Salmonella species cause a variety of diseases, including diarrheal and systemic illness, signicificant causes of morbidity and mortality in the developing and developed world. To cause disease in healthy people, bacteria such as Salmonella typhimurium must first breach physical barriers, such as the mucous membrane lining internal organs, and then successfully avoid detection and destruction by the immune system. Gastroenteritis (inflammation of the stomach and intestine) in healthy humans and systemic illness in people with compromised immune systems result from the successful evasion of Salmonella typhimurium. Resistance to infection depends on a wide array of immune factors. Bryan Coburn is researching the role of host resistance factors and also the response of bacteria to these defenses in Salmonella-induced gastroenteritis. The research will potentially provide important insights about the mechanisms that influence susceptibility or resistance to Salmonella-induced gastroenteritis.