In vitro antibacterial activities of cefiderocol against Gram-negative clinical strains isolated from China in 2020

Objectives: Cefiderocol (CFDC) is a parenteral siderophore cephalosporin that is active against Gram-negative bacteria, including carbapenem-resistant isolates. We report the in vitro activity of CFDC and other antibiotics against 1738 clinical isolates of Gram-negative bacilli (GNB) provided by five medical centres in five provinces of China in 2020Methods: Antibiotic susceptibility testing was performed using the Clinical and Laboratory Standards In-stitute broth microdilution method.Results: Against Pseudomonas aeruginosa and Acinetobacter Spp., the CFDC concentration inhibiting the growth of 90% of the isolates (MIC90) (0.5 mu g/mL) was identical and did not change by the carbapenem resistance phenotype. The susceptibility rate of P. aeruginosa and Acinetobacter Spp. to CFDC was high ( > 98%) and was similar against isolates with and without meropenem resistance. The MIC of CFDC for all Stenotrophomonas maltophilia isolates (20 isolates) was <= 1 mu g/mL and the MIC90 was 0.12 mu g/mL. Con-siderable differences were noted in the susceptibility to CFDC between all tested Enterobacterales isolates and meropenem-non-susceptible Enterobacterales isolates. The MIC90 of CFDC was 1 mu g/mL for all tested Enterobacterales isolates and 8 mu g/mL for meropenem-non-susceptible Enterobacterales isolates. Conclusions: CFDC demonstrated potent in vitro activity against a recent collection of clinical isolates, including meropenem-non-susceptible isolates, obtained from medical centres in mainland China.(c) 2022 The Author(s). Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy.This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )