Department of Fish Health and Management, Central Laboratory for Aquaculture Research, Agriculture Research Center, Abbassa, Abo Hammad, Sharqia, Egypt.
Department of Poultry and Fish Diseases, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt.
Vet Med Sci. 2024 Nov;10(6):e70052. doi: 10.1002/vms3.70052.
This study aimed to determine the antimicrobial effects of ethanolic extracts of Ulva sp. and garlic (Allium sativum) powder ethanolic extracts against Vibrio harveyi in vitro. The stimulatory effects of Ulva sp. extract (UE) and garlic powder extract (GPE) on the growth performance and innate immune responses of white-leg shrimp, Litopenaeus vannamei, and their challenge against V. harveyi infection were also investigated. A commercial shrimp diet (36.1% protein) was enriched with 0.5, 1.0 and 2.0 g UE/kg diet and 2, 4 and 6 g GPE/kg diet, whereas the control group was free of any supplement. Health juveniles of L. vannamei (average weight 2-3 g) were distributed in 21 fiberglass reinforced plastic (FRP) tanks (500-L capacity) at a stocking density of 300 animals/tank to represent each treatment in triplicate. The animals were fed ad libitum on the experimental diets up to satiety four times daily for 60 days. The phytochemical analysis of ethanolic extracts of Ulva sp. and garlic powder evoked their richness of several bioactive compounds showing significant antibacterial activity against V. harveyi. The GPE exhibited a higher inhibition zone than that of the UE. The supplemented diets did not significantly affect weight gain %, final weight, feed conversion ratio, specific growth rate and survival rates of white shrimp compared to those fed on the control diet. Significant increases were observed in total haemocyte count, phagocytosis and phagocytic index of all treatments compared with the control group. There were significant increases in serum total protein, acid phosphatase activity, alkaline phosphatase, lysosomal enzyme activity, phenoloxidase activity and superoxide dismutase activity with offered diets with increasing the levels of ethanolic extracts of Ulva sp. and garlic powder up to 2.0 g UE/kg diet and 6 g GPE/kg diet, respectively. The ethanolic extraction of Ulva sp. and garlic powder-supplemented diet groups, particularly at treatments of 2.0 and 6 g GPE/kg diet, respectively, significantly reduced the shrimp mortality induced by V. harveyi infection when compared with the control group. The net results evoked that ethanolic extraction of Ulva sp. (2.0 g UE/kg) and garlic powder (6 g GPE/kg diet) enhanced the immune response and disease resistance of the white-leg shrimp, L. vannamei. It is also noted that the GPE is more efficient than the UE in vitro and in vivo investigations.
本研究旨在确定 Ulva sp. 的乙醇提取物和大蒜（Allium sativum）粉乙醇提取物对体外哈维弧菌的抗菌作用。还研究了 Ulva sp. 提取物 (UE) 和大蒜粉提取物 (GPE) 对凡纳滨对虾（Litopenaeus vannamei）生长性能和先天免疫反应的刺激作用，以及它们对哈维弧菌感染的挑战。商业虾饲料（36.1%蛋白质）中添加了 0.5、1.0 和 2.0 g UE/kg 饲料和 2、4 和 6 g GPE/kg 饲料，而对照组则没有任何补充。健康的凡纳滨对虾幼体（平均体重 2-3 g）以 300 尾/箱的密度分布在 21 个玻璃纤维增强塑料（FRP）水箱（500-L 容量）中，每组重复 3 次。动物每天自由摄食实验饲料 4 次，直至饱食，持续 60 天。对 Ulva sp. 的乙醇提取物和大蒜粉的植物化学分析表明，它们富含几种生物活性化合物，对哈维弧菌表现出显著的抗菌活性。GPE 表现出的抑菌圈大于 UE。与对照组相比，补充饲料对虾的增重百分比、最终体重、饲料转化率、特定生长率和存活率没有显著影响。与对照组相比，所有处理组的总血细胞计数、吞噬作用和吞噬指数均显著增加。随着 Ulva sp. 和大蒜粉乙醇提取物水平的增加，血清总蛋白、酸性磷酸酶活性、碱性磷酸酶、溶酶体酶活性、酚氧化酶活性和超氧化物歧化酶活性均显著增加，最高分别为 2.0 g UE/kg 饲料和 6 g GPE/kg 饲料。与对照组相比，添加 Ulva sp. 乙醇提取物（2.0 g UE/kg）和大蒜粉（6 g GPE/kg 饲料）的饲料组，特别是在 2.0 和 6 g GPE/kg 饲料处理组，显著降低了哈维弧菌感染引起的虾死亡率。实验结果表明，Ulva sp. 的乙醇提取物（2.0 g UE/kg）和大蒜粉（6 g GPE/kg 饲料）增强了凡纳滨对虾的免疫反应和抗病能力。还注意到，在体外和体内研究中，GPE 比 UE 更有效。
