title: Biochemical and genetic characterization of carbapenem-hydrolyzing β-lactamase OXA-229 from Acinetobacter bereziniae.
abstract: Acinetobacter bereziniae (formerly Acinetobacter genomospecies 10) isolate Nec was recovered from a skin sample of a patient hospitalized in Paris, France. It was resistant to penicillins, penicillin-inhibitor combinations, and carbapenems. Cloning and expression in Escherichia coli identified the carbapenem-hydrolyzing class D β-lactamase OXA-229, which is weakly related to other oxacillinases (66% amino acid identity with the closest oxacillinase, OXA-58). It hydrolyzed penicillins, oxacillin, and imipenem but not expanded-spectrum cephalosporins. Sequencing of the genetic context of the bla(OXA-229) gene did not identify an insertion sequence but did identify mutations in the promoter sequences in comparison to the fully susceptible A. bereziniae reference strain. The overexpression of bla(OXA-229) in A. bereziniae Nec as a source of carbapenem resistance was identified by quantitative real-time PCR.
authors.affiliation: Service de Bactériologie-Virologie, INSERM U914 Emerging Resistance to Antibiotics, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, Faculté de Médecine et Université Paris-Sud, K.-Bicêtre, Paris,France.
authors.forename: Rémy A
authors.initials: RA
authors.lastname: Bonnin
authors.forename: Alain A
authors.initials: AA
authors.lastname: Ocampo-Sosa
authors.forename: Laurent
authors.initials: L
authors.lastname: Poirel
authors.forename: Hélène
authors.initials: H
authors.lastname: Guet-Revillet
authors.forename: Patrice
authors.initials: P
authors.lastname: Nordmann
mesh_terms: D000150:Acinetobacter / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D015780:Carbapenems / Q000378:metabolism*; D007612:Kanamycin / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D013982:Ticarcillin / Q000494:pharmacology; D024363:Transcription Initiation Site; D001618:beta-Lactamases / Q000145:classification / Q000235:genetics / Q000378:metabolism*
chemical_list: D015780:Carbapenems; D007612:Kanamycin; D001618:beta-Lactamases; D013982:Ticarcillin