title: Emergence of clonally related Klebsiella pneumoniae isolates of sequence type 258 producing plasmid-mediated KPC carbapenemase in Norway and Sweden.
abstract: BACKGROUND
  The class A carbapenemase KPC has disseminated rapidly worldwide, challenging the treatment of Gram-negative infections. This report describes the first KPC-producing Klebsiella pneumoniae isolates identified in Norway (n=6) and the second isolate from Sweden.
  
  
  METHODS
  Antimicrobial susceptibility profiles were determined using Etest. PCR and sequencing were used to determine the bla(KPC) variant, the surrounding genetic structure and the presence of AmpC and extended-spectrum beta-lactamase genes. PFGE and multilocus sequence typing (MLST) were used for epidemiological comparisons. Localization of bla(KPC) was investigated by S1 nuclease digestion, followed by PFGE and Southern blot hybridization.
  
  
  RESULTS
  All isolates expressed a multidrug-resistant phenotype with some variability in the carbapenem susceptibility profile. The Norwegian isolates carried bla(KPC-2), while the Swedish isolate carried bla(KPC-3). All isolates carried TEM-1, but were negative for bla(CTX-M) and bla(AmpC) genes. SHV-11 and SHV-12 were detected in the Norwegian isolates, while the Swedish isolate carried only SHV-11. Isolates from four patients were associated with import from Greece (n=3) and Israel. The other isolates were probably associated with local transmissions. PFGE and MLST showed that the isolates were clonally related, with three isolates displaying ST258, a single locus variant of ST11 previously associated with the clonal spread of CTX-M-15-producing K. pneumoniae in Hungary. In all isolates, bla(KPC) was located on plasmids as part of isoform a of Tn4401.
  
  
  CONCLUSIONS
  The emergence of KPC-producing isolates of K. pneumoniae in Norway and Sweden is associated with multiple import events and probable local transmission of a successful multiresistant ST258 clone, closely related to the CTX-M-15-producing ST11 clone previously described in Hungary.
authors.affiliation: Reference Centre for Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway. orjan.samuelsen@unn.no
authors.forename: Ørjan
authors.initials: Ø
authors.lastname: Samuelsen
authors.forename: Umaer
authors.initials: U
authors.lastname: Naseer
authors.forename: Ståle
authors.initials: S
authors.lastname: Tofteland
authors.forename: Dag Harald
authors.initials: DH
authors.lastname: Skutlaberg
authors.forename: Annette
authors.initials: A
authors.lastname: Onken
authors.forename: Reidar
authors.initials: R
authors.lastname: Hjetland
authors.forename: Arnfinn
authors.initials: A
authors.lastname: Sundsfjord
authors.forename: Christian G
authors.initials: CG
authors.lastname: Giske
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D015139:Blotting, Southern; D015780:Carbapenems / Q000494:pharmacology*; D016172:DNA Fingerprinting; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D009664:Norway; D010957:Plasmids; D017422:Sequence Analysis, DNA; D013548:Sweden; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015780:Carbapenems; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D001618:beta-Lactamases; C063912:carbapenemase