The resilience of <i>Salmonella</i> to bile stress is impaired due to the reduced efflux pump activity mediated by the antioxidant enzyme YqhD

Foodborne pathogen <i>Salmonella</i> can tolerate high concentrations of bile and even survive the harsh environment of the gall bladder. This study is significant as it explores the role of a novel antioxidant gene <i>yqhD</i> in bile salt susceptibility of <i>Salmonella</i> Typhimurium and Typhi. It highlights how the presence of gene <i>yqhD</i>, though advantageous in macrophages, reduces the <i>Salmonella</i> survival on bile salt exposure <i>in vitro</i> and in liver cell line HepG2. Deletion of <i>yqhD</i> increased the survival on bile stress exposure, which was attributed to its ability to induce the AcrAB efflux pump of <i>Salmonella</i>. A deeper understanding of how <i>Salmonella</i> modulates gene expression in response to bile stress could provide valuable insights into addressing the chronic carriage of <i>Salmonella</i>.