Wolbachia parasite superinfection: a new tool to fight arbovirus transmission by Aedes aegypti mosquitoes
Aedes aegypti mosquitoes transmit a number of pathogens, including the Dengue, Chikungunya, and Zika viruses. Wolbachia, a bacterium that naturally infects many insect species but not Aedes aegypti, can nonetheless be introduced into the Aedes aegypti population and then block virus replication in the infected mosquito host. As with any antiviral strategy, the potential development of resistance by the virus is a concern. A study published in PLOS Pathogens reports on a strategy to make it harder for Dengue (and possibly other viruses) to develop Wolbachia resistance.
Wolbachia are vertically transmitted by female mosquitoes to their offspring, and a phenomenon called “cytoplasmic incompatibility” gives infected females a reproductive advantage: they can mate and produce viable (and infected) offspring with infected or uninfected males, whereas the cross between uninfected females and infected males doesn’t produce progeny. Over time, these mating outcomes facilitate the replacement of a local, native Aedes aegypti population by a Wolbachia-carrying mosquito population – and recent field trials in five countries have confirmed this to be the case. Because the infected mosquitoes are resistant to being infected by Dengue, Chikungunya and probably Zika virus, this approach should reduce the number of human cases over time and potentially lead to local elimination of these arboviruses.
A. aegypti, blood feeding
Image Credit: Cameron P. Simmons