Clearance of Vancomycin-Resistant Enterococcus Concomitant With Administration of a Microbiota-based Drug Targeted at Recurrent Clostridium difficile Infection

Erik R. Dubberke,1 Kathleen M. Mullane,2 Dale N. Gerding,3,4 Christine H. Lee,5 Thomas J. Louie,6 Harriet Guthertz,7 and Courtney Jones8

1Department of Medicine,Washington University School of Medicine, St. Louis, Missouri; 2Section of Infectious Diseases and Global Health, University of Chicago Medicine, 3Department of Medicine, Loyola University Chicago Stritch School of Medicine, Maywood, and 4Edward Hines Jr. Veterans Affairs Hospital, Hines, Illinois; 5Department of Medicine, McMaster University, Hamilton, Ontario, and 6Departments of Medicine and Microbiology-Immunology and Infectious Diseases, University of Calgary, Alberta, Canada; 7Medical Marketing and Communications, Inc., St. Paul, Minnesota; and 8Rebiotix Inc., Roseville, Minnesota

Clearance of vancomycin-resistant Enterococcus concomitant with administration of a microbiota-based drug targeted at recurrent Clostridium difficile infection

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Open Forum Infect Dis. 2016;3 (3)


Vancomycin-resistant Enterococcus (VRE) is a major healthcare-associated pathogen and a well known complication among transplant and immunocompromised patients. We report on stool VRE clearance in a post hoc analysis of the Phase 2 PUNCH CD study assessing a microbiota-based drug for recurrent Clostridium difficile infection (CDI).


A total of 34 patients enrolled in the PUNCH CD study received 1 or 2 doses of RBX2660 (microbiota suspension). Patients were requested to voluntarily submit stool samples at baseline and at 7, 30, and 60 days and 6 months after the last administration of RBX2660. Stool samples were tested for VRE using bile esculin azide agar with 6 µg/mL vancomycin and Gram staining. Vancomycin resistance was confirmed by Etest.


VRE status (at least 1 test result) was available for 30 patients. All stool samples for 19 patients (63.3%, mean age 61.7 years, 68% female) tested VRE negative. Eleven patients (36.7%, mean age 75.5 years, 64% female) were VRE positive at the first test (baseline or 7-day follow-up). Of these patients, 72.7%, n = 8 converted to negative as of the last available follow-up (30 or 60 days or 6 months). Of the other 3: 1 died (follow-up data not available); 1 patient remained positive at all follow-ups; 1 patient retested positive at 6 months with negative tests during the interim.


Although based on a small sample size, this secondary analysis demonstrated the possibility of successfully converting a high percentage of VRE-positive patients to negative in a recurrent CDI population with RBX2660.

Clinical Trials Registration: NCT01925417.
Keywords: Clostridium difficile, microbiota-based drug, RBX2660, vancomycin-resistant, Enterococcus, VRE.