Urethral cultures in female patients with a spinal cord injury

Micro-organisms attached to the lumens and balloons of indwelling urinary catheters and correlation with symptoms, antibiotic use and catheter specimen of urine results

To determine micro-organisms attached to removed urethral catheters and relate this to patient-specific information. Indwelling urethral catheters were collected from patients at a UK teaching hospital. The balloon and lumen were sonicated, and micro-organisms were enumerated. Catheter specimen urine results were retrospectively reviewed. Escherichia coli and Enterococcus faecalis were the most common isolates from 61 catheters. 19.7% of patients received antibiotics and 25 % of those had a multi-drug-resistant (MDR) organism in the lumen. Only 2.04% of catheters from patients not receiving antibiotics had a MDR organism. All lumens were colonized irrespective of antibiotic use. Symptom presentation did not correlate with numbers of colonizing organisms or species. Despite heavy colonization, only 8/61 patients were symptomatic. Indwelling urinary catheters in place for ≥10 days were universally colonized and there was no correlation with symptom presentation. Symptom presentation remains the most important factor for defining catheter-associated urinary tract infection.

Urethral cultures in patients with spinal cord injury

STUDY DESIGN

Prospective analysis.

OBJECTIVES

To investigate the colonization of the distal urethra and bladder during the initial stages of rehabilitation in acute spinal-cord injury (SCI) and to examine the association between bacteriuria and colonization of the distal urethra.

SETTING

Selcuk University Meram Faculty of Medicine, Konya, Turkey.

METHODS

A total of 27 patients with SCI (13 females and 14 males) and 40 controls without evidence of disease of the urinary tract were studied. Cultures were taken from the patients who applied clean intermittent catheterization and compared with normal subjects.

RESULTS

Escherichia coli was predominantly isolated from the urine and urethral cultures of both female and male SCI patients. Colonization of other bacteria in the urine and urethral cultures was similar in both female and male patients, except for Pseudomonas, which was colonized in male patients. In all, 72% of patients who had E. coli positive urethral cultures also had E. coli colonization in their simultaneous urine cultures. There was concordance between urethra and urine cultures concerning the growth of E. coli (P=0.82). When urethral cultures collected 1 week before were evaluated in patients with E. coli positive urine cultures (n=24 cultures), 15 of these urethral cultures also had E. coli colonization. There was concordance between urethra and urine cultures concerning the growth of E. coli (P=0.66).

CONCLUSIONS

Our study suggested that urethral flora was a significant source for the development of urinary infection in spinal cord-injured patients.

Pathogenesis of bacteriuria and infection in the spinal cord injured patient

Spinal cord injury (SCI) produces profound alterations in lower urinary tract function. Incontinence, elevated intravesical pressure, reflux, stones, and neurological obstruction, commonly found in the spinal cord-injured population, increase the risk of urinary infection. The overall rate of urinary infection in SCI patient is about 2.5 episodes per patient per year. Despite improved methods of treatment, urinary tract morbidity still ranks as the second leading cause of death in the SCI patient.SCI removes the ability of the pontine micturition center and higher centers in the brain to inhibit, control, or coordinate the activity of the vesicourethral unit. As a result, a patient with complete quadriplegia is typically unaware of bladder activity. Bladder contraction is accompanied by vesicosphincter dyssynergia instead of sphincter relaxation. It is widely accepted that intermittent catheterization, when compared with indwelling catheters, reduces the risk of urinary tract infection (UTI) in SCI patients and is the preferred method of bladder drainage in this patient population. Attempts at eliminating bacteriuria associated with indwelling or intermittent catheters have generally been unsuccessful. There is now appreciation of the fact that a creeping adherent biofilm of bacteria frequently ascends through the luminal and external surfaces of an indwelling catheter, often within 8 to 24 hours, leading to bacterial adherence to the bladder surface and correlating with symptomatic infection. The use of antimicrobial agents to clear or prevent bacteriuria in patients on indwelling or intermittent catheterization has had mixed success. Treatment for asymptomatic bacteriuria in SCI patients remains controversial. SCI patients with symptomatic urinary infections should be treated with the most specific, narrowest spectrum antibiotics available for the shortest possible time. Guidelines for selecting antimicrobial agents in SCI patients are similar to guidelines for the treatment of complicated urinary infections in the general population. Characteristics of the quinolones make them well suited to treating UTI in the SCI patient.

Asymptomatic bacteriuria in spinal cord patients and the elderly

The prevalence and incidence of symptomatic and asymptomatic bacteriuria will remain high for many years to come. Antimicrobial agents are necessary to treat symptomatic UTI because no natural methods have been shown to be effective. Treatment of ABU is not appropriate. There is growing resistance to antibiotics, biocides, and antiseptics and, simultaneously, a decreasing rate of introduction of new antibacterial agents; thus the problem of resistance is magnified and potentially complicates the management of patients with SCI and elderly persons. New options of managing health and of preventing ABU and UTI and the complications arising from these diseases must be investigated vigorously and urgently. In particular, further study of the role of bacterial biofilms, the normal microflora, the influence of diet and hygiene, and the importance of the host immune response in the process of urinary tract colonization and infection is relevant and necessary.