Abstract:Indole is widespread in the natural environment, as more than 145 Gram-positive and Gram-negative bacteria can produce indole, including many pathogenic bacteria. More and more mechanism studies have revealed that indole acts as an important intercellular signal molecule in some enteric pathogens such as Escherichia coli, Edwardsiella tarda and Vibrio cholera, and controls diverse aspects of bacterial physiology, such as virulence, drug resistance, biofilm formation, motility, plasmid stability, acid resistance and spore formation. More importantly, indole and its derivatives regulate competition of microbial consortia and benefit digestive and immune system in human. We discuss our current study on the role of indole signaling in Edwardsiella tarda and review the progress of study on indole signaling in diverse bacterial species. Thus, better understanding of the indole signaling mechanism will help to develop new anti-infection strategies and their biotechnology applications.