Objective: To identify the epidemic clones of MRSA isolates at a hospital in shanghai. Methods: A total of 72 MRSA isolates have been isolated from a second grade hospital between 2017 and 2018, including 32 CA-MRSA isolates, 13 HA-MRSA isolates and 26 MRSA isolates from environment. In this study, MLST and PFGE typing methods were used to analyze the molecular epidemiology of the MRSA isolates. Results: A total of 72 MRSA isolates have been obtained including 46 isolates from clinical specimens, 26 isolates from environments. The 46 MRSA isolates from clinical specimens consisted of 33 CA-MRSA (community-acquired MRSA) and 13 HA-MRSA (hospital-acquired MRSA). Furthermore, these patients infected with MRSA isolates were mostly distributed in the department of geriatrics (34.8%, 16/46), internal medicine (26.1%, 12/46) and surgery (26.1%, 12/46). MLST typing results showed that ST764 was predominant in isolates from both clinical specimens and hospital environments. Furthermore, PFGE typing results showed that most ST764 MRSA had high homolog (>90%). Conclusion: ST764 MRSA isolates might spread in community, hospital and environments. Therefore, continuous monitoring of MRSA and its variation may be useful in understanding the involvement of epidemic clone, and in searching new strategies to control MRSA infection.
目的： 分析上海市某医院中不同来源耐甲氧西林金黄色葡萄球菌（MRSA）的分子生物学特征，明确上海某医院MRSA的流行特点。 方法： 收集上海市某二甲医院2017—2018年期间72株MRSA,综合应用多位点序列分型（MLST）、脉冲场凝胶电泳（PFGE）分型方法对MRSA菌株进行分子生物学特征分析。 结果： 72株MRSA中，46株分离自临床病例，26株分离自医院环境。46株临床分离菌株包括33株社区获得性MRSA（CA-MRSA），以及13株医院获得性MRSA（HA-MRSA），且来自医院的不同的病区。感染MRSA的住院患者所在科室以老年科（34.8%，16株）、内科（26.1%，12株）和外科（26.1%，12株）为主。MLST分型结果显示，不同来源MRSA菌株的ST型差别较大，但ST764是不同来源的MRSA菌株的优势克隆群（40.3%，29株），且PFGE聚类结果显示12株不同来源的ST764型MRSA菌株具有较高的同源性（>90%）。 结论： ST764型MRSA可能在社区、医院及环境中存在播散，应持续监测MRSA及其变异情况。.
Keywords: Methicillin-resistant Staphylococcus aureus; Multilocus sequencing typing; Pulsed fieldgel electrophoresis.