Huang Aiguo, Wei Yanqin, Huang Jialong, Luo Songlin, Wei Tingyu, Guo Jing, Zhang Fali, Wang Yinghui
Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China.
School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
Microorganisms. 2025 Jul 20;13(7):1699. doi: 10.3390/microorganisms13071699.
(SA) is a severe prevalent pathogen, resulting in high morbidity and mortality in the global tilapia industry. With increasing bacterial resistance to antibiotics, alternative strategies are urgently needed. This study aims to investigate the antibacterial activity and the underlying mechanisms of the natural product xanthohumol (XN) against SA infection in tilapia (). The results showed that XN could significantly reduce the bacterial loads of SA in different tissues (liver, spleen and brain) after treatment with different tested concentrations of XN (12.5, 25.0 and 50.0 mg/kg). Moreover, XN could improve the survival rate of SA-infected tilapia. 16S rRNA gene sequencing demonstrated that the alpha-diversity index (Chao1 and Shannon_e) was significantly increased in the XN-treated group (MX group) compared to the SA-infected group (CG group) ( < 0.05), and the Simpson diversity index significantly decreased. The Bray-Curtis similarity analysis of non-metric multidimensional scaling (NMDS) and principal coordinate analysis (PCA) showed that there were significant differences in microbial composition among groups. At the phylum level, the relative abundance of the phyla Actinobacteria, Proteobacteria and Bacteroidetes decreased in the MX group compared to the CG group, while the relative abundance of the phyla Fusobacteria, Firmicutes and Verrucomicrobia increased. Differences were also observed at the genus level; the relative abundance of decreased in the MX group, but the abundance of and increased. Metabolomics analysis revealed that XN changed the metabolic profile of the liver and significantly enriched aspartate metabolism, glycine and serine metabolism, phosphatidylcholine biosynthesis, arginine and proline metabolism, glutamate metabolism, urea cycle, purine metabolism, methionine metabolism, betaine metabolism, and carnitine synthesis. Correlation analysis indicated an association between the intestinal microbiota and metabolites. In conclusion, XN may be a potential drug for the prevention and treatment of SA infection in tilapia, and its mechanism of action may be related to the regulation of the intestinal microbiota and liver metabolism.
无乳链球菌（SA）是一种严重的流行病原体，在全球罗非鱼养殖业中导致高发病率和死亡率。随着细菌对抗生素的耐药性增加，迫切需要替代策略。本研究旨在探讨天然产物黄腐酚（XN）对罗非鱼SA感染的抗菌活性及其潜在机制。结果表明，用不同测试浓度（12.5、25.0和50.0mg/kg）的XN处理后，XN可显著降低不同组织（肝脏、脾脏和大脑）中SA的细菌载量。此外，XN可提高SA感染罗非鱼的存活率。16S rRNA基因测序表明，与SA感染组（CG组）相比，XN处理组（MX组）的α多样性指数（Chao1和Shannon_e）显著增加（P<0.05），辛普森多样性指数显著降低。非度量多维标度（NMDS）和主坐标分析（PCA）的Bray-Curtis相似性分析表明，各组之间的微生物组成存在显著差异。在门水平上，与CG组相比，MX组中放线菌门、变形菌门和拟杆菌门的相对丰度降低，而梭杆菌门、厚壁菌门和疣微菌门的相对丰度增加。在属水平上也观察到差异；MX组中[具体属名1]的相对丰度降低，但[具体属名2]和[具体属名3]的丰度增加。代谢组学分析表明，XN改变了肝脏的代谢谱，并显著富集了天冬氨酸代谢、甘氨酸和丝氨酸代谢、磷脂酰胆碱生物合成、精氨酸和脯氨酸代谢、谷氨酸代谢、尿素循环、嘌呤代谢、蛋氨酸代谢、甜菜碱代谢和肉碱合成。相关性分析表明肠道微生物群与代谢物之间存在关联。总之，XN可能是预防和治疗罗非鱼SA感染的潜在药物，其作用机制可能与肠道微生物群和肝脏代谢的调节有关。
