Rahnella aquatilis Isolated from Aedes albopictus Impairs Mosquito Reproduction Capacity

<i>Aedes albopictus</i> is one of the most important vectors of Dengue, which poses a serious threat to public health. The bacterial microbiota has an effect on the parameters of mosquitos, such as larval development and fecundity, and it has emerged as a promising field to be explored for novel environmentally friendly control strategies. <i>Rahnella</i> sp. are present in many insects, including <i>Ae. Albopictus</i>, and play a role in bacterial-insect interactions; however, the role of the bacteria in mosquito biology has not yet been characterized. In this study, we characterized the <i>Rahnella</i> isolate RAeA1 obtained from <i>Ae. albopcitus,</i> and its colonization stability in <i>Ae. albopictus</i> was investigated by generating GFP-tagged bacteria. The influences of the bacteria on larval development and mosquito reproductive capacity were evaluated by inoculating RAeA1 in axenic larvae and antibiotic-treated adult mosquitoes, respectively. The results indicated that RAeA1, which is widespread in the field population of <i>Ae. albopictus</i>, can be transmitted directly from the parental strain to the progeny and can rescue axenic larvae developing into adults with a prolonged development time to pupation. RAeA1 inoculation can impair egg production and ovary maturation, as well as reducing the synthesis of ecdysteroids and vitellogenin in <i>Ae. albopictus</i> females. Overall, our results provide a thorough study of bacterium function characterization that will facilitate the development of potential strategies in relation to the design of microbiomes for vector control.