ABSTRACT
The resistance to phagocytosis of the group A streptococci has been attributed mainly to the presence of the surface antigen, M protein. In the present study, we addressed the question of whether the phagocytosis resistance of the group A streptococci is due to their ability to impair the function of the phagocytic cells. The results of these studies demonstrate that the presence of a large excess of a phagocytosis-resistant strain of streptococci does not significantly interfere with either the antibody-independent or the antibody-dependent phagocytosis of streptococci. Apparently, a phagocytosis-resistant strain of streptococci does not bring about a generalized deactivation of the phagocytic plasma membrane. This suggests that if the resistance of the group A streptococci is due to any deactivating influence at all on the phagocytic plasma membrane, it is likely to be confined to the contact area of the cocci with the phagocyte.
