Phage therapy — the use of naturally occurring viruses known as bacteriophages to eliminate pathogenic bacteria — is moving steadily from the laboratory to the field. Long seen as a scientific curiosity, it now appears poised to play a decisive role in improving biosecurity and sustainability across the aquaculture sector. By providing a natural alternative to antibiotics, it addresses two of the industry’s most pressing challenges: the growing threat of antimicrobial resistance and the massive economic losses associated with bacterial disease outbreaks.
Early signs of this transition are already visible. In Asia, particularly in Vietnam and Thailand, commercial trials have demonstrated promising results in shrimp hatcheries affected by Vibrio infections. Similarly, in Europe, research teams in Norway and France are testing phage-based treatments against Tenacibaculum and Flavobacterium species, which cause ulcerative diseases in salmon and trout. In North America, start-ups such as Intralytix and Fixed Phage have reported progress in developing aquaculture-grade phage formulations with stable shelf lives, a key step toward industrial scalability.
Beyond aquaculture, phage therapy has already achieved regulatory milestones that strengthen its credibility. In 2019, the U.S. Food and Drug Administration approved a phage-based additive to control Listeria monocytogenes in ready-to-eat foods, setting a precedent for future veterinary and aquaculture applications. The European Medicines Agency and several national regulators, including those in Denmark and the Netherlands, are also exploring frameworks to accommodate “living biologicals” such as phages within veterinary medicine.
Their appeal lies in a combination of factors. Phages replicate naturally within bacterial hosts, target pathogens with high specificity, and leave no chemical residues, offering an ecologically sound solution that aligns with the aquaculture industry’s growing commitment to environmental responsibility.
Still, the journey toward widespread use remains complex. Validation requires large-scale in vivo studies to confirm that phage cocktails consistently perform under real farming conditions and effectively reduce mortality rates. Regulatory uncertainty continues to slow progress, as no harmonized international framework yet exists to classify and approve these biological agents. Meanwhile, commercialization depends on the development of stable, easy-to-use formulations — such as dry powders or encapsulated pellets — that can be applied at scale and withstand varying farm conditions worldwide.
Despite these obstacles, momentum is clearly building. As public concern over antibiotic resistance intensifies and research yields more field-ready solutions, phage therapy is emerging as a credible, science-driven alternative. Its progress may well mark the beginning of a new biosecurity paradigm for aquaculture — one that unites biotechnology, sustainability, and precision disease control under the same banner.
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Phage therapy – a natural alternative to antibiotics – is gaining ground in aquaculture