Query: NC_012967:531000 Escherichia coli B str. REL606 chromosome, complete genome
Lineage: Escherichia coli; Escherichia; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: Escherichia coli B str. REL606 is unable to use arabinose due to a mutation. This organism was named for its discoverer, Theodore Escherich, and is one of the premier model organisms used in the study of bacterial genetics, physiology, and biochemistry. This enteric organism is typically present in the lower intestine of humans, where it is the dominant facultative anaerobe present, but it is only one minor constituent of the complete intestinal microflora. E. coli, is capable of causing various diseases in its host, especially when they acquire virulence traits. E. coli can cause urinary tract infections, neonatal meningitis, and many different intestinal diseases, usually by attaching to the host cell and introducing toxins that disrupt normal cellular processes.
Subject: NC_008258:3995553 Shigella flexneri 5 str. 8401, complete genome
Lineage: Shigella flexneri; Shigella; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: This genus is named for the Japanese scientist (Shiga) who discovered them in the 1890s. They are closely related to the Escherichia group, and may be considered the same species. Shigella spp. are human-specific pathogens that are transmitted via contaminated food and water and are the leading causes of endemic bacillary dysentery, and over 1 million deaths worldwide are attributed to them. 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 require very few cells in order to cause disease. 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. This organism, along with Shigella sonnei, is the major cause of shigellosis in industrialized countries and is responsible for endemic infections.