Bacterial interference--is deliberate colonization with Escherichia coli 83972 an alternative treatment for patients with recurrent urinary tract infection?

The increasing microbial antibiotic resistance motivates research for non-antibiotic treatment alternatives. In recurrent urinary tract infections (UTIs), 'bacterial interference' has attracted interest as a possible alternative treatment option. The observation that asymptomatic bacteriuria (ABU) protects against recurrent UTI has prompted clinical trials with deliberate colonization of the human urinary tract as an alternative approach in patients with recurrent UTI. The strain used for colonization, the ABU isolate Escherichia coli 83972, has been shown to cause symptom-free colonizations for long periods of time. Patients on long-term colonization report a subjective benefit, and UTI treatments are rare in colonized patients. This report presents an update on open long-term E. coli 83972 colonization trials and describes the design of an ongoing randomized trial.