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)
    • The organism has a safety-pin appearance with stain under microscopy.
• The organism is difficult to demonstrate microbiologically because it does not grow on any standard microbiological laboratory media.
• Culture achieved in the research settings using peripheral blood mononuclear cells cultivated with fetal calf serum after exposure to vancomycin and metronidazole for decontamination.
  • Culture also has been successful on cycloheximide-treated Hep-2 cell monolayers in RPMI 1640 medium, supplemented with fetal calf serum, penicillin, and vancomycin.