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仪器。利用该装置研究了两性霉素B （AMPH）、氟胞菌素（5-FC）、咪康唑（MCZ）和氟康唑（FLCZ）等抗真菌药物对菌丝的抑制作用。在培养容器底部包被聚l -赖氨酸，在容器中心接种10^3个烟曲霉分生孢子。然后将液体培养基倒入容器中，测量菌丝附着在容器底部的生长速率。当添加抗真菌剂后菌丝生长速率降至0时，我们判断菌丝生长完全被抑制。特别是该仪器对研究抗真菌药物的协同作用非常有用。AMPH和5-FC的协同效应受其添加时间的显著影响。先加入250杯/ml的5-FC， 10分钟后加入2杯/ml的AMPH，菌丝生长立即下降。但先添加AMPH， 10 min后添加5-FC，菌丝生长逐渐下降。单独使用AMPH（2杯/ml）和5-FC（250杯/ml）时，真菌菌丝形态未见变化。另一方面，它们在这些浓度下的组合表现出明显的抑制活性。该方法可用于丝状真菌的抗真菌活性检测。

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.