烧伤病房MRSA医院感染暴发的PFGE分型研究

利用表型分型和基因分型的方法解析医院感染常见致病菌——耐甲氧西林金黄色葡萄球菌(MRSA)造成医院感染暴发的可能传播途径。本实验对某医院烧伤科、ICU、肿瘤科病房内从患者和环境分离的19株MRSA,进行了16种抗生素的耐药性实验和全基因组稀有位点限制性内切酶酶切脉冲凝胶电泳(PFGE)分析,并聚类分析归纳了菌株之间的相关性。结果发现在19株MRSA中有11株属于同一个菌种A型,在这些菌株中,有8株属于相同的克隆亚型A1型,分别来自烧伤科和ICU患者以及烧伤科医生、护士的手。4株属于B型,均分离自同一烧伤病房。这暗示该医院可能存在MRSA(A型)院内感染的暴发,并且存在B型流行的潜在危险。MRSA很有可能通过医护工作人员的手及鼻腔等媒介在患者间传播。因此,加强医护人员的感染控制观念,利用灵敏、可靠且分辨率强的分型技术加强MRSA感染监控至关重要。

PFGE Genotyping of MRSA Outbreak in a Burn Unit

To explore the epidemiological character of Methicillin-resistant Stapkylococcus aureus (MRSA) by the phenotyping and genotyping motheds and to investgate the source, transmission, and the spread of nosocomial MRSA infection, consequently, reducing the nosocomial infection of MRSA. In this study, 19 MRSA strains were isolated from patients and environment in a hospital in two months. Patterns of resistantce against 16 antimicrobial agents and pulsed-field gel electrophoresis ( PFGE) of these strains were analyzed to find the relationship among those isolates Clustering analysis was made from the patterns. Some isolates with high homology was found in 19 MRSA, 11 of them belong to type A, and 8 of them belong to the same subtype A1. They were endemic in burn ward, oncological ward and ICU. In addition, 4 isolates were clustered into group B, all found in the same ward of burn unit Thus, our results indicated a outbreak of MRSA ( A type) in this hospital and the potential prevalence of MRSA (B type) , which might be mediated by health care stuff. It is essential to enhance the infection control implementation and to utilize the PFGE genotyping system for the real-time surveillance of MRSA.