Abstract: | Epithelial cells of the HEp-2 line infected in parallel by genetically connected strains of Sh. flexneri, differing in the capacity to synthesize the type antigen were studied morphologically. The type antigen proved to show no significant influence on the penetration of dysentery bacilli into the cell. A study of the process of phagocytosis of the mentioned strains by a culture of peritoneal macrophages of guinea pig demonstrated that the presence of a type antigen communicated to the bacteria some selective advantages within the macrophages increasing their resistance to the action of the digestive enzymes. |