TABLE 1.

Intracellular microorganisms surviving within phagocytic cells

Site of multiplication and pathogen	Intracellular behavior	Target cells	pHa	Reference(s)
Cytosol without PLFb
Rickettsia spp.	Strict	Endothelial cells	∼6.5	44, 163
Shigella spp.	Facultative	Various	∼6.5	128, 147
Cytosol after PLF
L. monocytogenes	Facultative	Various	∼6.5	94, 100
Unfused vacuole
L. pneumophila	Facultative	MPs	5.7–6.5	87
Toxoplasma gondii	Facultative	MPs	6.8–7.0	155
Selectively fused vacuole
Chlamydia spp.	Strict	Epithelial cells	>6.0	82
M. tuberculosis	Facultative	MPs	NDc	37, 168
Mycobacterium avium	Facultative	MPs	6.3–6.5	37, 168
Mycobacterium marinum	Facultative	MPs	6.3–6.5	15
Salmonella spp.	Facultative	MPs	<7.0	138
Uncharacterized endosome
Ehrlichia chaffeensis	Strict	Monocytes	ND	16
HGE agent	Strict	PMNs	ND	75
Brucella spp.	Facultative	MPs	ND	66
Bartonella spp.	Facultative	Endothelial cells	ND	26, 42, 72, 73
Afipia felis	Facultative	ND	ND	25
Yersinia enterocolitica	Facultative	MPs	ND	175
Mycobacterium leprae	Strict	MPs	ND	65, 154
Nocardia asteroides	Facultative	MPs	ND	19
Acidic phagolysosome
C. burnetii	Strict	MPs	4.7	4, 78, 113
Leishmania donovani	Facultative	MPs	5.2	7
S. aureus	Facultative	MPs, PMNs	4.8	102, 117
Alkalinized phagolysosome
Histoplasma capsulatum	Facultative	MPs	∼7.0	53

^apH of the intracellular multiplication site. 

^bPLF, phagosome-lysosome fusion. 

^cND, not determined.