Mycobacterium leprae may be a bacterium that reasons leprosy. Leprosy can arise at every age from infancy to aged but is curable wherein treatments can ward off disabilities. It turned into discovered in 1873 by the Norwegian physician Gerhard Armauer Hansen, who became looking for the micro organism in the pores and skin nodules of sufferers with leprosy. It was the first bacterium to be identified as causing ailment in humans. It is an intracellular, pleomorphic, acid-fast, pathogenic bacterium.M. Leprae is an aerobic bacillus (rod-shaped bacterium) with parallel sides and round ends, surrounded through the characteristic waxy coating particular to mycobacteria. In size and form, it closely resembles Mycobacterium tuberculosis. This bacterium often takes place in massive numbers inside the lesions of lepromatous leprosy that are usually grouped together like bundles of cigars or organized in a palisade. Due to its thick waxy coating, M. Leprae stains with a carbol fuchsin in place of with the conventional Gram stain. The lifestyle takes several weeks to mature.