Effects of subinhibitory concentrations of antibiotics on Staphylococcus aureus interactions with fibronectin

Bacterial adherence to host tissues relies on interactions between tissue macromolecules and bacterial surface molecules. One of the major predisposing factors to infection with Staphylococcus aureus is trauma to tissues. A common element in traumatized tissues is fibronectin. In previous studies, we have shown that fibronectin binds to Staph. aureus. In this paper, we have investigated the effects of subinhibitory concentrations of antibiotics on fibronectin interactions with Staph. aureus. Exposure of Staph. aureus to 1/4 MIC of penicillin increases the number of binding sites and enhances adherence of Staph. aureus to a collagen-fibronectin matrix. Chloramphenicol, erythromycin, clindamycin, and U57,930E all decreased the number of binding sites. Also, U57,930E reduced Staph. aureus adherence to a collagen-fibronectin matrix. Taken together, these data suggest that penicillin may enhance Staph. aureus adherence to tissue fibronectin whereas U57,930E might reduce such binding.