Nocardia

Michael Melia, M.D., John G. Bartlett, M.D.
Nocardia is a topic covered in the Johns Hopkins ABX Guide.

To view the entire topic, please or .

Official website of the Johns Hopkins Antibiotic (ABX), HIV, Diabetes, and Psychiatry Guides, powered by Unbound Medicine. Johns Hopkins Guide App for iOS, iPhone, iPad, and Android included. Explore these free sample topics:

-- The first section of this topic is shown below --

MICROBIOLOGY

  • Gram-positive branching, beaded, filamentous rod.
    • Partially acid fast with modified Kinyoun stain.
    • Can be difficult to recover; notify lab if high index of suspicion.
    • Grow on non-selective media in 2-14 days.
      • Selective media (Thayer-Martin, paraffin agar, charcoal-buffered yeast extract media) may be needed to enhance growth and minimize contaminants.
  • More than 50 species known. Found worldwide, considered a soil pathogen. May also be seen in human oral flora.
    • Many of the isolates initially identified as N. asteroides are now known by modern techniques to have been misclassified.
  • Classified by some according to drug-susceptibility patterns + other organisms/groups:
    • Type I: N. abscessus
    • Type II: N. brevicatena/paucivorans complex
    • Type III: N. nova complex (including N. nova, N. veterana, N. africana)
    • Type IV: N. transvalensis complex
    • Type V: N. farcinica
      • Most common cause of disseminated/extrapulmonary disease
    • Type VI: N. cyriacigeorgica
    • N. brasiliensis
      • Cause of primary cutaneous infection in immunocompetent hosts
    • N. pseudobrasiliensis 
    • N. otitidiscaviarum 

-- To view the remaining sections of this topic, please or --

MICROBIOLOGY

  • Gram-positive branching, beaded, filamentous rod.
    • Partially acid fast with modified Kinyoun stain.
    • Can be difficult to recover; notify lab if high index of suspicion.
    • Grow on non-selective media in 2-14 days.
      • Selective media (Thayer-Martin, paraffin agar, charcoal-buffered yeast extract media) may be needed to enhance growth and minimize contaminants.
  • More than 50 species known. Found worldwide, considered a soil pathogen. May also be seen in human oral flora.
    • Many of the isolates initially identified as N. asteroides are now known by modern techniques to have been misclassified.
  • Classified by some according to drug-susceptibility patterns + other organisms/groups:
    • Type I: N. abscessus
    • Type II: N. brevicatena/paucivorans complex
    • Type III: N. nova complex (including N. nova, N. veterana, N. africana)
    • Type IV: N. transvalensis complex
    • Type V: N. farcinica
      • Most common cause of disseminated/extrapulmonary disease
    • Type VI: N. cyriacigeorgica
    • N. brasiliensis
      • Cause of primary cutaneous infection in immunocompetent hosts
    • N. pseudobrasiliensis 
    • N. otitidiscaviarum 

There's more to see -- the rest of this topic is available only to subscribers.

Last updated: July 30, 2017