Recurrence of urinary tract infections in adult patients with community-acquired pyelonephritis caused by E. coli: A 1-year follow-up

In a prospective study, 42 women were followed for recurrence of urinary tr act infections (UTIs) for 1 y after an index episode of community-acquired pyelonephritis caused by Escherichia coil. Altogether, 26 repeat episodes w ere detected. Of these, 20 occurred at least 1 month after the index episod e and were regarded as recurrences. In all, 40% (17 of 42) of the women had recurrences. An earlier history of UTI increased the risk of recurrence: 5 2% of the 29 women with previous UTI had at least 1 recurrence, compared wi th 15% of the 13 patients without previous UTI. E. coil caused the majority (73%) of the recurrences. Genotype comparisons by RAPD-PCR analysis betwee n E. coli isolates from a patient showed that 75% of the original and recur rent strains were genetically non-identical. Of the 54 E, coli strains, 42 mere carrying genes coding for G adhesins of P fimbriae: 40 isolates carrie d class II, 1 class III and 1 carried both class II and III G adhesin genes . Each of the virulence-associated factors (genes for C adhesins, MRHA, hae molysin, type 1C fimbriae, and O and K antigens) was evenly distributed amo ng E. coli isolates of index episodes, independent of the recurrences. The index isolates: however, had more virulence-associated factors than did the isolates from the recurrences which were mainly due to lower UTIs.