Comparison of E-Test, disk diffusion and a modified CLSI broth microdilution (M 38-A) method for in vitro testing of itraconazole, fluconazole and voriconazole against dermatophytes.

We compared two agar-based methods, the E-test and the disk diffusion method with the Clinical Laboratory Standards Institute (CLSI) reference broth microdilution method (CLSI M38-A; MD). Forty six dermatophytes strains including 30 Trichophyton mentagrophytes, 8 T. rubrum and 8 M. gypseum were tested against three antifungal agents, i.e., fluconazole (FLC), itraconazole (ITC) and voriconazole (VRC). The level of agreement between the E-test and MD (+/-2 dilutions) was 45.6% for fluconazole, 19.5% for itraconazole and 52.1% for voriconazole. The results obtained with disk diffusion had low correlation with the results obtained by the CLSI broth microdilution reference method with azoles.

[Study of resistance using the TRUGENE HIV-1 genotyping system and analysis of agreement between rule-based algorithms and virtual phenotyping]. / Estudio de resistencia mediante el sistema de genotipificación TRUGENE HIV-1 y análisis de concordancia entre algoritmos basados en reglas y el fenotipo virtual.

INTRODUCTION: This study attempts to describe the results obtained in the HIV resistance study performed with clinical samples obtained from patients receiving "HAART" therapy and to compare the results using different interpretation algorithms. METHODS: 397 samples have been analysed (TRUGENE HIV-1 GENOTYPING kit). The results were interpreted with the algorithms Visible Genetics and Retrogram. The concordance interalgorithm was done for 105 of these samples, including the virtual phenotype interpretation. RESULTS: The samples corresponded to multi regimen failure (39%), first and second failure (30.7% and 27.1% respectively). A 27.6% of the samples were wild type. The more frequent mutations to the ITIAN were T215Y/F (37.2%) and M184V (32.9%) following by other NAMS. The 69 insertion and Q151M complex had low representativity. For the ITINN K103N (25.8%), Y181C (11.2%) and G190A (10.9%). For the IP: key mutations L90M (26.1%), M46I (18.1%) and V82AFTS (12.9%); and accessory mutations L63P (50.5%), A71V (27.2%), L10I (25.2%) and M36I (19.2%). Low correlation was observed between interpretation systems, mainly for ITIAN and IP, being the virtual phenotype more flexible in the assignation of resistance. CONCLUSIONS: The requests for HIV resistance testing were similar for the three groups of patients. Many of the failures were the consequence of a poor adherence to the therapy. The mutation pattern found corresponded with the "TARGA" therapy. The low correlation found between interpretation systems, makes necessary the elaboration of a consensus algorithm.