CTX-M-15-producing H30 ST131 Escherichia coli contributes to carbapenem use for E. coli bloodstream infections in the United States
Recommended Citation
Mackow NA, Shao W, Ge L, Komarow L, Boutzoukas AE, Jiang J, Chen L, Herc E, Doi Y, Arias CA, Albin O, Saade E, Miller LG, Jacob JT, Satlin MJ, Krsak M, Huskins W, Dhar S, Shelburne SA, Hill C, Greenwood-Quaintance K, Schmidt-Malan S, Patel R, Fowler VG, Tamma P, Kreiswirth BN, van Duin D. CTX-M-15-producing H30 ST131 Escherichia coli contributes to carbapenem use for E. coli bloodstream infections in the United States. Open Forum Infect Dis 2025; 12(Supplement 1):S602-S603.
Document Type
Conference Proceeding
Publication Date
1-29-2025
Publication Title
Open Forum Infect Dis
Abstract
Background. Drug-resistant E. coli is a leading cause of antimicrobial resistance-associated deaths globally. Specifically, resistance to ceftriaxone (CRO-R) is increasing in E. coli. High-risk clonal group ST131 and its pandemic H30 subclone are of high concern yet studies characterizing these infections are limited. We evaluated baseline characteristics and clinical outcomes associated with H30 ST131, non-H30 ST131 and non-ST131 E. coli bloodstream infections (BSI). Methods. Patients with monomicrobial carbapenem-Susceptible E. coli BSI that were matched 1:1 by study site (CRO-R and CRO-Susceptible community-acquired and hospital onset cases) were prospectively enrolled from 14 United States hospitals between November 12, 2020 to April 28, 2021 in the multicenter Study of Highly Resistant E. coli (SHREC). Isolates underwent whole genome sequencing. The primary outcome was a 30-day Desirability of Outcome Ranking (DOOR) after index culture including clinical response to treatment and all-cause mortality Results. There were 92 (33%) H30 ST131, 29 (10%) non-H30 ST131, and 161 (57%) non-ST131 isolates in 282 E. coli BSI (Table 1). Most ceftriaxone resistance was conferred by CTX-M-15 produced by H30 ST131 isolates (Figure 1, Table 1). H30 ST131 BSI patients were older (median age [IQR] 70.5 [63,76] vs. 67 [56,77] vs 65 [51,74] years, p = 0.017), had higher Charlson comorbidity indices (3 [2,5] vs. 2 [1,4] vs. 2 [1,4], p=0.009), and were more often admitted from long-term care facilities (18/92 [20%] vs. 3/29 [10%] vs. 7/161 [4%], p = 0.003) compared to non-H30 ST131 and non-ST131 BSI patients. Among H30 ST131 isolates, high rates of antibiotic resistance were observed to cephalosporins and fluoroquinolones, resulting in significantly more carbapenem use compared with non-H30 ST131 and non-ST131 isolates (75/92 [82%] vs. 14/29 [48%] vs. 50/161 [31%], p < 0.001) (Figure 2). 30-day DOOR and hospital length of stay did not differ between groups (Table 2). Conclusion. Compared with non-H30 ST131 and non-ST131 E. coli BSI, H30 ST131 E. coli BSI have a unique epidemiology with more healthcare exposures, comorbidities and antibiotic resistance and are more likely to be treated with carbapenems, though no significant difference in clinical outcomes was observed.
Volume
12
Issue
Supplement 1
First Page
S602
Last Page
S603
