22 July 2015
Vol 7, Issue 297

About The Cover

Cover image expansion

ONLINE COVER Already-Formidable Foes Conceal New Weapons. A pair of Pseudomonas aeruginosa bacteria swim innocently across the stage in this colored transmission electron micrograph. But these Gram-negative bugs cause serious intestinal, lung, wound, skin, and urinary tract infections—especially the drug-resistant varieties. Dire warnings in the popular press have brought to the forefront the perils of antibiotic resistance, but the problem might be worse than we thought. In this week's issue, Roux et al. show that in P. aeruginosa and two other pathogenic bacteria—Acinetobacter baumannii and Vibrio cholerae—mutations in genes that confer intrinsic or acquired antibiotic resistance also impart on the bugs both fitness and virulence advantages during infection. These findings add a new wrinkle in the battle against our drug-resistant adversaries. [CREDIT: L. M. STANNARD, UNIVERSITY OF CAPE TOWN/SCIENCE SOURCE]