Abstract
Gnathostomiasis is a prevalent zoonosis in humans in some regions of the world. The genus Gnathostoma is considered an accidental parasite for humans; G. binucleatum is the endemic species in Nayarit, Mexico. This work was designed to determine the proteolytic activity of the excretory-secretory products (ESP) of advanced third-stage larvae (ADVL3) of Gnathostoma binucleatum against human fibronectin and antibodies from human and sheep. Our findings showed protease activity against human fibronectin as well as sheep and human gamma globulins of the ESP at molecular weights of 80 and 56 kDa. The proteases found in the ESP of G. binucleatum are thus candidate molecules for consideration as pathogenic elements, owing to the fact that they destroy proteins of the host tissue, which probably allows them to migrate through those tissues and degrade molecules involved in the humoral immune response.