Enzyme electrophoresis in characterizing the causative organism of Gambian trypanosomiasis

Trypanosoma (Trypanozoon) brucei includes three morphologically identical subspecies which are poorly defined by clinical behaviour; T. b. brucei does not infect man, whereas T. b. rhodesiense causes an acute, and T. b gambiense a chronic, disease. Thirty-three isolates of the complex, each of which had previously been identified on clinical or other criteria, were compared by the electrophoretic patterns of two trypanosomal enzymes, alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT). One particular ALAT pattern clearly segregated a group of human pathogens of which all except one were labelled T. b. gambiense. The exception was labelled T. b. rhodesiense, and in addition three putative T. b. gambiense isolates did not have this pattern; it is suggested that only one presents a serious anomaly. The T. b. gambiense group could also be subdivided by three ASAT patterns which coincided with known groupings based on serological criteria.