Identification of phlebotomine sand flies (Diptera: Psychodidae) from leishmaniasis endemic areas in southeastern Mexico using DNA barcoding

Leishmaniasis, a vector-borne disease transmitted to humans through the bite of phlebotomine sand flies, is of public health significance in southeastern Mexico. Active and continuous monitoring of vectors is an important aspect of disease control for the prediction of potential outbreaks. Thus, the correct identification of vectors is paramount in this regard. In this study, we employed DNA barcoding as a tool for identifying phlebotomine sand flies collected in localized cutaneous leishmaniasis endemic areas of Quintana Roo, Mexico. Specimens were collected using CDC light and Shannon traps as part of the Mexican Ministry of Health surveillance program. DNA extraction was carried out using a nondestructive protocol, and morphological identification based on taxonomic keys was conducted on slide-mounted specimens. Molecular taxonomic resolution using the 658-bp fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene was 100% congruent with the morphological identification. Seven species were identified: Lutzomyia cruciata (Coquillett 1907), Lutzomyia longipalpis (Lutz & Neiva 1912), Psathyromyia shannoni (Dyar 1929), Dampfomyia deleoni (Fairchild & Hertig 1947), Dampfomyia beltrani/steatopyga (Vargas & Díaz-Nájera 1951), Bichromomyia olmeca olmeca (Vargas & Díaz-Nájera, 1959), and Brumptomyia mesai (Sherlock 1962). Mean intraspecific divergence ranged from 0.12% to 1.22%, while interspecific distances ranged from 11.59% to 19.29%. Neighbor-joining (NJ) analysis using the Kimura 2-parameter model also showed specimens of the same species to be clustered together. The study provides the first cox1 sequences for three species of sand flies and indicates the utility of DNA barcoding for phlebotomine sand flies species identification in southeastern Mexico.