Extended-spectrum β-lactamase-producing Escherichia coli bacteremia: Comparison of pediatric and adult populations

Background/Purpose: The prevalence of extended-spectrum beta-lactamase (ESBL)producing Escherichia coli is increasing worldwide. This study investigated the clinical features and bacteriology of pediatric patients with ESBL-producing E. coli bacteremia and compared their characteristics with those of adult patients. Methods: Clinical and laboratory data from all of the 41 patients aged <= 18 years diagnosed with E. coli bacteremia were collected over 5 years. Patients aged >18 years diagnosed with E. coli bacteremia, matched 1:1 for calendar time, were enrolled as the adult group. All E. coli isolates were tested for their bIaCTX-M group and sequence type 131 (ST131). A novel seven-single nucleotide polymorphism-based clonotyping test was applied to detect the septatypes of each isolate. Results: In the adult group, patients with ESBL-producing E. coli bacteremia had more previous hospitalizations and antimicrobial agent use than did those with non-ESBL-producing E. coli bacteremia, but these differences were not found in pediatric group. In the pediatric group, the proportion of isolates producing CTX-M group 9 was higher than that in the adult group (85.7% vs. 42.9%; p < 0.05). Among both groups, there were more E. coli ST131 in ESBL isolates in than there were non-ESBL isolates. The distribution of septatypes was more homogenous in ESBL-producing E. coli among the pediatric patients than among the adult patients. Conclusion: ST131 was the major clone causing E. coli bacteremia in both pediatric and adult populations. The pediatric population demonstrated a higher number of isolates producing CTX-M group 9 with more homogenous septatypes compared with the adult population. Copyright (C) 2017, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC.