title: The Balkan region: NDM-1-producing Klebsiella pneumoniae ST11 clonal strain causing outbreaks in Greece.
abstract: OBJECTIVE
  Despite the fact that the NDM-1 carbapenemase has successfully disseminated worldwide, outbreaks remain uncommon in the European region. We describe the characteristics of the first outbreaks caused by NDM-1-producing Klebsiella pneumoniae clonal isolates in Greece.
  
  
  METHODS
  Between January 2010 and June 2013, 132 non-repetitive carbapenem-resistant Enterobacteriaceae isolates, which gave a positive modified Hodge test and were phenotypically suspected of metallo-β-lactamase production, were recovered from patients hospitalized at Ioannina University Hospital. Resistance genes were identified by PCR and sequencing. Plasmid profiling, conjugation experiments, enterobacterial repetitive intergenic consensus PCR, PFGE and multilocus sequence typing (MLST) were performed. Patient records were retrieved to access patterns of acquisition.
  
  
  RESULTS
  Molecular testing verified the presence in 78 K. pneumoniae isolates, collected from 71 patients, of the blaNDM-1 gene. The blaCTX-M-15, blaOXA-1 and blaTEM-1 genes were also present in most isolates. The blaNDM-1 gene was located on a narrow host range IncFII-type plasmid, of ∼95 kb, flanked upstream by a non-truncated ISAba125 element and downstream by the bleMBL gene. Genotyping clustered all K. pneumoniae isolates into a single clonal type with one subtype and MLST assigned them to sequence type 11. Two outbreaks were noted, the first between November and December 2011 involving four patients and the second initiated in May 2012 and ongoing, involving the remaining patients. All but two cases were characterized as hospital acquired. No links to immigration or travel history to endemic areas were established.
  
  
  CONCLUSIONS
  This survey highlights the successful undetected dissemination of yet another carbapenemase in Greece and strengthens the hypothesis of a latent NDM-1 cluster in the Balkan region.
authors.affiliation: Department of Microbiology, Medical School, University of Athens, Athens, Greece.
authors.forename: Evangelia
authors.initials: E
authors.lastname: Voulgari
authors.affiliation: Department of Microbiology, Medical School, Ioannina University Hospital, Ioannina, Greece.
authors.forename: Constantina
authors.initials: C
authors.lastname: Gartzonika
authors.affiliation: Department of Microbiology, Medical School, University of Athens, Athens, Greece.
authors.forename: Georgia
authors.initials: G
authors.lastname: Vrioni
authors.affiliation: Department of Microbiology, Medical School, University of Athens, Athens, Greece.
authors.forename: Lida
authors.initials: L
authors.lastname: Politi
authors.affiliation: Department of Microbiology, Medical School, Ioannina University Hospital, Ioannina, Greece.
authors.forename: Efthalia
authors.initials: E
authors.lastname: Priavali
authors.affiliation: Department of Microbiology, Medical School, Ioannina University Hospital, Ioannina, Greece.
authors.forename: Stamatina
authors.initials: S
authors.lastname: Levidiotou-Stefanou
authors.affiliation: Department of Microbiology, Medical School, University of Athens, Athens, Greece atsakris@med.uoa.gr.
authors.forename: Athanassios
authors.initials: A
authors.lastname: Tsakris
mesh_terms: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins / Q000235:genetics*; D015373:Bacterial Typing Techniques; D001483:Base Sequence; D015780:Carbapenems / Q000494:pharmacology; D003428:Cross Infection / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D004196:Disease Outbreaks; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005260:Female; D005838:Genotype; D006115:Greece / Q000453:epidemiology; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D008297:Male; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D010957:Plasmids / Q000235:genetics; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015780:Carbapenems; D004269:DNA, Bacterial; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1; C063912:carbapenemase
keywords: K. pneumoniae; carbapenemases; sequence types