Changes in antimicrobial resistance and demographics of UTIs in pediatric patients in a single institution over a 6-year period.

PURPOSE: To determine changes in antimicrobial resistance and demographics of UTIs in pediatric patients in a single institution over a 6-year period.

MATERIALS AND METHODS: The current study examined outpatient urinary isolates from patients aged <18 years. A retrospective cross-sectional analysis of bacteria isolated from children with UTI was performed between 2009 and 2014. The most common bacterial pathogens were determined in the following four age groups: <2 years; 2-5 years; 6-12 years; and 13-17 years. The study analyzed the prevalence and antibiotic resistance patterns for the six most common uropathogens: Escherichia coli, Proteus, Klebsiella, Enterobacter, Pseudomonas and Enterococcus (Summary table). The antibiotic resistance pattern for UTI during 2009-2014 was also examined.

RESULTS: A total of 6515 urinary cultures was examined. The majority of these isolates were from female patients (66.8%). E. coli was the most common uropathogen overall, but the prevalence of E. coli was higher among females (79.5%) than males (54.9%). The biggest percentage of isolates in males was from children aged <2 years (46.1%). Conversely, the majority of isolates in females were from children aged >6 years (46.8%). Results of antimicrobial resistance for E. coli were the highest for ampicillin (70%) and lowest for meropenem (0.19%). Comparing the hospital network data from 2009 to 2014, E. coli resistance increased for ampicillin (from 47.1% to 89%), trimethoprim-sulfamethoxazole (TMP-SMX) (from 44.8% to 56%) and nitrofurantoin (from 5.3% to 15.1%). In contrast, cephalosporins have maintained low antibiotic resistance.

CONCLUSION: UTI in females was nearly twice as common than in males. E. coli remained the most common pediatric uropathogen. Although widely used in other tract infections, ampicillin was a poor empiric choice for pediatric UTIs. Cephalosporins were appropriate alternatives given their low resistance rates. A successful empirical treatment protocol should be based on local epidemiology and susceptibility rates.