Detection of vanA and vanB2-containing enterococci from food samples in Spain, including Enterococcus faecium strains of CC17 and the new singleton ST425

Int J Food Microbiol. 2009 Jul 31;133(1-2):172-8. doi: 10.1016/j.ijfoodmicro.2009.05.020. Epub 2009 May 23.

Abstract

Two-hundred-twenty-nine food samples of animal origin were tested to know the prevalence of vancomycin-resistant enterococci (VRE) after a decade of avoparcin ban as animal growth promoter in Spain. VRE with acquired mechanism of resistance were detected in 9 of these 229 samples (3.9%, obtained from chicken, veal and rabbit), and one VRE per food sample was further characterized. The vanA gene was identified in seven isolates (2 E. faecium, 3 E. durans, and 2 E. hirae), and the vanB2 gene in the remaining 2 isolates (identified as E. faecium). The two vanB2 isolates showed a phenotype of multiresistance that included, in addition to vancomycin, also ampicillin, erythromycin, tetracycline, streptomycin, kanamycin, ciprofloxacin, chloramphenicol and trimethoprim-sulfamethoxazole and contained, among others, erm(B), tet(M), ant(6), and aph(3')-III genes. Most of vanA enterococci showed erythromycin and tetracycline resistance and contained the erm(B) and tet(M) genes. One vanA- and both vanB2-positive E. faecium isolates were classified by MLST analysis into the CC17 clonal complex (ST17 and ST78), and one additional vanA isolate was included in a new sequence type named ST425 (singleton). Co-transference by conjugation of erm(B) and vanA genes was demonstrated in one vanA-positive E. faecium isolate. The inclusion of vanB2 cluster into Tn5382 structure was demonstrated in the two vanB2 isolates, as well as the linkage pbp5-Tn5382, and beta-haemolysis and gelatinase production was identified in one of them. Food sample of animal origin could be a vehicle of transference of VRE of vanA and vanB2 type that could be transferred to humans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents
  • Cattle
  • Chickens
  • Conjugation, Genetic
  • Drug Resistance, Bacterial / genetics
  • Drug Resistance, Multiple, Bacterial*
  • Drug and Narcotic Control
  • Enterococcus faecium / classification
  • Enterococcus faecium / genetics
  • Enterococcus faecium / isolation & purification*
  • Food Microbiology*
  • Gelatinases
  • Genes, Bacterial*
  • Genetic Variation
  • Glycopeptides
  • Humans
  • Rabbits
  • Spain
  • Vancomycin Resistance / genetics*
  • Virulence / genetics

Substances

  • Anti-Bacterial Agents
  • Glycopeptides
  • Gelatinases
  • avoparcin