Review Question - QID 219793

A 59-year-old female presents to the emergency department with three months of increased pain in the right knee with associated erythema and swelling. The patient recently underwent a right total knee arthroplasty eight months ago, and at her three-month follow-up appointment was reported to be doing well. In the emergency department, the patient has a heart rate of 98 beats per minute, blood pressure of 128/82 mmHg, and temperature of 101.2°. A physical examination of the right knee shows +2 effusion, erythema surrounding the incision and extending over the anterior aspect of the knee, and a healed surgical incision without drainage from the incision. ESR 96 mm/hr, CRP 120 mg/L, and joint aspiration yields 30 cc of purulent sanguinous fluid, 65,000 WBC/microliter, with 90% PMN. What is the organism most likely found in microscopy evaluation and what is the next best step in management?