title: Characterisation of the CTX-M-15-encoding gene in Klebsiella pneumoniae strains from the Barcelona metropolitan area: plasmid diversity and chromosomal integration.
abstract: The localisation and genetic organisation of bla(CTX-M-15) were studied in 37 CTX-M-15-producing Klebsiella pneumoniae isolates collected from 2005 to 2008 within the Barcelona metropolitan area. Polymerase chain reaction (PCR)-based replicon typing and Southern hybridisations were used to identify the bla(CTX-M-15) location. The genetic environment was analysed by PCR mapping and sequencing, and transferability of bla(CTX-M-15) was evaluated by conjugation and transformation assays. The majority of the 37 isolates carried bla(CTX-M-15) in a plasmid location, frequently associated with the aac(6')-Ib-cr gene. Plasmids encoding bla(CTX-M-15) carried three distinct replicons, i.e. IncFII, IncR and IncFIIk, the latter two not having been described previously in association with bla(CTX-M-15). Several of these plasmids were not self-transferable. Furthermore, in all isolates belonging to sequence type ST-1, bla(CTX-M-15) was found integrated into the K. pneumoniae chromosome. In all the studied isolates, the mobile element ISEcp1 was found upstream of bla(CTX-M-15), whereas IS26 was found inserted within ISEcp1 in several isolates, in previously unreported positions. In conclusion, these findings indicate that among K. pneumoniae strains isolated in the Barcelona metropolitan area, bla(CTX-M-15) is associated with diverse genetic elements, including the IncR and IncFIIk replicons, as reported for the first time here, and the chromosome.
authors.affiliation: Servicio de Microbiología, Hospital Vall d'Hebron, 08035 Barcelona, Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: Coelho
authors.forename: Juan José
authors.initials: JJ
authors.lastname: González-López
authors.forename: Elisenda
authors.initials: E
authors.lastname: Miró
authors.forename: Carles
authors.initials: C
authors.lastname: Alonso-Tarrés
authors.forename: Beatriz
authors.initials: B
authors.lastname: Mirelis
authors.forename: María Nieves
authors.initials: MN
authors.lastname: Larrosa
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Bartolomé
authors.forename: Antonia
authors.initials: A
authors.lastname: Andreu
authors.forename: Ferran
authors.initials: F
authors.lastname: Navarro
authors.forename: James R
authors.initials: JR
authors.lastname: Johnson
authors.forename: Guillem
authors.initials: G
authors.lastname: Prats
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D015139:Blotting, Southern; D002876:Chromosomes, Bacterial; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D023061:Gene Order; D005798:Genes, Bacterial; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D013030:Spain; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases