特比萘芬体外抗丝状真菌药物敏感试验:菌体不同形态对MIC的影响

Effect of Hyphal and Conidial form on the in vitro Antifungal Susceptibility Testing of Some Filamentous Fungi to Terbinafine

目的观察特比萘芬对部分深部丝状真菌和皮肤癣菌的MIC及分别接种未发芽孢子、发芽孢子和菌丝对MIC的影响.方法参考M38-P(丝状真菌稀释法抗真菌药物敏感性试验参考方案)试验方案及其改进方案,测定特比萘芬对7株曲霉、5株着色真菌、4株波氏假阿利什霉、4株尖端赛多孢子菌及5株皮肤癣菌的未发芽孢子、发芽孢子或菌丝的MIC,并比较相互间的差异.结果受试菌株以未发芽孢子形态接种时,曲霉MIC范围为≤0.03～0.5 μg/mL,暗色真菌的MIC范围为≤0.03～0.06μg/mL,波氏假阿利什霉及尖端赛多孢子菌的MIC均＞16 μg/mL,皮肤癣菌的MIC均≤0.03 μg/mL,提示上述菌株中除波氏假阿利什霉及尖端赛多孢子菌外,其余菌株体外均对特比萘芬敏感.所有受试菌中,除杂色曲霉和疣状瓶霉接种发芽孢子时MIC与接种菌丝时的MIC相差4倍外,其余菌株接种发芽孢子或菌丝悬液时的MIC与接种孢子时的MIC差异无显著性.结论受试曲霉、暗色真菌及皮肤癣菌体外均对特比萘芬敏感或较敏感.在丝状真菌的特比萘芬体外药物敏感试验中,接种易于获取并易于量化的未发芽孢子时的MIC可以反映特比萘芬体外对发芽孢子及菌丝的抗菌活性.

Objective To compare the in vitro antifungal susceptibility of germinated, ungerminated conidia and hyphae of some filamentous fungi and dermatophytes to terbinafine. Methods The MICs of terbinafine for 7 isolates of Aspergillus spp., 5 isolates of dematiaceous fungi, 4 isolates of Pseudallescheria boydii, 4 isolates of Scedosporium apiospermum and 5 isolates of dermatophytes were examined using the NCCLS M38-P microdilution method. The isolates were inoculated in three different forms, ungerminated conidia, germinated conidia and hyphae respectively, in the tests. Results The MICs of terbinafine for the isolates of Aspergillus spp., dematiaceous fungi, Pseudallescheria boydii, Scedosporium apiospermum, and dermatophytes were ≤0.03 ~ 0.5 μg/mL, ≤0.03 ~ 0.06 μg/mL, > 16 μg/mL, > 16 μg/mL, and ≤0.03 μg/mL , respectively. The MICs did not show significant differences among the ungerminated conidia and the germinated conidia for all the isolates tested except A.versicolor and Phialophora verrucosa. Conclusions Terbinafine is effective against the isolates of Aspergillus spp., dematiaceous fungi and dermatophytes in vitro except Pseudallescheria boydii and Scedosporium apiospermum. The MIC of terbinafine obtained with ungerminated conidia may reflect the antifungal activity of terbinafine against germinated conidia and hyphae of some filamentous fungi in vitro.