Query: NC_007799:968499 Ehrlichia chaffeensis str. Arkansas, complete genome
Lineage: Ehrlichia chaffeensis; Ehrlichia; Anaplasmataceae; Rickettsiales; Proteobacteria; Bacteria
General Information: This strain is the first isolate of Ehrlichia chaffeensis, which was obtained from a patient on an army base in Arkansas, USA in 1990. Causes disease in humans. This organism is an obligate intracellular pathogen that exists within vacuoles in the cytoplasm of monocytes or granulocytes. Transferred during an insect (tick) bite, it can cause disease in humans (human monocytic ehrlichiosis) and can reside in several other animals and is a problem in immunocompromised patients. The bacterium inhibits phagosome-lysozome fusion as well as programmed cell death (apoptosis) of the host cell, similar to what is observed with Anaplasma phagocytophilum.
Subject: NC_009881:166500 Rickettsia akari str. Hartford, complete genome
Lineage: Rickettsia akari; Rickettsia; Rickettsiaceae; Rickettsiales; Proteobacteria; Bacteria
General Information: This strain was isolated from mites in Hartford. Causative agent of Rickettsialpox. Members of this genus, like other Rickettsial organisms such as Neorickettsia and Anaplasma, are obligate intracellular pathogens. In both groups, the bacteria are transmitted via an insect, usually a tick, to a host organism where they target endothelial cells and sometimes macrophages. They attach via an adhesin, rickettsial outer membrane protein A, and are internalized where they persist as cytoplasmically free organisms. Rickettsia akari causes a mild disease, Rickettsialpox, which is an acute fever-inducing illness transmitted by a hematophagous mite that infects the common house mouse and bites humans. Infection by this organism may be confused with anthrax due to the black eschar. This bacterium is a member of the spotted fever group of Rickettsiales and is endemic to New York, USA, but is also found in other cities in the USA, Russia, South Korea, and South Africa.