title: Molecular characterization of Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae in Ontario, Canada, 2008-2011.
abstract: Due to the lack of detailed reports of Klebsiella pneumoniae carbapenemase (KPC)-producing enterobacteria in Ontario, Canada, we perform a molecular characterization of KPC-producing Enterobacteriaceae submitted to the provincial reference laboratory from 2008 to 2011. Susceptibility profiles were accessed by E-test. Molecular types of isolates were determined by pulse-field gel electrophoresis (PFGE) and multilocus sequence typing. Screening of ß-lactamase genes was performed by multiplex PCR and alleles were identified by DNA sequencing. The genetic platform of blaKPC gene was analyzed by PCR. Plasmid replicons were typed using PCR-based typing approach. KPC-plasmids were also evaluated by S1 nuclease-PFGE and Southern blot. Thirty unique clinical isolates (26 Klebsiella pneumoniae, 2 Enterobacter cloacae, 1 Citrobacter freundii and 1 Raoultella ornithinolytica) were identified as blaKPC positive: 4 in 2008, 3 in 2009, 10 in 2010 and 13 in 2011. The majority exhibited resistance to carbapenems, cephalosporins and fluoroquinolones and two isolates were also resistant to colistin. The isolates harbored blaKPC-2 (n = 23) or blaKPC-3 (n = 7). blaTEM-1 (n = 27) was commonly detected and occasionally blaOXA-1 (n = 3) and blaCTX-M-15 (n = 1). As expected, all K. pneumoniae isolates carried blaSHV-11. blaKPC genes were identified on Tn4401a (n = 20) or b (n = 10) isoforms, on plasmids of different sizes belonging to the incompatibility groups IncFIIA (n = 19), IncN (n = 3), IncI2 (n = 3), IncFrep (n = 2) and IncA/C (n = 1). The occurrence of KPC ß-lactamase in Ontario was mainly associated with the spread of the K. pneumoniae clone ST258.
authors.affiliation: Public Health Ontario Laboratories, Toronto, Ontario, Canada.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Tijet
authors.affiliation: Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada.
authors.forename: Prameet M
authors.initials: PM
authors.lastname: Sheth
authors.affiliation: Public Health Ontario Laboratories, Toronto, Ontario, Canada.
authors.forename: Olga
authors.initials: O
authors.lastname: Lastovetska
authors.affiliation: Public Health Ontario Laboratories, Toronto, Ontario, Canada.
authors.forename: Catherine
authors.initials: C
authors.lastname: Chung
authors.affiliation: Public Health Ontario Laboratories, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Samir N
authors.initials: SN
authors.lastname: Patel
authors.affiliation: Public Health Ontario Laboratories, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada; Department of Microbiology, Mt Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Roberto G
authors.initials: RG
authors.lastname: Melano
mesh_terms: D000368:Aged; D001426:Bacterial Proteins / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology* / Q000652:urine; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification*; D008297:Male; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D009864:Ontario; D010957:Plasmids / Q000235:genetics; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D001618:beta-Lactamases; C063912:carbapenemase