A Case of Persistent Intra-Abdominal Stenotrophomonas maltophilia Infection Despite Bacteriophage Therapy.

Multidrug resistant infections are a challenge in the health care setting and a cause of patient morbidity and mortality. Bacteriophages (phages) are viruses that target and kill bacteria and have been used in patients to treat bacterial infections. We present a case of disseminated Stenotrophomonas maltophilia infection, with pulmonary, intra-abdominal and bloodstream involvement. The patient was treated with a combination of antibiotics and personalized phage therapy, administered daily for 12 days both intravenously as well as via intra-abdominal drains. Phage therapy was well-tolerated, the patient cleared S. maltophilia from their bloodstream and their intra-abdominal abscesses were stable or decreased in size. However, the intra-abdominal fluid cultures remained positive for S. maltophilia. Unfortunately, the patient passed away 2 months after completion of phage therapy due to multiorgan failure. These data highlight the difficulty of treating critically ill patients and clearing complex, biofilm mediated infections, even with phages. More information is needed regarding the optimal treatment protocols for phage therapy in complex multifocal infections.

The Safety and Toxicity of Phage Therapy: A Review of Animal and Clinical Studies.

Increasing rates of infection by antibiotic resistant bacteria have led to a resurgence of interest in bacteriophage (phage) therapy. Several phage therapy studies in animals and humans have been completed over the last two decades. We conducted a systematic review of safety and toxicity data associated with phage therapy in both animals and humans reported in English language publications from 2008-2021. Overall, 69 publications met our eligibility criteria including 20 animal studies, 35 clinical case reports or case series, and 14 clinical trials. After summarizing safety and toxicity data from these publications, we discuss potential approaches to optimize safety and toxicity monitoring with the therapeutic use of phage moving forward. In our systematic review of the literature, we found some adverse events associated with phage therapy, but serious events were extremely rare. Comprehensive and standardized reporting of potential toxicities associated with phage therapy has generally been lacking in the published literature. Structured safety and tolerability endpoints are necessary when phages are administered as anti-infective therapeutics.