Role of fibronectin in the adherence of Staphylococcus aureus to dermal tissues

Staphylococcus aureus has a fibronectin receptor on its surface. Fibronectin seems to play a role in the initiation and modification of infection with S. aureus. We studied the role of fibronectin in the binding of S. aureus (clinical isolates) to dermal tissues in mice, and the relationship between the fibronectin binding ability of S. aureus and clinical features of S. aureus skin infections. Mice were inoculated with S. aureus incubated with gold-particles bound fibronectin and skin specimens were taken for electron microscopic examination. The number of gold particles surrounding the S. aureus cells decreased with time, with none detected 4 h after inoculation. At both 5 min and 1 h after inoculation, gold particles were only found on the free surface of S. aureus cells and not in the interface between S. aureus cells and fibroblasts. Fibronectin-bound gold particles were bound more extensively to S. aureus strains isolated from furunculosis or furuncle than to those from bullous impetigo. These results suggest that the matrix fibronectin on the surface of the fibroblasts of mice contributes to the adherence of S. aureus to the fibroblasts, and that the number of fibronectin binding sites on S. aureus cells is related to the degree of local invasiveness.