCR)对21株MRSA进行基因分型;采用K-B纸片扩散法进行抗菌药物敏感试验。结果 21株MRSA中SCCmecⅠ型1株占4.8%,Ⅱ型2株占9.5%,Ⅲ型6株占28.6%,Ⅳ型12株占57.1%;21株MRSA对万古霉素耐药率为0,对青霉素、苯唑西林的耐药率均为100.0%,对头孢唑林、红霉素、四环素、克林霉素的耐药率分别为47.6%、42.9%、38.1%、33.3%,对庆大霉素、氯霉素、环丙沙星的耐药率分别为28.6%、23.8%、19.0%。结论医院MRSA的基因类型以SCCmecⅣ型为主;未发现对万古霉素耐药的菌株,分离到的MRSA中,不同型别的耐药率与基因型之间存在有一定的关系,且这些菌株均为多药耐药株。

OBJECTIVE To investigate the SCCmec genotyping of 21 strains of methicillin-resistant Staphylococcus aureus（MRSA） and study the drug resistance so as to provide the theoretical basis for clinical diagnosis and treatment. METHODS The genotyping of 21 strains of MRSA was performed with PCR; the drug susceptibility testing was carried out by K-B disk diffusion. RESULTS Of 21 strains of MRSA, there was 1 （4.8%） strain of SCCmecI type, 2 （9.5%） strains of SCCmec Ⅱ type , 6 （28.6%） strains of SCCmec Ⅲ type, and 12 （57.1%） strains of SCCmec Ⅳ type; the drug resistance rates of the 21 strains of MRSA to both penicillin and oxacillin were 0, the drug resistance rates to cephazolin, erythromycin, tetracycline, clindamycin, gentamicin, chloramphenicol, and ciprofloxacin were 47. 6% ,42. 9%, 38. 1%, 33. 3%,28. 6%, 23, 8%, and 19. 0%, respectively. CONCLUSION SCCrnec Ⅳ is the predominant genotype of MRSA , there are no vancomycin-resistant strains detected, and the drug resistance rate of the isolated MRSA is correlated with the genotype in certain extent, and all the strains are multidrug-resistant.