Brachyspiraceae
Leptospiraceae
Spirochaetaceae The spirochaetes are a phylum of distinctive bacteria, which have long, helically coiled cells. They are distinguished by the presence of flagella running lengthwise between the cell membrane and cell wall, called axial filaments. These cause a twisting motion which allows the spirochaete to move about. Most spirochaetes are free-living and anaerobic, but there are numerous exceptions.

It has been suggested by 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.

The spirochaetes are divided into three families, all placed within a single order. Important members of this phylum include

• Leptospira species, which causes leptospirosis,
• Borrelia bergdorferi , which causes Lyme disease, and
• Treponema pallidum, which causes syphilis.

External links

• Cystic Forms of Spirochetes: Complete Bibliography and Pictures