Dong Jing, Li Shengping, Zhou Shun, Liu Yongtao, Yang Qiuhong, Xu Ning, Yang Yibin, Cheng Bo, Ai Xiaohui
Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China.
College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
Int J Mol Sci. 2025 Mar 6;26(5):2370. doi: 10.3390/ijms26052370.
() is an opportunistic and foodborne pathogen widely spread in the environments, particularly aquatic environments. Diseases caused by in freshwater aquaculture result in huge economic losses every year. The increasing emergence of antibiotic resistance has limited the application of antibiotics in aquaculture. Aerolysin (AerA), the main virulence factor produced by has been identified as a promising target for developing drugs controlling infection. Here, we found that the natural compound amentoflavone (AMF) with the MIC of 512 μg/mL against could dose-dependently reduce the hemolysis of AerA, ranging from 0.5 to 4 μg/mL. Molecular docking and dynamics simulation results predicted that AMF could directly bind to domain 3 of AerA via Pro333 and Trp375 residues. Then, the binding sites were confirmed by fluorescence quenching assays. The results of heptamer formation demonstrated that the binding of AMF could affect the formation of oligomers and result in the loss of pore-forming activity. Cell viability assay showed that AerA after treatment with AMF ranging from 0.5 to 4 μg/mL could significantly reduce AerA-mediated cytotoxicity. Moreover, experimental therapeutics results showed that channel catfish infected with and then administered with 20 mg/kg AMF at intervals of 12 h for 3 days could increase the survival rate by 35% compared with the positive control after a 10-day observation. These findings provided a novel approach to developing anti-infective drugs and a promising candidate for controlling infection in aquaculture.
（某病原体名称）是一种机会性食源性病原体，广泛存在于环境中，尤其是水生环境。该病原体在淡水养殖中引发的疾病每年都会造成巨大经济损失。抗生素耐药性的不断出现限制了抗生素在水产养殖中的应用。气溶素（AerA）是该病原体产生的主要毒力因子，已被确定为开发控制该病原体感染药物的一个有前景的靶点。在此，我们发现对该病原体最低抑菌浓度为512μg/mL的天然化合物穗花杉双黄酮（AMF），在0.5至4μg/mL范围内可呈剂量依赖性降低AerA的溶血活性。分子对接和动力学模拟结果预测，AMF可通过Pro333和Trp375残基直接与AerA的结构域3结合。随后，通过荧光猝灭试验证实了结合位点。七聚体形成结果表明，AMF的结合会影响寡聚体的形成并导致成孔活性丧失。细胞活力测定表明，用0.5至4μg/mL的AMF处理后的AerA可显著降低AerA介导的细胞毒性。此外，实验治疗结果显示，感染该病原体的斑点叉尾鮰，以12小时的间隔给予20mg/kg AMF，持续3天，在10天观察期后，与阳性对照组相比，存活率可提高35%。这些发现为开发抗感染药物提供了一种新方法，并为控制水产养殖中的该病原体感染提供了一个有前景的候选药物。
