感染草鱼呼肠孤病毒对肠道菌群多样性的影响

为揭示草鱼呼肠孤病毒(Grass Carp Reovirus, GCRV)对草鱼(Ctenopharyngodon idellus)肠道菌群的影响, 在通过人工浸泡方式感染GCRV后, 采用针对16S rRNA基因的高通量测序技术对草鱼肠道菌群的组成和多样性进行了研究。结果显示, 感染组与对照组差异显著(MRPP, Anosim, Adonis, P<0.01), 且感染组肠道菌群的Alpha多样性指数(Shannon-Wienner、Inverse Simpson、Pielou evenness)显著低于对照组(t-test, P<0.05)。此外, 肠道菌群在感染组个体间差异显著大于对照组(Wilcoxon test,P<0.05), 表明患病草鱼肠道菌群失去原有平衡而变得紊乱。尽管病毒感染组和对照组草鱼肠道优势菌门均为Proteobacteria、Firmicutes、Bacteroidetes、Fusobacteria, 但在OTU水平仍表现出明显的变化, 如OTU_69(Pasteurellaceae)、OTU_504(Comamonadaceae)和OTU_1898(Cetobacterium)在感染GCRV组丰度显著降低(t-test, P<0.05), 也表明GCRV感染可使草鱼肠道微生态发生紊乱。肠道菌群结构稳定对于宿主健康具有重要意义, 研究患病鱼肠道菌群状况为鱼类常见疾病的防控提供科学依据, 也为健康养殖提供参考。

EFFECTS OF REOVIRUS INFECTION ON THE INTESTINAL MICROBIOTA DIVERSITY OF GRASS CARP (CTENOPHARYNGODON IDELLA)

The grass carp (Ctenopharyngodon idellus) infected with the hemorrhage virus was used to analyze the intestinal microbiota by using high-throughput sequencing. The results showed that microbiota significantly differed between grass carp reovirus (GCRV)-infected and control grass carp (multiple response permutation procedure (MRPP), analysis of similarity (Anosim), and Adonis; P<0.01). When we compared alpha diversity, we found that Shannon-Wiener index, inverse of Simpson's original index and Pielou’s evenness index of intestinal microbiota were all significantly decreased after infecting with GCRV (independent samplest-test, P<0.05). Besides, we found that the individual difference within GCRV-infected group was significantly greater than those in the controls (Wilcoxon signed-rank test,P<0.05), suggesting that the intestinal microbiota in GCRV-infected grass carps became disorganized and lost their original balance. Proteobacteria, Firmicutes, Fusobacteriaceae, and Bacteroidetes were dominant phylum in both GCRV-infected group and controls. However, the relative abundance of operational taxonomic units (OTUs) between the two groups was different. For example, OTU_69 (Pasteurellaceae), OTU_504 (Comamonadaceae), and OTU_1898 (Cetobacterium) were all significantly lower than that of controls (t-test, P<0.05), confirming that GCRV could make intestinal microbiota of grass carps disorganized. The stability of intestinal microbiota is important for health of host. By detecting changes in the intestinal microbiota of GCRV-infected grass carp, we will be able to provide theoretical basis and data reference for the prevention and treatment of common disease of farmed fish, as well as providing a reference for healthy breeding.