Characterization of the gut microbiota of yellow catfish (Pelteobagrus fulvidraco) infected with Edwardsiella ictaluri

To reveal the changes in the gut microbiota of yellow catfish after being infected by Edwardsiella ictaluri 16S rRNA gene high-throughput sequencing technology was used to analyze the microbial composition and diversity of the healthy and diseased yellow catfish The gut microbial richness and diversity of the diseased fish were significantly lower than those of healthy fish The composition and predicted function of yellow catfish gut microbiota were drastically altered after infection by E ictaluri Fusobacteriota Proteobacteria and Firmicutes were the predominant bacterial phyla in the gut of the healthy fish while Proteobacteria was the dominant phylum in the gut of the diseased fish At the genus level the gut of healthy fish was dominated by Cetobacterium Plesiomonas and Romboutsia while the gut of diseased fish was overwhelmed by the pathogenic E ictaluriand Cetobacterium Plesiomonas and Romboutsia disappeared This is the most characteristic feature of the intestinal microbiota composition of yellow catfish edwardsiellosis The same sequence of E. ictaluri was detected in the intestine of the healthy and the liver and intestine of the diseased fish The anaerobic and gram-positive bacteria were significantly decreased the digestive system immune system and metabolic functions of the gut microbiota were significantly reduced in the diseased fish gut This may be part of the pathogenesis of fish edwardsiellosis