CELL-SURFACE CARBOHYDRATES IN TRITRICHOMONAS-FOETUS

The cell surface of T. foetus was characterized by using 18 highly purified lectins with specificities for N-acetyl glucosamine, N-acetyl galactosamine, galactose, mannose and sialic acid. The specificity of the lectin-induced cell agglutination was verified by inhibition of the agglutination with the specific sugars. By using cytochemical techniques associated with EM, carbohydrates were detected on the cell surface of T. foetus. The following techniques were used: periodic acid-thiosemicarbazide-silver proteinate, concanavalin A-horseradish peroxidase and ruthenium red. Anionic sites were detected on the cell surface of the protozoan at pH 1.8 and 7.2 with the use of colloidal iron hydroxide and cationized ferritin particles, respectively. The binding of colloidal iron particles, and the agglutination induced by the lectin from Limulus polyphemus, indicated the presence of sialic acid on the cell surface of T. foetus.