| Clostridioides | |
|---|---|
 | |
| SE micrograph of Clostridioides difficile colonies from a stool sample | |
Scientific classification  | |
| Domain: | Bacteria |
| Phylum: | Bacillota |
| Class: | Clostridia |
| Order: | Eubacteriales |
| Family: | Peptostreptococcaceae |
| Genus: | Clostridioides Lawson and Rainey (2016) |
| Selected species | |
Clostridioides is a genus of Gram-positive bacteria, which includes Clostridioides difficile , a human pathogen causing an infectious diarrhea.
The genus Clostridioides was created to describe a few species formerly in the genus Clostridium which have been shown to be their own genetically distinct genus using 16S rRNA gene sequencing analysis. [1] However, both names are still in use and valid under the International Code of Nomenclature of Prokaryotes. [2]
They are obligate anaerobes capable of producing endospores. The normal, reproducing cells of Clostridioides, called the vegetative form, are rod-shaped, which gives them their name, from the Greek κλωστήρ or spindle. Clostridioides endospores, like Clostridium endospores, have a distinct bowling pin or bottle shape, distinguishing them from other bacterial endospores, which are usually ovoid in shape.[ citation needed ]
The Bacillota are 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.
Clostridium is a genus of anaerobic, Gram-positive bacteria. Species of Clostridium inhabit soils and the intestinal tract 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.
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.
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.
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 and have the ability to form spores. 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.
Heyndrickxia coagulans is a lactic acid–forming bacterial species. This species was transferred to Weizmannia in 2020, then to Heyndrickxia in 2023.
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.
Defensin, alpha 5 (DEFA5) also known as human alpha defensin 5 (HD5) is a protein that in humans is encoded by the DEFA5 gene. DEFA5 is expressed in the Paneth cells of the ileum.
Clostridium difficile toxin B is a cytotoxin produced by the bacteria Clostridioides difficile, formerly known as Clostridium difficile. It is one of two major kinds of toxins produced by C. difficile, the other being a related enterotoxin. Both are very potent and lethal.
Clostridium difficile toxin A (TcdA) is a toxin generated by Clostridioides difficile, formerly known as Clostridium difficile. It is similar to Clostridium difficile Toxin B. The toxins are the main virulence factors produced by the gram positive, anaerobic, Clostridioides difficile bacteria. The toxins function by damaging the intestinal mucosa and cause the symptoms of C. difficile infection, including pseudomembranous colitis.
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.
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.
Acetoanaerobium sticklandii is an anaerobic, motile, gram-positive bacterium. It was first isolated in 1954 from the black mud of the San Francisco Bay Area by T.C. Stadtman, who also named the species. A. sticklandii is not pathogenic in humans.
Cadazolid is an experimental antibiotic of the oxazolidinone class made by Actelion Pharmaceuticals Ltd. which is effective against Clostridium difficile, a major cause of drug resistant diarrhea in the elderly. Current drug treatments for this infection involve orally delivered antibiotics, principally fidaxomicin, metronidazole and vancomycin; the last two drugs are the principal therapeutic agents in use, but fail in approximately 20 to 45% of the cases. The drug works by inhibiting synthesis of proteins in the bacteria, thus inhibiting the production of toxins and the formation of spores. Cadazolid progressed through to Phase III clinical trials, but in its financial results for Q1 2018, Idorsia mentions that Actelion informed them that "following completion of Phase 3 data analysis of cadazolid - it has decided to discontinue the development of the compound."
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.
Ridinilazole is an investigational small molecule antibiotic being evaluated for oral administration to treat Clostridioides difficile infection (CDI). In vitro, it is bactericidal against C. difficile and suppresses bacterial toxin production; the mechanism of action is thought to involve inhibition of cell division. It has properties which are desirable for the treatment of CDI, namely that it is a narrow-spectrum antibiotic which exhibits activity against C. difficile while having little impact on other normal intestinal flora and that it is only minimally absorbed systemically after oral administration. At the time ridinilazole was developed, there were only three antibiotics in use for treating CDI: vancomycin, fidaxomicin, and metronidazole. The recurrence rate of CDI is high, which has spurred research into other treatment options with the aim to reduce the rate of recurrence.
Clostridium scindens is a species of bacteria in the genus Clostridium that are found in the human gut.
Proteobiotics are natural metabolites which are produced by fermentation process of specific probiotic strains. These small oligopeptides were originally discovered in and isolated from culture media used to grow probiotic bacteria and may account for some of the health benefits of probiotics.
Caldibacillus is a facultative anaerobe genus of bacteria that stains Gram-positive from the family of Bacillaceae. The type species of this genus is Caldibacillus debilis.