A Proposal of the New Sub-type of Mycobacterium leprae

Abstract

A new sub-type of Mycobacterium leprae was found in our laboratory, and its characteristic is described.
The detailed characteristics were obtained as follows: Gram positive. Acid-fast staining positive. Kirchner, Dubos and Ogawa medium: No growth. Glycerol agar containing heat-killed Mycobacterium phlei: No growth. Rods in tissues of the mouse foot-pad: Average 3 to 5 microns in length, over 5 micron long are ocassionally seen. The bacilli were often formed rounded clump (globi). These findings did not changed until the 6 times passage in the mouse foot-pad.
Souce: Found in lepromatous (nodular) case of leprosy in Japan.
This is confirmed as Mycobacterium leprae: Bacteriological identification depends on; (a) acid-fast staining positive, (b) failure of the organism to multiply in bacteriological media, (c) positive of a limited multiplication in the mouse foot-pad (d) the heat-killed cells produce lepromin reactions in guinea pig, as described elsewhere.^1-2)
Distinctive characters: The length of this organism is longer than that of the other strains of M. leprae
This organism is closely related to Mycobacterium leprae, but differs from morphological size, so that Mycobacterium leprae sub-type (Urashima strain) is proposed.