Mycobacterium smegmatis is an acid-speedy bacterial species in the phylum Actinobacteria and the genus Mycobacterium. it's far 3. zero to 5. zero µm long with a bacillus shape and can be stained through Ziehl-Neelsen approach and the auramine-rhodamine fluorescent method. It became first pronounced in November 1884 by means of Lustgarten, who observed a bacillus with the staining look of tubercle bacilli in syphilitic chancres. after this, Alvarez and Tavel discovered organisms like that described by means of Lustgarten also in regular genital secretions.