Bone and Joint Infections Caused by Staphylococcus lugdunensis

Staphylococcus lugdunensis is a coagulase-negative Staphylococcus with increasingly frequent recognition as an invasive pathogen with virulence properties more similar to those of Staphylococcus aureus than to those of Staphylococcus epidermidis. Staphylococcus lugdunensis is most frequently described as a cause of bacteremia and infective endocarditis. We report 2 patients with bone and joint infections due to S. lugdunensis and review the literature describing such illnesses. Case 1 is that of an 81-year-old woman with chronic back pain due to lumbar spinal stenosis who had rapidly progressive low back pain over the 2-week interval. She developed bacteremic L2-3 spondylodiscitis with contiguous osteomyelitis of distal L2 end plate and proximal L3 end plate. Staphylococcus lugdunensis was isolated from 2 sets of blood cultures and from a computed tomographic-guided aspirate of the L2-3 disk space. The patient was treated with 8 weeks of intravenous vancomycin and oral rifampin, with rapid resolution of back pain and return to baseline status. Case 2 is that of a 63-year-old man with osteoarthritis of the right knee who underwent outpatient arthroscopic surgery, at which time, he had a partial meniscectomy and chondroplasty. He subsequently developed postoperative septic arthritis due to S. lugdunensis treated with arthrocentesis, followed by arthroscopic washout together with 3 weeks of intravenous vancomycin and intravenous rifampin followed by 3 weeks of oral antibiotic therapy.