Cover photograph (Copyright © 2015, American Society for Microbiology. All Rights Reserved.): Ring-shaped structure of cyclic β-1,2-glucan (CβG) molecules. The representation was built with fluorescence confocal images of Brucella abortus expressing the membrane enzymatic complex responsible for CβG synthesis, transport, and succinylation. The complex is located mainly at cell poles. (Images taken by Leticia S. Guidolin and Francisco F. Guaimas.) (See related article on page 1640.)