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Comparison of Disk Diffusion, E-Test, and Broth Microdilution Methods for Testing In Vitro Activity of Cefiderocol Against Carbapenem-Resistant Acinetobacter Baumannii
Kolesnik-Goldmann, N.; Seth-Smith, H.M.B.; Haldimann, K.; Imkamp, F.; Roloff, T.; Zbinden, R.; Hobbie, S.N.; Egli, A.; Mancini, S. Comparison of Disk Diffusion, E-Test, and Broth Microdilution Methods for Testing In Vitro Activity of Cefiderocol in Acinetobacter baumannii. Antibiotics2023, 12, 1212.
Kolesnik-Goldmann, N.; Seth-Smith, H.M.B.; Haldimann, K.; Imkamp, F.; Roloff, T.; Zbinden, R.; Hobbie, S.N.; Egli, A.; Mancini, S. Comparison of Disk Diffusion, E-Test, and Broth Microdilution Methods for Testing In Vitro Activity of Cefiderocol in Acinetobacter baumannii. Antibiotics 2023, 12, 1212.
Kolesnik-Goldmann, N.; Seth-Smith, H.M.B.; Haldimann, K.; Imkamp, F.; Roloff, T.; Zbinden, R.; Hobbie, S.N.; Egli, A.; Mancini, S. Comparison of Disk Diffusion, E-Test, and Broth Microdilution Methods for Testing In Vitro Activity of Cefiderocol in Acinetobacter baumannii. Antibiotics2023, 12, 1212.
Kolesnik-Goldmann, N.; Seth-Smith, H.M.B.; Haldimann, K.; Imkamp, F.; Roloff, T.; Zbinden, R.; Hobbie, S.N.; Egli, A.; Mancini, S. Comparison of Disk Diffusion, E-Test, and Broth Microdilution Methods for Testing In Vitro Activity of Cefiderocol in Acinetobacter baumannii. Antibiotics 2023, 12, 1212.
Abstract
The reference method for cefiderocol antimicrobial susceptibility testing is broth microdilution (BMD) with iron-depleted-Mueller-Hinton (ID-MH) medium, whereas breakpoints recommended for disk diffusion (DD) are based on MH-agar plates. We aimed to compare the performance of the commercial BMD tests ComASP (Liofilchem) and UMIC (Bruker), DD and E-test using MH- and ID-MH-agar plates with the reference BMD method using 100 carbapenem-resistant-A. baumannii isolates. Standard BMD was performed according to the EUCAST guidelines, DD and E-test were carried out using two commercial MH-agar plates (bioMérieux and Liofilchem) and an in-house ID-MH-agar plate, while ComASP and UMIC were performed according to the manufacturer’s guidelines.
DD performed with the ID-MH-agar plates led to a higher categorical agreement (CA, 95.1%) with standard BMD and fewer categorization errors compared to the commercial MH-agar plates (CA bioMérieux 91.1%, Liofilchem 89.2%). E-test on ID-MH-agar plates exhibited a significantly higher essential agreement (EA, 75%) with standard BMD compared to the two MH-agar plates (EA bioMérieux 57%, Liofilchem 44%), and showed a higher performance in detecting high-level resistance than ComASP and UMIC (mean log2 difference with standard BMD for resistant isolates of 0.5, 2.83 and 2.08, respectively).
In conclusion, DD and E-test on ID-MH-agar plates exhibit a higher diagnostic performance than on MH-agar plates and the commercial BMD methods. Therefore, we recommend using ID-MH-agar plates for cefiderocol susceptibility testing of A. baumannii.
Keywords
cefiderocol; A. baumannii; disk diffusion; broth microdilution; E-test; iron-depletion
Subject
Biology and Life Sciences, Biology and Biotechnology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
