Studies on the pig parasite trypanosoma (nannomonas) simiae

Abstract

The pig parasite Trypanosoma (Nannomonas)simiae is morphologically indistinguishable from Trypanosoma (Nannomonas) congolense: The main distinction between the two species 'is that in the domestic pig the former causes a highly virulent and rapidly fatal disease while the latter causes a more chronic disease. It is not clear whether the two parasites are distinct species, or subspecies or strains of one species. The main aim of the study was to help establish the identity of Trypanosoma (~.) simiae using biochemical and immunological techniques. Isoenzyme pattern analysis using thin-layer starch gel electrophoresis of the enzymes malate dehydrogenase (MDH), phosphoglucoisomerase (PGI), alanine aminotransferase (ALAT) , aspartate aminotransferase (ASAT), phosphoglucomutase (PG4) , malic enzyme ~1E), peptidase I (PEPI) and peptidase II (PEP II), has been carried out on isolates of 1:.. congolense and T, simi.ae, The results show that T. simiae is distinct from its close'relative 1:.. congolense. However, intraspecific variations in some enzymes were found among isolates of T. simiae. Antigenic variation has been investigate? in an isolate of I. simiae using two serological techniques, namely agglutination and lysis. Results obtained from these studies have Sh01VIlthe occurrence of antigenic variation in T. (~.) simiae. In crossreaction experiments,I. simiae did not agglutinate in 1:.. Gongolense antisera. Similarly 1:.. congolense did not agglutinate in T. simiae antisera. The results suggest that these two parasites are antigenically distinct from each other. The end-products of carbohydrate metabolism have been investigated and enzyme assays of trypanosome homogenates carried out. Results from these experiments strongly sugg~st that glycolysis is as important in,I. simiae as it is in other trypanosome species. The major end-products of aerobic glucose metabolism were acetate and pyruvate. Succinate, glycerol and glycerol-phosphate were also present. These results suggest that these organisms have a partial Tri-carboxylic acid cycle (TCA) or an alternative pathway with TCA-cycle intermediates as the end-products. The enzymes hexokinase (HK), pyruvate kinase (PK) and phosphoglucoisomerase (PGI) had the highest levels whereas lactate dehydrogenase (LDH) was present in trace amounts.