Extended-spectrum cephalosporin-resistant Escherichia coli (ESCREC) are a growing threat. Leading ESCREC lineages include sequence type ST131, especially its (blaCTX-M-15-associated) H30Rx subclone and (blaCTX-M-27-associated) C1-M27 subset within the H30R1 subclone. We assessed cefiderocol, ceftazidime-avibactam, eravacycline, and 11 comparators for activity against 216 well-characterized ESCREC isolates (Minnesota, 2012–2017), then compared broth microdilution MICs with phylogenetic and clonal background, beta-lactamase genotype (blaCTX-M; group 1 and 9 variants), and coresistance. Percent susceptible was >95% (cefiderocol, ceftazidime-avibactam, eravacycline, carbapenems, amikacin, piperacillin-tazobactam, tigecycline), 64% to 75% (gentamicin, minocycline), or <40% (ceftazidime, levofloxacin, colistin). MICs varied significantly by multiple bacterial characteristics, in agent-specific patterns. The least-susceptible ST131 subset was the non-C1-M27 fraction within H30R1. Cefiderocol, ceftazidime-avibactam, and eravacycline MICs tended to be higher among isolates resistant (vs. susceptible) to diverse comparators. Thus, cefiderocol, ceftazidime-avibactam, and eravacycline are promising carbapenem-sparing alternatives for treating ESCREC infections, and their strength of activity varies in relation to diverse bacterial characteristics.
|Original language||English (US)|
|Journal||Diagnostic Microbiology and Infectious Disease|
|State||Published - May 2021|
Bibliographical noteFunding Information:
This work was supported in part by research grants from Allergan, Shionogi & Co. Ltd., and Tetraphase Pharmaceuticals and by the Office of Research Development, Department of Veterans Affairs , grant # 2I01CX000920-04 (JRJ). The funders had no control over the content of the report or the decision to publish. The opinions expressed are those of the authors and not necessarily those of the authors’ institutions or the Department of Veterans Affairs.
- antimicrobial therapy
- bla genotype
- E. coli ST131 H30
- extended-spectrum cephalosporin-resistant
- minimum inhibitory concentration
- multidrug resistance
PubMed: MeSH publication types
- Journal Article