Anticorpos anti-Neospora caninum em novilhas após vacinação ou infecção experimental e em amostras de leite

• Ano de defesa: 2011
• Autor(a) principal: Camillo, Giovana
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; BR; Medicina Veterinária; UFSM; Programa de Pós-Graduação em Medicina Veterinária
• Palavras-chave em Português: Vacinação; Diagnóstico; RIFI; Rebanhos; Leite; Leite coletivo; Vaccination; Diagnosis; IFA; Herds; Milk; Bulk milk; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA
• Link de acesso: http://repositorio.ufsm.br/handle/1/10092

Neosporosis is an economically important disease caused the protozoan Neospora caninum and is characterized by causing reproductive problems in cattle such as abortion, return to estrus and birth of calves persistently infected. The diagnosis is based mainly on detection of antibodies anti-N.caninum by serological tests, from samples of blood serum and also through milk. The control of this disease is related to the culling of positive animals that showing reproductive disorders, since no commercially available vaccine induces immune response able of preventing transplacental transmission and thus, the parasite remains in the herd. In this study, we performed studies involving the humoral response against the parasite and the detection of antibodies in individual and bulk milk samples for the indirect immunofluorescence assay (IFA). The results are presented in three manuscripts. In chapter one, the aim was to compare serum immunoglobulin G and M, in animals experimentally infected with tachyzoites of NC-1 strain, and animals vaccinated with an inactivated vaccine. The results showed a clear oscillation in antibody titers, revealing that the heifers inoculated immune response was more durable than in those vaccinated. In the second chapter, it was performed a diagnostic test of the anti-N.caninum antibodies from milk samples, using as a test, IFA. When analyzing individual samples of milk, there was a good correlation for samples of blood serum. The higher the serum titer, the greater the probability of detecting antibodies in milk samples, both individual and bulk milk. In chapter three, the aim it was to evaluate the use of bulk milk sample for herd diagnostic or for epidemiological studies, by detecting antibodies. Similar to results obtained in chapter two, the bulk milk sample, when analyzed by IFA demonstrated to be correlated with the number of positive animals in each herd as well as with the titles presented by these animals. Thus, through this study we emphasize that with regard to vaccination, more work needs to be better conducted in order to get an immune response able to protect the fetus longer more time and more importantly, that will prevent or reduce transplacental transmission. Regarding the diagnosis by using the milk samples it was observed that both samples in individual and bulk milk, the IFA can be used safely and is considered an easier way to carry out epidemiological studies in herd cattle.