Rifampin, rifapentine, and rifabutin are active against intracellular periprosthetic joint infection-associated staphylococcus epidermidis

Staphylococcus epidermidis is a major cause of periprosthetic joint infection (PJI); its intracellular persistence within osteoblasts may compromise therapy if that therapy is not intracellularly active. The intracellular activity of rifampin, rifapentine, and rifabutin was assessed against five rifampin-susceptible and two rifampin-resistant S. epidermidis isolates. Compared to no treatment, treatment resulted in a $2-fold log₁₀ reduction of intracellular rifampin-susceptible, but not rifampin-resistant, S. epidermidis. These findings show activity of rifampin, rifapentine, and rifabutin against intraosteoblast PJI-associated S. epidermidis.