Spermidine carbon quantum dots as an alternative antimicrobial agent for hatcheries rearing Pacific white shrimp (Litopenaeus vannamei)

Abstract

Bacterial infections often constrain shrimp production in aquaculture systems. This study evaluated the efficacy of a novel antibacterial agent, spermidine carbon quantum dots (spd-CQDs), in promoting the survival of Pacific white shrimp (Litopenaeus vannamei) during the hatching phase and early larval stages. In vitro assessments evaluated the bacteriostatic activity of spd-CQDs against Vibrio strains isolated from shrimp farms in Vietnam and Taiwan. An in vivo challenge was conducted by exposing shrimp larvae to pathogenic Vibrio parahaemolyticus, the causative agent of acute hepatopancreatic necrosis disease (VpAHPND), with or without the inclusion of spd-CQDs in their pellet diet. Results indicate that the application of spd-CQDs significantly reduces Vibrio loads in shrimp hatcheries and enhances larval survival in challenge tests. Further analysis assessed the effects of administering spd-CQDs via live feed for broodstock, powdered feed for larvae, and rearing water. This demonstrated its potential to improve water quality in the aquaculture environment. Overall, spd-CQDs significantly reduced Vibrio loads and improved larval survival, suggesting that spd-CQDs could serve as an alternative to conventional antibiotics, paving the way for more sustainable shrimp farming.