Tritrichomonas foetus: a scanning electron microscopy study of erythrocyte adhesion associated with hemolytic activity

Abstract

-The in vitro hemolytic activity of Tritrichomonas foetus was investigated. The parasite was tested against human erythrocytes of groups A, B, AB, and O, and against erythrocytes of nine adult animals of different species (the rabbit, rat, chicken, cat, dog, swine, horse, bovine, and sheep). The results showed that T. foetus strains (ATCC KV1, K, PAL, 5022, RJ, 90) did not present any hemolytic activity against any human erythrocyte group nor against rabbit, rat, chicken, cat, dog and swine erythrocytes. T. foetus strains, however, lysed horse, bovine, and sheep erythrocytes. No hemolysin released by the parasites could be identified. Hemolysis did not occur with trichomonad culture supernatants, with sonicated extracts of T. foetus, nor with killed organisms. Scanning electron microscopy (SEM) showed that human erythrocytes did not adhere to the trophozoites, in contrast horse erythrocytes adhered to the surface of the parasites and were phagocytosed for up to 90 min. The parasites are able to exert their cytopathic effects through: (a) physical contact established between the two cell surfaces, (b) toxins released from parasites into the interaction media, or (c) the association of both mechanisms. Further studies are necessary to clarify the importance of the hemolytic activity in the biology of T. foetus.Tritrichomonas foetus / hemolytic activity / scanning electron microscopy / erythrophagocytosis / cytopathic effects

Basic biological aspects of Tritrichomonas foetus of re-levance to the treatment of bovines suffering of tricho-moniasis

“…From a structural viewpoint, it is defined as a cell surce organelle formed by the plasma membrane and exterlly associated carbohydrates. Studies that focus on tricomo-ds-host cell interaction have shown that the cytotoxicity of T. foetus can be triggered from physical contact beeen the surfaces of the parasite and host cell, resulting in the secretion of extracellular proteases and glycosidases [20][21][22]. Such enzymes, in turn, seem not only to induce cytolysis or the disruption of epithelial junctions, but to remodel the surrounding extracellular matrix (ECM) [23].…”