Can antimicrobial peptides provide an improved antimicrobial strategy for treatment of Cutibacterium acnes prosthetic joint infection?

Authors: Bruni, Gillian

Submitted to: Microbiology Spectrum
Publication Type: Other
Publication Acceptance Date: 8/13/2025
Publication Date: 9/8/2025
Citation: Bruni, G.O. 2025. Can antimicrobial peptides provide an improved antimicrobial strategy for treatment of Cutibacterium acnes prosthetic joint infection?. Microbiology Spectrum. 13(5). Article e02523-24. https://doi.org/10.1128/spectrum.02523-24.
DOI: https://doi.org/10.1128/spectrum.02523-24

Interpretive Summary: With increasing antibiotic resistance and a lack of new antibiotics in development, it is important to explore new strategies to improve antibiotic effectiveness as well as identify new antimicrobial approaches for bacterial infections. This is an invited commentary on a recent study published in Microbiology Spectrum exploring the use of special synthesized peptides that inhibit or kill bacteria. Specifically, the researchers investigated the ability of the peptides to treat joint infections caused by the skin bacterium, Cutibacterium acnes. Some of the peptides demonstrated antimicrobial and/or antibiofilm activity. Peptides and antibiotics used in combination showed that co-administration could lower the concentration of antibiotics required to control bacterial growth. Additionally, some peptides also successfully reduced internalization of bacterial cells by bone cells. Further studies are needed toward developing broad antimicrobial strategies to fight C. acnes joint infections and beyond. Further development of antimicrobial peptide technology is likely to find additional applications and broader impact on dental biofilms, and control of plant pathogens and industrial biofilms.

Technical Abstract: With increasing antibiotic resistance and the paucity of new antibiotics in the development pipeline, exploration of antimicrobial peptide applications alone or in combination with existing antibiotics may be more crucial than ever. The recent study by Varin-Simon, J., Haney, E.F., Colin, M., Velard, F., et al. (Microbiol Spectr 13(5): e02523-24, 2025, https://doi.org/10.1128/spectrum.02523-24,) reported on the use of synthetic D-amino acid host defense peptides (HDF) to mitigate C. acnes -mediated anaerobic prosthetic joint infections (PJI). Two of the synthetic HDPs, DJK5 and AB009-D, exhibited antimicrobial activity against not only planktonic C. acnes but also reduced adherence to titanium surfaces, while AB101-D inhibited C. acnes strain C2 preformed biofilm. Moreover, co-administration of some HDPs with antibiotics showed 1-2 fold reduction in antibiotic MIC values. Finally, the D-amino acid HDPs AB009-D and AB101-D significantly reduced osteoblast internalization of C. acnes, potentially via bactericidal activity. Further studies are needed toward developing multi-faceted, innovative antimicrobial strategies to mitigate not only C. acnes PJI but also broader applications including control of various bacterial infections, dental biofilms, plant pathogens, and industrial biofilms.