Gram – Sputum: >25/lpf neutrophils, 0-2/lpf epithelial cells – 3+ (11-50/oif) gram negative coccobacilli (Haemophilus influenzae) and 3+ (11-50/oif) gram positive cocci (Streptococcus viridans group). Sample suitable for culture – Shipped November 06, 2017


A simulated sputum sample collected from a 64 year old smoker was sent to category A, B, C, and C1 laboratories.

Participants were expected to report the presence of neutrophils, epithelial cells, gram negative coccobacilli and gram positive cocci. Participants were also expected to indicate the sample was suitable for culture.


  1. The Gram stain can provide clinicians with useful information about the quality of a sputum sample, and hence the reliability of the culture, and the possible causative agents of infection.
  2. When the Gram stain morphology of organisms is fairly predictive of their identity, that information, or at least an accurate description, is useful to provide in the report.

Full critique (PDF)

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