Unstable laboratory Wolbachia strain w-Anga is negatively correlated with Plasmodium falciparum in wild malaria vectors.

Spread of insecticides resistance threatens the control of malaria. In this context, biological control using an endosymbiotic bacterium Wolbachia is being explored as a complementary method for its control. However, for optimal use of this bacterium in biocontrol strategies, it is imperative to characterize it. So, Anopheles gambiae complex mosquitoes were collected, morphologically identified, then blood fed and gravid female mosquitoes oviposited individually. After oviposition, the species of parent was molecularly determined, along with their w-Anga infection status. Additionally, we performed 16SrRNA gene sequencing of w-Anga-positive mosquitoes to determine their phylogeny. Finally, we amplified gene encoding the circumsporozoite protein to determinate their Plasmodium falciparum infection status and assessed the stability of w-Anga transmission of positive females and their offspring. From the results obtained, our w-Anga strains cluster with other Wolbachia Supergroup B strains. However, the prevalence of Plasmodium falciparum infection was lower in Wolbachia-infected females (4.59%) than in those uninfected (22.02%). Furthermore, the transmission frequency of this bacterium in infected Anopheles coluzzii females of the F0 generation to F1 offspring was 10.64% and 16.67% from infected females of the F1 generation to F2 offspring. This study results will serve as preliminary data for the possible use of Wolbachia in malaria control.