The Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, 361021, China.
The Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Jimei University, Xiamen, 361021, China; Xiamen Key Laboratory for Feed Quality Testing and Safety Evaluation, Fisheries College, Jimei University, Xiamen, 361021, China.
Fish Shellfish Immunol. 2023 Mar;134:108575. doi: 10.1016/j.fsi.2023.108575. Epub 2023 Feb 2.
Yellow drum (Nibea albiflora), a commercially important fish species in the coastal regions of southeast China, is highly susceptible to red-head disease caused by Vibrio harveyi B0003. Probiotics have been shown to enhance disease resistance in fish, but whether commensal probiotics could improve of the resistance to red-head disease in yellow drum and possible mechanisms has yet not been reported. A six-week feeding trial was conducted to investigate the red-head disease resistance potentials of five probiotic candidates (Bacillus megaterium B1M2, B. subtilis B0E9, Enterococcus faecalis AT5, B. velezensis DM5 and B. siamensis B0E14), and the liver health, serum and skin immunities, gut and skin mucosal microbiota of yellow drum were determined to illustrate the possible mechanisms. The results showed that autochthonous B. subtilis B0E9 and E. faecalis AT5 (particularly E. faecalis AT5, P < 0.05) effectively improved red-head disease resistance in yellow drum. Furthermore, B. subtilis B0E9 and E. faecalis AT5 (particularly E. faecalis AT5) efficiently improve liver health by improving liver morphology and decreasing serum glutamic oxaloacetic transaminase and glutamic propylic transaminase activities pre and post challenged with V. harveyi B0003 (P < 0.05). B. subtilis B0E9 and E. faecalis AT5 led to significant improvement (P < 0.05) in the serum complement 3 content (un-detected after challenged with V. harveyi B0003), lysozyme activity and skin mucosal immunity (such as IL-6, IL-10 and lysozyme expression) pre and post challenged with V. harveyi B0003, which was generally consistent with the cumulative mortality after challenged with V. harveyi B0003. This induced activations of serum and skin mucosal immunities were consistent with the microbiota data showing that B. subtilis B0E9 and E. faecalis AT5 modulated the overall structure of intestinal and skin mucosal microbiota, and in particular, the relative abundance of potentially pathogenic Achromobacter decreased while beneficial Streptococcus, Rothia, and Lactobacillus increased in fish fed with B. subtilis B0E9 and E. faecalis AT5. Overall, autochthonous B. subtilis B0E9 and E. faecalis AT5 (particularly E. faecalis AT5) can improve liver health, serum and skin immunities (especially up-regulated lysozyme activity and inflammation-related genes expression), positively shape gut and skin mucosal microbiota, and enhance red-head disease resistance of yellow drum.
黄姑鱼（Nibea albiflora）是中国东南沿海地区一种具有商业价值的鱼类，易患哈维弧菌 B0003 引起的红头病。益生菌已被证明能增强鱼类的抗病能力，但共生益生菌是否能提高黄姑鱼对红头病的抵抗力及其可能的机制尚未有报道。本研究进行了为期 6 周的投喂试验，以研究 5 种益生菌候选物（巨大芽孢杆菌 B1M2、枯草芽孢杆菌 B0E9、粪肠球菌 AT5、解淀粉芽孢杆菌 DM5 和暹罗芽孢杆菌 B0E14）对黄姑鱼红头病抵抗力的影响，并测定了黄姑鱼的肝脏健康状况、血清和皮肤免疫、肠道和皮肤黏膜微生物群，以阐明可能的机制。结果表明，本土的枯草芽孢杆菌 B0E9 和粪肠球菌 AT5（特别是粪肠球菌 AT5，P<0.05）能有效提高黄姑鱼的红头病抵抗力。此外，枯草芽孢杆菌 B0E9 和粪肠球菌 AT5（特别是粪肠球菌 AT5）通过改善肝脏形态和降低哈维弧菌 B0003 攻毒前后血清谷氨酸草酰乙酸转氨酶和谷氨酸丙氨酸转氨酶活性，有效改善了肝脏健康（P<0.05）。枯草芽孢杆菌 B0E9 和粪肠球菌 AT5 显著提高了血清补体 3 含量（哈维弧菌 B0003 攻毒后无法检测到）、溶菌酶活性和皮肤黏膜免疫（如 IL-6、IL-10 和溶菌酶表达）（P<0.05），这与哈维弧菌 B0003 攻毒后的累计死亡率基本一致。这些诱导的血清和皮肤黏膜免疫激活与微生物群数据一致，表明枯草芽孢杆菌 B0E9 和粪肠球菌 AT5 调节了肠道和皮肤黏膜微生物群的整体结构，特别是潜在致病性的不动杆菌属的相对丰度降低，而有益的链球菌属、罗氏菌属和乳杆菌属在投喂枯草芽孢杆菌 B0E9 和粪肠球菌 AT5 的鱼中增加。总的来说，本土的枯草芽孢杆菌 B0E9 和粪肠球菌 AT5（特别是粪肠球菌 AT5）可以改善肝脏健康、血清和皮肤免疫（特别是上调溶菌酶活性和炎症相关基因表达）、积极塑造肠道和皮肤黏膜微生物群，并增强黄姑鱼的红头病抵抗力。
