Community Origins and Regional Differences Highlight Risk of Plasmid-mediated Fluoroquinolone Resistant Enterobacteriaceae Infections in Children

Pediatr Infect Dis J. 2019 Jun;38(6):595-599. doi: 10.1097/INF.0000000000002205.


Background: Fluoroquinolones are uncommonly prescribed in children, yet pediatric multidrug resistant (MDR) enterobacteriaceae (Ent) infections often reveal fluoroquinolone resistance (FQR). We sought to define the molecular epidemiology of FQR and MDR-Ent in children.

Methods: A case-control analysis of children with MDR-Ent infections at 3 Chicago hospitals was performed. Cases were children with third-generation cephalosporin-resistant and/or carbapenem-resistant Ent infections. Polymerase chain reaction and DNA analysis assessed bla and plasmid-mediated FQR (PMFQR) genes. Controls were children with third-generation cephalosporin, fluoroquinolone, and carbapenem-susceptible Ent infections matched by age, source and hospital. We assessed clinical-epidemiologic predictors of PMFQR Ent infection.

Results: Of 169 third-generation cephalosporin-resistant and/or carbapenem-resistant Ent isolates from children (median age, 4.8 years), 85 were FQR; 56 (66%) contained PMFQR genes. The predominant organism was Escherichia coli, and most common bla gene blaCTX-M-1 group. In FQR isolates, PMFQR gene mutations included aac6'1bcr, oqxA/B, qepA and qnrA/B/D/S in 83%, 15%, 13% and 11% of isolates, respectively. FQR E. coli was often associated with phylogroup B2, ST43/ST131. On multivariable analysis, PMFQR Ent infections occurred mostly in outpatients (odds ratio, 33.1) of non-black-white-Hispanic race (odds ratio, 6.5). Residents of Southwest Chicago were >5 times more likely to have PMFQR Ent infections than those in the reference region, while residence in Central Chicago was associated with a 97% decreased risk. Other demographic, comorbidity, invasive-device, antibiotic use or healthcare differences were not found.

Conclusions: The strong association of infection with MDR organisms showing FQR with patient residence rather than with traditional risk factors suggests that the community environment is a major contributor to spread of these pathogens in children.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Anti-Bacterial Agents / pharmacology*
  • Case-Control Studies
  • Chicago / epidemiology
  • Child
  • Child, Preschool
  • Community-Acquired Infections / epidemiology
  • Community-Acquired Infections / microbiology
  • DNA, Bacterial / genetics
  • Drug Resistance, Multiple, Bacterial
  • Enterobacteriaceae / drug effects*
  • Enterobacteriaceae / genetics*
  • Enterobacteriaceae Infections / drug therapy
  • Enterobacteriaceae Infections / epidemiology*
  • Fluoroquinolones / pharmacology*
  • Humans
  • Infant
  • Infant, Newborn
  • Microbial Sensitivity Tests
  • Plasmids / genetics*
  • Risk Factors
  • Tertiary Care Centers
  • Young Adult


  • Anti-Bacterial Agents
  • DNA, Bacterial
  • Fluoroquinolones