Clostridia

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Clostridia
Clostridium botulinum

Clostridium botulinum

Systematics
Domain : Bacteria (bacteria)
Department : Firmicutes
Class : Clostridia
Order : Clostridiales
Family : Clostridiaceae
Genre : Clostridia
Scientific name
Clostridium
Prazmowski 1880

Clostridia (from the Latin generic name Clostridium , from the Greek κλωστήρ "spindle") are gram-positive , obligately anaerobic , spore- forming bacteria from the Clostridiaceae family . The endospores are heat-resistant and can survive in boiling water for many hours, some at 110 ° C for about an hour. With the exception of C. perfringens , clostridia can actively move with flagella arranged peritrichally .

The bacteria are so-called environmental germs and occur everywhere ( ubiquitously ), especially in the soil and in the digestive tract (especially as normal flora in the intestines) of higher living beings. They also get into food through dust and soil particles, where they can lead to serious problems (see below ).

The genus of clostridia includes both pathogens ( pathogenic germs) and non-pathogenic species, some of which are used in biotechnology. The main pathogenic species include Clostridium botulinum (causes botulism ), Clostridioides difficile (causes colon inflammation, the so-called pseudomembranous colitis ) and Clostridium tetani (causes tetanus ). Other types cause gas burn , bradsot , intoxicating burn , and abomasum pararanoma .

Based on their preferred energy source, clostridia can be divided into three broad groups:

  1. Proteolytic clostridia: cleavage of proteins and / or conversion of amino acids in pairs
  2. Uric acid- splitting clostridia, e.g. B. C. acidi-urici
  3. Saccharolytic clostridia: fermentation of carbohydrates ( sugar , cellulose , starch )

The main fermentation products of the saccharolytic clostridia are butyric acid , acetone , butanol , carbon dioxide and molecular hydrogen (H 2 ).

Biotechnical importance

Production of organic solvents

Clostridium acetobutylicum is able to ferment sugar into the solvents acetone , 1-butanol , ethanol and the organic acids acetic acid and butyric acid. The bacterium was used for the biotic production of the organic solvents mentioned on an industrial scale until the middle of the 20th century. It was first described by the chemist Chaim Weizmann , who later became the first President of the State of Israel.

In addition, numerous other Clostridienarten for biotechnological production are used by different products or are being researched as potential producers, including the for syngas fermentation usable ljungdahlii Clostridium .

Clostridia in agriculture

Clostridia are widespread in soils. Saccharolytic clostridia (but not representatives of the other clostridia groups) are able to reduce and thus fix molecular nitrogen (N 2 ) . They are therefore referred to as diazotrophic and are therefore natural fertilizer producers in the soil. The most active N 2 fixer of the genus is Clostridium pasteurianum in anoxic sediments .

In the 10/2005 issue of the dlz agricultural magazine, there is a warning against the build-up of clostridia in agricultural biogas plants (co-fermentation plants). In such plants, liquid manure from animal husbandry and green waste from municipalities, trade and industry are usually fermented anaerobically at below 40 ° C. In this process, clostridia would find the best conditions for reproduction. The author recommends plowing in fermentation substrates and not on green areas. With the use of " effective microorganisms ", the build-up should also be reduced.

The NRW Chamber of Agriculture has warned against "scare tactics" with regard to clostridia and biogas slurry. An increase in the often problematic bacterium Clostridium perfringens has not yet been found. In accordance with the Bavarian State Agency for Agriculture , however, warnings are given against the spreading of carnivore droppings and guano (dry bird droppings) because they contain one hundred thousand times more pathogenic bacteria of the Clostridium perfringens type than in the droppings of herbivores. Here the germ count is 100 - 10,000 per 1 ml. The application of fermentation residues from biogas plants to forage plants and pastures could possibly pose a health hazard if these products are used.

The risk of botulism caused by Clostridium botulinum should also be restricted: In North Rhine-Westphalia, poultry excrement may only be used on arable land and in biogas plants, but not on grassland and field grass.

Whether cheese-damaging clostridia can be associated with biogas plants seems unlikely: Experience with two companies in North Rhine-Westphalia over 8 years even shows a particularly low level of contamination.

Medical importance

Food spoilers or poisoners

Clostridium perfringens, in particular, is known to induce enteritis caused by contaminated food . Due to their pronounced resistance to high temperatures, Clostridium endospores can survive the sterilization of canned food if the heating is insufficient. They germinate during the storage of the canned food and the clostridia multiply in them, since they do not need oxygen for their metabolism (they are obligatorily anaerobic ). Their metabolism leads to the spoilage of the canned food: The canned food is decomposed, unpleasant smelling and tasting acids are formed, the gases formed, carbon dioxide (CO 2 ) and molecular hydrogen (H 2 ), inflate the cans (so-called bombage ). Other foods such as cheese can also be destroyed by gas formation. One speaks here of the so-called late bloating . Also aseptically packaged beverage cartons with fruit juice or fruit pulp can recontamination or high spore load and inadequate pasteurization be of Swelling affected.

Medically important species of clostridia

Virulence factors

Various virulence factors occur in clostridia. Clostridium botulinum produces the botulinum toxin , which is inactivated after only 30 minutes of heating at 80 ° C. The different types hydrolytically split proteins that mediate fusion with the synaptic membrane (synaptobrevin, syntaxin , SNAP-25). This in turn inhibits the release of acetylcholine from the synapses. Clostridium tetani produces the tetanus toxin . It is released when the bacterial cell breaks down. Synaptobrevin is cleaved, and so the release of the inhibitory neurotransmitters glycine and GABA is inhibited (hence the name tetanus). Clostridium perfringens produces, among other things, the toxin alpha (= lecithinase), which destroys cell membranes, and it produces enterotoxins and pore-forming toxins . Clostridioides difficile produces toxins A (enterotoxin effect) and B (cytolytic effect).

The clostridial collagenases make up another virulence factor. With the help of this enzyme, clostridia can spread particularly quickly through the breakdown of collagen in the connective tissue of the host organism. Conversely, clostridial collagenase is used to support wound healing ( debridement ).

treatment

Penicillin , combined with clindamycin or metronidazole , as well as ampicillin , amoxicillin , ampicillin-sulbactam and amoxicillin-clavulanic acid are available as antibiotics for the treatment of infections with Clostridium species .

literature

  • Martin Dworkin, Stanley Falkow, Eugene Rosenberg, Karl-Heinz Schleifer, Erko Stackebrandt (eds.): The Prokaryotes. Vol. 4. Bacteria - Firmicutes, Cyanobacteria. 3rd ed. Springer, New York 2006. ISBN 0-387-25494-3 . doi : 10.1007 / 0-387-30744-3

Web links

Commons : Clostridia  - collection of images, videos, and audio files

Individual evidence

  1. ↑ Michael Köpke, Claudia Held, Sandra Hujer, Heiko Liesegang, Arnim Wiezer, Antje Wollherr, Armin Ehrenreich, Wolfgang Liebl, Gerhard Gottschalk , Peter Dürre: Clostridium ljungdahlii represents a microbial production platform based on syngas. Proceedings of the National Academy of Sciences of the United States (PNAS) 107 (29), July 20, 2010. Full text , PMID 20616070 .
  2. ↑ Monika Krüger , in: dlz-Agrarmagazin. 56.2005,10, p. 14. ISSN  0340-787X
  3. ↑ LfL - Umwelttechnik ( Memento of the original dated February 21, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. ( PDF ; 73 kB)  @1@ 2Template: Webachiv / IABot / www.lfl.bayern.de
  4. ↑ New rules for the import of liquid manure. ( Memento of the original from February 28, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. In: Agricultural weekly newspaper via naehrstoffboerse.de , issue 40/2007, ( PDF ; 2.4 MB) @1@ 2Template: Webachiv / IABot / www.naehrstoffboerse.de
  5. ↑ Clostridia in biogas plants - no risks for animal health and milk quality. ( Memento of the original from May 31, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. In: oekolandbau.nrw.de , May 11, 2010.  @1@ 2Template: Webachiv / IABot / www.oekolandbau.nrw.de
  6. ^ Marianne Abele-Horn: Antimicrobial Therapy. Decision support for the treatment and prophylaxis of infectious diseases. With the collaboration of Werner Heinz, Hartwig Klinker, Johann Schurz and August Stich, 2nd, revised and expanded edition. Peter Wiehl, Marburg 2009, ISBN 978-3-927219-14-4 , p. 262.
  7. ↑ LADR informs: Clostridia in food: Detection of the toxin genes of Clostridium botulinum ( Memento of the original from December 1, 2017 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , 02/2015 @1@ 2Template: Webachiv / IABot / www.ladr-lebensmittel.de
  8. ^ Marianne Abele-Horn (2009).
  9. ^ Marianne Abele-Horn (2009).
  10. ^ Marianne Abele-Horn (2009).
  11. ↑ M. Pruteanu, NP Hyland et al. a .: Degradation of the extracellular matrix components by bacterial-derived metalloproteases: implications for inflammatory bowel diseases. In: Inflammatory bowel diseases. Volume 17, Number 5, May 2011, pp. 1189-1200, ISSN  1536-4844 . doi : 10.1002 / ibd.21475 . PMID 20853433 .
  12. ↑ J. Ramundo, M. Gray: Collagenase for enzymatic debridement: a systematic review. In: Journal of wound, ostomy, and continence nursing: official publication of The Wound, Ostomy and Continence Nurses Society / WOCN. Volume 36, Number 6 Suppl, 2009 Nov-Dec, pp. S4-11, ISSN  1528-3976 . doi : 10.1097 / WON.0b013e3181bfdf83 . PMID 19918148 . (Review).
  13. ↑ Collagenase in Dupuytren's contracture: additional benefit not proven ( memento of the original from January 5, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , Report from the Institute for Quality and Efficiency in Health Care ( IQWiG ) from January 1, 2012 @1@ 2Template: Webachiv / IABot / www.iqwig.de
  14. ^ Marianne Abele-Horn (2009).