摘要目的:探讨不同能量Q开关Nd:YAG 1 064 nm激光对糠秕马拉色菌的细胞活性、蛋白酶活性及菌体结构的影响。方法:选用糠秕马拉色菌标准株，分别予以Q开关Nd:YAG 1 064 nm激光0（对照组）、500、600、700、800、900 mJ能量照射，培养7 d后测量各组菌落直径及菌落数，评估菌体细胞活性，采用全脂牛奶平板法测定蛋白酶活性，透射电镜观察各组菌体超微结构。多组间比较采用单因素方差分析，组间两两比较采用LSD- t检验，激光能量与菌落直径、菌落数及蛋白酶活性的相关性采用Pearson相关分析。 结果:对照组及500、600、700、800、900 mJ组菌落直径[（4.05 ± 0.69）、（3.76 ± 0.51）、（3.28 ± 0.41）、（3.09 ± 0.72）、（2.54 ± 0.64）、（2.43 ± 0.41）mm]、菌落数（4 787 ± 597、4 287 ± 761、1 879 ± 275、1 082 ± 248、209 ± 42、72 ± 31）差异均有统计学意义（ F值分别为14.83、231.85， P < 0.05），600、700、800、900 mJ组菌落直径、菌落数均小于对照组（均 P < 0.05）。激光能量与菌落直径和菌落数均呈负相关（ r值分别为-0.67、-0.91， P < 0.05）。对照组、500 mJ组、700 mJ组、900 mJ组蛋白酶活性差异有统计学意义（ F = 346.60， P < 0.05），700 mJ、900 mJ组蛋白酶活性均低于对照组（ P < 0.05）。激光能量与蛋白酶活性呈负相关（ r = -0.94， P < 0.05）。透射电镜下观察到对照组菌体结构完整，500 mJ组菌体结构较完整，600 ~ 900 mJ组结构明显受破坏，且激光能量越大菌体结构破坏越严重。 结论:Q开关Nd:YAG 1 064 nm激光可影响糠秕马拉色菌细胞及蛋白酶活性，破坏菌体结构。

abstractsObjective:To investigate the effect of 1 064-nm Q-switched Nd:YAG laser at different energy settings on cell viability, protease activity and structures of Malassezia furfur. Methods:Cultured standard strains of Malassezia furfur were divided into several groups to be irradiated with 1 064-nm Q-switched Nd:YAG laser at different energies of 0 (control group) , 500, 600, 700, 800 and 900 mJ, respectively. Then, fungal suspensions in the above groups were inoculated onto the Leeming & Notman medium separately. After 7-day culture, the diameter and number of colonies were measured to evaluate the fungal cell viability, the protease activity was measured by using the whole-milk plate medium, and the ultrastructure of Malassezia furfur in each group was observed by transmission electron microscopy. One-way analysis of variance was used for comparisons among multiple groups, least significant difference- t test for multiple comparisons, and Pearson correlation analysis for analyzing correlations of laser energy with colony diameter, number and protease activity. Results:The colony diameter and number both significantly differed among the control group, 500-, 600-, 700-, 800- and 900-mJ groups (colony diameter: 4.05 ± 0.69, 3.76 ± 0.51, 3.28 ± 0.41, 3.09 ± 0.72, 2.54 ± 0.64 and 2.43 ± 0.41 mm, respectively; colony number: 4 787 ± 597, 4 287 ± 761, 1 879 ± 275, 1 082 ± 248 and 209 ± 42, 72 ± 31 colony-forming units, respectively; F = 14.83, 231.85, respectively, both P < 0.05) , and were significantly decreased in the 600-, 700-, 800- and 900-mJ groups compared with the control group (all P < 0.05) . The laser energy was negatively correlated with the colony diameter and number ( r = -0.67, -0.91, respectively, both P < 0.05) . The protease activity significantly differed among the control group, 500-, 700- and 900-mJ groups ( F = 346.60, P < 0.05) , and was significantly lower in the 700- and 900-mJ groups than in the control group (both P < 0.05) . There was a negative correlation between the laser energy and protease activity ( r = -0.94, P < 0.05) . Transmission electron microscopy showed intact fungal structures in the control group, relatively intact fungal structures in the 500-mJ group, and obviously damaged fungal structures in the 600- to 900-mJ groups, and the greater the laser energy, the more severely the fungal structures were damaged. Conclusion:The 1 064-nm Q-switched Nd:YAG laser could affect the cell viability of and protease activity in Malassezia furfur, and damage its structures.