Value of Haemonchus longistipes purified antigens in diagnosis of gastro-intestinal nematodes infection in camels.

Fractionated Haemonchus longistipes crude antigen revealed 7 protein fractions at molecular weights of 93, 74, 67, 56, 32, 26 and 16 kDa. The bands at 56, 32 and 26 kDa reacted specifically with H. longistipes hyperimmune sera prepared in rabbit (1:100 dilution) using EITB technique. The eluted concentrated fractions as well as crude worm antigens were used in diagnosis of natural infection of Gastro-Intestinal Nematodes (GIN) only or associated with other parasites in camels using ELISA technique. H. longistipes crude antigen and fraction of 26 kDa induced high sensitivity in diagnosis of infection in animals harboring GIN only (sensitivity was 95-100%), while it was 85.0-93.3% with 32 kDa fraction and 55.5-73.3% with that of 56 kDa using ELISA technique. The two H. longistipes eluted protein fractions of 26 and 32 kDa showed higher sensitivity than their crude antigens in diagnosis of GIN infection mixed with other parasites. While, Protein bands of 26 kDa appeared more sensitive than the other protein bands in detection of anti- H. longistipes antibodies at higher serum dilution. With special superiority for fraction of 26 kDa, in comparison with the other antigens, sharp specificity or sensitivity in diagnosis, could not be achieved in this study especially in case of mixed infection with other parasites, where these animals might be immune-compromised.