Yeast symbionts in Phlebotomus perniciosus: possible implications for the control of vector-borne diseases

The control of vector-borne diseases represents one of the greatest global public health challenges of the 21st century. In this context, biological control methods represent an alternative to the use of chemicals, and the use of microorganisms is now well established in biocontrol. While arthropod-associated bacteria are the focus of several research programs aimed at developing strategies to control vector-borne diseases, such as malaria, dengue, and trypanosomiasis, arthropod-associated yeasts and their killer toxins have not yet been deeply investigated. We present our studies, conducted with culture-based and culture independent methods (454 Pyrosequencing, PCR screening, FISH), on the yeast community associated with the sand fly Phlebotomus perniciosus, the main vector of leishmaniases in the western Mediterranean area, with the aim of investigating their potential to interfere with Leishmania development in the insect. As one of the results, we isolated and phylogenetically characterized a strain of the yeast Wickerhamomyces anomalus with killer phenotype from laboratory-reared sand flies. The association between P. perniciosus and yeasts deserves to be further investigated, in order to explore the possibility that this yeast could exert inhibitory/killing activity against Leishmania spp.