Isolation of azole-resistant Aspergillus fumigatus from imported plant bulbs in Japan and the effect of fungicide treatment

Increasing numbers of azole-resistant Aspergillus fumigatus (ARAf) in the environment have become a global public health issue. We surveyed tulip bulbs that were imported from the Netherlands and found that 6.3–15.8% of bulbs were contaminated by ARAf with a tandem-repeat mutation in the promoter region of the cyp51A gene. We also showed that fungicide treatment of the tulip bulbs by benomyl or prochloraz effectively reduced the rate of isolation. This is the first report demonstrating a method of eliminating human fungal pathogens from plant bulbs.