Gene Expression Responses to Infection with Avian Pathogenic Escherichia coli in Chicken Spleen

Mortality and other production losses due to infection with avian pathogenic Escherichia coli (APEC) are a worldwide problem for the poultry industry. In this study, changes in gene expression during APEC infection were characterized in the chicken spleen using RNA-sequencing. Over 400 genes had significant expression changes in response to APEC, with greater changes at 1 day post infection (DPI) than 2 DPI. This decrease was consistent with bacterial clearance from the spleen. Immune signaling, complement, and antimicrobial genes (such as AVD and IL22) were highly upregulated in response to APEC and predicted to increase phagocyte migration and leukocyte activation. These pathways could contribute to chicken resistance to APEC and provide targets for future research