Clostridium

A group of anaerobic bacteria (bacteria that thrive in the absence of oxygen). There are 100+ species of Clostridium. They include, for examples, Clostridium difficile, Clostridium perfringens (also called Clostridium welchii), and Clostridium botulinum. Clostridium difficile is one of the most common causes of infection of the large bowel (the colon) in the US affecting millions of people yearly. Patients taking antibiotics are at risk of becoming infected with C. difficile. Antibiotics disrupt the normal bacteria of the bowel, allowing C. difficile bacteria to become established in the colon. Many persons infected with C.difficile have no symptoms. These people become carriers of the bacteria and can infect others. In other people, a toxin produced by C. difficile causes diarrhea, abdominal pain, severe inflammation of the colon (colitis), fever, an elevated white blood count, vomiting and dehydration. In severely affected patients, the inner lining of the colon becomes severely inflamed (a condition called pseudomembranous colitis). Rarely, the walls of the colon wear away and holes develop (colon perforation), which can lead to a life-threatening infection of the abdomen. Clostridium perfrigens, also known as Clostridium welchii), this is the most common agent of gas gangrene and also causes food poisoning as well as a fulminant form of bowel disease called necrotizing colitis. Clostridium botulinum is the culprit responsible for the food poisoning and other problems associated with botulism.

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A genus of anaerobic (or anaerobic, aerotolerant), spore-forming, motile (occasionally nonmotile) bacteria (family Bacillaceae) containing Gram-positive rods; motile cells are peritrichous. Many of the species are saccharolytic and fermentative, producing various acids and gases and variable amounts of neutral products; other species are proteolytic, some attacking proteins with putrefaction or more complete proteolysis. Some species fix free nitrogen. These organisms sometimes produce exotoxins; they are generally found in soil and in the mammalian intestinal tract, where they may cause disease. The type species is C. butyricum. [G. kloster, a spindle]

- C. bifermentans a bacterial species found in putrid meat and gaseous gangrene; also commonly found in soil, feces, and sewage. Its pathogenicity (largely due to an edema-producing toxin) varies from strain to strain.

- C. botulinum a bacterial species that occurs widely in nature and is a frequent cause of food poisoning (botulism) from preserved meats, fruits, or vegetables that have not been properly sterilized before canning. The main types, A to F, are characterized by antigenically distinct, but pharmacologically similar, very potent neurotoxins, each of which can be neutralized only by the specific antitoxin; group C toxin contains at least two components; the recorded cases of human botulism have been due mainly to types A, B, E, and F; infant botulism occurs when colonization of the gastrointestinal tract with C. botulinum results in absorption of the toxin through the gastrointestinal wall; type Cα causes botulism in domestic and wild water fowl; Cβ and D are associated with intoxications in cattle. Type E is usually associated with improperly processed fish products.

- C. butyricum a bacterial species that occurs in naturally soured milk, in naturally fermented starchy plant substances, and in soil; formerly considered nonpathogenic, it is now known to include neurotoxin-producing strains; the type species of the genus C..

- C. cadaveris a bacterial species found in a human feces and in the pleural fluid of a sheep; it is not pathogenic for guinea pig s or rabbits, but has been a rare cause of gas gangrene in humans.

- C. carnis a bacterial species found in a rabbit inoculated with soil; it is pathogenic for laboratory animals, in which an exotoxin produces edema, necrosis, and death.

- C. chauvoei a bacterial species that causes blackleg, black quarter, or symptomatic anthrax in cattle and other animals and that produces an exotoxin.

- C. cochlearium a bacterial species found in human war wounds and septic infections; it is not pathogenic for guinea pig s.

- C. difficile (di-fi′-sel) a bacterial species found in feces of humans and animals. It colonizes newborn infants, who are spared from toxin induced diarrheal disease. Pathogenic for human beings, guinea pig s, and rabbits; frequent cause of colitis and diarrhea following antibiotic use. Found to be a cause of pseudomembranous colitis and associated with a number of intestinal diseases that are linked to antibiotic therapy; also the chief cause of nosocomial diarrhea. [L. difficult]

- C. fallax a bacterial species found in war wounds, appendicitis, and black leg of sheep; it produces a weak exotoxin.

- C. haemolyticum a bacterial species found in cattle dying of icterohemoglobinuria; it is pathogenic and toxic for guinea pig s and rabbits and produces an unstable, hemolytic toxin.

- C. histolyticum a bacterial species found in war wounds, where it induces necrosis of tissue; it produces cytolytic exotoxins that cause local necrosis and sloughing on injection; it is not toxic on feeding; it is pathogenic for small laboratory animals.

- C. innominatum a bacterial species found in septic and gangrenous war wounds.

- C. nigrificans former name for Desulfotomaculum nigrificans.

- C. novyi a bacterial species consisting of three types, A, B, and C; type A, from a case of gaseous gangrene and from human necrotic hepatitis, produces γ-toxin (a hemolytic lecithinase); B, from black disease (infectious necrotic hepatitis) of sheep, produces β-toxin (a hemolytic lecithinase); and C, found in bacillary osteomyelitis of water buffaloes, does not produce toxin. SYN: C. oedematiens.

- C. oedematiens SYN: C. novyi.

- C. parabotulinum a bacterial species containing formerly referred to as C. botulinum types A and B; the types are identified by protection tests with known type antitoxin; it produces a powerful exotoxin and is pathogenic for humans and other animals.

- C. paraputrificum a bacterial species found in feces (especially of infants), gaseous gangrene, and postmortem fluid and tissue cultures; it is not pathogenic for rabbits or guinea pig s.

- C. perfringens a bacterial species that is the chief causative agent of gas gangrene in humans and a cause of gas gangrene in other animals, especially sheep; it may also be involved in causing enteritis, appendicitis, and puerperal fever; it is one of the most common causes of food poisoning in the U. S. This organism is found in soil, water, milk, dust, sewage, and the intestinal tract of humans and other animals. SYN: C. welchii, gas bacillus, Welch bacillus.

- C. ramosum a bacterial species found in the natural cavities of humans and other animals as well as in seawater and in feces; it is also found in association with mastoiditis, otitis, pulmonary gangrene, putrid pleurisy, appendicitis, intestinal infections, balanitis, liver abscess, osteomyelitis, septicemia, and urinary infections. It was formerly the type species of the obsolete genus Ramibacterium.

- C. septicum a bacterial species found in malignant edema of animals, in human war wounds, and in cases of appendicitis; it is pathogenic for guinea pig s, rabbits, mice, and pigeons and produces an exotoxin that is lethal and hemolytic. SYN: Vibrion septique.

- C. sordellii a bacterial strain that produces multiple toxins including a lecithinase, hemolysin, and a fibrinolysin, which result in edema and potentially fatal hypotension, and necrotic infections in humans. It is especially associated with abdominal and gynecologic posttraumatic and postoperative wound infection; also causes big head in rams.

- C. sphenoides a bacterial species found in gangrenous war wounds; it is not pathogenic for guinea pig s or rabbits.

- C. sporogenes a bacterial species found in intestinal contents, gaseous gangrene, and soil; it is not pathogenic for guinea pig s or rabbits, but does produce a slight, temporary, local tumefaction.

- C. tertium a bacterial species found in wounds, but that is nonpathogenic for laboratory animals.

- C. tetani the bacterial species that causes tetanus; it produces a potent exotoxin (neurotoxin) that is intensely toxic for humans and other animals when formed in tissues or injected, but not when ingested.

- C. thermosaccharolyticum a bacterial species of thermophilic bacteria found in “hard swell” of canned goods; it is not pathogenic to laboratory animals.

- C. welchii SYN: C. perfringens.

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clos·trid·i·um kläs-'trid-ē-əm n

1) cap a genus of saprophytic rod-shaped or spindle-shaped usu. gram-positive bacteria of the family Bacillaceae that are anaerobic or require very little free oxygen and are nearly cosmopolitan in soil, water, sewage, and animal and human intestines, that are very active biochemically comprising numerous fermenters of carbohydrates with vigorous production of acid and gas, many nitrogen-fixers, and others which rapidly putrefy proteins, and that include important pathogens see BLACKLEG, BOTULISM, GAS GANGRENE, TETANUS BACILLUS

2) pl clos·trid·ia -ē-ə

a) any bacterium of the genus Clostridium

b) a spindle-shaped or ovoid bacterial cell esp one swollen at the center by an endospore

clos·trid·i·al -ē-əl adj

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n.

a genus of mostly Gram-positive anaerobic spore-forming rodlike bacteria commonly found in soil and in the intestinal tract of humans and animals. Many species cause disease and produce extremely potent exotoxin. C. botulinum grows freely in badly preserved canned foods, producing a toxin causing serious food poisoning (botulism); an extremely dilute form of this toxin is now used to treat muscle spasm (see botulinum toxin). C. histolyticum, C. oedematiens, and C. septicum all cause gas gangrene when they infect wounds. C. tetani lives as a harmless commensal in the intestine but causes tetanus on contamination of wounds (with manured soil). The species C. perfringens - Welch's bacillus - causes blood poisoning, food poisoning, and gas gangrene. Overgrowth of C. difficile, a normal inhabitant of the human large intestine, is not uncommon as a complication of some antibiotic therapy and produces a specific condition - pseudomembranous colitis - which is life-threatening unless treated promptly.

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Clos·trid·i·um (klos-tridґe-əm) [Gr. klōstēr spindle] a genus of bacteria of the family Clostridiaceae, consisting of obligate anaerobic or microaerophilic, gram-positive, spore-forming, rod-shaped bacilli, with spores of greater diameter than the vegetative cells. The spores may be central, terminal, or subterminal. Nearly two hundred species have been differentiated on the basis of physiology, morphology, and toxin formation; pathogenic species produce destructive exotoxins or enzymes. Different species are found in soil, in water, and in the intestinal tracts of animals.