Project description:Grass carp is the most produced freshwater fish species in China. However, frequent outbreaks of bacterial diseases caused by Aeromonas ssp. have led to huge economic losses in grass carp farming. Various omics technologies have been used to study the response of grass carp to these pathogens. For instance, the transcriptional profile of the spleen from grass carp challenged with A. hydrophila, which revealed significant enrichment of gene clusters, including phagocytosis, complement system, cytokines, antigen processing and presentation, pattern recognition receptors, cell adhesion molecules, apoptosis, and antioxidant enzymes. Furthermore, a large number of differentially expressed genes related to inflammation were identified in the intestinal transcriptome of grass carp infected with A. hydrophila. However, the immune response of grass carp infected with A. veronii remains unresolved at the multi-omics level. In the present study, an intestinal infection model was established in grass carp using the isolated A. veronii strain EL07, and the differentially expressed genes and proteins in the intestinal and differentially expressed metabolites in serum were analyzed. The results may contribute to a better understanding of the pathogenesis of grass carp enteritis caused A. veronii.