Klebsiella granulomatis

Klebsiella granulomatis is a Gram-negative, rod-shaped bacterium of the genus Klebsiella known to cause the sexually transmitted infection granuloma inguinale (or donovanosis). It was formerly called Calymmatobacterium granulomatis.

It is a non-motile aerobic bacillus with a non-sporulated capsule measuring 0.5 to 2.0 μm. It is biochemically characterised by being as catalase-positive, phenylalanine deaminase-negative, citrate test-positive, and urease-positive. Among its virulence factors are its capsule, endotoxins, siderophores, antimicrobial resistance and antigenic phase variation.