Yang Ying-Fei, Yamkasem Jidapa, Surachetpong Win, Lin Yi-Jun, You Shu-Han, Lu Tien-Hsuan, Chen Chi-Yun, Wang Wei-Min, Liao Chung-Min
Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan.
Faculty of Veterinary Medicine, Department of Veterinary Microbiology and Immunology, Kasetsart University, Chatuchak, Bangkok, Thailand.
J Fish Dis. 2022 Aug;45(8):1117-1132. doi: 10.1111/jfd.13635. Epub 2022 May 6.
Probiotics have been used to alleviate disease transmission in aquaculture. However, there are limited studies on probiotic use in modulating tilapia lake virus (TiLV). We assessed commercially available probiotic supplements used in TiLV-infected tilapia and performed mortality and cohabitation assays. We developed a mechanistic approach to predict dose-response interactions of probiotic effects on mortality and immune gene response. We used a susceptible-infected-mortality disease model to assess key epidemiological parameters such as transmission rate and basic reproduction number (R ) based on our viral load dynamic data. We found that the most marked benefits of probiotics are significantly associated with immune system enhancements (30%) and reductions in disease transmission (80%) and R (70%) in tilapia populations, resulting in a higher tolerance of farming densities (400 fold) in aquaculture. These findings provide early insights as to how probiotic use-related factors may influence TiLV transmission and the immune responses in TiLV-infected tilapia. Our study facilitates understanding the mode of action of probiotics in disease containment and predicting better probiotic dosages in diet and supplements to achieve the optimal culturing conditions. Overall, our analysis assures that further study of rationally designed and targeted probiotics, or mechanistic modelling is warranted on the basis of promising early data of this approach.
益生菌已被用于减轻水产养殖中的疾病传播。然而，关于益生菌在调节罗非鱼湖病毒（TiLV）方面的应用研究有限。我们评估了用于感染TiLV的罗非鱼的市售益生菌补充剂，并进行了死亡率和同居试验。我们开发了一种机制方法来预测益生菌对死亡率和免疫基因反应的剂量反应相互作用。基于我们的病毒载量动态数据，我们使用了一种易感-感染-死亡疾病模型来评估关键的流行病学参数，如传播率和基本再生数（R）。我们发现，益生菌最显著的益处与罗非鱼群体的免疫系统增强（约30%）、疾病传播减少（约80%）和R减少（约70%）显著相关，从而使水产养殖中的养殖密度耐受性提高（约400倍）。这些发现为益生菌使用相关因素如何影响TiLV传播以及感染TiLV的罗非鱼的免疫反应提供了早期见解。我们的研究有助于理解益生菌在疾病控制中的作用模式，并预测饮食和补充剂中更好的益生菌剂量以实现最佳养殖条件。总体而言，我们的分析确保了基于这种方法有前景的早期数据，有必要对合理设计和靶向的益生菌或机制建模进行进一步研究。
