Antimicrobial susceptibility patterns of Escherichia coli in children and adults with urinary tract infections

Abstract

INTRODUCTION. Urinary tract infections (UTIs) are common pathology in children and adults that is caused mainly by Gram-negative bacteria among which Escherichia coli plays an outstanding role. UTIs treatment demands empiric antibiotic therapy and knowing of antimicrobial local susceptibility and resistance patterns is crucial for making a decision about an agent for the first line therapy. The AIM of this study was to evaluate the local susceptibility patterns of uropathogenic E. coli isolates to antibiotics in patients with UTIs. MATERIALS AND METHODS. A total of 129 E. coli isolates obtained from 44 children (under the age of 18) and 85 adults with community-acquired UTIs were included in this retrospective study during January and December 2017. Antimicrobial susceptibility testing to17 antimicrobials was performed using disc diffusion method on Mueller-Hinton agar. Statistical analyses were performed using Microsoft Excel 2010 and Statistica 10 software. 95% confidence intervals (CI) for proportions were determined using the Agresti-Coull method. P-values were obtained using two-tailed Fisher’s exact test. The difference was considered to be statistically significant if p<0.05. RESULTS. E. coli was highly susceptible to levofloxacin and gatifloxacin (93.18% [95% CI 81.11-98.32%] for each) with the lowest susceptibility to amoxicillin/clavulanic acid (2.27%, 95% CI 0.00-12.89%) in children. Susceptibility to the tested cephalosporins ranged from 34.09% (cefuroxime, 95% CI 21.82-48.92%) to 65.91% (cefepime, 95% CI 51.08-78.18%). In adults the highest susceptibility was to gatifloxacin and ceftriaxone (80.00% [95% CI 70.19-87.22%] for both) and the lowest one to amoxicillin/clavulanic acid (2.35%, 95% CI 0.14-8.68%). CONCLUSIONS. Aminopenicillins are not suitable for UTIs treatment unless susceptibility is confirmed by testing. Fluoroquinolones cannot be used for the empirical treatment either of complicated or uncomplicated pyelonephritis in adults. Cefotaxime and ceftriaxone can be recommended for initial treatment of complicated UTIs in adults. The efficacy of cephalosporins in children is doubtful due to high local resistance rates.