ALCALIGENES

19 plus species including:

SPECIES

Alcaligenes eutrophus
Alcaligenes faecalis
Alcaligenes flatus
Alcaligenes paradoxus
Alcaligenes piechaudii
Alcaligenes xylosoxidans

MICROSCOPIC APPEARANCE

Gram Stain: Negative.
Morphology: Coccal or cocci.
Size: 0.5 - 1.0 micrometers by 0.5 - 2.6 micrometers.
Motility: Motile with peritrichous flagella.
Capsules: No.
Spores: No.
Other: Obligate aerobes.

MACROSCOPIC APPEARANCE

Colonies appear non-pigmented and similar in size to Acinetobacter spp.

METABOLIC PROPERTIES

Chemoorganoheterotrophic, some strains chemolithotrophic; respiratory; acetate, lactate, amino acids, etc. used as carbon sources.

KEY BIOCHEMICAL REACTIONS

HABITAT

Widely distributed in soil and water.

PATHOGENICITY

Alcaligenes faecalis is the most frequently isolated species of Alcaligenes . This organism has been recovered from blood, sputum, feces, purulent ear discharges, spinal fluid, wounds and urine specimens. It has been associated with nosocomially acquired septicemia and pyrexic reactions without septicemia. Other strains have been associated with rare cases of meningitis cervical lymphadenopathy, pneumonia, and ventriculitis following neurosurgical operations. Although meningitis due to this organism is rare, such infections are associated with a high mortality rate, frequent hydrocephalus, and subsequent neurologic sequelae; in utero transmission leading to fatal meningitis is also possible.

RECOMMENDED MEDIA

For culture: Blood Agar 5%, Nutrient Broth, TSB Broth, or Brain Heart Infusion (BHI) Broth.
For selective isolation: MacConkey Agar or HE Agar.
For maintenance: Blood Agar 5%.

INCUBATION

Temperature: 20 degrees C. (foodstuffs) or 35 degrees C. (clinical material).
Time: 24 - 48 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 , Volumes I & II. Williams & Wilkins, Baltimore, MD6.

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.


022699na