Pathogenesis of Staphylococcus epidermidis prosthetic joint infections: bacterial adhesion and internalization in osteoblasts, synoviocytes and endothelial cells

Staphylococcus epidermidis is frequently isolated during prosthetic joint infections (PJIs). Unlike Staphylococcus aureus, its internalization and persistence within cells are controversial. We aimed to determine whether internalization is involved in the pathophysiology of S. epidermidis PJIs. Adhesion and internalization of S. epidermidis PJI isolates have been studied using an in vitro model. Despite similar adhesion levels to the S. aureus SH1000 reference strain, S. epidermidis isolates had a low internalization in osteoblasts, synoviocytes and endothelial cells. Internalization of S. epidermidis is strain- and cell-type dependent. Our results do not support S. epidermidis internalization as a key factor in PJIs.