The bactericidal efficacy of a photocatalytic TiO(2) particle mixture with oxidizer against Staphylococcus aureus.

By proving the bactericidal effects of a low-concentration titanium dioxide (TiO(2)) particle mixture against Staphylococcus aureus, we hope to ultimately apply a mixture of this type as part of a clinical treatment regimen. A bacterial suspension of S. aureus 1 x 10(5) CFU/ml was added dropwise to a TiO(2) particle mixture (19 ppm TiO(2)) and irradiated by ultraviolet (UV) light. The colony-forming units were counted and the bacterial survival rate was calculated. In the control sample, the bacterial survival rate was 83.3% even after 120 min. In the TiO(2) mixture + UV sample, the bacteria count dropped sharply, reaching 17.3% of the baseline value at 30 min and 0.4% at 60 min. TiO(2) particles dispersed in water mixtures are known to elicit highly efficient UV absorption and greater bonding to bacteria. A reaction of the TiO(2) with another oxidizer altered the aqueous pH and accelerated the photocatalytic chemical reaction. The TiO(2) particle mixture showed high antibacterial action against S. aureus even at a low concentration.