Bacterial obligate intracellular parasites have evolved diverse mechan
isms for evasion of host cellular defenses. These mechanisms involve a
daptations for survival in distinct intracellular compartments. Intrac
ellular niches inhabited by obligate intracellular parasites include t
he cytoplasm, arrested early endosomes, lysosomes, and vesicles that d
o not fuse with the endosomal compartment but intersect with an exocyt
ic pathway.