著者
Tomoyuki Nakada Kiyoshi Konishi
出版者
The Pharmaceutical Society of Japan
雑誌
BPB Reports (ISSN:2434432X)
巻号頁・発行日
vol.6, no.3, pp.81-86, 2023 (Released:2023-05-12)
参考文献数
36

Irradiation with 405-nm visible violet LED light without additional photosensitizers decreased the viability of the aggressive periodontopathic bacterium Aggregatibacter actinomycetemcomitans. The number of CFU/mL decreased linearly on a logarithm chart versus irradiation time, with a 1-log reduction time of 1.32 min. The antimicrobial photodynamic effect of 405-nm LED light involved inhibition of the activity of membrane-bound cytochrome bd, a terminal quinone: oxygen oxidoreductase, and quinol peroxidase, a terminal quinone:H2O2 oxidoreductase. The 405-nm LED irradiation reduced minus oxidized difference spectrum showed that the 640-nm peak (α-peak of heme d) completely disappeared, and the height of the 556-nm (α-peak of hemes b and c) and Soret band (425 nm; γ-peak of hemes b, c, and d) was reduced to approximately half of the peak heights of non-irradiated controls. Survival of bacteria-injected silkworm larvae was also examined. Fifth-instar silkworm larvae were almost completely killed by approximately 40 h after bacterial injection, but almost all silkworm larvae irradiated with 405-nm LED light (20 mW/cm2 for 5 min, energy density: 6 J/cm2) survived, similar to controls not injected with bacteria, indicating that 405-nm LED light killed the injected bacteria. The bactericidal effect of 405-nm blue-light on A. actinomycetemcomitans is primarily due to disruption of cytochrome bd oxidase and quinol peroxidase of the respiratory chain.
著者
Takekatsu Shibata Ryuta Urakawa Chikako Ono Yukihiro Akeda Takayoshi Sakai Shigeto Hamaguchi Kiyoto Takamori Tsuyoshi Inoue Kazunori Tomono Kiyoshi Konishi Yoshiharu Matsuura
出版者
The Pharmaceutical Society of Japan
雑誌
BPB Reports (ISSN:2434432X)
巻号頁・発行日
vol.4, no.3, pp.78-84, 2021 (Released:2021-05-26)
参考文献数
39
被引用文献数
8

Matching transformation system (MA-T) is an on-demand aqueous chlorine dioxide solution. It is a disinfectant developed to maximize the safety of chlorine dioxide radical in water and its effectiveness against various microorganisms. In this study, we examined the safety and effectiveness of MA-T for its use in various infectious disease countermeasures, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and consider if MA-T can be implemented in society. To validate the safety of MA-T, we conducted safety tests and efficacy tests in accordance with GLP-based reliability criteria. To evaluate the efficacy, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) confirmation tests against various bacteria, and virus inactivation test against various viruses including SARS-CoV-2 by TCID50 method were performed. The results of safety tests showed that MA-T was at least as safe as Japanese tap water. As a result of efficacy tests for microorganisms, MA-T was effective against many bacteria. Efficacy tests for virus showed that MA-T inactivates SARS-CoV-1, Middle East respiratory syndrome coronavirus (MERS-CoV), rotavirus A (RV-A), hepatitis C virus (HCV), dengue virus (DENV), and hepatitis B virus (HBV). MA-T also inactivated 99.98% of SARS-CoV-2, which is equivalent to ethanol for disinfection. MA-T has proven to be a safe and effective disinfectant. MA-T is a next-generation disinfectant that has the potential to be safer and more effective than conventional chlorine disinfectants and other disinfectants. It also proved to be an effective disinfectant against SARS-CoV-2, which is currently causing pandemic all over the world.