METHOD FOR PRODUCING CATTLE NECROBACTERIOSIS ANTIGEN Russian patent published in 1995 - IPC

FIELD: veterinary medicine. SUBSTANCE: method involves using locally occurred strain of necrobacteriosis pathologic agent or one selected for a given farm for being cultured under anaerobic conditions to produce bacterial suspension. Cultivation is finished at the stage the culture is characterized with the maximum optical density and pathogenicity when applied to laboratory animals (white mice). Antigen, separated from inactivated bacterial mass is cytoplasmic fraction having pronounced activity in indirect immunofluorescence reaction with homologic blood sera and heterologic ones of the same species. The so obtained antigen differs from polysaccharide antigens in having immunogenic activity and invokes insusceptibility to infection in 50-80% of white mice in 14-20 days after their being immunized as well as prevents cattle from being infected with necrobacteriosis within 6 months after their being vaccinated. EFFECT: steady immunity against necrobacteriosis in cattle. 2 tbl