Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Lisbon, Portugal.
Laboratory Medical Microbiology, Department of Veterinary Sciences, CITAB-Centre for the Research and Technology Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.
J Glob Antimicrob Resist. 2020 Sep;22:349-353. doi: 10.1016/j.jgar.2020.04.007. Epub 2020 Apr 27.
To provide, for the first time, data on the molecular epidemiology of carbapenemase-producing Klebsiella pneumoniae clinical isolates from the northern region of Portugal (Trás-os-Montes and Alto Douro).
A total of 106 carbapenemase-producing K. pneumoniae isolates recovered from clinical samples and rectal swabs between January 2018 and March 2019 were included in this study. All isolates were characterized by antimicrobial susceptibility, identification of resistance determinants, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and plasmid analysis.
The most common carbapenemase identified was KPC-2 (91%), followed by OXA-48 (9%). The bla gene was carried onto IncN (60%) and IncF (40%) plasmid types, whereas the bla gene was mainly located on the IncL (90%) incompatibility group. Molecular characterization distributed the 106 isolates into 29 PFGE types and 21 sequence types (STs), but three clones included 50% of the isolates: PFGE A-ST147-KPC-2 (29%), B-ST15-KPC-2 (15%), and C-ST11-OXA-48 (6%). Antimicrobial resistance rates were the following: ciprofloxacin (76%), trimethoprim-sulfamethoxazole (75%), tobramycin (62%), gentamicin (34%), amikacin (25%), tigecycline (21%), fosfomycin (10%), and colistin (7%). None of the colistin-resistant isolates harboured mcr genes. All isolates remained susceptible to ceftazidime/avibactam, but 10% presented elevated MICs (3 and 4mg/L).
KPC-2 was the predominant carbapenemase among K. pneumoniae isolates currently circulating at this hospital from northern Portugal, followed by OXA-48. These data contrast with those obtained from the rest of the country, where KPC-3 predominates. This study showed a polyclonal structure of KPC-2-producing K. pneumoniae isolates with a predominance of the ST147 and ST15 clones.
首次提供葡萄牙北部（特茹河地区和上杜罗地区）产碳青霉烯酶肺炎克雷伯菌临床分离株的分子流行病学数据。
本研究纳入了 2018 年 1 月至 2019 年 3 月期间从临床样本和直肠拭子中分离的 106 株产碳青霉烯酶肺炎克雷伯菌。所有分离株均进行了药敏试验、耐药决定因子鉴定、脉冲场凝胶电泳（PFGE）、多位点序列分型（MLST）和质粒分析。
最常见的碳青霉烯酶是 KPC-2（91%），其次是 OXA-48（9%）。bla 基因位于 IncN（60%）和 IncF（40%）质粒类型，而 bla 基因主要位于 IncL（90%）不相容群。分子特征将 106 株分离株分为 29 种 PFGE 型和 21 种序列型（ST），但 3 个克隆包含了 50%的分离株：PFGE A-ST147-KPC-2（29%）、B-ST15-KPC-2（15%）和 C-ST11-OXA-48（6%）。药敏试验结果显示，这些分离株对环丙沙星（76%）、复方磺胺甲噁唑（75%）、妥布霉素（62%）、庆大霉素（34%）、阿米卡星（25%）、替加环素（21%）、磷霉素（10%）和黏菌素（7%）的耐药率较高。没有耐黏菌素的分离株携带 mcr 基因。所有分离株对头孢他啶/阿维巴坦仍保持敏感，但 10%的分离株 MIC 值升高（3mg/L 和 4mg/L）。
葡萄牙北部医院目前流行的肺炎克雷伯菌产碳青霉烯酶以 KPC-2 为主，其次是 OXA-48。与葡萄牙其他地区的数据相比，KPC-3 更为常见。本研究显示了产 KPC-2 肺炎克雷伯菌分离株的多克隆结构，以 ST147 和 ST15 克隆为主。
