Cystic fibrosis (CF) is a genetic disorder that affects about 30,000 people in the US (70,000 worldwide). CF causes the body to produce unusually thick, sticky mucus that clogs the lungs and leads to life-threatening lung infections.

The thick mucus caused by CF makes it easy for a common bacterium called Pseudomonas aeruginosa to get trapped in the lungs. For people with CF, Pseudomonas aeruginosa is responsible for most lung infections. Repeated infections can reduce lung function.