Propionibacterium acnes contamination in lumbar disc surgery.

Previous studies have shown that Propionibacterium acnes may be responsible for low-grade infection of the intervertebral discs of patients with severe sciatica. The aim of this study was to prospectively investigate the presence of bacteria in disc fragment samples obtained during surgery for lumbar disc herniation. P. acnes was cultured from disc fragments in two (3.7%) of 54 patients studied. In addition, control cultures taken from ligamentum flavum and muscle from these two patients were also positive for P. acnes. Similar control cultures were positive for P. acnes from a further ten (18.5%) patients. Four air samples taken during surgery all contained P. acnes; the organism was also found from three of 54 laminar flow control cultures. Sample contamination appears the most likely cause for the presence of P. acnes in the lumbar disc fragment cultures.