| Clostridium perfringens | |
|---|---|
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| Photomicrograph of gram-positive Clostridium perfringens bacilli. | |
| Scientific classification | |
| Kingdom: | Bacteria |
| Phylum: | Firmicutes |
| Class: | Clostridia |
| Order: | Clostridiales |
| Family: | Clostridiaceae |
| Genus: | Clostridium |
| Species: | C. perfringens |
| Binomial name | |
| Clostridium perfringens Veillon & Zuber 1898 Hauduroy et al. 1937 |
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Clostridium perfringens (formerly known as C. welchii) is a Gram-positive, rod-shaped, anaerobic, spore-forming bacterium of the genus Clostridium.[1] C. perfringens is ever present in nature and can be found as a normal component of decaying vegetation, marine sediment, the intestinal tract of humans and other vertebrates, insects, and soil.
C. perfringens is the third most common cause of food poisoning in the United Kingdom and the United States[2] though it can sometimes be ingested and cause no harm.[3]
Infections due to C. perfringens show evidence of tissue necrosis, bacteremia, emphysematous cholecystitis, and gas gangrene, which is also known as clostridial myonecrosis. The toxin involved in gas gangrene is known as α-toxin, which inserts into the plasma membrane of cells, producing gaps in the membrane that disrupt normal cellular function.[2] C. perfringens can participate in polymicrobial anaerobic infections.[4] Clostridium perfringens is commonly encountered in infections as a component of the normal flora.[5] In this case, its role in disease is minor.
The action of C. perfringens on dead bodies is known to mortuary workers as tissue gas and can be halted only by embalming.
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Food poisoning[edit]
In the United Kingdom and United States, C. perfringens bacteria are the third most common cause of foodborne illness, with poorly prepared meat and poultry, or food properly prepared but left to stand too long, the main culprits in harboring the bacterium.[2] The clostridium perfringens enterotoxin (CPE) mediating the disease is heat-labile (inactivated at 74 °C (165 °F)) and can be detected in contaminated food, if not heated properly, and feces.[6] Incubation time is between six and 24 (commonly 10-12) hours after ingestion of contaminated food.
Since C. perfringens forms spores that can withstand cooking temperatures, if cooked food is let stand for long enough, germination can ensue and infective bacterial colonies develop. Symptoms typically include abdominal cramping, diarrhea; vomiting and fever are usual. The whole course usually resolves within 24 hours. Very rare, fatal cases of clostridial necrotizing enteritis (also known as pigbel) have been known to involve "Type C" strains of the organism, which produce a potently ulcerative β-toxin. This strain is most frequently encountered in Papua New Guinea.
Many cases of C. perfringens food poisoning likely remain subclinical, as antibodies to the toxin are common among the population. This has led to the conclusion that most of the population has experienced food poisoning due to C. perfringens.[2]
Despite its potential dangers, C. perfringens is used as the leavening agent in salt rising bread. The baking process is thought to reduce the bacterial contamination, precluding negative effects.[3]
Infection[edit]
Clostridium perfringens is the most common bacterial agent for gas gangrene, which is necrosis, putrefaction of tissues, and gas production. It is caused primarily by Clostridium perfringens alpha toxin. The gases form bubbles in muscle (crepitus) and the characteristic smell in decomposing tissue. After rapid and destructive local spread (which can take only hours), systemic spread of bacteria and bacterial toxins may cause death. This is a problem in major trauma and in military contexts. C. perfringens grows readily on blood agar plate in anaerobic conditions, and often produces a double zone of beta hemolysis.
Diagnosis[edit]
C. perfringens can be diagnosed by Nagler's Reaction where the suspect organism is cultured on an egg yolk media plate. One side of the plate contains anti-alpha-toxin, while the other side does not. A streak of suspect organism is placed through both sides. An area of turbidity will form around the side that does not have the anti-alpha-toxin, indicating uninhibited lecithinase activity.
Treatment[edit]
If detected on clinical ground, treatment should begin without waiting for lab results. Traumatic wounds should be cleaned. Wounds that cannot be cleaned should not be stitched shut. Penicillin prophylaxis kills many clostridia, and is thus useful for dirty wounds and lower leg amputations. A high infectious dose is required; the carrier state persists for several days.
Food poisoning incidents[edit]
In May 2011, a man died after allegedly eating food contaminated with the bacteria on a transatlantic American Airlines flight. The man's wife and daughter are suing American and LSG Sky Chefs, the German company that prepared the inflight food.[7]
In December 2012, a 46-year-old woman died two days after eating a Christmas Day meal at a pub in Hornchurch, Essex, England. She was among about 30 people to fall ill after eating the meal. Samples taken from the victims contained C.perfringens. The woman's husband said that he intended to take legal action over his wife's death. [8]
References[edit]
- ^ Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. ISBN 0-8385-8529-9.[page needed]
- ^ a b c d Warrell et al. (2003). Oxford Textbook of Medicine (4th ed.). Oxford University Press. ISBN 0-19-262922-0.[page needed]
- ^ a b Juckett, G; Bardwell, G; McClane, B; Brown, S (2008). "Microbiology of salt rising bread". The West Virginia medical journal 104 (4): 26–7. PMID 18646681.
- ^ Brook, I (2007). "The role of anaerobic bacteria in cutaneous and soft tissue abscesses and infected cysts". Anaerobe 13 (5–6): 171–7. doi:10.1016/j.anaerobe.2007.08.004. PMID 17923425.
- ^ Wells CL, Wilkins TD (1996). Clostridia: Sporeforming Anaerobic Bacilli. In: Barron's Medical Microbiology (Barron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. ISBN 0-9631172-1-1. (via NCBI Bookshelf).[page needed]
- ^ Murray et al. (2009). Medical Microbiology (6th ed.). Mosby Elsevier. ISBN 978-0-323-05470-6.[page needed]
- ^ Mohn, Tanya. "Overhead Bin - Passenger dies in-flight, family says airline to blame". Overheadbin.msnbc.msn.com. Retrieved 2012-02-13.
- ^ "Husband's anger at hospital and pub after his wife dies from suspected Christmas Day food poisoning". Daily Mail. 4 January 2012.
External links[edit]
- Clostridium perfringens genomes and related information at PATRIC, a Bioinformatics Resource Center funded by NIAID
- Pathema-Clostridium Resource
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