The detection of IgM and IgG antibodies against Babesia bigemina in bovine sera using semi-defined antigens in enzyme immunoassays.

Soluble extracts prepared from Babesia bigemina merozoites were tested for antigenicity in class-specific enzyme immunoassays currently being evaluated for the differential serodiagnosis of bovine babesiosis. Intact merozoites were harvested from erythrocytes from an experimentally-infected calf by controlled hypotonic lysis and differential ultra-centrifugation. The merozoites were disrupted by ultrasonication and a crude soluble extract obtained by ultracentrifugation.

Attempted immunization of swine against acute sarcocystosis using cystozoite-derived vaccines.

Low-dose Sarcocystis miescheriana infections have recently been shown to protect pigs against acute sarcocystosis. Because this protective immunity was short-lasting, an alternative immunization strategy was examined. Four experimental vaccines were prepared from S.

Class-specific antibody responses in pigs following immunization and challenge with sporocysts of Sarcocystis miescheriana.

Sixteen pigs were each immunized by oral inoculation with 1000 sporocysts of Sarcocystis miescheriana at 8 weeks of age. Four equal groups were then challenged with 3 million sporocysts per animal at 40, 80, 120 or 160 days post-immunization (dpi). Host antibody responses were monitored using the enzyme-linked immunosorbent assay (ELISA) and the indirect fluorescent-antibody test (IFAT).

Examinations on the serodiagnosis of Sarcocystis infections. II. Class-specific immunoglobulin responses in mice, pigs, and sheep.

Mice, pigs and sheep were experimentally infected with Sarcocystis muris, S. miescheriana (syn. S.

Persistence of acquired immunity to Sarcocystis miescheriana infection in growing pigs.

Sixteen 8-week-old pigs were each experimentally immunized by subclinical infections with 10(3) Sarcocystis miescheriana (syn. S. suicanis) sporocysts and 8 other pigs served as non-immunized controls.

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.