system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Gram staining of the sputum of the patients with pneumonia is diagnostic with all these pathogens, EXCEPT:
assistant
The correct answer is  Gram's staining may identify ceain pathogens (e.g., S. pneumoniae, S. aureus, and gram-negative bacteria) by their characteristic appearance. A sputum sample must have 1. >25 neutrophils 2. <10 squamous epithelial cells per low-power field, to be adequate for culture. Ref: Harrison, E-18, P-2133