[Changes in the toxic, antigenic and immunogenic properties of the O-antigen of Salmonella gallinarum-pullorum irradiated with gamma rays].

Studied was the effect of gamma-rays at rates of 1 to 20 MR on the toxic, antigenic, and immunogenic properties of the O-antigen extracted from Salmonella gallinarum-pullorum by the method of Boivin. It was found that the irradiation of aqueous solutions of the O-antigen lowered the toxic, antigenic, and immunogenic capacity with the increase in the dose of treatment. Strongest detoxication of the endotoxin was produced through irradiation at the rate of 10 MR, and especially at 20 MR. The antigenic activity, established through the hyperimmunization of rabbits was expressed best at irradiation rates of 1 and 5 MR. At such treatments the immunogenic capacity remained intact as followed up by the murine protection test.