DNA barcoding to identify species of phlebotomine sand fly (Diptera: Psychodidae) in the mixed leishmaniasis focus of the Colombian Caribbean.

Abstract

Identification of the species of phlebotomine sand flies present in each focus of leishmaniasis is necessary to incriminate vectors and implement vector control strategies. Although the cytochrome oxidase I (COI) gene has been proposed as a barcode for the identification of animal species, less than 20% of New World phlebotomines have been characterized to date. In this study DNA barcoding was used to identify phlebotomine species of the mixed leishmaniasis focus in the Colombian Caribbean by means of three evolutionary models: Kimura's two parameter (K2P) nucleotide substitution model, that of (Tamura and Nei, 1993) (TN93) and proportional sequence divergence (p-distances). A 681bp sequence of the COI gene was obtained from 66 individuals belonging to 19 species of the genus Lutzomyia (Lu. abonnenci, Lu. atroclavata, Lu. bicolor, Lu. carpenteri, Lu. cayennensis cayennensis, Lu. dubitans, Lu. evansi, Lu. gomezi, Lu. gorbitzi, Lu. longipalpis, Lu. micropyga, Lu. migonei, Lu. panamensis, Lu. (Psathyromyia) sp., Lu. rangeliana, Lu. serrana, Lu. shannoni, Lu. trinidadensis and Lu. venezuelensis) and one of Brumptomyia (B. mesai). The genetic divergence values for TN93 among individuals of the same species fluctuated up to 3.2% (vs. 2.9% for K2P and 2.8% for p-distances), while the values between species ranged from 8.8-43.7% (vs. 6.8-19.6% for K2P and 6.6-17.4% for p-distances). A dendrogram constructed by means of the Neighbor-Joining method grouped phlebotomines into 20 clusters according to species, with bootstrap values of up to 100% in those with more than one individual. However, loss of the phylogenetic signal of the gene COI was observed at the supraspecific level as a consequence of substitutional saturation. In conclusion, irrespective of the evolutionary model selected, all phlebotomines were correctly assigned to species, showing 100% concordance with morphological identification.