Spirochete

Spirochete

Spirochaetes
Spirochaetes.  Numbered ticks are 11 µm apart.  Gram-stained.
Treponema pallidum spirochaetes.
Scientific classification
Domain: Bacteria
Phylum: Spirochaetae Cavalier-Smith 2002
Class: Spirochaetes Cavalier-Smith 2002
Order: Spirochaetales Buchanan 1917
Families & Genera
  • ?Exilispira Imachi et al. 2008
  • Brevinemataceae Paster 2012
    • Brevinema Defosse et al. 1995
  • Brachyspiraceae Paster 2012
    • Brachyspira Hovind-Hougen et al. 1983
  • Leptospiraceae Hovind-Hougen 1979 emend. Levett et al. 2005
    • Leptonema Hovind-Hougen 1983
    • Leptospira Noguchi 1917 emend. Faine and Stallman 1982
    • Turneriella Levett et al. 2005
  • Spirochaetaceae Swellengrebel 1907
    • Borrelia Swellengrebel 1907
    • ClevelandinaBermudes et al. 1988
    • CristispiraGross 1910
    • Diplocalyx(ex Gharagozlou 1968) Bermudes et al. 1988
    • Hollandina(ex To et al. 1978) Bermudes et al. 1988
    • Pillotina(ex Hollande and Gharagozlou 1967) Bermudes et al. 1988
    • Sphaerochaeta Ritalahti et al. 2012
    • Spirochaeta Spirochaeta Ehrenberg 1835 emend. Pikuta et al. 2009
    • SpironemaTurk et al. 1999
    • Treponema Schaudinn 1905

Spirochaetes (also spelled spirochetes) belong to a phylum of distinctive diderm (double-membrane) bacteria, most of which have long, helically coiled (spiral-shaped) cells.[1] Spirochaetes are chemoheterotrophic in nature, with lengths between 5 and 250 µm and diameters around 0.1–0.6 µm.

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

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

Classification

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:

Cavalier-Smith has postulated that the Spirochaetes belong in a larger clade called Gracilicutes.[5]

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) [6] and National Center for Biotechnology Information (NCBI)[7] and the phylogeny is based on 16S rRNA-based LTP release 111 by 'The All-Species Living Tree' Project [8]


Leptospiraceae

Turneriella parva (Hovind-Hougen et al. 1982) Levett et al. 2005




Leptonema illini Hovind-Hougen 1983



Leptospira Noguchi 1917 emend. Faine and Stallman 1982







Brevinema andersonii Defosse et al. 1995



Brachyspira Hovind-Hougen et al. 1982





Exilispira thermophila Imachi et al. 2008


Spirochaetaceae

?Clevelandina reticulitermitidisBermudes et al. 1988



?Cristispira pectinisGross 1910



?Diplocalyx calotermitidis(ex Gharagozlou 1968) Bermudes et al. 1988



?Hollandina pterotermitidis(ex To et al. 1978) Bermudes et al. 1988



?Pillotina calotermitidis(ex Hollande and Gharagozlou 1967) Bermudes et al. 1988



Spironema culicisTurk et al. 1999



Spirochaeta [paraphyletic incl. Borrelia, Sphaerochaeta and Treponema]






Notes:
♦ Type strain lost or not available
♪ Prokaryotes where no pure (axenic) cultures are isolated or available, i. e. not cultivated or can not be sustained in culture for more than a few serial passages
♠ Strains found at the National Center for Biotechnology Information (NCBI) but not listed in the List of Prokaryotic names with Standing in Nomenclature (LSPN)

Historical

Salvarsan, the first partially organic antimicrobial drug in medical history, was effective against spirochaetes only and was primarily used to cure syphilis.

See also

References

External links

  • Introduction to the Spirochetes University of California Museum of Paleontology (UCMP)