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.