Este trabalho teve o objetivo de avaliar a reação de imunofluorescência indireta (RIFI), ensaio imunoenzimático (ELISA) e a reação de fixação do complemento (RFC) no diagnóstico de Theileria equi em amostras de soro de 79 equinos na Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ, Brasil. Houve reação positiva para Theileria equi em 74,7, 75,9 e 60,8% das amostras testadas pela RIFI, ELISA e RFC, respectivamente. Observou-se discrepância em 16,45% (n=13) das amostras de soro testadas pelo ELISA indireto e RIFI. Quando comparado a RIFI e a RFC, a discrepância observada entre os soros testados foi de 36,70% (n=29). O teste ELISA indireto e a RFC apresentaram discordância em 37,97% (n=30) das amostras de soros. Os resultados do presente estudo sugerem que a melhor alternativa para o diagnóstico sorológico de T. equi em eqüinos portadores é a associação dos testes de RIFI e ELISA indireto, especialmente para a realização de estudos soroepidemiológicos.

Phenotypic and antigenic variations among Mycoplasma gallisepticum vaccine F and Ts-11 strains were investigated by SDS-PAGE and serological methods (hemagglutination-inhibition and immunoblot assays). The SDS-PAGE system followed by densitometer analysis showed weak phenotypic variability between the strains, being the major difference close to the 75 kDa level where a prominent peptide band was detected only in the F vaccine strain. Polyclonal antibodies to the M. gallisepticum antigens produced in chickens were used in serological tests for this antigenic variability study. There were strong cross-reactions between the strains and homologous/ heterologous antibodies. The most evident characteristic was the specific response of the vaccine-type F polyclonal antiserum to the 75 kDa peptide band of the homologous strain.

The Mycoplasma gallisepticum strains [wild-type S6 (208) and a vaccine-type F-K810] grown in Frey´s and Hayflick´s media were analyzed by SDS-PAGE. No visual changes in the protein profiles of these strains were observed regardless of the media composition used, although the polyacrylamide gel electrophoretograms showed minor differences do exist when densitometer traces of the gel are compared. Both strains were easily differentiated on SDS-PAGE analysis by a peptide band p75, that is specific for MG F-K810 strain, used as vaccine.