Fitness compatibility and dengue virus Inhibition in a Bangladeshi strain of Aedes aegypti infected with the Wolbachia strain wAlbB

Abstract

Abstract Dengue cases in Bangladesh have surged in recent years. The existing insecticide-based control program is challenged by issues of insufficient household coverage and high levels of insecticide resistance in the primary dengue virus (DENV) vector, Aedes aegypti. A more sustainable, effective alternative could be the implementation of a Wolbachia-mediated disease management strategy. Hence, we created and characterised a Wolbachia-infected Ae. aegypti strain with a Dhaka wild-type genetic background, and compared its reproductive compatibility, maternal inheritance, fitness, and virus-blocking ability to the parental strains (Dhaka wild-type and wAlbB2-F4). The new Ae. aegypti strain wAlbB2-Dhaka demonstrated complete cytoplasmic incompatibility with the wild-type and complete maternal transmission, retaining levels of pyrethroid resistance of the Dhaka wild-type. No significant fitness costs were detected during laboratory comparison. Compared to the wild-type, wAlbB2-Dhaka mosquitoes demonstrated a significantly reduced genome copies of DENV in the bodies (44.4%, p = 0.0034); a two-fold reduction in dissemination to legs and wings (47.6%, p 13-fold reduction of DENV in saliva expectorates (proxy of transmission potential) (92.7%, p < 0.0001) 14 days after ingesting dengue-infected blood. Our work indicates that the wAlbB2-Dhaka strain could be used for Ae. aegypti suppression or replacement strategies for dengue management in Bangladesh.

Keywords

• Aedes aegypti
• Wolbachia
• Dengue virus
• Fitness
• Virus blocking