Ongoing dissemination of OXA-244 carbapenemase-producing Escherichia coli in Switzerland and their detection

Diagn Microbiol Infect Dis. 2020 Jul;97(3):115059. doi: 10.1016/j.diagmicrobio.2020.115059. Epub 2020 Apr 8.

Abstract

OXA-244 is a derivative of OXA-48 showing weaker carbapenemase activity, compromising the detection of corresponding producers in clinical laboratories. Since 2017, the Swiss National Reference Center for Emerging Antibiotic Resistance noticed an increased identification of OXA-244-producing Escherichia coli (n=15) within the country. Different methods (biochemical and immunoassay tests, screening culture media) were tested for the detection of OXA-244 producers. Whole genome sequencing was used to investigate the genetic relatedness between the isolates and the genetic structures at the origin of the acquisition of the blaOXA-244 gene. The mSuperCARBA® medium and the NG-Test CARBA5 assay were found to be suitable tools for detecting all OXA-244-producing isolates. Other selective media did not perform optimally. Among the fifteen strains, five sequence types were identified, with ST38 being predominant. The blaOXA-244 gene was located on the chromosome for all isolates. Overall, detection of OXA-244 producers is challenging and specific guidelines must be followed.

Keywords: Carbapenemase; Detection; OXA-244; OXA-48.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology
  • Bacterial Proteins / metabolism*
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Escherichia coli / isolation & purification*
  • Escherichia coli Infections / diagnosis
  • Escherichia coli Infections / epidemiology
  • Escherichia coli Infections / microbiology*
  • Genome, Bacterial / genetics
  • Humans
  • Immunoassay
  • Microbial Sensitivity Tests
  • Switzerland / epidemiology
  • beta-Lactamases / genetics
  • beta-Lactamases / immunology
  • beta-Lactamases / metabolism*
  • beta-Lactams / pharmacology

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • beta-Lactams
  • beta-Lactamases
  • carbapenemase