Bactericidal action of high-power Nd:YAG laser light on Escherichia coli in saline suspension

Ward, G.D., Watson, I.A. , Stewart-Tull, D.E.S., Wardlaw, A.C., Wang, R.K., Nutley, M.A. and Cooper, A. (2000) Bactericidal action of high-power Nd:YAG laser light on Escherichia coli in saline suspension. Journal of Applied Microbiology, 89(3), pp. 517-525. (doi: 10.1046/j.1365-2672.2000.01144.x)

Abstract

Infra-red light (1064 nm) from a high-power Nd:YAG laser caused more than 90% loss of viability of <i>Escherichia coli</i> during exposures that raised the temperature of PBS suspensions of the bacteria to 50 °C in a thermocouple-equipped cuvette. In contrast, there was minimal loss of viability after heating the same suspensions to 50 °C in a water-bath, or in a PCR thermal cycler. The mechanism of laser killing at 50 °C was explored by differential scanning calorimetry, by laser treatment of transparent and turbid bacterial suspensions, and by optical absorbancy studies of E. coli suspensions at 1064 nm. Taken together, the data suggested that the bactericidal action of Nd:YAG laser light at 50 °C was due partly to thermal heating and partly to an additional, as yet undefined, mechanism. Scanning electron microscopy revealed localized areas of surface damage on laser-exposed <i>E. Coli</i> cells.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Watson, Dr Ian and Nutley, Mrs Margaret and Ward, Professor Gary and Wardlaw, Prof Alastair and Stewart-Tull, Prof Duncan
• Authors: Ward, G.D., Watson, I.A., Stewart-Tull, D.E.S., Wardlaw, A.C., Wang, R.K., Nutley, M.A., and Cooper, A.
• College/School: College of Medical Veterinary and Life Sciences > School of Life Sciences; College of Science and Engineering > School of Chemistry; College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: Journal of Applied Microbiology
• Publisher: The Society for Applied Microbiology
• ISSN: 1364-5072
• ISSN (Online): 1365-2672