GARDNERELLA

SPECIES

Gardnerella vaginalis

MICROSCOPIC APPEARANCE

Gram Stain:	Negative to variable. Not acid-fast.
Morphology:	Usually pleomorphic rods.
Size:	0.5 micrometers in diameter by 1.5-2.5 micrometers in length.
Motility:	Non-motile.
Capsules:	None.
Spores:	None.
Other:	The cell walls are laminated.

MACROSCOPIC APPEARANCE

Small (1mm), beta-hemolytic colonies on media containing human blood. Colonies appear either opaque, dull white, convex, domed, or somewhat conical in shape. G. vaginalis is non-hemolytic on media containing sheep blood.

KEY BIOCHEMICAL REACTIONS

Catalase-negative.
Oxidase-negative.
Most stains are fastidious in growth requirements.
Hippurate hydrolyzed.
Metranidazole-sensitive.
Diffuse beta-hemolysis on media containing human blood.
Sodium-polyanetholsulfate (SPS)-sensitive.

METABOLIC PROPERTIES

Both obligately aerobic, and facultatively anaerobic; Chemoorganotrophic, having fermentative type of metabolism. Produces acid but not gas from glucose and other carbohydrates including maltose and starch.

HABITAT

G. vaginalis is isolated form the human genital/urinary tract and appears to have a worldwide distribution.

PATHOGENICITY

G. vaginalis is believed to be a contributing cause of bacterial "non-specific" vaginitis. It has also occasionally been reported to cause bacteremia in postpartum women and in patients following septic abortion and transurethral resection of the prostate.

RECOMMENDED MEDIA

For culture:	Chocolate Agar, Columbia Blood Agar, V Agar.
For selective isolation:	V Agar with CNA.
For maintenance:	Brucella Broth with 20% Glycerol or Skim Milk for long-term storage at -70 degrees C.

INCUBATION

Temperature:	35-37 degrees C.
Time:	48 hours.
Atmosphere:	Aerobic with increased CO ₂ (5-10%).

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.

IFU-10445[A]