BARTONELLA

13 plus species including:

SPECIES

Bartonella bacilliformis Bartonella elizabethae (formally known as Rochalimaea elizabethae )
Bartonella henselae (formally known as Rochalimaea henselae )
Bartonella quintana (formally known as Rochalimaea quintana )
Bartonella vinsonii

Recent research based on DNA amplification has reclassified the genus Rochalimaea to the genus Bartonella .

MICROSCOPIC APPEARANCE

Gram Stain: Negative. The organism is not acid fast. When in stained blood films Bartonella spp. are typically rounded or ellipsoidal forms or as slender, straight, curved, or bent rods occurring singly or in groups when in stained blood films.
Morphology: Polymorphic, bacilliform bodies are the most typical.
Size: 0.25-0.5 micrometers by 1.0-3.0 micrometers. Rounded organisms measure approximately 0.75 micrometers in diameter.
Motility: Motile in culture. In culture the organism has unipolar flagella.
Capsules: No.
Spores: No.
Other: They characteristically occur in chains of several segmenting organisms, sometimes swollen at one or both ends and frequently beaded. Bartonella spp. is best seen in blood or tissue stained with Giemsa, stain poorly or not at all with many aniline dyes.

MACROSCOPIC APPEARANCE

In semi-solid media the organism appears as white puff-balls, just below the surface of the media. They measure from 1 to 5mm in diameter after 1-2 weeks of incubation.

METABOLIC PROPERTIES

Aerobic. Produces no acid and no gas from amygdalin, arabinose, dextrin, dulcitol, fructose, galactose, glucose, inulin, lactose, maltose, mannitol, mannose, raffinose, rhamnose, salicin, sucrose, or xylose.

KEY BIOCHEMICAL REACTIONS

HABITAT

Human bartonellosis occurs only at elevations of 500 to 3,000m in the Andes mountains in regions of South and Central America. The insect vector, the sandfly of the genus Phlebotomus, transmits the disease to humans during nocturnal feeding; the insects survive only in the limited ecosphere in which the disease is found.

PATHOGENICITY

Bartonella infection can manifest as diphasic illness. Oroya fever, the initial phase of the infection, appears as a severe, febrile, hemolytic anemia. It may be complicated by superinfection with Salmonella , and if it is untreated the mortality is 40% to 90%. B. bacilliformis may infect more than 90% of the red blood cells during this stage.

The second stage of infection is verruga peruana, or Peruvian warts. During this period, Bartonellaceae disappear from the blood and multiple disfiguring cranberry-like skin eruptions develop. These eruptions are characterized by angiogenesis or vascular endothelial cell proliferation. (6)

Other diseases have been linked to various species of Bartonella . These include: bacillary angiomatosis ( Bartonella henselae ) or Carrion's Disease, endocarditis in dogs and humans ( Bartonella elizabethae ); and trench fever ( Bartonella quintana ).

RECOMMENDED MEDIA

For culture: Semi-solid media such as BHIA with 0.4% agar and 5% human, rabbit or horse blood. Organism does not grow well in broth, therefore, no broth formulations are recommended.
For selective isolation: None recommended.
For maintenance: As for culture; Bartonella spp. have remained viable at -70 degrees C. for up to five years.

INCUBATION

Temperature: 25 degrees C.
Time: Up to four (4) weeks - subculture to semi-solid blood or semi-solid serum agar and incubate for 10 days.
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. Howard, B.J., et al. 1994. Clinical and Pathogenic Microbiology , 2nd ed. Mosby, St. Louis, IL.


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