Colonizing Neurogenic Bladders With Benign Flora

The purpose of the research is to determine whether we can get harmless bacteria to live in the bladders of persons with spinal cord injury who practice intermittent bladder catheterization. We will also look at whether having the harmless bacteria in the bladder prevents urinary tract infections from occurring.

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.

All patients in this pilot study were in the treatment arm, which consisted of receiving a urinary catheter that had been pre-coated with a biofilm of E. coli.

Bladder colonization was defined when (≥102 cfu/ml) of E. coli 83972 was detected in urine cultures for > 3 days after catheter removal.

Symptomatic UTI was defined as significant bacteriuria (≥105 cfu/ml) and pyuria (>10 WBC/hpf) plus ≥1 of the following signs and symptoms for which no other etiology could be identified: fever (oral temperature >100°F), suprapubic or flank discomfort, bladder spasm, change in voiding habits, increased spasticity, or worsening dysreflexia. The rate of UTI (number) was calculated by dividing the total number of patient days by the total number of UTIs.

Inclusion Criteria: Patients followed at the MEDVAMC who have sustained spinal cord injury > 12 months earlier, suffer from neurogenic bladder, practice intermittent bladder catheterization, and who have had at least 1 symptomatic UTI in the past will be enrolled. Exclusion Criteria: Exclusion criteria will include obstructive urolithiasis, indwelling bladder or nephrostomy catheters, supravesical urinary diversion, vesicoureteral reflux, active malignancy, uncontrolled diabetes mellitus, AIDS, requirement for immunosuppressive medication, or current antibiotic therapy. Women of childbearing age must have a negative pregnancy test before enrolling in the study, and they must utilize effective birth control methods during the study and for 3 months after the study is concluded.

Burns AC, Petersen NJ, Garza A, Arya M, Patterson JE, Naik AD, Trautner BW. Accuracy of a urinary catheter surveillance protocol. Am J Infect Control. 2012 Feb;40(1):55-8. doi: 10.1016/j.ajic.2011.04.006. Epub 2011 Aug 3.