Distribution of ovine hydatid disease in Elazığ district and investigations on the antigenetic features of fluids of hydatid cysts from sheep

2. ABSTRACT This study was undertaken to investigate antigenic characteristics of hydatid cyst fluid in sheep by SDS-PAGE method, to evaluate sensitivity and specifity of ELISA and Western blot methods for diagnosis of sheep hydatidosis, and to determine sero-prevalance of hydatidosis in sheep population in Elazığ. Blood samples were collected from 50 sheep with hydatid cysts and 50 sheep with no hydatid cysts at slaughter. These sheep were pursued during the dressing and evisceration procedures for organoleptic inspection. Organs detected with cysts during carcass inspection and stool samples from each animal were collected for parasitological examination. In addition, 50 blood samples were collected from sheep in each of Elazığ Central, Baskil, Keban, Sivrice and Kovancılar. Results revealed that hepato-pulmonar hydatidosis (52%) was the most common form in the infected sheep followed by hepatic cysts (38%) and pulmonary cysts (10%). Further characterization of the cysts indicated that 57% were fertile, 16% were sterile, 2% were calcified, and 26% were under growth. It was determined that fertility rate of cysts were 14.3%, 48%, and 83.3%, in 1, 2, and 3 years old sheep indicating that fertilization rate increase by the age of sheep. Cysts detected during postmortem inspection of 100 sheep carcasses were identified and distributed as Moniezia spp. (20%), Cysticercus tenuicollis (19%), both Hydatid cyst and C. tenuicollis (11%), both Hydatid cyst and Moniezia spp. (7%), and both C. tenuicollis and Moniezia spp. (1%). SDS-PAGE analysis of hydatid cyst fluids indicated that 6 specific-protein bands were detected at molecular weights of 29, 45, 58, 68, 98 and 1 16 kDa. Western blot analysis showed presence of 29, 38, 42, 58, 62, 68, 98, 116, 120, 150 and 205 kDa bands in positive sheep sera, while 38, 58, 62, 68, 116 and 205 kDa bands were4 detected in negative sheep sera. Therefore, it was concluded that the 116 kDa band was specific for diagnosis of hydatid cysts by Western blot analysis of cyst fluid collected from sheep liver. Sensitivity and specifity of Western blotting test were determined as 88% and 84%, respectively, whereas corresponding rates for ELISA were 60% and 94%, respectively. Sensitivity of ELISA was 47.3% in hepatic cysts, 60% in pulmonary cysts, 69.2%o in hepato-pulmonar cysts. Sensitivity ratios of ELISA were 67.8%, 75%, and 38.4% for fertile, sterile, and under-growth cysts, respectively. Sensitivity of Western blot was found 84.2%) in hepatic cysts, 80% in pulmonary cysts, and 92.3% in hepato-pulmonar cysts. Corresponding ratios for sensitivity of Western blot for fertile, sterile, calcified, and under growth cysts were 92.8%, 75%, 100%, and 84.6%, respectively. In conclusion, sero-prevalance of hydatidosis in sheep was found as 62% by ELISA and 66.4% by Western blotting in Elazığ, and sero-prevalance increased by age. Key Words: Hydatid cyst, Sheep, SDS-PAGE, Western blotting, ELISA, Sensitivity, Specifity, Seroprevalance