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Tetanus
Pseudomembranous Colitis
Gas Gangrene
Botulism

Clostridia are anaerobic, Gram-positive, spore-forming rods widely distributed in nature, particularly in soil. They form resistant spores under stress. These spores, which can survive brief heating to 100 °C, and the powerful exotoxins the active bacteria produce are central to the medical importance of the species.

Gas gangrene

Can be caused by various clostridia, e.g. Clostridium perfringens, Clostridium septicum, Clostridium novyi and Clostridium histolyticum. To see Gas Gangrene record, click here.

Septic abortion

• Clinically it appears similar to gas gangrene, now rare in UK with the legalisation of abortions.
• Formerly the leading cause of maternal death worldwide, still a problem in developing countries, due to illegal abortions and poor obstetric practice.^1,2,3
• 2 major factors are involved:
  • Infection, which is commonly caused by Clostridium perfringens in mixed infection with non-sporing anaerobes (e.g. Bacteroides spp.), Group B beta-haemolytic streptococci, staphylococci, or Escherichia coli, Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma spp.
  • Retained products of conception

Tetanus

Caused by Clostridium tetani. See Tetanus record.

Pseudomembranous colitis

Caused by Clostridium difficile. See Pseudomembranous Colitis record.

Botulism

Caused by neurotoxin of Clostridium botulinum. See Botulism record.

Botulism and bioterrorism

• The most toxic substance known to man⁴; a lethal dose <1 mcg.
• The Germans were developing the toxin in WWII as a cross-channel weapon, and the death of the head of the Gestapo in 1942 was attributed to a hand grenade contaminated with toxin, supplied to the Czech patriots by the British.
• A deliberate release may involve airborne dissemination of toxin, or contamination of food or water supplies with toxin or bacteria.
• Water treatment inactivates the toxin, the toxin cannot penetrate intact skin and it loses activity within a few days.
• The most likely scenarios would therefore be:
  • A deliberate contamination of foodstuffs; large doses may lead directly to neurological symptoms without the gastrointestinal symptoms of nausea, vomiting, and diarrhoea followed by constipation.
  • Aerosol release; most effective in an enclosed environment. After inhalation, the onset of symptoms may be as rapid as <1 hour. However, in cases of accidental inhalation symptom onset can be 3-4 days.

Clostridium perfringens food poisoning

Fourth commonest form of food-borne illness, after Norwalk-like viruses, Campylobacter spp; and Salmonella spp.

• Spores survive cooking, and germinate during slow cooling or unrefrigerated storage.⁵ They produce exotoxin, requiring a large infective dose.
• Mostly associated with meat and poultry, usually occurring in schools, hospitals, factories and catering establishments.Typically, a meat dish is stewed or boiled and allowed to stand for 4-24 hours and then served without adequate reheating.
• 6-12 hours later the patient suffers crampy abdominal pain followed by diarrhoea, which subsides 12-24 hours later.