Background Salmonella enterica serovar Choleraesuis ( S . Choleraesuis) infection causes a systemic disease in pigs. Vaccination could represent a solution to reduce prevalence in farms. In this study, we aimed to assess the efficacy of an attenuated strain of Salmonella enterica serovar Typhimurium ( S . Typhimurium ΔznuABC ) against S . Choleraesuis infection. The vaccination protocol combined priming with attenuated S . Typhimurium ΔznuABC vaccine and boost with an inactivated S . Choleraesuis vaccine and we compared the protection conferred to that induced by an inactivated S . Choleraesuis vaccine. Methods The first group of piglets was orally vaccinated with S. Typhimurium ΔznuABC and boosted with inactivated S . Choleraesuis, the second one was intramuscularly vaccinated with S. Choleraesuis inactivated vaccine and the third group of piglets was unvaccinated. All groups of animals were challenged with a virulent S. Choleraesuis strain at day 35 post vaccination. Results The results showed that the vaccination protocol, priming with S. Typhimurium ΔznuABC and boosted with inactivated S . Choleraesuis, applied to group A was able to limit weight loss, fever and organs colonization, arising from infection with virulent S . Choleraesuis, more effectively, than the prime-boost vaccination with homologous S . Choleraesuis inactivated vaccine (group B). Conclusion In conclusion, these research findings extend the validity of attenuated S. Typhimurium ΔznuABC strain as a useful mucosal vaccine against S. Typhimurium and S . Choleraesuis pig infection. The development of combined vaccination protocols can have a diffuse administration in field conditions because animals are generally infected with different concomitant serovars.
【저자키워드】 mucosal vaccine, IFN-gamma, salmonellosis, Piglets, Salmonella Choleraesuis, Attenuated and inactivated vaccines,