Molecular detection and phylogenetic analyses of Arsenophonus endosymbiont in wild specimens of phlebotomine sand flies from Colombia

Endosymbionts have gained prominence as a potential tool for biological control strategies in reducing vector-borne diseases. This study aimed to evaluate the presence of Arsenophonus, Spiroplasma, and Rickettsia endosymbionts in wild specimens of phlebotomine sand flies, as well as in culicids collected in different regions of Colombia. Analyses were conducted through conventional PCR, Sanger sequencing of the 16S rRNA gene, and phylogenetic analyses. Individuals from among 946 phlebotomine sand flies and 143 mosquitoes were selected for taxonomic identification confirmed through the analysis of the cytochrome oxidase subunit I gene sequences. Results showed the presence of Arsenophonus bacteria in samples of Lutzomyia longipalpis, Psychodopygus panamensis, and Pintomyia evansi. Arsenophonus sequences associated with Lu. longipalpis and Ps. panamensis are phylogenetically located near to sequences of louse flies, with K2P genetic distances of 0.006. In contrast, sequences obtained from Pi. evansi are phylogenetically located near Arsenophonus nasoniae (K2P 0.001–0.014). Other sequences of endosymbionts similar to Arsenophonus with high K2P genetic distances (0.056–0.097), when compared to different reference strains of this endosymbiont, were also found in other samples of Lu. longipalpis and Ae. aegypti. To the best of our knowledge, this is the first successful attempt to detect and elucidate the phylogenetic relationship of Arsenophonus in phlebotomine sand flies, yet its role within these insect vectors remains to be fully determined; therefore, the importance of entomological surveys that help better understand its behavior and potential use as a control agent is required to enable the proactive reduction of sand fly populations.