多重耐药鲍曼不动杆菌中仅黏菌素敏感菌株的分子流行病学研究

目的从基因水平了解多重耐药鲍曼不动杆菌（MDR-AB）中仅黏菌素敏感鲍曼不动杆菌（COS-AB）的流行情况，为控制其流行暴发提供实验数据。方法收集并分析上海瑞金医院2004年6月至2005年5月136例COS—AB临床感染患者的临床资料，同时收集2004年5月至2004年12月临床分离的鲍曼不动杆菌66株，其中COS-AB33株，非黏菌素敏感鲍曼不动杆菌（non-COS-AB）33株，采用随机引物PCR（RAPD）和脉冲场凝胶电泳（PFGE）等分子流行病学方法和统计学方法分析其流行情况。结果证实2004年6月至2005年5月出现COS-AB的暴发流行，经RAPD（引物ERIC2、272）分型均为一个型别，而PFGE分型为两个型别，其中烧伤科COS-AB为PFGEB型，为单一克隆的科室内流行；而烧伤科以外的其他科室为A型，为科室间流行，且主要集中于外科系统。结论COS-AB交叉感染严重，应严格消毒隔离措施，加强对COS-AB在环境及患者中流行情况的严密监测。用PFGE对鲍曼不动杆菌进行分型更为精确。

Molecular epidemiological study of colistin-only-sensitive strains of multi-drug resistant Acinetobacter baumannii

Objective To genetically analyze the epidemiology of the colistin-only-sensitive (COS) Acinetobacter baumannii (COS-AB) so as to provide experimental data for controlling COS-AB infection. Methods The drug resistance to 14 antibiotics of 136 COS-AB isolates collected in Ruijin Hospital from June 2004 to May 2005 were analyzed. 66 A. baumannii isolates were collected from May to December 2004, of which 33 strains were COS-AB and the other 33 non-COS-AB. Random amplified polymorphic DNA (RAPD) and pulsed-field gel electrophotesis (PFGE) were applied to analyze the homology of these strains. Results RAPD analysis (with the primers ERIC2 and 272) showed all COS-AB strains as identical, while PFGE analysis showed that these COS-AB were of two closely related genotypes distinctly different from that of the non-COS-AB. The COS-AB strains obtained from the Burns Ward were PFGE B type causing inter-ward outbreak of single clone. And the COS-AB strains obtained from another wards were PFGE BA type causing inter-departmental outbreak, mainly among the departments of surgical system. Conclusion The cross-infection of COS-AB is severe. Strict disinfection and sterilization should be implemented. The epidemiology of COS-AB in environment and patients should be closely monitored. PFGE analysis is a more accurate method in typing A. baumannii.