ARE RECURRENT UTI ASSOCIATED WITH MORE VIRULENT E.COLI?

Background and Aim : More than ۴۰% of women who experience acute cystitis developrecurrence which can be either relapse or reinfection based on the strains responsible for causationof new episode of cystitis. Present study was planned in order better insight of the host behaviouraland bacterial characteristics that are associated with recurrent UTI in women.Methods : A cohort of ۲۴۱ women with culture proven acute cystitis were followed up forrecurrence and their index episode E. coli was matched with recurrent strain(s) usingEnterobacterial RepetitiveIntergenic Consensus (ERIC) profiles. E. coli were further analyzed forphylogroups, virulence genotype, virulence score (VF score) and biofilm formation capability.Questionnaire-based data was collected from participants through interview for behaviouralpractices and psychosocial aspects associated with recurrent UTI.Results : ۴۶ women had culture confirmed recurrence by E. coli during follow-up of one year.Acute E. coli from ۲۲ women were classified as RI (recurrent infection) isolates as the index andfirst recurrence were caused by same strain of E. coli while remaining ۲۴ women were assigned toSI(single infection) group. Pathogenicity island gene malX (p=۰.۰۲), toxin gene cytotoxicnecrotizing factor cnf۱ (p=۰.۰۰) and VF score ((۱.۹۵ vs. ۱.۵۸, p =۰.۰۴).) were significantlyassociated with RI isolates. Phylogroup B۲ formed majority in RI isolates, whereas SI hadsignificant number of isolates belonging to phylogroup A. RI isolates were significantly betterbiofilm producers then SI isolates (p = ۰.۰۱). Family history of UTI in a first degree female relativeand constipation were the strongest independent risk factors for recurrent cystitis (OR=۲.۶۱,۹۵%CI=۱.۱۷-۵.۸۱; OR=۲.۶۱, ۹۵%CI=۱.۱۶-۵.۸۴), other included stress incontinence (OR=۲.۱۶,۹۵%CI=۱.۰۷-۴.۳۳).Conclusion : E. coli associated with recurrence had higher mean VF scores and stronger biofilmformation capability thus appear to be more virulent and malX seems to have a role in causingrecurrence. Many behavioural risk factors reflect cultural and ethnic lifestyle and most of the riskfactors for initial infection are potentially modifiable but sufficient to also pose risk for recurrence.

کلیدواژه ها:

UTI ، E. coli