(klos-trid'ē-ŭm )

[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.

C. baratii A species in which some strains produce a neurotoxin that causes botulism.

SEE: botulism.

C. 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.

C. butyricum A species in which some strains produce a neurotoxin that causes botulism.

SEE: botulism.

C. chauvoei The species that causes blackleg or symptomatic anthrax in cattle.

C. histolyticum A species found in cases of gas gangrene.

SEE: gas gangrene.

C. novyi A species found in many cases of gas gangrene.

SEE: gas gangrene.

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

SEE: gas gangrene.

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

SEE: gangrene.

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

C. sporogenes A species frequently associated with other organisms in mixed gangrenous infections.

SEE: gangrene.

C. tetani The species that causes tetanus.

SEE: tetanus.

C. welchii Clostridium perfringens.

SEE: Clostridioides.