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

<i>Aeromonas salmonicida</i> 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 <i>Salmo trutta</i> aquaculture. In recent years, the outbreak of Bacterial Gill Disease (BGD) has led to substantial economic losses for <i>S. trutta</i> farmers. Our prior research identified <i>A. salmonicida</i> as one of the primary culprits behind BGD. To mitigate the impact of <i>A. salmonicida</i> on <i>S. trutta</i>, we conducted a comprehensive study aimed at identifying genes associated with resistance to <i>A. salmonicida</i>. This involved transcriptome sequencing and 16S rRNA sequencing of intestinal flora, providing valuable insights for the study of disease resistance in <i>S. trutta</i>. 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, <i>Methylobacterium</i> and <i>Sphingomonas</i> were common bacteria present in the salmon's gut, and their proportions remained relatively stable before and after infection. <i>Shewanella</i>, with its antagonistic relationship with Aeromonas, may play a crucial role in the salmon's defense against <i>A. salmonicida</i>. Several related genes were identified, including <i>angptl4</i>, <i>cipcb</i>, <i>grasp</i>, <i>ccr9a</i>, <i>sulf1</i>, <i>mtmr11</i>, <i>B3GNT3</i>, <i>mt2</i>, <i>PLXDC1</i>, and <i>ank1b</i>.