Ultrastructural changes in bacteria isolated from cases of leprosy.

One of two groups of rod-shaped bacteria (bacilli) isolated from cases of human leprosy have been found, under certain cultural conditions, to give rise to unusual phenotypes. In electron micrographs of ultrathin sections and negatively stained whole cells of these osmotically fragile bacteria, ultrastructural anomalies are apparent and seem to arise from disorder in the process(es) of septum formation or cell envelope biosynthesis or both. Two of the four strains examined are related to Corynebacterium acnes.