Rickettsiales

This 1976 transmission electron micrograph (TEM) depicted a hypertrophic peritoneal mesothelial cell of mouse that had been experimentally infected intraperitoneally with Orientia tsutsugamushi rickettsial micro-organisms. In this photomicrograph there were several organisms visible free within the mesothelial cell's cytoplasm.Created: 1976

Etiologic Agents of EhrlichiosesCreated: 1997

This 1978 transmission electron micrograph (TEM) depicted a brain capillary of a mouse that had been experimentally infected intravenously with Orientia tsutsugamushi rickettsial micro-organisms. Revealed by this TEM, was the presence of pericapillary hemorrhage and edema. Several of the O. tsutsugamushi organisms were visible within the cytoplasm of a degenerating capillary endothelial cell.Created: 1978

This photomicrograph of a Gimenez-stained yolk sac smear revealed the presence of Rickettsia rickettsii bacteria, which are the cause of Rocky Mountain spotted fever (RMSF). These bacteria range in size from 0.2 x 0.5 micrometers to 0.3 x 2.0 micrometers. They are difficult to see in tissues by using routine histologic stains, and generally require the use of special staining methods, such as the Gimenez stain used in this case.Created: 1974

This 1978 transmission electron micrograph (TEM) depicted a brain capillary of a mouse that had been experimentally infected intravenously with Orientia tsutsugamushi rickettsial micro-organisms. This photomicrograph revealed three O. tsutsugamushi organisms visible within the cytoplasm of the host endothelial cell.Created: 1978

This photomicrograph of a Gimenez-stained yolk sac smear revealed the presence of Rickettsia rickettsii bacteria, which are the cause of Rocky Mountain spotted fever (RMSF). These bacteria range in size from 0.2 x 0.5 micrometers to 0.3 x 2.0 micrometers. They are difficult to see in tissues by using routine histologic stains, and generally require the use of special staining methods, such as the Gimenez stain used in this case.Created: 1974

This 1978 transmission electron micrograph (TEM) depicted a brain capillary of a mouse that had been experimentally infected intravenously with Orientia tsutsugamushi rickettsial micro-organisms. This TEM revealed that one organism was budding from the luminal surface of a hypertrophic capillary endothelial cell, still covered by a third layer consisting of the host cell's plasma membrane. Others are visible free within the endothelial cell's cytoplasm.Created: 1978

This photomicrograph of a Gimenez-stained yolk sac smear revealed the presence of Rickettsia rickettsii bacteria, which are the cause of Rocky Mountain spotted fever (RMSF). These bacteria range in size from 0.2 x 0.5 micrometers to 0.3 x 2.0 micrometers. They are difficult to see in tissues by using routine histologic stains, and generally require the use of special staining methods, such as the Gimenez stain used in this case.Created: 1974

This 1976 transmission electron micrograph (TEM) depicted a hypertrophic peritoneal mesothelial cell of mouse that had been experimentally infected intraperitoneally with Orientia tsutsugamushi rickettsial micro-organisms. In this TEM, several organisms were visible, free within the host cell's cytoplasm. One O. tsutsugamushi appeared within a phagocytic vacuole, still bearing a third outer membrane layer of probable host cell origin.Created: 1976

This 1976 transmission electron micrograph (TEM) depicted a hypertrophic peritoneal mesothelial cell of mouse that had been experimentally infected intraperitoneally with Orientia tsutsugamushi rickettsial micro-organisms. A disintegrating organism was shown within a host cell's phagocytic vacuole.Created: 1976

This 1976 transmission electron micrograph (TEM) depicted a peritoneal mesothelial cell from a mouse that had been experimentally infected intraperitoneally with Orientia tsutsugamushi rickettsial micro-organisms. Captured here in this TEM was the initiation of the process of phagocytosis being carried out on one of the O. tsutsugamushi micro-organisms.Created: 1976

This 1976 transmission electron micrograph (TEM) depicted peritoneal mesothelial cells from a mouse that had been experimentally infected intraperitoneally with Orientia tsutsugamushi rickettsial micro-organisms. This TEM revealed that the extracellular organisms were covered with a distinct third outer membrane of probable host cell origin.Created: 1976

This 1976 transmission electron micrograph (TEM) depicted a hypertrophic peritoneal mesothelial cell of mouse that had been experimentally infected intraperitoneally with Orientia tsutsugamushi rickettsial micro-organisms. This micrograph showed one organism as it was in the process of budding from the luminal cell surface, still covered by a third layer, consisting of the host cell's plasma membrane. Others are visible free within the host cell's cytoplasm.Created: 1976

This 1976 transmission electron micrograph (TEM) depicted a hypertrophic peritoneal mesothelial cell of mouse that had been experimentally infected intraperitoneally with Orientia tsutsugamushi rickettsial micro-organisms. This particular photomicrograph revealed that there were multiple organisms free within the host cell's cytoplasm.Created: 1978

This 1978 transmission electron micrograph (TEM) depicted a brain capillary of mouse that had been experimentally infected intravenously with Orientia tsutsugamushi rickettsial micro-organisms. This photomicrograph revealed that the capillary lumen was partially occluded by a thrombus, and a hypertrophic, degenerating, apparently detached endothelial cell containing several visible organisms free within its cytoplasm.Created: 1978

This 1978 transmission electron micrograph (TEM) depicted a brain capillary of mouse that had been experimentally infected intravenously with Orientia tsutsugamushi rickettsial micro-organisms. In this micrographic view revealed pericapillary edema, the capillary lumen was partially occluded by a thrombus, and flanking the thrombus, a hypertrophic endothelial cell containing a visible organism free within its cytoplasm.Created: 1978

This 1978 transmission electron micrograph (TEM) depicted a brain capillary of mouse that had been experimentally infected intravenously with Orientia tsutsugamushi rickettsial micro-organisms. In this micrographic view, a host cell endothelial cell was shown to contain many organisms free within its cytoplasm.Created: 1978

This 1976 transmission electron micrograph (TEM) depicted a hypertrophic peritoneal mesothelial cell of mouse that had been experimentally infected intravenously with Orientia tsutsugamushi rickettsial micro-organisms. This micrograph captured a dividing organism while it was visible free within the host cell's cytoplasm.Created: 1976

This 1976 transmission electron micrograph (TEM) depicted a hypertrophic peritoneal mesothelial cell from mouse that had been experimentally infected intraperitoneally with Orientia tsutsugamushi rickettsial micro-organisms. This micrograph captured an organism as it appeared within a phagocytic vacuole. An outer third membrane, of probable host cell origin, was disintegrating, leaving behind only its electron-dense remnants.Created: 1976

This 1976 transmission electron micrograph (TEM) depicted a hypertrophic peritoneal mesothelial cell from a mouse that had been experimentally infected intraperitoneally with Orientia tsutsugamushi rickettsial micro-organisms. This micrograph captured an organism as it appeared within a phagocytic vacuole, still bearing a third outer membrane layer of probable host cell origin.Created: 1976

This 1976 transmission electron micrograph (TEM) depicted a peritoneal mesothelial cell from a mouse that had been experimentally infected intraperitoneally with Orientia tsutsugamushi rickettsial micro-organisms. In this particular field of view, an organism was photographically captured as it was budding from the luminal cell surface, while still covered by a third layer consisting of the host cell's plasma membrane.Created: 1976

This 1978 transmission electron micrograph (TEM) depicted a brain capillary of mouse that had been experimentally infected intravenously with Orientia tsutsugamushi rickettsial micro-organisms. In this particular field of view, a hypertrophic capillary endothelial cell contained one visible organism free within its cytoplasm. The adjacent endothelial cell was of normal thickness.Created: 1978

This 1976 transmission electron micrograph (TEM) depicted a brain capillary of a mouse that had been experimentally infected intravenously with Orientia tsutsugamushi rickettsial micro-organisms. Adhering to the luminal surface of the capillary's endothelium was a large macrophage containing multiple organisms free within its cytoplasm.Created: 1978

This 1976 transmission electron micrograph (TEM) depicted an extracellular Orientia tsutsugamushi rickettsial micro-organism, covered with a distinct third outer membrane of probable host mesothelial cell origin. The specimen from which this image was obtained, was extracted from the peritoneal cavity of experimentally infected mouse.Created: 1976