Identification and characterization of a 64‒66 kDa antigenic protein of Haemonchus contortus

A protein of 64-66kDa initially identified in the ES products of H. contortus was purified from the adult parasites. This protein appears to be a natural antigen as antibodies against the protein were present in the sera of infected animals. There was a positive correlation of the antibody titer of the protein and the worm burden. Absence of this protein in the infective larvae suggest a role for this protein in the parasitic stage of the organism. Biochemical analyses show that the protein differ from albumin and thus may be of parasite origin.