title: Adhesion to bile drain materials and physicochemical surface properties of Enterococcus faecalis strains grown in the presence of bile.
abstract: The aim of this study is to determine whether growth in the presence of bile influences the surface properties and adhesion to hydrophobic bile drain materials of Enterococcus faecalis strains expressing aggregation substance (Agg) or enterococcal surface protein (Esp), two surface proteins that are associated with infections. After growth in the presence of bile, the strains were generally more hydrophobic by water contact angles and the zeta potentials were more negative than when the strains were grown in the absence of bile. Nitrogen was found in lower surface concentrations upon growth in the presence of bile, whereas higher surface concentrations of oxygen were measured by X-ray photoelectron spectroscopy. Moreover, an up to twofold-higher number of bacteria adhered after growth in bile for E. faecalis not expressing Agg or Esp and E. faecalis with Esp on its surface. E. faecalis expressing Agg did not adhere in higher numbers after growth in bile, possibly because they mainly adhere through positive cooperativity and less through direct interactions with a substratum surface. Since adhesion of bacteria is the first step in biomaterial-centered infection, it can be concluded that growth in bile increases the virulence of E. faecalis.
authors.affiliation: Department of Medical Microbiology. Department of Biomedical Engineering, University of Groningen, 9713 GZ Groningen, The Netherlands. k.waar@med.rug.nl
authors.forename: Karola
authors.initials: K
authors.lastname: Waar
authors.forename: Henny C
authors.initials: HC
authors.lastname: van der Mei
authors.forename: Hermie J M
authors.initials: HJ
authors.lastname: Harmsen
authors.forename: John E
authors.initials: JE
authors.lastname: Degener
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Busscher
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism; D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000378:metabolism; D001646:Bile / Q000378:metabolism*; D003470:Culture Media; D013293:Enterococcus faecalis / Q000737:chemistry / Q000254:growth & development* / Q000502:physiology; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008565:Membrane Proteins / Q000378:metabolism; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D018829:Adhesins, Bacterial; C402603:Asa373; D001426:Bacterial Proteins; D003470:Culture Media; D008565:Membrane Proteins; C065937:aggregation substance, Enterococcus faecalis; C116707:enterococcal surface protein, esp