Cellulose and PapG are important for Escherichia coli causing recurrent urinary tract infection in women

To identify Escherichia coli factors associated with bacterial persistence in the human urogenital tract using well-defined clinical isolates from women with cystitis.

E. coli were isolated from women suffering from recurrent cystitis. For comparison, isolates from sporadically infected patients and healthy volunteers were included in the analysis. Samples were taken on three occasions from the urine, periurethra, and vagina. Isolates were typed by pulsed-field gel electrophoresis, and virulence factors were detected by PCR and morphotypic analysis.

In all patients, the original E. coli strain was isolated repeatedly and from different regions. The presence of papG coding for a P fimbriae subtype linked to pyelonephritis was associated with strains isolated from patients with recurrent cystitis, including both among urinary and vaginal isolates. The biofilm component cellulose was detected at a higher frequency in urinary isolates from recurrent versus sporadic cystitis.

The hypothesis of a periurethral/vaginal E. coli reservoir is supported by the results of this study. Our results also indicate an impact of cellulose on E. coli persistence in the human urogenital tract.