A study of proteases throughout the life cycle of Trichinella spiralis

In the present report we study the proteolytic activity of the excretion-se cretion and crude extracts of different stages of Trichinella spiralis (Owe n, 1835) Railliet, 1895, (muscle-stage larvae, adult worms before and after mating, and newborn larvae) using natural substrates (structural and hemat ic mammalian proteins). The analysis of the results allow us to set up a ce rtain stage-specificity, as well as an important relationship between the p rotease patterns throughout the parasite life cycle and how the parasite ma y overcome both mechanical and humoral barriers within the host. Muscle-sta ge larvae present a great activity against structural proteins (collagen), while newborn larvae and adult worms degrade principally hematic proteins ( hemoglobin, fibrinogen and immunoglobulin G).