Expression of virulence factors among Escherichia coli isolated from the periurethra and urine of children with neurogenic bladder on intermittent catheterization

Background, Patients with neurogenic bladder caused by spinal cord injury o r myelomeningocele empty their bladder several times a day by intermittent catheterization, Bacteriuria without symptoms of infection is frequently pr esent in these patients. Occasionally a clone of Escherichia coil that has been carried for weeks without symptoms causes a symptomatic urinary tract infection. Virulence factors are commonly expressed among E. coli causing i nfection in patients with normal urinary tracts. However, it is unknown whe ther expression of virulence factors by an E. coli clone colonizing the neu rogenic bladder increases the risk of subsequent infection. In this study w e examined the prevalence of virulence factor expression among E, coli isol ated from the periurethra and urine of patients with neurogenic bladder. Methods, The prevalence of virulence factors was examined among E. coli iso lated from the periurethra and urine in patients with neurogenic bladder wh o received intermittent catheterization and were followed for 6 months. Rep resentative isolates from the 37 clonal types off. coli detected in the per iurethra and urine of children with neurogenic bladder were assessed for O antigen, hemolysin, aerobactin, serum resistance and type I and P-adhesin. Results. All clones were serum-resistant and expressed type I adhesin, none expressed aerobactin and two expressed hemolysin. The presence of P-adhesi n was not unique to clones associated with symptomatic infection. The prese nce of P-adhesin carried for weeks in a clone did not predict subsequent in fection in the neurogenic bladder. Conclusion. Bacterial virulence factors did not predict infection of the ne urogenic bladder.