Fusobacterium

Fusobacterium is a genus of filamentous, anaerobic, Gram-negative bacteria, similar to Bacteroides.^[1] Fusobacterium contribute to several human diseases, including periodontal diseases, Lemierre's syndrome, and topical 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.^[2]

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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^[2] and 21% of all recurring sore throats,^[3][4] 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,^[5] and infection of the urogenital and the gastrointestinal tracts.^[6]

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.^[7]

F. necrophorum is also a cause for lameness in sheep. Its infection is commonly called scald. It can last for several years on land used by either sheep or cattle and is found on most land of this type throughout the world. Due to it's survival length in these areas it is unrealistic to try to remove it. Sheep most often get scald due to breakage or weekness of the skin suronding the hoof. This can occur due to strong footbaths, sandy soils, mild frost byte or prolongened waterlogging of a field which results in denaturing of the skin between the cleats.^[8]

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.^[9]

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.^[10]

References

1. ^ Madigan M; Martinko J (editors). (2005). Brock Biology of Microorganisms, 11th ed., Prentice Hall. ISBN 0-13-144329-1. 
2. ^ ^{a b} Aliyu SH, Marriott RK, Curran MD, et al. (2004). "Real-time PCR investigation into the importance of Fusobacterium necrophorum as a cause of acute pharyngitis in general practice". J Med Microbiol 53: 1029–35. doi:10.1099/jmm.0.45648-0.
3. ^ Batty A, Wren MW. (2005). "Prevalence of Fusobacterium necrophorum and other upper respiratory tract pathogens isolated from throat swabs". Br J Biomed Sci 62 (2): 66–70. PMID 15997879.
4. ^ Batty A, Wren MW, Gal M. (2004). "Fusobacterium necrophorum as the cause of recurrent sore throat: comparison of isolates from persistent sore throat syndrome and Lemierre's disease". J Infect 51 (4): 299–306. doi:10.1016/j.jinf.2004.09.013. PMID 16051369.
5. ^ Larsen PD, Chartrand SA, Adickes M. (1997). "Fusobacterium necrophorum meningitis associated with cerebral vessel thrombosis.". Pediatr Infect Dis J 16 (3): 330–331. PMID 9076827.
6. ^ Hagelskjaer Kristensen L, Prag J. (200). "Human necrobacillosis, with emphasis on Lemierre's syndrome.". Clin Infect Dis 31 (2): 524–532. PMID 10987717.
7. ^ Redford ML, Ellis R, Rees CJ. (2005). "Fusobacterium necrophorum infection associated with portal vein thrombosis.". J Med Microbiol 54 (5): 993–995. doi:10.1099/jmm.0.46080-0. PMID 10987717.
8. ^ http://www.defra.gov.uk/animalh/welfare/pdf/sheeplameness.pdf
9. ^ Kapatral V, et al. (2002). "Genome sequence and analysis of the oral bacterium 'Fusobacterium nucleatum' strain ATCC 25586.". J Bacteriol 184 (7): 2005–2018. PMID 11889109.
10. ^ Hawley CE, Falker Jr. WA. (1977). "Anticomplementary activity of 'Fusobacterium polymorphum' in normal and C4-deficient sources of guinea pig complement.". Infect Immun 18 (1): 124–129.