[Design of new types of chemical vaccines for the prevention of intestinal infections and problems of their qualitative evaluation. Report 2. Immunochemical characteristics of the experimental preparations].

A study was made of chemical composition and immunochemical properties of 36 samples of the antigenic preparations from typhoid, paratyphoid (A and B) and dysentery (Flexner and Sonne) cultures obtained at the Leningrad, Moscow and Tashkent Institutes of Vaccine and Sera by various methods. The preparations isolated by the method of tryptic proteolysis had a polysaccharide-protein nature, and preparations isolated by the action of chemical reagents (hydroxylamine, hydrogen peroxide, detergents) -- a protein-polysaccharide one. The former contained more nucleic acids, this indicating the presence of components of cytoplasmic and nuclear origin. The preparations were characterized by molecular heterogeneity and contained high- and low-molecular components. The preparations had complex antigenic spectra by the immunodiffusion data; the preparations obtained had complex antigenic spectra by the immunodiffusion data; the preparations obtained had complex antigenic spectra by the immunodiffusion data; the preparations obtained by different method displayed identity reactions, and group specificity was expressed in some of them.