Abhiram A, Krishnan Rahul, Ahalya A K, Shaji Shelina, Pillai Devika, Roshan Rameez, Safeena M P
Department of Aquatic Animal Health Management, Kerala University of Fisheries and Ocean Studies, Kochi, Kerala 682506, India.
Department of Aquatic Animal Health Management, Kerala University of Fisheries and Ocean Studies, Kochi, Kerala 682506, India; State Referral Laboratory for Aquatic Animal Disease Diagnosis and Quality Testing, Kerala University of Fisheries and Ocean Studies, Kochi, Kerala 682506, India.
Vaccine. 2025 Aug 30;62:127508. doi: 10.1016/j.vaccine.2025.127508. Epub 2025 Jul 17.
The development of an effective vaccine for Oreochromis niloticus (Tilapia) against Aeromonas hydrophila, a major pathogen in aquaculture, is crucial for enhancing disease resistance and sustainability in fish farming. This study investigates the use of calcium phosphate (CaP) nanoparticles conjugated with the outer membrane protein (OMP) of A. hydrophila as a novel vaccine delivery system, referred to as CaP-OMP. Specific IgM response and Opsonophagocytic killing activity (OPKA) demonstrated improved Aeromonas clearance in vaccinated fish. Furthermore, immune gene expression analysis was performed using quantitative PCR (qPCR) to monitor the expression levels of key immune genes. The results showed a significant upregulation of these immune markers in the CaP-OMP vaccinated groups compared to that of OMP vaccinated groups, suggesting enhanced activation of both the innate and adaptive immune responses. The protective efficacy of the vaccine was demonstrated by a relative percentage survival (RPS) of 85.7 %, indicating significantly lower mortality in the CaP-OMP vaccinated group compared to controls following a challenge study with virulent A. hydrophila. Overall, This oral vaccine approach offers a non-invasive alternative for fish immunization and underscores the potential of calcium phosphate nanoparticles conjugated with outer membrane proteins as a promising vaccine platform for aquaculture. The enhanced immune response, combined with targeted antigen delivery, positions this strategy as a viable tool for controlling A. hydrophila infections in Tilapia, contributing to improved disease management in aquaculture.
开发一种针对尼罗罗非鱼（罗非鱼）的有效疫苗，以对抗水产养殖中的主要病原体嗜水气单胞菌，对于增强养鱼业的抗病能力和可持续性至关重要。本研究调查了与嗜水气单胞菌外膜蛋白（OMP）偶联的磷酸钙（CaP）纳米颗粒作为一种新型疫苗递送系统（称为CaP-OMP）的用途。特异性IgM反应和调理吞噬杀伤活性（OPKA）表明接种疫苗的鱼体内嗜水气单胞菌清除能力有所提高。此外，使用定量PCR（qPCR）进行免疫基因表达分析，以监测关键免疫基因的表达水平。结果显示，与接种OMP疫苗的组相比，CaP-OMP接种组中这些免疫标志物显著上调，表明先天免疫和适应性免疫反应均得到增强。疫苗的保护效力通过85.7%的相对存活率（RPS）得以证明，这表明在用强毒嗜水气单胞菌进行攻毒试验后，CaP-OMP接种组的死亡率明显低于对照组。总体而言，这种口服疫苗方法为鱼类免疫提供了一种非侵入性替代方案，并强调了与外膜蛋白偶联的磷酸钙纳米颗粒作为水产养殖中有前景的疫苗平台的潜力。增强的免疫反应与靶向抗原递送相结合，使该策略成为控制罗非鱼嗜水气单胞菌感染的可行工具，有助于改善水产养殖中的疾病管理。
