Abstract
The leishmaniases are caused by Leishmania parasites and transmitted through the bites of phlebotomine sand flies. During parasite development inside the vector’s midgut, promastigotes move towards the stomodeal valve, a mechanism that is crucial for transmission. It has been reported that the sugar meal acquired by sand flies during feeding between bloodmeals is essential for the development and migration of parasites. We demonstrated that the distribution of Leishmania mexicana parasites was affected by the sugar meals obtained by the sand flies. Promastigote migration towards the cardia region seems to be only partially based on the stimuli provided by sugar molecules. In the absence of sugars, significant amounts of parasites developed in the hindgut. In addition, sugar meals were important for the survival of sand flies, especially during blood digestion, presumably supporting their energy requirements.
Highlights
Leishmania parasites develop as extracellular forms in the gut of their sand fly vectors and as obligate intracellular forms inside the phagolysosomes of infected macrophages in the vertebrate host
It is believed that the ingestion of sugar by the vector impacts the developing promastigote parasite population. [6,7,8] It was described for different Leishmania species that they secrete glycosidases, enzymes specialised in the digestion of sugars, like alpha-glucosidase, sucrases, invertases, alpha-amylases, and others.[8,9,10,11] For L. mexicana, both invertase and sucrase activity were identified as secreted by promastigotes.[7,10] In this respect, L. mexicana might use sugar meals as an exogenous source of energy for its development
Sugar ingestion by females sand flies creates a sugar gradient along the midgut, and it was reported that this gradient provides the stimulus for parasite migration towards the stomodeal valve region by mechanisms of chemo- and osmotaxis.[12,13,14,15] studies investigating the effects of the sugar meal on parasite migration and development using an in vivo model need to be performed
Summary
Leishmania parasites develop as extracellular forms (promastigotes) in the gut of their sand fly vectors and as obligate intracellular forms (amastigotes) inside the phagolysosomes of infected macrophages in the vertebrate host.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
