Spirochaete

Taxobox
color = lightgrey
name = Spirochaetes

---

image_width = 240px
image_caption = "Treponema pallidum" spirochetes.
domain = Bacteria
phylum = Spirochetes
classis = Spirochetes
ordo = Spirochaetales
ordo_authority = Buchanan 1917
subdivision_ranks = Families
subdivision =
Spirochaetaceae
"Borrelia"
"Brevinema"
"Cristispira"
"Spirochaeta"
"Spironema"
"Treponema"

Brachyspiraceae
"Brachyspira (Serpulina)"
Leptospiraceae
"Leptospira"
"Leptonema"

Spirochaetes is a phylum of distinctive Gram-negative bacteria, which have long, helically coiled cells.cite book | author = Ryan KJ; Ray CG (editors) | title = Sherris Medical Microbiology | edition = 4th ed. | publisher = McGraw Hill | year = 2004 | id = ISBN 0838585299 ] Spirochetes are chemoheterotrophic in nature, with lengths between 5 and 250 µm and diameters around 0.1-0.6 µm.Fact|date=February 2007

Spirochaetes are distinguished from other bacterial phyla by the location of their flagella, sometimes called "axial filaments", which run lengthwise between the cell membrane and outer membrane. These cause a twisting motion which allows the spirochaete to move about. When reproducing, a spirochaete will undergo asexual transverse binary fission.

The spirochaetes are divided into three families (Brachyspiraceae, Leptospiraceae, and Spirochaetaceae), all placed within a single order (Spirochaetales). Disease-causing members of this phylum include the following:

*"Leptospira" species, which causes leptospirosiscite journal |author=McBride A, Athanazio D, Reis M, Ko A |title=Leptospirosis |journal=Curr Opin Infect Dis |volume=18 |issue=5 |pages=376–86 |year=2005 |pmid=16148523 |doi=10.1097/01.qco.0000178824.05715.2c]
*"Borrelia burgdorferi", which causes Lyme disease
*"Borrelia recurrentis", which causes relapsing fevercite journal |author=Schwan T |title=Ticks and Borrelia: model systems for investigating pathogen-arthropod interactions |journal=Infect Agents Dis |volume=5 |issue=3 |pages=167–81 |year=1996 |pmid=8805079]
*"Treponema pallidum", which causes syphilis
*"Treponema pertenue", which causes yaws

Most spirochaetes are free-living and anaerobic, but there are numerous exceptions, including the above.

Cavalier-Smith has postulated that the Spirochaetes belong in a larger clade called Gracilicutes.cite journal | author = Cavalier-Smith, T. | title = Rooting the tree of life by transition analyses | doi = 10.1186/1745-6150-1-19 | journal = Biology Direct | volume = 1 | issue = 19 | year = 2006 | pages = 19 Accessed 10 March 2006]

Historical

Salvarsan, the first antibiotic in medical history, was effective against spirochaetes only and was primarily used to cure syphilis.

It has been suggested by biologist Lynn Margulis that eukaryotic flagella were derived from symbiotic spirochaetes [Margulis, L., M. F. Dolan and R. Guerrero. 2000. The chimeric eukaryote: origin of the nucleus from the karyomastigont in amitochondriate protists. PNAS 97: 6954-6959] , but few biologists accept this, as there is no close structural similarity between the two.

ee also

*Flagellum
*Treponema pallidum
*Lyme disease microbiology
*Borrelia
*Bacteriology
*Prokaryote

References

External links

* [http://web.indstate.edu/thcme/micro/zoo-pos/sld028.htm Indiana State University - Spirochete Pictures]