Aspiration pneumonia is not considered a distinct entity, and robust diagnostic criteria are lacking (1). The diagnosis of aspiration pneumonia depends on a characteristic clinical history (witnessed macroaspiration), the presence of risk factors, and typical findings on chest radiography (1). The radiographic findings include infiltrates in gravity-dependent lung segments (Picture A: 90-year-old woman, Picture C: 79-year-old man). Both of these patients showed typical radiological features and a clinical history of aspiration pneumonia. Aspiration pneumonia is well known to be caused by polyclonal microorganisms, including oral aerobic and anaerobic bacteria. However, the Gram stain (Picture B: 90-year-old woman, Picture D: 79-year-old man) and sputum culture of the present patients demonstrated a monoclonal growth of Streptococcus pneumoniae as the causative organism. The contrasting radiological and Gram stain findings may be explained by the recent concept suggesting initial colonization of S. pneumoniae in the airway (2), followed by aspiration into the alveoli, leading to pneumonia.
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The authors state that they have no Conflict of Interest (COI).
References
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