Disease pressure in aquaculture production continues to be a growing issue for the industry. Bacterial pathogens, such as species of Vibrio, Aeromonas hydrophila, and Edwardsiella ictaluri are known pathogens that infect shrimp and catfish, respectively for example. Pathogenicity is considered to be connected to their ability to concentrate in key organs, and once reaching critical levels, become virulent. Antibiotics have been used historically to try and control these effects. While it is debatable whether antibiotic use applied to pond systems is an effective treatment, there is growing recognition that their benefits are outweighed by concerns to eliminate their use.
Aquaculture production cannot be conducted in a sterile environment. Pathogens along with beneficial and innocuous micro-organisms are always present in the microbiome, though not always virulent. Developing production strategies that mitigate the opportunistic growth of pathogenic bacteria through more holistic microbial management may present farmers with additional and, more sustainable, tools to suppress disease pressure and preserving production.
Probiotics are being broadly evaluated as an alternative management practice to antibiotic use. Research is now showing that the use of select probiotics in aquaculture production can suppress Vibrio growth in pond water, reduce their accumulation in the gut tract and exoskeleton of shrimp, and prevent problematic species from reaching critical virulent concentrations. Laboratory testing using proprietary blends of lactic acid bacteria and bacilli show that select strains of these species can broadly suppress Vibrio growth, as well as Aeromonas hydrophila, and Edwardsiella ictaluri. Growth experiments also show a lack of accumulation of Vibrio in shrimp during hatchery and nursery growth, as well as preliminary data for other pathogens in catfish. Field studies are now in progress to validate and extend these results from well controlled research studies to practical, cost effective tools for commercial farmers and production managers to use in improving aquaculture production.