Prophage-Derived Molecules as Anti-Vibrio Agents in Aquaculture: Mechanisms of Biofilm Control and Virulence Suppression.

Vibriosis causes substantial losses in marine and brackish-water aquaculture, while increasing antimicrobial resistance limits the effectiveness of conventional antibiotic treatment. Biofilm formation and quorum-sensing-controlled virulence further contribute to the persistence of pathogenic Vibrio species. Prophages integrated into Vibrio genomes encode proteins and regulatory elements that may provide alternative approaches for controlling these pathogens. This review evaluates endolysins, polysaccharide depolymerases, nucleases, holins, spanins, tailocins, regulatory proteins, and small RNAs associated with prophages and related phages. The available evidence was classified according to molecular origin to distinguish validated prophage-derived molecules from those obtained from temperate or lytic phages and from molecules characterized in non-Vibrio bacteria. Endolysins and depolymerases can disrupt bacterial cells and biofilm matrices, whereas prophage regulatory elements may influence quorum sensing, adhesion, motility, toxin production, and secretion systems. However, the evidence directly supporting prophage-derived anti-Vibrio agents remains limited. Most experimentally demonstrated activity has been reported for endolysins and one validated depolymerase, and many of these molecules originated from lytic rather than temperate phages. No direct Vibrio-specific evidence is currently available for phage-derived nucleases, holins, spanins, or tailocins as isolated control agents. Prophage genomes nevertheless provide an extensive source of regulatory and antimicrobial candidates for further investigation. Progress toward aquaculture application will require experimental validation, effective delivery methods, safety assessment, scalable production, and clear regulatory standards.