Query: NC_006570:24636 Francisella tularensis subsp. tularensis Schu 4, complete genome
Lineage: Francisella tularensis; Francisella; Francisellaceae; Thiotrichales; Proteobacteria; Bacteria
General Information: This subspecies is virulent in humans, and the strain is a clinical isolate that is also virulent in an animal model. Originally isolated from a human case of tularemia in 1951. There are a large number of insertion sequences including a mariner element, which is a transposon typically found in eukaryotes and is the first instance of this element to be found in a microbe, which may have acquired it during transit through one of the insect vectors. Causative agent of tularemia. This organism was first identified by Edward Francis as the causative agent of a plague-like illness that affected squirrels in Tulare county in California in the early part of the 20th century. The organism now bears his name. The disease, which has been noted throughout recorded history, can be transmitted to humans by infected ticks or deerflies, infected meat, or by aerosol, and thus is a potential bioterrorism agent. This organism has a high infectivity rate, and can invade phagocytic and nonphagocytic cells, multiplying rapidly. Once within a macrophage, the organism can escape the phagosome and live in the cytosol. It is an aquatic organism, and can be found living inside protozoans, similar to what is observed with Legionella.
Subject: NC_007384:4095016 Shigella sonnei Ss046, complete genome
Lineage: Shigella sonnei; Shigella; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: This strain is an isolate from an epidemic in China in the 1950s. A leading cause of 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. This 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. This organism is the leading cause of dysentery in industrialized countries. The disease is usually less severe than other types of Shigella, causing mild diarrhea and dehydration.