Query: NC_010673:479552 Borrelia hermsii DAH, complete genome
Lineage: Borrelia hermsii; Borrelia; Spirochaetaceae; Spirochaetales; Spirochaetes; Bacteria
General Information: This strain was isolated from a case of relapsing fever in western Washington, USA. Borrelia hermsii is the causative agent of tick-borne relapsing fever in the western United States and Canada. Borrelia then multiplies rapidly, causing a generalized infection throughout the tick. While feeding, the tick passes the organism into a mammalian host through its infectious saliva. Relapsing fever is characterized by a period of chills, fever, headache, and malaise, an asymptomatic period, followed by another episode of symptoms. This cycle of relapsing is due to changes in the surface proteins of Borrelia, which allow it to avoid detection and removal by the host immune system. This antigenic variation is the result of homologous recombination of silent proteins into an expressed locus, causing partial or complete replacement of one serotype with another. These plasmids carry genes involved in antigenic variation and pathogenicity.
Subject: NC_009749:1663500 Francisella tularensis subsp. holarctica FTA, complete genome
Lineage: Francisella tularensis; Francisella; Francisellaceae; Thiotrichales; Proteobacteria; Bacteria
General Information: Isolated from an immunocompetent 56-year old male with bacteremic pneumonia in France. Francisella tularensis is a non-motile, aerobic, rod-shaped Gram-negative bacterium and is the 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.