Some Biological and Immunological Studies on Hydatidosis/Echinococcosis in Egypt
Hydatidosis or echinococcosis is caused by a tapeworm, Echinococcus granulosus. It is still a serious public health of zoonotic and economic importance. The biological identification showed several aspects between the adult worms. The prepatent period was 55 days for camel strain while that of Equine strain was 70 days. Marked differences between the total length of worm; the length and width of scolex, immature, mature and gravid segments; total length and blade length of rostellar hooks were observed. Regarding the immunological studies, the hydatid fluid (HF) and protoscoleces (P) antigens from both animals were partially purified using gel filtration chromatography. The crude and partially purified antigens of HF and P of both origins were resolved by SDS-PAGE. Electrophoretic pattern revealed distinct variations among the used antigens. ELISA was preformed twice to evaluate the crude and partially purified antigens against their sera. The second ELISA was preformed on PC p1 and HFD p2 antigens against sera obtained from naturally infected animals with hydatidosis or with other parasites. The sensitivity of ELISA was 100% using PC p1 and HFD p2 in serodiagnosis of hydatidosis. The specificity of ELISA was 97.6% and 95.9% in both origins, respectively. Using of HFC p1 and HFD p1 antigens in the first step of ELISA showed that these antigens might contain diagnostic epitops for hydatidosis in both origins, so both antigens could be used in Immunoblot technique to identify the diagnostic bands for each species. Western blot recognized two bands at 80 and 150 KDa which might be diagnostic bands in both intermediate hosts. While the epitopes at 21 and 59 KDa might be specific for camel hydatidosis. The common reactive band at the level of 138 KDa might be specific for hydatidosis in donkeys. Two variant subspecies from E. granulosus were recorded. Identification of specific antigens may have a value in diagnosis and vaccine candidates.