Correlation of periurethral bacterial flora with bacteriuria and urinary tract infection in children with neurogenic bladder receiving intermittent catheterization.

Periurethral bacteria are inoculated daily into the urine of children with neurogenic bladder during clean intermittent catheterization (CIC). We examined how frequently periurethral bacterial species produced bacteriuria in children followed longitudinally. When Escherichia coli was detected on the periurethra, bacteriuria was also present 93% of the time. When Klebsiella, Pseudomonas, or Enterococcus species or nonpathogens were detected on the periurethra, bacteriuria was present 80%, 40%, 40%, and 25% of the time, respectively. Clonal typing of multiple colonies of E. coli from each periurethral and urine culture revealed that children carried only one or two E. coli clones in their urinary tracts over months of surveillance. When E. coli was detected in the urine, the identical clone was on the periurethra. E. coli persisted for weeks in the urine without causing symptoms. Occasionally the same E. coli clone carried for weeks caused a urinary tract infection. Bacteriuria frequently occurs after inoculation of periurethral E. coli into the urine during CIC.