Oniris, INRAE, BIOEPAR, Nantes, France.
Oniris, INRAE, BIOEPAR, Nantes, France.
Fish Shellfish Immunol. 2023 Apr;135:108664. doi: 10.1016/j.fsi.2023.108664. Epub 2023 Mar 7.
Furunculosis caused by Aeromonas salmonicida subsp salmonicida (Ass) is a medically and economically important bacterial disease in salmonid farms that requires therapeutic measures to prevent and control the disease. Evaluation of the effectiveness of traditional measures such as antibiotics or vaccines usually requires infecting fish experimentally. The objective of this study is to develop a method of infectious challenge of large (250-g) Rainbow trout by immersion close to natural infection conditions. We compare mortality, morbidity and anti-Ass antibody production of Rainbow trout following different bathing times (2, 4, 8 and 24 h) at a final bacterial concentration of 10 CFU/mL. One hundred sixty fish divided in five groups corresponding to the 4 bathing times and the non-challenged group were studied. The 24 h contact duration resulted in the infection of all fish, with a mortality rate of 53.25%. The challenged fish developed acute infection with symptoms and lesions (inappetance, altering of swimming behaviour, presence of boils) similar to those observed in furunculosis, and produced antibodies against the bacterium at 4 weeks after challenging, in contrast with the non-challenged group.
类疖病由杀鲑气单胞菌亚种（Ass）引起，是鲑鱼养殖场中一种具有重要医学和经济意义的细菌性疾病，需要采取治疗措施来预防和控制该病。评估抗生素或疫苗等传统措施的有效性通常需要通过实验感染鱼类。本研究的目的是开发一种通过浸泡在接近自然感染条件下对大（250 克）虹鳟鱼进行传染性挑战的方法。我们比较了在终浓度为 10 CFU/mL 的条件下，不同沐浴时间（2、4、8 和 24 小时）对虹鳟鱼死亡率、发病率和抗 Ass 抗体产生的影响。将 160 条鱼分为五组，分别对应于 4 种沐浴时间和未挑战组。24 小时的接触时间导致所有鱼都受到感染，死亡率为 53.25%。受挑战的鱼出现了急性感染症状和病变（食欲不振、游泳行为改变、疖疮），与疖病观察到的症状和病变相似，并且在挑战后 4 周产生了针对该细菌的抗体，而未受挑战的鱼则没有。
