Mycobacterium tuberculosis and the closely related organism Mycobacterium bovis can
survive and replicate inside macrophages. Intracellular survival is at least in part attributed to
the failure of mycobacterial phagosomes to undergo fusion with lysosomes. The
transformation of phagosomes into phagolysosomes involves gradual acquisition of markers
from the endosomal compartment. Members of the rab family of small GTPases which confer
fusion competence in the endocytic pathway are exchanged sequentially onto the …