• Pathophysiology
  • Characteristics
  1. Rod shaped Bacteria
  2. Obligate aerobic Bacteria
    1. Hence predisposition for the lungs (e.g. Tuberculosis)
  3. Acid fast organisms due to lipid rich cell walls
    1. Acid Fast Staining is unique to Mycobacteria and Nocardia
  4. Mycobacteria grow slowly in culture (up to 6 weeks)
    1. Many Mycobacterial species grow in clumps due to their hydrophobic, lipid rich cell walls
  • Types
  1. Tuberculous Mycobacteria
    1. Mycobacterium tuberculosis
    2. Mycobacterium leprae (Leprosy, Hansen's Bacillus)
    3. Mycobacterium Bovis
      1. Primarily infects cattle, but may also cause Tuberculosis in humans
      2. Transmitted in unpasteurized milk or dairy products from infected cattle
      3. May also transmitted by airborne Bacteria from infected animals
      4. May also spread by direct contact during meat processing
  2. Non-Tuberculous Mycobacteria
    1. Background
      1. Ubiquitous Bacteria found in soil and water
      2. Healthy patients are frequently exposed but rarely infected
    2. Mycobacterium Avium Complex (MAC)
      1. AIDS defining disease
      2. May also less commonly infect lungs in immunocompetent patients
    3. Mycobacterium Abscessus
      1. May affect lung, skin, soft tissue and bone
    4. Mycobacterium Chelonae
      1. May affect skin, soft tissue and bone
      2. May cause Keratitis in Contact Lens users
      3. May cause disseminated infection in Immunocompromised patients
    5. Mycobacterium Fortuitum
      1. May affect skin, soft tissue and bone
    6. Mycobacterium Marinum (Fish Tank Granuloma)
      1. Nodular Lymphangitis in those caring for fish tanks
    7. Mycobacterium Scrofulaceum
      1. Found in house dust, soil, water, and sewage as well as unpasteurized milk
      2. May cause Cervical Lymphadenopathy in children
    8. Mycobacterium Ulcerans ("Buruli Ulcers")
      1. Progressive necrotic Skin Ulcers
  • References
  1. Gladwin, Trattler and Mahan (2014) Clinical Microbiology, Medmaster, Fl, p. 142-155