title: OXA-60, a chromosomal, inducible, and imipenem-hydrolyzing class D beta-lactamase from Ralstonia pickettii.
abstract: A chromosomally encoded oxacillinase, OXA-22, had been characterized from Ralstonia pickettii PIC-1 that did not explain by itself the resistance profile of this strain to beta-lactams. Thus, further analysis of the genetic background of this species led to the identification of another oxacillinase, OXA-60, that was expressed only after beta-lactam induction. This chromosomally encoded oxacillinase shared 19% amino acid identity with OXA-22. It has a narrow-spectrum hydrolysis profile that includes imipenem. OXA-60-like enzymes were identified in several R. pickettii strains. Gene inactivation and induction studies of the bla(OXA-60) and bla(OXA-22) genes in R. pickettii identified the relative contribution of each oxacillinase to the resistance profile of R. pickettii to beta-lactams.
authors.affiliation: Service de Bactériologie-Virologie, Hôpital de Bicêtre, 78 rue du Général Leclerc, 94275 Le Kremlin-Bicêtre Cédex, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Girlich
authors.forename: Thierry
authors.initials: T
authors.lastname: Naas
authors.forename: Patrice
authors.initials: P
authors.lastname: Nordmann
mesh_terms: D015139:Blotting, Southern; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial / Q000201:enzymology* / Q000235:genetics*; D003001:Cloning, Molecular; D003227:Conjugation, Genetic / Q000235:genetics; D004269:DNA, Bacterial / Q000096:biosynthesis / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D004790:Enzyme Induction / Q000187:drug effects; D006868:Hydrolysis; D015378:Imipenem / Q000378:metabolism*; D007525:Isoelectric Focusing; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D043367:Ralstonia / Q000201:enzymology* / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013845:Thienamycins / Q000378:metabolism*; D014158:Transcription, Genetic; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D013845:Thienamycins; D015378:Imipenem; D001618:beta-Lactamases; C494141:beta-lactamase OXA-60, Ralstonia pickettii