Cover photograph (Copyright © 2016, American Society for Microbiology. All Rights Reserved): Colored scanning electron micrograph of the spirochete Leptospira biflexa, devoid of its outer membrane. The image reveals the intimate contact between the spiral-shaped cell body and the periplasmic flagella. (Micrograph taken by David W. Dorward and colorized by Anita Mora.) (See related article on page 1183.)