Comparison of three blood-clotting substances in Staphylococcus aureus strains

Besides the two well-known blood-clotting substances, coagulase and clumping factor, a third one has been identified from the staphylococci which is a cell surface polysaccharide, is alkali stable, and induces compact-colony formation in serum soft agar. Using some 97 clinical strains of Staphylococcus aureus, we found that in production and activity the substances were distinctly different.