Mycobacterium flavescens

Mycobacterium flavescens

Etymology: Latin, flavescens = becoming golden yellow.

Description
Gram-positive, nonmotile and acid-fast rods.

Colony characteristics
 * Soft, yellow-orange scotochromogenic, butyrous colonies.

Physiology
 * Slow growth on Löwenstein-Jensen medium at 25-37°C, but not at 45°C within 7-10 days.
 * Although growth rate is intermediate, metabolic and physiologic properties are more like rapidly growing species.

Differential characteristics
 * Serologic specificity demonstrated by immunodiffusion.
 * Related to M. fortuitum: can be distinguished by its intense pigment production, and its slow rate of growth.

Pathogenesis
Not associated with disease. Biosafety level 2.

Type Strain
Strain ATCC 14474 = CCUG 29041 = CIP 104533 = DSM 43991 = JCM 12274 = NCTC 10271 = NRRL B-4038.
 * Normal human flora, environmental habitat.
 * First isolated from a drug treated tuberculous guinea pig (Mexico).