Fusobacterium is a genus of obligate anaerobic, Gram-negative, 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.

Strains of Fusobacterium can cause several human diseases and infections, including periodontal diseases,

Lemierre's syndrome, oral, head, and neck infections, as well as colorectal cancer and topical skin ulcers.

It has been tied to HIV infection and suboptimal immune recovery. Detection of Fusobacterium is typically through surgical retrieval of tissue, fecal tests, or blood tests in patients showing symptoms. Early detection is preferred and helps to prevent further disease progression. There are thirteen described Fusobacterium strains; the predominant one affecting humans is F. nucleatum, followed by F. necrophorum, which also affects animals, mainly cattle.

Background

History

Although the genus was not discovered until 1900 by Courmont and Cade, The genus was proposed by Knorr in 1923. Fusobacterium has been classically considered a normal part of the human oral, gastrointestinal, and female genital flora, which is why infections are not commonly seen. Research of colon cancer has also shown an overrepresentation of Fusobacterium, both in feces of patients and tumor tissue itself. Fusobacterium has also been seen increased in individuals infected with HIV as well as in individuals with suboptimal immune recovery as compared to patients who were not infected and had optimal responses.

Sources of other species of Fusobacterium

Source: It is usually susceptible to clindamycin, while approximately 20% of the clinical strains are resistant to penicillin. In contrast to Bacteroides spp., Fusobacterium has a potent lipopolysaccharide.

Taxonomy

Current species

Fusobacterium is divided into 13 different species, two of which each have their own set of subspecies (F. nucleatum and F. necrophorum).

! colspan=1 | 120 marker proteins based GTDB 10-RS226

|-

| style="vertical-align:top|

|

|}

Unassigned Fusobacterium:

  • "F. paranimalis" <small>Sivertsen et al. 2025</small>

See also

  • Altered Schaedler flora
  • List of bacteria genera
  • List of bacterial orders

References

  • Anaerobic Gram-Negative Bacilli chapter in Baron's Medical Microbiology (online at the NCBI bookshelf).
  • Fusobacterium From MicrobeWiki, the student-edited microbiology resource