Humoral immune response of horses experimentally infected with Trypanosoma evansi/ <br> Resposta imune humoral de eqüinos infectados experimentalmente com Trypanosoma evansi

Abstract

Six adult horses were experimentally infected with Trypanosoma evansi (106 parasites). Three other adult horses served as negative control. Serum samples of the experimentally infected horses with T. evansi and non-infected controls horses were obtained before inoculation, and daily thereafter until 14 days post infection (DPI). After that time the serum samples were obtained weekly. Sera of the infected and non-infected control horses was tested by indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against T. evansi. Both ELISA and IFAT detected trypanosomal antibodies shortly after infection and showed progressive increases in antibodies levels during early stages of infection. The responses started on the eighth and eleventh DPI. Maximum IFAT and ELISA values were reached after four weeks of infection and were maintained at this level until the end of the period of study.Seis eqüinos foram inoculados com 106 tripomastigota sangüícolas de Trypanosoma evansi. Três outros animais foram mantidos como testemunhas. Amostras de soro sangüíneo foram obtidas de todos os animais, antes da inoculação, e diariamente até o 14º dia pós inoculação (DPI); após este período uma vez por semana. Pesquisa de anticorpos anti- T. evansi, foram realizadas através da reação de imunofluorescência indireta (RIFI) e do ensaio de imunoabsorção enzimática (ELISA). A resposta imune humoral, detectada através da RIFI e do ELISA, iniciou-se, em média, a partir do oitavo DPI, alcançando títulos máximos após quatro semanas de evolução, e os titulos de anticorpos anti- T. evansi mantiveram-se elevadas até o término das observações.

Keywords

• Trypanosoma evansi
• Tripanossomiase
• Eqüinos
• Resposta imune.