Gram – Pleural fluid: neutrophils – gram negative coccobacilli


A simulated pleural fluid smear collected from a 40 year old ICU patient with chest pain was sent to category A, B, C, and C1 laboratories.

Participants were expected to report the presence of neutrophils and gram negative coccobacilli.


  1. Accurate reading and interpretation of Gram stains as well as the prompt reporting of results are very important to initiate appropriate treatment while waiting for culture results.
  2. Empyema is defined by the presence of pus or bacteria in the pleural space. As much as 60% are associated with pneumonia, and approximately 40% may be secondary to other processes that are non-pneumonic.
  3. Whereas the most common pathogens associated with community acquired pneumonia include Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus, as much as 50% of parapneumonic infections are due to streptococcal species, most commonly S. intermedius, followed by S. pneumoniae.


Full critique (PDF)

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