Successful use of bacteriophage therapy for a <i>Staphylococcus aureus</i> prosthetic joint infection in Canada

Background: Prosthetic joint infections (PJIs) pose a significant treatment challenge due to biofilm-associated resistance, which limits antibiotic effectiveness. Bacteriophages, naturally occurring viruses that selectively infect and lyse bacteria, can disrupt biofilms, potentially enhancing antibiotic activity. We present the case of a male in his 70s with a history of total hip arthroplasty in 1973 who developed a chronic methicillin-susceptible Staphylococcus aureus (MSSA) PJI. Despite eight surgical interventions and multiple courses of suppressive antibiotics, the infection persisted, necessitating the use of bacteriophage therapy. Methods: The patient's MSSA isolate was sent to a bacteriophage laboratory in Quebec, who identified effective bacteriophages, and a two-bacteriophage cocktail was selected. Following approval by Health Canada and the University of Calgary (REB23-1733), bacteriophages were administered during a planned incision and drainage (I&amp;D). Locally, bacteriophage was applied topically into the hip, followed by 2 weeks of twice-daily intravenous bacteriophage therapy with standard-of-care intravenous antibiotics. Results: Therapy was well tolerated except for initial mild rigors. Now, 24 weeks after bacteriophage administration, there is cessation of pain, normalization of inflammatory markers, and significant improvement in quality of life while continuing on suppressive antibiotics. Conclusion: Bacteriophage therapy was safe in our case, and emerging evidence is promising for its use in PJIs. However, regulatory hurdles, cost, and lack of standardized protocols currently limit its use. Classified as experimental therapy in Canada, bacteriophage use is restricted to clinical trials. This case underscores the potential for broader adoption of bacteriophage therapy in managing PJIs across Canada.