title: Detection and molecular characterisation of plasmidic AmpC beta-lactamases in Klebsiella pneumoniae isolates from a tertiary-care hospital in Dublin, Ireland.
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).
authors.affiliation: Department of Microbiology, Central Pathology Laboratory, St James's Hospital, and Department of Clinical Microbiology, University of Dublin, Trinity College, Dublin, Ireland.
authors.forename: C
authors.initials: C
authors.lastname: Roche
authors.forename: T W
authors.initials: TW
authors.lastname: Boo
authors.forename: F
authors.initials: F
authors.lastname: Walsh
authors.forename: B
authors.initials: B
authors.lastname: Crowley
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000032:analysis*; D018550:Cephalosporin Resistance; D002511:Cephalosporins / Q000494:pharmacology; D016000:Cluster Analysis; D003428:Cross Infection / Q000453:epidemiology; D016521:Electrophoresis, Gel, Pulsed-Field; D005798:Genes, Bacterial; D005838:Genotype; D007494:Ireland / Q000453:epidemiology; D007710:Klebsiella Infections / Q000453:epidemiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000032:analysis; D016133:Polymerase Chain Reaction; D015995:Prevalence; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002511:Cephalosporins; C048795:AmpC beta-lactamases; D001618:beta-Lactamases