Acinetobacter calcoaceticus–Acinetobacter baumannii complex (ACB) comprises some opportunistic pathogens associated with infectious outbreaks in hospital settings. A. baumannii is the most relevant species owing to its capacity to develop resistance to the different classes of antimicrobials. The aim of this study was to identify the species, establish the genetic patterns, resistance and biofilm profiles in ACB isolates associated with nosocomial infection in a hospital of Pelotas, Rio Grande do Sul, Brazil. Twenty-two clinical isolates were characterized at the species level through multiplex polymerase chain reaction (PCR) for the gyrB and blaOXA51-like genes, and the genetic relationship was determined through pulsed-field gel electrophoresis (PFGE). Their antibiotic resistance profiles and carbapenemases synthesis were evaluated following CLSI guidelines. PCR was carried out to evaluate the presence of carbapenemases genes and the isolates were classified for their biofilm-forming ability. All isolates obtained in the study were identified as A. baumannii and 72.7% of the isolates were classified as strong biofilm formers. In the class carbapenems, 95.4% and 77.3% of the isolates were resistant to meropenem and imipenem, respectively. The blaVIM gene was identified in 90.9% of isolates and carbapenemases synthesis were confirmed in 95.4% of the isolates. Fourteen genetic patterns were confirmed through PFGE analyses. The isolates collected within a time gap of 2 years demonstrated a genetic relationship, and the same clone was identified in different departments in the hospital. To the best of our knowledge, this is the first report of identification and characterization of A. baumannii nosocomial isolates in Pelotas, RS, Brazil.

中文翻译：

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耐碳青霉烯鲍曼不动杆菌的分子特征与巴西 Pelotas 医院感染相关

醋酸钙不动杆菌-鲍曼不动杆菌复合体 (ACB) 包含一些与医院环境中感染爆发相关的机会性病原体。A. baumannii 是最相关的物种，因为它能够对不同类别的抗微生物药物产生耐药性。本研究的目的是在巴西南里奥格兰德州佩洛塔斯的一家医院中鉴定与医院感染相关的 ACB 分离株中的物种，建立遗传模式、耐药性和生物膜特征。通过针对gyrB 和blaOXA51 样基因的多重聚合酶链反应(PCR) 在物种水平上表征了22 个临床分离株，并通过脉冲场凝胶电泳(PFGE) 确定了遗传关系。根据 CLSI 指南评估了它们的抗生素耐药性和碳青霉烯酶合成。进行 PCR 以评估碳青霉烯酶基因的存在，并根据其生物膜形成能力对分离物进行分类。研究中获得的所有分离株均被鉴定为鲍曼不动杆菌，72.7% 的分离株被归类为强生物膜形成菌。在碳青霉烯类中，95.4% 和 77.3% 的分离株分别对美罗培南和亚胺培南耐药。blaVIM 基因在 90.9% 的分离株中得到鉴定，碳青霉烯酶合成在 95.4% 的分离株中得到证实。通过 PFGE 分析确认了 14 种遗传模式。在2年的时间间隔内收集的分离株表现出亲缘关系，并且在医院的不同科室鉴定了相同的克隆。