II. Test Sensitivity: Gram Stain

  1. Factors improving sensitivity
    1. Centrifugation
    2. Experienced technician
  2. Bacterial Meningitis
    1. Overall
      1. Untreated cases: Up to 80%
      2. Treated cases: Up to 60%
    2. Organism concentration
      1. Colony forming units (CFU) <1000/mm3: 25%
      2. Colony forming units (CFU) >100,000/mm3: 75%
    3. Organism specific
      1. Streptococcus Pneumoniae: 90%
      2. Listeria monocytogenes: 50%

III. Preparations: Special stains

  1. Acid Fast Stain: Tuberculosis
  2. India Ink: Cryptococcus (tap water control required)
  3. Wright or Giemsa stain: Toxoplasmosis
  4. Saline mount: Protozoa

IV. References

  1. Kooiker in Roberts (1998) Procedures in ER, p. 1067-75
  2. Ravel (1995) Lab Medicine, Mosby, p. 294-9
  3. Tunkel in Mandell (2000) Infectious Disease, p. 974-8
  4. Seehusen (2003) Am Fam Physician 68:1103-8 [PubMed]

Images: Related links to external sites (from Bing)

Related Studies