Journal of microbiology, epidemiology and immunobiologyJournal of microbiology, epidemiology and immunobiology0372-93112686-7613Central Research Institute for Epidemiology13910.36233/0372-9311-2017-2-34-37EFFECT OF LOW-INTENSITY RED LASER ON GROWTH OF STAPHYLOCOCCUS AUREUS AND SENSITIZING EFFECT OF PHOTODITAZINBrilG. E.noemail@neicon.ruEgorovaA. V.noemail@neicon.ruBugaevaI. O.noemail@neicon.ruPonomarevG. V.noemail@neicon.ruRazumovsky Saratov State Medical UniversityOrekhovich Institute of Biomedical Chemistry28042017942343710042019Copyright © 2017, Bril G.E., Egorova A.V., Bugaeva I.O., Ponomarev G.V.2017Aim. 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/cm<sup>2</sup>) at 30, 60, 90 and 180 J/cm<sup>2</sup> 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'<sup>6</sup> 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/cm<sup>2</sup>). 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/cm<sup>2</sup>. Treatment of bacterial cells with photoditazin in advance significantly enhanced growth-inhibiting effect of laser light.Staphylococcus aureusStaphylococcus aureuslaser emissionphotoditazinлазерное излучениефотодитазин[Braga E.D., Aguiar-Alves Е, de Freitas M.F. et al. High prevalence of Staphylococcus aureus and methicillin-resistant S. aureus colonization among healthy children attending public daycare centers in informal settlements in a large urban center in Brazil. BMC Infect. Dis. 2014, 6 (14): 538.][Carrel М., Schweizer M.L., Sarrazin M.V. et al. Residential proximity to large numbers of swine in feeding operations is associated with increased risk of methicillin-resistant Staphylococcus aureus colonization at time of hospital admission in rural Iowa veterans. Infect. Control. Hosp. Epidemiol. 2014, 35 (2): 190-193.][Dissemond J., Goos М., Esser S. Pathogenetic significance of methicillin resistant Staphylococcus aureus (MRSA) in chronic wounds. Vasa. 2003, 32 (3): 131-138.][McKinnell J.A., Miller L.G., Eells S.J. et al. A systematic literature review and metaanalysis of factors associated with methicillin-resistant Staphylococcus aureus colonization at time of hospital or intensive care unit admission. Infect. Control. Hosp. Epidemiol. 2013,34(10): 1077-1086.][Miller R.M., Price J.R., Batty E.M. et al. Healthcare-associated outbreak of meticillin-resistant Staphylococcus aureus bacteraemia: role of a cryptic variant of an epidemic clone. J. Hosp. Infect. 2014, 86 (2): 83-89.]