Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Oct;66(4):107553.
doi: 10.1016/j.ijantimicag.2025.107553. Epub 2025 Jun 18.

Susceptibility to new antibiotics and genetic characterisation of carbapenemase-producing Enterobacterales: low activity of cefiderocol against NDM-producing isolates

Lisa Faxén  1 , Vilhelm Müller  2 , Margarita Chatzopoulou  3 , Oskar Karlsson Lindsjö  2 , Pernilla Lagerbäck  3 , Karin Westmo  2 , Anna Åkerlund  4 , Thomas Tängdén  3 , Inga Fröding  5
Affiliations
Free article

Susceptibility to new antibiotics and genetic characterisation of carbapenemase-producing Enterobacterales: low activity of cefiderocol against NDM-producing isolates

Lisa Faxén et al. Int J Antimicrob Agents. 2025 Oct.
Free article

Abstract

Objectives: Carbapenemase-producing Enterobacterales (CPEs) pose a serious medical threat. In recent years, several new antibiotics targeting carbapenem-resistant Gram-negative bacteria have been introduced, including cefiderocol, ceftazidime-avibactam, imipenem-relebactam and meropenem-vaborbactam. However, no systematic monitoring of susceptibility levels is routinely performed, which challenges rational use and the effectiveness of the new antibiotics due to the risk of rapid emergence of resistance. The objective of this study was to assess the susceptibility of new antibiotics targeting carbapenem-resistant Gram-negative bacteria against CPEs in Sweden.

Methods: All CPE isolates collected through Sweden's national microbial surveillance programme in 2022 were included. Susceptibility testing for the new antibiotics and other agents relevant to CPEs was performed with broth microdilution for all drugs except for cefiderocol and fosfomycin, for which EUCAST disk diffusion was applied. Whole-genome sequencing was performed for genetic characterisation.

Results: In total, 286 CPEs were included in the study. Susceptibility rates were high for ceftazidime-avibactam in OXA-48-like producing isolates (n = 116, >95%) and for ceftazidime-avibactam and meropenem-vaborbactam against KPC/IMI-producing isolates (n = 22, ≥90%). In contrast, susceptibility to cefiderocol was low in MBL-producing Enterobacterales according to disk diffusion: 0% (0/76) of Escherichia coli and 6% (3/54) of Klebsiella pneumoniae were classified susceptible, and 93% (71/76) and 39% (21/54), respectively, were resistant. The presence of blaNDM-5 was associated with the highest level of resistance.

Conclusions: Considerable variability was observed in the susceptibility rates of the newly introduced antibiotics against CPEs collected in Sweden. Continued surveillance is warranted to guide rational use of these new last-resort antibiotics.

Keywords: Broth microdilution; Carbapenemases; Disk diffusion; Escherichia coli; Klebsiella pneumoniae; MIC; Multidrug resistance.

PubMed Disclaimer

MeSH terms