Microbiota variation in Aedes aegypti (Diptera:Culicidae): a comparative study of field-caught and laboratory-adapted reared populations

The control of Aedes aegypti, the main vector of Dengue, Zika, and Chikungunya, remains a global health priority due to its expanding distribution and the absence of specific treatments. The mosquito's microbiota is increasingly recognized as a factor influencing its biology and vector competence; however, studies comparing wild and laboratory-reared populations are scarce, particularly in Colombia. This study examined the bacterial and microeukaryotic microbiota of Ae. aegypti from four municipalities in Boyacá (Puerto Boyacá, Otanche, Moniquirá, and Muzo), alongside laboratory-reared populations maintained for at least five generations and the Rockefeller strain. Microbial profiling was performed using Oxford Nanopore sequencing of 16S and 18S rRNA genes. Results indicated no significant differences in alpha diversity, but beta diversity varied among groups; laboratory-reared mosquitoes showed a higher abundance of Pseudomonas aeruginosa, suggesting environmental selection. Despite these variations, a shared microbiota was identified among all groups, including Cutibacterium acnes, Dechloromonas hortensis, P. aeruginosa, Caldimonas brevitalea, Acinetobacter soli, Chryseobacterium indologenes, and Pseudomonas putida, which hypothetically suggests the possibility of transstadial transmission. Importantly, this study reports for the first time the presence of the parasite Ascogregarina culicis in Ae. aegypti from Colombia, a potential modulator of arbovirus transmission that warrants further attention in future studies. Overall, this work provides the first comparative profile of field-collected, laboratory-adapted, and Rockefeller strain populations of Ae. aegypti from Boyacá, highlighting the influence of environmental conditions on microbial composition. The bacterial repertoire identified offers candidate symbionts for future functional studies and for the development of new vector-control strategies.IMPORTANCEWe report changes in the bacterial and microeukaryotic microbiota of Aedes aegypti collected in the field and subsequently adapted to laboratory conditions for at least five generations. Our study identified shifts in bacterial beta diversity (principal coordinates analysis, ANOSIM, permutational multivariate analysis of variance; P = 0.003), confirming that the rearing environment influences microbial composition. In addition, our findings suggest that certain bacterial microorganisms were associated with both field-collected and laboratory-adapted insects (shared microbiota), which may be relevant to mosquito biology. This study expands our understanding of microbial changes associated with rearing conditions, highlighting their importance for the development of future vector-control strategies.