“Implementation of antimicrobial resistance surveillance in farmed aquatic animals: The UK example. (6295)”

Implementation of antimicrobial resistance surveillance in farmed aquatic animals: The UK example.

Introduction: Antimicrobial resistance (AMR) is a globally significant public health issue, driven by the use of antimicrobial agents in human and animal health, and food production. The contribution of fish farming to the spread of AMR is poorly documented, highlighting an urgent need to generate evidence at national level. The World Organisation for Animal Health recommends that countries implement AMR surveillance and monitoring programmes in aquaculture. While both passive and active AMR surveillance systems exist in the United Kingdom (UK) for terrestrial livestock, similar systems are lacking for the aquaculture sector. This project aimed to address this gap by piloting two surveillance projects one for farmed trout intended for food consumption, and another for imported ornamental fish. The presentation will also outline efforts to develop an active surveillance system for farmed trout at slaughter.

Material and Methods: The pilot projects identified indicator bacterial species, assessed agar plates, tested non-lethal sampling and considered logistical requirements for implementation. Samples were analysed for phenotypic resistance using minimum inhibitory concentration and disc diffusion methods, following CLSI VET03 and VET04 guidelines. Selected isolates were sequenced for the presence of antimicrobial resistances genes (ARGs) and genetic mobile elements, allowing comparison between phenotypic and genotypic results. Additionally, an antibiotic residue assay was developed using liquid chromatography tandem mass spectrometry to determine the presence of antibiotics in the transport water of imported ornamental fish.

Results: Three bacterial species were identified as suitable indicators for the passive AMR surveillance in farmed trout, and five for the active AMR surveillance in ornamental fish. Non – lethal sampling was founded to be not suitable, as different indicator bacteria were present in tissue and water samples. In most cases, the phenotypic and genotypic results were in alignment. Antibiotic residues were detected in ornamental fish transport water.

Conclusion: The intensification of aquatic animal farming, like other animal production systems, facilitates the spread of pathogens and may increase the use of reliance on veterinary medicines for disease management. While data analysis for farmed trout is ongoing, pilot findings indicate that antimicrobials continue to be routinely added to the transport water of ornamental fish. The bacteria in the water or fish can act as reservoir of ARGs and contribute to the spread of AMR. This poses a potential risk to human health, particularly for industry workers and fish hobbyists. These findings highlight the urgent need for competent authorities to establish AMR surveillance systems for aquatic animals.

1. PAPADOPOULOU, ATHINA, CEFAS, Presenter
2. COYLE, NICOLA, CEFAS, Author
3. SMITH, ISOBEL, UNIVERSITY OF SURREY, Author
4. LANGFORD, NIAMH, UNIVERSITY OF SURREY, Author
5. MASKREY, BEN, CEFAS, Author
6. LIGHT, EDEL, VMD, Author
7. VERNER-JEFFREYS, DAVID, WORLDFISH, Author