APNP对白念珠菌杀菌效果研究

Sterilization of Candida albicans by Atmospheric pressure non-equilibrium plasma

目的研究常压低温等离子体(APNP)喷流对白念珠菌的杀灭作用,并初步探讨其杀菌机制。方法观察白念珠菌标准株经不同放电气体流量、作用时间及作用距离的APNP喷流处理后的菌落生长情况,并利用扫描电镜与透射电镜观察处理后念珠菌细胞内外超微结构的变化。结果经APNP处理后的菌株生长明显被抑制,通入的放电气体He/O2以2/0.06 L/min的抑制作用比2/0.02 L/min明显,处理时间10 min明显优于2 min,作用距离1 cm优于2 cm。扫描电镜观察APNP处理后的菌体细胞壁有不同程度的破裂,菌体干瘪,透射电镜下可见菌体细胞壁、细胞膜破裂,胞内物质外漏,细胞内物质稀疏。结论 APNP喷流对白念珠菌有明显的杀灭效果,且放电气体中氧气含量相对越大,处理时间越长,作用距离越短,杀菌效果也越明显。其主要杀菌机制可能与APNP中活性粒子导致微生物细胞壁、细胞膜的破裂有关。

Objective To investigate the sterilization effect of Atmospheric pressure non-equilibrium plasma （APNP） to Candida albicans and its mechanisms. Methods Standard strains of Candida albicans were treated with APNP with different gas flows, operation durations and distances. Growth of the strains was observed, CFU was calculated with plate counting method and the changes of cell structure were observed with electron microscope. Results The growth of Candida albicans strains was suppressed significantly after treated with APNP. The inhibitory effect was greater with the gas flow of 2/0.06 L/min （ He/O2 ） than with that of 2/0.02 L/min, the operation duration of 10 min was better than 2 min, and the distance of 1 cm was better than 2 cm. After exposure to APNP, the fungal cells showed wizened, broken cell wall and cell membrane, leakage of cell content under electron microscopes. Conclusions The sterilization effect of APNP on Candida albicans is significant. This effect is promoted with more O2, longer operation duration and nearer distance. The main mechanism may be attributed to the active particles, which cause the breaking of the cell wall and membrane.