Gomes Thais Ferreira, Pedrosa Matheus Masalskiene, de Toledo Ana Claudia Laforga, Arnoni Veridiana Wanshi, Dos Santos Monteiro Mirian, Piai Davi Cury, Sylvestre Silvia Helena Zacarias, Ferreira Bruno
Department of Physical therapy, University Center UNIFAFIBE, Bebedouro, São Paulo, Brazil.
Study Center Collucci, Collucci's Clinical, Ribeirão Preto, São Paulo, Brazil.
Lasers Med Sci. 2018 Nov;33(8):1723-1731. doi: 10.1007/s10103-018-2528-3. Epub 2018 May 9.
The present study analyzed the bactericidal effect of methylene blue associated with low-level lasers on Escherichia coli isolated from a pressure ulcer. Microbiological material from a pressure ulcer was isolated using an aseptic swab, and antimicrobial activity was verified using the diffusion disc method. Methylene blue was used at concentrations of 0.001 and 0.005%, and low-level lasers of 670, 830, and 904 nm, with the energy densities of 4, 8, 10, and 14 J/cm, were tested on three plates each and combined with methylene blue of each concentration. In addition, three control plates were used, with each concentration and energy density separated without any interventions. The results were analyzed using the paired sample t test to determine the bactericidal effect of the methylene blue and using the ANOVA test to compare the effects of the energy densities and wavelengths among the low-level laser treatment protocols. The results showed bacterial reduction at wavelengths of 830 and 904 nm and more proliferation in wavelengths of 670 nm. In wavelength of 830 nm, a bacterial reduction was observed in the conditions with 0.001% methylene blue in all energy density utilized, with 0.005% methylene blue in energy density of 10 J/cm, and without methylene blue in energy density at 10 J/cm. And in a wavelength of 904 nm, all condition showed bacterial reduction with or without methylene blue. We concluded that the low-level lasers of 904 and 830 nm have bactericidal effects and at better energy densities (10 and 14 J/cm).
本研究分析了亚甲蓝联合低强度激光对从压疮分离出的大肠杆菌的杀菌作用。使用无菌拭子从压疮中采集微生物材料，并采用扩散平板法验证抗菌活性。亚甲蓝的使用浓度为0.001%和0.005%，对670、830和904 nm的低强度激光进行测试，能量密度分别为4、8、10和14 J/cm²，每种浓度的亚甲蓝与上述每种激光在三个平板上进行组合测试。此外，设置了三个对照平板，每种浓度和能量密度单独设置，不进行任何干预。使用配对样本t检验分析结果以确定亚甲蓝的杀菌效果，并使用方差分析比较低强度激光治疗方案中能量密度和波长的影响。结果显示，830和904 nm波长处细菌数量减少，670 nm波长处细菌增殖更多。在830 nm波长下，在所有使用的能量密度下，0.001%亚甲蓝的条件下细菌数量减少；在能量密度为10 J/cm²时，0.005%亚甲蓝条件下细菌数量减少；在能量密度为10 J/cm²时，无亚甲蓝条件下细菌数量也减少。在904 nm波长下，无论有无亚甲蓝，所有条件下细菌数量均减少。我们得出结论，904和830 nm的低强度激光具有杀菌作用，且在更好的能量密度（10和14 J/cm²）下效果更佳。
