Unité Environnement, Institut Pasteur d'Algérie, Alger 16000, Algeria.
Unité de Microbiologie, Institut Pasteur d'Algérie, Antenne d'Oran 31000, Algeria; Département de Biologie, Faculté des Sciences de la Nature et de la vie, Université Oran1, 31000, Algeria.
Sci Total Environ. 2018 Nov 15;642:90-94. doi: 10.1016/j.scitotenv.2018.05.387. Epub 2018 Jun 9.
Colistin is currently regarded as one of the 'last-resort' antibiotics used for the treatment of critical infections caused by multidrug-resistant Gram-negative pathogens. Recently, there have been numerous reports of the emergence of a transferable plasmid-mediated colistin resistance gene, mcr-1 in patients, animals, food, and environment. Here, we characterize the support of colistin resistance among environmental isolates collected from seawater of Algiers coast. Our study was carried out on 246 isolates resistant to colistin (MIC > 2 μg/L). The mcr-1 gene was identified in only two isolates; M49 and M78. The two strains were identified as Escherichia coli and were non-susceptible to amoxicillin, ticarcillin, piperacillin, gentamicin, nalidixic acid, tigecycline, tetracycline, trimethoprim-sulfamethoxazole and colistin. For the latter, isolates M49 and M78 showed MIC values of 4 μg/mL and 8 μg/mL, respectively. Only the strain M78 was intermediary resistant to tobramycin. The two E. coli strains belonged to two different sequence types (STs): ST23 for M49 and ST115 for M78. The mcr-1 gene was present on a non-conjugative plasmid in the two strains.
黏菌素目前被认为是治疗多重耐药革兰氏阴性病原体引起的严重感染的“最后手段”抗生素之一。最近，有大量关于可转移质粒介导的黏菌素耐药基因 mcr-1 在患者、动物、食品和环境中出现的报告。在这里，我们对来自阿尔及尔海岸海水的环境分离株中黏菌素耐药的支持情况进行了表征。我们的研究共涉及 246 株对黏菌素（MIC>2μg/L）耐药的分离株。仅在两株分离株中鉴定出 mcr-1 基因；M49 和 M78。这两种菌株被鉴定为大肠杆菌，对阿莫西林、替卡西林、哌拉西林、庆大霉素、萘啶酸、替加环素、四环素、复方磺胺甲噁唑和黏菌素均不敏感。对于后者，分离株 M49 和 M78 的 MIC 值分别为 4μg/mL 和 8μg/mL。只有菌株 M78 对妥布霉素呈中介耐药。这两株大肠杆菌菌株属于两个不同的序列型（ST）：M49 为 ST23，M78 为 ST115。mcr-1 基因存在于这两种菌株的非接合性质粒上。
