Leishmaniasis is a tropical disease caused by protozoan parasites of the genus Leishmania. In Colombia, this disease represents a serious public health problem due to the high number of cases reported annually, the number of species found and the appearance of resistant strains, mainly compared to first-line drugs: N-methyl glucamine antimoniato (Glucantime®) . So far, several studies using next generation sequencing and tools based on “omicas” have provided crucial information regarding the resistance and adaptation mechanisms used by these parasites against antimonials. However, this knowledge in Leishmania species of the new world is scarce, as well as studies that allow to describe the intra-specific genomic architecture in these species. Taking into account the above, this study evaluated the genomic and transcriptomic behavior of the main Leishmania species that circulate in Colombia under the pressure of N-methyl glucamine (Glucantime® (SbIII), as well as the genomic architecture of these species, obtained at from clinical isolates. The results of this thesis allowed us to describe that (i) the distribution of Leishmania species at urban / jungle level is different, (ii) genomic and transcriptomic changes in response to trivalent antimonials is a characteristic shared between species of the old and of the new world and (iii) describe the low structural variation found in Leishmania braziliensis and Leishmania panamensis. Finally, we consider that additional studies are necessary in order to continue expanding the knowledge about the adaptation mechanisms of this parasite.
