Department of Microbiology and Clinical Microbiology, Medical Faculty, Zonguldak Karaelmas University, 67600 Zonguldak, Turkey.
Int J Antimicrob Agents. 2010 Aug;36(2):114-8. doi: 10.1016/j.ijantimicag.2010.03.017. Epub 2010 May 26.
The aim of this study was to characterise the molecular epidemiology and mechanisms of carbapenem resistance of nosocomial Acinetobacter baumannii isolates in a new university hospital in Turkey. A total of 145 carbapenem-resistant A. baumannii (CRAB) isolates were collected during the period 2003-2006. All isolates were typed by amplified fragment length polymorphism (AFLP) analysis. AFLP analysis showed three predominant clusters consisting of 72, 20 and 12 clinical strains as well as some smaller clusters and 23 unique strains. The three main clonal AFLP types corresponded to three major antibiotic susceptibility patterns. One environmental isolate was found related to the major outbreak clone. The reference type strains of European clones I, II and III were also typed by AFLP and analysed for clonal similarity. Polymerase chain reaction (PCR) analysis of different carbapenem resistance genes showed that strains from each of the three main clusters as well as 79% of the remaining strains harboured the bla(OXA-58) gene. No genes encoding the metallo-beta-lactamases GIM-1, SIM-1, SPM-1, IMP-like and VIM-like or the oxacillinases OXA-24-like and OXA-23-like were detected. In conclusion, multiple clones of CRAB strains producing OXA-58-type oxacillinase were responsible for a sustained CRAB outbreak occurring in a hospital in Turkey. These isolates were not associated with A. baumannii strains of the major European clones I, II or III.
本研究旨在对土耳其一所新大学医院的医院获得性鲍曼不动杆菌碳青霉烯耐药株的分子流行病学和耐药机制进行分析。在 2003-2006 年期间共收集了 145 株碳青霉烯耐药的鲍曼不动杆菌（CRAB）。所有分离株均通过扩增片段长度多态性（AFLP）分析进行分型。AFLP 分析显示存在三个主要聚类，包括 72、20 和 12 株临床分离株，以及一些较小的聚类和 23 株独特的分离株。三种主要的克隆 AFLP 类型与三种主要的抗生素敏感性模式相对应。一个环境分离株与主要暴发克隆有关。欧洲克隆 I、II 和 III 的参考株也通过 AFLP 进行了分型，并对其克隆相似性进行了分析。不同碳青霉烯耐药基因的聚合酶链反应（PCR）分析显示，三个主要聚类中的菌株以及其余 79%的菌株均携带 bla（OXA-58）基因。未检测到编码金属β-内酰胺酶 GIM-1、SIM-1、SPM-1、IMP 样和 VIM 样或产 OXA-24 样和 OXA-23 样的基因。总之，产生 OXA-58 型β-内酰胺酶的 CRAB 菌株的多个克隆是导致土耳其一家医院发生持续的 CRAB 暴发的原因。这些分离株与欧洲主要克隆 I、II 或 III 的鲍曼不动杆菌菌株无关。
