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Genetic features of the widespread plasmid coding for the carbapenemase OXA-48

Laurent Poirel1, Rémy A Bonnin, Patrice Nordmann

  • 1Service de Bactériologie-Virologie, INSERM U914, Emerging Resistance to Antibiotics, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, Faculté de Médecine et Université Paris-Sud, K.-Bicêtre, France.

Antimicrobial Agents and Chemotherapy
|November 16, 2011
PubMed

Insights

The OXA-48 carbapenemase gene, found on the pOXA-48a plasmid in Klebsiella pneumoniae, has spread globally. This plasmid lacks other antibiotic resistance genes, highlighting a specific threat in antimicrobial resistance.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • The bla(OXA-48) gene confers resistance to carbapenem antibiotics.
  • Carbapenem resistance is a significant global health threat.
  • Plasmid-mediated resistance facilitates rapid dissemination of antimicrobial resistance genes.

Purpose of the Study:

  • To fully sequence the pOXA-48a plasmid carrying the bla(OXA-48) gene.
  • To investigate the genetic structure and origin of the pOXA-48a plasmid.
  • To assess the prevalence and spread of pOXA-48a and related plasmids.

Main Methods:

  • Whole-genome sequencing of the pOXA-48a plasmid from a Klebsiella pneumoniae isolate.
  • Bioinformatic analysis to determine plasmid backbone and gene integration.
  • Molecular epidemiology using a collection of international OXA-48-producing bacterial isolates.

Main Results:

  • Complete sequencing revealed pOXA-48a is an IncL/M-type plasmid.
  • The bla(OXA-48) gene was integrated via the Tn1999 composite transposon.
  • No other antibiotic resistance genes were found on the pOXA-48a plasmid.
  • Molecular epidemiology confirmed the widespread international distribution of pOXA-48a or similar plasmids.

Conclusions:

  • The pOXA-48a plasmid is a key vehicle for the dissemination of the OXA-48 carbapenemase.
  • The Tn1999 transposon facilitated the acquisition of bla(OXA-48) into a common plasmid backbone.
  • The global spread of pOXA-48a poses a significant challenge for infection control and treatment strategies.

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