A case of pyogenic spondylitis caused by Paludibacterium purpuratum

Abstract Paludibacterium purpuratum was first reported as a Gram stain-negative, curved, rod-shaped bacterium isolated from a wetland soil in 2016. We report the first case in the world, to our knowledge, of pyogenic spondylitis caused by P. purpuratum. The patient, a 78-year-old man, came to our hospital complaining chiefly of fever and pain in the left knee. He did not complain of low back pain at the time of examination, although increased low back pain was observed for the first time after admission. Magnetic resonance imaging of the lumbar spine and percutaneous needle biopsy at the L2/L3 disc level were performed, and pyogenic spondylitis was diagnosed. A curved, Gram stain-negative rod was detected in the blood culture obtained at admission that was identified as P. purpuratum by 16S rDNA gene analysis.