Robert P Howlin1, Christopher Winnard2, Elizabeth M Angus3, Connor J Frapwell2, Jeremy S Webb4, John J Cooper5, Sean S Aiken5, Julie Y Bishop6, Paul Stoodley7. 1. Southampton National Institute for Health Research Respiratory Biomedical Research Unit, University of Southampton and University Hospital Southampton National Health Service Foundation Trust, Southampton General Hospital, Southampton, UK; Centre for Biological Sciences, Faculty of Natural and Environmental Sciences and Institute for Life Sciences, University of Southampton, Southampton, UK. Electronic address: rph@soton.ac.uk. 2. Centre for Biological Sciences, Faculty of Natural and Environmental Sciences and Institute for Life Sciences, University of Southampton, Southampton, UK. 3. Biomedical Imaging Unit, Southampton General Hospital, Southampton, UK. 4. Southampton National Institute for Health Research Respiratory Biomedical Research Unit, University of Southampton and University Hospital Southampton National Health Service Foundation Trust, Southampton General Hospital, Southampton, UK; Centre for Biological Sciences, Faculty of Natural and Environmental Sciences and Institute for Life Sciences, University of Southampton, Southampton, UK. 5. Biocomposites Ltd, Keele, UK. 6. Department of Orthopaedics, Ohio State University Sports Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA. 7. Southampton National Institute for Health Research Respiratory Biomedical Research Unit, University of Southampton and University Hospital Southampton National Health Service Foundation Trust, Southampton General Hospital, Southampton, UK; National Centre for Advanced Tribology, Faculty of Engineering and Institute for Life Sciences, University of Southampton, Southampton, UK; Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, USA; Department of Orthopaedics, The Ohio State University, Columbus, OH, USA.
Abstract
BACKGROUND: The role of Propionibacterium acnes in shoulder arthroplasty and broadly in orthopedic prosthetic infections has historically been underestimated, with biofilm formation identified as a key virulence factor attributed to invasive isolates. With an often indolent clinical course, P acnes infection can be difficult to detect and treat. This study investigates absorbable cements loaded with a broad-spectrum antibiotic combination as an effective preventive strategy to combat P acnes biofilms. METHODS: P acnes biofilm formation on an unloaded synthetic calcium sulfate (CaSO4) bone void filler cement bead was evaluated by scanning electron microscopy over a period of 14 days. Beads loaded with tobramycin alone or vancomycin alone (as comparative controls) and beads loaded with a vancomycin-tobramycin dual treatment were assessed for their ability to eradicate planktonic P acnes, prevent biofilm formation, and eradicate preformed biofilms using a combination of viable-cell counts, confocal microscopy, and scanning electron microscopy. RESULTS: P acnes surface colonization and biofilm formation on unloaded CaSO4 beads was slow. Beads loaded with antibiotics were able to kill planktonic cultures of 106 colony-forming units/mL, prevent bacterial colonization, and significantly reduce biofilm formation over periods of weeks. Complete eradication of established biofilms was achieved with a contact time of 1 week. CONCLUSIONS: This study demonstrates that antibiotic-loaded CaSO4 beads may represent an effective antibacterial and antibiofilm strategy to combat prosthetic infections in which P acnes is involved.
BACKGROUND: The role of Propionibacterium acnes in shoulder arthroplasty and broadly in orthopedic prosthetic infections has historically been underestimated, with biofilm formation identified as a key virulence factor attributed to invasive isolates. With an often indolent clinical course, P acnes infection can be difficult to detect and treat. This study investigates absorbable cements loaded with a broad-spectrum antibiotic combination as an effective preventive strategy to combat P acnes biofilms. METHODS: P acnes biofilm formation on an unloaded synthetic calcium sulfate (CaSO4) bone void filler cement bead was evaluated by scanning electron microscopy over a period of 14 days. Beads loaded with tobramycin alone or vancomycin alone (as comparative controls) and beads loaded with a vancomycin-tobramycin dual treatment were assessed for their ability to eradicate planktonic P acnes, prevent biofilm formation, and eradicate preformed biofilms using a combination of viable-cell counts, confocal microscopy, and scanning electron microscopy. RESULTS: P acnes surface colonization and biofilm formation on unloaded CaSO4 beads was slow. Beads loaded with antibiotics were able to kill planktonic cultures of 106 colony-forming units/mL, prevent bacterial colonization, and significantly reduce biofilm formation over periods of weeks. Complete eradication of established biofilms was achieved with a contact time of 1 week. CONCLUSIONS: This study demonstrates that antibiotic-loaded CaSO4 beads may represent an effective antibacterial and antibiofilm strategy to combat prosthetic infections in which P acnes is involved.
Authors: Nan Jiang; Devendra H Dusane; Jacob R Brooks; Craig P Delury; Sean S Aiken; Phillip A Laycock; Paul Stoodley Journal: Sci Rep Date: 2021-01-14 Impact factor: 4.379