Difference between revisions of "Spirochaete"
(leptospirosis and Weil's disease are not synonyms; Weil's disease requires jaundice, which is not found in all leptospirosis patients)
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Revision as of 18:35, 16 October 2007
Treponema pallidum spirochetes.
Spirochetes is a phylum of distinctive Gram-negative bacteria, which have long, helically coiled cells. Spirochetes are chemoheterotrophic in nature, with lengths between 5 and 250 µm and diameters around 0.1-0.6 µm.
Spriochetes are distinguished from other bacterial phyla by the presence of flagella, sometimes called axial filaments, running lengthwise between the cell membrane and outer membrane. These cause a twisting motion which allows the spirochaete to move about.
The spirochaetes are divided into three families, all placed within a single order. Disease-causing members of this phylum include the following:
- Leptospira species, which causes leptospirosis
- Borrelia burgdorferi, which causes Lyme disease
- Borrelia recurrentis, which causes relapsing fever
- Treponema pallidum, which causes syphilis
Most spirochaetes are free-living and anaerobic, but there are numerous exceptions, including the above.
It has been suggested by biologist Lynn Margulis that eukaryotic flagella were derived from symbiotic spirochaetes, but few biologists accept this, as there is no close structural similarity between the two.
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