title: Biofilm characteristics of Staphylococcus epidermidis isolates associated with device-related meningitis.
abstract: Staphylococcus epidermidis biofilm causes device-related meningitis in neurosurgical patients. This study assessed the contribution of polysaccharide and protein to the development of a strong biofilm-positive phenotype in four S. epidermidis isolates associated with probable device-related meningitis, under varying environmental conditions. RT-PCR analysis of the intercellular adhesion operon (icaADBC) and assessment of polysaccharide intercellular adhesin (PIA) production indicated a correlation between increased icaA transcription and PIA production in ica(+) isolates grown in medium with 4 % ethanol and 4 % NaCl. Treatment of biofilm with sodium metaperiodate caused dispersion of adhered cells (P <0.0001), indicating involvement of PIA. Transcriptional levels of protein factors revealed that atlE transcription levels were similar in all isolates, whilst aap levels were variable, with induction being seen in two isolates following growth in the presence of alcohol or salt. Transcription of agr did not influence protein expression and RNAIII transcription varied among the strains. Although aap transcription was induced, the treatment of biofilm with proteinase K did not always disperse the biofilm. Our data suggest that, among the three ica(+) S. epidermidis isolates clinically associated with meningitis that were studied, PIA contributed to the strong biofilm-positive phenotype, whereas protein factors appeared to have a secondary role.
authors.affiliation: Department of Clinical Microbiology, Royal College of Surgeons in Ireland Education & Research Centre, Beaumont Hospital, Dublin 9, Ireland.
authors.forename: Niall T
authors.initials: NT
authors.lastname: Stevens
authors.affiliation: Department of Medicine, Royal College of Surgeons in Ireland Education & Research Centre, Beaumont Hospital, Dublin 9, Ireland.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Greene
authors.affiliation: School of Biomolecular & Biomedical Science, University College Dublin, Dublin 4, Ireland.
authors.forename: James P
authors.initials: JP
authors.lastname: O'Gara
authors.affiliation: Department of Microbiology, Beaumont Hospital, Dublin 9, Ireland.|Department of Clinical Microbiology, Royal College of Surgeons in Ireland Education & Research Centre, Beaumont Hospital, Dublin 9, Ireland.
authors.forename: Hilary
authors.initials: H
authors.lastname: Humphreys
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms; D004864:Equipment and Supplies / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D006801:Humans; D016920:Meningitis, Bacterial / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins