Adherence and surface properties of Tritrichomonas mobilensis, an intestinal parasite of the squirrel monkey.

Adherence properties of the potentially enteropathogenic Tritrichomonas mobilensis were studied in vitro. Axenically cultivated trichomonads readily attached to isolated intestinal epithelial cells and mucus of the squirrel monkey. The kinetics and nature of T. mobilensis cytadherence were microscopically evaluated in cell-suspension assay using Chinese hamster ovary (CHO) cells and in microplate hemagglutination assay with human erythrocytes. Adherence of the parasites to target cells was concentration- and time-dependent; it was inhibited by sialic acid (N-acetylneuraminic or N-glycolylneuraminic acid) and sialyllactose. Neither trypsinization of the flagellates nor their exposure to low temperature (4 degrees C) affected their cytadherence capacities. The data indicate the presence of adhesin(s) with lectin properties on T. mobilensis. Agglutination of live protozoa by animal and plant lectins with various carbohydrate-binding specificities as well as the occurrence of an electron-dense cell coat on plasma membrane suggest marked glycosylation of the parasite surface.

Structural analysis of the cytoskeleton of Tritrichomonas foetus.

The cytoskeleton of Tritrichomonas foetus was studied by immunofluorescence microscopy, using anti-actin, anti-filamin, anti-myosin and anti-tubulin monospecific antibodies, and by high voltage electron microscopy of Triton X-100 extracted cells. Actin, filamin and myosin were distributed throughout the cytoplasm of T. foetus. Filamin, however, is more concentrated at the cell periphery. The peltar-axostylar system could be seen in interphasic and dividing cells using anti-tubulin antibodies. High voltage electron micrographs showed the spatial distribution of the microtubules and their association with the hydrogenosomes, and the association of the costa with the recurrent flagellum.

Inhibition of Tritrichomonas foetus by vermiculine in vitro.

The macrolide aglycosidic antibiotic vermiculine, added to the cultivation medium to a concentration of 30 micogram/ml, has an in vitro inhibitory effect on Tritrichomonas foetus. The agent interacts rapidly with the cells, causing irreversible changes after several hours of action. The changes are not repaired on removing the agent; the cells suffer from a rapid inhibition of nucleic acid synthesis, the protein synthesis remaining intact.

Gastrointestinal trichomonads in horses: occurrence and identification.

A survey of horses for gastrointestinal trichomonads was conducted to determine the organism's role in equine diarrhea and to establish its proper identity and morphology. Trichomonads were found by cultural examination of feces of 101 (35%) of 289 apparently healthy horses. At necropsy, trichomonads were cultured from 11 (37%) of another 30 horses which showed no signs of diarrhea at the time of death. In 4 of the 11 horses, colonies of trichomonads numbered 30,000 to 150,000/ml of cecal fluid. Diarrhea was induced in 1 of 6 horses, with the fecal fluid containing 10,000 to 110,000 trichomonads/ml. The trichomonad was identified as Tritrichomonas equi and it appears to be a normal member of the intestinal fauna of the horse. Its role as the etiologic agent of equine diarrhea is considered doubtful. The large numbers of T equi found in diarrheic feces are considered a response to, rather than a cause of, the fluidic environment of the gastrointestinal tract.

Biochemical cytology of trichomonad flagellates. I. Subcellular localization of hydrolases, dehydrogenases, and catalase in Tritrichomonas foetus.

To determine the localization of several enzymes in Tritrichomonas foetus, the axenic KV-1 strain was grown in Diamond's medium with bovine serum, homogenized in 0.25 M sucrose, and subjected to analytical differential and isopycnic centrifugation. The fractions were assayed for their enzymatic composition and examined electron microscopically. NADH and NADPH dehydrogenases, about 90% of the catalase, and two hydrolases, alpha-galactosidase and manganese-activated beta-galactosidase I are in the nonsedimentable part of the cytoplasm. alpha-Glycerophosphate and malate dehydrogenases are associated with a large particle, whose equilibrium density in sucrose gradients is 1.24. This particle corresponds to that population of the paracostal and paraxostylar granules which, having a uniform granular matrix surrounded by a single membrane, resemble microbodies from other organisms. The small sedimentable portion of catalase (about 10% of the total activity) is not associated with these granules and equilibrates at density 1.22. The nature of the subcellular entity carrying catalase could not be ascertained. Hydrolases with a pH optimum around 6-6.5 (protease, beta-N-acetylglucosaminidase, beta-N-acetylgalactosaminidase, and cation-independent beta-galactosidase II), as well as a large part of acid phosphatase, are associated with a population of large particles which equilibrate at densities from 1.15 to 1.20. The hydrolases in these granules lose their structure-bound latency easily after freezing and thawing. These particles correspond to another population of the paracostal and paraxostylar granules which have varied shape and inhomogeneous content with frequent myelin figures, indicating a digestive function. The rest of the phosphatase and most of the acid beta-glucuronidase activity are in a smaller granule fraction with an equilibrium density around 1.18. The latency of these enzymes is quite resistant to freezing and thawing. This particle population consists of smaller, very often flattened vesicles and granules, many of which are clearly fragments of the prominent Golgi apparatus of the cell.