title: Biofilm synthesis and presence of virulence factors among enterococci isolated from patients and water samples.
abstract: The goal of this study was to compare biofilm synthesis among enterococci recovered from clinical samples (infection or colonization) of patients as well as environmental samples in order to determine possible virulence factors and clonal relationship. During a two-year period, clinical samples (blood, catheter tips, bronchial secretions, wounds, peritoneal fluid, urine) and rectal swabs collected from hospitalized patients as well as environmental water samples were tested for the presence of Enterococcus faecalis and Enterococcus faecium. Antibiotic susceptibility testing was performed by the disc diffusion method and Etest. Strains were tested for the presence of vanA, vanB, esp, ace and asp genes by PCR. Clones were identified by PFGE (SmaI). From infected patients, 48 strains were identified: 24 Enterococcus faecium (10 vanA-positive, 14 vancomycin-susceptible) and 24 Enterococcus faecalis (one vanA-positive, 23 vancomycin-susceptible). Among 143 colonizing isolates, 134 were Enterococcus faecium (58 vanA-positive, 11 vanB-positive, 65 vancomycin-susceptible) and nine Enterococcus faecalis (three vanA-positive, two vanB-positive, four vancomycin-susceptible). Among 167 environmental water samples, 51 Enterococcus faecalis and 19 Enterococcus faecium isolates, all glycopeptide-susceptible, were recovered. In total, 64 strains produced biofilm, whereas 34 were esp-positive, 64 asp-positive and 54 ace-positive. Biofilm production was associated with the presence of esp (P < 0.001) and ace genes (P = 0.021), being higher in infecting (P < 0.001) and water (P 0.005) isolates as compared with colonizing ones. Clones of environmental water-strains were different than the patients' clones. The differences found in the incidence of antibiotic resistance, virulence factors and clones suggest that hospital and water enterococci are of different origin.
authors.affiliation: Division of Infectious Diseases, School of Medicine, University of Patras, Patras, Greece.
authors.forename: Matthaios
authors.initials: M
authors.lastname: Papadimitriou-Olivgeris
authors.affiliation: Environmental Microbiology Unit, Department of Public Health, School of Medicine, University of Patras, Patras, Greece.
authors.forename: Sevasti
authors.initials: S
authors.lastname: Filippidou
authors.affiliation: Department of Microbiology, School of Medicine, University of Patras, Patras, Greece.
authors.forename: Eleanna
authors.initials: E
authors.lastname: Drougka
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, School of Medicine, University of Patras, Patras, Greece.
authors.forename: Fotini
authors.initials: F
authors.lastname: Fligou
authors.affiliation: Department of Microbiology, School of Medicine, University of Patras, Patras, Greece.
authors.forename: Fevronia
authors.initials: F
authors.lastname: Kolonitsiou
authors.affiliation: Intensive Care Unit, General Hospital 'Saint Andrew', Patras, Greece.
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Dodou
authors.affiliation: Division of Infectious Diseases, School of Medicine, University of Patras, Patras, Greece.
authors.forename: Markos
authors.initials: M
authors.lastname: Marangos
authors.affiliation: Department of Microbiology, School of Medicine, University of Patras, Patras, Greece.
authors.forename: Evangelos D
authors.initials: ED
authors.lastname: Anastassiou
authors.affiliation: Environmental Microbiology Unit, Department of Public Health, School of Medicine, University of Patras, Patras, Greece.
authors.forename: Apostolos
authors.initials: A
authors.lastname: Vantarakis
authors.affiliation: Department of Microbiology, School of Medicine, University of Patras, Patras, Greece.
authors.forename: Iris
authors.initials: I
authors.lastname: Spiliopoulou
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms; D016983:Enterococcus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology*; D005618:Fresh Water / Q000382:microbiology*; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors