Taxonomic, molecular and ecological approach reveals high diversity of vector sand flies, varied blood source supply and a high detection rate of Leishmania DNA in Colombian Amazon region.

Abstract

Background: The Amazon region is home to more than 30% of the sand flies species in Colombia, including vectors of Leishmania mainly in the genus Lutzomyia and Psychodopygus. Advances in morphological and molecular taxonomy of sand flies facilitate the development of updated and robust species inventories in understudied areas, such as the departments of Amazonas and Caquetá. Currently, integrating the detection of blood meal sources and Leishmania DNA represents a key approach under the "One Health" concept by providing insights into human and animal health and the dynamics of different ecosystems.

Methodology/principal findings: This study characterized the sand flies fauna in Amazonas and Caquetá using an integrative taxonomic approach that included DNA detection from blood meal and Leishmania sources. Sand flies were collected using CDC, Shannon, Prokopack traps and mouth aspirators. DNA was analyzed by conventional PCR targeting COI, Cytb, 12S rDNA and HSP-70N markers, respectively. A total of 1,104 specimens were collected, representing 12 genera and 30 species, 10 are recognized vectors of Leishmania, including Nyssomyia antunesi and Psychodopygus amazonensis. Our findings include new reports of regional distribution, particularly the first report of Sciopemyia fluviatilis in Colombia. Homo sapiens (28.8% Cytb; 18.6% 12S) and Sus scrofa (16.9% Cytb; 6.8% 12S) were the main food sources detected. While Nyssomyia fraihai (2.6%), Trichophoromyia cellulana (1.3%), Nyssomyia yuilli pajoti (1.3%) and Evandromyia (Aldamyia) walkeri (1.0%) grouped the highest detection rate of Leishmania DNA (9.0%).

Conclusions/significance: The integration of molecular tools for the confirmation of phlebotomine species allowed the resolution of taxonomic conflicts, especially in the genus Trichophoromyia. These findings provide key information on ecological interactions (vectors-ingesta-Leishmania) related to leishmaniasis in the Colombian Amazon, suggesting a high diversity of sand flies and a significant zoonotic potential.