Gram stain: positive Cell shape: bacillus Arrangement: single Oxygen requirements: Other: these organisms are acid fast.
Habitat: soil, plants, animals
Pathogenicity: This organism is the cuasative agent of tuberculosis, so named because of the tubercles it forms to avoid host defense mechanisms. It is increasing in incidence worldwide, especially in areas of overcrowding and poor sanitation. Resistant strains have developed and TB remains the leading killer of the world's infectious diseses with at least one-third of the world's population infected!
Transmission: airborne; you only need as many as 30 cells to colonize a host.
Diagnosis: thru the Mantoux or PPD skin test and confirmed with a chest x-ray.
Treatment: Immunity can be conferred by the BCG vaccine although this is not commonly used in the United States. Common treatment for a positive skin test is Isonazid or Rifampin for one year, supplemented with streptomycin.
This organism has been used for treatment of bladder cancer for several decades. The exact mechanism is not understood, but the organism binds to cancerous cells and renders them harmless. Only a slight percentage of patients end up with TB as a result and are then treated before the condition becomes active.
Mycobacterium tuberculosis
