SARCINA

SPECIES

MICROSCOPIC APPEARANCE

Gram Stain: Gram-positive.
Morphology: Spherical, appearing in cuboidal packets of eight or more. Division occurs in three perpendicular planes. Some cells occur singly, in pairs, or tetrads.
Size: 1.8 to 3.0 micrometers.
Motility: Non-motile.
Capsules: None.
Spores: Reported, but not usually seen.

MACROSCOPIC APPEARANCE

Organisms are not pigmented, but do appear star shaped with rugged edges. Cells are usually flattened in areas of contact with adjacent cells.

BIOCHEMICAL REACTIONS

METABOLIC PROPERTIES

Anaerobic. Chemoorganotrophic, metabolism is fermentative with carbohydrates as substrates producing H 2 , CO 2 , and acetic acid.

HABITAT

S. ventriculi has been isolated from soil, mud, contents of diseased human stomach, rabbit and guinea pig stomach contents, elephant dung, human feces, and the surface of cereal seeds. S. maxima has been isolated from the hull or outer coat of cereal grains, such as wheat, oat, rice, and rye. It was also isolated from fresh wheat bran, horse manure and soil.

PATHOGENICITY

Growth of S. ventriculi takes place in the human stomach as a result of the development of certain pathological conditions (pyloric ulceration or stenosis) that retard the flow of food to the intestine. Often resulting in diseased stomachs and colons in human beings.

RECOMMENDED MEDIA

For culture: Nutrient Agar.
For selective isolation: Malt Extract Broth or Enrichment Media.
For maintenance: Agar Medium for short-term maintenance and liquid nitrogen for long-term preservation.

INCUBATION

Temperature: 30-37 degrees C.
Time: 16-18 hours.
Atmosphere: Anaerobic.
pH: 2.0-3.0.

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.


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