Spirochaete

Spirochaetes (or Spirochetes) are the phylum Spirochaetae. These are double-membrane bacteria with long, helically coiled (spiral-shaped) cells.

Leptospira spirochaetes under scanning electron microscope

Spirochaetes are bacteria. They have flagella, which run lengthwise between the cell wall and outer membrane. The flagella cause a twisting motion which moves the spirochaete about.

Most spirochaetes are free-living and anaerobic, but there are many parasitic species.

Classification

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

• Leptospira species, some of which which cause leptospirosis^[1]
• Borrelia species, some of which cause Lyme disease
  • Borrelia recurrentis, which causes relapsing fever.^[2]
• Treponema pallidum subspecies which cause syphilis and yaws.
• Brachyspira species, which cause intestinal spirochaetosis.^[3]

References

1. McBride A.; et al. (2005). "Leptospirosis". Current Opinion in Infectious Diseases. 18 (5): 376–86. doi:10.1097/01.qco.0000178824.05715.2c. PMID 16148523. S2CID 220576544.
2. Schwan T (1996). "Ticks and Borrelia: model systems for investigating pathogen-arthropod interactions". Infect Agents Dis. 5 (3): 167–81. PMID 8805079.
3. Amat Villegas I.; et al. (2004). "Colonic spirochetes: an infrequent cause of adult diarrhea". Gastroenterol Hepatol (in Spanish). 27 (1): 21–3. doi:10.1016/s0210-5705(03)70440-3. PMID 14718105.

Other websites

• Introduction to the Spirochetes. UCMP.