Emergence of multidrug-resistant E. coli ST8346 isolates carrying three distinct plasmids with NDM-5, KPC-2, and OXA-181

J Infect Public Health. 2024 Dec;17(12):102596. doi: 10.1016/j.jiph.2024.102596. Epub 2024 Nov 16.

Abstract

Background: E. coli ST8346 is a unique strain associated with the potential carriage of multiple carbapenemases. Three unique E. coli ST8346 isolates were identified, each concurrently harboring multiple carbapenemases, including blaNDM-5, blaKPC-2, and/or blaOXA-181. This study aimed to characterize the genetic and plasmid structures of these isolates to understand their transmission and resistance mechanisms.

Methods: Antibiotic resistance profiles, genetic relatedness, and plasmid structures were determined using antibiotic susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), S1 nuclease PFGE, and long-read sequencing.

Results: All the strains were carbapenem resistant. PFGE revealed close genetic relationships among the isolates, despite the lack of geographical or epidemiological connections. blaNDM-5, blaKPC-2, and blaOXA-181 were located on separate plasmids. Plasmids harboring blaNDM-5 showed genetic similarities to blaNDM-5-bearing IncF plasmids in the United Kingdom. The IncA/C plasmids harboring blaKPC-2 had identical sequences resembling a plasmid from a K. pneumoniae strain in Taiwan, except for the blaKPC-2 region, which matched a strain from China, indicating a hybrid plasmid.

Conclusion: This study is the first to identify and characterize the coexistence of blaNDM-5, blaKPC-2, and blaOXA-181 in E. coli ST8346 isolates. The spread appears to be due to independent acquisition events. We identified the putative origins of these plasmids and detected a possible recombination event in a novel IncA/C plasmid. These findings emphasize the importance of ongoing surveillance and further investigations.

Keywords: Carbapenemase; E. coli ST8346; KPC-2; NDM-5; OXA-181; Plasmid.

MeSH terms

  • Aged
  • Anti-Bacterial Agents / pharmacology
  • Drug Resistance, Multiple, Bacterial* / genetics
  • Electrophoresis, Gel, Pulsed-Field
  • Escherichia coli Infections* / microbiology
  • Escherichia coli Proteins* / genetics
  • Escherichia coli* / drug effects
  • Escherichia coli* / genetics
  • Escherichia coli* / isolation & purification
  • Female
  • Humans
  • Male
  • Microbial Sensitivity Tests*
  • Middle Aged
  • Multilocus Sequence Typing*
  • Plasmids* / genetics
  • beta-Lactamases* / genetics

Substances

  • beta-Lactamases
  • Escherichia coli Proteins
  • beta lactamase NDM-5, E coli
  • beta-lactamase KPC-2
  • Anti-Bacterial Agents
  • beta-lactamase OXA-181, E coli