Document Type


Publication Date



PMCID: PMC5404513 DOI: 10.1128/AAC.02656-16


The objective of this study was to assess the association between previous antibiotic use, particularly long-term prophylaxis, and the occurrence of subsequent resistant infections in children with index infections due to extended-spectrum-cephalosporin-resistant Enterobacteriaceae We also investigated the concordance of the index and subsequent isolates. Extended-spectrum-cephalosporin-resistant Escherichia coli and Klebsiella spp. isolated from normally sterile sites of patients aged species, resistance determinants, and fumC-fimH (E. coli) or tonB (Klebsiella pneumoniae) type were identical to those of the index isolate. In total, 323 patients had 396 resistant isolates; 45 (14%) patients had ≥1 subsequent resistant infection, totaling 73 subsequent resistant isolates. The median time between the index and first subsequent infections was 123 (interquartile range, 43 to 225) days. In multivariable Cox proportional hazards analyses, patients were 2.07 times as likely to have a subsequent resistant infection (95% confidence interval, 1.11 to 3.87) if they received prophylaxis in the 30 days prior to the index infection. In 26 (58%) patients, all subsequent isolates were concordant with their index isolate, and 7 (16%) additional patients had at least 1 concordant subsequent isolate. In 12 of 17 (71%) patients with E. coli sequence type 131 (ST131)-associated type 40-30, all subsequent isolates were concordant. Subsequent extended-spectrum-cephalosporin-resistant infections are relatively frequent and are most commonly due to bacterial strains concordant with the index isolate. Further study is needed to assess the role prophylaxis plays in these resistant infections.

Journal Title

Antimicrobial agents and chemotherapy





MeSH Keywords

Adhesins, Escherichia coli; Anti-Bacterial Agents; Antibiotic Prophylaxis; Bacterial Outer Membrane Proteins; Bacterial Proteins; Cephalosporin Resistance; Cephalosporins; Child; Child, Preschool; Escherichia coli; Escherichia coli Infections; Female; Fimbriae Proteins; Humans; Infant; Klebsiella Infections; Klebsiella pneumoniae; Male; Microbial Sensitivity Tests; beta-Lactam Resistance; beta-Lactamases


antibiotic resistance; pediatric infectious disease