Avaliação da resposta imune humoral em caprinos inoculados com vacina atenuada liofilizada contra Corynebacterium pseudotuberculosis

Abstract

Casey lymphadenitis is a chronic disease, characterized by the presence of abscesses in the lymph nodes and organs of production animals, and its etiological agent is Corynebacterium pseudotuberculosis. The transmission is mainly through wounds, that is, direct contact of animals carrying the disease with the healthy ones. Control measures are vaccination and isolation of infected animals. However, the available vaccines do not provide the necessary protection against infection or have not yet been sufficiently tested in the field. The objective of this study was to evaluate the humoral immune response of serum samples from goats inoculated with a lyophilized attenuated vaccine using the 1002 strain of C. pseudotuberculosis by means of an indirect ELISA with BHI antigen. 100 goats, two to three years old, were divided into 5 groups (G1 to G5) with 20 animals each. Groups 1 and 2 received a dose of 107 CFU on day zero and at 21 days G2 was revaccinated. Groups 3 and 4 received a of dose 106 CFU on day zero and at 21 days G4 was revaccinated. Group 5 was considered the control. The animals were followed serologically and clinically for 364 days. The sera collected from the goats were analyzed by the indirect ELISA technique. Despite the O.D. varied during the experiment, there was no statistical difference (p>0.05) between the different doses tested and times of revaccination between the groups. However, it could be inferred that 106 CFU dose is more indicated than 107 CFU in immunization of goats, since a greater loading of the immunogen would not be required for stimulating the humoral response according to the protocol followed in the experiment. In addition, the animals showed antibody production throughout the study, this situation indicates that lyophilized strain 1002 was able to induce an immune response for at least one year.