Query: NC_009879:107890 Rickettsia canadensis str. McKiel, complete genome
Lineage: Rickettsia canadensis; Rickettsia; Rickettsiaceae; Rickettsiales; Proteobacteria; Bacteria
General Information: This organism was originally isolated from ticks in a field study on tick-transmitted diseases of small mammals in Canada. Member of the typhus group of Rickettsiales. 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 canadensis was originally thought to be a member of the typhus group of Rickettsiales, however, it is now thought to represent a distict group with the rickettsia.
Subject: NC_007613:2699500 Shigella boydii Sb227, complete genome
Lineage: Shigella boydii; Shigella; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: This strain is an isolate from an epidemic that took place in China in the 1950s. Causes dysentery. This genus is named for the Japanese scientist (Shiga) who first discovered these organisms in the 1890s. They are closely related to the Escherichia group, and may be considered the same species. These organisms are human-specific pathogens that are transmitted via contaminated food and water and are the leading causes of endemic bacillary dysentery, causing over 160 million cases of infection and 1 million deaths yearly worldwide. The bacteria infect the epithelial lining of the colon, causing acute inflammation by entering the host cell cytoplasm and spreading intercellularly. are extremely virulent organisms that can cause an active infection after a very low exposure. Both the type III secretion system, which delivers effector molecules into the host cell, and some of the translocated effectors such as the invasion plasmid antigens (Ipas), are encoded on the plasmid. The bacterium produces a surface protein that localizes to one pole of the cell (IcsA) which binds to and promotes actin polymerization, resulting in movement of the bacterium through the cell cytoplasm, and eventually to neighboring cells, which results in inflammatory destruction of the mucosal lining. Shigella boydii is uncommon except in India, where it was first isolated. Progression to clinical dysentery occurs in most patients infected with this organism.