Correlation Analysis of the Transcriptome and Gut Microbiota in Salmo trutta Resistance to Aeromonas salmonicida

Aeromonas salmonicida is a major pathogenic bacterium that poses a significant threat to salmonid fish. Yadong County, located in the Xizang Autonomous Region, is renowned for its characteristic industry of Salmo trutta aquaculture. In recent years, the outbreak of Bacterial Gill Disease (BGD) has led to substantial economic losses for S. trutta farmers. Our prior research identified A. salmonicida as one of the primary culprits behind BGD. To mitigate the impact of A. salmonicida on S. trutta, we conducted a comprehensive study aimed at identifying genes associated with resistance to A. salmonicida. This involved transcriptome sequencing and 16S rRNA sequencing of intestinal flora, providing valuable insights for the study of disease resistance in S. trutta. In this study, we identified 324 genera with 5171 ASVs in the susceptible group and 293 genera with 5669 ASVs in the resistant group. Notably, Methylobacterium and Sphingomonas were common bacteria present in the salmon's gut, and their proportions remained relatively stable before and after infection. Shewanella, with its antagonistic relationship with Aeromonas, may play a crucial role in the salmon's defense against A. salmonicida. Several related genes were identified, including angptl4, cipcb, grasp, ccr9a, sulf1, mtmr11, B3GNT3, mt2, PLXDC1, and ank1b.