NC_009698:1985404 Clostridium botulinum A str. Hall chromosome, complete genome
Host Lineage: Clostridium botulinum; Clostridium; Clostridiaceae; Clostridiales; Firmicutes; Bacteria
General Information: Clostridium botulinum A strain Hall was received at Fort Detrick from Harvard University in 1947. The strain is presumably one from Dr. Ivan Hall's collection, but the exact strain number has been lost. This strain produces high amounts of type A toxin. Produces botulinum, one of the most potent toxins known. 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.