title: Characterization of a novel AmpC β-lactamase produced by a carbapenem-resistant Cedecea davisae clinical isolate.
abstract: A Cedecea davisae isolate, which was intermediate or resistant to third-generation cephalosporins and carbapenems, was recovered from a urine sample. Susceptibility testing, isoelectric focusing, and analysis of outer membrane proteins showed that AmpC β-lactamase expression combined with porin deficiency accounted for the carbapenem resistance. A cloning experiment followed by phenotypic and enzymatic characterization identified a novel class C enzyme that was phylogenetically and biochemically close to the chromosome-borne β-lactamases of the genera Enterobacter and Citrobacter.
authors.affiliation: Service de Réanimation Polyvalente, Centre Hospitalo-Universitaire d'Amiens, Hôpital Nord, Université de Picardie Jules Verne, Amiens, France INSERM U1088, Université de Picardie Jules Verne, Amiens, France.
authors.forename: Nacim
authors.initials: N
authors.lastname: Ammenouche
authors.affiliation: Service de Réanimation Polyvalente, Centre Hospitalo-Universitaire d'Amiens, Hôpital Nord, Université de Picardie Jules Verne, Amiens, France INSERM U1088, Université de Picardie Jules Verne, Amiens, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Dupont
authors.affiliation: Service de Bactériologie, Centre Hospitalo-Universitaire d'Amiens, Hôpital Nord, Faculté de Médecine d'Amiens, Université de Picardie Jules Verne, Amiens, France INSERM, IAME, UMR 1137, Paris, France hedi.mammeri@wanadoo.fr.
authors.forename: Hedi
authors.initials: H
authors.lastname: Mammeri
mesh_terms: D000368:Aged; D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D015780:Carbapenems / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D005260:Female; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010802:Phylogeny; D018272:Porins / Q000235:genetics; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D015780:Carbapenems; D018272:Porins; C048795:AmpC beta-lactamases; D001618:beta-Lactamases; C063912:carbapenemase