title: Biofilm formation by ica-positive and ica-negative strains of Staphylococcus epidermidis in vitro.
abstract: Staphylococcus epidermidis is a clinically important opportunistic pathogen that forms biofilm infections on nearly all types of indwelling medical devices. The biofilm forming capability of S. epidermidis has been linked to the presence of the ica operon in the genome, and the amount of biofilm formation measured by the crystal violet (CV) adherence assay. Six S. epidermidis strains were characterized for their ica status using PCR, and their biofilm forming ability over 6 days, using the CV assay and a flow cell system. Ica-negative strains characterized as 'negative for biofilm formation' based on the CV assay were demonstrated to form strongly attached biofilms after 6 days. However, the biofilms were not as extensive as the ica-positive strains. It was concluded that ica is not required for biofilm formation, nor is the 24-h CV assay generalizable for predicting the 6-day biofilm-forming ability for all S. epidermidis strains.
authors.affiliation: Center for Genomic Sciences, Allegheny-Singer Research Institute, Allegheny General Hospital, Pittsburgh, Pennsylvania, USA.
authors.forename: Bethany
authors.initials: B
authors.lastname: Dice
authors.forename: P
authors.initials: P
authors.lastname: Stoodley
authors.forename: Farrel
authors.initials: F
authors.lastname: Buchinsky
authors.forename: Nalini
authors.initials: N
authors.lastname: Metha
authors.forename: Garth D
authors.initials: GD
authors.lastname: Ehrlich
authors.forename: Fen Z
authors.initials: FZ
authors.lastname: Hu
mesh_terms: D001422:Bacterial Adhesion / Q000235:genetics / Q000502:physiology; D018441:Biofilms / Q000254:growth & development*; D004864:Equipment and Supplies / Q000382:microbiology; D005798:Genes, Bacterial; D009876:Operon / Q000235:genetics; D016133:Polymerase Chain Reaction; D011135:Polysaccharides, Bacterial / Q000235:genetics / Q000502:physiology*; D013212:Staphylococcus epidermidis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism
chemical_list: D011135:Polysaccharides, Bacterial; C113579:polysaccharide intercellular adhesin