新生儿、医务人员及环境分离耐甲氧西林金黄色葡萄球菌的同源性

Homology of methicillinresistant Stphylococcus aureus isolated from neonates, health care workers, and environment

摘要:

目的了解某儿童医院新生儿重症监护病房（NICU）分离的耐甲氧西林金黄色葡萄球菌（MRSA）同源情况，探讨MRSA医院感染途径及防控策略。方法收集2014年10—12月NICU收治新生儿及环境标本中分离的MRSA菌株，采用VITEK 2全自动微生物分析系统和头孢西丁KB法确认MRSA，利用脉冲场凝胶电泳（PFGE）对MRSA分离株进行同源性分析。结果2014年10—12月NICU 检出MRSA 6株，其中3例新生儿（58床、70床、100床）送检标本均检出MRSA，58床护士（鼻拭子及手）和新生儿暖箱均检出MRSA。6株MRSA中 5株具有同源性，药敏结果显示，1～5号菌株对克林霉素和阿莫西林/克拉维酸均耐药，6号菌株的药敏谱与1～5号菌株稍有不同，6号对克林霉素和阿莫西林克拉维酸均敏感。PFGE结果显示，1～5号菌株为同一型别，6号菌株为不同型别。结论此次MRSA医院感染主要传播途径为接触传播，尤其是通过医务人员手导致交叉传播，利用PFGE技术早期分析鉴定流行菌株是预防医院感染暴发及流行病学研究的有效手段。

Abstract:

ObjectiveTo investigate the homology of methicillinresistant Stphylococcus aureus(MRSA) from the neonatal intensive care unit(NICU) of a children’s hospital, and evaluate routes and preventive strategies of MRSA healthcareassociated infection(HAI). MethodsMRSA strains from neonates and environment of NICU between October and December 2014 were collected, and strains were identified by VITEK2 microbial analysis system and cefoxitin KirbyBauer method, homology of MRSA was analyzed by pulsedfield gel electrophoresis (PFGE). ResultsA total of 6 MRSA strains were isolated from NICU between October and December 2014, 3 of which (bed58, 70, and 100) were detected MRSA from specimens, MRSA were isolated from neonatal incubator and nurse (nasal swabs and hands) who cared for neonate at bed 58. 5 of 6 MRSA strains were homology, antimicrobial susceptibility testing result showed that No. 1-5 strains were resistant to clindamycin and amoxicillin/clavulanic acid, No. 6 strain was slightly different from No. 1-5 strains, No. 6 strain was susceptible to both clindamycin and amoxicillin/clavulanic acid. PFGE results showed that No. 1-5 strains were of the same type, No. 6 strain was a different type. ConclusionThe main route of this MRSA transmission is contact transmission, especially through the hands of health care workers, identification and analysis of epidemic strains by PFGE technique is an effective measures to prevent HAI outbreak and perform epidemiological study