Osteomyelitits Due to Linezolid-Resistant Staphylococcus epidermidis

To the Editor—Described are the first reported cases of osteomyelitis due to linezolid-resistant Staphylococcus epidermidis. Case 1 was a 73-year-old woman with severe peripheral vascular disease and a recent diagnosis 6 months prior to admission of polymicrobial osteomyelitis of the left calcaneus, which had required multiple heel debridements, partial calcanectomy, and a skin grafting procedure. Linezolid and piperacillintazobactam were administered throughout her surgical course and for 6 weeks following her skin graft, at which time she was switched to linezolid monotherapy (linezolid was eventually discontinued 2 weeks prior to admission). She was admitted after a fall at home and was found to have purulent drainage from her left lower extremity graft with exposed bone. Imipenem-cilastatin was started empirically, and linezolid was added 2 days later. A deep wound swab obtained 2 days after admission isolated a coagulase-negative staphylococcus species that was not subjected to further laboratory testing. Surgical intervention was delayed due to initial patient refusal but was ultimately performed 2 weeks later. Bone cultures obtained intraoperatively isolated linezolid-resistant S. epidermidis (Table 1). The patient was eventually treated successfully with intravenous vancomycin and extensive plastic surgery. Case 2 was a 55-year-old man with chronically infected patellar hardware and associated left patellar osteomyelitis. He had been receiving linezolid for 6 weeks prior to admission from an outside prescriber following his most recent patellar debridement. He presented after a fall at his long-term acute care facility and was found to have a swollen left knee with purulent drainage. Culture of this drainage grew