Lectin staining of trichostrongylid nematode eggs of sheep: rapid identification of Haemonchus contortus eggs with peanut agglutinin.

The binding of 10 different lectins to the surface of trichostrongylid nematode eggs of sheep were investigated. Osage orange seed agglutinin bound to eggs from Haemonchus contortus, Ostertagia circumcincta and Trichostrongylus colubriformis, jack bean agglutinin to H. contortus and O. circumcincta eggs and peanut agglutinin to H. contortus eggs only. Staining of egg mixtures with fluorescein-labelled peanut agglutinin showed that the lectin correctly identified the percentage of H. contortus eggs present. Identification of eggs by lectin staining correlated well with results from larval differentiation. The findings suggest that peanut agglutinin can be used in routine diagnostic parasitology for the rapid identification of H. contortus eggs.