Abstract

Cleavage of erythrocyte surface sialic acid (SA) by the sialidase produced by trypanosomes is implicated in the pathogenesis of anaemia in African animal trypanosomiasis (AAT). Sialyltransferase (ST) is believed to mediate the attachment of SA to cell surface glycoproteins and glycolipids of the desialylated erythrocytes. ST activities in Trypanosoma congolense-infected sheep and control group were investigated and their variations in physio-biochemical properties were evaluated. Six (6) apparently healthy Nigerian Yankassa breed of sheep comprising of T. congolense-infected (n=3) and non-infected (n=3) groups were used for the experiment. Parasitaemia and packed cell volume (PCV) were determined daily over a 5-week period. ST from the thyroid gland was isolated and partially purified and the enzyme kinetics was also evaluated. Anaemia (mean PCV= 18.83±0.71%) was observed in the T. congolense-infected sheep when compared with the non-infected control group (mean PCV 39.75±0.35%) and the reduction in mean PCV was significant (P

Key words: Anaemia, Sialic acid, Sialyltransferase, Sheep, Trypanosoma congolense