Abstract: Objective To evaluate the susceptibility of itraconazole-resistant Aspergillus fumigatus isolates to four other antifungal drugs.Methods Six strains of Aspergillus fumigatus were serially isolated from a patient with lung aspergilloma,who was resistant to itraconazole therapy.Clinical Laboratory Standard Institute broth microdilution method M38-A and E-test were applied to test the susceptibility of A.fumigatus strains to amphotericin B,itraconazole,voriconazole,caspofungin and micafungin.Results With M38-A method,the minimal inhibitory concentration(MIC)of itraconazole was 0.5μg/mL for 2 strains and more than 16μg/mL for the other 4 strains;the MICs of amphotericin B and voriconazole were 1μg/mL and 0.25-1μg/mL respectively for all the 6 strains;and the minimal effective concentration(MEC)of caspofungin and micafungin were no more than 0.03μg/mL for all the 6 strains.Moreover,E-test results also revealed that caspofungin and voriconazole had a good antifungal activity against all the strains,including the 4 itraconazole-resistant ones.Conclusion The itraconazole-resistant A.fumigatus strains isolated from a patient with lung aspergilloma are susceptible to amphotericin B,voriconazole,caspofungin,and micafungin.

Key words: Aspergillus fumigatus, Itraconazole, Drug resistance, fungal