An 88-year-old woman is brought to the clinic by nursing home facility personnel for follow up after a recent hospitalization. She was being treated for a poorly healing wound on the medial side of her right fifth metatarsal-phalangeal joint. She has had a cough for the past 3 days. She has a history of severe dementia, type 2 diabetes, and aspiration pneumonia. She has received 3 courses of intravenous antibiotics in the past 6 months. She is admitted to the hospital and sputum culture is obtained. The sputum culture grows Klebsiella pneumoniae.
Which of the following best describes Klebsiella pneumoniae?
The correct answer is:
A) A gram-negative, encapsulated rod that is resistant to extended spectrum beta-lactams (ESBLs) that is found with other organisms
This describes a Klebsiella pneumonia. Aspiration pneumonia is often polymicrobial, and this patient’s sputum culture establishes the diagnosis of Klebsiella pneumonia.
Answer choice B: A gram-negative rod living in amoebae, with alveolar fibrinopurulent exudate, is incorrect. This describes a Legionella pneumonia.
Answer choice C: A gram-positive coccus in clusters which is resistant to methicillin and that may give rise to pneumatoceles, is incorrect. This describes a Staphylococcus aureus pneumonia.
Answer Choice D: An acid-fast bacillus with Ghon complexes, is incorrect. This describes tuberculosis.
Answer Choice E: An obligate intracellular bacterium with a biphasic life cycle that creates inflammation primarily in the interstitium, is incorrect. This describes a Chlamydia pneumonia.
Key Learning Point
Identifying the likely etiology of a pneumonia based on clinical setting, anatomic distribution, and the nature of the host reaction is high yield. Klebsiella pneumonia is associated with aspiration, particularly in a nosocomial setting.
