Abstract
Background
Escherichia coli sequence type (ST) 131-
H30 is a globally important pathogen implicated in rising rates of multidrug resistance among
E. coli causing extraintestinal infections. Previous studies have focused on adults, leaving the epidemiology of
H30 among children undefined.
Methods
We used clinical data and isolates from a case-control study of extended-spectrum cephalosporin-resistant
E. coli conducted at 4 US children's hospitals to estimate the burden and identify host correlates of infection with
H30. H30 isolates were identified using 2-locus genotyping; host correlates were examined using log-binomial regression models stratified by extended-spectrum cephalosporin resistance status.
Results
A total of 339 extended-spectrum cephalosporin-resistant and 1008 extended-spectrum cephalosporin-susceptible
E. coli isolates were available for analyses. The estimated period prevalence of
H30 was 5.3% among all extraintestinal
E. coli isolates (95% confidence interval [CI], 4.6%–7.1%);
H30 made up 43.3% (81/187) of extended-spectrum β-lactamase (ESBL)–producing isolates in this study. Host correlates of infection with
H30 differed by extended-spectrum cephalosporin resistance status: Among resistant isolates, age ≤5 years was positively associated with
H30 infection (relative risk [RR], 1.83 [95% CI, 1.19–2.83]); among susceptible isolates, age ≤5 years was negatively associated with
H30 (RR, 0.48 [95% CI, .27–.87]), while presence of an underlying medical condition was positively associated (RR, 4.49 [95% CI, 2.43–8.31]).
Conclusions
ST131-
H30 is less common among extraintestinal
E. coli collected from children compared to reported estimates among adults, possibly reflecting infrequent fluoroquinolone use in pediatrics; however, it is similarly dominant among ESBL-producing isolates. The
H30 subclone appears to disproportionately affect young children relative to other extended-spectrum cephalosporin-resistant
E. coli.