A gut commensal Serratia marcescens inhibits dengue virus infection via prodigiosin-induced autophagy in Aedes albopictus

and pharmacological inhibition of ER stress substantially attenuated PG-mediated viral suppression, confirming the functional link between PG-induced ER stress, autophagy activation, and viral clearance. Our findings elucidate a novel mechanism by which a native mosquito gut symbiont metabolite restricts arboviral infection through activation of the host ER stress-autophagy pathway, providing a mechanistic basis and candidate leads for future transmission-blocking studies.