[The detection of the Shiga toxin antigen in connection with other virulence factors--the O and K antigens of enterobacteria]. / Vyiavlenie antigena shigatoksina v sviazi s drugimi faktorami virulentnosi--O- i K-antigenami énterobakterii.

The results of the detection of Shiga toxin antigen in culture filtrates of 73 enterobacterial strains by the methods of countercurrent electrophoresis and coagglutination, as well as their correlation with the presence of other factors of virulence, O- and K-antigens, have been analyzed. Sharply pronounced inverse correlation between the capacity of enterobacteria to synthesize Shiga (Shiga-like) toxins and their capacity to synthesize acidic polysaccharide surface-specific K- (Vi-) antigens has been established.

[Electron microscopic study of the interaction of virulent and avirulent Shigella flexneri strains with the macrophages of murine peritoneal exudate]. / Elektronno-mikroskopicheskoe izuchenie vzaimodeistviia virulentnogo i avirulentnogo shtammov Shigella flexneri s makrofagami peritoneal'nogo ékssudata myshei.

The electron microscopic dynamic study of the interaction of S. flexneri virulent strain 2a and S. flexneri avirulent strain, genetically related to strain 2a and having the same antigenic structure, with peritoneal macrophages of CBA mice at an early period showed differences in the cytotoxic action of these strains. Even at the early period of the interaction between macrophages and virulent shigellae structural changes were observed in macrophages: ruptures in the membranes of parasitophore phagosomes, the vacuolization of the cytoplasm, the destruction of mitochondria. These changes were indicative of the early cytotoxic action of shigellae belonging to the virulent strain. In macrophages infected with avirulent shigellae the manifestations of this cytotoxicity were less pronounced and appeared later than in macrophages infected with S. flexneri virulent strain.