Query: NC_016516:1345840 Propionibacterium acnes TypeIA2 P.acn33 chromosome, complete
Lineage: Propionibacterium acnes; Propionibacterium; Propionibacteriaceae; Actinomycetales; Actinobacteria; Bacteria
General Information: This bacterium is the most common gram-positive, non-spore forming, anaerobic rod encountered in clinical specimens. The causative agent of acne, it typically grows as an obligate anaerobe. Some strains are aerotolerant, but still show better growth as an anaerobe. It has the ability to produce propionic acid, as its name suggests. It also has the ability to produce catalase along with indole, nitrate, or both indole and nitrate. Propionibacterium resembles Corynebacterium in morphology and arrangement, but is non-toxigenic. It is a common resident of the pilosebaceous (hair follicle) glands of the human skin. The bacteria release lipases to digest a surplus of the skin oil, sebum, that has been produced. The combination of digestive products (fatty acids) and bacterial antigens stimulates an intense local inflammation that bursts the hair follicle. Since acne is caused in part from an infection, it can be suppressed with topical and oral antibiotics such as clindamycin, erythromycin, or tetracycline. Some other forms of therapy include chemicals that enhance skin removal or slow the production of sebum.
Subject: NC_008261:576923 Clostridium perfringens ATCC 13124, complete genome
Lineage: Clostridium perfringens; Clostridium; Clostridiaceae; Clostridiales; Firmicutes; Bacteria
General Information: The species type strain, originally isolated from a human gas gangrene patient. Causative agent of gas gangrene. 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 is a causative agent of a wide spectrum of necrotic enterotoxicoses. It also causes such animal diseases as lamb dysentery, ovine enterotoxemia (struck), pulpy kidney disease in lambs and other enterotoxemias in lambs and calves. It is commonly found in the environment (soil, sewage) and in the animal and human gastrointestinal tract as a member of the normal microflora. It is a fast growing (generation time 8-10 min) anaerobic flesh-eater. Active fermentative growth is accompanied by profuse generation of molecular hydrogen and carbon dioxide. It is also oxygen tolerant which makes it an easy object to work with in laboratories. C. perfringens have been developed and the species became a model organism in clostridial genetic studies. Known isolates belong to five distinct types (A, B, C, D, and E) that are distinguished based on the specific extracellular toxins they produce. Known isolates belong to five distinct types (A, B, C, D, and E) that are distinguished based on the specific extracellular toxins they produce. All types produce the alpha toxin (phospholipase C). Type A strains that cause gas gangrene produce alpha toxin, theta (hemolysin), kappa (collagenase), mu (hyaluronidase), nu (DNAse) and neuraminidase which are all the enzymatic factors aiding the bacterium in invading and destruction of the host tissues. Type C strains produce alpha toxin, beta toxin and prefringolysin enteritis. In addition to alpha toxin, Type B strains produce beta toxin, types B and D produce the pore forming epsilon toxin and type E strains produce iota toxin.