ABSTRACT
This chapter is concerned with the proteinases of two groups of anaerobic flagellates. Giardia and many trichomonads are inhabitants of the gastrointestinal tract, although the major interest among the trichomonads is in two species which infect the urogenital tract and cause sexually transmitted diseases. These are the human parasite Trichomonas vaginalis and the cattle parasite Tritrichomonas foetus. The two groups have been included in the same chapter for convenience and this does not imply that their proteinases have been found to share features not encountered among other parasitic protozoa. The trichomonad proteinases have been investigated in greater detail than those of Giardia, but in both groups it has been found that cysteine proteinases predominate.
