title: Genetic and phenotypic analysis of biofilm phenotypic variation in multiple Staphylococcus epidermidis isolates.
abstract: Production of biofilm in Staphylococcus epidermidis is mediated through enzymes produced by the four-gene operon ica and is subject to phenotypic variation. The purpose of these experiments was to investigate the regulation of ica and icaR transcription in phenotypic variants produced by multiple unrelated isolates of S. epidermidis. Ten isolates were chosen for the study, four of which contained IS256. IS256 mediates a reversible inactivation of ica in approximately 30 % of phenotypic variants. All ten strains produced at least two types of phenotypic variant (intermediate and smooth) in which biofilm formation was significantly impaired. Reversion studies indicated that all phenotypic variants were stable after overnight growth, but began to revert to other phenotypic forms after 5 days of incubation at 37 degrees C. ica transcriptional analysis was performed on phenotypic variants from three IS256-negative isolates; 1457, SE5 and 14765. This analysis demonstrated that ica transcription was significantly reduced in the majority of phenotypic variants, although two variants from SE5 and 1457 produced wild-type quantities of ica transcript. Analysis of seven additional phenotypic variants from SE5 revealed that ica expression was only reduced in three. Expression of icaR transcript was unaffected in all smooth phenotypic variants. Mutations within ica were identified in two SE5 variants with wild-type levels of ica transcription. It is concluded that mutation and transcriptional regulation of ica are the primary mechanisms that govern phenotypic variation of biofilm formation within IS256-negative S. epidermidis.
authors.affiliation: Departments of Pathology and Microbiology1 and Internal Medicine3, University of Nebraska Medical Center, Omaha, NE, USA 2Department of Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland 4Department of Biology, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: L D
authors.initials: LD
authors.lastname: Handke
authors.affiliation: Departments of Pathology and Microbiology1 and Internal Medicine3, University of Nebraska Medical Center, Omaha, NE, USA 2Department of Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland 4Department of Biology, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Conlon
authors.affiliation: Departments of Pathology and Microbiology1 and Internal Medicine3, University of Nebraska Medical Center, Omaha, NE, USA 2Department of Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland 4Department of Biology, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Slater
authors.affiliation: Departments of Pathology and Microbiology1 and Internal Medicine3, University of Nebraska Medical Center, Omaha, NE, USA 2Department of Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland 4Department of Biology, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: S
authors.initials: S
authors.lastname: Elbaruni
authors.affiliation: Departments of Pathology and Microbiology1 and Internal Medicine3, University of Nebraska Medical Center, Omaha, NE, USA 2Department of Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland 4Department of Biology, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: F
authors.initials: F
authors.lastname: Fitzpatrick
authors.affiliation: Departments of Pathology and Microbiology1 and Internal Medicine3, University of Nebraska Medical Center, Omaha, NE, USA 2Department of Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland 4Department of Biology, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: H
authors.initials: H
authors.lastname: Humphreys
authors.affiliation: Departments of Pathology and Microbiology1 and Internal Medicine3, University of Nebraska Medical Center, Omaha, NE, USA 2Department of Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland 4Department of Biology, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: W P
authors.initials: WP
authors.lastname: Giles
authors.affiliation: Departments of Pathology and Microbiology1 and Internal Medicine3, University of Nebraska Medical Center, Omaha, NE, USA 2Department of Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland 4Department of Biology, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Rupp
authors.affiliation: Departments of Pathology and Microbiology1 and Internal Medicine3, University of Nebraska Medical Center, Omaha, NE, USA 2Department of Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland 4Department of Biology, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: P D
authors.initials: PD
authors.lastname: Fey
authors.affiliation: Departments of Pathology and Microbiology1 and Internal Medicine3, University of Nebraska Medical Center, Omaha, NE, USA 2Department of Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland 4Department of Biology, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: O'Gara
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D015964:Gene Expression Regulation, Bacterial; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000382:microbiology; D013212:Staphylococcus epidermidis / Q000145:classification* / Q000235:genetics / Q000254:growth & development; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins