STUDY OF PATHOGENICITY AND IMMUNOGENICITY OF PASTEURELLA MULTOCIDA RECENTLY ISOLATED FROM INFECTED RABBITS

Abstract

In this study, 150 samples were collected from rabbits in infected farms which show high mortality suspected to be affected with Pasteurellosis. Thirty of Pasteurella multocida isolates were obtained which were belonged to serotypes A:3, A:3,5, A:12, B:2, D:6 and uncommon types as A:4 and D:12. The determination of pathogenicity and immunogenicity of these isolates (in mice) indicated that some of these isolates were highly pathogenic, others are of moderate or low pathogenicity. The protective value was good in serotypes A:3, A:3,5, A:12, B:2, D:6 which gave high protective value (more than 2 log), when vaccinated mice were challenged with homologous strains. Rabbits vaccinated with currently used vaccine and challenged with homologous strains and heterologous recently isolates gave good immune response except with field serotypes B:2 and D:6.