A potential diagnostic reagent for bovine cysticercosis.

A fraction of larval Taenia hydatigena cyst fluid was shown to have high sensitivity and specificity in the enzyme-linked immunosorbent assay (ELISA) for the detection of bovine antibodies to the heterologous parasite Taenia saginata. This antigenically active lipoprotein fraction was isolated by ultracentrifugal density flotation using either ammonium sulfate (specific gravity = 1.231 g per ml) or NaCl/KBr (specific gravity = 1.225 g per ml), followed by ion-exchange chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated that this fraction was composed of high molecular weight (65,000 to 77,000 Mr) and low molecular weight (9,500 to 16,000 Mr) proteins. Electrophoresis under non-denaturing conditions in either acrylamide (5%) or agarose (1%) resulted in 1 major diffuse band staining for both protein and lipid. The high and low molecular weight proteins observed on SDS-PAGE under reducing conditions could not be resolved by gel filtration chromatography and emerged as a single lipoprotein peak. This T. hydatigena cyst fluid fraction appears promising as a diagnostic reagent in the ELISA for bovine cysticercosis.