Predictive value of Escherichia coli susceptibility in strains causing asymptomatic bacteriuria for women with recurrent symptomatic urinary tract infections receiving prophylaxis

Abstract

A significant proportion of women develop a recurrence following an initial urinary tract infection (UTI). In women with recurrent UTI, the predictive value of asymptomatic bacteriuria (ASB) for the development of a subsequent UTI has not yet been established and it is not known whether information from an asymptomatic sample is useful in guiding antimicrobial therapy. To address these questions, we used data that originated from the 'Non-antibiotic prophylaxis for recurrent urinary tract infections' (NAPRUTI) study: two randomized controlled trials on the prevention of recurrent UTI in non-hospitalized premenopausal and postmenopausal women (n=445). During 15months of follow-up, no difference was observed in the time to a subsequent UTI between women with and without ASB at baseline (hazard ratio: 1.07, 95% CI 0.80-1.42). The antimicrobial susceptibility and pulsed-field gel-electrophoresis (PFGE) pattern of 50 Escherichia coli strains causing a UTI were compared with those of the ASB strain isolated 1month previously. The predictive values of the susceptibility pattern of the ASB strain, based on resistance prevalence at baseline, were ≥76%, except in the case of nitrofurantoin- and amoxicillin-clavulanic acid-resistance. Asymptomatic and symptomatic isolates had similar PFGE patterns in 70% (35/50) of the patients. In the present study among women with recurrent UTI receiving prophylaxis, ASB was not predictive for the development of a UTI. However, the susceptibility pattern of E. coli strains isolated in the month before a symptomatic E. coli UTI can be used to make informed choices for empirical antibiotic treatment in this patient population.

Determinants of Antimicrobial Resistance in Escherichia coli Strains Isolated from Faeces and Urine of Women with Recurrent Urinary Tract Infections

“…However, we have recently shown that asymptomatic E. coli strains are predictive for strains that cause a symptomatic E. coli UTI in women with rUTI [15].…”

Non-Antibiotic Prophylaxis for Urinary Tract Infections

“…However, the susceptibility and pulsed-field gel electrophoresis pattern of E. coli strains isolated from urine in the month before a symptomatic E. coli UTI were similar in about three quarter of patients. These findings suggest an intracellular bacterial reservoir could possibly serve as a nidus for recurrence in same-strain UTIs in women with recurrent UTIs [ 14 ].…”

Recurrent urinary tract infections in healthy and nonpregnant women

“…In six studies of women experiencing RUTI following a primary infection, the rate reinfection by primary strain varied from 47% to 81%. 40–45 Although five of the six studies propose a slightly higher rate of reinfection by QIR recurrence (> 50% reinfection by primary strain), 41–45 the aggregated results suggest that both ascending reinfection and QIR recurrence are significant causes of RUTI in women (Table 1). …”