Combined Vibrio and nanoplastics stress promotes nanoplastic accumulation while reducing bacterial lethality in shrimp

Nanoplastics (NPs) and pathogenic bacteria are widely present in natural water, yet their interactive effects on aquatic organisms remain poorly understood. In this study, we demonstrate for the first time that Vibrio parahaemolyticus can extensively capture free NPs and facilitate their translocation through the intestinal barrier of Litopenaeus vannamei, thereby altering the distribution of NPs within shrimp and exacerbating their accumulation in the hepatopancreas. These findings provide the first evidence that bacteria act as carriers of NPs influencing their translocation. Interestingly, NPs also affect V. parahaemolyticus infection in shrimp by attenuating the virulence of pathogen, as evidenced by downregulated expression of virulence genes (Tdh and Trh), reduced bacterial loads, and improved host survival rates. Single-cell transcriptomics analysis revealed that NPs activate both energy metabolism and immune pathways, collectively enhancing the host's antioxidative capacity and immunocompetence. These findings offer novel insights into the mechanisms of NPs-pathogen-host interactions and provide critical data for assessing the ecological risks of plastic pollution to seafood safety.