A 3 year old child with cystic fibrosis presents with weight loss, irritability, and a chronic productive cough. On physical exam, he is febrile and lung exam reveals intercostal retractions, wheezing, rhonchi, and rales. Chest x-ray demonstrates patchy infiltrates and atelectasis and Gram's stain of the sputum reveals slightly curved, motile gram-negative rods that grow aerobically. The microorganism responsible for this child's pneumonia is also the most common cause of which of the following diseases?