Detection of Sarcocystis antigens in the sera of experimentally-infected pigs and mice by an immunoenzymatic assay.
Immunoglobulins raised against Sarcocystis miescheriana and Sarcocystis muris cystozoite antigens were isolated from rabbit immune sera by affinity chromatography (using CNBr-activated Sepharose 4B for antigen immobilization). The specific immunoglobulins were incorporated into double-antibody sandwich immuno-enzymatic assays which were firstly quantitated and then used to detect soluble Sarcocystis antigens in the sera of experimentally-infected pigs and mice. Assays employing immunoglobulins attached to the solid-phase at concentrations of 80 micrograms/ml were capable of detecting homologous soluble cystozoite and sporozoite reference antigens at concentrations as low as 8 micrograms/ml. Circulating antigens were detected both in the presence and absence of acute clinical disease in pigs experimentally-infected with high and low doses of S. miescheriana sporocysts. The antigenemia detected was transitory (occurring from 3-20 days post-inoculation: dpi) and coincided well with the sporozoite and merozoite phases of parasite development. Circulating antigens were also detected during subclinical infections in mice (from 4-49 dpi) following their experimental infection with low doses of S. muris sporocysts. Specific immuno-enzymatic assays for circulating Sarcocystis antigens may therefore prove useful in the clinical diagnosis of acute sarcocystosis.
D000818:Animals; D000918:Antibody Specificity; D000941:Antigens / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D007124:Immunoenzyme Techniques; D007136:Immunoglobulins / Q000276:immunology; D051379:Mice; D012522:Sarcocystis / Q000254:growth & development / Q000276:immunology*; D012523:Sarcocystosis / Q000175:diagnosis / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis*
D000941:Antigens; D007136:Immunoglobulins