Red and infrared laser therapy inhibits in vitro growth of major bacterial species that commonly colonize skin ulcers

Author(s)

Alves de Sousa, Natanael Teixeira ^[1] ; Gomes, Rosana Caetano ^[1] ; Santos, Marcos Ferracioli ^[2] ; Brandino, Hugo Evangelista ^[1] ; Martinez, Roberto ^[3] ; de Jesus Guirro, Rinaldo Roberto ^{[1, 2, 4]}

Affiliation

^[1] Univ Sao Paulo, Ribeirao Preto Sch Med, Postgrad Program Rehabil & Funct Performance, Dept Biomech Med & Rehabil Locomotor Apparatus, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Ribeirao Preto Sch Med, Dept Biomech Med & Rehabil Locomotor Apparatus, Grad Course Physiotherapy, BR-14049900 Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo, Ribeirao Preto Sch Med, Dept Internal Med, Div Infect Dis, BR-14049900 Ribeirao Preto, SP - Brazil

^[4] Univ Sao Paulo, Ribeirao Preto Sch Med, Dept Biomech Med & Rehabil Locomotor Syst, 3900 Bandeirantes Ave, BR-14049900 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: Lasers in Medical Science; v. 31, n. 3, p. 549-556, APR 2016.
• Web of Science Citations: 8

Abstract

Low-level laser therapy (LLLT) is used in chronic wounds due to its healing effects. However, bacterial species may colonize these wounds and the optimal parameters for effective bacterial inhibition are not clear. The aim of this study was to analyze the effect of LLLT on bacterial growth in vitro. Bacterial strains including Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were suspended in saline solution at a concentration of 10(3) cells/ml and exposed to laser irradiation at wavelengths of 660, 830, and 904 nm at fluences of 0 (control), 3, 6, 12, 18, and 24 J/cm(2). An aliquot of the irradiated suspension was spread on the surface of petri plates and incubated at 37 A degrees C for quantification of colony-forming unit after 24, 48, and 72 h. Laser irradiation inhibited the growth of S. aureus at all wavelengths and fluences higher than 12 J/cm(2), showing a strong correlation between increase in fluence and bacterial inhibition. However, for P. aeruginosa, LLLT inhibited growth at all wavelengths only at a fluence of 24 J/cm(2). E. coli had similar growth inhibition at a wavelength of 830 nm at fluences of 3, 6, 12, and 24 J/cm(2). At wavelengths of 660 and 904 nm, growth inhibition was only observed at fluences of 12 and 18 J/cm(2), respectively. LLLT inhibited bacterial growth at all wavelengths, for a maximum of 72 h after irradiation, indicating a correlation between bacterial species, fluence, and wavelength. (AU)

• FAPESP's process: 11/22170-0 - The effect of low level laser therapy in the spectra of visible and infrared light, diphasic current, high voltage in culture of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli strains in vitro
• Grantee: Rinaldo Roberto de Jesus Guirro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/02974-2 - The effect of low level laser therapy in the spectra of visible and infrared light in a culture of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli strains in vitro
• Grantee: Marcos Ferracioli Santos
• Support Opportunities: Scholarships in Brazil - Scientific Initiation