Patient #14, a 61-year-old male who suffers from bilateral knee osteoarthritis. In 2008, the patient had a right TKA which was complicated by several infections between 2009-2018 (treated with I & D and intensive antibiotic regimen), which lead to a spacer removal and replacement of the distal femoral modular component within the knee in 2019. At the site of surgery, his right knee became infected with an MDR, Klebsiella pneumoniae. The patient received 6 weeks of phage therapy via IV at a titer of 5e10 and ~20 EU/mL and experimental antibiotic cefidericol. The swelling seen at the site of infection dramatically decreased after the first infusion and at the end of therapy the patient had significant improvements in mobility, and blood testing results. Sensitivity testing showed that the bacterial isolate had developed resistance to the experimental antibiotics during therapy.