Supression of Staphylococcus aureus growth by low intensity red laser light

Abstract

The aim of the present work was to investigate the ability of inhibiting the growth of various strains of Staphylococcus aureus by low-intensity laser light. As object of research used methicillin-sensitive and methicillinresistant strains of Staphylococcus aureus. For irradiation was used a semiconductor laser, which generates linearly polarized radiation of the red spectral region (λ - 660 nm). Power density was 100 mW/cm2, irradiation time – 5, 10, 15 and 30 min, heat density respectively 30, 60, 90, and 180 J/cm2. It was established that low-intensity laser radiation has an inhibitory effect on growth of colonies of both methicillin-sensitive and methicillin-resistant strains of Staphylococcus aureus. But resistant strain is more sensitive to the action of red light, as the bacteriostatic effect is detected at the lower doses.