title: In vivo transfer of the vanA resistance gene from an Enterococcus faecium isolate of animal origin to an E. faecium isolate of human origin in the intestines of human volunteers.
abstract: Transient colonization by vancomycin-resistant enterococci of animal origin has been documented in the intestines of humans. However, little is known about whether transfer of the vanA gene occurs in the human intestine. Six volunteers ingested a vancomycin-resistant Enterococcus faecium isolate of chicken origin, together with a vancomycin-susceptible E. faecium recipient of human origin. Transconjugants were recovered in three of six volunteers. In one volunteer, not only was vancomycin resistance transferred, but also quinupristin-dalfopristin resistance. This study shows that transfer of the vanA gene from an E. faecium isolate of animal origin to an E. faecium isolate of human origin can occur in the intestines of humans. It suggests that transient intestinal colonization by enterococci carrying mobile elements with resistance genes represents a risk for spread of resistance genes to other enterococci that are part of the human indigenous flora, which can be responsible for infections in certain groups of patients, e.g., immunocompromised patients.
authors.affiliation: National Center for Antimicrobials and Infection Control, Statens Serum Institut, 5 Artillerivej, DK-2300 Copenhagen S, Denmark. cal@ssi.dk
authors.forename: Camilla H
authors.initials: CH
authors.lastname: Lester
authors.forename: Niels
authors.initials: N
authors.lastname: Frimodt-Møller
authors.forename: Thomas Lund
authors.initials: TL
authors.lastname: Sørensen
authors.forename: Dominique L
authors.initials: DL
authors.lastname: Monnet
authors.forename: Anette M
authors.initials: AM
authors.lastname: Hammerum
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D019729:Carbon-Oxygen Ligases / Q000235:genetics*; D002645:Chickens; D003227:Conjugation, Genetic; D004251:DNA Transposable Elements; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D020713:Vancomycin Resistance / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; C071437:VanA ligase, Bacteria; D019729:Carbon-Oxygen Ligases