Mycobacterium tuberculosis, one of the most prevalent causes of death worldwide, is a
facultative intracellular parasite that invades and persists within the macrophages. Within
host cells, the bacterium is surrounded by a capsule which is electron-transparent in EM
sections, outside the bacterial wall and plasma membrane. Although conventional
processing of samples for microscopy studies failed to demonstrate this structure around in
vitro-grown bacilli, the application of new microscopy techniques to mycobacteria allows the …