The Interaction of Dose and Rate of Delivery Using Visible and Infrared Light toInhibit Pseudomonas aeruginosa In vitro
- *Corresponding Author:
- J. Stephen Guffey
Department of Physical Therapy
Arkansas State University, State University
E-mail: [email protected]
Received Date: February 14, 2014; Accepted Date: April 17, 2014; Published Date: April 23, 2014
Citation: Guffey JS, Payne W, Bednar A (2014) The Interaction of Dose and Rate of Delivery Using Visible and Infrared Light to Inhibit Pseudomonas aeruginosa In vitro. J Laser Opt Photonics 1:104. doi:10.4172/2469-410X.1000104
Copyright: © 2014 Guffey JS, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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.