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.

我们报告了从陆地循环水产养殖系统（RAS）产生水中的细菌鲑鱼黄单胞菌和rerseria ruckeri细菌病原体的同时检测的ddPCR分析方法的发展，产生大西洋鲑鱼（Salmo salar）熏鲑。该方法经过测试和验证，可用于RAS生产现场的水分析，并被证明具有特异性，对嗜热链球菌的灵敏度为0.0011 ng DNA，对R. ruckeri的灵敏度为1.24 ng 。这些细菌是重要的鱼类病原体，已导致RAS中鲑鱼再次感染。监测水样中的病原体水平可能是一种有用的替代监测策略，以评估与压力因素有关的运营风险评估。总体而言，水质对于鱼类健康和RAS产量的增长至关重要，并且RAS水中这些病原体的含量高或在增加可能会在RAS环境中产生不利条件的早期迹象，并为操作提供指导。这种方法可以降低鱼类死亡率，减少生产损失，并在RAS生产中提供更有效和针对性的预防措施。