Multicopy blaOXA-58 gene as a source of high-level resistance to carbapenems in Acinetobacter baumannii

Antimicrob Agents Chemother. 2007 Jul;51(7):2324-8. doi: 10.1128/AAC.01502-06. Epub 2007 Apr 16.

Abstract

The mechanisms at the origin of heterogeneous carbapenem resistance levels observed among Acinetobacter baumannii isolates collected in 2005 in a large University Hospital of Rome, Italy, were investigated. These isolates were related and possessed similar plasmids carrying the carbapenem-hydrolyzing oxacillinase gene bla(OXA-58) but showed variable levels of resistance to carbapenems. Analysis of sequences surrounding the bla(OXA-58) gene showed genetic variability, with the presence in several isolates of multiple copies of the bla(OXA-58) gene; this extra copy number was likely related to an IS26-mediated transposition or recombination process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter baumannii / drug effects*
  • Acinetobacter baumannii / enzymology
  • Acinetobacter baumannii / genetics*
  • Acinetobacter baumannii / isolation & purification
  • Anti-Bacterial Agents / pharmacology*
  • Base Sequence
  • Carbapenems / pharmacology*
  • Cloning, Molecular
  • DNA, Bacterial / analysis
  • DNA, Bacterial / genetics
  • Gene Dosage*
  • Genes, Bacterial*
  • Genetic Variation
  • Humans
  • Microbial Sensitivity Tests
  • Nucleic Acid Amplification Techniques
  • Plasmids
  • Polymerase Chain Reaction
  • Sequence Analysis, DNA
  • beta-Lactam Resistance*
  • beta-Lactamases / biosynthesis
  • beta-Lactamases / genetics

Substances

  • Anti-Bacterial Agents
  • Carbapenems
  • DNA, Bacterial
  • beta-Lactamases
  • oxacillinase