title: In vivo selection of oxacillinase-mediated ceftazidime resistance in Pseudomonas aeruginosa.
abstract: Ceftazidime-susceptible and -resistant Pseudomonas aeruginosa strains were isolated from pulmonary specimens following a treatment with ceftazidime in a patient who developed a nosocomial pneumonia. The ceftazidime-susceptible and -resistant strains were clonally related and harbored a self-transferable approximately 155-kb plasmid. These isolates expressed two OXA-10-like oxacillinases, the narrow-spectrum OXA-35 and the expanded-spectrum OXA-19, respectively, differing by one amino acid substitution. This is the first example of in vivo selection of an extended-spectrum oxacillinase from a restricted-spectrum oxacillinase.
authors.affiliation: Service de Bactériologie-Virologie, Hôpital de Bicêtre, Faculté de Médecine Paris-Sud, France.
authors.forename: S
authors.initials: S
authors.lastname: Leotard
authors.forename: L
authors.initials: L
authors.lastname: Poirel
authors.forename: P E
authors.initials: PE
authors.lastname: Leblanc
authors.forename: P
authors.initials: P
authors.lastname: Nordmann
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002352:Carrier Proteins / Q000235:genetics* / Q000494:pharmacology*; D002442:Ceftazidime / Q000494:pharmacology*; D018550:Cephalosporin Resistance / Q000235:genetics*; D002511:Cephalosporins / Q000494:pharmacology*; D003227:Conjugation, Genetic / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011552:Pseudomonas Infections / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D001618:beta-Lactamases / Q000235:genetics* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D002352:Carrier Proteins; D002511:Cephalosporins; D004269:DNA, Bacterial; D002442:Ceftazidime; D001618:beta-Lactamases; C108449:oxacillinase