The anaerobic bacterium Cutibacterium acnes has been increasingly linked to the development of degenerative disc disease (DDD), although causality is yet to be conclusively proven. To better study how this organism could contribute to the aetiology of DDD, improved animal models that are more reflective of human disc anatomy, biology and mechanical properties are required. Against this background, our proof-of concept study aimed to be the first demonstration that C. acnes could be safely administered percutaneously into sheep intervertebral discs (IVDs) for in vivo study. Following our protocol, two sheep were successfully injected with a strain of C. acnes (8.3 × 10 6 CFU/disc) previously recovered from a human degenerative disc. No adverse reactions were noted, and at one-month post inoculation all triplicate infected discs in our first animal grew C. acnes, albeit at a reduced load (5.12 × 10 4 to 6.67 × 10 4 CFU/disc). At six months, no growth was detected in discs from our second animal indicating bacterial clearance. This pilot study has demon-strated the feasibility of safe percutaneous injection of C. acnes into sheep IVDs under fluoroscopic guidance. The design of follow-up sheep studies to investigate the potential of C. acnes to drive pathological changes within infected discs should now be pursued.
Bibliographical noteFunding Information:
This research was funded by a grant from the Indiana Orthopaedic Hospital Research Foundation. We thank Molly Miller and Melanie Glover for their assistance in data and information management.
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Cutibacterium acnes; sheep model; spinal intervertebral discs; percutaneous injections; bacterial disci
- Spinal intervertebral discs
- Cutibacterium acnes
- Percutaneous injections
- Bacterial discitis
- Sheep model