CAMPYLOBACTER-JEJUNI IN BROILER-CHICKENS - COLONIZATION AND HUMORAL IMMUNITY FOLLOWING ORAL VACCINATION AND EXPERIMENTAL-INFECTION

A formalin inactivated, Campylobacter jejuni whole cell vaccine, eithe r with or without Escherichia coli heat labile toxin (LT) as a mucosal adjuvant, was administered orally to broiler chickens. Three vaccine trials were performed, differing in the number of vaccinations, and ti me of administration, as well as the inclusion and dose of LT. The ove rall reductions of C. jejuni colonization in the vaccinated chickens r anged from 16 to 93% compared with non-vaccinated controls. Enhanced l evels of anti-C. jejuni secretory IgA antibodies were demonstrated in vaccinated chickens. Vaccination also appeared to induce an anamnestic response to C. jejuni antigens in the 14-33 kDa range, as demonstrate d by Western immunoblots. Interestingly, the inclusion of LT in the va ccine regimen did not appear to boost the immunogenicity of the vaccin e. These results are encouraging and suggest that future development o f successful oral vaccines for the control of enteropathogenic Campylo bacter in poultry is feasible. (C) 1997 Elsevier Science Ltd.