The degradation of Mycobacterium leprae by a comparison of its staining properties.

The disintegration of Mycobacterium leprae is revealed by a study of its acid-fast component, its non-acid-fast cell walls using methenamine silver, and its BCG-positive cytoplasmic component. Solid bacilli stain by the three stain techniques used to identify these products, but the BCG component is demonstrated only with difficulty and appears granular. Degradation of M. leprae is fairly rapid in BT, BB, and BL, and clearance of bacillary products occurs almost simultaneously because of the destruction of the cell walls. However, clearance is slower in nerves and BCG-positive material persists. The breakdown of cell walls is slow in LL and their clearance is delayed, but BCG-positive material is cleared as fast as it leaks out. ENL appears to coincide with a more rapid breakdown and release of disintegration products from degenerate macrophages. The Mitsuda reaction appears as an epithelioid cell granuloma after complete degradation of M. leprae with residual BCG positive material at 30 days.