Adherence of Staphylococcus aureus to cultures of human peritoneal mesothelial cells

Strains of Staphylococcus aureus, isolated from the effluentof patients with peritonitis on CAPD (continuous ambulatoryperitoneal dialysis), adhered well to both cultured human mesothelialcells and to fibronectin, but not to laminin or gelatin. Mesothelialcells grown in medium M199 exhibited more surface fibronectincompared to cells grown in MEM-Dval and demonstrated higherlevels of S. aureus adherence. Soluble fibronectin concentrations up to lOµg/ml increasedthe adherence of S. aureusto cultured mesothelial cells. Thedose-response curve was consistent with the binding of fibronectinto a saturable receptor of apparent dissociation constant (K_D)= 1.7xlO^–10 M. This corresponds closely to the K_D (2xlO^–10M) of the staphylococcal fibronectin-binding protein. S. aureus adherence was increased following the preincubationof mesothelial cell monolayers with interleukin-1 and was maximalafter 6 h preincubation. Treating mesothelial cells with interferon-gammafor 48–72 h reduced the adherence of S. aureus.