Staphylococcus Intermedius Infections: Case Report and Literature Review
A 73 year old Caucasian female with a history of severe osteoarthritis developed fever, pain, redness, and swelling of her left elbow one month following a revision left elbow total arthroplasty. The original arthroplasty 10 years earlier had been complicated by infection that was successfully treated with several weeks of intravenous antibiotics according to the patient; the details of this remote infection and treatment were unattainable. She was subsequently well for many years without antibiotics until about 2 years prior to presentation when she began to develop gradually progressive joint instability and pain. She was admitted for elective total arthroplasty of the left elbow. Following surgery, she noted continuous serosanguinous drainage. Her orthopedist aspirated the joint on post-operative day 22. The joint fluid was described as cloudy with 26,000 red blood cells, 1300 white blood cells and 31% neutrophils. No organisms were seen on Gram stain, and bacterial cultures were negative. Patient was not started on antibiotics at this time. A few days later (post-operative day 25) she developed progressive elbow pain and fever and was admitted to the hospital. On admission, her temperature was 102.2°F and her white blood cell count was 11,000 cells/mm.\nOn surgical exploration, a large fluid collection was found in the elbow. The joint capsule appeared intact, however both wound and joint fluid cultures grew S. intermedius, as identified by the Vitek II automated microbiology system without further subspeciation. The wound was irrigated but the elbow prosthesis was not removed. Blood cultures were negative. In accordance with CLSI standards, the elbow isolates were determined to be resistant to penicillin and tetracycline but susceptible to oxacillin, erythromycin, clindamycin, chloramphenicol, gentamicin, rifampin, levofloxacin, linezolid, and vancomycin. The patient was treated with intravenous cefazolin and rifampin for six weeks and then transitioned to oral levofloxacin and rifampin with plan for a prolonged course given retention of infected prosthesis. She has not had any recrudescence of disease after 10 months on this regimen and will be reevaluated for possible cessation of therapy at one year’s time.\nThe patient was an avid dog lover. Although she did not recall her dog licking or biting her elbow after surgery, she did report that her dog frequently licked her face. She admitted to frequent close contact with her dog including sharing her bed at night. She denied any recent illness or skin lesions in her dog.