Identification of immunodominant antigens in Mexican strains of Trypanosoma cruzi

Chagas' disease represents an important public health problem. In Mexico mo st studies have been performed using Trypanosoma cruzi' antigens extracted from strains of other geographical origins. This work was aimed at developi ng a reactive antigen to perform serological diagnosis of Chagas' disease, using Mexican T. cruzi strains. We prepared antigenic extracts from epimast igotes, trypomastigotes and sphaeromastigotes of three Mexican strains. Par asites homogenate was obtained by lysis and sonication, solubilized protein s were analyzed by SDS-PAGE, Western-blot assays, and ELISA to determine th e reactivity against sera from chagasic reference serum and chagasic and le ishmaniasic patients and healthy donors. Western Blot profiles revealed, wi th the reference serum, eleven main components between 212 to 25 kDa; howev er, five bands corresponding to 74, 44, 31, 25 and 18 kDa antigens were rec ognized by the T. cruzi reactive sera from Mexican chagasic patients, which did not cross-react with Leishmania mexicana. Antigens from the Tequesquit engo strain yielded the best reactivity in the enzymatic immunoassay, thus enabling us to propose their use for serodiagnoses of Chagas' disease in Me xico.