Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
J Glob Antimicrob Resist. 2023 Dec;35:11-18. doi: 10.1016/j.jgar.2023.08.009. Epub 2023 Aug 20.
Hypervirulent Klebsiella pneumoniae (hvKp) and Klebsiella variicola (hvKv) cause hospital/community-acquired infections, often associated with antimicrobial resistance (AMR). This study aimed to investigate the molecular epidemiology of hvKp and hvKv in northern Japan.
A total of 500 K. pneumoniae and 421 K. variicola clinical isolates collected from August to December 2021 were studied. Prevalence of virulence factor-encoding genes, wzi sequence and associated K/KL type, sequence type (ST), and beta-lactamases and their types were characterized.
Any virulence gene (rmpA, rmpA2, peg-344, iucA, iutA, and iroB) and/or magA was detected in 25% (n = 125) of K. pneumoniae and 1% (n = 5) of K. variicola. Among these hvKp/hvKv, 22 wzi types (18 and 4 types, respectively) and 24 STs (20 and 4 STs, respectively) were identified. Sequence types of hvKp were classified into some clonal groups (CGs), among which CG35, including six STs, was the most common (n = 59; 47%), followed by CG23, and CG65. ST268 (CG35) associated with wzi95-K20 or wzi720 was the dominant lineage (n = 43, 34%), while K1:ST23/ST249 and K2:ST65/ST86 accounted for 26% and 13% of hvKp, respectively. Extended-spectrum beta-lactamase (ESBL) genes (blaCTX-M-2, blaCTX-M-3, blaCTX-M-15, and blaCTX-M-27) were detected in only ST23 and CG35 (ST268 and ST412) hvKp. No isolate was resistant to carbapenems, without detection of the ESBL gene in K. variicola. Phylogenetically, wzi was differentiated into two main clusters of K. pneumoniae and K. variicola. A major clonal group CG347 was identified in K. variicola.
Clonal structures were revealed for hvKp and hvKv clinical isolates with their AMR status in northern Japan.
产超广谱β-内酰胺酶（ESBL）的肺炎克雷伯菌（hvKp）和变异肺炎克雷伯菌（hvKv）引起医院/社区获得性感染，常伴有抗生素耐药性（AMR）。本研究旨在调查日本北部 hvKp 和 hvKv 的分子流行病学。
研究共收集了 2021 年 8 月至 12 月期间的 500 株肺炎克雷伯菌和 421 株变异肺炎克雷伯菌临床分离株。对毒力因子编码基因、wzi 序列及相关 K/KL 型、序列型（ST）、β-内酰胺酶及其类型进行了特征分析。
在 25%（n=125）的肺炎克雷伯菌和 1%（n=5）的变异肺炎克雷伯菌中检测到任何毒力基因（rmpA、rmpA2、peg-344、iucA、iutA 和 iroB）和/或 magA。在这些 hvKp/hvKv 中，鉴定出 22 种 wzi 型（分别为 18 和 4 种）和 24 种 ST（分别为 20 和 4 种）。hvKp 的序列型分为一些克隆群（CG），其中 CG35 包括 6 种 ST，最为常见（n=59；47%），其次是 CG23 和 CG65。与 wzi95-K20 或 wzi720 相关的 ST268（CG35）是主要谱系（n=43，34%），而 K1:ST23/ST249 和 K2:ST65/ST86 分别占 hvKp 的 26%和 13%。仅在 ST23 和 CG35（ST268 和 ST412）hvKp 中检测到扩展谱β-内酰胺酶（ESBL）基因（blaCTX-M-2、blaCTX-M-3、blaCTX-M-15 和 blaCTX-M-27）。没有耐碳青霉烯的分离株，在变异肺炎克雷伯菌中未检测到 ESBL 基因。在系统发育上，wzi 分为肺炎克雷伯菌和变异肺炎克雷伯菌的两个主要聚类。在变异肺炎克雷伯菌中发现了一个主要的克隆群 CG347。
揭示了日本北部 hvKp 和 hvKv 临床分离株的克隆结构及其 AMR 状况。
