Fibronectin and proteolytic fragments of fibronectin interfere with the adhesion of Staphylococcus epidermidis to plastic

Abstract

The adhesion of five strains of slime-positive Staphylococcus epidermidis to plastic microwells was significantly diminished (P < 0.005) in a concentration-dependent fashion when wells were previously coated with increasing concentrations (1.6-13.1 micrograms cm-2) of human fibronectin (FN). The adhesion of four of five strains was significantly reduced when wells were coated with 3.2 micrograms cm-2 of FN and at concentrations > or = 6.5 micrograms cm-2 the adhesion of all slime-positive strains was significantly reduced. The coating of microwells with chymotryptic fragments of FN containing the heparin-binding, gelatin-binding, or cell-binding domains also reduced bacterial adhesion but none of the fragments exceeded the anti-adhesive activity of intact FN. A comparison of FN-coated or albumin-coated microwells showed that both proteins caused a significant reduction in the adhesion of test strains to plastic but that the anti-adhesive activity of FN was greater than albumin at all concentrations tested. The adhesion of the slime-negative phase variant of one of the test strains to plastic was neither enhanced nor reduced by FN coating indicating that the production of an exopolysaccharide by Staph. epidermidis influences interactions with protein-coated surfaces. These results support the contention that FN does not mediate the adhesion of all strains of Staph. epidermidis to plastic surfaces.