Bacteriophages could reduce antibiotic use

A new international research project will use bacteria’s natural enemies, bacteriophages, to control bacterial diseases in aquaculture. The Innovation Fund Denmark has invested EUR 1.8 million in the project.

Aquaculture is the fastest growing industry in animal food production in the world and supports an increasing global demand for healthy food. Fish farming has a signi cantly lower climate footprint than other animal production, but disease in the larval and brood stages of sh constitutes a signi cant bottleneck in sh production and causes large economic losses in the industry. Fish fry cannot be vaccinated, and antibiotics are therefore often used in the treatment of diseases. is entails a risk of the development and transfer of antibiotic resistance, which partly reduces the e ectiveness of the treatment and partly increases the risk of the spread of antibiotic resistance to food and the environment.

Bacteriophages may be a key player in the aquaculture sector’s green transition

In a project coordinated by Professor Mathias Middelboe, Department of Biology, University of Copenhagen, researchers from the University of Copenhagen and the Technical University of Denmark collaborates with the key biotech and aquaculture business Danish Technological Institute, DanAqua, KSK Aqua, Aller Aqua, Carus Animal Health and Fixed Phage to develop a new environmentally friendly technology for the treatment of bacterial diseases in trout farming. e starting point for the project is to use the bacteria’s natural enemies, the bacteriophages, in the ght against pathogenic bacteria in aquaculture. e goal is that the project’s results can contribute to phasing out the use of antibiotics in the aquaculture industry and contribute to a sustainable development and restructuring of the sector, by preparing new products to the market. e previous research into bacteriophage-based control of sh diseases by Professor Mathias Middelboe, his team and collaborators, has shown promising results in recent years, and now the Innovation Fund Denmark together with the English company Carus Animal Health and seven other Danish and British companies have invested 2.8 million Euro in taking the next step in the development of antimicrobial products that can reduce disease outbreaks in trout rearing.

Antibiotic use hinders trout production

Rainbow trout is one of the most important sh species produced in the EU (24 producer countries, >250.000 t produced per year with a value of >EUR660 million), accounting for ~30% of the global trout production. e increasing global demand for farmed sh for consumption represents a strong driver for the further expansion of the industry. However, an increase in aquaculture production is constrained by the environmental concerns associated with eutrophication, antibiotic spillover etc. Further, a signi cant increase in disease outbreaks in rainbow trout farming during the past 15-20 years as a result of shifting production towards recirculating systems (RAS) has led to a >300% increase in the use of the broadspectrum antibiotic orfenicol reduced production e ciency.

A key barrier for expanding the aquaculture industry are therefore the environmental issues of antibiotic use, and discharge of waste and nutrient to the environment. erefore, directing the industry through a green transition by solving the challenges related to disease issues is an absolute prerequisite for expanding the potential of aquaculture production in the future. e aim of the project is to develop and test one or more prototype phagebased products with documented antagonistic e ects against Flavobacterium psychrophilum for use in the prevention of Rainbow trout Fry Syndrome (RTFS) in rainbow trout RAS aquaculture systems. RTFS causes serious disease outbreaks in most rainbow trout hatcheries with mortalities of up to 80-90% if left untreated. e products are thought to be used preventively as feed supplements or applied to biological lters in recirculated breeding facilities. As the diseases in question are globally widespread and have major negative consequences for the industry throughout the world, products that reduce sh mortality and support sustainable production have great commercial potential.

More speci cally, the expected outcomes of the project are

1) a database of a well-characterized collection of F. psychrophilum phages

2) an optimized production platform for F. psychrophilum phages for pilot scale production

3) safe and stable prophylactic applications of phages tested at farm and lab scale conditions

4) a development and approval plan for selected product types

5) a cost-bene t analysis including the economic and environmental e ects of the technology

6) a market analysis of the proposed phage-based products

7) a pipeline for the regulatory pathways for EU-wide market authorization

Contact: Professor Mathias Middelboe Marine Biology Section, Department of Biology, University of Copenhagen Strandpromenaden 5 3000 Helsingør Denmark

Mission Ocean: A multi-layered initiative to restore ocean health

Facts: The Innovation Fund’s investment: DKK13.5m

Total budget: DKK20.7m

Duration: 3 years

Official title: AQUAPHAGE: Towards a sustainable aquaculture Novel solutions for disease prevention supporting the green transition in aquaculture production.

Technological Institute, DanAqua, KSK Aqua, Aller Aqua, Carus Animal Health, and Fixed Phage and will run for 3 years.