Pre_GI: SWBIT SVG BLASTP

Query: NC_012581:559182 Bacillus anthracis str. CDC 684 chromosome, complete genome

Lineage: Bacillus anthracis; Bacillus; Bacillaceae; Bacillales; Firmicutes; Bacteria

General Information: This organism was the first to be shown to cause disease by Dr. Robert Koch, leading to the formulation of Koch's postulates, which were verified by Dr. Louis Pasteur (the organism, isolated from sick animals, was grown in the laboratory and then used to infect healthy animals and make them sick). This organism was also the first for which an attenuated strain was developed as a vaccine. Herbivorous animals become infected with the organism when they ingest spores from the soil whereas humans become infected when they come into contact with a contaminated animal. Anthrax is not transmitted due to person-to-person contact. The three forms of the disease reflect the sites of infection which include cutaneous (skin), pulmonary (lung), and intestinal. Pulmonary and intestinal infections are often fatal if left untreated. Spores are taken up by macrophages and become internalized into phagolysozomes (membranous compartment) whereupon germination initiates. Bacteria are released into the bloodstream once the infected macrophage lyses whereupon they rapidly multiply, spreading throughout the circulatory and lymphatic systems, a process that results in septic shock, respiratory distress and organ failure. The spores of this pathogen have been used as a terror weapon.

Subject: NC_006142:57571 Rickettsia typhi str. Wilmington, complete genome

Lineage: Rickettsia typhi; Rickettsia; Rickettsiaceae; Rickettsiales; Proteobacteria; Bacteria

General Information: This genus, like other Rickettsial organisms such as Neorickettsia and Anaplasma, is composed of obligate intracellular pathogens. The latter is composed of two organisms, Rickettsia prowazekii and Rickettsia typhi. The bacteria are transmitted via an insect, usually a tick, to a host organism, in this case humans, 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. Transovarial transmission (from mother to offspring) occurs in the invertebrate host. Rickettsia typhi causes murine typhus and is an obligate intracellular pathogen that infects both the flea vector and hosts such as human, rat, and mouse. In the flea vector, the bacterium penetrates the gut epithelial barrier and is found in the feces which become infective.