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_009900:180970 Rickettsia massiliae MTU5, complete genome
Lineage: Rickettsia massiliae; Rickettsia; Rickettsiaceae; Rickettsiales; Proteobacteria; Bacteria
General Information: Rickettsia massiliae MTU5 was isolated from the tick Rhipicephalus turanicus collected from horses in Le Sambuc, Bouches-du Rhone, France. 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 massiliae is a member of the spotted fever group of the Rickettsiales and has been isolated from ticks in Europe and Africa. Rickettsia massiliae does not appear to cause disease in humans.