Long-term Dissemination of an OXA-40 Carbapenemase-Producing Acinetobacter Baumannii Clone in the Iberian Peninsula

J Antimicrob Chemother. 2004 Jul;54(1):255-8. doi: 10.1093/jac/dkh269. Epub 2004 Jun 9.

Abstract

Objective: The main objectives of this study were to assess the clonal relatedness of Acinetobacter baumannii carbapenem-resistant isolates recovered from the Iberian Peninsula and to investigate the production of carbapenemases.

Methods: One hundred and sixty-two imipenem-resistant A. baumannii isolates were collected from 1998 to 2003 in three Portuguese university hospitals. An imipenem-resistant isolate (988FFP strain) recovered in 1995 from a smaller hospital unit, was also included, as well as an OXA-40-producing A. baumannii Spanish strain (SM28). Susceptibility tests were carried out by disc diffusion and Etest methods. DNA fingerprints were obtained by PFGE of ApaI-digested chromosomal DNA. Carbapenemase activity was determined by a bioassay and spectrophotometry. The detection of the blaOXA-40 gene was conducted through PCR analysis, cloning and nucleotide sequencing.

Results: All the isolates presented a similar multi-resistance pattern, including imipenem (MIC >32 mg/L). The Iberian isolates showed an identical PFGE pattern with minor band variations, including isolate 988FFP collected in 1995. PCR results revealed a blaOXA-type gene in 65 isolates and nucleotide sequence analysis revealed the presence of the blaOXA-40 gene in seven representative Portuguese isolates from the various geographically dispersed hospitals.

Conclusions: Our results indicate that a multi-resistant epidemic clone of A. baumannii, carrying blaOXA-40, is disseminated in the Iberian Peninsula, persisting in Portugal since 1995.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter Infections / epidemiology*
  • Acinetobacter Infections / microbiology*
  • Acinetobacter baumannii / drug effects
  • Acinetobacter baumannii / enzymology*
  • Acinetobacter baumannii / genetics
  • Bacterial Proteins / biosynthesis*
  • Bacterial Proteins / genetics
  • Chromosomes, Bacterial / genetics
  • Cross Infection / microbiology
  • DNA Fingerprinting
  • DNA, Bacterial / genetics
  • Drug Resistance, Bacterial
  • Electrophoresis, Gel, Pulsed-Field
  • Humans
  • Imipenem / pharmacology*
  • Microbial Sensitivity Tests
  • Portugal / epidemiology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Spain / epidemiology
  • beta-Lactamases / biosynthesis*
  • beta-Lactamases / genetics

Substances

  • Bacterial Proteins
  • DNA, Bacterial
  • Imipenem
  • beta-Lactamases
  • beta-lactamase OXA-40, Acinetobacter baumannii
  • carbapenemase