Cefiderocol susceptibility rates in carbapenem-resistant Gram-negative bacteria in a comparative, multicenter surveillance study in China.
BACKGROUND: Cefiderocol is a siderophore cephalosporin with potent, broad spectrum of activity against carbapenem-resistant (CR) Gram-negative bacteria. The objective of this surveillance study was to assess cefiderocol susceptibility in molecularly characterized CR Gram-negative pathogens collected from hospitalized patients across China. METHODS: Susceptibility testing was performed by the broth microdilution method according to Clinical and Laboratory Standards Institute guidelines, using pre-prepared frozen 96-well microtiter Thermo Fisher plates. Susceptibilities to cefiderocol and most comparators were determined by Clinical and Laboratory Standards Institute breakpoints, to tigecycline by US Food and Drug Administration breakpoints, and to colistin by European Committee on Antimicrobial Susceptibility Testing criteria. Carbapenemases were identified by whole-genome sequencing and polymerase chain reaction. RESULTS: Of 149 CR Klebsiella pneumoniae, 95.3% were susceptible to cefiderocol (OXA-48-positive 100% [n = 15]; IMP-positive 100% [n = 9]; KPC-positive 95.4% [n = 108]; NDM-positive 88.2% [n = 17]) and against 103 NDM-positive CR Escherichia coli, cefiderocol susceptibility was 45.6%. Among comparator antibiotics, ceftazidime-avibactam was only active against K. pneumoniae carbapenemase-positive and OXA-48-positive K. pneumoniae isolates. Susceptibilities to tigecycline and colistin were between 22.2% and 97.1% and between 88.2% and 100% across CR Enterobacterales with different carbapenemases, respectively. High cefiderocol susceptibility rates were found for CR Pseudomonas aeruginosa (98.4%), CR Acinetobacter baumannii (99.6%), and Stenotrophomonas maltophilia (99.6%). Among comparator antibiotics, only colistin showed high activity against CR P. aeruginosa (99.2%) and CR A. baumannii (99.2%). CONCLUSIONS: Cefiderocol susceptibility rates were ≥88% against a collection of carbapenemase-positive CR Gram-negative isolates, except for lower susceptibility in NDM-positive CR E. coli isolates. Continuous monitoring of cefiderocol susceptibility is warranted.