Electron Microscopy of Listeria monocytogenes-Infected Mouse Spleen

Armstrong, B. A. (The University of Kansas, Lawrence), andC. P. Sword. Electron microscopy of Listeria monocytogenes-infected mouse spleen. J. Bacteriol. 91:1346–1355. 1966.—Mouse spleen infected with Listeria monocytogeneswas observed during the acute phase of infection; 72 hr after infection, organisms were usually found within phagocytic vacuoles in the cytoplasm of macrophages. These vacuoles, which resembled phagosomes, often contained several organisms as well as varying amounts of amorphous electron-dense material, ferritin-like particles, membrane fragments, and vesicles of varying density. Breakdown of vacuolar membranes appeared to be accompanied by damage to the host cell cytoplasm. Nuclear membrane damage was occasionally observed when phagocytic vacuoles were close to the nucleus.