An elderly patient with no recent hospitalizations presents with shortness of breath, chest pain, a deep productive cough, and evidence of consolidation. Acid- fast and Gram stains are performed on a sputum sample. No acid- fast bacteria are detected but Gram- negative, non- encapsulated bacteria are observed. A likely diagnosis is

Question

Quizplus · Accepted Answer

The correct diagnosis is nontypable Hemophilus influenzae B, as it is a Gram-negative, non-encapsulated bacterium that can cause respiratory infections, particularly in elderly patients. Streptococcus pneumoniae is Gram-positive, Mycobacterium avium would be acid-fast, and Legionnaire's disease is caused by Legionella pneumophila, which requires special culture conditions and is not typically seen on a Gram stain. Influenza is caused by a virus, not a bacterium.

An Elderly Patient with No Recent Hospitalizations Presents with Shortness