An in vitro study of antibody-induced inhibition and detachment of Staphylcocci from fibrinogen

Staphylococcus aureus is a major human pathogen and is associated with several infectious diseases. S. aureus Newman has been shown to bind to fibrinogen under dynamic conditions. In this study the adhesion and detachment from fibrinogen was quantified and studied under in vitro physiological shear conditions. The efficacies of five monoclonal antibodies (mAbs) to facilitate adhesion inhibition and detachment were evaluated using a parallel plate flow chamber and video microscopy system. We found that two mAbs to clumping factor A inhibited adhesion and caused detachment of adherent S. aureus cells. Inhibition was highest at mAb concentrations of 10 mg/ml where percent inhibition was at 90% and independent of shear stress. The highest levels of detachment were reached at a shear rate of 300 s^-1 and antibody concentration of 5 mg/ml. These data suggest that the two mAbs may have the potential to cause reduced virulence of S. aureus.