Phylogenetic characterization of two common sand flies Phlebotomus major and P. kandelakii in the West Black Sea Region of Turkey based on mitochondrial genes sequence analysis

Abstract

Research on the taxonomy and phylogenetic characterization of sand flies (Diptera, Psychodidae, Phlebotominae) has received increasing attention due to their potential role in the transmission of medically significant diseases, including leishmaniasis, bartonellosis, and sand fly fever. Phlebotomus major and Phlebotomus kandelakii are the members of Larroussius subgenus that includes important vector sand fly species. P. major, P. neglectus and P. syriacus from a well-known sand fly “Major” species group are present widely while P. kandelakii has constricted distribution in Turkey. All have the capability to transmit Leishmania infantum, the causative agent of visceral leishmaniasis. Here, we investigated the genetic diversity within each species collected from the West Black Sea Region of Turkey using mitochondrial DNA markers, specifically cytochrome oxidase I (COI) and cytochrome b gene sequences (Cytb). A total of 1889 sand flies specimens were collected from the study area in June 2021 and August 2022, 1596 (84.49%) were identified as P. major s.l., and 253 (13.40%) were identified as P. kandelakii. Nine and four haplotypes of P. major were determined in the study area based on COI and Cytb sequences, respectively. Analysis of the phylogenetic data sets generated from our isolates and published isolates in Genbank revealed high haplotype diversities within P. major (COI = 0.933, Cytb = 0.714). For P. kandelakii, we detected four and three haplotypes within the COI and Cytb sequences, and the haplotype diversities were also high in the datasets including our isolates and published isolates in Genbank (COI = 0.978, Cytb = 1.000). Pairwise mean genetic distance calculated from the COI and Cytb datasets were 0.4% and 1.4% for P. major, and 1.0% and 0.2% for P. kandelakii, respectively, suggesting the absence of cryptic species. Phylogenetic analyses revealed three and two major clusters of Larroussius subgenus in the COI and Cytb datasets, respectively.