The correct answer which best fits the characteristics in this question is Mycobacterium kansasii.

The correct answer which best fits the characteristics in this question is Mycobacterium kansasii.

The remaining Mycobacterium strains can be elimated as:

Mycobacterium marinum is considered a fast-grower.

Mycobacterium scrofulaceum produce deep-yellow to orange pigmented colonies when grown in the either the light or dark.

Mycobacterium avium grows colonies which are nonpigmented in the light and dark which do not intensify after light exposure.

What is the MOST likely identification of an acid-fast bacillus that demonstrates the following characteristics?

slow growth

cream to tan colored colonies when grown in the dark

development of yellow pigment upon exposure to light