Photodynamic Inactivation of Enterovirus 71 with Methylene Blue

• Main Authors: Shuang-Rung Huang, 黃炫榕
• Other Authors: Chun-Keung Yu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/34332924197741397273

碩士 === 國立成功大學 === 微生物及免疫學研究所 === 95 === Photodynamic treatment (PDT) has been applied to destroy cancer cells and a variety of microorganisms including bacteria and viruses by combining light and photosensitizing agents in an oxygen-rich environment. Certain photosensitizing agents can bind strongly with nucleic acids and generate reactive oxygen species after activation upon illumination, which is responsible for the disruption of viral structures and viral nucleic acid-protein cross-linkage. In this study, we have tested whether methylene blue (MB), the most widely used photosensitizing agent, is feasible for photodynamic inactivation of enterovirus 71 (EV71), a non-enveloped virus belonging to the Picornaviridae family, which can cause severe central nervous system infections and has neither anti-viral drug nor vaccine available. EV71 is transmitted through oral-fecal route and resistant to 70 % alcohol disinfection. We demonstrated that EV71 on solid surface could be photodynamically inactivated by illumination with visible light in the presence of MB. Photodynamic inactivation of EV71 in suspensions by MB showed dose- and light-intensity-dependent manners. Illumination without MB or MB alone in the dark and preactivation of MB showed no such effect. The optimal condition for photoinactivating EV71 required a light intensity of 200 J/cm2 and MB of 0.1 mM. This PDT condition could also inactivate other enteroviruses, including poliovirus 1, cosackievirus A2, A3, A16, and B3. Western blot and reverse-transcriptase PCR analysis indicated that the viral proteins and genome were broken after PDT. Thus, protein and genome damage appears to be involved in photoinactivation of EV71. In conclusion, PDT can inactivate EV71 efficiently and it may provide a method of eliminating environmental contaminated source of EV71 to prevent EV71 infections.