Many infectious pathogens are difficult to treat because they develop into biofilms, layers of metabolically active but slowly growing bacteria embedded in a protective layer of slime, which are inherently more resistant to antibiotics. Now, a group of researchers at Caltech and the University of Oxford have made progress in the fight against biofilms. Led by Dianne Newman, the Gordon M. Binder/Amgen Professor of Biology and Geobiology, the group identified a protein that degrades and inhibits biofilms of Pseudomonas aeruginosa, the primary pathogen in cystic fibrosis (CF) infections.