Klebsiella granulomatis (Granuloma inguinale, Donovanosis)

MICROBIOLOGY

• Klebsiella granulomatis (formerly known as Calymmatobacterium granulomatis) is a member of the family Enterobacteriaceae; reclassification is based upon nucleotide relatedness to other Klebsiella spp. especially to K. rhinoscleromatis, another tropical infection (nasal).
  • Pleomorphic, intracellular (macrophages > neutrophils), Gram-negative bacillus surrounded by a well-defined bipolar staining capsule (seen with Wright, Giemsa or Leishman stain) giving the organism a safety-pin appearance.
• Organism is difficult to demonstrate microbiologically because it does not grow on any standard microbiological laboratory media.
• Culture has been achieved in the research setting using peripheral blood mononuclear cells cultivated with fetal calf serum after exposure to vancomycin and metronidazole for decontamination; culture also has been successful on cyclohexamide-treated Hep-2 cell monolayers in RPMI 1640 medium, supplemented with fetal calf serum, penicillin, and vancomycin.