High Diagnostic efficiency of affinity isolated fraction in camel and cattle toxoplasmosis

Toxoplasma gondii is a zoonotic protozoan coccidian parasite of both medical and veterinary importance worldwide. Sero-prevalence of T. gondii infection in camels and cattle using purified antigen isolated from the crude extract of camel T. gondii tachyzoites of local strain is the purpose of the current study. Affinity purification process resulted in isolation of a single specific fraction identified by hyper immune serum of rabbit coupled with CNBr-Sepharose 4B. By SDS-PAGE, the fraction was resolved into three bands of 84, 78 and 65 KDa compared with 12 bands associated with crude extract of 114, 92, 84, 78, 65, 52, 43, 33, 26, 22, 18 and 15 KDa. The isolated fraction showed more diagnostic potency compared with crude extract by enzyme linked immune sorbent assay (ELISA) using two fold serially diluted rabbit hyper immune serum. Serological screening of apparently healthy 60 camels and 94 cattle with the isolated fraction using ELISA revealed higher prevalence of toxoplasmosis in camels (66.7%) than in cattle (46.8%). In immunoblot assay two immuno-reactive components; 84 and 78 KDa of crude extract were recognized by camel naturally infected sera while, only one immunogenic band of 78 KDa was detected in isolated fraction. Naturally infected cattle sera identified two immunogenic bands of 65 and 22 KDa in crude extract. One of them, 65KDa, was identified in the fraction which is probably responsible for its high diagnostic potential. The results of the present work indicated that T. gondii infection is prevalent in cattle and camel, which may be a risk factor for human infection with T. gondii. Also, affinity isolated fraction of T. gondii from Local camel strain tachyzoite proved high diagnostic potency of cattle and camel toxoplasmosis.