Calymmatobacterium - Bacteria

Calymmatobacterium

Calymmatobacterium (Donovania) granulomatis is the causative agentofgranulomainguinale, agranulomatousdisease, which involves the genital and inguinal part of the infected host. C. granulomatis was first discovered by Donovan in 1905.He demonstrated the characteristic intracellular bodies in stained smears of pus from ulcer of a patient suffering from donovanosis, a sexually transmitted disease first described in India by Mac Leod. C. granulomatis is a small Gram-negative coccobacillus, which measures 1–2 3 0.5–1.5 mm in size. The bacterium often shows bipolar staining, giving rise to safety-pin appearance. It is a capsulated bacterium but is nonmotile, nonsporing, and non–acid fast. It can be grown with difficulty on egg yolk medium or modified Levinthal agar. The bacterium grows readily in the yolk sac of embryo-nated egg.

    C. granulomatis causes granuloma inguinale, which has anincubation period of few weeks to months. The condition manifests as the presence of subcutaneous nodules on geni-tal organs or in inguinal area. Subsequently, these nodules suppurate and break down, leading to formation of painless granulomatous lesions.

      Granuloma inguinale is seen in Caribbean islands and New Guinea. The condition is a sexually transmitted disease, transmitted through sexual contact. These organisms are found in the cytoplasm of histiocytes, polymorphonuclear leukocytes or remain free outside the cell. These are called Donovan bodies. About 1–25 bacteria can be found within amononuclear phagocyte.

    Laboratory diagnosis of the condition is made by demon-strating these characteristic Donovan bodies within mono-nuclear phagocytes. Specimen is collected by scraping the border of the ulcerative lesion and making a smear on a glass slide. The smears are stained with Giemsa or Wright stains. In the stained smear, the body of the bacillus is stained blue and the capsule is stained pink.

      Tetracyclines, erythromycin, and trimethoprim–sulfamethoxa-zole are effective for treatment of the condition.