Quorum‐sensing interference in vibrios

Abstract Vibrios belonging to the Harveyi clade and the Splendidus clade are important pathogens that cause high economic losses in aquaculture. To control bacterial diseases, antibiotics have been widely applied in aquaculture worldwide for many years, contributing to the development and spread of antibiotic resistance. To further limit the use of antibiotics without affecting the envisaged sustainable growth of the sector, novel therapies to control diseases are urgently needed. As the virulence of many bacterial pathogens is controlled by quorum sensing, quorum‐sensing interference has been the most intensively studied antivirulence therapy. It aims to disarm rather than kill the pathogens to prevent them from attacking their host. This strategy is believed to impose less selective pressure upon pathogens for resistance development when compared to antibiotics. In this review, we provide an overview of quorum‐sensing systems in vibrios belonging to the Harveyi clade and the Splendidus clade, as well as the virulence‐related phenotypes controlled by these systems. The major quorum‐sensing systems in these bacteria include three‐channel quorum‐sensing systems and indole signalling. Furthermore, we discuss different agents that interfere with quorum‐sensing systems and that protect aquatic animals from disease caused by Harveyi clade and Splendidus clade vibrios. These agents include small molecules (both natural and synthetic) that interfere with three‐channel quorum‐sensing systems or with indole signalling and signal molecule‐degrading bacteria. Finally, we identify knowledge gaps and propose some frontiers for further research in order to move this promising field forward.