Fusobacterium

# Overview
Fusobacterium is a genus of filamentous, anaerobic, Gram-negative bacteria, similar to Bacteroides.
Fusobacterium contribute to several human diseases, including periodontal diseases, Lemierre's syndrome, and tropical skin ulcers. Although older resources have stated that Fusobacterium is a common occurrence in the human oropharynx, the current consensus is that Fusobacterium should always be treated as a pathogen.

# Notable Species

## F. necrophorum
Fusobacterium necrophorum is the species of Fusobacterium that is responsible for Lemierre's syndrome, and appears to be responsible for 10% of all acute sore throats and 21% of all recurring sore throats, with the remainder being caused by Group A streptococci or viruses.
Other complications from F. necrophorum include meningitis, complicated by thrombosis of the cerebral veins, and infection of the urogenital and the gastrointestinal tracts.
F. necrophorum infection usually responds to treatment with penicillin or metronidazole, but penicillin treatment for persistent pharyngitis appears anecdotally to have a higher relapse rate, although the reasons for that are unclear. This bacterium is also considered the cause of the foot disease thrush in horses.
Although this infection is rare, researchers agree that this diagnosis should be considered in a septicaemic patient with thrombosis in an unusual site, and underlying malignancy should be excluded in cases of confirmed F. necrophorum occurring at sites caudal to the head.

## F. nucleatum
Fusobacterium nucleatum is an oral bacterium, indigenous to the human oral cavity, that plays a role in periodontal disease. This organism is commonly recovered from different monomicrobial and mixed infections in humans and animals. It is a key component of periodontal plaque due to its abundance and its ability to coaggregate with other species in the oral cavity.

## F. polymorphum
Fusobacterium polymorphum is a bacterium that has been isolated from the gingival crevice in humans, and has been implicated in the immunopathology of periodontal disease. It has also been isolated in guinea pigs in research studies.

# Gallery
- Fusobacterium novum after being cultured in a thioglycollate medium for 48 hours. From Public Health Image Library (PHIL). 
- Fusobacterium russii cultured in a thioglycollate medium for 48 hours. From Public Health Image Library (PHIL). 
- Fusobacterium nucleatum cultured on blood agar for 48 hours. From Public Health Image Library (PHIL). 
- Fusobacterium mortiferum after being cultured in a thioglycollate medium for 48 hours. From Public Health Image Library (PHIL). 
- Gram-negative bacterium, Fusobacterium necrogenes cultured in blood agar for 48 hours. From Public Health Image Library (PHIL). 
- Phase-contrast photomicrographic image of Fusobacterium necrophorum. From Public Health Image Library (PHIL). 
- E. coli, F. mortiferum, P. vulgaris, and C. perfringens were grown on a 24hr blood agar culture. From Public Health Image Library (PHIL). 
- This MacConkey plate grew colonies of Escherichia coli, Fusobacterium mortiferum, P. vulgaris, but not C. perfringens. From Public Health Image Library (PHIL). 
- BHI (Brain Heart Infusion) agar culture growing Leptotrichia buccalis bacteria on day 3. From Public Health Image Library (PHIL). 
- Culture dish grew E. coli, F. mortiferum, P. vulgaris, and C. perfringens bacterial colonies. From Public Health Image Library (PHIL). 
- Morphology displayed by four colonies of Fusobacterium fusiforme bacteria that were grown on blood agar medium for 48 hours. From Public Health Image Library (PHIL). 
- Micrograph of an exudate taken from a subdural empyema due to an infection caused by multiple genera of bacteria. From Public Health Image Library (PHIL). 
- Gram-stained photomicrograph depicted numerous Gram-negative Fusobacterium sp. bacteria (956X mag). From Public Health Image Library (PHIL). 
- Acute tropical ulcer caused by fusiform bacilli and spirochetes. From Public Health Image Library (PHIL). 
- Acute tropical ulcer caused by fusiform bacilli and spirochetes. From Public Health Image Library (PHIL). 
- Gram-negative Fusobacterium plauti-vincenti bacteria. From Public Health Image Library (PHIL). 
- Minitek (BD Biosciences) anaerobe identification kit, shows Gram-negative Fusobacterium nucleatum bacteria. From Public Health Image Library (PHIL).