In Vitro Activity of Cefiderocol, a Novel Siderophore Cephalosporin, against Gram-Negative Bacilli Isolated from Patients in Canadian Intensive Care Units

Abstract The in vitro activity of cefiderocol was evaluated against Gram-negative bacilli isolated from patients in Canadian intensive care units from 2015 to 2017 using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method and interpretive criteria. All 800 isolates of Gram-negative bacilli tested were susceptible to cefiderocol (MIC ≤4 μg/ml), including isolates of ESBL-producing (n=40), AmpC-producing (n=6), and carbapenem-nonsusceptible (n=21) Enterobacterales, carbapenem-nonsusceptible (n=54) and multidrug-resistant (n=29) Pseudomonas aeruginosa, Stenotrophomonas maltophilia (n=66), and Acinetobacter baumannii (n=11).