Prevalence and phenotypic features of voriconazole persistence in <i>Aspergillus fumigatus</i>

Antifungal persistence has emerged as an important survival strategy that may contribute to treatment failure, yet its prevalence and phenotypic characteristics in Aspergillus fumigatus populations remain incompletely defined. Here, we systematically assessed voriconazole persistence in a collection of 225 azole-susceptible A. fumigatus isolates derived from clinical (n = 208) and environmental (n = 17) sources in China. Persistence-associated behavior was evaluated using complementary broth microdilution-based germination assays, agar disk diffusion assays, and time-kill analyses. Approximately 10% of azole-susceptible isolates reproducibly exhibited persistence-associated phenotypes. Environmental conditions strongly influenced persistence-associated growth, as iron chelation selectively suppressed persistence. Importantly, persistent isolates showed an increased tendency to acquire azole resistance during prolonged antifungal exposure. Together, this study provides an isolate-based assessment of antifungal persistence in A. fumigatus, highlighting its phenotypic diversity and potential role in resistance evolution. These findings underscore the persistence of antifungal susceptibility as an additional dimension, with important implications for therapy and resistance development.