Gram-negative pleomorphic rods, 0.5-1.5 micrometers by 1.0-2.0 micrometers in length with rounded ends. They occur singly or in clusters and are non-motile. The cells exhibit single or bipolar condensation of chromatin; "safety pin" forms. Capsules are present.
This organism is extremely fastidious and does not grow on solid medium. In vitro cultivation has been successful only on semi-solid media, therefore no description of colony morphology exists.
KEY BIOCHEMICAL REACTIONS
This organism is usually identified by direct microscopic examination of diseased tissue smears stained by the Wright's method. The organism usually occurs within the cytoplasm of large mononuclear monocytes as blue to purple pleomorphic rods surrounded by pink capsules referred to as "Donovan bodies." The organism may occasionally be observed in free extracellular spaces. The single or bipolar condensation of chromatin gives rise to characteristic "safety pin" forms.
Specific intracellular pathogen of man.
Donovanosis is seen throughout the world and is endemic in many areas including the United States. Symptoms of this venereally transmitted disease include subcutaneous lesions that enlarge and evolve to form beefy, granulomatous painless lesions that bleed easily. Patients often have inguinal lymphadenopathy. The etiological agent of this disease is Calymmatobacterium granulomatis and is seen primarily in dark skinned races. This disease occurs primarily in regions where the climate is warm and humid for several months of the year. Donovanosis is recognized as an infection resulting from intimate contamination and poor hygiene.
|For culture:||Dienst's Egg Yolk Medium (2)|
|For selective isolation:||None described.|
|For maintenance:||Dienst's Egg Yolk Medium|
|Temperature:||35 degrees C.|
|Atmosphere:||Aerobic with reduced oxygen.|
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.