title: Proteomic analysis of Staphylococcus aureus biofilm cells grown under physiologically relevant fluid shear stress conditions.
abstract: BACKGROUND
  The biofilm forming bacterium Staphylococcus aureus is responsible for maladies ranging from severe skin infection to major diseases such as bacteremia, endocarditis and osteomyelitis. A flow displacement system was used to grow S. aureus biofilms in four physiologically relevant fluid shear rates (50, 100, 500 and 1000 s(-1)) to identify proteins that are associated with biofilm.
  
  
  RESULTS
  Global protein expressions from the membrane and cytosolic fractions of S. aureus biofilm cells grown under the above shear rate conditions are reported. Sixteen proteins in the membrane-enriched fraction and eight proteins in the cytosolic fraction showed significantly altered expression (p < 0.05) under increasing fluid shear. These 24 proteins were identified using nano-LC-ESI-MS/MS. They were found to be associated with various metabolic functions such as glycolysis / TCA pathways, protein synthesis and stress tolerance. Increased fluid shear stress did not influence the expression of two important surface binding proteins: fibronectin-binding and collagen-binding proteins.
  
  
  CONCLUSIONS
  The reported data suggest that while the general metabolic function of the sessile bacteria is minimal under high fluid shear stress conditions, they seem to retain the binding capacity to initiate new infections.
authors.affiliation: Current address: Department of Plant Sciences, University of Maryland, College Park, MD 20742, USA.
authors.forename: Nazrul
authors.initials: N
authors.lastname: Islam
authors.affiliation: Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA.
authors.forename: Yonghyun
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Chemical, Biochemical and Environmental Engineering, University of Maryland Baltimore County (UMBC), Baltimore, MD 21250, USA.
authors.forename: Julia M
authors.initials: JM
authors.lastname: Ross
authors.affiliation: Department of Chemical, Biochemical and Environmental Engineering, University of Maryland Baltimore County (UMBC), Baltimore, MD 21250, USA.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Marten
keywords: Biofilm; Flow chamber; Proteomics; Shear stress; Staphylococcus aureus