title: Complete sequencing of an IncH plasmid carrying the blaNDM-1, blaCTX-M-15 and qnrB1 genes.
abstract: OBJECTIVE
  To characterize plasmid pNDM-MAR recovered from a Klebsiella pneumoniae isolate of sequence type (ST) 15 from Morocco, carrying the genes encoding the metallo-β-lactamase NDM-1, the extended-spectrum β-lactamase (ESBL) CTX-M-15 and the qnrB1 quinolone resistance determinant.
  
  
  METHODS
  The plasmid DNA sequence was obtained by using the 454-Genome Sequencer FLX procedure on a library constructed from total plasmid DNA obtained from an Escherichia coli J53 transconjugant. Contig assembly and predicted gaps were confirmed and filled by PCR-based gap closure.
  
  
  RESULTS
  Plasmid pNDM-MAR was 267 242 bp long and encoded 177 predicted proteins. It harboured novel replicons and transfer loci, defining a novel plasmid type within the IncH plasmid family. The bla(NDM-1) gene was flanked by genetic elements that are distinct from those observed in other bla(NDM-1)-positive plasmids, including the groES and groEL chaperonin genes. This plasmid harboured the ESBL gene bla(CTX-M-15) together with the quinolone resistance gene qnrB1. In addition, it harboured genes encoding resistance to tellurite, mercury, chloramphenicol and aminoglycosides. Interestingly, pNDM-MAR did not carry any 16S rRNA methylase gene, in contrast to other bla(NDM-1)-positive plasmids.
  
  
  CONCLUSIONS
  This study underlines the diversity of genetic vehicles involved in the spread of the bla(NDM-1) gene. Plasmid pNDM-MAR differed significantly from all known bla(NDM-1)-bearing plasmids. Comparative analysis of the pNDM-MAR sequence identified a novel type of IncH plasmid.
authors.affiliation: Department of Infectious,  Parasitic and Immuno-Mediated Diseases, Istituto Superiore di Sanità, Rome,  Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Villa
authors.forename: Laurent
authors.initials: L
authors.lastname: Poirel
authors.forename: Patrice
authors.initials: P
authors.lastname: Nordmann
authors.forename: Claudio
authors.initials: C
authors.lastname: Carta
authors.forename: Alessandra
authors.initials: A
authors.lastname: Carattoli
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000737:chemistry* / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000235:genetics*; D008969:Molecular Sequence Data; D009018:Morocco; D010957:Plasmids; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; C485385:Qnr protein, Klebsiella pneumoniae; C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases; C552864:beta-lactamase NDM-1