Wroblewska M M, Towner K J, Marchel H, Luczak M
Department of Medical Microbiology, Central Clinical Hospital, Medical University of Warsaw, Warsaw, Poland.
Clin Microbiol Infect. 2007 May;13(5):490-6. doi: 10.1111/j.1469-0691.2007.01694.x. Epub 2007 Feb 28.
This study analysed the occurrence of carbapenem resistance among Acinetobacter baumannii isolates from a tertiary-care hospital in Poland, together with the molecular epidemiology of these isolates and the risk-factors for their acquisition and possible nosocomial spread. The medical charts of 21 patients with Acinetobacter infection or colonisation revealed that A. baumannii isolates were obtained most frequently from intensive care unit and surgical patients (particularly those receiving transplantation surgery). First isolation occurred, on average, on day 21 following admission (range 5-45 days). Infection with Acinetobacter contributed directly to the death of seven patients. Several patients were infected with more than one strain, and molecular typing revealed the co-circulation of three predominant clones, of which two belonged to the Acinetobacter lineages designated as European clones I and II. All three clones encoded an OXA-51-type carbapenemase, but were negative for carbapenemases belonging to the OXA-23, OXA-24 and OXA-58 families. The OXA-51 gene was found in both resistant and susceptible isolates, and was not associated directly with carbapenem resistance. Etests with imipenem and imipenem plus EDTA indicated production of a metallo-beta-lactamase (MBL) in carbapenem-resistant isolates. PCRs for IMP-type MBLs were negative, but PCR using consensus primers for VIM-type MBLs were positive for carbapenem-resistant isolates belonging to the European clone II lineage. The occurrence of a VIM-type MBL in association with one of the epidemic lineages of A. baumannii is a cause for concern. Further studies are needed to evaluate possible inter-hospital spread of resistant A. baumannii strains in Poland.
本研究分析了波兰一家三级护理医院鲍曼不动杆菌分离株中碳青霉烯耐药性的发生情况，以及这些分离株的分子流行病学、获得耐药性及可能的医院内传播的危险因素。21例鲍曼不动杆菌感染或定植患者的病历显示，鲍曼不动杆菌分离株最常从重症监护病房患者和外科患者（尤其是接受移植手术的患者）中获得。首次分离平均发生在入院后第21天（范围为5 - 45天）。鲍曼不动杆菌感染直接导致7例患者死亡。有几名患者感染了不止一种菌株，分子分型显示有三个主要克隆共同流行，其中两个属于被指定为欧洲克隆I和II的鲍曼不动杆菌谱系。所有三个克隆均编码OXA - 51型碳青霉烯酶，但对属于OXA - 23、OXA - 24和OXA - 58家族的碳青霉烯酶呈阴性。在耐药和敏感分离株中均发现了OXA - 51基因，且它与碳青霉烯耐药性无直接关联。亚胺培南及亚胺培南加EDTA的E试验表明，碳青霉烯耐药分离株产生了金属β-内酰胺酶（MBL）。针对IMP型MBL的PCR检测为阴性，但使用VIM型MBL通用引物进行的PCR检测显示，属于欧洲克隆II谱系的碳青霉烯耐药分离株呈阳性。VIM型MBL与鲍曼不动杆菌的一个流行谱系相关的情况令人担忧。需要进一步研究以评估波兰耐药鲍曼不动杆菌菌株可能在医院间的传播情况。
