RESUMO
AIM: Study the effect of 1270 nm wavelength laser exposure on the viability of Staphylococcus aureus and S. epidermidis cells in vitro. MATERIALS AND METHODS: Reference strain S. aureus 209P and clinical isolate S. epidermidis 26/193 that form bacterial biofilm were used in the study. Ica gene presence in S. epidermidis 26/193 that controls biofilm formation was confirmed in the study by PCR with a primer that generates a specific 814 n.p. amplicon. Experimental device by "New surgical technologies, Ltd." was used as a source of emission. The device has a continuous emission mode of laser semiconductor diodes with 1270 nm wavelength. Maximum regulated power of the emission is up to 3 W. Emission power in the studies performed was 150 mW. The time of exposition was 5, 10, 15 and 30 minutes. The amount of viable cells in the experiment and control was determined by calculating CFU/ml. Evaluation of bacterial biofilm formation was performed by the method described in O'Toole G.A. et al. (2000). RESULTS: A decrease of the number of viable forms of S. aureus 209P by a mean of 52 +/- 6.0% and 76 +/- 4.0%, and of S. epidermidis 26/193 by a mean of 48 +/- 4% and 64 +/- 5% for 15 and 30 min exposition, respectively, and a significant suppression of biofilm formation by staphylococci was shown. CONCLUSION: Exposure to 1270 nm laser renders a moderate bactericidal effect on staphylococci cells and significantly suppresses their bacterial biofilm formation.
