Developing Wolbachia-based disease interventions for an extreme environment

Abstract

Aedes aegyptimosquitoes carrying self-spreading, virus-blockingWolbachiabacteria are being deployed to suppress dengue transmission. However, there are challenges in applying this technology in extreme environments. We introduced twoWolbachiastrains intoAe.aegyptifrom Saudi Arabia for a release program in the hot coastal city of Jeddah.Wolbachiareduced infection and dissemination of dengue virus (DENV2) in Saudi Arabian mosquitoes and showed complete maternal transmission and cytoplasmic incompatibility.Wolbachiareduced egg hatch under a range of environmental conditions, with theWolbachiastrains showing differential thermal stability.Wolbachiaeffects were similar across mosquito genetic backgrounds but we found evidence of local adaptation, with Saudi Arabian mosquitoes having lower egg viability but higher adult desiccation tolerance than Australian mosquitoes. Genetic background effects will influenceWolbachiainvasion dynamics, reinforcing the need to use local genotypes for mosquito release programs, particularly in extreme environments like Jeddah. Our comprehensive characterization ofWolbachiastrains provides a foundation forWolbachia-based disease interventions in harsh climates.