A sputum specimen submitted for bacterial culture of community-acquired pneumonia is examined under low power. Which finding indicates the specimen is acceptable for culture?

• A More than 25 squamous epithelial cells per low power field
• B Presence of Candida pseudohyphae regardless of cell counts
• C Equal numbers of epithelial cells and neutrophils
• D Fewer than 10 squamous epithelial cells per low power field with abundant neutrophils ✓

Explanation

Specimen quality screening uses the ratio of polymorphonuclear cells to squamous epithelial cells. Fewer than 10 squamous epithelial cells per low power field indicates minimal oropharyngeal contamination, and abundant neutrophils indicate an inflammatory lower airway sample. More than 25 epithelial cells per low power field marks saliva and warrants rejection, which makes option A the rejection criterion. Candida is commonly an oral coloniser and does not validate a specimen.

Reference: Bailey & Scott's Diagnostic Microbiology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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