PROVIDENCIA

6 plus species including:

SPECIES

MICROSCOPIC APPEARANCE

Gram Stain: Gram-negative.
Morphology: Straight rods.
Size: 0.6-0.8 micrometers by 1.5-2.5 micrometers.
Motility: Motile by peritrichous flagella.
Capsules: None.
Spores: None.

MACROSCOPIC APPEARANCE

Relatively large, dull gray colonies; non-swarming. Providencia spp. usually appear colorless on enteric agars such as Eosin Methylene Blue (EMB) Agar, Hektoen Enteric (HE) Agar, and Salmonella Shigella (SS) Agar.

KEY BIOCHEMICAL REACTIONS

METABOLIC PROPERTIES

Facultatively anaerobic. Chemoorganotrophic, having both a fermentative and respiratory type metabolism.

HABITAT

The most common site of P . stuartii and P . rettgeri infections is the urinary tract of the catheterized or compromised patient. Extraintestinal tracts (stool samples) of human beings and other animals, in particular poultry, are also common sites of Providencia spp.

PATHOGENICITY

Strains of P . stuartii and P . rettgeri may produce wound and burn infections. The rise in medical importance of these organisms is associated with its' tendency to cause nosocomial infections and with their marked resistance to numerous antibiotics. (2) This species is also associated with diarrhea, urinary tract infections, wound and burn infections, bacteremias, and poultry diseases.

RECOMMENDED MEDIA

For culture: Tryptic Soy Agar or Blood Agar 5%.
For selective isolation: Simmons Citrate Agar, MacConkey Agar, Tergitol Agar, or HardyCHROMâ„¢ UTI.
For maintenance: Tryptic Soy Agar or Blood Agar 5%. Brucella with 20% Glycerol or Skim Milk for long-term storage at -70 degrees C. Lyophilization may be used for preservation.

INCUBATION

Temperature: 37 degrees C.
Time: 16-24 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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