Mycobacterium smegmatis. Mycobacterium smegmatis is an acid-fast bacterial species inside the phylum Actinobacteria and the genus Mycobacterium. it is 3.0 to 5.0 µm lengthy with a bacillus shape and can be stained by means of Ziehl-Neelsen technique and the auramine-rhodamine fluorescent method. while Mycobacterium smegmatis has been developing for quite some time (normally after forty eight hr growth) and is abundant, the shade will flip from white to a nonpigmented creamy yellow. it's going to also be waxy due to the high amount of unique Gram-tremendous mobile wall coated with mycolic acids. As a reason of human ailment, M. smegmatis is 2d to Mycobacterium fortuitum, and can be found in normal human-genital secretions, in addition to in lower animals, soil, dust, and water. Disseminated infections because of M. smegmatis are typically associated with immunosuppression