NewTrypanosoma (Duttonella) vivaxgenotypes from tsetse flies in East Africa

Abstract

SUMMARYSalivarian trypanosomes pose a substantial threat to livestock, but their full diversity is not known. To survey trypanosomes carried by tsetse in Tanzania, DNA samples from infected proboscides ofGlossina pallidipesandG. swynnertoniwere identified using fluorescent fragment length barcoding (FFLB), which discriminates species by size polymorphisms in multiple regions of the ribosomal RNA locus. FFLB identified the trypanosomes in 65 of 105 (61·9%) infected proboscides, revealing 9 mixed infections. Of 7 different FFLB profiles, 2 were similar but not identical to reference West AfricanTrypanosoma vivax; 5 other profiles belonged to known species also identified in fly midguts. Phylogenetic analysis of the glycosomal glyceraldehyde phosphate dehydrogenase gene revealed that the TanzanianT. vivaxsamples fell into 2 distinct groups, both outside the main clade of African and South AmericanT. vivax. These newT. vivaxgenotypes were common and widespread in tsetse in Tanzania. TheT. brucei-like trypanosome previously described from tsetse midguts was also found in 2 proboscides, demonstrating a salivarian transmission route. Investigation of mammalian host range and pathogenicity will reveal the importance of these new trypanosomes for the epidemiology and control of animal trypanosomiasis in East Africa.