Q. A 58-year-old man with a history of poorly controlled diabetes mellitus and alcoholism presents to the emergency department with a 5-day history of high-grade fever, cough with purulent sputum, and shortness of breath. His vital signs are: temperature 101.3°F (38.5°C), blood pressure 125/75 mmHg, heart rate 110 beats/min, respiratory rate 24 breaths/min, and oxygen saturation 92% on room air. Physical examination reveals dullness to percussion and crackles in the right lower lung field. A chest X-ray demonstrates consolidation in the right lower lobe. Sputum Gram stain shows short, plump gram-negative bacilli with clear capsules. Which organism is the most likely cause of this patient's pneumonia?