Miamiensis avidus causes scuticociliatosis in cultured olive flounders (Paralichthys olivaceus), leading to economic losses in aquaculture in Korea. Quantitative evaluation of the viability of M. avidus is important to develop an effective vaccine or chemotherapeutic agent against it. We used a colorimetric assay based on the reduction of 2-(4-Iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-1) to quantify the viability of M. avidus. Using this method, we investigated the effect of protease inhibitors on the viability of M. avidus. The assay showed a clear difference in the optical density (OD) of over 10⁴ ciliates, and the metalloprotease inhibitors 1, 10-phenanthroline and ethylenediaminetetraacetic acid (EDTA) reduced the viability of M. avidus by more than 90% when used at concentration of 5 mM and 100 μM, respectively. However, different morphological changes in the parasite were observed when exposed to these two inhibitors. These results indicate that the WST-1 assay is a simple and reliable method to quantify the viability of M. avidus, and metalloproteases are excellent targets for the development of agents and vaccines to control M. avidus infection.

迈阿密红皮蝇导致养殖的比目鱼（Paralichthys olivaceus）发生皮肤cut虫病，导致韩国水产养殖的经济损失。狂犬分枝杆菌的生存能力的定量评估对于开发针对其的有效疫苗或化学治疗剂很重要。我们使用了基于2-（4-碘苯基）-3-（4-硝基苯基）-5-（2,4-二磺基苯基）-2H-四唑鎓（WST-1）还原的比色法来定量M的活力。avidus。使用这种方法，我们研究了蛋白酶抑制剂对M. avidus活力的影响。该测定表明光密度（OD）明显超过10 ⁴纤毛虫和金属蛋白酶抑制剂1、10-菲咯啉和乙二胺四乙酸（EDTA）分别以5 mM和100μM的浓度使用时，会使狂犬病杆菌的生存力降低90％以上。然而，当暴露于这两种抑制剂时，观察到寄生虫的不同形态变化。这些结果表明，WST-1测定法是一种简单可靠的方法，可量化抗狂犬病菌的生存能力，金属蛋白酶是开发用于控制抗狂犬病菌感染的试剂和疫苗的极佳靶标。