Clostridium

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Clostridium
Clostridium difficile 01.jpg
SEM micrograph of Clostridium difficile colonies from a stool sample
Scientific classification
Domain: Bacteria
Phylum: Firmicutes
Class: Clostridia
Order: Clostridiales
Family: Clostridiaceae
Genus: Clostridium
Prazmowski 1880
Selected species

C. acetobutylicum
C. argentinense
C. aerotolerans
C. baratii
C. beijerinckii
C. bifermentans
C. botulinum
C. butyricum
C. cadaveris
C. cellulolyticum
C. chauvoei
C. clostridioforme
C. colicanis
C. difficile
C. estertheticum
C. fallax
C. feseri
C. formicaceticum
C. histolyticum
C. innocuum
C. kluyveri
C. ljungdahlii
C. lavalense
C. leptum
C. methylpentosum
C. novyi
C. oedematiens
C. paraputrificum
C. perfringens (Alias: C. welchii)
C. phytofermentans
C. piliforme
C. ragsdalei
C. ramosum
C. scatologenes
C. septicum
C. sordellii
C. sporogenes
C. sticklandii
C. tertium
C. tetani
C. thermocellum
C. thermosaccharolyticum
C. tyrobutyricum

Clostridium is a genus of Gram-positive bacteria, belonging to the Firmicutes. They are obligate anaerobes capable of producing endospores.[1][2] Individual cells are rod-shaped, which gives them their name, from the Greek kloster (κλωστήρ) or spindle. These characteristics traditionally defined the genus; however many species originally classified as Clostridium have been reclassified in other genera.

Overview[edit]

Clostridium consists of around 100 species[3] that include common free-living bacteria as well as important pathogens.[4] There are five main species responsible for disease in humans.

  • C. botulinum, an organism that produces botulinum toxin in food/wound and can cause botulism.[5] Honey sometimes contains spores of Clostridium botulinum, which may cause infant botulism in humans one year old and younger. The toxin eventually paralyzes the infant's breathing muscles.[6] Adults and older children can eat honey safely, because Clostridium do not compete well with the other rapidly growing bacteria present in the gastrointestinal tract. This same toxin is known as "Botox" and is used cosmetically to paralyze facial muscles to reduce the signs of aging; it also has numerous therapeutic uses.
  • C. tetani, the causative organism of tetanus.[9] The name is derived from Ancient Greek: τέτανος tetanos “taut”, and τείνειν teinein "to stretch",[10] due to the violent spasms caused by C. tetani infection.
  • C. sordellii can cause a fatal infection in exceptionally rare cases after medical abortions.[11] Less than one case per year has been reported since 2000.[11]

Clostridium is sometimes found in raw swiftlet nests, a Chinese delicacy. Nests are washed in a sulfite solution to kill the bacteria before being exported to the U.S.[12]

Neurotoxin production is the unifying feature of the species C. botulinum. Eight types of toxins have been identified and allocated a letter (A-H).[13] Most strains produce one type of neurotoxin but strains producing multiple toxins have been described. C. botulinum producing B and F toxin types have been isolated from human botulism cases in New Mexico and California. The toxin type has been designated Bf as the type B toxin was found in excess of the type F. Similarly, strains producing Ab and Af toxins have been reported. Organisms genetically identified as other Clostridium species have caused human botulism; Clostridium butyricum producing type E toxin and Clostridium baratii producing type F toxin. The ability of C. botulinum to naturally transfer neurotoxin genes to other Clostridium species is concerning, especially in the food industry where preservation systems are designed to destroy or inhibit only C. botulinum but not other Clostridium species.

Commercial uses[edit]

C. thermocellum can utilize lignocellulosic waste and generate ethanol, thus making it a possible candidate for use in production of ethanol fuel. It also has no oxygen requirement and is thermophilic, which reduces cooling cost.

C. acetobutylicum, also known as the Weizmann organism, was first used by Chaim Weizmann to produce acetone and biobutanol from starch in 1916 for the production of gunpowder and TNT.

C. botulinum produces a potentially lethal neurotoxin that is used in a diluted form in the drug Botox, which is carefully injected to nerves in the face, which prevents the movement of the expressive muscles of the forehead, to delay the wrinkling effect of aging. It is also used to treat spasmodic torticollis and provides relief for approximately 12 to 16 weeks.[14]

C. butyricum MIYAIRI 588 strain is marketed in Japan, Korea and China for C. difficile prophylaxis due to its reported ability to interfere with the growth of that highly pathogenic organism.

The anaerobic bacterium C. ljungdahlii, recently discovered in commercial chicken wastes, can produce ethanol from single-carbon sources including synthesis gas, a mixture of carbon monoxide and hydrogen that can be generated from the partial combustion of either fossil fuels or biomass. Use of these bacteria to produce ethanol from synthesis gas has progressed to the pilot plant stage at the BRI Energy facility in Fayetteville, Arkansas.[15]

Fatty acids are converted by yeasts to long-chain dicarboxylic acids and then to 1,3-propanediol using Clostridium diolis.[citation needed]

Genes from C. thermocellum have been inserted into transgenic mice to allow the production of endoglucanase. The experiment was intended to learn more about how the digestive capacity of monogastric animals could be improved. Hall et al. published their findings in 1993.

Non-pathogenic strains of Clostridium may help in the treatment of diseases such as cancer. Research shows that Clostridium can selectively target cancer cells. Some strains can enter and replicate within solid tumours. Clostridium could, therefore, be used to deliver therapeutic proteins to tumours. This use of Clostridium has been demonstrated in a variety of preclinical models.[16]

Mixtures of Clostridium species, such as a mixtures of C. beijerinckii, C. butyricum, and species from other genera have been shown to produce biohydrogen from yeast waste.[17]

Taxonomy[edit]

This genus like several others has undergone a number of revisions with the increasing availability of genomic data. An analysis of a number of proteins from a number of members of this genus has suggested another revision.[18] The main findings of this study were:

It has been proposed to create six new genera accommodate the 78 validly described species that do not appear to be Clostridia. These genera are: Erysipelatoclostridium, Gottschalkia, Lachnoclostridium, Peptoclostridium, Ruminiclostridium and Tyzzerella.

Under this proposal the species Clostridium difficile would become Peptoclostridium difficile.

References[edit]

  1. ^ Ryan KJ, Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. ISBN 0-8385-8529-9. 
  2. ^ Bruggemann H, Gottschalk G (editors). (2009). Clostridia: Molecular Biology in the Post-genomic Era. Caister Academic Press. ISBN 978-1-904455-38-7. 
  3. ^ UK Standards for Microbiology Investigations (October 10, 2011). "Identification of Clostridium Species". Standards Unit, Health Protection Agency. p. 7. 8. Retrieved November 3, 2013. 
  4. ^ Wells CL, Wilkins TD (1996). Clostridia: Sporeforming Anaerobic Bacilli in: Baron's Medical Microbiology (Baron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. ISBN 0-9631172-1-1. 
  5. ^ Wells CL, Wilkins TD (1996). Botulism and Clostridium botulinum in: Baron's Medical Microbiology (Baron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. ISBN 0-9631172-1-1. 
  6. ^ Tanzi MG, Gabay MP (2002). "Association between honey consumption and infant botulism". Pharmacotherapy 22 (11): 1479–83. doi:10.1592/phco.22.16.1479.33696. PMID 12432974. 
  7. ^ Wells CL, Wilkins TD (1996). Antibiotic-Associated Diarrhea, Pseudomembranous Colitis, and Clostridium difficile in: Baron's Medical Microbiology (Baron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. ISBN 0-9631172-1-1. 
  8. ^ Wells CL, Wilkins TD (1996). Other Pathogenic Clostridia Food Poisoning and Clostridium perfringens in: Baron's Medical Microbiology (Baron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. ISBN 0-9631172-1-1. 
  9. ^ Wells CL, Wilkins TD (1996). Tetanus and Clostribium tetani in: Baron's Medical Microbiology (Baron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. ISBN 0-9631172-1-1. 
  10. ^ tetanus. CollinsDictionary.com. Collins English Dictionary - Complete & Unabridged 11th Edition. Retrieved October 01, 2012
  11. ^ a b Meites E, Zane S, Gould C (2010). "Fatal Clostridium sordellii infections after medical abortions". New England Journal of Medicine 363 (14): 1382–3. doi:10.1056/NEJMc1001014. 
  12. ^ Valli, Eric and Diane Summers (January 1990). "The Nest Gatherers of Tiger Cave" in National Geographic.
  13. ^ http://www.ncbi.nlm.nih.gov/pubmed/24106295
  14. ^ Velickovic M, Benabou R, Brin MF. Cervical dystonia pathophysiology and treatment options" Drugs 2001;61:1921–1943.
  15. ^ "Providing for a Sustainable Energy Future". Bioengineering Resources, inc. Retrieved 21 May 2007. 
  16. ^ Mengesha et al. (2009). "Clostridia in Anti-tumor Therapy". Clostridia: Molecular Biology in the Post-genomic Era. Caister Academic Press. ISBN 978-1-904455-38-7. 
  17. ^ Chou, Chia-Hung; Chang-Lung Han, Jui-Jen Chang, Jiunn-Jyi Lay (October 2011). "Co-culture of Clostridium beijerinckii L9, Clostridium butyricum M1 and Bacillus thermoamylovorans B5 for converting yeast waste into hydrogen". International Journal of Hydrogen Energy 36 (21): 13972–13983. doi:10.1016/j.ijhydene.2011.03.067. 
  18. ^ Yutin N, Galperin MY (2013) A genomic update on Clostridial phylogeny: Gram-negative spore formers and other misplaced Clostridia. Environ Microbiol doi:10.1111/1462-2920.12173

External links[edit]