Clonal relationships and extended virulence genotypes among Escherichia coli isolates from women with a first or recurrent episode of cystitis.

Abstract

To identify bacterial predictors of recurrence and/or persistence in acute cystitis, extended virulence genotypes were compared with clonal background and epidemiologic status among 74 Escherichia coli urine isolates from women with first or recurrent episodes of urinary tract infection (UTI). Sequential isolates from patients with recurrent UTI were classified, using macrorestriction analysis, as having caused an isolated recurrence versus a single or multiple same-strain recurrences. papA, papG allele II, iha, and iutA predicted multiple same-strain recurrences, whereas nfaE and the absence of sfaS or fyuA predicted isolated recurrences. Phylogenetic group B2 accounted for 70% of isolates and for most of the putative virulence factors (VFs) studied. The meningitis-associated O18:K1:H7 clonal group comprised 18% of isolates, exhibited multiple VFs, and caused "once-only" recurrences less commonly than did other strains. These findings identify specific VFs and clonal groups against which preventive interventions might be beneficial and illustrate the importance of delineating pathogenetically relevant subgroups within the "recurrent cystitis" population.