Complete sequencing of the bla(NDM-1)-positive IncA/C plasmid from Escherichia coli ST38 isolate suggests a possible origin from plant pathogens

PLoS One. 2011;6(9):e25334. doi: 10.1371/journal.pone.0025334. Epub 2011 Sep 23.

Abstract

The complete sequence of the plasmid pNDM-1_Dok01 carrying New Delhi metallo-β-lactamase (NDM-1) was determined by whole genome shotgun sequencing using Escherichia coli strain NDM-1_Dok01 (multilocus sequence typing type: ST38) and the transconjugant E. coli DH10B. The plasmid is an IncA/C incompatibility type composed of 225 predicted coding sequences in 195.5 kb and partially shares a sequence with bla(CMY-2)-positive IncA/C plasmids such as E. coli AR060302 pAR060302 (166.5 kb) and Salmonella enterica serovar Newport pSN254 (176.4 kb). The bla(NDM-1) gene in pNDM-1_Dok01 is terminally flanked by two IS903 elements that are distinct from those of the other characterized NDM-1 plasmids, suggesting that the bla(NDM-1) gene has been broadly transposed, together with various mobile elements, as a cassette gene. The chaperonin groES and groEL genes were identified in the bla(NDM-1)-related composite transposon, and phylogenetic analysis and guanine-cytosine content (GC) percentage showed similarities to the homologs of plant pathogens such as Pseudoxanthomonas and Xanthomonas spp., implying that plant pathogens are the potential source of the bla(NDM-1) gene. The complete sequence of pNDM-1_Dok01 suggests that the bla(NDM-1) gene was acquired by a novel composite transposon on an extensively disseminated IncA/C plasmid and transferred to the E. coli ST38 isolate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Phylogeny
  • Plants / enzymology*
  • Plants / genetics
  • Plasmids / genetics*
  • beta-Lactamases / classification
  • beta-Lactamases / genetics*

Substances

  • beta-Lactamases
  • beta-lactamase NDM-1