亚胺培南耐药鲍曼不动杆菌的耐药性及耐药基因型分析

摘要

目的 调查重庆医科大学附属第一医院临床分离的亚胺培南耐药鲍曼不动杆菌的耐药性特点及碳青霉烯酶基因型和16S rRNA甲基化酶分析.方法 收集2009年11月至2010年2月临床分离出耐亚胺培南的鲍曼不动杆菌菌株54株,经Vitek-2 Compact进行细菌鉴定、药敏实验及最小抑菌浓度(MIC)值测定;基因扩增仪(PCR)扩增碳青霉烯酶、16S rRNA甲基化酶耐药基因及其克隆测序.结果 54株耐亚胺培南的鲍曼不动杆菌均为多重耐药表型,全部都携带OXA-66基因,其中53株携带有OXA-23基因,全部53株菌都检测到OXA-23基因上游插入序列ISAbal,41株菌检测到16S rRNA甲基化酶armA基因阳性.结论 产OXA-23型碳青霉烯酶是鲍曼不动杆菌对亚胺培南耐药的最主要原因,其上游插入序列ISAbal 在耐药中起重要作用.%Objective To investigate the antimicrobial resistance , the carbapenemases and 16S rRNA methylases of imipenem-resistant Acinetobacter baumannii strains isolated from the first affiliated hospital of Chongqing medical university.Methods A total of 54 imipenem-resistant Acinetobacter baumannii strains were collected from December 2009 to January 2010 from clinic.The Vitek-2 Compact was used for identifying bacteria, susceptibility testing and determination of MJC values.Several carbapenemase genes and 16S rRNA methylase genes were detected by PCRbased assays and PCR products were sequented.Results All of the 54strains were multidrug resistance phenotype.All of the imipenem-resistant strains contained OXA-66 carbapenemase gene and 53strains were positive for OXA-23-like gene.OXA-23-like gene of 53 strains had an ISAbal sequence.41 armA-positive strains were identified.Conclusion Most of the imipenem-resistant Acinetobacter baumannii strains contained OXA-23 , with ISAbal upstream of the gene.16S rRNA methylase gene armA was widely distributed in these strains.