5^th Animal Health and Veterinary Medicine Congress

Biography

Biography: Fernanda Washington de M. Lima

Abstract

Toxoplasma gondii is the primary abortion-causing agent by infectious disease in goats. Moreover, intake of meat and milk from infected animals can facilitate zoonotic transmission. Thus, investigating the immune response against T. gondii is very important for understanding the pathogenesis of the disease in order to develop control strategies and immunoprophylaxis. The aim of this study was to investigate aspects of the humoral and cellular immune response of goats experimentally infected with TOX31 and RH strains of T. gondii. The humoral immune response was evaluated through the levels of anti-T. gondii antibodies using ELISA, while cell response was investigated by determination of IFN-gamma concentration in supernatant of culture from peripheral blood cell of infected and control animals. The study was conducted with 21 goats divided into three groups of 7 animals each one (n = 7): a negative control and two experimentally infected groups with HR or TOX 31 strains, respectively. Infected animals showed a rapid humoral immune response with seroconversion to IgG antibodies at day 15, which reached maximum levels in the sixtieth day after infection. The "in vitro" stimulation for animals inor to the RH strain. Histopathological study showed major changes in the animal inoculatculated with the HR strain with T. gondii antigen, in different concentrations of total proteins, produced a high concentration of IFN-gamma on day 15 post infection. Only at higher antigen concentrations (300mg / ml), the animals infected with strain TOX31 and the negative control showed IFN-gamma increases similaed with RH strain as hyperplasia of the submandibular lymph nodes and lung lymphoid tissue. In general, IgG levels of anti-T. gondii and IFN-gamma were higher in goats group infected with T. gondii from RH than from TOX31 strain. Thus, the RH strain demonstrates higher immunogenicity than the TOX31.