Case 22

Patient #22, a 69 year-old woman with a past medical history of chronic kidney disease, hypothyroidism, severe congestive heart failure with reduced ejection fraction, prosthetic knee joint infection, and a history of bacteremia. In November 2016, she had a left ventricular assist device (LVAD) placed and a right knee arthroplasty. Over a 4 year period she developed multiple infections of her LVAD driveline and prosthetic joint infections resistant to multiple antibiotics. In June 2019 she had a right knee incision and drainage procedure and a 1-stage revision. Her LVAD driveline was also debrided, she was discharged to rehabilitation on ceftolozane-tazobactam for a P. aeruginosa in her drive line and right knee and oral amoxicillin for E. faecalis in her drive line. Meropenem was added in June 2019 because her driveline isolate was resistant to ceftolozane-tazobactam. She had recurrent P. aeruginosa bacteremia in December 2019 after stopping ceftolozane/tazobactam (by her choice) in November 2019. These P. aeruginosa isolates had similar susceptibilities to those isolated in June 2019. Three P. aeruginosa isolates (from blood, right knee and drive line) were tested for phage susceptibility. Two matching phage were provided in February 2020 and the patient received her first phage intravenously along with ceftolozane/tazobactam and oral amoxicillin. Her C-reactive protein levels fell from 61 to 31.7 over her 3 weeks and her erythocyte sedimentation rate decreased from 104 to 89. Her LFTs were normal during most of her phage therapy, although she was noted to slightly increase in March 2020. Soreness in her knee joint decreased during her four weeks phage course. She was able to walk more on her knee and has had minimal driveline drainage. This case is ongoing.