Gram Stain

Microbiology

Normal Reference Ranges

Adult

No organisms seen Qualitative

Pediatric

No organisms seen Qualitative

Clinical Significance

Provides rapid, immediate preliminary classification of bacteria to guide empiric antibiotic therapy while awaiting formal cultures.

Causes of High

  • Bacterial infection (e.g., Gram Positive Cocci in clusters = Staph; Gram Negative Rods = E.coli)

Causes of Low

  • Normal finding
  • Atypical bacteria (Mycoplasma, Legionella)