GS112-1

Gram – CSF:  polymorphonuclear cells (PMNs) + gram positive bacilli – Shipped August 2011

HISTORY

A smear simulating CSF collected from a 74 year old ER patient with meningitis was sent to laboratories A, B, C, and C1 for Gram staining.

Participants were expected to report the presence of PMNs and gram positive bacilli/coccobacilli.

MAIN EDUCATIONAL POINTS from GS112-1

  1. L. monocytogenes is a gram positive coccobacillus but may also appear as coccoid forms and often is gram variable in older cultures. On Gram stain, it may be hard to differentiate from diphtheroid-like corynebacteria.

Full critique (PDF)

Posted in Clinical Bacteriology Results, critiques, Gram