An electron microscope study of the band structure of the leprosy bacillus and other mycobacteria.

Peculiar band structures were found on murine and human leprosy bacilli in 1958 by Okada (1) _ Consequently Okada postulated that there might be some process of demarcation in the bacillary body which results in replication in a manner different from ordinary cell division. Sato has also presented pictures of similar structures (2) which he termed "demarcation lines" in the leprosy bacillus. In the course of an electron microscopic study of leprosy bacilli obtained from new lepromas of a resistant lepromatous patient, distinct band structures were found in almost all intact bacilli (Figs. 2, 3, 6, and 7) . Subsequently, similar electron microscope examination of leprosy bacilli was repeated on six cases of acute leprous infection in all of which distinct band structures (Figs. 4, 5) were found. It seems probable that these band structures are a constant feature of growing leprosy bacilli.