Comparative analysis of the first complete Enterococcus faecium genome

J Bacteriol. 2012 May;194(9):2334-41. doi: 10.1128/JB.00259-12. Epub 2012 Feb 24.

Abstract

Vancomycin-resistant enterococci (VRE) are one of the leading causes of nosocomial infections in health care facilities around the globe. In particular, infections caused by vancomycin-resistant Enterococcus faecium are becoming increasingly common. Comparative and functional genomic studies of E. faecium isolates have so far been limited owing to the lack of a fully assembled E. faecium genome sequence. Here we address this issue and report the complete 3.0-Mb genome sequence of the multilocus sequence type 17 vancomycin-resistant Enterococcus faecium strain Aus0004, isolated from the bloodstream of a patient in Melbourne, Australia, in 1998. The genome comprises a 2.9-Mb circular chromosome and three circular plasmids. The chromosome harbors putative E. faecium virulence factors such as enterococcal surface protein, hemolysin, and collagen-binding adhesin. Aus0004 has a very large accessory genome (38%) that includes three prophage and two genomic islands absent among 22 other E. faecium genomes. One of the prophage was present as inverted 50-kb repeats that appear to have facilitated a 683-kb chromosomal inversion across the replication terminus, resulting in a striking replichore imbalance. Other distinctive features include 76 insertion sequence elements and a single chromosomal copy of Tn1549 containing the vanB vancomycin resistance element. A complete E. faecium genome will be a useful resource to assist our understanding of this emerging nosocomial pathogen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosomes, Bacterial
  • Enterococcus faecium / drug effects
  • Enterococcus faecium / genetics*
  • Enterococcus faecium / metabolism*
  • Enterococcus faecium / pathogenicity
  • Gene Expression Regulation, Bacterial / physiology
  • Genome, Bacterial / genetics*
  • Molecular Sequence Data
  • Phylogeny
  • Plasmids
  • Prophages / genetics
  • Vancomycin / pharmacology
  • Vancomycin Resistance
  • Virulence

Substances

  • Vancomycin

Associated data

  • GENBANK/CP003351
  • GENBANK/CP003352
  • GENBANK/CP003353
  • GENBANK/CP003354