Microbiology Staining Drill

Reference: Microbiology Stains

1. Organisms Poorly Visualized on Gram Stain

Mnemonic: "These Little Microbes May Unfortunately Lack Real Color But Are Everywhere"

• Treponema (too thin to be seen)
• Legionella (primarily intracellular)
• Mycobacteria (high lipid cell wall; mycolic acid)
• Mycoplasma (no cell wall)
• Ureaplasma (no cell wall)
• Listeria (Gram-positive, but sometimes tricky)
• Rickettsia (intracellular)
• Chlamydia (intracellular; lacks classic peptidoglycan)
• Bartonella (intracellular)
• Anaplasma (intracellular)
• Ehrlichia (intracellular)

2. Special Stains