PatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
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.
Can be caused by various clostridia - eg, Clostridium perfringens, Clostridium septicum, Clostridium novyi and Clostridium histolyticum. See separate Gas Gangrene article.
Caused by Clostridium tetani. See separate Tetanus article.
Caused by Clostridium difficile. See separate Pseudomembranous Colitis article.
Caused by a neurotoxin of Clostridium botulinum. See separate Botulism article.
Botulism and bioterrorism
- The most toxic substance known to man; a lethal dose <1 microgram.
- 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
This is the fourth most common 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. They produce exotoxin, requiring a large infective dose.
- It is 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.
- Clinically it appears similar to gas gangrene, now rare in UK with the legalisation of abortions.
- Formerly the leading cause of maternal death worldwide, it is still a problem in developing countries, due to illegal abortions and poor obstetric practice.
- Two major factors are involved:
- Infection, which is commonly caused by C. perfringens in mixed infection with non-sporing anaerobes (eg, Bacteroides spp.), Group B beta-haemolytic streptococci, staphylococci, or Escherichia coli, Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma spp.
- Retained products of conception.
Further reading & references
- Clostridium difficile infection: how to deal with the problem, Guidance from the Dept of Health, January 2009
- Chan-Tack KM et al; Botulism, Medscape, May 2011
- Curry JA; Pseudomembranous Colitis, Medscape, Sep 2011
- Tetanus; Public Health England
- Botulism deliberate release guidelines, Health Protection Agency
- Clostridium difficile, Health Protection Agency
- Clostridium perfringens, Health Protection Agency
- Osborne SL, Latham CF, Wen PJ, et al; The Janus faces of botulinum neurotoxin: Sensational medicine and deadly biological weapon. J Neurosci Res. 2007 May 1;85(6):1149-58.
- de Jong AE, Rombouts FM, Beumer RR; Behavior of Clostridium perfringens at low temperatures. Int J Food Microbiol. 2004 Dec 1;97(1):71-80.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Hayley Willacy
Dr Colin Tidy
Dr Adrian Bonsall