[Phagocytosis of group A haemolytic streptococci by mouse macrophages. Comparison of preliminary infection of animals and degree of virulence of the strain (author's transl)].

With the aim of studying immunological reactions associated with experimental streptococcal diseases, we have developed an in vitro technique for following phagocytosis of streptococci by peritoneal macrophages of mice. By this means we have been able to show that the rate of phagocytosis of streptococci by "normal" macrophages is inversely correlated to the degree of virulence of the strain. On the other hand, the rate of phagocytosis of the virulent strain is increased 10 times when the macrophages come from mice having previously been injected with this virulent strain.