This is a single-patient, phase I/II clinical trial that aims to evaluate the potential of a bacteriophage cocktail to treat and prevent the recurrence of a methicillin-susceptible Staphylococcus aureus prosthetic joint infection of the hip. The patient has exhausted all conventional therapies, both surgical and medical, at considerable detriment to his quality of life. The treatment involves a one time, intra-operative injection of bacteriophages into the joint and 14 days of intravenous phage therapy. The goal is to eliminate the infection and prevent further complications, providing a potential new treatment avenue for patients with difficult-to-treat infections.

This study is a single-patient, phase I/II clinical trial that addresses a challenging case of a recurrent methicillin-sensitive Staphylococcus aureus (MSSA) infection in a prosthetic hip joint despite extensive antibiotic treatments and multiple surgeries.

Given the failure of conventional treatments and the high risk associated with major surgical interventions, this study explores the use of bacteriophage therapy as an innovative alternative. Bacteriophages, viruses that specifically infect and lyse bacterial cells, offer a patient-specific, targeted approach to combating bacterial infections within biofilms. Our study will use a bacteriophage cocktail containing phages BP13 and J1P3, both of which have demonstrated in-vitro activity against the patient's strain of S. aureus.

The treatment protocol involves the administration of phages intra-articularly on day 1 and intravenously twice daily on days 1-14. This dual approach aims to enhance the efficacy of the phage therapy by ensuring both systemic and localized delivery of the phages to the infected site.

The primary outcome will be the resolution of the infection, indicated by the absence of clinical symptoms such as wound drainage, swelling, erythema, pain, and fever, as well as the normalization of inflammatory markers over a 12-month period following the phage therapy.

Throughout the study, the patient's safety and response to the treatment will be rigorously monitored through regular physical examinations, blood tests, and if needed, imaging studies. The initial dose of the phage cocktail will be administered in a hospital setting to monitor for any immediate adverse reactions Follow-up assessments will continue for a year to ensure long-term efficacy and safety.

The goal of this study is to demonstrate the potential of bacteriophage therapy as a viable treatment option for prosthetic joint infections, particularly those resistant to standard treatments. Success in this case could pave the way for broader applications of phage therapy in managing complex bacterial infections, offering a new avenue for treatment where traditional methods have failed.

Inclusion Criteria:

• Diagnosis of active chronic prosthetic joint infection
• Causative bacteria is susceptible to bacteriophage therapy in vitro
• History of multiple failed antibiotic and surgical interventions

Exclusion Criteria:

• Stage 5 chronic kidney disease
• Cirrhosis
• A known allergy to phage products
• Fever
• Involvement in another clinical trial
• Pregnancy