Determination of antigen b (agb) gene polymorphism in cattle and sheep isolates of echinococcus granulosus and investigation of its effectiveness on serological diagnosis

Cystic Echinococcosis (CE) is a worldwide common of helminth disease caused by the larval form of Echinococcus granulosus. Antigen B (AgB) is an excretory-secretory product of E. granulosus larvae, which is secreted in abundance by the larval form of parasite and is used as antigen source for the serological diagnosis of CE. AgB is encoded by a multigen family, and it is suggested that there are also tasks related to escape from the host immunity system. The aim of this thesis is to determine the genetic difference between the different isolates of E. granulosus obtained from cattle and sheep and to detect the polymorphism in AgB1 gene by DNA sequence analysis and to investigate the relationship with serological response using ELISA and Western Blot test. For this purpose, the germinal membranes of hydatic cysts belong to 30 cattle and 30 sheep of each from Elazığ and Erzincan provinces and blood serum samples of these animals were collected. After the isolation of total genomic DNA, 12S rRNA of all isolates was amplified by the PCR method for genetic characterization, and mt-CO1 gene region of the samples which can not obtain bands was analyzed by DNA sequence analysis. Subsequently, gDNAs were amplified with PCR using AgB1 specific primers and genetic variation was investigated by sequence analysis. At the last step, all sera samples were analyzed by ELISA and Western Blot tests using partially purified cyst fluid antigen. As a result 114 (95%) of the total 120 isolates were identified as 12S rRNA-PZR, 6 isolates were identified as mt-COl-PCR and DNA sequencing that all of them were E. granulosus sensu stricto. Following DNA sequencing, nucleotide changes in the AgB1 gene were determined in 13 (10.8%) of the 120 samples. In this study, 9 (69.2%) of the 13 hydatid cysts with polymorphism in the AgB1 gene using DNA sequencing were found to be positive with ELISA and 6 (46.1%) by WB. On the other hand, 80 (74.7%) of the 107 cases with no polymorphism in the AgB1 gene were found positive by ELISA and 75 (70.9%) with WB. As a conclusion, variation was found in the AgB1 gene of E. granulosus sensu stricto at various ratios and it was determined that it had a partial effect on the serological response.