Detection and molecular characterisation of plasmidic AmpC beta-lactamases in Klebsiella pneumoniae isolates from a tertiary-care hospital in Dublin, Ireland

Clin Microbiol Infect. 2008 Jun;14(6):616-8. doi: 10.1111/j.1469-0691.2008.01998.x. Epub 2008 Apr 5.

Abstract

This study determined the types of AmpC enzymes produced by Klebsiella pneumoniae isolates resistant to third-generation cephalosporins and the clonality of these isolates. The presence of AmpC enzymes was identified by cephalosporin-cloxacillin synergy tests. Genes encoding AmpC enzymes were characterised by PCR and sequencing. Pulsed-field gel electrophoresis (PFGE) was used to type the isolates. Fifteen K. pneumoniae isolates were positive for bla(AmpC), 13 were positive for bla(ACC-1) and two were positive for bla(DHA-1). Production of the DHA-1 enzyme was inducible. The ampR gene was identified upstream of the bla(DHA-1) gene. PFGE demonstrated the polyclonal origin of the isolates carrying bla(ACC-1).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / analysis*
  • Cephalosporin Resistance
  • Cephalosporins / pharmacology
  • Cluster Analysis
  • Cross Infection / epidemiology
  • Electrophoresis, Gel, Pulsed-Field
  • Genes, Bacterial
  • Genotype
  • Ireland / epidemiology
  • Klebsiella Infections / epidemiology*
  • Klebsiella pneumoniae / drug effects
  • Klebsiella pneumoniae / enzymology*
  • Klebsiella pneumoniae / genetics*
  • Microbial Sensitivity Tests
  • Plasmids / analysis
  • Polymerase Chain Reaction
  • Prevalence
  • Sequence Analysis, DNA
  • beta-Lactamases / analysis*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Cephalosporins
  • AmpC beta-lactamases
  • beta-Lactamases