Nectar yeasts of the Metschnikowia clade are highly susceptible to azole antifungals widely used in medicine and agriculture

The widespread use of azole antifungals in medicine and agriculture and the resulting long-persistent residues could potentially affect beneficial fungi. However, there is very little information on the tolerance of non-target environmental fungi to azoles. In this study, we assessed the susceptibil...

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Detalhes bibliográficos
Autores: Álvarez-Pérez, Sergio, Vega, Clara de, Pozo, María I., Lenaerts, Marijke, Assche, Aldo van, Herrera, Carlos M., Jacquemym, H., Lievens, Bart
Tipo de documento: artigo
Estado:Versión aceptada para publicación
Data de publicação:2016
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/146573
Acesso em linha:http://hdl.handle.net/10261/146573
Access Level:Acceso aberto
Palavra-chave:Broth microdilution
Metschnikowia clade
Insect pollinators
Floral nectar
EUCAST
Azoles
Descrição
Resumo:The widespread use of azole antifungals in medicine and agriculture and the resulting long-persistent residues could potentially affect beneficial fungi. However, there is very little information on the tolerance of non-target environmental fungi to azoles. In this study, we assessed the susceptibility of diverse plant- and insect-associated yeasts from the Metschnikowia clade, including several ecologically important species, to widely used medical and agricultural azoles (epoxiconazole, imazalil, ketoconazole and voriconazole). A total of 120 strains from six species were tested. Minimum inhibitory concentrations (MICs) were determined by the EUCAST broth microdilution procedure after some necessary modifications were made. The majority of species tested were highly susceptible to epoxiconazole, ketoconazole and voriconazole (>95% of strains showed MICs ≤ 0.125 mg l). Most strains were also very susceptible to imazalil, although MIC values were generally higher than for the other azoles. Furthermore, certain Metschnikowia reukaufii strains displayed a 'trailing' phenotype (i.e. showed reduced but persistent growth at antifungal concentrations above the MIC), but this characteristic was dependent on test conditions. It was concluded that exposure to azoles may pose a risk for ecologically relevant yeasts from the Metschnikowia clade, and thus could potentially impinge on the tripartite interaction linking these fungi with plants and their insect pollinators.