儿童标本中分离MRSA的SCCmec基因分型及耐药性分析

目的 了解亳州地区儿童耐甲氧西林金黄色葡萄球菌(methicillin resistant staphylococcus aureus,MRSA)的SCCmec基因分型及其耐药性。 方法 收集2018年12月—2019年3月亳州市人民医院儿科共6个病区临床分离的89株MRSA菌株,采用PCR方法对其进行SCCmec基因分型;VITEK 2 compact全自动微生物分析仪进行抗菌药物敏感性试验,并采用WHONET 5.6软件统计药敏结果并进行分析。 结果 89株MRSA以SCCmecⅣa型为主,占55.1%(49/89),其次SCCmecⅢ型12.4%(11/89),SCCmecⅡ型1.1%(1/89),未分型31.4%(28/89),未见SCCmecⅠ型和Ⅴ型;89株MRSA对青霉素均耐药,对红霉素、克林霉素均高耐药,耐药率分别为87.6%、62.9%,对喹诺酮类、庆大霉素、甲氧苄啶/磺胺甲恶唑的耐药率均低于10%;而49株SCCmecⅣa型对红霉素、克林霉素的耐药率略升高,分别为91.8%、77.6%,对喹诺酮类药物耐药率4.1%,有所下降,而对甲氧苄啶/磺胺甲恶唑、庆大霉素均敏感;以上菌株未发现对万古霉素、利奈唑胺、奎奴普丁/达福普汀及替加环素耐药。 结论 目前亳州地区儿童分离的MRSA主要以SCCmecⅣa型为主要流行株,对多种抗菌药物呈不同程度耐药。 

SCCmec genotypes and drug resistance analysis of isolated MRSA in children

Objective To investigate the SCCmec genotypes and drug resistance of methicillin-resistant staphylococcus aureus(MRSA) isolated from children in Bozhou, Anhui province. Methods From December 2018 to March 2019, 89 MRSA strains isolated from 6 pediatrics wards in the People's Hospital of Bozhou were collected. The SCCmec genotypes of MRSA strains were detected by PCR. Antimicrobial susceptibility test was performed by VITEK 2 compact. Statistical analysis was performed using WHONET 5.6 software. Results Among 89 MRSA strains, SCCmec Ⅳa was the main type, accounting for 55.1%(49/89) of the total strains, followed by SCCmec type Ⅲ 12.4%(11/89), SCCmec type 1.1%(1/89), respectively. Untyped 31.4%(28/89)and SCCmecⅠ and Ⅴ type were not detected. All MRSA strains were resistant to penicillin and the resistance rates to erythromycin and clindamycin were higher, which was 87.6% and 62.9% respectively. The resistance rates to quinolones, gentamicin and trimethoprim/sulfamethoxazole were less than 10%. The resistance rates of the 49 strains of SCCmec type Ⅳa to erythromycin and clindamycin were slightly increased, which was 91.8% and 77.6%, respectively, while the resistance rate to quinolones was 4.1%, and all of the 49 strains were susceptible to gentamicin and trimethoprim/sulfamethoxazole. None of the MRSA strains were found to be resistant to vancomycin, linezolid, quinupristin/dalfopristin and tigecycline. Conclusion The prevalence of MRSA isolated from children in Bozhou was mainly SCCmec Ⅳa type strains, and they showed various degrees of resistance to different antimicrobial agents.