HAFNIA

SPECIES

Hafnia alvei

MICROSCOPIC APPEARANCE

Gram Stain: Negative.
Morphology: Straight rods.
Size: 1.0 micrometer by 2.0-5.0 micrometers.
Motility: Motility occurs at 30 degrees C. by peritrichous flagella.
Capsules: No.
Spores: No.

MACROSCOPIC APPEARANCE

Colonies are non-lactose-fermenters and may resemble Salmonellae. Most strains are translucent or colorless; rare strains may produce red or pink colonies on media containing sucrose.

KEY BIOCHEMICAL REACTIONS

METABOLIC PROPERTIES

Facultatively Anaerobic. Chemoorganotrophic; utilizing both fermentative and respiratory type metabolisms. Utilizes citrate, acetate and malonate as sole source of carbon. Glucose is fermented with the production of acid and gas. Acid is not produced from sorbitol, raffinose, melibiose, adonitol, and myo -inositol.

HABITAT

H. alvei occurs not only in man and animals and birds, but also in natural environments such as soil, sewage and water. H. alvei is found in clinical specimens, especially from feces in healthy humans, occasionally blood, sputum, urine, and wounds, abscesses, the throat, abdominal cavity and autopsies.

PATHOGENICITY

H. alvei seem to be opportunistic pathogens which produce infections in patients with underlying illness or predisposing factors. H. alvei has been reported as a possible causative agent of intestinal disorders. However, no conclusive evidence has been obtained regarding its enteropathogenicity.

RECOMMENDED MEDIA

For culture: Tryptic Soy Agar, or Blood Agar 5%.
For selective isolation: EMB, MacConkey Agar, Hektoen Enteric Agar, SS or XLD Agar.
For maintenance: CTA at room temperature for up to 1 year. Lyophilization is required for long-term storage.

INCUBATION

Temperature: 30-37 degrees C.
Time: 16-8 hours.
Atmosphere: Aerobic.

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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