Escherichia coli ST131 Drives Carbapenem Use for E. Coli Bloodstream Infections.

BACKGROUND: Ceftriaxone-resistant Escherichia coli infections are increasingly common, partially due to the emergence of E. coli sequence type 131 (ST131) including its subclade C2/H30Rx that produce extended-spectrum β-lactamases (ESBL). METHODS: A prospective cohort including 14 US sites, which enrolled monomicrobial ceftriaxone-resistant and susceptible E. coli BSI cases in a 1:1 ratio, was used to compare ST131 versus non-ST131 E. coli BSI, with specific attention to E. coli ST131 C2/H30Rx. Desirability of outcome ranking (DOOR) was determined at 30 days after infection onset. RESULTS: This analysis included 282 patients with E. coli BSI; 43% (121/282) were E. coli ST131, and 23% (66/282) belonged to the C2/H30Rx subclade. Resistance to ceftriaxone was present in 79% (96/121) ST131, 86% (57/66) E. coli ST131 C2/H30Rx, and 27% (43/161) E. coli non-ST131. Compared to patients with non-ST131 E. coli BSI, patients with ST131 BSI were older (median 70 years, [Q1 62, Q3 76] years vs. 65 years, [51, 74]; p = 0.005) and more often admitted from long-term care facilities (21/121 [17%] vs 7/161 [4%], p <0.001). Overall and empiric carbapenem use was more frequent in the treatment of patients with ST131 BSI compared with non-ST131 BSI (overall 89/121 [74%] vs 50/161 [31%]; empiric: 58/121 [48%] vs. 31/161 [19%], p <0.001). DOOR outcomes were similar between groups. CONCLUSIONS: Most ceftriaxone-resistant E. coli from US patients with E. coli BSI belong to ST131, particularly E. coli ST131 C2/H30Rx, serving as an important driver of carbapenem use.

Duke Scholars

Author Angelique Boutzoukas Pediatrics, Infectious Diseases

Author Vance Garrison Fowler Jr. Medicine, Infectious Diseases