Immunology and Host ResponseRecurrent ESBL Escherichia coli Urosepsis in a Pediatric Renal Transplant Patient Treated With Antibiotics and Bacteriophage TherapyGainey, Andrew B. PharmD*; Daniels, Robert PharmD*; Burch, Anna-Kathryn MD†; Hawn, Jason MD‡; Fackler, Joseph MS§; Biswas, Biswajit PhD¶; Brownstein, Michael J. MD, PhD§ Author Information From the *Department of Pharmacy, Division of Pediatric Infectious Diseases, Prisma Health Children’s Hospital—Midlands, Columbia, South Carolina †Department of Pediatrics, Division of Pediatric Infectious Diseases, Prisma Health Children’s Hospital—Midlands, Columbia, South Carolina ‡Department of Pediatrics, Division of General and Hospital Pediatrics, Prisma Health Children’s Hospital—Midlands, Columbia, South Carolina §Adaptive Phage Therapeutics, Gaithersburg, Maryland ¶Department of Genomics & Bioinformatics, Biological Defense Research Directorate, Naval Medical Research Center, Frederick, Maryland. Accepted for publication September 1, 2022 No funding was received for this single patient emergency IND but the part of the work conducted by NMRC was supported by Work Unit #A1417 Dr. Mike Brownstein has equities in Adaptive Phage Therapeutics. All the authors contributed significantly to the composition and editing of the article. A.G., R.D., A.B., and J.H. were responsible for direct patient care and treatment. J.F., B.B., and M.B. through Adaptive Phage Therapeutics and the Navy Medical Research Center, provided a phage cocktail as well as clinical guidance. The views expressed in this journal article reflect the results of research conducted by the authors and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, nor the United States Government. All the authors have read and approved the article. This article has not been previously published and is not under consideration for publication elsewhere. This article discusses the use of phage therapy which is not an FDA approved agent. B.B. is a federal employee of the United States government. This work was prepared as part of his official duties. Title 17 U.S.C. 105 provides that “copyright protection under this title is not available for any work of the United States Government.” Title 17 U.S.C. 101 defines a U.S. Government work as work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties. All appropriate procedures, according to the FDA and our institutional review board, were followed. Written informed consent was obtained from the patient’s legal guardians. Address for correspondence: Andrew B. Gainey, PharmD, Prisma Health Children’s Hospital–Midlands, 7 Medical Park Rd, Columbia, SC 29203. E-mail: [email protected]h.org; Robert Daniels, PharmD, Prisma Health Children’s Hospital–Midlands, 7 Medical Park Rd, Columbia, SC 29203. E-mail: [email protected]. The Pediatric Infectious Disease Journal 42(1):p 43-46, January 2023. | DOI: 10.1097/INF.0000000000003735 Buy Metrics Abstract Introduction: Treating recurrent multidrug resistant (MDR) urosepsis in pediatric transplant recipients can be challenging. Particularly when antibiotics fail to prevent future occurrence and the nidus is seemingly undiscoverable. While there is an increasing amount of data on phage therapy, to our knowledge, there are no published cases involving pediatric renal transplant recipients. Therefore, we present a challenging clinical case in which phage therapy was used in a pediatric renal transplant recipient who developed recurrent MDR urosepsis with an unclear source. Case Presentation: Our patient was a 17-year-old female who initially developed urosepsis caused by extended-spectrum β-lactamase (ESBL) Escherichia coli, while being treated with an immunosuppressant regimen because of kidney rejection secondary to poor immunosuppression therapy compliance. She was admitted to our hospital intermittently for 4 months with 4 episodes of urosepsis caused by ESBL E. coli. She received multiple courses of antibiotics (mainly ertapenem) and underwent a fecal material transplant to eradicate her ESBL E. coli colonized gastrointestinal tract. Because of recurrent development of urosepsis after antibiotic treatment, she later underwent treatment with a phage cocktail consisting of 2 isolate-specific phages. After a prolonged antibiotic course and subsequent 3-week intravenous phage treatment, she had no ESBL E. coli in her urinary cultures for 4 years post-treatment. Discussion: This case highlights the challenges of treating recurrent ESBL E. coli infections in a pediatric renal transplant patient and provides evidence that phage therapy may prove useful in such cases. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.