Fungal colonization and antifungal resistance in marine mammals remain critically understudied, despite growing recognition of their ecological and clinical importance. This study presents the first comprehensive culture-based assessment of the respiratory fungal community and antifungal susceptibility patterns in common bottlenose dolphins ( Tursiops truncatus ) maintained under human care. Using culture-based methods and differential incubation temperatures, we identified a diverse community of fungi from exhaled breath samples of ten dolphins, including clinically relevant yeasts and filamentous fungi. Aspergillus species were the most frequently isolated genus, with A. niger , A. terreus , and several previously unreported species in cetaceans such as A. glaucus and Fusarium dimerum . Among the yeasts, Candida albicans , Nakaseomyces glabratus , and Meyerozyma guilliermondii were recovered. Antifungal susceptibility testing revealed azole resistance in isolates of Candida and related species, Mucor , and Aspergillus spp., including multidrug-resistant profiles, while susceptibility to echinocandins and amphotericin B was preserved. Notably, resistant isolates were detected in dolphins with a history of antifungal exposure, raising concern about potential selective pressure in managed settings. No pathogenic fungi were recovered from aquarium water, suggesting endogenous or close-contact sources. These findings highlight the need for routine fungal surveillance in marine mammal facilities and contribute novel data on host-associated fungal communities in aquatic mammals. More broadly, they underscore the importance of a One Health approach to fungal ecology and resistance in marine environments.
García-Bustos et al. (Fri,) studied this question.