Mycobacterium duvalii 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. Description Gram-positive, nonmotile and pleomorphic acid-fast rods. Colony characteristics Bright yellow pigmented, scotochromogenic and rough or smooth colonies on Löwenstein–Jensen medium. Physiology Fast growth on Löwenstein–Jensen medium at 25 °C and 37 °C within 7 days. No growth at 45 °C. Resistant to isoniazid, rifampicin, and sodium aminosalicylate. Differential characteristics Characterised by the possession of 6 species-specific antigens demonstrable in immunodiffusion tests. Pathogenicity. Pathogenesis Not pathogenic, but evidence insufficient. Biosafety level 1. Type strain First isolated from cases of human leprosy by C. W. Duval. Strain ATCC 43910 = CCUG 41352 = CIP 104539 = DSM 44244 = JCM 6396 = NCTC 358. References Stanford, J. et al. 1971. A study of some fast-growing scotochromogenic mycobacteria including species descriptions of Mycobacterium gilvum (new species) and Mycobacterium duvalii (new species). British Journal of Experimental Pathology, 52, 627–637.] External links Type strain of Mycobacterium duvalii at BacDive - the Bacterial Diversity Metadatabase Acid-fast bacilli duvalii Bacteria described in 1971