Correlation between the E test and the CLSI M-38 A microdilution method to determine the activity of amphotericin B, voriconazole, and itraconazole against clinical isolates of Aspergillus fumigatus
Identificadores
URI: http://hdl.handle.net/20.500.12020/1245ISSN: 0732-8893
DOI: 10.1016/j.diagmicrobio.2006.09.003
Fecha
2007-03-01Tipo de documento
articleÁrea/s de conocimiento
Ciencias BiomédicasMateria/s Unesco
3201.03 Microbiología ClínicaResumen
The in vitro activities of amphotericin B, itraconazole, and voriconazole against 283 clinical isolates of Aspergillus fumigatus were studied by comparing the E test method with the reference procedure NCCLS (CLSI) M-38A. The methods were considered to agree when the results of the MICs by E test were within 2 dilutions of the MICs obtained by CLSI M-38 A. Agreement of readings at 24, 48, and 72 h of incubation was as follows: amphotericin B: 4.2%, 98%, and 40.6%; itraconazole: 92.5%, 100%, and 89.9%; and voriconazole: 98.9%, 100%, and 99.7%. The correlation between methods to classify the strains as susceptible or resistant was very good for itraconazole and voriconazole after 48 h of incubation, but 23% of the strains were incorrectly classified by E test for amphotericin B. The E test is an efficacious method for antifungal susceptibility testing in A. fumigatus for itraconazole and voriconazole when the plates are read after 48 h of incubation. The use of the E test to study the activity of amphotericin B should be avoided.