Clostridium perfringens
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{{Taxobox
| color = lightgrey
| name = ''Clostridium perfringens''
| image = Clostridium_perfringens.jpg
| image_width = 240px
| image_caption = Photomicrograph of gram-positive ''Clostridium prumpfringens'' bacilli.
| regnum = [[Bacterium|Bacteria]]
| divisio = [[Firmicutes]]
| classis = [[Clostridia]]
| ordo = [[Clostridia]]les
| familia = [[Clostridiaceae]]
| genus = ''[[Clostridium]]''
| species = ''''' perfringens'''''
| binomial = ''Clostridium perfringens''
| binomial_authority = Veillon & Zuber 1898<br>Hauduroy ''et al.'' 1937
}}
'''''Clostridium perfringens''''' (formerly known as ''Clostridium welchii'') is a [[Gram-positive]], rod-shaped, [[anaerobic bacterium|anaerobic]], [[Endospore|spore-forming]] [[bacterium]] of the genus ''[[Clostridium]]''.<ref name=Sherris>{{cite book | author = Ryan KJ; Ray CG (editors) | title = Sherris Medical Microbiology | edition = 4th ed. | publisher = McGraw Hill | year = 2004|id = ISBN 0-8385-8529-9 }}</ref> ''C. perfringens'' is ubiquitous in nature and can be found as a normal component of decaying vegetation, marine sediment, the [[Intestine|intestinal tract]] of [[human]]s and other [[vertebrate]]s, [[insect]]s, and [[soil]]. Virtually every soil sample ever examined, with the exception of the [[sand]]s of the [[Sahara]], has contained ''C. perfringens''.{{Fact|date=May 2008}}
==Infection characteristics==
''C. perfringens'' is commonly encountered in [[infection]]s as a benign component of the normal [[flora (microbiology)|flora]].<ref name=Barron>{{cite book | author = Wells CL, Wilkins TD | title = Clostridia: Sporeforming Anaerobic Bacilli. ''In:'' Barron's Medical Microbiology ''(Barron S ''et al'', eds.)| edition = 4th ed. | publisher = Univ of Texas Medical Branch | year = 1996|id = [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mmed.section.1131 (via NCBI Bookshelf)] ISBN 0-9631172-1-1 }}</ref> In this case, its role in disease is minor. Infections due to ''C. perfringens'' show evidence of tissue [[necrosis]], [[bacteremia]], [[emphysema]]tous [[cholecystitis]], and [[gas gangrene]], which is also known as clostridial [[myonecrosis]]. The toxin involved in gas gangrene is known as [[Clostridium perfringens alpha toxin|α-toxin]], which inserts into the plasma membrane of cells, producing gaps in the membrane which disrupt normal cellular function.<ref name=O.T.M>{{cite book | author = Warrell et al. | title = Oxford Textbook of Medicine | edition = 4th ed. | publisher = Oxford University Press | year = 2003 | id = ISBN 0-19-262922-0 }}</ref>
The action of ''C. perfringens'' on dead bodies is known to [[mortuary]] workers as [[tissue gas]] and can only be halted by [[embalming]].
==Food poisoning==
Some strains of ''C. perfringens'' produce toxins which cause [[food poisoning]] if ingested. In the United Kingdom and United States they are the third most common cause of food-borne illness, with poorly prepared meat and poultry the main culprits in harboring the bacterium.<ref name=O.T.M>{{cite book | author = Warrell et al. | title = Oxford Textbook of Medicine | edition = 4th ed. | publisher = Oxford University Press | year = 2003|id = 0-19-262922-0 }}</ref> The clostridial [[enterotoxin]] mediating the disease is often heat-resistant and can be detected in contaminated food and feces.<ref name=M.D.T>{{cite book | author = Adelman et al. | title = Current Medical Diagnosis & Treatment | edition = 45th ed. | publisher = McGraw Hill | year = 2006 | id = ISBN 0-07-147177-4 }}</ref>
Incubation time is between 8 and 16 hours after ingestion of contaminated food. Manifestions typically include abdominal cramping and diarrhea - vomiting and fever are unusual. The whole course usually resolves within 24 hours. Very rare, fatal cases of [[clostridial necrotizing enteritis]] have been known to involve "Type C" strains of the organism, which produce a potently ulcerative β-toxin.
It is likely that many cases of ''C. perfringens'' food poisoning remain sub clinical, as [[antibody|antibodies]] to the toxin are common amongst the population. This has led to the conclusion that most, if not all, of the population has experienced food poisoning due to ''C. perfringens''.<ref name=O.T.M>{{cite book | author = Warrell et al. | title = Oxford Textbook of Medicine | edition = 4th ed. | publisher = Oxford University Press | year = 2003 | id = 0-19-262922-0 }}</ref>
On July 14, 2008, Australian officials listed ''C. perfringens'' as the cause of an outbreak at Endeavour Nursing Home in Springwood, NSW where 80 individuals had become sick, and 10 later died. As of this date, the details are not clear. <ref>The Sydney Moring Hearald, smh.com.au, July 14, 2008</ref> [http://www.smh.com.au/news/national/10-dead-gastroenteritis-mystery/2008/07/13/1215887451577.html]
==Colony characteristics==
[[Image:Clostridium perfringens 01.png|thumb|right|240px|''C. perfringens'' colonies on an egg yolk [[agar plate]] showing a white precipitate]]
On [[blood agar]] plates, ''C. perfringens'' grown anaerobically produces [[β-haemolysis|β-haemolytic]], flat, spreading, rough, translucent colonies with irregular margins. A Nagler agar plate, containing 5-10% egg yolk, is used to presumptively identify strains which produce α-toxin, a diffusible [[lecithinase]] which interacts with the lipids in egg yolk to produce a characteristic precipitate around the colonies. One half of the plate is inoculated with [[antitoxin]] to act as a control in the identification.
==References==
{{reflist|2}}
==External links==
*[http://pathema.jcvi.org/cgi-bin/Clostridium/PathemaHomePage.cgi Pathema-''Clostridium'' Resource]
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