title: Molecular analysis of NDM-1-producing enterobacterial isolates from Geneva, Switzerland.
abstract: OBJECTIVE
  To analyse the mechanisms responsible for decreased susceptibility or resistance to carbapenems in several enterobacterial isolates recovered in 2009-10 in Geneva University Hospitals, Switzerland.
  
  
  METHODS
  PCR and sequencing were used to identify β-lactamases, 16S RNA methylases and plasmid-mediated quinolone resistance genes. The transferable properties of the plasmids were analysed, as well as their plasmid type. The strains were typed by multilocus sequence typing.
  
  
  RESULTS
  Three patients were found to be positive for NDM-1-producing enterobacterial isolates (one with Escherichia coli and Klebsiella pneumoniae, one with K. pneumoniae only and one with Proteus mirabilis), where NDM-1 stands for New Delhi metallo-β-lactamase-1. The bla(NDM-1) carbapenemase gene was detected in all isolates in addition to genes encoding narrow-spectrum β-lactamases (TEM-1, SHV-11, OXA-1, OXA-9 and OXA-10), extended-spectrum β-lactamases (CTX-M-15, CMY-16 and CMY-30), ArmA and quinolone resistance determinants (Qnr). The bla(NDM-1) gene was located on conjugative IncA/C- or IncF-type plasmids. Upstream of the bla(NDM-1) gene, part of ISAba125, previously identified in NDM-1-negative Acinetobacter baumannii, was found. Downstream of the bla(NDM-1) gene, variable sequences were found.
  
  
  CONCLUSIONS
  This work constitutes the first identification of NDM-1 producers in Switzerland. Interestingly, patients from whom these NDM-1-producing isolates were recovered had a link with the Indian subcontinent or the Balkans.
authors.affiliation: Service de Bactériologie-Virologie, INSERM U914 Emerging Resistance to Antibiotics, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, Faculté de Médecine et Université Paris-Sud, K.-Bicêtre, Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Poirel
authors.forename: Jacques
authors.initials: J
authors.lastname: Schrenzel
authors.forename: Abdessalam
authors.initials: A
authors.lastname: Cherkaoui
authors.forename: Sandrine
authors.initials: S
authors.lastname: Bernabeu
authors.forename: Gesuele
authors.initials: G
authors.lastname: Renzi
authors.forename: Patrice
authors.initials: P
authors.lastname: Nordmann
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015780:Carbapenems / Q000494:pharmacology; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004755:Enterobacteriaceae / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology*; D022761:Gene Transfer, Horizontal; D006785:Hospitals, University; D006801:Humans; D058885:Multilocus Sequence Typing; D010957:Plasmids / Q000032:analysis; D016133:Polymerase Chain Reaction; D015363:Quinolones / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D013557:Switzerland / Q000453:epidemiology; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000235:genetics*; D012359:tRNA Methyltransferases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D004269:DNA, Bacterial; D015363:Quinolones; D012359:tRNA Methyltransferases; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1