title: Recurrence of urinary tract infections in adult patients with community-acquired pyelonephritis caused by E. coli: a 1-year follow-up.
abstract: In a prospective study, 42 women were followed for recurrence of urinary tract infections (UTIs) for 1 y after an index episode of community-acquired pyelonephritis caused by Escherichia coli. Altogether, 26 repeat episodes were detected. Of these, 20 occurred at least 1 month after the index episode 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: 52%, of the 29 women with previous UTI had at least 1 recurrence, compared with 15%, of the 13 patients without previous UTI. E. coli caused the majority (73%) of the recurrences. Genotype comparisons by RAPD-PCR analysis between E. coli isolates from a patient showed that 75%. of the original and recurrent strains were genetically non-identical. Of the 54 E. coli strains, 42 were carrying genes coding for G adhesins of P fimbriae: 40 isolates carried class II, I class III and 1 carried both class II and III G adhesin genes. Each of the virulence-associated factors (genes for G adhesins, MRHA, haemolysin, type 1C fimbriae, and O and K antigens) was evenly distributed among 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.
authors.affiliation: Department of Clinical Microbiology, Kuopio University Hospital, Finland.
authors.forename: U M
authors.initials: UM
authors.lastname: Kärkkäinen
authors.forename: R
authors.initials: R
authors.lastname: Ikäheimo
authors.forename: M L
authors.initials: ML
authors.lastname: Katila
authors.forename: A
authors.initials: A
authors.lastname: Siitonen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017714:Community-Acquired Infections / Q000382:microbiology; D004198:Disease Susceptibility; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D011704:Pyelonephritis / Q000150:complications / Q000382:microbiology*; D019105:Random Amplified Polymorphic DNA Technique; D012008:Recurrence; D012307:Risk Factors; D014552:Urinary Tract Infections / Q000382:microbiology*; D014774:Virulence