ATTACHMENT OF TRYPANOSOMA-CRUZI EPIMASTIGOTES TO HYDROPHOBIC SUBSTRATES AND USE OF THIS PROPERTY TO SEPARATE STAGES AND PROMOTE METACYCLOGENESIS

In vivo, epimastigotes of Trypanosoma cruzi colonize a lipidic superfi cial layer of the rectal cuticle of the vector Triatoma infestans. In vitro, epimastigotes of four cultured strains and one strain from redu viids use a terminal area of the flagellum to attach to a variety of a rtificial hydrophobic substances, such as hydrocarbons and a range of synthetic plastics. Trypomastigotes did not attach to these substrates . Hydrophilic molecules, such as neutral or negatively charged polysac charides, did not facilitate binding. Epimastigotes and trypomastigote s were artificially bound by electrostatic forces to positively charge d chitosan or DEAE-Sephacel over their entire surface. Tween 20 and li pid-binding serum albumin effectively inhibited the hydrophobic attach ment. Based on this hydrophobic interaction of epimastigotes, a new ch romatography technique has been devised to gently separate trypomastig otes from epimastigotes using octacosane-coated beads. Furthermore, th e in vitro transformation of epimastigotes to trypomastigotes was enha nced if epimastigotes were permitted to attach to hydrophobic, wax-coa ted culture vessels.