[The immunity indices in an experimental infection caused by Yersinia enterocolitica O3 and O9].

Some characteristics of cell reactions in the lymphoid organs of the immune system (the thymus, the spleen, lymph nodes), nonspecific resistance and specific humoral response in guinea pigs after their enteral infection with Y.enterocolitica serovars O3 and O9, differing in their virulence, were studied. Differences in the course and severity of Yersinia infections in guinea pigs were established: Y.enterocolitica O3 induced the development of the localized process and Y.enterocolitica O9, the generalized process. The reaction of the immune system was characterized by polyclonal immune response with decreased characteristics of nonspecific resistance, by the development of delayed hypersensitivity manifested by cell reactions in the lymphoid organs, by autoimmune reactions in the lymphoid organs, by autoimmune reactions and by the active production of agglutinins; the time of this reaction coincided with the maximum manifestations of the development of the infectious process.