Integron-associated imipenem resistance in Acinetobacter baumannii isolated from a regional hospital in Taiwan

Int J Antimicrob Agents. 2006 Jan;27(1):81-4. doi: 10.1016/j.ijantimicag.2005.09.010. Epub 2005 Dec 15.

Abstract

We investigated the genetic properties of imipenem-resistant Acinetobacter baumannii collected from a regional hospital in Taiwan. Pulsed-field gel electrophoresis demonstrated that the isolates were genetically diverse. Polymerase chain reaction, DNA sequencing, and DNA-DNA hybridisation showed that the bla(IMP-1) gene resided as a cassette in a plasmid-borne class 1 integron in two isolates. The majority of the resistant isolates were plasmid-less and carried no bla(IMP), bla(VIM) or bla(CFI) genes, indicating that other uncharacterised metallo-beta-lactamases or mechanisms other than enzyme production are involved in carbapenem resistance in this group of A. baumannii. We conclude that multidrug resistance of A. baumannii was a combined effect of lateral gene transfer and clonal spread of multiple resistant clones. Strict measures should be implemented to control the further spread of resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter baumannii / drug effects
  • Acinetobacter baumannii / genetics*
  • Acinetobacter baumannii / physiology
  • Anti-Bacterial Agents / pharmacology*
  • Cross Infection / microbiology
  • Electrophoresis, Gel, Pulsed-Field
  • Gene Order
  • Humans
  • Imipenem / pharmacology*
  • Integrons*
  • Plasmids / genetics
  • Polymerase Chain Reaction
  • Taiwan
  • beta-Lactam Resistance / genetics*
  • beta-Lactamases / genetics

Substances

  • Anti-Bacterial Agents
  • Imipenem
  • VIM-2 beta-lactamase
  • beta-lactamase IMP-1
  • beta-Lactamases