In July 2018, a 21-year-old man was hospitalized after a road accident with open comminuted proximal right femoral and acetabular fractures, laceration of the right lower hand, and hemorrhagic shock. Wound debridement, fasciotomy, femur fracture stabilization with gamma nail, and tissue reconstruction were performed on the 14th of July. On consecutive days, the patient developed secondary MDR P. aeruginosa, carbapenem-resistant Acinetobacter baumannii, and vancomycin-resistant Enterococcus faecium (VRE) wound infections and multiple organ dysfunction syndrome. The patient underwent five debridement procedures and therapy using a wound vacuum system. Broad-spectrum IV antimicrobial treatment with meropenem, colistin, piperacillin-tazobactam, linezolid, and fluconazole was administered, and renal replacement therapy was initiated. Regardless of the treatment, the patient developed an osteosynthesis-associated infection and osteomyelitis, and repeatedly positive wound cultures grew with VRE, MDR P. aeruginosa, and MDR A. baumannii. On the 13th of August, the gamma nail was removed, and proximal femoral segment resection was performed, followed by tissue reconstruction and lower leg external fixation. Based on the antibiogram, the antimicrobial regimen was changed to intravenous fosfomycin, meropenem, and colistin. On the 13th of September, the right thigh wound was closed using a scapular flap. The patient's condition improved gradually, and there were no signs of systemic or local inflammation. Repeated cultures of the wound were negative. The patient was discharged on the 15th of October with IV meropenem and colistin treatment, which was discontinued after two weeks due to acute kidney injury, presumably colistin-induced nephrotoxicity. In November, purulent discharge from the right upper tight appeared. Computed tomography with contrast injection in the cutaneous wound opening revealed a fistula that connects femoral head and skin on the right upper third of the lateral femur surface (Figure 1A). The patient underwent fistulotomy, and MDR P. aeruginosa and VRE were isolated from the wound. With a presumptive diagnosis of recurrent femoral osteomyelitis, two-stage surgery was planned to preserve hip replacement surgery in the future. Local bacteriophage therapy was planned using the bacteriophage cocktail BFC 1.10 produced at Queen Astrid Military Hospital in Brussels, Belgium, consisting of phages active against P. aeruginosa and S. aureus.
The treatment was performed according to Paragraph 37 of the Declaration of Helsinki. The patient provided written informed consent for the use of the bacteriophages. On the 5th of December, a right femoral head excision was performed and replaced with colistin-impregnated cement spacer. The proximal femoral culture was positive for MDR P. aeruginosa, VRE, and Staphylococcus epidermidis. The pathology and intraoperative findings confirmed femoral head osteomyelitis with fistula (Figures 1B,C). After surgery, the patient was treated with IV colistin for 7 days and linezolid for 23 days. On the 7th of December, 2,000 mL of BFC 1.10 cocktail with 107 plaque-forming units (PFU) per mL of each phage were shipped to Latvia. Prefilled sterile containers containing 30, 40 or 50 mL of phage solution were prepared under sterile conditions. Three days before the procedure, the patient was treated with IV ceftazidime-avibactam, which was continued for 15 days. On the 13th of December, bone cement was removed; wound and acetabular cultures were taken, and were positive for MDR P. aeruginosa. Next, wound rinsing with 50 mL BFC 1.10 bacteriophage suspension was performed intraoperatively, tissue damage was replaced with a serratus muscle flap, and an irrigation system for local bacteriophage application was installed (Figure 1D). For the first 7 days, the patient was treated with 40 mL (1 ml/min) of BFC 1.10 three times daily and then with 30 mL (1 ml/min) of BFC 1.10 two times daily via an irrigation catheter for another 7 days. The wound was rinsed with 50 ml of 4.2% sodium bicarbonate solution before the phage application using syringe. Together with the local phage treatment, linezolid and ceftazidime-avibactam were continued. During and after phage treatment on days 1, 3, 4, 7, 10, and 15, no bacterial cultures from the wound grew. Phages were isolated from the wound in the morning buffer sample before phage administration on days 1, 3, 4, 7, 10, and 15. At the end of treatment, the wound healed with no local or systemic signs of infection. When the irrigation catheter was removed, the tip of the catheter was positive for Candida tropicalis, which was not treated (Figure 2). No adverse effects, such as fever, local rash, itchiness, or other symptoms, were noted during phage therapy. Patient was discharged with lower leg external fixation until hip replacement surgery. Two months later, the wound healed and there were no signs of inflammation (Figure 1E) that was reassured with magnetic resonance imaging (MRI) of the right hip. Three months after phage treatment, computed tomography of the right hip and femur revealed no fluid collection or signs of osteomyelitis. In the following six months, two punctures from the right femur were performed and were culture negative, three months before hip replacement lower leg external fixation was removed. On the 3rd of September 2019, a hip replacement with a silver-coated implant was performed. During the surgery bacterial cultures were taken, the distal part of the femur was positive for MDR P. aeruginosa and VRE (fosfomycin susceptible), but acetabular bone and proximal part muscular tissue were culture negative. Patient received one dose of IV vancomycin for perioperative prophylaxis and IV colistin that was continued until microbiology results. Once the cultures came back positive patient was kept on IV colistin and IV fosfomycin. Sixteen days later DAIR (debridement, antibiotics and implant retention) was performed because of hematoma development and possible prosthesis infection, swabs taken during the surgery from periprosthetic tissue in distal segment were positive for MDR P. aeruginosa. On 4th of October punctures from periprosthetic tissue were performed and were culture negative. Three days later patient was discharged and continued antimicrobial therapy in outpatient setting with colistin and fosfomycin. For this episode patient received colistin for six weeks and fosfomycin for five months. During the follow-up period a year later, there were no local signs of infection, and the patient noted limited mobility in the right leg; however, he could continue to play basketball. Radiography of the right hip and femur 15 months later did not reveal any signs of inflammation (Supplementary Figure 1).