Alfizah H, Norazah A, Nordiah A J, Lim V K E
Department of Medical Microbiology & Immunology, Faculty of Medicine, National University of Malaysia (UKM), Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur.
Med J Malaysia. 2002 Sep;57(3):319-28.
Methicillin-resistant Staphylococcus aureus (MRSA) has been prevalent in our hospital over the last three years. Differentiation among MRSA strains by DNA typing in addition to antibiotic resistance pattern surveillance is crucial in order to implement infection control measures. The aim of this study was to characterize MRSA isolates from patients admitted to Hospital Universiti Kebangsaan Malaysia (HUKM) by phenotypic (analyses of antibiotic susceptibility pattern) and genotypic (PFGE) techniques to determine the genetic relatedness of the MRSA involved and to identify endemic clonal profiles of MRSA circulating in HUKM. Seventy one MRSA strains collected between January to March 2000 from patients from various wards in HUKM were tested for antimicrobial resistance and typed by pulsed-field gel electrophoresis (PFGE). Four major types of PFGE patterns were identified (A, B, C and D) among MRSA strains. Two predominant PFGE types were recognised, Type A (59.2%) and Type B (33.8%). Most of these strains were isolated from ICU, Surgical wards and Medical wards. MRSA strains with different PFGE patterns appeared to be widespread among wards. Strains with the same antibiotype could be of different PFGE types. Most of isolates were resistant to ciprofloxacin, erythromycin, gentamicin and penicillin. One isolate with a unique PFGE pattern Type D and susceptible to gentamicin was identified as a different clone. Some isolates obtained from the same patient showed different PFGE subtypes suggesting that these patients were infected/colonized with multiple MRSA strains. PFGE analysis suggests that MRSA strains with different PFGE types was propagated within our hospital. The relationship between antibiotic susceptibility and PFGE patterns was independent. The ability of PFGE technique in differentiating our MRSA strains make it a method of choice for investigating the source, transmission and spread of nosocomial MRSA infection, and thus an appropriate control programme can be implemented to prevent the spread of MRSA infection.
在过去三年中，耐甲氧西林金黄色葡萄球菌（MRSA）在我们医院一直很普遍。除了监测抗生素耐药模式外，通过DNA分型对MRSA菌株进行区分对于实施感染控制措施至关重要。本研究的目的是通过表型（抗生素敏感性模式分析）和基因型（PFGE）技术对马来西亚国民大学医院（HUKM）收治患者的MRSA分离株进行特征分析，以确定所涉及的MRSA的遗传相关性，并识别在HUKM中传播的MRSA的地方性克隆谱。对2000年1月至3月从HUKM各个病房的患者中收集的71株MRSA菌株进行了抗菌药物耐药性测试，并通过脉冲场凝胶电泳（PFGE）进行分型。在MRSA菌株中鉴定出四种主要的PFGE模式（A、B、C和D）。识别出两种主要的PFGE类型，A型（59.2%）和B型（33.8%）。这些菌株大多分离自重症监护病房、外科病房和内科病房。具有不同PFGE模式的MRSA菌株似乎在各病房中广泛存在。具有相同抗菌型的菌株可能属于不同的PFGE类型。大多数分离株对环丙沙星、红霉素、庆大霉素和青霉素耐药。一株具有独特PFGE模式D且对庆大霉素敏感的分离株被鉴定为不同的克隆。从同一患者获得的一些分离株显示出不同的PFGE亚型，表明这些患者感染/定植了多种MRSA菌株。PFGE分析表明，具有不同PFGE类型的MRSA菌株在我们医院内传播。抗生素敏感性与PFGE模式之间的关系是独立的。PFGE技术区分我们的MRSA菌株的能力使其成为调查医院内MRSA感染的来源、传播和扩散的首选方法，因此可以实施适当的控制方案以防止MRSA感染的传播。
