26 plus species including:


Borrelia anserina
Borrelia burgdorferi
Borrelia duttonii
Borrelia hermsii
Borrelia parkeri
Borrelia recurrentis
Borrelia turicatae

19 further species are classified by their arthropod vectors.


Gram Stain: Negative.
Morphology: Helical cells with three to ten loose coils.
Size: 0.2-0.5 micrometers by 3.0-20.0 micrometers.
Motility: This species is highly motile with 7-30 periplasmic flagella (axial fibrils, periplasmic fibrils, or endoflagella).
Capsules: No.
Spores: No.
Other: Frequent reversal of direction and translational movement can be seen microscopically. These organisms stain well with Giemsa stain.


In vitro cultivation of Borrelia spp. has been successful in broth medium for only six species; Borrelia hermsii, Borrelia parkeri, Borrelia turicatae and Borrelia duttonii. Method of choice for cultivation and isolation of this organism is through animal inoculation. No solid media for the cultivation of Borrelia has been described.


Microaerophilic (in vitro). Certain species have been documented as fermentative.


Identification of the various species of Borrelia by serological or biochemical reactions has not yet been accomplished.

One species, Borrelia hermsii, has been found to lack catalase and peroxidase.


Pathogens of man, birds, and other animals.


Borreliae are pathogens of man, other mammals, and birds. Infections are acquired from ticks or lice which are parasitized with borreliae. Infections in man produce a severe septicemic illness of which two varieties are recognized: louse-borne (Borrelia recurrentis) and tick-borne relapsing fever (Borrelia burgdorferi). Borrelia burgdorferi is associated with inflammatory arthropathy (Lyme disease) in humans and certain mammals such as dogs, cows and horses.


For culture: Medium A Broth (Borrelia hermsii, Borrelia parkeri, Borrelia turicatae and Borrelia duttonii).
For selective isolation: No medium for selective isolation has been described.
For maintenance: Suspension of the organism in 10% glycerol have been maintained at
-70 degrees C. for years.


Temperature: 35 degrees C.
Time: 6-7 days.
Atmosphere: Microaerophilic (there is evidence that this organism can grow anaerobically).


1. Holt, J.G., et al. 1994. Bergey's Manual of Determinative Bacteriology, 9th ed. Williams & Wilkins, Baltimore, MD.

2. Holt, J.G., et al. 1986. Bergey's Manual of Systemic Bacteriology, Vol. I & II. Williams & Wilkins, Baltimore, MD.

3. The Oxoid Vade-Mecum of Microbiology. 1993. Unipath Ltd., Basingstoke, UK.

4. Internet: Database Search, February, 1998.

5. Murray, P.R., et al. 1995. Manual of Clinical Microbiology, 6th ed. American Society for Microbiology, Washington, D.C.