Characterization of surface antigens of Eimeria nieschulzi (Sporozoa, Eimeriidae) merozoites.

Two surface antigens of Eimeria nieschulzi merozoites were characterized by monoclonal antibodies (Mcab) as follows: an antigen of 31 (reducing conditions), 25 and 31 kDa (nonreducing conditions), by Mcab A1F6; and an antigen of 52 and 30 kDa (reducing conditions) or 42 kDa (nonreducing conditions), by Mcab H7. The localization of the antigens in fluorescence and electron micrographs is presented. Despite being accessible to antibodies on live (nonpermeabilized) parasites, neither antigens were significantly labelled using lactoperoxidase radioiodination.