Introduction:

Within the Trypanosomatidae family, there are two genera of medical importance for their role as human pathogens, Trypanosoma and Leishmania. Within these genera are species and subspecies that cause leishmaniasis, American Trypanosomiasis and Human African Trypanosomiasis. Objective. In this study, we investigated the phylogenetic relationships of the genus Leishmania and Trypanosoma using the cytoplasmic hsp70 gene and we discussed the implications for species definitions, evolution and taxonomy of these genera.

Methods:

The hsp70 gene from 44 strains from 11 Leishmania species and 41 strains from 9 Trypanosoma species from different geographical origins were sequenced. The sequences obtained were aligned with the sequences previously published in the databases. The MEGA program was used for the construction of different phylogenetic trees based on distance and character parameters. The support of the monophyletic groups was determined by the "boostrap" method.

Results:

For the first time, the cytoplasmic hsp70 gene was used in phylogenetic studies of the Leishmania and Trypanosoma genus and, with the results obtained, it was demonstrated that it is convenient to use it as a molecular marker for molecular methods design for detection, identification and differentiation of Leishmania and Trypanosoma species and lineages. Evidence is provided that supports the hypothesis that the genus Leishmania originated in South America (“New World”), thus contributing to the general discussion about the origin of this genus. Conclusion: This study actively contributed to discussing the implications of this analysis for the taxonomic framework for the Leishmania and Trypanosoma genera.

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