Abstract
The DNA of 25 strains of leprosy-derived corynebacteria (LDC).sbd.non-acid-fast, gram-positive bacteria independently isolated from human leprosy lesions and propagated in axenic culture.sbd.were purified and analyzed. The guanine plus cytosine content, by buoyant density determination, was 54-59 mol% for most LDC strains, a range that corresponds to that (50-60 mol%) of corynebacteria which multiply in animal cells. These values were checked by chromatographic analyses of acid digests of the DNA. The taxonomic position of the LDC as determined by DNA base composition was confirmed by the results of the corynomycolic acid determinations of the cell walls of the LDC. The results of the hydridization of the DNA from the LDC strains suggest the occurrence of 2 high-homology groups, in which most of the strains were accommodated. In contrast, little homology was observed between the DNA of the LDC and the reference corynebacteria employed. It can be inferred that the LDC represent a homogeneous and unique cluster of organisms within the genus Corynebacterium, more specifically within the group of corynebacteria pathogenic for humans.