Virulence mechanisms of bacterial aquaculture pathogens and antivirulence therapy for aquaculture

Abstract

Although aquaculture continues to be the fastest-growing food-producing industry worldwide, the sector faces important challenges with respect to controlling infectious diseases. Indeed, the frequent use of antibiotics, which are traditionally the most important line of defence against bacterial disease, has raised problems related to the development and spread of resistance. As a result, we currently are in a race to develop novel therapeutics that should allow us to continue controlling bacterial disease in the future. In this respect, scientific progress of the past years has allowed us to start understanding the mechanisms by which bacterial pathogens are causing disease. This knowledge in its turn opens up novel possibilities to combat infections by interfering with these mechanisms, a strategy that has been termed antivirulence therapy. In this review, the current knowledge with respect to pathogenicity mechanisms of bacterial aquaculture pathogens is discussed, including adhesion mechanisms, production of extracellular polysaccharides and biofilm formation, production of lytic enzymes (e.g. haemolysins and proteases), mechanisms of iron acquisition, secretion systems and regulatory mechanisms such as quorum sensing and host-pathogen signalling with catecholamine stress hormones. Furthermore, an overview is given of the first steps towards antivirulence therapy for aquaculture, with a focus on quorum sensing disruption as a proof of concept

Dietary supplementation use of Bacillus cereus as quorum sensing degrader and their effects on growth performance and response of Malaysian giant river prawn Macrobrachium rosenbergii juvenile towards Aeromonas hydrophila

“…In addition, some probiotics may outcompete or disrupt the activity of pathogens using QS mechanism. This subsequently controls the expression of virulence factor productions in various aquatic pathogens such as Aeromonas and Vibrio species (Defoirdt, ). The use of QS inhibitors to interfere with signal molecules in bacterial pathogens was shown to increase the resistance of M. rosenbergii larvae to V. campbellii when added into the rearing water (Pande et al., ).…”

The impact of quorum sensing on the virulence ofVibrio anguillarumtowards gnotobiotic sea bass (Dicentrarchus labrax) larvae

“…As a result of the growing awareness that antibiotics should be used with more care, there is a trend towards more strict regulations on the use of antibiotics in the aquaculture sector and on the presence of antibiotic residues in aquaculture products (FAO, 2002). This strategy has been termed antivirulence therapy (Defoirdt, 2014). This strategy has been termed antivirulence therapy (Defoirdt, 2014).…”

Antivirulence Therapy for Animal Production: Filling an Arsenal with Novel Weapons for Sustainable Disease Control

“…Interestingly, vibrios and Aeromonas spp. also respond to catecholamines, and QseC homologues have been reported in these bacteria as well [33].…”