title: Increased conjugation frequencies in clinical Enterococcus faecium strains harbouring the enterococcal surface protein gene esp.
abstract: This study compared the in-vitro ability of Enterococcus faecium isolates of different origin to acquire vanA by conjugation in relation to the occurrence of the esp gene. In total, 29 clinical isolates (15/29 esp+), 30 normal intestinal microflora isolates (2/30 esp+) and one probiotic strain (esp-) were studied with a filter-mating assay. Conjugation events were confirmed by PCR and pulsed-field gel electrophoresis. Among the infection-derived isolates, the esp+ isolates had higher conjugation frequencies compared with esp- isolates (p < 0.001), with a median value of 6.4 x 10(-6) transconjugants/donor. The probiotic strain was shown to acquire vanA vancomycin resistance in in-vitro filter mating experiments.
authors.affiliation: Division of Clinical Bacteriology, Department of Laboratory Medicine, Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Lund
authors.forename: H
authors.initials: H
authors.lastname: Billström
authors.forename: C
authors.initials: C
authors.lastname: Edlund
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology*; D019729:Carbon-Oxygen Ligases / Q000235:genetics / Q000502:physiology*; D003227:Conjugation, Genetic / Q000235:genetics / Q000502:physiology*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D016984:Enterococcus faecium / Q000235:genetics* / Q000302:isolation & purification*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000502:physiology; D016133:Polymerase Chain Reaction / Q000379:methods
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; C071437:VanA ligase, Bacteria; C116707:enterococcal surface protein, esp; D019729:Carbon-Oxygen Ligases