Mycobacterium flavescens is a species of the phylum Actinomycetota (Gram-positive bacteria with high guanine and cytosine content, one of the dominant phyla of all bacteria), belonging to the genus Mycobacterium. Etymology Its name is derived from the Latin word "flavescens", which means "becoming golden yellow." Description Gram-positive, nonmotile and acid-fast rods. Colony characteristics Rough, 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 Mycobacterium 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 Normal human flora, environmental habitat. First isolated from a drug treated tuberculous guinea pig (Mexico). Strain ATCC 14474 = CCUG 29041 = CIP 104533 = DSM 43991 = JCM 12274 = NCTC 10271 = NRRL B-4038. References Bojalil et al. 1962. Adansonian classification of mycobacteria. Journal of General Microbiology, 28, 333–346.] External links Type strain of Mycobacterium flavescens at BacDive - the Bacterial Diversity Metadatabase Acid-fast bacilli flavescens Bacteria described in 1962