1. Azole and Amphotericin B MIC Values against Aspergillus fumigatus: High Agreement between Spectrophotometric and Visual Readings Using the EUCAST EDef 9.3.2 Procedure
- Author
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Serrano-Lobo, J., Gómez, A., Sánchez-Yebra, W., Fajardo, M., Lorenzo, B., Sánchez-Reus, F., Vidal, I., Fernández-Torres, M., Sánchez-Romero, I., de Alegría-Puig, C.R., del Pozo, J.L., Muñoz, P., Escribano, P., Guinea, J., Sánchez-Gómez, J., Lozano, I., Marfil, E., de la Rosa, M.M., García, R.T., Cobo, F., Castro, C., López, C., Rezusta, A., Peláez, T., Castelló-Abietar, C., Cos-Tales, I., Serra, J.L., Jiménez, R., Echeverría, C.L., Pérez, C.L., Megías-Lobón, G., Ayats, J., Martín, M.T., Sánchez-Hellín, V., Ibáñez, E., Pemán, J., Pazos, C., Rodríguez-Mayo, M., Pérez-Ayala, A., Gómez, E., Serrano, J., Reigadas, E., Rodríguez, B., Zvezdanova, E., Díaz-García, J., González Leiva, J., Machado, M., García-Rodríguez, J., Vallejo, M.R., López-Soria, L., Marimón, J.M., Vicente, D., and Hernáez-Crespo, S.
- Subjects
Azoles ,Posaconazole ,Antifungal Agents ,Itraconazole ,Microbial Sensitivity Tests ,azoles ,Microbiology ,Aspergillus fumigatus ,03 medical and health sciences ,0302 clinical medicine ,EUCAST ,Drug Resistance, Fungal ,Amphotericin B ,parasitic diseases ,medicine ,Pharmacology (medical) ,spectrophotometric ,030212 general & internal medicine ,Pharmacology ,chemistry.chemical_classification ,Voriconazole ,0303 health sciences ,Aspergillus ,biology ,030306 microbiology ,biology.organism_classification ,bacterial infections and mycoses ,Infectious Diseases ,chemistry ,amphotericin B ,Mic values ,Azole ,medicine.drug - Abstract
The EUCAST EDef 9.3.2 procedure recommends visual readings of azole and amphotericin B MICs against Aspergillus spp. Visual determination of MICs may be challenging. In this work, we aim to obtain and compare visual and spectrophotometric MIC readings of azoles and amphotericin B against Aspergillus fumigatus sensu lato isolates. A total of 847 A. fumigatus sensu lato isolates (A. fumigatus sensu stricto [n = 828] and cryptic species [n = 19]) were tested against amphotericin B, itraconazole, voriconazole, posaconazole, and isavuconazole using the EUCAST EDef 9.3.2 procedure. Isolates were classified as susceptible or resistant/non-wild type according to the 2020 updated breakpoints. The area of technical uncertainty for the azoles was defined in the updated breakpoints. Visual and spectrophotometric (fungal growth reduction of >95% compared to the control, read at 540 nm) MICs were compared. Essential (±1 2-fold dilution) and categorical agreements were calculated. Overall, high essential (97.1%) and categorical (99.6%) agreements were found. We obtained 100% categorical agreements for amphotericin B, itraconazole, and posaconazole, and consequently, no errors were found. Categorical agreements were 98.7 and 99.3% for voriconazole and isavuconazole, respectively. Most of the misclassifications for voriconazole and isavuconazole were found to be associated with MIC results falling either in the area of technical uncertainty or within one 2-fold dilution above the breakpoint. The resistance rate was slightly lower when the MICs were obtained by spectrophotometric readings. However, all relevant cyp51A mutants were correctly classified as resistant. Spectrophotometric determination of azole and amphotericin B MICs against A. fumigatus sensu lato isolates may be a convenient alternative to visual endpoint readings.
- Published
- 2020