title: Impact of elements containing glycopeptide resistance genes on expression of virulence in Enterococcus faecalis peritonitis: a pilot study with rats.
abstract: The relationship between virulence and chromosomal elements containing glycopeptide resistance genes was experimentally assessed for two transconjugant strains of Enterococcus faecalis (VanA and VanB phenotypes) and compared to that for a susceptible wild-type strain. Microbiologic and inflammatory effects were assessed in a polymicrobial rat model of peritonitis. Mean peritoneal enterococcus concentrations +/- standard deviations at day 1 were 2.1 +/- 1.9, 1.3 +/- 1.1, and 1.7 +/- 2.0 log(10) CFU/ml for susceptible, VanA, and VanB strains, respectively (P < 0.05). At day 3 also there were lower concentrations of glycopeptide-resistant enterococcal strains in peritoneal fluid (3.2 +/- 3.4, 1.8 +/- 1.8, and 2.1 +/- 2.4 log(10) CFU/ml for susceptible, VanA, and VanB strains, respectively [P < 0.05]). Transconjugant glycopeptide-resistant strains were associated with increased peritoneal cell counts at the different evaluation times of the experiment (P < 0.001). Plasma alpha1-acid glycoprotein concentrations were lower in the presence of the susceptible strain (667 +/- 189 mg/liter) than in the presence of the VanA or VanB strain (1,193 +/- 419 or 1,210 +/- 404 mg/liter, respectively [P < 0.05]), while concentrations of tumor necrosis factor alpha and interleukin-6 in peritoneal fluid remained similar for the strains. These results suggest a trend toward variation of virulence of transconjugant strains compared to the wild-type strain in this peritonitis model.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, EMI 9933. Service de Biochimie A, Hôpital Bichat-Claude Bernard, Paris, France.
authors.forename: G
authors.initials: G
authors.lastname: Plantefeve
authors.forename: H
authors.initials: H
authors.lastname: Dupont
authors.forename: V
authors.initials: V
authors.lastname: Hubert
authors.forename: L
authors.initials: L
authors.lastname: Garry
authors.forename: C
authors.initials: C
authors.lastname: Poüs
authors.forename: C
authors.initials: C
authors.lastname: Carbon
authors.forename: P
authors.initials: P
authors.lastname: Montravers
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000382:microbiology; D001835:Body Weight; D002452:Cell Count; D016207:Cytokines / Q000032:analysis; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D006020:Glycopeptides; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology; D008297:Male; D009961:Orosomucoid / Q000032:analysis; D010538:Peritonitis / Q000188:drug therapy* / Q000382:microbiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D016207:Cytokines; D006020:Glycopeptides; D009961:Orosomucoid