- 著者
- JUN IIJIMA TOSHIHIRO YAMASE
- 出版者
- The Society for Antibacterial and Antifungal Agents, Japan
- 雑誌
- Journal of Microorganism Control (ISSN:27586383)
- 巻号頁・発行日
- vol.28, no.3, pp.101-107, 2023 (Released:2023-10-23)
- 参考文献数
- 30
Abstract: Considering the lack of detailed research on the antibacterial mechanism of polyoxometalates, we examined the synergistic effect of novel bulky mixed Ti/W hetero-polyoxometalates (K9.5H2.5 [α-Ge2Ti4W20O78]・ 29H2O; αTi4, K9H5 [α-Ge2Ti6W18O77]・16H2O; αTi6, K23H5[α-Ge4Ti12W36O154]・39H2O; αTi12, K9H5 [β-Ge2Ti6W18O77]・ 45H2O; βTi6) with the antibiotic oxacillin against vancomycin intermediate-resistant Staphylococcus aureus (VISA) using fractional inhibitory concentration (FIC) index and growth curve in this study. All polyoxometalates used in this study showed remarkable synergistic effects with oxacillin. Its synergistic antibacterial mechanism was examined using reverse transcription PCR (RT-PCR) and penicillin binding protein-2’ (PBP2’) latex agglutination test. The results suggested that these polyoxometalates did not inhibit mecA gene transcription but resulted in PBP2’ protein malfunction. From these results, we concluded that the substances producing resistance in VISA were affected by polyoxometalates depending on their molecular size, facilitating a synergistic antibacterial effect with oxacillin.
- 著者
- RITSUKO KUWANA RYUJI YAMAZAWA RYOKO ASADA KIYOSHI ITO MASAKAZU FURUTA HIROMU TAKAMATSU
- 出版者
- The Society for Antibacterial and Antifungal Agents, Japan
- 雑誌
- Journal of Microorganism Control (ISSN:27586383)
- 巻号頁・発行日
- vol.28, no.1, pp.15-25, 2023 (Released:2023-05-08)
- 参考文献数
- 45
Abstract: Ultraviolet (UV) -C is widely used to kill bacteria as it damages chromosomal DNA. We analyzed the denaturation of the protein function of Bacillus subtilis spores after UV-C irradiation. Almost all of the B. subtilis spores germinated in Luria-Bertani (LB) liquid medium, but the colony-forming unit (CFU) of the spores on LB agar plates decreased to approximately 1/103 by 100 mJ/cm2 of UV-C irradiation. Some of the spores germinated in LB liquid medium under phase-contrast microscopy, but almost no colonies formed on the LB agar plates after 1 J/cm2 of UV-C irradiation. The fluorescence of the green fluorescent protein (GFP) -fused spore proteins, YeeK-GFP, YeeK is a coat protein, decreased following UV-C irradiation of over 1 J/cm2, while that of SspA-GFP, SspA is a core protein, decreased following UV-C irradiation of over 2 J/ cm2, respectively. These results revealed that UV-C affected on coat proteins more than core proteins. We conclude that 25 to 100 mJ/cm2 of UV-C irradiation can cause DNA damage, and more than 1 J/cm2 of UV-C irradiation can cause the denaturation of spore proteins involved in germination. Our study would contribute to improve the technology to detect the bacterial spores, especially after UV sterilization.