Microsatellite genotyping of Trypanosoma brucei rhodesiense strains from Uganda that differ in pathology form distinct clusters that correlate with phenotype

Abstract

44 Trypanosoma brucei rhodesiense strains, isolated from humans at eight sites in Uganda between 1988-1992, have exhibited two distinct clinical forms. Isoenzyme analysis has linked this apparent difference in virulence to different zymodemes, the phenotypes of which have been replicated in mice. Using 6 microsatellite markers, 36 of these samples have been genotyped and the results compared to those from a previously published study (Maclean et al 2007). Although the genotypes cluster by clinical phenotype in both studies, the strains from the two studies do not cluster together. This is consistent with the hypothesis that there may be genetic differences in the parasites that are associated with differences in clinical phenotype. The presence of multiple clusters of less and more virulent parasites suggests there may have been gene flow between parasite populations or multiple origins of the virulence phenotypes