35 plus species including:
Bifidobacterium dentium (formerly B. eriksonii )
|Gram Stains:||Gram-positive. The cells often stain irregularly. Non-acid-fast.|
|Morphology:||Pleomorphic, coryneform rods. They usually appear clubbed or branching and may display bifurcated ends. Some species occasionally exhibit swollen coccoid forms.|
|Size:||0.5-1.3 by 1.5-8.0 micrometers.|
|Motility:||They are non-motile, with some species being regularly motile.|
|Other:||Bifidobacterium spp. are sometimes arranged in pairs, "V" arrangements, in chains, and in palisades of parallel cells or rosettes.|
Bifidobacterium dentium produces a white, convex, shiny colony with irregular edges on solid media. Growth in broth is diffuse.
Anaerobic. Acetic and lactic acid are produced from glucose.
KEY BIOCHEMICAL REACTIONS
- Usually catalase-negative.
- Fermentative: No gas production from glucose.
Found in the mouth and intestine of man, other warm-blooded animals and insects, also found in sewage and clinical specimens.
These organisms are usually considered non-pathogenic. However, they have been implicated in human infections including abscesses. B. dentium appears to have the most possible pathogenic potentiality as a result of isolation from human dental plaque and caries. (2)
|For culture:||Tomato Juice Agar, V9 Agar, SabDex, MRS Agar or MRS Broth.|
|For selective isolation:||None recommended.|
|For maintenance:||SabDex, V9 Agar, or Tomato Juice Agar.|
|Temperature:||39-40 degrees C.|
|Atmosphere:||Anaerobic. Some Bifidobacterium spp. may grow aerobically with an enriched atmosphere containing 10% CO 2 .|
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.