Clostridia

Clostridia
Clostridium botulinum
Scientific classification Edit this classification
Domain: Bacteria
Phylum: Bacillota
Class: Clostridia
Rainey 2010
Orders
Synonyms
  • "Clostridiia" Cavalier-Smith 2020
  • "Halanaerobiia" Cavalier-Smith 2020
  • "Desulfotomaculia" Watanabe et al. 2019
  • "Natranaerobiia" Sorokin et al. 2021

The Clostridia are a highly polyphyletic class of Bacillota, including Clostridium and other similar genera. They are distinguished from the Bacilli by lacking aerobic respiration. They are obligate anaerobes and oxygen is toxic to them. Species of the class Clostridia are often but not always Gram-positive (see Halanaerobium) and have the ability to form spores.[1] Studies show they are not a monophyletic group, and their relationships are not entirely certain. Currently, most are placed in a single order called Clostridiales, but this is not a natural group and is likely to be redefined in the future.

Most species of the genus Clostridium are saprophytic organisms that ferment plant polysaccharides [2] and are found in many places in the environment, most notably the soil. However, the genus does contain some human pathogens (outlined below). The toxins produced by certain members of the genus Clostridium are among the most dangerous known. Examples are tetanus toxin (known as tetanospasmin) produced by C. tetani and botulinum toxin produced by C. botulinum. Some species have been isolated from women with bacterial vaginosis.[3]

  1. ^ Baron, Samuel (1996). Medical Microbiology (4th ed.). Galveston: Universirt of Texas Medical Branch. ISBN 0-9631172-1-1.
  2. ^ Boutard, Magali; Cerisy, Tristan; Nogue, Pierre-Yves (2014). "Functional diversity of carbohydrate-active enzymes enabling a bacterium to ferment plant biomass". PLOS Genetics. 10 (11): e1004773. doi:10.1371/journal.pgen.1004773. PMC 4230839. PMID 25393313.
  3. ^ Africa, Charlene; Nel, Janske; Stemmet, Megan (2014). "Anaerobes and Bacterial Vaginosis in Pregnancy: Virulence Factors Contributing to Vaginal Colonisation". International Journal of Environmental Research and Public Health. 11 (7): 6979–7000. doi:10.3390/ijerph110706979. ISSN 1660-4601. PMC 4113856. PMID 25014248.