[Antigenic makeup of the protective fractions of S. typhimurium]

The authors present the results of chemical and immunochemical study of 4 protective fractions (Grasset's antigens, hydroxylamine vaccines, surface antigens, and Boivin's antigens) isolated from the virulent S. typhimurium strain, and of suppressor revertant obtained from streptomycin-dependent mutant of the initial strain. Despite some differences in their chemical and antigenic composition, Grasset's antigens, surface antigens fraction, and hydroxylamine vaccine contained the main cell protective substances and could be used (after further study) as vaccines for enteral immunization. On the basis of the results of chemical analysis and the study of Boivin's antigens antigenic structure it is supposed that O-antigen was changed in the revertant strain.