HELICOBACTER

17 plus species including:

SPECIES

Helicobacter cinaedi
Helicobacter felis
Helicobacter fennelliae
Helicobacter hepaticus
Helicobacter muridarum
Helicobacter mustelae
Helicobacter nemestrinae
Helicobacter pylori

MICROSCOPIC APPEARANCE

Gram Stain: Negative.
Morphology: Helical, curved, or straight rods with rounded ends sometimes forming rare spiral shapes. In older cultures, Helicobacter pylori cells become coccoid, with an associated decrease in ability to subculture. External glycocalyx is produced in vitro in shaken broth cultures.
Size: 2.5-4.0 micrometers by 0.5-5.0 micrometers.
Motility: Rapid and darting motility by means of unipolar, bipolar and/or lateral with terminal bulbs.
Capsules: No.
Spores: No.
Other: Microaerophilic. Helicobacter pylori was originally classified in the genus Campylobacter .

MACROSCOPIC APPEARANCE

Colonies are non-pigmented, translucent, and 1-2 micrometers in diameter.

KEY BIOCHEMICAL REACTIONS

METABOLIC PROPERTIES

Non-glycolytic; microaerophilic; Chemoorganotrophic.

HABITAT

Gastrointestinal mucosa of primates and animals.

PATHOGENICITY

H. pylori appears to be responsible for most cases of chronic active gastritis, and is most common known cause of peptic ulcer disease. Several studies have pointed to an association between H. pylori and carcinoma of the stomach (8)

H. fennelliae and H. cinaedi have been isolated from homosexual men with proctitis, proctocolitis, and enteritis. H. cinaedi has also been isolated from the blood of homosexual men with previously diagnosed acquired immunodeficiency syndrome (AIDS) and from the blood and feces of children and adult females.

RECOMMENDED MEDIA

For culture: Brain Heart Infusion (BHI) Broth, Chocolate Agar, Thioglycollate Broth with Supplements.
For selective isolation: Modified Thayer Martin.
For maintenance: Brucella Broth with 16% Agar for short-term storage or lyophilization, or freezing at -80 degrees C. in liquid nitrogen for long-term preservation.

INCUBATION

Temperature: 30-42 degrees C.
Time: 3-4 days.
Atmosphere: Microaerophilic.

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.

8. Howard, B.J., et al. 1994. Clinical and Pathogenic Microbiology , 2nd ed. Mosby, St. Louis, IL4.


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