EFFECT OF LOW-INTENSITY RED LASER ON GROWTH OF STAPHYLOCOCCUS AUREUS AND SENSITIZING EFFECT OF PHOTODITAZIN

Abstract

Aim. Study the effect of laser emission in the red spectrum on growth of methicillin-sensitive and methicillin-resistant strains of Staphylococcus aureus, as well as photodynamic effect of photosensitizer photoditazin. Materials and methods. Effect of light of semiconductor red laser (X 660 nm, 100 mW/cm2) at 30, 60, 90 and 180 J/cm2 on growth of S. aureus colonies was determined. Time of exposure - 5, 10, 15 and 30 minutes. In certain series of experiments bacterial cells were sensitized in advance by a water solution of photoditazin at a concentration of 5x 1 O'6 M. Results. Red laser emission was established to cause a pronouncec suppression of bacterial growth. This effect on standard S. aureus strain only took place during use of relatively high exposure doses (180 J/cm2). Photosensitivity of methicillin-resistan: strain turned out to be significantly higher: bacteriostatic effect of red light was noted alreadx at the dose of 60 J/cm2. Treatment of bacterial cells with photoditazin in advance significantly enhanced growth-inhibiting effect of laser light.

Keywords

• staphylococcus aureus
• staphylococcus aureus
• laser emission
• photoditazin