M. avium intracellulare is: September 2009
High-Yield Explanation
Ans. A: Non photochromogens Runyon Groups * Pigmentation studies - Scotochromogens: Pigmentation in the dark (and light) - Photochromogens: Pigmentation only after exposure to light - Non-photochromogens: No pigment forms Group I: photochromogens - Mycobacterium kansasii - Mycobacterium marinum Group II: scotochromogens - Mycobacterium scrofulaceium - Mycobacterium gordonae Group III: non-photochromogens - Mycobacterium avium complex Group IV: Rapid growers - Mycobacterium fouitum - Mycobacterium chelonei