Emergence of Triazole Resistance in Aspergillus fumigatus Exposed to Paclobutrazol.

As a global health problem, the source of triazole resistance in Aspergillus fumigatus has gained much attention. This study was conducted to explore whether the triazole plant regulator paclobutrazol could evolve triazole resistance in A. fumigatus. The results indicated that two triazole-resistant strains with hereditary stability were isolated from liquid medium and soil. The up-regulation of cyp51A, cyp51B, AtrF, cdr1B, AfuMDR1, AfuMDR2, and AfuMDR4 played an important role in these resistant strains. The triazole-resistance in A. fumigatus could depend on the selective pressure of paclobutrazol concentration and exposure time. These results indicate that the application of paclobutrazol may result in the emergency of triazole resistance in A. fumigatus and thus have a potential risk for the treatment of invasive aspergillosis.