Escherichia coli ST131, with its multidrug-resistance-associated H30R1 and H30Rx clonal subsets within the H30R subclone, causes most antimicrobial-resistant E. coli infections. The activity of ceftazidime-avibactam (CZA) against ST131 strains is undefined. We determined CZA MICs for 595 E. coli clinical isolates from 24 Veterans Affairs Medical Centers (2010-2011). Resistance status and MICs were compared with study resistance category (fluoroquinolone-susceptible, fluoroquinolone-resistant, and extended-spectrum beta-lactamase (ESBL)-producing); ST131, H30R1, and H30Rx status; bla-like genotype; and MICs for piperacillin-tazobactam, levofloxacin, gentamicin, ceftazidime, and meropenem. Proportion resistant ranged from zero (CZA, meropenem) to 61% (levofloxacin). MICs generally increased by resistance category (from fluoroquinolone-susceptible through fluoroquinolone-resistant to ESBL), clonal subgroup (from non-ST131-H30 through H30R1 to H30Rx), and bla-like status. CZA MICs were slightly but significantly greater in association with resistance (or elevated MICs) to each comparator yet remained in the susceptible range. CZA was reliably active and outperformed noncarbapenem comparators, so it should prove useful as a carbapenem-sparing alternative.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.diagmicrobio.2020.115034 | DOI Listing |
Am J Infect Control
April 2023
University of Minnesota College of Pharmacy, Minneapolis, MN, USA. Electronic address:
Microbiol Spectr
June 2022
Minneapolis VA Health Care System, Minneapolis, Minnesota, USA.
J Antimicrob Chemother
July 2021
Minneapolis VA Health Care System, Minneapolis, MN, USA.
Background: Emerging carbapenem resistance in Escherichia coli, including sequence type 131 (ST131), threatens therapeutic efficacy. Plazomicin (PLZ), a semisynthetic aminoglycoside approved by the FDA in 2018, overcomes the most common aminoglycoside resistance mechanisms and maintains activity against many carbapenem-intermediate or -resistant (CIR) E. coli strains.
View Article and Find Full Text PDFEur J Clin Microbiol Infect Dis
October 2021
Infectious Diseases (111F), VA Medical Center, Minneapolis VA Health Care System, 1 Veterans Drive, Minneapolis, MN, 55417, USA.
Extended-spectrum cephalosporin-resistant Escherichia coli (ESCREC) are a growing threat. Leading ESCREC lineages include sequence type ST131, especially its (bla-associated) H30Rx subclone and (bla-associated) C1-M27 subset within the H30R1 subclone. The comparative activity against such strains of alternative antimicrobial agents, including the recently developed aminoglycoside plazomicin, is undefined, so was investigated here.
View Article and Find Full Text PDFDiagn Microbiol Infect Dis
May 2021
University of Minnesota, Minneapolis, MN, USA. Electronic address:
Extended-spectrum cephalosporin-resistant Escherichia coli (ESCREC) are a growing threat. Leading ESCREC lineages include sequence type ST131, especially its (bla-associated) H30Rx subclone and (bla-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 (bla; group 1 and 9 variants), and coresistance.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!