Leishmania, microbiota and sand fly immunity

Abstract

In this review, we explore the state-of-the-art of sand fly relationships with microbiota, viruses and Leishmania, with particular emphasis on the vector immune responses. Insect-borne diseases are a major public health problem in the world. Phlebotomine sand flies are proven vectors of several aetiological agents including viruses, bacteria and the trypanosomatid Leishmania, which are responsible for diseases such as viral encephalitis, bartonellosis and leishmaniasis, respectively. All metazoans in nature coexist intimately with a community of commensal microorganisms known as microbiota. The microbiota has a fundamental role in the induction, maturation and function of the host immune system, which can modulate host protection from pathogens and infectious diseases. We briefly review viruses of public health importance present in sand flies and revisit studies done on bacterial and fungal gut contents of these vectors. We bring this information into the context of sand fly development and immune responses. We highlight the immunity mechanisms that the insect utilizes to survive the potential threats involved in these interactions and discuss the recently discovered complex interactions among microbiota, sand fly, Leishmania and virus. Additionally, some of the alternative control strategies that could benefit from the current knowledge are considered.

Role of plants in the transmission of Asaia sp., which potentially inhibit the Plasmodium sporogenic cycle in Anopheles mosquitoes

“…Plants also provide male mosquitoes with enough energy to successfully fertilize females, thus ensuring species perennity 7 . Mosquitoes are attracted by the odors emitted by plants and use those odors to locate plants that can provide the sugar and/or chemicals they need to survive in their natural environment 6 .Several studies have discussed the importance of arthropod vector microbiota for the prevention of certain vector-borne diseases [8][9][10][11] . The composition of these microbiota is not only influenced by the bacterial flora in breeding sites but also by the sources of adult mosquitoes' diets 12,13 .…”

“…Several studies have discussed the importance of arthropod vector microbiota for the prevention of certain vector-borne diseases [8][9][10][11] . The composition of these microbiota is not only influenced by the bacterial flora in breeding sites but also by the sources of adult mosquitoes' diets 12,13 .…”

Host Species Determines the Composition of the Prokaryotic Microbiota in Phlebotomus Sandflies

“…Rhizobiaceae encompass a range of bacterial genera which are prevalent in soil and plant tissues, hence their presence in insect gut has been associated with plant feeding lifestyles [ 55 , 56 ]. Pseudomonas are common dwellers of the gut of wild caught sandflies [ 4 , 30 , 57 ]. Their common presence in larvae and adults of sandflies was attributed to acquisition by soil during the soil feeding larvae stage [ 37 ].…”

Leishmaniasis: A spectrum of diseases shaped by evolutionary pressures across diverse life cycle

“…1 ). For instance, fitness in the sandfly is influenced by immunologic barriers, microbial competition and insect ecology [ 2 , 3 ]. In vertebrate hosts, fitness is influenced by the immune response, tissue tropism and vertebrate ecology [ 4 ].…”