da Rocha Letícia Fernandes, Rodrigues Grazielle Motta, de Oliveira Gabriela Simões, Echevarria Aymê Duarte, Wink Priscila, Volpato Fabiana, Berdichevski Mayana, Lutz Larissa, Pereira Dariane Castro, Barth Afonso Luís, Martins Andreza Francisco
Unidade de Microbiologia e Biologia Molecular, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
PPGCM - Programa de Pós-Graduação em Ciências Médicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Front Microbiol. 2025 Jul 2;16:1525543. doi: 10.3389/fmicb.2025.1525543. eCollection 2025.
is a significant causative agent of hospital-acquired infections (HAIs), particularly in intensive care units (ICUs). Carbapenem resistance represents a major concern in HAI management, as carbapenem-resistant bacteria can trigger outbreaks in hospital settings. While molecular evaluation of outbreaks typically relies on pulse field gel electrophoresis (PFGE) or core genome multilocus sequence typing (cgMLST) methods, alternative rapid, reliable, and cost-effective methods for assessing clonal relatedness are needed.
This study aimed to characterize a carbapenem-resistant outbreak that occurred during the COVID-19 pandemic in a tertiary care hospital, using the flagellin gene as a single-locus sequence typing (SLST) method. In addition, we evaluated the genetic context of carbapenemase genes through whole-genome sequencing (WGS).
Among the 170 carbapenem-resistant isolates recovered, high resistance to gentamicin, ciprofloxacin, and cefepime was observed. The predominant carbapenemase gene detected by qPCR-HRM was blaKPC (92.2%). Phylogenetic analysis of the flagellin gene grouped the sequences into two distinct clades, with all outbreak-related -positive isolates clustering within clade B. The gene was carried on an IncP6 plasmid.
Our findings indicate that the flagellin gene serves as an effective marker for characterizing carbapenem-resistant carrying , confirming that the outbreak was caused by the clonal expansion of isolates harboring on an IncP6 plasmid.
是医院获得性感染（HAIs）的重要病原体，尤其是在重症监护病房（ICUs）。碳青霉烯耐药性是医院获得性感染管理中的一个主要问题，因为耐碳青霉烯类细菌可在医院环境中引发疫情。虽然疫情的分子评估通常依赖于脉冲场凝胶电泳（PFGE）或核心基因组多位点序列分型（cgMLST）方法，但仍需要用于评估克隆相关性的快速、可靠且经济高效的替代方法。
本研究旨在利用鞭毛蛋白基因作为单一位点序列分型（SLST）方法，对一家三级医院在新冠疫情期间发生的耐碳青霉烯类疫情进行特征分析。此外，我们通过全基因组测序（WGS）评估了碳青霉烯酶基因的遗传背景。
在回收的170株耐碳青霉烯类分离株中，观察到对庆大霉素、环丙沙星和头孢吡肟的高耐药性。通过qPCR-HRM检测到的主要碳青霉烯酶基因是blaKPC（92.2%）。鞭毛蛋白基因的系统发育分析将序列分为两个不同的进化枝，所有与疫情相关的阳性分离株都聚集在进化枝B内。该基因位于IncP6质粒上。
我们的研究结果表明，鞭毛蛋白基因可作为表征携带耐碳青霉烯类的有效标记，证实该疫情是由携带IncP6质粒的分离株的克隆扩增引起的。
