Department of Medical Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Antimicrob Resist Infect Control. 2024 Oct 11;13(1):123. doi: 10.1186/s13756-024-01478-2.
The dissemination of Klebsiella spp. producing multiple carbapenemases has been increasingly recognized. Between July 2019 and August 2021, ten patients were found to carry Klebsiella spp. co-harboring bla and bla across multiple wards at a Korean hospital, and one isolate was recovered from a hand-washing sink, more than a year after the outbreak. This study aimed to investigate the outbreak and conduct a genomic study of these isolates.
Whole-genome sequencing, including long-read sequencing, was performed to analyze plasmid structures and mobile genetic elements (MGEs). Bioinformatics analyses were performed to trace clonal transmission chains and horizontal gene transfer.
The findings suggested that the inter-ward spread of Klebsiella spp. seemed to be facilitated by healthcare worker contact or patient movement. Of the nine isolates collected (eight clinical and one environmental), seven (including the environmental isolate) were identified as K. pneumoniae (ST3680) and two were K. variicola (single-locus variant of ST5252). These isolates showed high genetic relatedness within their species and harbored the IncHI5B plasmid carrying both bla and bla (pKPCVIM.1). On this plasmid, bla was located in the Class 1 integron associated with IS1326::IS1353 (In2), and Tn4401b carrying bla was inserted into IS1326::IS1353, creating a novel MGE construct (In2_bla-Tn4401b_bla).
The hospital-wide spread of bla and bla was facilitated by clonal spread and horizontal plasmid transfer. The persistence of this strain in the hospital sink suggests a potential reservoir of the strain. Understanding the transmission mechanisms of persistent pathogens is important for improving infection control strategies in hospitals.
产多种碳青霉烯酶的肺炎克雷伯菌的传播越来越受到关注。2019 年 7 月至 2021 年 8 月，韩国一家医院的多个病房共发现 10 例携带 bla 和 bla 的肺炎克雷伯菌患者，其中 1 例是在疫情爆发一年多后从洗手池回收的。本研究旨在调查此次疫情，并对这些分离株进行基因组研究。
对包括长读测序在内的全基因组测序进行分析，以研究质粒结构和移动遗传元件（MGE）。采用生物信息学分析追踪克隆传播链和水平基因转移。
研究结果表明，医护人员接触或患者移动可能促进了病房之间肺炎克雷伯菌的传播。在所收集的 9 个分离株（8 个临床分离株和 1 个环境分离株）中，7 个（包括环境分离株）被鉴定为肺炎克雷伯菌（ST3680），2 个为肺炎克雷伯菌变异菌（ST5252 的单一位点变体）。这些分离株在其种内具有高度遗传相关性，携带 IncHI5B 质粒，该质粒同时携带 bla 和 bla（pKPC-VIM.1）。在该质粒上，bla 位于与 IS1326::IS1353（In2）相关的 1 类整合子中，Tn4401b 携带 bla 插入 IS1326::IS1353，形成一种新的 MGE 构建体（In2_bla-Tn4401b_bla）。
bla 和 bla 的医院内传播是由克隆传播和水平质粒转移促成的。该菌株在医院水槽中的持续存在提示了该菌株的潜在储库。了解持久性病原体的传播机制对于改进医院感染控制策略非常重要。
