[L. Clostridium, a genus name, fr. Gr. klōstēr, spindle]
A genus of gram-positive, anaerobic, spore-forming bacilli in the family Bacillaceae. The genus comprises more than 250 species inhabit soil, water, and the intestinal tracts of humans and animals. Many species are pathogenic in humans, including those that colonize dead tissue, secrete numerous proteolytic enzymes, and cause gas gangrene.
SEE: gas gangrene

Clostridium baratii

A species in which some strains produce a neurotoxin that causes botulism.
SEE: botulism

Clostridium botulinum

The species that causes most cases of botulism. Under anaerobic conditions, C. botulinum produces a neurotoxin that causes paralysis by blocking the release of acetylcholine at neuromuscular junctions. The species comprises four distinct groups (labeled I through IV) initially grouped together by their ability to produce botulinum toxin (botulin).
SEE: botulism

Clostridium butyricum

A species in which some strains produce a neurotoxin that causes botulism.
SEE: botulism

Clostridium chauvoei

The species that causes blackleg or symptomatic anthrax in cattle.

Clostridium difficile

ABBR: C. diff. A species that causes watery diarrhea, fever, anorexia, and abdominal pain, sometimes accompanied by pseudomembranous colitis, esp. in patients previously treated with antibiotics or confined in health care settings. Most antibiotics (except aminoglycosides) have been associated with the development of C. diff.-associated disease, which varies in clinical significance from a relatively mild diarrheal illness, to one complicated by dehydration, electrolyte disturbances, toxic megacolon, and death. The disease is caused by two exotoxins released by the bacterium into the colon: TcdA and TcdB.

Infections with C. diff. may be detected with cytotoxin neutralization assays, enzyme immunoassays, polymerase chain reaction (PCR) assays, or loop-mediated isothermal amplification.

Outbreaks of C. diff. are found in many health care institutions, including nursing homes and hospitals. To prevent the spread of the disease in these facilities, staff should practice scrupulous hand hygiene, and patients affected by diarrheal illnesses should be isolated. Gowns and gloves should be worn by personnel attending infected patients. Linens should be disinfected and other infection control practices followed. Surfaces potentially contaminated by clostridial spores should be treated with hypochlorite bleaches (household bleach) as a disinfectant. Personal patient care items should not be shared or re-used. Mild to moderately infected patients typically improve with the oral administration of metronidazole or vancomycin; more severely ill patients may need infusions of vancomycin directly into the gastrointestinal tract. Patients with toxic megacolon may need surgery to remove damaged bowel. Fluid support intravenously and other elements of general supportive care also apply.

SEE: pseudomembranous colitis

Clostridium histolyticum

A species found in cases of gas gangrene.
SEE: gas gangrene

Clostridium novyi

A species found in many cases of gas gangrene.
SEE: gas gangrene

Clostridium perfringens

The species that is the most common cause of gas gangrene.
SYN: SEE: Clostridium welchii; SEE: gas bacillus
SEE: gas gangrene

Clostridium septicum

A species found in cases of gangrene in humans, cattle, hogs, and other domestic animals.
SEE: gangrene

Clostridium sordellii

A species that may cause anaerobic infections in bones, joints, soft tissues, the uterus, and elsewhere.

Clostridium sporogenes

A species frequently associated with other organisms in mixed gangrenous infections.
SEE: gangrene

Clostridium tetani

The species that causes tetanus.
SEE: tetanus

Clostridium welchii

SEE: Clostridium perfringens.