DIFFERENTIATION AND QUANTIFICATION OF THEILERIA-SERGENTI PIROPLASM TYPES USING TYPE-SPECIFIC MONOCLONAL-ANTIBODIES

Antigenic properties of two representative allelic products of the maj or piroplasm surface protein (MPSP) of Theileria sergenti were studied . Sera from cattle infected with either of Ikeda and Chitose types of the parasite reacted strongly with homologous but weakly with heterolo gous recombinant antigens in immunoblotting. Monoclonal antibodies (Mo Abs) produced against the both allelic products of MPSP parasites reac ted only to the immunizing antigen. These results suggested that cross reactivity between two allelic products is very low inspite of relativ ely high homology in their amino acid sequences. Double staining of pa rasitized erythrocyte smear using type-specific MoAbs by an indirect i mmunofluorescent assay revealed that the set of MoAbs was useful for q uantitative and differential detection of each type of parasite in mix ed population.