Miles-Jay A, et al. - Researchers here aimed at assessing the epidemiology and antimicrobial resistance characteristics of the ST131-H30 subclone among extraintestinal Escherichia coli collected from US children. Compared to reported estimates among adults, ST131-H30 seemed less common among extraintestinal E. coli collected from children, possibly reflecting infrequent fluoroquinolone use in pediatrics; however, it was similarly dominant among ESBL-producing isolates. The H30 subclone appeared to disproportionately affect young children relative to other extended-spectrum cephalosporin-resistant E. coli.

Methods

• For this study, researchers used clinical data and isolates from a case-control study of extended-spectrum cephalosporin-resistant E. coli performed at four US children’s hospitals.
• They estimated the burden and identified host correlates of infection with H30.
• Using two-locus genotyping, H30 isolates were identified; host correlates were assessed using log-binomial regression models stratified by extended-spectrum cephalosporin resistance status.

Results

• For analysis, 339 extended-spectrum cephalosporin-resistant and 1008 extended-spectrum cephalosporin-susceptible E. coli isolates were available.
• Among all extraintestinal E. coli isolates, the estimated period prevalence of H30 was 5.3% (95% confidence interval [CI] 4.6%-7.1%); H30made up 43.3% (81/187) of 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 0.27-0.87), while presence of an underlying medical condition was positively associated (RR 4.49, 95% CI 2.43-8.31).