Studies of the effect of antifungal agcnts on a filamentous fungus by a biocell tracer system

松冈博士开发的生物细胞示踪系统是一种测量菌丝生长的装置。利用该装置研究了抗真菌药物如阿替霉素B（AMPH）、氟胞嘧啶（5-FC）、咪康唑（MCZ）和氟康唑（FLCZ）对透明质酸的作用。培养皿底部用多聚赖氨酸包被，并在培养皿中心接种10^3个烟曲霉分生孢子。然后将液体培养基倒入容器中，并测量附着在底部的菌丝的生长速率。当添加抗真菌剂后生长速率下降到0时，我们判断菌丝生长被完全抑制。特别是该装置是非常有用的，以研究抗真菌剂的协同效应。AMPH和5-FC的协同作用受它们加入培养容器的时间的显著影响。当在培养基中先加入250 μ g/ml的5-FC，10分钟后再加入2 μ g/ml的AMPH时，菌丝生长立即下降。而先加入AMPH，10 min后再加入5-FC，菌丝生长逐渐下降。当单独使用AMPH（2 μ g/ml）和5-FC（250 μ g/ml）时，未观察到真菌菌丝的形态变化。另一方面，它们在这些浓度下的组合显示出明显的抑制活性。该方法可用于丝状真菌的抗真菌活性测定。

The biocell tracer system developped by Dr. Matsuoka is an apparatus to measure a hyphal growth. Using this apparatus, the effect of antifungal agents such as amphotericin B (AMPH), flucytosin (5-FC), miconazole (MCZ) and fluconazole (FLCZ) on hypae was studied. The bottom of culture vessel was coated with poly-L-lysine and 10^3 conidia of Aspergillus fumigatus were inoculated at the center of the vessel. Then liquid medium was poured into the vessel and the growth rate of a hypha adhering to the bottom was measured. When the growth rate dropped dto 0 after the addition of an antifungal agent, we judged the hyphal growth was completely inhibited. In particular this apparatus is very useful to study the synergistic effect of antifungal agents. The synergistic effect of AMPH and 5-FC was singnificantly influenced by timing of their addition to the culture vessel. When 250 mug/ml of 5-FC was used first into the medium and 2 mug/ml of AMPH was used 10 min later, the hyphal growth dropped immediately. However, when AMPH was added first and 5-FC was added 10 min later, the hyphal growth dropped gradually. When AMPH (2 mug/ml) and 5-FC (250 mug/ml) were used independently, no morphological changes of the fungal hyphae were observed. On the other hand, their combination at these concentrations showed a distinctinhibitory activity. This method is useful for antifungal activity testing of filamentous fungi.