ITS microbial communities composition of Ae. albopictus colonized and uncolonized waters

The Asian tiger mosquito Aedes albopictus is well adapted to urban environment and takes advantage of the artificial containers that proliferate in anthropized landscapes. These artificial water reservoirs, where the larvae develop, are influenced by biotic and abiotic factors that can impact the life cycle of mosquitoes and therefore the presence of the larvae. Little is known about the physicochemical, pollutant and microbiota composition of Ae. albopictus colonized and uncolonized waters. We specifically addressed this question in French community gardens by investigating whether pollution gradients (characterized either by water physicochemical properties combined with pollution variables or presence of organic molecules in water) influence water microbial composition and then the presence / absence of Ae. albopictus mosquitoes. In addition, we tried to estimate whether physicochemical composition of the larval habitat and presence of pollutants are correlated with its microbial composition. To that end, we used high throughput sequencing to characterize the composition and diversity of bacterial and micro-eukaryotic communities in water as well as in larvae. Water quality was determined through the characterization of many physicochemical variables such as temperature, pH, salinity, oxygen dissolved, oxidation-reduction potential, total organic compound as well as the ionic and gas composition and organic molecule occurrence. Interestingly, the physicochemical and microbial composition of uncolonized and colonized water samples did not significantly differ, with the exception of N2O and CH4 concentrations that were higher in uncolonized water samples. Moreover, the microbial composition of larval habitats covaried differentially with the pollution gradients according to the colonization status. In water colonized samples, industrial pollution and ionic composition were correlated with microbial OTUs belonging to the genus Actinomycetospora and the phylum Rozellomycota while the presence of organic molecules was correlated with OTUs belonging to the family Rhizobiaceae and the phytopathogenic fungi Ascochyta phaca. Interestinlgy, the phylum Rozellomycota was also correlated with the organic molecule gradient in uncolonized water samples same as the fungal species Neochloris aquatica. This study is the first to report an exhaustive characterization of Ae. albopictus larval habitats in urban environments. Our findings suggest a correlation between pollution gradients and microbial composition according to the water colonization status. Further studies are needed to determine how biotic and abiotic interactions determine the most productive breeding sites for Ae. albopictus and may have carry-over effects on adult life history traits and vector competence.