TREPONEMA

6 plus species including:

SPECIES

MICROSCOPIC APPEARANCE

Gram Stain: Gram-negative, difficult to stain.
Morphology: Helical rods. Cells have tight, regular, and irregular spirals.
Size: Most species are 0.1-0.4 micrometers by 5.0-20.0 micrometers. T . pallidum is about 0.18 micrometers in diameter and 6-20 micrometers in length.
Motility: Motile with rotational movement by periplasmic flagella. Treponema spp. may have translational movement in liquid media.
Capsules: Intracytoplasmic tubules are present.
Spores: None.

MACROSCOPIC APPEARANCE

White colonies appear after incubation for those species that can be cultivated.

KEY BIOCHEMICAL REACTIONS

METABOLIC PROPERTIES

Strictly anaerobic or microaerophilic. Chemoorganotrophic, utilizing a variety of carbohydrates and amino acids as carbon and energy sources.

HABITAT

The oral cavity, intestinal tract, rumen, and genital areas of humans and animals. Treponema species are distributed worldwide and remain a major public heath problem.

PATHOGENICITY

Some species are pathogenic and parasitic for humans and other animals, generally resulting in local lesions in tissue, syphilis, yaws, or pinta.

Only one pathogenic member of the anaerobic Treponema has been identified. T. hyodysenteriae is the etiologic agent of swine dysentery. Many of the other Treponema have been found in certain human skin ulcers, periodontal disease, and diarrheal illness; however, their role as a causative agents of these diseases remains undefined. (8)

The remaining species of Treponema include T. pallidum , T. carateum , and T. paraluiscuniculi . The last organism is responsible for diseases in rabbits. T. pallidum , the etiological agent of venereal and congenital syphilis as well as yaws, and T. carateum , the etiological agent of pinta, are human pathogens.

RECOMMENDED MEDIA

For culture: 3 subspecies ( Treponema pallidum , Treponema carateum , and Treponema paraluiscuniculi have not been cultivated successfully in media or tissue culture). All other species can be isolated from mixed cultures by the membrane technique on serum or rumen agar and then subcultured in pre-reduced broth. (2)
For maintenance: 10% Glycerol or DMSO can be added to broth culture for storage at -70 degrees C. Lyophilization in Skim Milk is required for long-term preservation.

INCUBATION

Temperature: 37 degrees C.
Time: 1-2 weeks.
Atmosphere: Anaerobic or microaerophilic.

REFERENCES

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

5. Internet: www.hardlink.com /Bacterial Database Search, February, 1998.

6. Hensyl, B.R., et al. 1990. Stedman's Medical Dictionary , 25th ed. Williams & Wilkins, Baltimore, MD.

7. Koneman, et al. 1997. Color Atlas and Textbook of Diagnostic Microbiology , 5th ed. Lippincott, Philadelphia, PA.

8. Howard, B.J., et al. 1994. Clinical and Pathogenic Microbiology , 2nd ed. Mosby, St. Louis, IL.


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