Lung infections are especially hard on patients with cystic fibrosis. Unfortunately, one of the symptoms of the disease is frequent respiratory, lung, and bronchial infections. When a patient has cystic fibrosis it is harder to treat the infection because the bacteria that causes them stick to the thick mucus found in the lungs and air passageways. While they are there they have a good breeding ground to multiply and grow. Mucus also prevents antibiotics from reaching the source of the infection, which makes it even harder to treat.