The wMel Strain of Wolbachia Reduces Transmission of Chikungunya Virus in Aedes aegypti

Abstract

BackgroundNew approaches to preventing chikungunya virus (CHIKV) are needed because current methods are limited to controlling mosquito populations, and they have not prevented the invasion of this virus into new locales, nor have they been sufficient to control the virus upon arrival. A promising candidate for arbovirus control and prevention relies on the introduction of the intracellular bacterium Wolbachia into Aedes aegypti mosquitoes. This primarily has been proposed as a tool to control dengue virus (DENV) transmission; however, evidence suggests Wolbachia infections confer protection for Ae. aegypti against CHIKV. Although this approach holds much promise for limiting virus transmission, at present our understanding of the ability of CHIKV to infect, disseminate, and be transmitted by wMel-infected Ae. aegypti currently being used at Wolbachia release sites is limited.Methodology/Principal FindingsUsing Ae. aegypti infected with the wMel strain of Wolbachia that are being released in Medellin, Colombia, we report that these mosquitoes have reduced vector competence for CHIKV, even with extremely high viral titers in the bloodmeal. In addition, we examined the dynamics of CHIKV infection over the course of four to seven days post feeding. Wolbachia-infected mosquitoes remained non-infective over the duration of seven days, i.e., no infectious virus was detected in the saliva when exposed to bloodmeals of moderate viremia, but CHIKV-exposed, wild type mosquitoes did have viral loads in the saliva consistent with what has been reported elsewhere. Finally, the presence of wMel infection had no impact on the lifespan of mosquitoes as compared to wild type mosquitoes following CHIKV infection.Conclusions/SignificanceThese results could have an impact on vector control strategies in areas where Ae. aegypti are transmitting both DENV and CHIKV; i.e., they argue for further exploration, both in the laboratory and the field, on the feasibility of expanding this technology beyond DENV.

Variation inAedes aegyptiMosquito Competence for Zika Virus Transmission

“…Although some previous studies ( 15 ) showed relatively low Zika virus competence in Ae. aegypti mosquitoes, raising questions about the role of other potential vectors, others have shown this species to be highly competent ( 24 , 25 ). We demonstrated that Ae.…”

Biological Control of Mosquito Vectors: Past, Present, and Future

“…Finally, Wolbachia -infected Ae. aegypti could also play a role in reducing transmission of other mosquito-borne diseases, as Wolbachia inhibits the transmission of chikungunya virus (CHIKV) [112,116], yellow fever virus (YFV) [117], malaria parasites [118,119], and Zika virus (ZIKV) [120]. Given the recent outbreaks of ZIKV in South America, novel control strategies including Wolbachia should be considered if Ae.…”

Variable Inhibition of Zika Virus Replication by Different Wolbachia Strains in Mosquito Cell Cultures

“…Nevertheless, introduction of wMel into the Aedes mosquito host (10,16,18) also limits DENV (10,19,20), ZIKV (21,22), and CHIKV (23) infections. wMel's lower density causes a limited reduction in fitness of the Aedes host, but the strain is less effective at reducing viral titers than wMelPop (10,15,16,18).…”