RESUMO
Capture ELISA and immunoblotting techniques were applied for the detection of Toxoplasma gondii (T.g) circulating antigens (CAG) in serum specimens of OF-1 mice infected with virulent RH, or cystogenic PGD strains. The capture ELISA assay allowed to detect CAG from the first day of infection to the death of animals with the two T.g strains, although CAG rates were higher when the RH strain was used. Immunoblotting confirmed these findings. Moreover, immunoblotting allowed to identify 7 CAG (MW: 22 kDa to 110 kDa) in serum specimens of mice infected with the RH strain and only 3 (MW: 75 kDa to 110 kDa) in serum specimens of mice infected with the PGD strain. These results are discussed in the light of the evolutive ways of experimental infection by T.g.