Julia Serrano-Lobo1,2, Ana Gómez1,2, Patricia Muñoz1,2,3,4, Pilar Escribano1,2, Jesús Guinea1,2,3. 1. Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain. 2. Instituto de Investigación Sanitaria Gregorio Marañón, 28007 Madrid, Spain. 3. CIBER Enfermedades Respiratorias-CIBERES (CB06/06/0058), 28029 Madrid, Spain. 4. Medicine Department, Faculty of Medicine, Universidad Complutense de Madrid, 28040 Madrid, Spain.
Abstract
We recently reported high essential (97.1%) and categorical (99.6%) agreements between azole and amphotericin B MICs against Aspergillus fumigatus sensu lato obtained by visual and spectrophotometric readings using a ≥ 95% fungal growth endpoint and following the EUCAST methodology (doi: 10.1128/AAC.01693-20). Here, we compared the aforementioned MICs against spectrophotometric MIC readings obtained using a ≥ 90% inhibition endpoint. Spectrophotometric readings using either ≥ 90% or ≥ 95% fungal growth inhibition resulted in high categorical (>99.9%) agreements with visual MIC readings against A. fumigatus sensu stricto. In contrast, agreements with visual MICs against cryptic species were higher with the use of a ≥ 95% fungal growth inhibition endpoint. LAY SUMMARY: Spectrophotometrically obtained MIC readings using either ≥ 90% or ≥ 95% fungal growth inhibition endpoints and following the EUCAST methodology are suitable against A. fumigatus sensu stricto. However, the ≥ 95% fungal growth inhibition endpoint is preferred against cryptic species.
We recently reported high essential (97.1%) and categorical (99.6%) agreements between azole and amphotericin B MICs against Aspergillus fumigatus sensu lato obtained by visual and spectrophotometric readings using a ≥ 95% fungal growth endpoint and following the EUCAST methodology (doi: 10.1128/AAC.01693-20). Here, we compared the aforementioned MICs against spectrophotometric MIC readings obtained using a ≥ 90% inhibition endpoint. Spectrophotometric readings using either ≥ 90% or ≥ 95% fungal growth inhibition resulted in high categorical (>99.9%) agreements with visual MIC readings against A. fumigatus sensu stricto. In contrast, agreements with visual MICs against cryptic species were higher with the use of a ≥ 95% fungal growth inhibition endpoint. LAY SUMMARY: Spectrophotometrically obtained MIC readings using either ≥ 90% or ≥ 95% fungal growth inhibition endpoints and following the EUCAST methodology are suitable against A. fumigatus sensu stricto. However, the ≥ 95% fungal growth inhibition endpoint is preferred against cryptic species.