Prosthetic Joint Infections (PJIs) are increasing with the use of orthopedic devices on an ageing population. Cutibacterium acnes is a commensal organism that plays an important role in the ecosystem healthy human skin, yet this species is also recognized as a pathogen in foreign body infection: endocarditis, prostatitis and specifically in PJIs. C. acnes is able to escape the immune system. This phenomenon could reflect two bacterial behavior: the bacterial internalization by host cells and the biofilm formation.

The aim of the study is to evaluate specific pathogenicity factors (ability to internalize bone cells and ability to form a biofilm) of bacteria derived from clinical strains of C. acnes isolated from bone infections on orthopedic material.

Inclusion Criteria:

• bone infection with C. acnes,
• isolation of the strain,
• presence of a single species,
• conservation of a viable strain,
• patients over 18 years

Patients with Cutibacterium acnes bone infections