Abstract: 【Abstract】 Objective To evaluate the in vitro antifungal activity of berberine against Talaromyces marneffei（TM） in yeast phase. Methods There were 21 TM strains, including l standard strain（ATCC22019）, 10 clinical isolates and 10 isolates from wild bamboo rats. TM strain suspensions at a concentration of （1 - 5） × 103 colony-forming units/ml were incubated in microdilution plates containing difierent concentrations of berberine, fluconazole, itraconazole, voriconazole, amphotericin B or caspofungin at 37 ℃ for 48 hours. Meanwhile, the wells containing only culture media and TM strains but without antifungal drugs served as positive control group, and those containing only culture media served as the negative control group. The minimum inhibitory concentrations （MICs） of antifungal drugs against yeasts were determined according to the Clinical and Laboratory Standards Institute （CLSI） broth microdilution susceptibility method （M27-A3 Document）. Results The MICs of the above antifungal drugs were all within the reference ranges for the quality control strain （ATCC22019）, and TM strains grew well in the positive control wells. The MIC ranges of berberine, itraconazole, voriconazole, amphotericin B and caspofungin against TM strains were 32 - 64 mg/L, 0.06 - 0.125 mg/L, 0.06 - 0.125 mg/L, 1 - 2 mg/L and 16 - 32 mg/L respectively; the MIC range of fluconazole was 2 - 4 mg/L for non-resistant strains, and 128 mg/L for fluconazole-resistant clinical strains. Conclusion Berberine exhibits antifungal activity against TM in yeast phase.

Key words: Berberine, Fungi, Microbial sensitivity tests, Talaromyces marneffei