OBJECTIVE: To determine whether manipulation of dose, wavelength, and rate of energy delivery could delay the onset of previously demonstrated Staphylococcus aureus resistance to blue light. METHODS: The organism was treated in vitro with 405 nm, 464 nm, and combined 464 nm and with 850 nm light emitted from a supraluminous diode (SLD) array. Doses of 9 J/cm2 and 30 J/cm2 were used. Rates of energy delivery were also varied from 10 mW/cm2 to 125 mW/cm2. Seven stages were employed to test for resistance formation. Colony counts were performed and compared to untreated controls using Student t tests and one-way ANOVA with Tukey post hoc analysis. RESULTS: A best dose, wavelength, and rate of delivery combination was determined at each stage and it did produce a significant kill rate (P ≤ 0.05) at each stage. Analysis of variance demonstrated that no loss of effectiveness (formation of resistance) occurred over the 7 stages. CONCLUSIONS: Appropriate combinations of dose, wavelength, and rate of energy delivery can delay resistance formation to light as a bactericidal agent for S. aureus. .
OBJECTIVE: To determine whether manipulation of dose, wavelength, and rate of energy delivery could delay the onset of previously demonstrated Staphylococcus aureus resistance to blue light. METHODS: The organism was treated in vitro with 405 nm, 464 nm, and combined 464 nm and with 850 nm light emitted from a supraluminous diode (SLD) array. Doses of 9 J/cm2 and 30 J/cm2 were used. Rates of energy delivery were also varied from 10 mW/cm2 to 125 mW/cm2. Seven stages were employed to test for resistance formation. Colony counts were performed and compared to untreated controls using Student t tests and one-way ANOVA with Tukey post hoc analysis. RESULTS: A best dose, wavelength, and rate of delivery combination was determined at each stage and it did produce a significant kill rate (P ≤ 0.05) at each stage. Analysis of variance demonstrated that no loss of effectiveness (formation of resistance) occurred over the 7 stages. CONCLUSIONS: Appropriate combinations of dose, wavelength, and rate of energy delivery can delay resistance formation to light as a bactericidal agent for S. aureus. .
Authors: Yucheng Wang; Ying Wang; Yuguang Wang; Clinton K Murray; Michael R Hamblin; David C Hooper; Tianhong Dai Journal: Drug Resist Updat Date: 2017-10-13 Impact factor: 18.500
Authors: Aleksandra Rapacka-Zdonczyk; Agata Wozniak; Michal Pieranski; Anna Woziwodzka; Krzysztof P Bielawski; Mariusz Grinholc Journal: Sci Rep Date: 2019-07-01 Impact factor: 4.379