ABSTRACT
Antigenicity of the tegumental extract, excretory-secretory products and the whole somatic extract of Fasciola gigantica were evaluated to detect the most sensitive and specific antigen out of them that could be used as an immuno-diagnostic tool. Scanning electron microscopic study was carried out to have a full picture about the tegumental structure. The immunohistochemical staining technique was done using the indirect immunoperoxidase method on F. gigantica sections before and after removal of the tegument to recognize the most antigenic parts by using patients sera. Counter immunoelectrophoresis was carried out by using sera from patients with fascioliasis (positive control), patients with schistosomiasis and healthy individuals (control group). In addition, antibody response against the three types of antigens was detected as ELISA absorbance readings. The results revealed that antigens of F. gigantica that cause antibody formation in hosts are those generated and released mainly from the tegument. They were the most sensitive and specific.
