Theta toxin (Θ-toxin)Theta toxin is also employed by Clostridium perfingens as a virulence factor. Theta toxin also promotes vascular degradation as its counterpart alpha toxin. A platelet-activation factor is employed which triggers an acute inflammatory response in nearby tissues. This inflammatory response leads to constriction of surrounding arteries and promotes an anaerobic environment for Clostridium perfingens growth and pathophysiology. Beta toxin (β-toxin)Beta toxin is an integral virulence factor in promoting enterocolitics and enterotoxemia. This toxin uses pores in the cellular biolipid membrane to import a pathogenic factor into organisms. Pathophysiology
Gas gangrene is caused by exotoxin-producing Clostridium species (most often C. perfringens, and C. novyi, but less commonly C. septicum or C. ramnosum), which are mostly found in soil, but also found as normal gut flora, and other anaerobes (e.g., Bacteroides and anaerobic streptococci).Bacterium of the Clostridial species produce two toxins: alpha and theta toxins, which cause necrotizing damage to tissues.Other organisms may occasionally cause gas gangrene (for example, Klebsiella pneumoniae in the context of diabetes).A gas composition of 5.9% hydrogen, 3.4% carbon dioxide, 74.5% nitrogen, and 16.1% oxygen was reported in one clinical case.Myonecrosis differs slightly from other types of necrosis. While the underlying causes are almost identical, the type of affected tissue (in particular, muscle tissue) is significantly more important for the patients general health. Superficial necrosis is unsightly and can lead to unattractive scarring, but otherwise does not affect the patients likelihood of survival or physical capability to the same extent.
Gas gangrene (also known as clostridial myonecrosis and myonecrosis) is a bacterial infection that produces tissue gas in gangrene. This deadly form of gangrene usually is caused by Clostridium perfringens bacteria. About 1,000 cases of gas gangrene are reported yearly in the United States.Myonecrosis is a condition of necrotic damage, specific to muscle tissue. It is often seen in infections with C. perfringens or any of myriad soil-borne anaerobic bacteria. Bacteria cause myonecrosis by specific exotoxins. These microorganisms are opportunistic and, in general, enter the body through significant skin breakage. Gangrenous infection by soil-borne bacteria was common in the combat injuries of soldiers well into the 20th century, because of non-sterile field surgery and the basic nature of care for severe projectile wounds.Other causes of myonecrosis include envenomation by snakes of the genus Bothrops (family Viperidae), ischemic necrosis, caused by vascular blockage (e.g., diabetes type II), tumours that block or hoard blood supply, and disseminated intravascular coagulation or other thromboses. Presentation
Gas gangrene can cause myonecrosis (muscle tissue death), gas production, and sepsis. Progression to toxemia and shock is often very rapid. It can easily be noticed by the large, blackened sores that form, as well as a degree of loud and distinctive crepitus caused by gas escaping the necrotic tissue. Symptoms
A multitude of symptoms is associated with Gas gangrene. Distinctively, black lesions on the skin appear in a bubble form which allows visualization of gas-producing bacteria.