see also:

• clinically important bacteria

• Clostridium sp. are Gram positive sporing anaerobic bacteria which can cause a range of pathologies
• spores are generally extremely durable and can survive in the environment for very long periods, often in the order of years to decades under suitable conditions
  • in soil, meats, and food environments, spores commonly persist for months to many months, with some data showing little loss of viability after 6 months at refrigeration (4°C) or freezing (−20°C)
  • some species spores such as perfringens are highly resistant to heat, drying, pH extremes, and many disinfectants; they can survive boiling‑equivalent treatments for up to an hour or more in some strains - reliable inactivation generally requires moist‑heat sterilisation (e.g., 121°C for ≥15 minutes), as routine cooking kills vegetative cells but often leaves spores intact hence they are a major concern in food‑safety and infection‑control settings

• a normal inhabitant of the human and animal gut, and the environment
• it is a “multi‑toxin pleiotropic” pathogen with necrotising and diarrhoeal phenotypes
• can produce multiple toxins, including alpha, beta, epsilon, iota, and enterotoxin (CPE), with up to about 12–16 different toxins described
  • alpha toxin (phospholipase C) is the major virulence factor for gas gangrene, causing myonecrosis, haemolysis, and vascular leak via membrane phospholipid hydrolysis
  • enterotoxin (CPE) causes diarrhoeal food poisoning by disrupting intestinal tight junctions and triggering apoptosis of gut epithelial cells
  • other toxins (beta, epsilon, iota) drive severe necrotising enteritis and enterotoxaemia in animals (and occasionally humans), via membrane disruption or actin‑cytoskeleton destruction
• can cause:
  • food poisoning
    • Clostridium perfringens spores on raw or inadequately cooked meat survive normal cooking; they germinate when the meat is held in the “danger zone” (roughly 12–60°C) for several hours, a warm, nutrient‑rich, anaerobic environment where C. perfringens grows very rapidly (generation times can be <20 minutes) - germination and growth convert heat‑resistant spores into metabolically active vegetative cells that multiply to high numbers (often >10⁶ CFU/g) in the meat before it is eaten - when a person ingests meat containing large numbers of vegetative C. perfringens cells, these cells reach the small intestine, sense nutrient limitation, and initiate sporulation; this triggers production of C. perfringens enterotoxin (CPE), which forms pores in intestinal epithelial cells and causes watery diarrhoea and cramps 8–24 hours after ingestion.
  • enterotoxaemia
  • gas gangrene / Clostridial myonecrosis
  • Fournier's gangrene
  • necrotizing fasciitis

• an obligate‑anaerobic, spore‑forming, Gram‑positive bacillus commonly found in soil, dust, and animal/human faeces.
• its spores are highly resistant and can survive for years in the environment
• when spores enter a devitalised, low‑oxygen wound they germinate into vegetative bacilli that produce tetanospasmin, a potent neurotoxin responsible for the muscle rigidity and spasms of tetanus

• see Clostridium difficile

• C. butyricum
• C. baratii
• C. sporogenes
• see botulism