School of Public Health, China Medical University, Shenyang, Liaoning, China.
Department of Emergency Response, Chinese People's Liberation Army Center for Disease Control and Prevention, Beijing, China.
Front Cell Infect Microbiol. 2023 Jan 4;12:1063406. doi: 10.3389/fcimb.2022.1063406. eCollection 2022.
Hypermucoviscous (HmKp) poses an emerging and highly pathogenic global health threat. This study aimed to investigate the clinical and genomic characteristics of HmKp isolates to better understand the virulence mechanisms of the hypermucoviscous (HMV) phenotype.
From May 2018 to August 2021, 203 non-repeat isolates causing invasive infections were collected from a hospital in Beijing, China. Isolates were divided into HmKp (n=90, 44.3%) and non-HmKp (n=113, 55.7%) groups according to string test results.
Multivariate regression showed that diabetes mellitus (odds ratio [OR]=2.20, 95% confidence interval (CI): 1.20-4.05, =0.010) and liver abscess (OR=2.93, CI 95%:1.29-7.03, =0.012) were associated with HmKp infections. was highly diverse, comprising 87 sequence types (STs) and 54 serotypes. Among HmKp isolates, ST23 was the most frequent ST (25/90, 27.8%), and the most prevalent serotypes were KL2 (31/90, 34.4%) and KL1 (27/90, 30.0%). Thirteen virulence genes were located on the capsular polysaccharide synthesis region of KL1 strains. HmKp isolates were sensitive to multiple antibiotics but carried more -type extended spectrum β-lactamase (ESBL) resistance genes (<0.05), suggesting that the emergence of ESBL-mediated multidrug resistance in HmKp should be monitored carefully during treatment. Phylogenetic analysis disclosed that HmKp isolates were highly diverse. Comparative genomic analysis confirmed that the HMV phenotype is a plasmid-encoded virulence factor. Seventeen HmKp genes were highly associated with HmKp, and included , 7 iron-acquisition-related genes, and , which may promote liver abscess formation.
This investigation provides insight into the mechanisms producing the HMV phenotype.
高粘性（HmKp）构成了一种新兴的、具有高度致病性的全球健康威胁。本研究旨在研究 HmKp 分离株的临床和基因组特征，以更好地了解高粘性（HMV）表型的毒力机制。
本研究从 2018 年 5 月至 2021 年 8 月，共收集了 203 株来自中国北京一家医院的引起侵袭性感染的非重复株。根据 string 试验结果，将分离株分为 HmKp（n=90，44.3%）和非 HmKp（n=113，55.7%）组。
多变量回归显示，糖尿病（比值比[OR]=2.20，95%置信区间[CI]：1.20-4.05，=0.010）和肝脓肿（OR=2.93，CI 95%：1.29-7.03，=0.012）与 HmKp 感染相关。 具有高度多样性，包括 87 个序列型（ST）和 54 个血清型。在 HmKp 分离株中，ST23 是最常见的 ST（25/90，27.8%），最常见的血清型是 KL2（31/90，34.4%）和 KL1（27/90，30.0%）。13 个毒力基因位于 KL1 株的荚膜多糖合成区。HmKp 分离株对多种抗生素敏感，但携带更多的 - 型扩展谱β-内酰胺酶（ESBL）耐药基因（<0.05），提示在治疗过程中应密切监测 HmKp 中 ESBL 介导的多药耐药的出现。系统发育分析表明，HmKp 分离株具有高度多样性。比较基因组分析证实，HMV 表型是一种质粒编码的毒力因子。17 个 HmKp 基因与 HmKp 高度相关，包括 ，7 个铁摄取相关基因，和 ，这可能促进肝脓肿的形成。
本研究提供了产生 HMV 表型的机制的见解。
