Multiplex droplet digital PCR assay for detection of Flavobacterium psychrophilum and Yersinia ruckeri in Norwegian aquaculture

• Published in: Journal of Microbiological Methods
• Main Authors: Lewin, Anna, Haugen, Tone, Netzer, Roman, Tøndervik, Anne, Dahle, Stine Veronica Wiborg, Hageskal, Gunhild
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2020
• Subjects: ddPCR; Y. ruckeri; psychrophilum; AquacultureRASF; F. psychrophilum; RAS; Aquaculture; Atlantic salmon; Salmo salar
• Online Access: https://hdl.handle.net/11250/3024882; https://doi.org/10.1016/j.mimet.2020.106044

We report the development of ddPCR assays for single and simultaneous detection of the bacterial pathogens Flavobacterium psychrophilum and Yersinia ruckeri in water from land-based recirculation aquaculture systems (RAS), producing Atlantic salmon (Salmo salar) smolt. The method was tested and verified for use in water analyses from RAS production sites, and proved to be specific and with sensitivity 0.0011 ng DNA for F. psychrophilum and 1.24 ng for Y. ruckeri. These bacteria are important fish pathogens that have caused reoccurring salmonid infection disease in RAS. Monitoring pathogen levels in water samples could be a useful alternative surveillance strategy to evaluate operational risk assessment connected to stress factors. Water quality is essential for fish health and growth in RAS production in general, and high or increasing levels of these pathogens in the RAS water may generate an early indication of unfavourable conditions in the RAS environment, and give directions to operational actions. This approach may reduce fish mortality, reduce production loss, and offer more effective and targeted preventive measures within RAS production. publishedVersion