Segurança e eficácia da vacina PBB-001 frente ao Dichelobacter nodosus em condições de campo

Abstract

Ovine footrot is a highly contagious disease of sheep that results in lameness and substantial production loss. The disease is caused for two pathogens, the primary pathogen is a gram-negative, anaerobic bacterium Dichelobacter nodosus and a second pathogen gramnegative anaerobic bacterium, Fusobacterium necrophorum. Vaccine developments to induce high antibodies titers are important for control of disease. The present work evaluated the safety and afficacy of the PBB-001 vaccine against the contagious ovine pododermatitis (footrot) under field conditions in a endemic region of the disease. The experiment was performed between May and December of 2011, in 2 properties located in Dom Pedrito-RS. For this experiment we used 140 female sheep, Corriedale breed, with an average age of 8 months, segregated in 2 groups where 1 group received PBS (placebo), and the other received the vaccine to be tested. Each group received 3 dosis of 2ml/animal, at days 0, 21 e 175. Antibody titers of the ELISA for D. nodosus presented significant difference (P<0,001) at 60 days and highly significant (P<0,0001) at 30 and 185 days, between the groups tested. Results showed that the disease occurrence in the vaccinated animals was 2,85% against 17,14% on the unvaccinated animals. In addition to that, PBB001 vaccine had over 80% efficacy and absence of local and general clinical signs in all animals. Together, these results show that PBB001 vaccine presents efficacy and safety needed for the control and prevention of the ovine foot-rot.