DETECTION OF HAEMONCHUS-CONTORTUS SURFACE-ANTIGEN IN FECES FROM INFECTED SHEEP

An antigen capture enzyme-linked immosorbent assay (ELISA) has been de veloped that could identify Haemonchus contortus antigens in dilute su spensions of worm homogenates and in faeces from sheep naturally infec ted with moderate burdens of the parasite. The ELISA is based on a pol yclonal (rabbit or sheep) antibody coated solid-phase that captures pa rasite antigen from a suspension of worms or faeces. The captured anti gen is detected by a mouse monoclonal antibody (MAb E2) that is reacti ve with a cuticle surface antigen of H. contortus. Binding of MAb E2 w as shown to be specific for H. contortus and the ELISA was able to det ect this antigen in faeces of some infected sheep. Characterisation of the antigen reacting with MAb E2 indicates it to be a collagenase and protease resistant surface protein of H. contortus that under reducin g conditions in SDS-polyacrylamide gel electrophoresis exists as polyp eptides of molecular weight 122, 56 and 49 kDa.