Partial antigen purification of the cattle nematode Cooperia oncophora

Diagnosis of gastrointestinal nematode infections in cattle still remains a problem. Detection of antibodies with an enzyme immuno assay provides little genus specificity when using crude parasite extracts. In an attempt to identify genus specific antigens, Cooperia oncophora third stage larvae (L3) were analysed by SDS-PAGE and Western blotting. For immunodetection sera were used from mono infected C. oncophora and Ostertagia ostertagi calves, sera from naturally infected first year grazing calves and negative sera from helminth free raised animals. Two antigens were recognized which were species specific. A C. oncophora L3 36 kDa antigen was identified by C. oncophora anti serum and a C. oncophora L3 22 kDa antigen was only recognized by O. ostertagi anti serum. The partial purification of both antigens was achieved by ion exchange chromatography on a QAE-Sephadex A-50, followed by gelfiltration on a Sephadex G-75. The possible use of these antigens in the diagnosis of parasitic gastroenteritis in cattle is discussed