Superoxide dismutase (SOD) and catalase are considered the most important antioxidant enzymes which protect fungus from the oxidant damage of reactive oxygen species. In this study, we collected 44 strains of Trichosporon asahii (T. asahii) from different sources and investigated their SOD and catalase activities. The results showed that the SOD and catalase activities of Clinical group were significantly higher than those of Environment group (p < 0.01). The SOD and catalase activities of T. asahii in Internal passage group went up gradually after passage in mice, and were significantly higher in 5th generation of Internal passage group (p < 0.05). The SOD and catalase activities of Fluconazole-resistant group strains also increased after resistant induction, and the SOD and catalase activities were significantly higher in the 10th generation of Fluconazole-resistant group (p < 0.05). This implied that T. asahii has stronger antioxidant ability. The strains of T. asahii from different sources have different antioxidant abilities, which mainly manifest in the difference of antioxidant enzymatic activities. Clinical group strains have the strongest antioxidant capacity; Internal passage group strains and Fluconazole resistant group strains better; Environmental group strains the lowest. These results also suggested that the antioxidant defensive response of T. asahii might be relevant to its infection mechanism and drug resistance mechanism.
Keywords: Catalase; Reactive oxygen species; Superoxide dismutase; Trichosporon asahii.