Ecological and engineered modulation of the mosquito microbiome: mechanisms, vector competence, and translational...

Malaria, dengue fever, Zika, chikungunya, yellow fever, and West Nile fever are mosquito-borne diseases that collectively impose an enormous global health burden, disproportionately affecting low- and middle-income countries where vector-control tools remain limited or compromised by insecticide resistance. Over the past two decades, the characterization of mosquito-associated microbiomes has transformed our understanding of vector biology, revealing complex, ecologically contingent assemblages of bacteria, fungi, viruses, and protists that profoundly influence mosquito physiology, immunity, and pathogen transmission competence. This review synthesizes current knowledge on the composition and determinants of the mosquito microbiome across major vector genera-Aedes, Anopheles, and Culex-and critically evaluates evidence for microbiome roles in larval development, adult fitness, immune homeostasis, and pathogen-vector interactions. We examine how resident microbiota can inhibit or, in some contexts, facilitate pathogen establishment, dissemination, and transmission, and we discuss the mechanistic pathways underlying these effects, including immune priming, niche competition, antimicrobial metabolite production, and modulation of midgut barrier integrity. We then review major strategies for deliberate microbiome modulation, including Wolbachia-based pathogen blocking and population suppression, paratransgenesis, symbiont supplementation, microbiota engineering, and habitat-level manipulation, and evaluate their biological rationale, current evidence base, field feasibility, and limitations. Attention is given to the gap between laboratory proof-of-concept and operational deployment, as well as to biosafety, regulatory, ecological, and ethical challenges that must be resolved before microbiome-based interventions can be integrated into public health programs. We conclude by identifying priority research questions and the technological advances most likely to accelerate progress from descriptive microbiome science to predictive, actionable vector control.