Comparison of antifungal activities of zinc, copper, cerium oxide, silver, gold, and selenium nanoparticles against clinical isolates of Aspergillus

Aspergillus species are found as opportunistic agents to cause a wide variety of clinical manifestations. Regarding the drug resistance emergence against Aspergillus species, new aspects of using nanoparticles (NPs) as antifungal agents are considerable. This study takes a new approach to biosynthesized NPs of zinc oxide, copper oxide, cerium oxide, silver, gold, and selenium influence on the clinical isolates of Aspergillus species.

The antifungal activities of six NPs were examined against a total of 12 clinical isolates of Aspergillus species, including A. flavus (n=4), A. welwitschiae (n= 4), and A. fumigatus (n=4) based on the M38-A2 guideline.

According to minimum inhibitory concentration (MIC) values, NPs of ZnO, Ag, Au, and Se showed a significant antifungal effect. CuO-NPs and CeO2-NPs didn’t show an inhibitory effect against Aspergillus isolates. The MIC ranges of ZnO-NPs, Ag-NPs, Au-NPs, and Se-NPs were 128-512, 26-53, 21-85, and 6-26 µg⁄mL for A. fumigatus; and 512->512, 26-53, 85, and 1-13 µg⁄mL for A. welwitschiae, respectively. In addition, the MIC ranges of Ag-NPs and Se-NPs were 26-53 and 106-425 µg⁄mL for A. flavus, respectively. However, A. flavus were not inhibited by NPs of ZnO and Au.

Among the examined NPs, ZnO, Ag, Au, and Se showed a significant effect against Aspergillus isolates except for CuO and CeO2. However, Ag-NPs seemed to be the most effective nanoparticle against the Aspergillus species. Compared to other Aspergillus species, A. flavus was not inhibited by NPs of ZnO and Au.