Аннотация
The article presents the results of studies on the study of cultural, tinctorial, biochemical and virulence properties of Pasteurella multocida strains isolated from cattle. In order to refresh the isolated strains and increase their virulent properties, successive passages were carried out through the body of white mice. According to the results of the bioassays, a reduction in the period of death of mice after infection with Pasteurella cultures was established, which proves an increase in their virulence. When studying the cultural and morphological properties, pure cultures of Pasteurella were grown on nutrient media at 37°C for 18–24 h. A biochemical test on Hiss medium was used to fully confirm the data obtained. The test cultures isolated from pathological material (heart, lung, spleen, liver, intestines ) of cattle have cultural, biochemical and biological properties characteristic of the Pasteurella multocida species and form S-shaped colonies. Isolated cultures of Pasteurella multocida can be used to evaluate the immunogenicity of existing vaccines and use them as a basis for the development of anti-pasteurellosis polyvalent emulsion vaccines, anti-pasteurellosis hyperimmune serum and e.t.c.