Figure 1.

P. acnes identified and isolated from a nonpyogenic intervertebral disc. (a)–(c) A 68-year male patient (patient's ID: number 9) underwent discectomy due to severe low back pain and sciatica. The disc harvested from the patient at level of L4~5 was proved to be P. acnes-positive using anaerobic culture and 16S rDNA PCR. The signs of discitis, such as osteolytic changes of endplates or vertebrae, pyogenic changes of disc, and septic changes of vertebral surrounding soft tissues, were not seen in T1WI (a), T2WI (b), and STIR (c) of MRI (marked with white blank arrows). (d) Rod-shaped, Gram-positive bacterium was isolated and purified from the P. acnes-positive disc (marked with black arrows) and the purified bacterium was P. acnes.