Abstract
Opisthorchiasis is currently widespread not only in the Republic of Kazakhstan but also in many other countries, making it a significant concern in modern medicine and veterinary science. Accurate diagnosis of this disease is crucial for effective treatment. The specificity of diagnostic tests relies on antigen preparations that contain various antigens. Our research focused on studying antigens of different chemical natures derived from the pathogen Opisthorchis felineus. As a result, we obtained three types of antigens: excretory-secretory (ESA), egg (EA), and somatic (SA). We analyzed their protein composition and identified the number of major proteins as follows: ESA - 21, SA - 20, and EA - 33. Protein fractions with molecular weights of 105 and 250 kDa exhibited immunogenic properties. The immunogenic and antigenic properties of these antigens were confirmed. Mass spectrometry analysis of ESA, which includes 214 secretory proteins from the parasite, allowed us to identify three highly immunogenic proteins: cathepsin F, glutathione transferase, and paramyosin, through immunoprecipitation with specific sera.