Risk factors and outcomes of Cutibacterium acnes postoperative central nervous system infection: a case-control study

Abstract Objective Cutibacterium acnes has emerged as a significant cause of postoperative central nervous system infections (PCNSI). We sought to determine risk factors and outcomes associated with C. acnes PCNSI. Methods This was a single-center 1:1 case-control study of patients with monobacterial C. acnes-associated PCNSI (cases) and unmatched controls with PCNSI caused by aerobic organisms. Patient and procedure-related characteristics were compared between groups. The main outcome was cure at 90 days after diagnosis. Mortality and neurologic disability were secondary outcomes. Results We identified 13 patients with C. acnes PCNSI and 13 controls. All patients had postoperative intracranial abscess. Onset of infection was significantly later for cases versus controls (median and range, 22 [19-116] days and 15 [1-27] days, respectively; P =0.002). Prolonged anaerobic incubation was required for C. acnes isolation (median, 8 days versus 2 days for aerobic pathogens; P Conclusions C. acnes PCNSI presents later than infection with aerobic bacteria, but is associated with similar risk factors and clinical outcomes. These results underscore the importance of prolonged anaerobic incubation to optimize the recovery of C. acnes in the laboratory.