title: Comparative study of vanA gene transfer from Enterococcus faecium to Enterococcus faecalis and to Enterococcus faecium in the intestine of mice.
abstract: Vancomycin-resistant enterococci represent a large reservoir in animals because of the use of avoparcin as a growth promoter in Europe. These strains of animal origin enter the food chain and can either colonize the human gut or transfer their resistance genes to the human microbiota. In this study, we compared the transfer of vancomycin resistance from resistant animal Enterococcus faecium to sensitive human Enterococcus faecalis and E. faecium. We analysed these transfers in dibiotic mice and human faecal flora-associated mice. VanA transfer from animal E. faecium to human E. faecalis occurred in dibiotic mice. The transconjugants appeared rapidly and persisted at levels between 3.0 and 4.0 log10 colony-forming units g(-1) of faeces. In human faecal flora-associated mice, vanA gene transfer was not detected towards E. faecalis but was possible between E. faecium strains. Our experiments revealed the possibility of vanA transfer from animal E. faecium to human E. faecalis in vitro and in vivo in the intestine of dibiotic mice. However, intraspecies transfer of vanA gene seems more common than interspecies transfer among enterococci.
authors.affiliation: Laboratoire de Microbiologie, UFR des Sciences Pharmaceutiques et Biologiques, Université René Descartes, Paris, France.
authors.forename: Nadège
authors.initials: N
authors.lastname: Bourgeois-Nicolaos
authors.forename: Carole
authors.initials: C
authors.lastname: Moubareck
authors.forename: Nicole
authors.initials: N
authors.lastname: Mangeney
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: Butel
authors.forename: Florence
authors.initials: F
authors.lastname: Doucet-Populaire
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D019729:Carbon-Oxygen Ligases / Q000235:genetics*; D003227:Conjugation, Genetic; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000235:genetics; D016984:Enterococcus faecium / Q000187:drug effects* / Q000235:genetics; D005243:Feces / Q000382:microbiology; D022761:Gene Transfer, Horizontal; D005856:Germ-Free Life; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D051379:Mice; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C071437:VanA ligase, Bacteria; D019729:Carbon-Oxygen Ligases