Microbe Magazine

Cover: Phase contrast micrograph of a Clostridium difficile mutant that cannot efficiently import oligopeptides and sporulates at a higher frequency in response. C. difficile, a gastrointestinal pathogen of humans and other animals, is a strict anaerobe and forms a dormant spore allowing survival outside of the host (see p. 153). Spore formation in many bacteria is triggered by nutritional starvation. (Image courtesy of Adrianne N. Edwards, Christopher E. O'Brien, and Shonna M. McBride.)