Low level laser therapy (AlGaInP) applied at 5J/cm 2 reduces the proliferation of Staphylococcus aureus MRSA in infected wounds and intact skin of rats * Laser de baixa intensidade (AlGaInP) aplicado com 5J/cm 2 reduz a proliferação de Staphilococcus aureus MRSA em feridas infectadas e em pele íntegra de ratos

BACKGROUND: Laser therapy is a low cost, non-invasive procedure with good healing results. Doubts exist as to whether laser therapy action on microorganisms can justify research aimed at investigating its possible effects on bacteria-infected wounds. OBJECTIVE: To assess the effect of low intensity laser on the rate of bacterial contamination in infected wounds in the skin of rats. METHODS: An experimental study using 56 male Wistar rats. The animals were randomly divided into eight groups of seven each. Those in the "infected" groups were infected by Staphylococcus aureus MRSA in the dorsal region. Red laser diode (AlGaInP) 658nm, 5J/cm2 was used to treat the animals in the "treated" groups in scan for 3 consecutive days. Samples were drawn before inoculating bacteria and following laser treatment. For statistical analysis we used the nonparametric Wilcoxon (paired data) method with a significance level of p <0.05. R ESULTS: The statistical analysis of median values showed that the groups submitted to laser treatment had low bacterial pro- liferation. CONCLUSION: The laser (AlGaInP), with a dose of 5J/cm2 in both intact skin and in wounds of rats infected with Staphylococcus