1 Aix-Marseille Université , Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63, CNRS 7278, IRD 198, Inserm 1095, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Marseille, France .
Microb Drug Resist. 2014 Apr;20(2):156-61. doi: 10.1089/mdr.2013.0161. Epub 2013 Dec 9.
Infections caused by carbapenem-resistant Pseudomonas aeruginosa strains represent a major therapeutic and epidemiological problem. The aim of this study was to characterize carbapenem resistance in 89 clinical strains of P. aeruginosa isolated from three hospitals in western Algeria between October 2009 and November 2012. Minimum inhibitory concentrations (MICs) of imipenem were determined by the Etest method. Screening for metallo-β-lactamase (MβL) was performed using Etest MβL strips, and a PCR was conducted to detect carbapenemase-encoding genes. The amplification of the oprD gene followed by a sequencing reaction was performed for all strains resistant to imipenem. The clonality of 53 P. aeruginosa strains was demonstrated using multilocus sequence typing (MLST). Among the 89 isolates, 35 (39.33%) were found to be resistant to IMP (MICs ≥16 μg/ml). The blaVIM-2 gene was detected in two strains. The remaining imipenem-resistant isolates showed the presence of oprD mutations. The MLST analysis differentiated strains into various clones and the strains from the same clone had an identical sequence of the oprD gene. We report the second detection in 2010 of blaVIM-2 in Algerian P. aeruginosa strains. We also found that oprD mutations were the major determinant of high-level imipenem resistance. We demonstrate that these oprD mutations can be used as a tool to study the clonality in P. aeruginosa isolates.
耐碳青霉烯铜绿假单胞菌引起的感染是一个主要的治疗和流行病学问题。本研究的目的是描述 2009 年 10 月至 2012 年 11 月间，来自阿尔及利亚西部三家医院的 89 株临床分离铜绿假单胞菌对碳青霉烯类药物的耐药性特征。采用 Etest 法测定亚胺培南的最小抑菌浓度（MIC）。使用 Etest MβL 条带进行金属β-内酰胺酶（MβL）筛选，并用 PCR 检测碳青霉烯酶编码基因。对所有耐亚胺培南的菌株进行 oprD 基因扩增和测序反应。对 89 株分离株进行多基因序列分型（MLST）以证明 53 株铜绿假单胞菌的克隆性。在 89 株分离株中，35 株（39.33%）对 IMP（MICs≥16μg/ml）耐药。在 2 株菌中检测到 blaVIM-2 基因。其余耐亚胺培南的分离株显示 oprD 基因突变。MLST 分析将菌株分为不同的克隆，同一克隆的菌株具有相同的 oprD 基因序列。我们报道了 2010 年在阿尔及利亚铜绿假单胞菌中第二次检测到 blaVIM-2。我们还发现 oprD 突变是高水平亚胺培南耐药的主要决定因素。我们证明这些 oprD 突变可用作研究铜绿假单胞菌分离株克隆性的工具。
