Bacteria-delivered RNA interference strategies to silence genes related to vector competence of Aedes aegypti

Dengue infection is a devastating mosquito-borne disease, and the principal vector is the mosquito, Aedes aegypti. Current vector control strategies are not working, hence the need for alternative strategies. Cathepsin B is a mosquito protein that dengue viruses require to establish and replicate within mosquitoes; knocking down cathepsin B using RNAi changes the phenotype from dengue susceptible to dengue refractory in Ae. aegypti. We engineered bacteria to express dsRNA against cathepsin B to develop an orally delivered RNAi system. Our data suggest inconsistencies in the alteration of gene expression that may be a result of the modified bacteria being digested, or a lower than required quantity of the RNAi constructs being expressed. Without a consistent knockdown, it is unlikely that we will be able to reduce vector competence predictably.