04 July 2003
Vol 301, Issue 5629

About The Cover

Cover image expansion

COVER An E. coli bacterium (purple) inside a pod on the inner surface of a mouse bladder, expressing numerous fibers (orange) that interact with the surrounding matrix. During bladder infections, pathogenic E. coli form biofilms inside superficial bladder cells to subvert host immune defenses. As the biofilms mature, these cells protrude into the bladder lumen, forming the pods. See page 105. [Freeze-fracture electron microscopy image (magnification x30,000): J. Heuser and S. Hultgren]