title: The ACT-1 plasmid-encoded AmpC beta-lactamase is inducible: detection in a complex beta-lactamase background.
abstract: The purpose of this study was to identify the genetic organization and inducibility of bla(ACT-1) in a clinical isolate of Klebsiella pneumoniae possessing at least five different beta-lactamases. The genetic organization of the bla(ACT-1)/ampR region is identical to those of inducible chromosomal ampC genes. RNA analysis using primer extension demonstrated a five-fold increase in bla(ACT-1) transcript production on exposure to cefoxitin. These findings are significant because induction was detected in a complicated beta-lactamase background. In addition, this report is the first to describe an inducible plasmid-encoded AmpC beta-lactamase of Enterobacter cloacae origin.
authors.affiliation: Department of Medical Microbiology and Immunology, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Reisbig
authors.forename: Nancy D
authors.initials: ND
authors.lastname: Hanson
mesh_terms: D001426:Bacterial Proteins; D002440:Cefoxitin / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000032:analysis; D004790:Enzyme Induction; D005798:Genes, Bacterial; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D010957:Plasmids; D016133:Polymerase Chain Reaction; D012329:RNA, Bacterial / Q000032:analysis; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012329:RNA, Bacterial; D002440:Cefoxitin; C048795:AmpC beta-lactamases; D001618:beta-Lactamases