title: Characterization of the chromosomal class A beta-lactamase CKO from Citrobacter koseri.
abstract: The gene bla(CKO) encoding the chromosomal class A beta-lactamase of Citrobacter koseri was cloned and sequenced. CKO was found to display only 41% identity with SED-1 from Citrobacter sedlakii and 36% with CdiA from Citrobacter amalonaticus (formerly Citrobacter diversus). No transcriptional regulator was found upstream from bla(CKO). Silent and missense mutations were detected in four bla(CKO) genes amplified from different C. koseri clinical isolates, but the CKO variants displayed identical biochemical behaviours. A bla(CKO)-specific polymerase chain reaction confirmed that bla(CKO) is present only in C. koseri and therefore represents an interesting tool with which to differentiate C. koseri from the other Citrobacter spp.
authors.affiliation: Laboratoire de Recherche Moléculaire sur les Antibiotiques, Faculté de médecine Pitié-Salpêtrière, Université Pierre et Marie Curie, Paris, France.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Petrella
authors.forename: Murielle
authors.initials: M
authors.lastname: Renard
authors.forename: Nathalie
authors.initials: N
authors.lastname: Ziental-Gelus
authors.forename: Dominique
authors.initials: D
authors.lastname: Clermont
authors.forename: Vincent
authors.initials: V
authors.lastname: Jarlier
authors.forename: Wladimir
authors.initials: W
authors.lastname: Sougakoff
mesh_terms: D019943:Amino Acid Substitution; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002876:Chromosomes, Bacterial; D041041:Citrobacter koseri / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases