Colonizing Neurogenic Bladders With Benign Flora

The unifying goal of our work is to develop new approaches for the prevention of urinary tract infection (UTI) in persons with spinal cord injury (SCI). Most individuals with SCI have neurogenic bladders, and the resulting urinary stasis and bladder catheterization predispose them to recurrent UTI. Currently few, if any, measures are effective at prevention of UTI in persons with neurogenic bladders.

Bacterial interference, or using benign bacteria to prevent infection with virulent pathogens, may offer a solution to the significant problem of recurrent episodes of UTI in persons with SCI. Two trials in persons with SCI of instilling nonpathogenic Escherichia coli (83972) directly into the bladder demonstrated a strong association between colonization with this non-pathogen and decreased frequency of UTI. However, the successful colonization rate of the direct inoculation method was low (51-62%). Since a urinary catheter-associated biofilm, or bacteria plus extracellular matrix, continually seeds the bladder with bacteria, we proposed to use urinary catheters that had been pre-coated with a biofilm of E. coli 83972 as a means to achieve bladder colonization. Our recently completed pilot (B3248P) demonstrated that insertion of urinary catheters pre-coated with E. coli (83972) was an effective and safe method to achieve bladder colonization with this potentially protective strain. The rate of successful colonization with the E. coli-coated catheters was high (10 of 12 subjects, or 83%). However, this pilot was limited to the subpopulation of SCI veterans who utilize chronic indwelling catheters for bladder drainage.

The current proposal expands upon previous work by widening the range of eligible subjects and by simplifying the colonization protocol. Since an intermittent catheterization program (ICP) is a preferred and more common means of managing neurogenic bladders than chronic catheterization, we now plan to test E. coli 83972-coated catheters in persons with SCI who use ICP for bladder drainage. We hypothesize that short-term use (3 days) of E. coli 83972-coated catheters in persons with SCI practicing ICP will lead to successful colonization (persisting 28 days or more) in the majority of subjects. We will also record subjects' rates of symptomatic UTI while colonized with E. coli 83972 and compare these rates to the subjects' baseline rates in the year prior to study entry. Subjects will be able to remove their study catheters at home and to submit urine samples by mail, so the colonization process will simple and convenient. If successful colonization is achieved in this pilot trial, a larger clinical trial will be designed to test the efficacy of these catheters at preventing UTI in persons with SCI.