Laser irradiation effect on Staphylococcus aureus and Pseudomonas aeruginosa biofilms isolated from venous leg ulcer (original) (raw)
Related papers
Effects of low intensity laser in in vitro bacterial culture and in vivo infected wounds
Revista do Colégio Brasileiro de Cirurgiões, 2014
Effects of low intensity laser in in vitro bacterial culture and in vivo infected wounds 49 Rev. Col. Bras. Cir. 2014; 41(1): 049-055 ABSTRACT ABSTRACT ABSTRACT ABSTRACT ABSTRACT Objective Objective Objective Objective Objective: to compare the effects of low intensity laser therapy on in vitro bacterial growth and in vivo in infected wounds, and to analyze the effectiveness of the AsGa Laser technology in in vivo wound infections. Methods
Journal of Clinical Laser Medicine & Surgery, 2002
Objective: To examine the effects of low-intensity laser therapy (LILT) on bacterial growth in vitro. Background Data: LILT is undergoing investigation as a treatment for accelerating healing of open wounds. The potential of coincident effects on wound bacteria has received little attention. Increased bacterial proliferation could further delay recovery; conversely inhibition could be beneficial. Materials and Methods: Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus were plated on agar and then irradiated with wavelengths of 630, 660, 810, and 905 nm (0.015 W/cm 2) and radiant exposures of 1-50 J/cm 2. In addition, E. coli was irradiated with 810 nm at an irradiance of 0.03 W/cm 2 (1-50 J/cm 2). Cells were counted after 20 h of incubation post LILT. Repeated measures ANOVA and Tukey adjusted post hoc tests were used for analysis. Results: There were interactions between wavelength and species (p = 0.0001) and between wavelength and radiant exposure (p = 0.007) in the overall effects on bacterial growth; therefore, individual wavelengths were analyzed. Over all types of bacteria, there were overall growth effects using 810-and 630-nm lasers, with species differences at 630 nm. Effects occurred at low radiant exposures (1-20 J/cm 2). Overall effects were marginal using 660 nm and negative at 905 nm. Inhibition of P. aeruginosa followed irradiation using 810 nm at 5 J/cm 2 (223%; p = 0.02). Irradiation using 630 nm at 1 J/cm 2 inhibited P. aeruginosa and E. coli (227%). Irradiation using 810 nm (0.015 W/cm 2) increased E. coli growth, but with increased irradiance (0.03 W/cm 2) the growth was significant (p = 0.04), reaching 30% at 20 J/cm 2 (p = 0.01). S. aureus growth increased 27% following 905-nm irradiation at 50 J/cm 2. Conclusion: LILT applied to wounds, delivering commonly used wavelengths and radiant exposures in the range of 1-20 J/cm 2 , could produce changes in bacterial growth of considerable importance for wound healing. A wavelength of 630 nm appeared to be most commonly associated with bacterial inhibition. The findings of this study might be useful as a basis for selecting LILT for infected wounds.
Journal of Clinical Laser Medicine & Surgery, 2002
Objective: To examine the effects of low-intensity laser therapy (LILT) on bacterial growth in vitro. Background Data: LILT is undergoing investigation as a treatment for accelerating healing of open wounds. The potential of coincident effects on wound bacteria has received little attention. Increased bacterial proliferation could further delay recovery; conversely inhibition could be beneficial. Materials and Methods: Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus were plated on agar and then irradiated with wavelengths of 630, 660, 810, and 905 nm (0.015 W/cm 2) and radiant exposures of 1-50 J/cm 2. In addition, E. coli was irradiated with 810 nm at an irradiance of 0.03 W/cm 2 (1-50 J/cm 2). Cells were counted after 20 h of incubation post LILT. Repeated measures ANOVA and Tukey adjusted post hoc tests were used for analysis. Results: There were interactions between wavelength and species (p = 0.0001) and between wavelength and radiant exposure (p = 0.007) in the overall effects on bacterial growth; therefore, individual wavelengths were analyzed. Over all types of bacteria, there were overall growth effects using 810-and 630-nm lasers, with species differences at 630 nm. Effects occurred at low radiant exposures (1-20 J/cm 2). Overall effects were marginal using 660 nm and negative at 905 nm. Inhibition of P. aeruginosa followed irradiation using 810 nm at 5 J/cm 2 (223%; p = 0.02). Irradiation using 630 nm at 1 J/cm 2 inhibited P. aeruginosa and E. coli (227%). Irradiation using 810 nm (0.015 W/cm 2) increased E. coli growth, but with increased irradiance (0.03 W/cm 2) the growth was significant (p = 0.04), reaching 30% at 20 J/cm 2 (p = 0.01). S. aureus growth increased 27% following 905-nm irradiation at 50 J/cm 2. Conclusion: LILT applied to wounds, delivering commonly used wavelengths and radiant exposures in the range of 1-20 J/cm 2 , could produce changes in bacterial growth of considerable importance for wound healing. A wavelength of 630 nm appeared to be most commonly associated with bacterial inhibition. The findings of this study might be useful as a basis for selecting LILT for infected wounds.
Photomedicine and laser surgery, 2011
Aim: We aimed to assess the use of two wavelengths on the healing of infected wounds. Background: Infection is the most significant cause of impaired wound repair or healing. Several therapeutic approaches are used for improving wound healing including the use of different light sources, such as the laser. Some wavelengths yield positive photobiological effects on the healing process. Material and Methods: The backs of 24 young adult male Wistar rats under general anesthesia were shaved and cleaned, and a 1 by 1 cm cutaneous wound was created with a scalpel and left untreated. The wounds were infected with Staphylococcus aureus, and the rats were randomly divided into two sets of four subgroups with three animals in each subgroup: control, red laser light, infrared laser light, and red þ infrared laser light. Laser phototherapy was carried out with a diode [l680 nm/ 790 nm, power (P) ¼ 30 mW/40 mW, continuous wave laser, Ø ¼ 3 mm, power density (P) ¼ 424 and 566 mW/ cm 2 , time ¼ 11.8/8.8 sec, E ¼ 0.35 J] and started immediately after surgery and repeated every other day for 7 d. Laser light was applied on four points around the wounded area (5 J/cm 2 ). The animals were killed either 8 or 15 d after contamination. Specimens were taken, embedded in paraffin, and sectioned and stained for histological analysis. Results: Histological analysis showed that control subjects had a lower amount of blood vessels when compared with irradiated subjects. Irradiated subjects had more advanced resolution of inflammation compared with controls. Irradiated subjects also showed a more intense expression of the collagen matrix. The collagen fibers were mostly mature and well organized in these subjects at the end of the experimental time especially when both wavelengths were used. Conclusion: The results of the present study indicate that laser phototherapy has a positive effect on the healing of infected wounds, particularly with the association of l680 þ l790 nm.
Infectious Disease Reports
Biofilms are able to casue microorganisms to be 80% more resistant to antibiotics. The extracelullar polymeric substance (EPS) in biofilm functions to protect bacteria, making it difficult for antibiotics to penetrate the biofilm layer. This study aims to determine the effective- ness of photodynamic inactivation with blue diode laser to reduce Staphylococcus aureus biofilm at various ages of biofilms. The light source is a 403 nm blue diode laser with an energy power of about 27.65±0.01 mW. The study was designed with two groups: Group C was the untreated control group with variations in age of biofilms (0; 6; 11; 17; 24; 32; 40 and 48) hours; Group T was a laser treatment group with variations in age of biofilm and energy density (4.23; 8.46; 12.70; 16.93 and 21.16) J/cm2. Biofilm reduction measurement method using ELISA test was performed to calculate OD595 value. The statistical analysis results of variance showed that there was an influence of biofilm age and irradiation energy...
Low laser therapy (photobiomodulation) on bacteria of pressure ulcers: in vitro studies
Fisioterapia Brasil
The biological effects promoted by low power laser result in faster wound healing. However, wounds are very complex systems from both host and microbial point of view. Since infection is a common cause of delayed wound healing, it is important to understand the effect of low-level laser therapy in bacterial growth. This mini-review summaries the current evidence about effects of low level laser on bacteria vitro studies.Key-words: Low power laser, infected injury, bacteria.
Anais Brasileiros de Dermatologia, 2013
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/cm 2 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. RESULTS: The statistical analysis of median values showed that the groups submitted to laser treatment had low bacterial proliferation. CONCLUSION: The laser (AlGaInP), with a dose of 5J/cm 2 in both intact skin and in wounds of rats infected with Staphylococcus aureus MRSA, is shown to reduce bacterial proliferation.
Lasers in Medical Science, 2020
We investigated the influence of femtosecond laser irradiation on the growth of the two most common infectious bacterial pathogens in wounds; Staphylococcus aureus and Pseudomonas aeruginosa as an attempt to validate optimum parameters for a laser-based bactericidal modality to be used clinically. Bacterial cultures were exposed to femtosecond laser irradiation at different wavelengths, exposure times, and laser powers. The source of femtosecond laser was INSPIRE HF100 laser system, Spectra-Physics, which is pumped by a mode-locked femtosecond Ti: sapphire laser MAI TAI HP, Spectra-Physics. After irradiation, bacterial cells' survival was monitored by observing the clear zones of inhibition in cultured agar plates. Results for all strains indicated that the exposure to femtosecond laser irradiation with a wavelength ranging from ultraviolet (λ > 350 nm) to blue laser light (λ < 480 nm), for a period above 20 min and with a power density of ≈ 0.063 W/cm 2 , was enough to inhibit both bacterial pathogens with the results maintained for 1 week following irradiation.
2010
Abstrac:t This study has been explored to cope determine whether continues diode laser with 805nm wavelength was able to affect the potency of bacterial production of virulence factors (alkaline protease ,hemolytic and pyocyanin),and susceptibility MIC of five antimicrobial agents (imipenem,ciprofloxacin,piperacillin,gentamicin and amikacin).The samples collected from 75 patients suffering from sever burn-wounds infections from burn units in Al-Kendy teaching hospital (Baghdad, Iraq) for a period of six month from (May 2009-November 2009). Samples were collected, stored and processed using standard laboratory procedures.Thirty five isolates of Pseudomonas aeruginosa bacteria were obtained depending on morphological and biochemical tests. Culture supernatant of three selected isolates of Pseudomonas aeruginosa were exposed to diod laser 805nm and 7.07W/cm for (1,3and5) minutes .The activity of bacteria to produce virulence factors and its susceptibility to antimicrobial agents minimu...
Journal of Physical Therapy Science, 2021
The aim of this study was to evaluate the effect of high-power Nd:YAG laser on Staphylococcus aureus and Pseudomonas aeruginosa bacterial growth. [Materials and Methods] Seven samples of S. aureus and seven samples of P. aeruginosa were prepared in the microbiology lab, one used as a control sample and the remaining six samples used as experimental samples, which were irradiated by a high-power laser (LASERSIX ME, 15W) with a total dose of 500 and 700 J. The primary measure was the semi-qualitative assessment of turbidity and bacterial count; the turbidity was assessed 24 h after laser application. [Results] There was a significant decrease in turbidity in all experimental samples of S. aureus and P. aeruginosa after 24 h of high-power laser application for 500 and 700 J and a significant decrease in the colony-forming unit (CFU) value in both types, and there were no significant differences in turbidity and CFU when comparing 500 and 700 J. [Conclusion] A high power Nd:YAG laser was found to be an effective modality for inhibition of S. aureus and P. aeruginosa growth.