RESUMO
The significance of maternal immunity against non-typhoid Salmonella spp. acquired by piglets via colostrum and milk was evaluated in a Salmonella enterica serovar Typhimurium challenge experiment. Piglets from sows vaccinated with an experimental inactivated vaccine exhibited high levels of serum immunoglobulins G and A against S. Typhimurium 4 days after birth, just prior to experimental oral challenge. The S. Typhimurium load in the ileal and caecal wall of piglets 3 days after experimental inoculation was lower by a 2-log magnitude compared to unvaccinated controls. Such a vaccine, delivering colostral/lactogenic immunity to piglets thus has the potential to reduce the prevalence non-typhoid Salmonella spp. infection.
Assuntos
Vacinas Bacterianas/imunologia , Imunidade Materno-Adquirida , Salmonelose Animal/imunologia , Salmonella typhimurium/imunologia , Doenças dos Suínos/imunologia , Animais , Animais Recém-Nascidos , Carga Bacteriana/veterinária , Ceco/microbiologia , Colostro/imunologia , Feminino , Íleo/microbiologia , Imunidade nas Mucosas , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Leite/imunologia , Salmonelose Animal/microbiologia , Suínos , Doenças dos Suínos/microbiologia , Vacinas de Produtos Inativados/imunologiaRESUMO
The first aim of our study was to obtain information on the transmission of antigen-specific antibodies from colostrum to respiratory tract mucosa in piglets. The second aim was to confirm the biological relevance of the presence of lymphocytes in colostrum and the already described fact that these cells can penetrate the intestinal barrier and "colonize" peripheral blood and lymphatic tissues of piglets. Therefore, we performed an experiment in which sows were immunized with a model antigen Keyhole Limpet Hemocyanin and their piglets were euthanized at different intervals after birth and colostrum intake. Colostrum, bronchoalveolar lavage fluid and blood samples were collected for serological detection of antigen-specific antibodies. Lymphocytes isolated from peripheral blood and lymphatic tissues (mesenteric and tracheobronchial lymph nodes and spleen) of piglets were in vitro activated with the antigen. We found that colostrum-derived antibodies can cross into the respiratory tract mucosa. Furthermore, we found that antigen-specific lymphocytes were detectable in mesenteric lymph nodes and peripheral blood, but very rarely in spleen and tracheobronchial lymph nodes.
