Query: NC_012225:1657248 Brachyspira hyodysenteriae WA1, complete genome
Lineage: Brachyspira hyodysenteriae; Brachyspira; Brachyspiraceae; Spirochaetales; Spirochaetes; Bacteria
General Information: Brachyspira hyodysenteriae is the causative agent of swine dysentery, which is a severe mucohemorrhagic diarrheal disease of pigs that has economic significance for pork-producing countries. The bacterium can survive for several weeks in cold moist conditions but not under warm dry conditions. It spreads slowly, building up in numbers as the dose rate of the causal agent builds up in the environment. Pigs that recover develop a low immunity and rarely suffer from the disease again. It can be spread by other organisms (flies, mice, birds and dogs) or external mechanical factors; its main habitat is the porcine cecum and colon. It is chemotactically attracted to mucin which it penetrates with a corkscrew-like motility.
Subject: NC_004557:2078000 Clostridium tetani E88, complete genome
Lineage: Clostridium tetani; Clostridium; Clostridiaceae; Clostridiales; Firmicutes; Bacteria
General Information: This strain is a virulent nonsporulating variant of strain Massachusetts used in vaccine production. Causes tetanus. 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. Known opportunistic toxin-producing pathogens in animals and humans. Some species are capable of producing organic solvents (acetone, ethanol, etc,), molecular hydrogen and other useful compounds. This organism causes tetanus (lockjaw) in humans. At the tissue level, the bacterium then releases an exotoxin called tetanospasmin that causes certain nervous system irregularities by means of retrograde tramsmission through neurons to the brain. If nervous impulses cannot be checked by normal inhibitory mechanisms, it produces the generalized muscular spasms characteristic of tetanus.