【摘要】 目的分析耐碳青霉烯类抗生素鲍曼不动杆菌基因型,进行同源性分析,探讨碳青霉烯类抗生素耐药率升高的原因。方法应用WHONET5.0分析广州医学院第一附属医院重症监护病房(ICU)分离的鲍曼不动杆菌耐药率变化。收集2008年1月至2009年12月ICU碳青霉烯类抗生素耐药鲍曼不动杆菌35株,应用VITEK-2全自动细菌鉴定仪进行菌株鉴定,采用K-B纸片扩散法测定15种抗菌药物的敏感性,PCR检测金属β内酰胺酶及碳青霉烯酶OXA基因,脉冲场凝胶电泳(PFGE)分析同源性。结果该院分离的鲍曼不动杆菌对碳青霉烯类抗生素的耐药率显著增加,对美罗培南的耐药率从10.8%升高到62.3%,对亚胺培南的耐药率从13.5%升高到58.8%。PFGE分析存在8个克隆;blaOXA-51、blaOXA-23、blaOXA-58阳性的分别为33株(94.3%)、20株(57.1%)和6株(17.1%)。ISAba1相关blaOXA-23是碳青霉烯酶主要的存在形式。未检测到金属β内酰胺酶。结论该院ICU分离的鲍曼不动杆菌OXA-23型碳青霉烯酶基因检出率最高,并存在交叉感染的情况,应引起临床重视。更多还原

【Abstract】 Objective To analyze the carbapenemase genotypes and homogeneity among the isolates of Acinetobacter baumannii,and identify the factors contributing to the increasing carbapenem resistance.MethodsWHONET 5.0 software was used to analyze the changing prevalence of antibiotic resistance.Thirty-five carbapenem-resistant A.baumannii isolates were collected from an Intensive Care Unit between 2008 and 2009.All strains were identified by VITEK-2 and tested by Kirby-Bauer disk diffusion test.The carbapenemases and their relationship with ISAba1,metallo-β-lactamases genes were analyzed by PCR.Genotyping were conducted by pulsed-field gel electrophoresis.ResultsThe prevalence of meropenem-resistant strains increased rapidly from 10.8% to 62.3%,and imipenem-resistant strains increased from 13.5% to 58.8%.Eight clones were identified in the 35 A.baumannii strains.The blaOXA-51,blaOXA-23,and blaOXA-58 genes were identified in 94.29%(33/35),57.14%(20/35) and 17.14%(6/35) of these A.baumannii strains,respectively.ISAba1-associated blaOXA-23 genes were prevalent in carbapenem-resistant A.baumannii.No metallo-β-lactamases gene was identified.ConclusionsOXA-type carbapenemases(mainly OXA-23) play an important role in carbapenem-resistant A.baumannii.Attention should be paid to the cross-infection and prevalence of carbapenem-resistant A.baumannii in ICU.更多还原