Exposure of < i > Anopheles < /i >  mosquitoes to trypanosomes reduces reproductive fitness and enhances susceptibility to < i > Plasmodium < /i >

by Constentin Dieme, Natalia Marta Zmarlak, Emma Brito-Fravallo, Christelle Travaill é, Adrien Pain, Floriane Cherrier, Corinne Genève, Estefania Calvo-Alvarez, Michelle M. Riehle, Kenneth D. Vernick, Brice Rotureau, Christian Mitri During a blood meal, femaleAnopheles mosquitoes are potentially exposed to diverse microbes in addition to the malaria parasite,Plasmodium. Human and animal African trypanosomiases are frequently co-endemic with malaria in Africa. It is not known whether exposure ofAnopheles to trypanosomes influences their fitness or ability to transmitPlasmodium. Using cell and molecular biology approaches, we found thatTrypanosoma brucei brucei parasites survive for at least 48h after infectious blood meal in the midgut of the major malaria vector,Anopheles coluzzii before being cleared. This transient survival of trypanosomes in the midgut is correlated with a dysbiosis, an alteration in the abundance of the enteric bacterial flora inAnopheles coluzzii. Using a developmental biology approach, we found that the presence of live trypanosomes in mosquito midguts also reduces their reproductive fitness, as it impairs the viability of laid eggs by affecting their hatching. Furthermore, we found thatAnopheles exposure to trypanosomes enhances their vector competence forPlasmodium, as it increases their infection prevalence. A transcriptomic analysis revealed that expression of only twoAnopheles immune genes are modulated during trypanosome exposure and that the i...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research