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Background: During recent years, the incidence of serious infections caused by opportunistic fungi has increased dramatically due to alterations of the immune status of patients with hematological diseases, malignant tumors, transplantations and so forth. Unfortunately, the wide use of triazole antifungal agents to treat these infections has lead to the emergence of Aspergillus spp. resistant to triazoles. The present study was to assess the in vitro activities of five antifungal agents (voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin) against different kinds of Aspergillus spp. that are commonly encountered in the clinical setting., Methods: The agar-based Etest MIC method was employed. One hundred and seven strains of Aspergillus spp. (5 species) were collected and prepared according to Etest Technique Manuel. Etest MICs were determined with RPMI agar containing 2% glucose and were read after incubation for 48 hours at 35°C. MIC(50), MIC(90) and MIC range were acquired by Whonet 5.4 software., Results: The MIC(90) of caspofungin against A. fumigatus, A. flavus and A. nidulans was 0.094 µg/ml whereas the MIC(90) against A. niger was 0.19 µg/ml. For these four species, the MIC(90) of caspofungin was the lowest among the five antifungal agents. For A. terrus, the MIC(90) of posaconazole was the lowest. For A. fumigatus and A. flavus, the MIC(90) in order of increasing was caspofungin, posaconazole, voriconazole, itraconazole, and amphotericin B. The MIC of amphotericin B against A. terrus was higher than 32 µg/ml in all 7 strains tested., Conclusions: The in vitro antifungal susceptibility test shows the new drug caspofungin, which is a kind of echinocandins, has good activity against the five species of Aspergillus spp. and all the triazoles tested have better in vitro activity than traditional amphotericin B.

Our objective was to develop new approaches to the chemotherapy of invasive infections caused by Fonsecaea monophora. The in vitro effects of a combination of terbinafine with itraconazole on 18 clinical isolates were evaluated using a checkerboard microdilution method. The mode of interaction between the two drugs on the 18 isolates was analyzed using fractional inhibitory concentration index (FICI) analysis. FICI analysis demonstrated that 12 (67%) were synergistic, 4 (22%) were additive, and 2 (11%) were indifferent, with no antagonism being observed. The minimal inhibitory concentrations (MICs) obtained with the terbinafine-itraconazole combination were within levels that can be achieved in plasma at clinically relevant doses. Our results indicate the terbinafine-itraconazole combination may be an effective therapy for Fonsecaea monophora infection, which should be tested in clinical setting with patients with this disease.