Fusobacterium nucleatum

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Fusobacterium nucleatum
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Bacteria
Phylum: Fusobacteriota
Class: Fusobacteriia
Order: Fusobacteriales
Family: Fusobacteriaceae
Genus: Fusobacterium
Species:
F. nucleatum
Binomial name
Fusobacterium nucleatum
Knorr, 1922

Fusobacterium nucleatum is a Gram-negative, anaerobic bacterium, commensal to the human oral cavity, that plays a role in periodontal disease. This organism is commonly recovered from different monocultured microbial and mixed infections in humans and animals. In health and disease, it is a key component of periodontal plaque due to its abundance and its ability to coaggregate with other bacteria species in the oral cavity. [1] [2]

Contents

Preterm births

Research implicates periodontal disease caused by F. nucleatum with preterm births in humans. In many studies, F. nucleatum cells have been isolated from the amniotic fluid, placenta, and chorioamnionic membranes of women delivering prematurely. Moreover, laboratory mice intravenously inoculated with F. nucleatum have been found to deliver prematurely, and the pathology of the infection seems to mirror observations in humans. [3] Together, this research provides evidence for a possible causal connection between F. nucleatum-caused periodontal disease and at least some cases of preterm delivery. F. nucleatum can also be isolated from the vaginal microbiome, especially in women with a condition known as bacterial vaginosis. [4] Both F. nucleatum vaginal colonization and bacterial vaginosis also have been linked with preterm birth and infections within the uterus. [5] Thus, preterm birth arising by infections caused by F. nucleatum could also arise from invasive infection into the uterine tissue originating from the colonized vagina.[ citation needed ]

Colon cancer

F. nucleatum has a demonstrated association with colorectal cancer. Fusobacterium species have been found at higher quantities in certain types of colon tumors than in surrounding colon tissue or the colons of healthy individuals, but whether this is an indirect correlation or a causal link is unclear. A distinguishing mechanism has been described by which F. nucleatum creates a pro-inflammatory environment which is conducive to tumor growth through the recruitment of tumor-infiltrating immune cells, which, unlike other bacteria linked to colorectal carcinoma, does not exacerbate other pathological processes such as colitis, enteritis and inflammatory-associated intestinal carcinogenesis. This suggests direct and specific carcinogenesis. [6] F. nucleatum can bind to host tissue E-cadherins via a FadA, an outer membrane protein. [7] Additionally, a surface expressed lectin called Fap2 mediates F. nucleatum adherence to colorectal cancer cells that express Gal/GalNAc moieties on their surface. Binding via Fap2 has also been shown to up-regulate production of cytokines associated with higher rates of metastasis. [8]

Natural competence

Type IV pili facilitate natural competence in F. nucleatum [9] . Natural competence involves three principal stages: (1) Uptake of exogenous DNA and transport to the cytoplasm, (2) homologous DNA that has been taken up can integrate into the recipient cell genome by homologous recombination, and (3) the integrated exogenous DNA can express gene functions [9] .

See also

Related Research Articles

<span class="mw-page-title-main">Bacterial vaginosis</span> Excessive growth of bacteria in the vagina

Bacterial vaginosis (BV) is an infection of the vagina caused by excessive growth of bacteria. Common symptoms include increased vaginal discharge that often smells like fish. The discharge is usually white or gray in color. Burning with urination may occur. Itching is uncommon. Occasionally, there may be no symptoms. Having BV approximately doubles the risk of infection by a number of sexually transmitted infections, including HIV/AIDS. It also increases the risk of early delivery among pregnant women.

<i>Fusobacterium</i> Genus of bacteria

Fusobacterium is a genus of obligate anaerobic, Gram-negative, non-sporeforming bacteria belonging to Gracilicutes. Individual cells are slender, rod-shaped bacilli with pointed ends. Fusobacterium was discovered in 1900 by Courmont and Cade and is common in the flora of humans.

<span class="mw-page-title-main">Metronidazole</span> Antibiotic and antiprotozoal medication

Metronidazole, sold under the brand name Flagyl among others, is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat pelvic inflammatory disease, endocarditis, and bacterial vaginosis. It is effective for dracunculiasis, giardiasis, trichomoniasis, and amebiasis. It is an option for a first episode of mild-to-moderate Clostridioides difficile colitis if vancomycin or fidaxomicin is unavailable. Metronidazole is available orally, as a cream or gel, and by slow intravenous infusion.

Vaginitis, also known as vulvovaginitis, is inflammation of the vagina and vulva. Symptoms may include itching, burning, pain, discharge, and a bad smell. Certain types of vaginitis may result in complications during pregnancy.

<span class="mw-page-title-main">Fusobacteriota</span> Phylum of Gram-negative bacteria

Fusobacteriota are obligately anaerobic non-sporeforming Gram-negative bacilli. Since the first reports in the late nineteenth century, various names have been applied to these organisms, sometimes with the same name being applied to different species. More recently, not only have there been changes to the nomenclature, but also attempts to differentiate between species which are believed to be either pathogenic or commensal or both. Because of their asaccharolytic nature, and a general paucity of positive results in routine biochemical tests, laboratory identification of the Fusobacteriota has been difficult. However, the application of novel molecular biological techniques to taxonomy has established a number of new species, together with the subspeciation of Fusobacterium necrophorum and F. nucleatum, and provided new methods for identification. The involvement of Fusobacteriota in a wide spectrum of human infections causing tissue necrosis and septicaemia has long been recognised, and, more recently, their importance in intra-amniotic infections, premature labour and tropical ulcers has been reported.

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.

Fusobacterium polymorphum is a subspecies strain of the anaerobic, Gram-negative bacterium, Fusobacterium nucleatum. Originally, it was isolated from the plaque samples of individuals diagnosed with periodontitis and has been phylogenetically identified as its own distinct sub-group, separate from its previously studied sister strains. Research studies have also linked this subspecies to human diseases, such as fatal sepsis and inflammatory periodontal disease.

Porphyromonas gingivalis belongs to the phylum Bacteroidota and is a nonmotile, Gram-negative, rod-shaped, anaerobic, pathogenic bacterium. It forms black colonies on blood agar.

<span class="mw-page-title-main">Vaginal flora</span> Microorganisms present in the vagina

Vaginal flora, vaginal microbiota or vaginal microbiome are the microorganisms that colonize the vagina. They were discovered by the German gynecologist Albert Döderlein in 1892 and are part of the overall human flora. The amount and type of bacteria present have significant implications for an individual's overall health. The primary colonizing bacteria of a healthy individual are of the genus Lactobacillus, such as L. crispatus, and the lactic acid they produce is thought to protect against infection by pathogenic species.

Aggregatibacter actinomycetemcomitans is a Gram-negative, facultative anaerobe, nonmotile bacterium that is often found in association with localized aggressive periodontitis, a severe infection of the periodontium. It is also suspected to be involved in chronic periodontitis. Less frequently, A. actinomycetemcomitans is associated with nonoral infections such as endocarditis. Its role in aggressive periodontitis was first discovered by Danish-born periodontist Jørgen Slots, a professor of dentistry and microbiology at the University of Southern California School of Dentistry.

Treponema denticola is a Gram-negative, obligate anaerobic, motile and highly proteolytic spirochete bacterium. It is one of four species of oral spirochetes to be reliably cultured, the others being Treponema pectinovorum, Treponema socranskii and Treponema vincentii. T. denticola dwells in a complex and diverse microbial community within the oral cavity and is highly specialized to survive in this environment. T. denticola is associated with the incidence and severity of human periodontal disease. Treponema denticola is one of three bacteria that form the Red Complex, the other two being Porphyromonas gingivalis and Tannerella forsythia. Together they form the major virulent pathogens that cause chronic periodontitis. Having elevated T. denticola levels in the mouth is considered one of the main etiological agents of periodontitis. T. denticola is related to the syphilis-causing obligate human pathogen, Treponema pallidum subsp. pallidum. It has also been isolated from women with bacterial vaginosis.

Prevotella is a genus of Gram-negative bacteria.

Prevotella intermedia is a gram-negative, obligate anaerobic pathogenic bacterium involved in periodontal infections, including gingivitis and periodontitis, and often found in acute necrotizing ulcerative gingivitis. It is commonly isolated from dental abscesses, where obligate anaerobes predominate.

Tannerella forsythia is an anaerobic, Gram-negative bacterial species of the Bacteroidota phylum. It has been implicated in periodontal diseases and is a member of the red complex of periodontal pathogens. T. forsythia was previously named Bacteroides forsythus and Tannerella forsythensis.

Periodontal pathogens are bacteria that have been shown to significantly contribute to periodontitis.

Anaerobic infections are caused by anaerobic bacteria. Obligately anaerobic bacteria do not grow on solid media in room air ; facultatively anaerobic bacteria can grow in the presence or absence of air. Microaerophilic bacteria do not grow at all aerobically or grow poorly, but grow better under 10% carbon dioxide or anaerobically. Anaerobic bacteria can be divided into strict anaerobes that can not grow in the presence of more than 0.5% oxygen and moderate anaerobic bacteria that are able of growing between 2 and 8% oxygen. Anaerobic bacteria usually do not possess catalase, but some can generate superoxide dismutase which protects them from oxygen.

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.

<span class="mw-page-title-main">Uterine microbiome</span>

The uterine microbiome is the commensal, nonpathogenic, bacteria, viruses, yeasts/fungi present in a healthy uterus, amniotic fluid and endometrium and the specific environment which they inhabit. It has been only recently confirmed that the uterus and its tissues are not sterile. Due to improved 16S rRNA gene sequencing techniques, detection of bacteria that are present in low numbers is possible. Using this procedure that allows the detection of bacteria that cannot be cultured outside the body, studies of microbiota present in the uterus are expected to increase.

References

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  6. Kostic AD, Chun E, Robertson L, Glickman JN, Gallini CA, Michaud M, et al. (August 2013). "Fusobacterium nucleatum potentiates intestinal tumorigenesis and modulates the tumor-immune microenvironment". Cell Host & Microbe. 14 (2): 207–15. doi:10.1016/j.chom.2013.07.007. PMC   3772512 . PMID   23954159.
  7. Guo, Pin; Tian, Zibin; Kong, Xinjuan; Yang, Lin; Shan, Xinzhi; Dong, Bingzi; Ding, Xueli; Jing, Xue; Jiang, Chen; Jiang, Na; Yu, Yanan (2020-09-29). "FadA promotes DNA damage and progression of Fusobacterium nucleatum-induced colorectal cancer through up-regulation of chk2". Journal of Experimental & Clinical Cancer Research. 39 (1): 202. doi: 10.1186/s13046-020-01677-w . ISSN   1756-9966. PMC   7523382 . PMID   32993749.
  8. Casasanta, Michael A.; Yoo, Christopher C.; Udayasuryan, Barath; Sanders, Blake E.; Umaña, Ariana; Zhang, Yao; Peng, Huaiyao; Duncan, Alison J.; Wang, Yueying (2020-01-16). "Fusobacterium nucleatum host cell binding and invasion induces IL-8 and CXCL1 secretion that drives colorectal cancer cell migration". doi:10.1101/2020.01.15.907931. S2CID   213030137 . Retrieved 2022-07-18.{{cite journal}}: Cite journal requires |journal= (help)
  9. 1 2 Sanders BE, Umaña A, Nguyen TTD, Williams KJ, Yoo CC, Casasanta MA, Wozniak B, Slade DJ. Type IV pili facilitated natural competence in Fusobacterium nucleatum. Anaerobe. 2023 Aug;82:102760. doi: 10.1016/j.anaerobe.2023.102760. Epub 2023 Jul 13. PMID: 37451427