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ORIGINAL RESEARCH article

Front. Cell. Infect. Microbiol.
Sec. Bacteria and Host
Volume 14 - 2024 | doi: 10.3389/fcimb.2024.1411658
This article is part of the Research Topic Pathogenesis and Antimicrobial Resistance in Gram-negative Bacteria View all 5 articles

Molecular epidemiology of string test-positive Klebsiella pneumoniae isolates in Huzhou, China, 2020-2023

Provisionally accepted
Wei Yan Wei Yan Deshun Xu Deshun Xu *Yuehua Shen Yuehua Shen *Fenfen Dong Fenfen Dong *Lei Ji Lei Ji *
  • Huzhou center for disease control and prevention, Huzhou, China

The final, formatted version of the article will be published soon.

    Objective: This study used whole-genome sequencing (WGS) to explore the genetic diversity, virulence factors, and antimicrobial resistance determinants of string test-positive Klebsiella pneumoniae (KP) over a 4-year surveillance period in Huzhou, China. Methods: In total, 632 clinical isolates were collected via hospital surveillance from 2020 to 2023; 100 were positive in the string test and these 100 strains were subjected to antimicrobial susceptibility testing using an agar dilution method followed by WGS. Results: The resistance rates to cefotaxime (77.0%), trimethoprim-sulfamethoxazole (67.0%), and nalidixic acid (64.0%) were high. Multilocus sequence typing revealed high genetic diversity; there were 33 sequence types (STs) and 15 capsular serotypes. The most common ST was ST23 (16.0%) and the most common capsular serotype was K1 (22.5%). Virulome analysis revealed among-strain differences in virulence factors that affected bacterial adherence, efflux pump action, iron uptake, nutritional factors, metabolic regulation, the secretion system, and toxin production. The Kleborate strain-specific virulence scores of all 100 string test-positive KPs were derived; 28 strains scored 5, 28 scored 4, 21 scored 3, 12 scored 1, and 11 scored 0. All 77 strains with scores of 3 to 5 contained the iucA gene. The phylogeny based on whole-genome single nucleotide polymorphisms (wgSNPs) indicated high clonality; the string test-positive KP strains were grouped into six clades. Closely related isolates in each genetic cluster usually shared STs. Conclusions: The present study highlights the significance of the KP iucA gene in terms of hypervirulence, and the diverse genotypes of string test-positive KP strains isolated in Huzhou hospitals.

    Keywords: string test-positive KP, Hypermucoviscosity, Virulence, whole genome sequencing, Molecular Epidemiology

    Received: 03 Apr 2024; Accepted: 15 Jul 2024.

    Copyright: © 2024 Yan, Xu, Shen, Dong and Ji. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Deshun Xu, Huzhou center for disease control and prevention, Huzhou, China
    Yuehua Shen, Huzhou center for disease control and prevention, Huzhou, China
    Fenfen Dong, Huzhou center for disease control and prevention, Huzhou, China
    Lei Ji, Huzhou center for disease control and prevention, Huzhou, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.