mycobacterium duvalii mycobacterium duvalii 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. mycobacterium duvalii scientific classification domain: bacteria phylum: actinomycetota class: actinomycetia order: mycobacteriales family: mycobacteriaceae genus: mycobacterium species: m. duvalii binomial name mycobacterium duvaliistanford and gunthorpe 1971, atcc 51304 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.