Antiphagocytic Effects of Staphylococcal Protein A

Abstract

Abstract Strains of Staphylococcus aureus possessing large amounts of protein A tended to resist phagocytosis more than strains that contain lesser amounts or none of this protein. Protein A extracted from S. aureus inhibited phagocytosis of both S. aureus and Escherichia coli in in vitro phagocytosis systems. The antiphagocytic effect was produced by nonspecific reaction of protein A with the Fc piece of γG globulin.