Background: Despite of many studies on antibacterial activity of titanium dioxide (TiO2), its antifungal properties are not yet well evaluated. The aim of our study is to exam the activity of nanosized TiO2 against yeast cells.
Material/methods: TiO2 used was synthesized by sol-gel method and characterized as anatase with particles size about 20 nm. Its antifungal activity was examined against C.albicans, C.tropicalis, C.lusitaniae, C.glabrata and C.krusei, using the following experimental setup: concentration of TiO2 powder – 1 mg/ml, 100 ml fungal suspension with cell density about 104 CFU/ml and BLB lamp (50 Hz 8W T5 with emission 365 nm) situated at distance 10 cm. At regular intervals of time, samples were taken and serial dilutions were prepared. The number of viable cells was detected by spread plate method. For determination of the post-irradiation effect, the treated suspensions were tested after 48 h dark period.
Results: The data obtained about antifungal activity of TiO2 are in agreement with photocatalytic properties of metal oxide nanoparticles After 120 min UV-A photocatalytic treatment with 1 mg/ml TiO2, the number of colonies of C.albicans and C.tropicalis decrease from about 104 CFU/ml to less than 5 CFU/ml with 100% reduction index. Final reduction index in C.lusitaniae and C.glabrata is 99.643% and 99.898%, respectively. These data indicate strong photocatalytic fungicidal effect of TiO2 on the tested fungi. At the same conditions, the colonies of C.krusei are reduced with 98%. Obviously, in this case it is necessary a longer exposure time to achieve a significant reduction of the yeast cells.
Conclusions: Nonhydrolytic synthesized nanosized TiO2 possesses antifungal activity against isolates of the genus Candida with some differences in the speed of photocatalytic process.
Full conference title:
- ECCMID 26th (2016)