Query: NC_016933:1481000 Francisella tularensis TIGB03 chromosome, complete genome
Lineage: Francisella tularensis; Francisella; Francisellaceae; Thiotrichales; Proteobacteria; Bacteria
General Information: 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_010723:1133163 Clostridium botulinum E3 str. Alaska E43, complete genome
Lineage: Clostridium botulinum; Clostridium; Clostridiaceae; Clostridiales; Firmicutes; Bacteria
General Information: This strain was probably isolated from salmon eggs associated with a foodborne case of botulism in Alaska, however the exact details are not available. This genus comprises about 150 metabolically diverse species of anaerobes that are ubiquitous in virtually all anoxic habitats where organic compounds are present, including soils, aquatic sediments and the intestinal tracts of animals and humans. This shape is attributed to the presence of endospores that develop under conditions unfavorable for vegetative growth and distend single cells terminally or sub-terminally. Spores germinate under conditions favorable for vegetative growth, such as anaerobiosis and presence of organic substrates. It is believed that present day Mollicutes (Eubacteria) have evolved regressively (i.e., by genome reduction) from gram-positive clostridia-like ancestors with a low GC content in DNA. This organism produces one of the most potent and deadly neurotoxins known, a botulinum toxin that prevents the release of acetylcholine at the neuromuscular junction, thereby inhibiting muscle contraction and causing paralysis. In most cases the diseased person dies of asphyxiation as a result of paralysis of chest muscles involved in breathing. The spores are heat-resistant and can survive in inadequately heated, prepared, or processed foods. Spores germinate under favorable conditions (anaerobiosis and substrate-rich environment) and bacteria start propagating very rapidly, producing the toxin.Botulinum toxin, and C. botulinum cells, has been found in a wide variety of foods, including canned ones. Almost any food that has a high pH (above 4.6) can support growth of the bacterium. Honey is the most common vehicle for infection in infants. Food poisoning through C. botulinum is the most frequent type of infection caused by this bacterium. The wound botulism that occurs when C. botulinum infects an individual via an open wound is much rarer and is very similar to tetanus disease. There are several types of botulinum toxin known (type A through type F), all of them being neurotoxic polypeptides. The most common and widely distributed are strains and serovars of C. botulinum that produce type A toxin.