Spondylodiscitis due to Propionibacterium acnes: report of twenty-nine cases and a review of the literature

Propionibacterium acnes is the most frequent anaerobic pathogen found in spondylodiscitis. A documented case required microbiological proof of P. acnes with clinical and radiological confirmation of inflammation in a localized region of the spine. Microbiological samplings were obtained by surgery or aspiration under radiological control. Twelve males and 17 females (median age, 42 years) with spondylodiscitis due to P. acnes were diagnosed within the last 15 years. Three patients were immunosuppressed. All patients reported back pain as the main symptom, and most were afebrile. Three patients had a peripheral neurological deficit, one a motor deficit, and two a sensory deficit attributable to the infection; and six patients had an epidural abscess. The most frequent risk factor was surgery, which was present in the history 28 of 29 (97%) patients. The mean delay between spinal surgery and onset of disease was 34 months, with a wide range of 0–156 months. Osteosynthesis material was present in twenty-two cases (76%). In 24 (83%) patients, additional surgery, such as débridement or spondylodesis, was performed. Previous osteosynthesis material was removed in 17 of the 22 (77%) patients where it was present. Total cure was reported in all patients, except one, after a mean duration of antibiotic therapy of 10.5 weeks (range, 2–28 weeks). In conclusion, spondylodiscitis due to P. acnes is an acute infection closely related to previous surgery. The most prominent clinical feature is pain, whereas fever is rare, and the prognosis is very good.