Human and swine hosts share vancomycin-resistant Enterococcus faecium CC17 and CC5 and Enterococcus faecalis CC2 clonal clusters harboring Tn1546 on indistinguishable plasmids

J Clin Microbiol. 2011 Mar;49(3):925-31. doi: 10.1128/JCM.01750-10. Epub 2011 Jan 12.

Abstract

VRE isolates from pigs (n = 29) and healthy persons (n = 12) recovered during wide surveillance studies performed in Portugal, Denmark, Spain, Switzerland, and the United States (1995 to 2008) were compared with outbreak/prevalent VRE clinical strains (n = 190; 23 countries; 1986 to 2009). Thirty clonally related Enterococcus faecium clonal complex 5 (CC5) isolates (17 sequence type 6 [ST6], 6 ST5, 5 ST185, 1 ST147, and 1 ST493) were obtained from feces of swine and healthy humans. This collection included isolates widespread among pigs of European Union (EU) countries since the mid-1990s. Each ST comprised isolates showing similar pulsed-field gel electrophoresis (PFGE) patterns (≤6 bands difference; >82% similarity). Some CC5 PFGE subtype strains from swine were indistinguishable from hospital vancomycin-resistant enterococci (VRE) causing infections. A truncated variant of Tn1546 (encoding resistance to vancomycin) and tcrB (coding for resistance to copper) were consistently located on 150- to 190-kb plasmids (rep(pLG1)). E. faecium CC17 (ST132) isolates from pig manure and two clinical samples showed identical PFGE profiles and contained a 60-kb mosaic plasmid (rep(Inc18) plus rep(pRUM)) carrying diverse Tn1546-IS1216 variants. The only Enterococcus faecalis isolate obtained from pigs (CC2-ST6) corresponded to a multidrug-resistant clone widely disseminated in hospitals in Italy, Portugal, and Spain, and both animal and human isolates harbored an indistinguishable 100-kb mosaic plasmid (rep(pRE25) plus rep(pCF10)) containing the whole Tn1546 backbone. The results indicate a current intra- and international spread of E. faecium and E. faecalis clones and their plasmids among swine and humans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Typing Techniques
  • Cluster Analysis
  • DNA Transposable Elements
  • DNA, Bacterial / genetics*
  • Enterococcus faecalis / classification*
  • Enterococcus faecalis / drug effects
  • Enterococcus faecalis / genetics
  • Enterococcus faecalis / isolation & purification
  • Enterococcus faecium / classification*
  • Enterococcus faecium / drug effects
  • Enterococcus faecium / genetics
  • Enterococcus faecium / isolation & purification
  • European Union
  • Genotype
  • Gram-Positive Bacterial Infections / microbiology*
  • Gram-Positive Bacterial Infections / veterinary*
  • Humans
  • Molecular Epidemiology
  • Molecular Typing
  • Plasmids
  • Swine
  • Swine Diseases / microbiology*
  • United States
  • Vancomycin Resistance*

Substances

  • DNA Transposable Elements
  • DNA, Bacterial