Native Wolbachia influence bacterial composition in the major vector mosquito Aedes aegypti

Bacterial species that inhabit mosquito microbiota play an essential role in determining vector competence. In addition to critical factors such as host genotype, feeding habit and geography, intracellular endosymbiont Wolbachia pipientis modulates microbial composition considerably. In the present study, we assessed the midgut bacterial diversity of Aedes aegypti mosquitoes that is either naturally carrying Wolbachia (wAegB⁺) or antibiotic cured (wAegB^-) through a culture-independent approach. Towards this, 16S rRNA gene libraries were constructed from midgut bacterial DNA of laboratory-reared larvae and adult female mosquitoes fed with sugar or blood. Among them 33 genera comprising 65 distinct species were identified, where > 75% of bacterial taxa were commonly shared by both groups (wAegB⁺ and wAegB^-), implying a subtle shift in the bacterial composition influenced by Wolbachia. Though the change was mostly restricted to minimally represented species, predominant taxa were observed unaltered except for certain genera. While Serratia sp. was abundant in Wolbachia carrying mosquitoes, Pseudomonas sp. and Acinetobacter sp. were predominant in Wolbachia free mosquitoes. This result demonstrates the influence of Wolbachia that could modulate the colonization of certain resident bacterial taxa through competitive interactions. Overall, this study shed more light on the impact of wAegB in altering the gut microbiota of Ae. aegypti mosquito, which might challenge host fitness and vector competence.