Nanotechnology has become an important tool for fish disease prevention and treatment. The current study was carried out to evaluate the efficacy of dietary thyme essential oil (TEO) and its nano-emulsion (TEO-NE) for motile Aeromonas septicemia prevention (MAS) in Oreochromis niloticus after in vitro evaluation. Aeromonas hydrophila was isolated from naturally diseased Oreochromis niloticus and Clarias gariepinus showed signs of septicemia and congestion of internal organs. Prevalence of MAS among diseased O. niloticus and C. gariepinus was 86.9 and 44.4%, respectively. The obtained isolates were identified as Aeromonas hydrophila by molecular assay and found to be highly pathogenic as they contained hemolysin and cytotoxic enterotoxin virulence genes. Experimental infection and medial lethal concentration were performed and it was 1.5 × 10⁴. TEO-NE was synthesized by ultrasonication and characterized by TEM, ATR-FTIR, and zeta potential. The antibacterial activity of TEO-NE was noticed at the least concentration during in vitro evaluation. TEO-NE succeeded in preventing MAS in dietary fed O. niloticus with no mortality compared to 10 and 80% O. niloticus groups fed TEO and positive control group, respectively. Dietary TEO-NE induced significant increase in IgM, IL-1β, and lysozyme. Liver and kidney functions were within the normal levels in groups fed TEO and TEO-NE.

纳米技术已成为鱼病防治的重要工具。目前的研究旨在评估膳食百里香精油 (TEO) 及其纳米乳剂 (TEO-NE)在体外评估后对尼罗罗非鱼中活动性气单胞菌败血症预防 (MAS)的功效。从自然患病的尼罗罗非鱼中分离出嗜水气单胞菌，而Clarias gariepinus显示出败血症和内脏充血的迹象。患病的O. niloticus和C. gariepinus中 MAS 的患病率分别为 86.9% 和 44.4%。所得分离株经鉴定为嗜水气单胞菌通过分子检测，发现它们具有高致病性，因为它们含有溶血素和细胞毒性肠毒素毒力基因。进行了实验感染和中间致死浓度，为1.5 × 10 ⁴。TEO-NE 通过超声合成，并通过 TEM、ATR-FTIR 和 zeta 电位表征。在体外评价中，TEO-NE 在最低浓度下的抗菌活性被注意到。与分别饲喂 TEO 的10% 和 80% 的尼罗罗非鱼组和阳性对照组相比，TEO-NE 成功地预防了日粮喂养的尼罗罗非鱼中的MAS，并且没有死亡率。膳食 TEO-NE 诱导 IgM、IL-1β 和溶菌酶显着增加。喂食TEO和TEO-NE组的肝肾功能均在正常水平内。