Clostridia

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Clostridia
Clostridium botulinum.jpg
Clostridium botulinum
Scientific classification OOjs UI icon edit-ltr.svg
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.

Contents

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]

Species

Notable species of this class include:[ citation needed ]

Heliobacteria and Christensenella are also members of the class Clostridia.

Some of the enzymes produced by this group are used in bioremediation.

Phylogeny

The currently accepted taxonomy based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) [4] and the National Center for Biotechnology Information (NCBI). [5]

16S rRNA based LTP_08_2023 [6] [7] [8] 120 marker proteins based GTDB 08-RS214 [9] [10] [11]
Firmicutes 3  

♦ Paraphyletic "Clostridiia"

Bacillota E 
Bacillota G
"Halanaerobiaeota"

"Halanaerobiia" ♦

Bacillota A 

"Thermosediminibacteria"

"Thermoanaerobacteria"

Clostridiia s.s. (incl. Tissierellia)

Epidemiology

Since they are commonly found in soils and in microbiota of humans and animals, Clostridia wounds and infections are found worldwide. Host defenses against the microbe are nearly absent, and very little innate immunity exists, if any. Clostridia can be diagnosed by recognizing the characteristics of the lesion of the infection along with Gram stains of the tissue and bacterial culture. [1] Although the body does not have adequate defenses alone, this microbe can be controlled with the help of antibiotics, like penicillin, and tissue debridement for the more severe cases.[ citation needed ]

Clostridia and health

Clostridia bacteria are commonly found in the gut microbiome.[ medical citation needed ]

Clostridioides difficile

Overuse of antibiotics can cause imbalance of the gut microbiome, leading to overgrowth of the species Clostridioides difficile causing a serious infection (CDI). [12] Effects of this infection include severe diarrhea and the severity of many bowel related diseases is also increased as a result of the infection. Other Clostridium bacteria in the gut have been linked to brain connectivity and healthy function. [13]

Patients that have been subjected to fecal microbiota transplants to treat their CDI have seen improvements in their mood and mental health. [12] This preliminary research seems to suggest a tentative link between the presence of Clostridia in the gut microbiome and overall mental health, with gut microbiome transplants as an avenue of future research into novel treatments for certain psychiatric disorders.[ citation needed ]

See also

Related Research Articles

<span class="mw-page-title-main">Human microbiome</span> Microorganisms in or on human skin and biofluids

The human microbiome is the aggregate of all microbiota that reside on or within human tissues and biofluids along with the corresponding anatomical sites in which they reside, including the gastrointestinal tract, skin, mammary glands, seminal fluid, uterus, ovarian follicles, lung, saliva, oral mucosa, conjunctiva, and the biliary tract. Types of human microbiota include bacteria, archaea, fungi, protists, and viruses. Though micro-animals can also live on the human body, they are typically excluded from this definition. In the context of genomics, the term human microbiome is sometimes used to refer to the collective genomes of resident microorganisms; however, the term human metagenome has the same meaning.

<span class="mw-page-title-main">Bacillota</span> Phylum of bacteria

Bacillota is a phylum of bacteria, most of which have gram-positive cell wall structure. The renaming of phyla such as Firmicutes in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature.

<i>Clostridium</i> Genus of bacteria, which includes several human pathogens

Clostridium is a genus of anaerobic, Gram-positive bacteria. Species of Clostridium inhabit soils and the intestinal tracts of animals, including humans. This genus includes several significant human pathogens, including the causative agents of botulism and tetanus. It also formerly included an important cause of diarrhea, Clostridioides difficile, which was reclassified into the Clostridioides genus in 2016.

<i>Clostridioides difficile</i> infection Disease caused by C. difficile bacteria

Clostridioides difficile infection, also known as Clostridium difficile infection, is a symptomatic infection due to the spore-forming bacterium Clostridioides difficile. Symptoms include watery diarrhea, fever, nausea, and abdominal pain. It makes up about 20% of cases of antibiotic-associated diarrhea. Antibiotics can contribute to detrimental changes in gut microbiota; specifically, they decrease short-chain fatty acid absorption which results in osmotic, or watery, diarrhea. Complications may include pseudomembranous colitis, toxic megacolon, perforation of the colon, and sepsis.

<i>Clostridium perfringens</i> Species of bacterium

Clostridium perfringens is a Gram-positive, bacillus (rod-shaped), anaerobic, spore-forming pathogenic bacterium of the genus Clostridium. 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. It has the shortest reported generation time of any organism at 6.3 minutes in thioglycolate medium.

<span class="mw-page-title-main">Gas gangrene</span> Human bacterial infection

Gas gangrene is a bacterial infection that produces tissue gas in gangrene. This deadly form of gangrene usually is caused by Clostridium perfringens bacteria. About 1,000 cases of gas gangrene are reported yearly in the United States.

<span class="mw-page-title-main">Gut microbiota</span> Community of microorganisms in the gut

Gut microbiota, gut microbiome, or gut flora are the microorganisms, including bacteria, archaea, fungi, and viruses, that live in the digestive tracts of animals. The gastrointestinal metagenome is the aggregate of all the genomes of the gut microbiota. The gut is the main location of the human microbiome. The gut microbiota has broad impacts, including effects on colonization, resistance to pathogens, maintaining the intestinal epithelium, metabolizing dietary and pharmaceutical compounds, controlling immune function, and even behavior through the gut–brain axis.

<span class="mw-page-title-main">Fecal microbiota transplant</span> Process of transplantation of fecal bacteria from a healthy individual into a recipient

Fecal microbiota transplant (FMT), also known as a stool transplant, is the process of transferring fecal bacteria and other microbes from a healthy individual into another individual. FMT is an effective treatment for Clostridioides difficile infection (CDI). For recurrent CDI, FMT is more effective than vancomycin alone, and may improve the outcome after the first index infection.

Dysbiosis is characterized by a disruption to the microbiome resulting in an imbalance in the microbiota, changes in their functional composition and metabolic activities, or a shift in their local distribution. For example, a part of the human microbiota such as the skin flora, gut flora, or vaginal flora, can become deranged, with normally dominating species underrepresented and normally outcompeted or contained species increasing to fill the void. Similar to the human gut microbiome, diverse microbes colonize the plant rhizosphere, and dysbiosis in the rhizosphere, can negatively impact plant health. Dysbiosis is most commonly reported as a condition in the gastrointestinal tract or plant rhizosphere.

<i>Clostridium tetani</i> Common soil bacterium and the causative agent of tetanus

Clostridium tetani is a common soil bacterium and the causative agent of tetanus. Vegetative cells of Clostridium tetani are usually rod-shaped and up to 2.5 μm long, but they become enlarged and tennis racket- or drumstick-shaped when forming spores. C. tetani spores are extremely hardy and can be found globally in soil or in the gastrointestinal tract of animals. If inoculated into a wound, C. tetani can grow and produce a potent toxin, tetanospasmin, which interferes with motor neurons, causing tetanus. The toxin's action can be prevented with tetanus toxoid vaccines, which are often administered to children worldwide.

Prevotella is a genus of Gram-negative bacteria.

Microbial toxins are toxins produced by micro-organisms, including bacteria, fungi, protozoa, dinoflagellates, and viruses. Many microbial toxins promote infection and disease by directly damaging host tissues and by disabling the immune system. Endotoxins most commonly refer to the lipopolysaccharide (LPS) or lipooligosaccharide (LOS) that are in the outer plasma membrane of Gram-negative bacteria. The botulinum toxin, which is primarily produced by Clostridium botulinum and less frequently by other Clostridium species, is the most toxic substance known in the world. However, microbial toxins also have important uses in medical science and research. Currently, new methods of detecting bacterial toxins are being developed to better isolate and understand these toxins. Potential applications of toxin research include combating microbial virulence, the development of novel anticancer drugs and other medicines, and the use of toxins as tools in neurobiology and cellular biology.

Clostridium novyi (oedematiens) a Gram-positive, endospore- forming, obligate anaerobic bacteria of the class Clostridia. It is ubiquitous, being found in the soil and faeces. It is pathogenic, causing a wide variety of diseases in humans and animals.

<span class="mw-page-title-main">Fidaxomicin</span> Antibiotic

Fidaxomicin, sold under the brand name Dificid among others, is the first member of a class of narrow spectrum macrocyclic antibiotic drugs called tiacumicins. It is a fermentation product obtained from the actinomycete Dactylosporangium aurantiacum subspecies hamdenesis. Fidaxomicin is minimally absorbed into the bloodstream when taken orally, is bactericidal, and selectively eradicates pathogenic Clostridioides difficile with relatively little disruption to the multiple species of bacteria that make up the normal, healthy intestinal microbiota. The maintenance of normal physiological conditions in the colon may reduce the probability of recurrence of Clostridioides difficile infection.

Megasphaera is a genus of Bacillota bacteria classified within the class Negativicutes.

<span class="mw-page-title-main">Erysipelotrichia</span> Class of bacteria

The Erysipelotrichia are a class of bacteria of the phylum Bacillota. Species of this class are known to be common in the gut microbiome, as they have been isolated from swine manure and increase in composition of the mouse gut microbiome for mice switched to diets high in fat.

Bacteriotherapy is the purposeful use of bacteria or their products in treating an illness. Forms of bacteriotherapy include the use of probiotics, microorganisms that provide health benefits when consumed; fecal matter transplants (FMT) /intestinal microbiota transplant (IMT), the transfer of gut microorganisms from the fecal matter of healthy donors to recipient patients to restore microbiota; or synbiotics which combine prebiotics, indigestible ingredients that promote growth of beneficial microorganisms, and probiotics. Through these methods, the gut microbiota, the community of 300-500 microorganism species that live in the digestive tract of animals aiding in digestion, energy storage, immune function and protection against pathogens, can be recolonized with favorable bacteria, which in turn has therapeutic effects.

<i>Clostridioides difficile</i> Species of bacteria

Clostridioides difficile is a bacterium known for causing serious diarrheal infections, and may also cause colon cancer. It is known also as C. difficile, or C. diff, and is a Gram-positive species of spore-forming bacteria. Clostridioides spp. are anaerobic, motile bacteria, ubiquitous in nature and especially prevalent in soil. Its vegetative cells are rod-shaped, pleomorphic, and occur in pairs or short chains. Under the microscope, they appear as long, irregular cells with a bulge at their terminal ends. Under Gram staining, C. difficile cells are Gram-positive and show optimum growth on blood agar at human body temperatures in the absence of oxygen. C. difficile is catalase- and superoxide dismutase-negative, and produces up to three types of toxins: enterotoxin A, cytotoxin B and Clostridioides difficile transferase. Under stress conditions, the bacteria produce spores that are able to tolerate extreme conditions that the active bacteria cannot tolerate.

The vaginal flora in pregnancy, or vaginal microbiota in pregnancy, is different from the vaginal flora before sexual maturity, during reproductive years, and after menopause. A description of the vaginal flora of pregnant women who are immunocompromised is not covered in this article. The composition of the vaginal flora significantly differs in pregnancy. Bacteria or viruses that are infectious most often have no symptoms.

Clostridium scindens is a species of bacteria in the genus Clostridium that are found in the human gut.

References

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  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.
  4. J. P. Euzéby. "Clostridia". List of Prokaryotic names with Standing in Nomenclature (LPSN). Retrieved 20 June 2022.
  5. Sayers; et al. "Clostridia". National Center for Biotechnology Information (NCBI) taxonomy database. Retrieved 20 June 2022.
  6. "The LTP" . Retrieved 20 November 2023.
  7. "LTP_all tree in newick format" . Retrieved 20 November 2023.
  8. "LTP_08_2023 Release Notes" (PDF). Retrieved 20 November 2023.
  9. "GTDB release 08-RS214". Genome Taxonomy Database . Retrieved 10 May 2023.
  10. "bac120_r214.sp_label". Genome Taxonomy Database . Retrieved 10 May 2023.
  11. "Taxon History". Genome Taxonomy Database . Retrieved 10 May 2023.
  12. 1 2 Jalanka, J.; Hillamaa, A.; Satokari, R.; Mattila, E.; Anttila, V.-J.; Arkkila, P. (2018). "The long-term effects of faecal microbiota transplantation for gastrointestinal symptoms and general health in patients with recurrent Clostridium difficile infection". Alimentary Pharmacology & Therapeutics. 47 (3): 371–379. doi: 10.1111/apt.14443 . ISSN   1365-2036. PMID   29226561.
  13. Labus, Jennifer S.; Hsiao, Elaine; Tap, Julien; Derrien, Muriel; Gupta, Arpana; Le Nevé, Boris; Brazeilles, Rémi; Grinsvall, Cecilia; Ohman, Lena; Törnblom, Hans; Tillisch, Kirsten; Simren, Magnus; Mayer, Emeran A. (2017). "Clostridia from the Gut Microbiome are Associated with Brain Functional Connectivity and Evoked Symptoms in IBS". Gastroenterology. 152 (5): S40. doi:10.1016/S0016-5085(17)30496-1.