The role of ISAba1 in expression of OXA carbapenemase genes in Acinetobacter baumannii

FEMS Microbiol Lett. 2006 May;258(1):72-7. doi: 10.1111/j.1574-6968.2006.00195.x.


ISAba1 was found in all widespread clones of Acinetobacter baumannii in the United Kingdom. All isolates studied had a blaOXA-51-like carbapenemase gene; some also had blaOXA-23-like and/or blaOXA-58-like. Among isolates with blaOXA-51-like as sole carbapenemase gene, only those with ISAba1 adjacent to blaOXA-51-like were carbapenem resistant. Minor differences in blaOXA-51-like sequence were observed in resistant and susceptible isolates. Isolates with blaOXA-23-like in addition were consistently resistant to carbapenems; in all of these ISAba1 lay upstream of blaOXA-23-like, but was not associated with blaOXA-51-like. These results suggest that ISAba1 is providing the promoter for blaOXA-51-like and, probably, for blaOXA-23-like.

MeSH terms

  • Acinetobacter baumannii / enzymology
  • Acinetobacter baumannii / genetics*
  • Bacterial Proteins / genetics*
  • DNA Transposable Elements / physiology*
  • Polymerase Chain Reaction
  • beta-Lactamases / genetics*


  • Bacterial Proteins
  • DNA Transposable Elements
  • beta-lactamase OXA-23
  • beta-Lactamases
  • carbapenemase