Characterization of a Multidrug-Resistant Hypovirulent ST1859-KL35 Klebsiella quasipneumoniae subsp. similipneumoniae Strain Co-harboring tmexCD2-toprJ2 and bla_KPC-2.

IF 3.7 3区医学 Q2 INFECTIOUS DISEASES

Journal of global antimicrobial resistance Pub Date : 2025-03-18 DOI:10.1016/j.jgar.2025.03.009

Jiawei Ding, Mengying Zhang, Jiyong Chang, Zidan Hu, Pei He, Jia Wang, Lei Feng

{"title":"Characterization of a Multidrug-Resistant Hypovirulent ST1859-KL35 Klebsiella quasipneumoniae subsp. similipneumoniae Strain Co-harboring tmexCD2-toprJ2 and blaKPC-2.","authors":"Jiawei Ding, Mengying Zhang, Jiyong Chang, Zidan Hu, Pei He, Jia Wang, Lei Feng","doi":"10.1016/j.jgar.2025.03.009","DOIUrl":null,"url":null,"abstract":"Objectives: The rise of multidrug-resistant (MDR) Klebsiella pneumoniae is a significant public health threat. Klebsiella quasipneumoniae is often misidentified as K. pneumoniae, and its genetic and virulence traits remain underexplored. This study characterizes the genomic and phenotypic features of a K. quasipneumoniae subsp. similipneumoniae strain (KP24) .Methods: Antibiotic susceptibility was tested using microbroth dilution assay. Virulence was evaluated through serum killing assay and Galleria mellonella infection model. Whole genome sequencing (WGS) and bioinformatics analysis determined sequence typing, resistance profiles, and plasmid types. Conjugation assays assessed plasmid transferability, while phylogenetic analysis explored genetic relationships.Results: KP24 exhibited an MDR phenotype, including resistance to carbapenems, ceftazidime/avibactam, and tigecycline. KP24 showed significantly higher serum survival and G. mellonella lethality than ATCC700603, though it was less virulent than the hypervirulent strain NUTH-K2044. WGS identified KP24 as ST1859 and KL35, harboring the aerobactin virulence gene cluster (iucABCDiutA) and multiple resistance genes, including tmexCD2-toprJ2, blaKPC-2, blaOXA-10, blaIMP-4, and qnrS1. Notably, the tmexCD2-toprJ2 and blaKPC-2 genes were located on the same plasmid (pKP24-1) , an uncommon co-existence. Conjugation assays confirmed the independent transferability of pKP24-1 to Escherichia coli J53. Phylogenetic analysis revealed that ST1859 forms a distinct monoclade with low genetic diversity, closely related to ST334, suggesting regional expansion and potential global dissemination.Conclusions: KP24 represents a hypovirulent yet multidrug-resistant strain of K. quasipneumoniae subsp. similipneumoniae, with a concerning combination of virulence and resistance determinants. The co-location of tmexCD2-toprJ2 and blaKPC-2 on a transferable plasmid highlights the potential for horizontal gene transfer of critical resistance mechanisms.","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7000,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of global antimicrobial resistance","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.jgar.2025.03.009","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"INFECTIOUS DISEASES","Score":null,"Total":0}

引用次数: 0

Abstract

Objectives: The rise of multidrug-resistant (MDR) Klebsiella pneumoniae is a significant public health threat. Klebsiella quasipneumoniae is often misidentified as K. pneumoniae, and its genetic and virulence traits remain underexplored. This study characterizes the genomic and phenotypic features of a K. quasipneumoniae subsp. similipneumoniae strain (KP24) .

Methods: Antibiotic susceptibility was tested using microbroth dilution assay. Virulence was evaluated through serum killing assay and Galleria mellonella infection model. Whole genome sequencing (WGS) and bioinformatics analysis determined sequence typing, resistance profiles, and plasmid types. Conjugation assays assessed plasmid transferability, while phylogenetic analysis explored genetic relationships.

Results: KP24 exhibited an MDR phenotype, including resistance to carbapenems, ceftazidime/avibactam, and tigecycline. KP24 showed significantly higher serum survival and G. mellonella lethality than ATCC700603, though it was less virulent than the hypervirulent strain NUTH-K2044. WGS identified KP24 as ST1859 and KL35, harboring the aerobactin virulence gene cluster (iucABCDiutA) and multiple resistance genes, including tmexCD2-toprJ2, bla_KPC-2, bla_OXA-10, bla_IMP-4, and qnrS1. Notably, the tmexCD2-toprJ2 and bla_KPC-2 genes were located on the same plasmid (pKP24-1) , an uncommon co-existence. Conjugation assays confirmed the independent transferability of pKP24-1 to Escherichia coli J53. Phylogenetic analysis revealed that ST1859 forms a distinct monoclade with low genetic diversity, closely related to ST334, suggesting regional expansion and potential global dissemination.

Conclusions: KP24 represents a hypovirulent yet multidrug-resistant strain of K. quasipneumoniae subsp. similipneumoniae, with a concerning combination of virulence and resistance determinants. The co-location of tmexCD2-toprJ2 and bla_KPC-2 on a transferable plasmid highlights the potential for horizontal gene transfer of critical resistance mechanisms.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of global antimicrobial resistance INFECTIOUS DISEASES-PHARMACOLOGY & PHARMACY

CiteScore

8.70

自引率

2.20%

发文量

285

审稿时长

34 weeks

期刊介绍： The Journal of Global Antimicrobial Resistance (JGAR) is a quarterly online journal run by an international Editorial Board that focuses on the global spread of antibiotic-resistant microbes. JGAR is a dedicated journal for all professionals working in research, health care, the environment and animal infection control, aiming to track the resistance threat worldwide and provides a single voice devoted to antimicrobial resistance (AMR). Featuring peer-reviewed and up to date research articles, reviews, short notes and hot topics JGAR covers the key topics related to antibacterial, antiviral, antifungal and antiparasitic resistance.