FDA-cleared susceptibility testing is available for cefiderocol through 2 different methods: (1) disk diffusion, and (2) broth microdilution using using iron-depleted cation-adjusted Mueller Hinton Broth (ID-CAMHB).1 Reference laboratory testing is also available.
Cefiderocol susceptibility testing by disk diffusion is performed on normal agar (and not iron-depleted agar).2
Susceptibility testing with broth microdilution requires ID-CAMHB, given cefiderocol’s unique mechanism of bacterial cell entry.3
Abbreviations: FDA=US Food and Drug Administration; ID-CAMHB=iron-depleted cation-adjusted Mueller Hinton Broth.
References:
- US FDA. Antibacterial Susceptibility Test Interpretive Criteria. 2024. https://www.fda.gov/drugs/development-resources/cefiderocol-injection. Accessed June 15, 2025.
- DeJonge BLM, et al. ASM Microbe 2025. June 19–23, 2025. Los Angeles, CA. Poster 2011.
- CLSI. Performance Standards for Antimicrobial Susceptibility Testing, 35th Edition. M100. 2025. Accessed February 3, 2025.