Quorum-quenching for bacterial pathogen control and health management in aquaculture: mechanisms, applications,...

The aquaculture sector has grown rapidly in recent years, and it now has a significant impact on global food and nutritional security. Infectious disease outbreaks in aquaculture cause significant losses and also threaten the sustainability. Despite the antimicrobial resistance (AMR), environmental contamination and consumer safety concerns, conventional disease control strategies still rely heavily on chemical antimicrobials. Thus, alternative, eco-friendly disease management approaches are urgently needed. This review describes quorum-quenching (QQ) as an innovative health management approach in aquaculture. Quorum-sensing (QS) is a communication system used by bacteria that depends on cell density. QS regulates gene expression, virulence factor production, and biofilm formation in key aquaculture pathogens, including Vibrio, Aeromonas, Pseudomonas, Edwardsiella, and Flavobacterium species. QQ disrupts QS signal networks through enzymatic degradation, competitive receptor inhibition, or suppression. In addition to discussing QS signal molecules and regulatory pathways, this review summarizes and critically evaluates enzymatic and non-enzymatic QQ mechanisms, including lactonases, acylases, oxidoreductases, and small-molecule inhibitors. Practical applications of QQ in aquaculture, including QQ probiotics (QQPs), functional feeds, water treatment systems, biofilm control and host immune modulation, have also been highlighted. While QQ offers a promising alternative to traditional antimicrobials. Translating this technology to field scale applications presents critical challenges. Specifically, the broad-spectrum nature of some QQ agents raises concerns regarding target specificity and the unintended disruption of beneficial native microbiomes. Furthermore, the long term environmental ecological impacts of introducing foreign QQ enzymes or organisms into complex aquatic ecosystems requires rigorous evaluation. Crucially, QQ exerts less selective pressure than bactericidal agents, the potential for pathogens to develop resistance mechanisms such as receptor modification or signal bypassing must be carefully monitored. This study focuses on research pertinent to quorum-quenching in aquaculture systems and is based on a narrative synthesis of peer-reviewed literature that was obtained from major scientific databases. Mechanistic findings, aquaculture application, and translational possibilities in field settings are highlighted.