UConn Health immunology researcher Jianbin Ruan uses high tech tools such as cryo-electron microscopy and x-ray crystallography to study how certain pathogens can escape our immune system and cause serious infections and diseases. Shigella bacteria is one of those pathogens that can cause nearly a half million infections in the United States each year. The Shigella infection can cause painful gastrointestinal symptoms that can last for days or even weeks with limited treatment options.