J. Stephen Guffey, William Payne and Annette Bednar
Background: Visible and near-IR energies have been shown to inhibit the growth of various microorganisms.
There may be clinical application for this inhibitory effect in the treatment of infected wounds particularly, and other infectious states generally.
Aim: The purpose of this study was to determine whether there was an interactive effect between dose and rate of energy delivery when using combined 464 and 850 nm light to inhibit Pseudomonas aeruginosa.
Methods: Solutions containing P. aeruginosa was irradiated with blue and infrared light (464 and 850 nm). The light energy was applied at two different doses and at two different rates of delivery. The doses employed included 9 and 30 Jcm-2. The rates of delivery used were 20 and 125 mWcm-2.
Design: An in vitro 2 × 2 factorial design was used to compare doses of 9 and 30 Jcm-2 and rates delivery of 20mWcm-2 and 125 mWcm-2 to determine kill rates compared to controls. Each dose was applied at each delivery rate.
Results: Student t-tests demonstrated (p=0.00) a significant kill rate at three of the four combinations. A two-way analysis of variance identified a significant interactive effect between dose and rate (F=94.717, p=0.00). Tukey’s HSD identified 30 Jcm-2 delivered at a 20 mWcm-2 as significantly different from the other combinations.
Conclusions: These data suggest that 1) visible and infrared light may be effective inhibitors of P. aeruginosa, and 2) both dose and rate of delivery are important factors to consider when using visible and infrared light energy to inhibit the growth of this organism.
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Journal of Lasers, Optics & Photonics received 279 citations as per Google Scholar report
