Lethal photosensitization of wound-associated microbes using indocyanine green and near-infrared light

Omar, Ghada Said Mohammed; Wilson, Michael; Nair, Sean P.

doi:10.1186/1471-2180-8-111

Cited by 88 publications

(60 citation statements)

References 57 publications

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“…Additionally, light sources should be inexpensive, lightweight and highly flexible (Konopka & Goslinski, 2007). Despite the fact that the antimicrobial activity of LED light sources has been intensively investigated in various studies (Omar et al, 2008;Omar, 2010), the efficacy of visible light in combination with water-filtered infrared-A (VIS+wIRA) in killing bacteria has not previously been examined. This combination delivers a broad-band light source which could be used in combination with different photosensitizers.…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial photodynamic therapy using visible light plus water-filtered infrared-A (wIRA)

Al‐Ahmad

Tennert

Karygianni

et al. 2013

Journal of Medical Microbiology

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The aim of this study was to investigate the effectiveness of antimicrobial photodynamic therapy (APDT) using visible light together with water-filtered infrared-A (VIS+wIRA) to eradicate single species of planktonic bacteria and micro-organisms during initial oral bacterial colonization in situ. A broadband VIS+wIRA radiator with a water-filtered spectrum in the range 580-1400 nm was used for irradiation. Toluidine blue (TB) was utilized as a photosensitizer at concentrations of 5, 10, 25 and 50 mg ml "1 . The unweighted (absolute) irradiance was 200 mW cm "2 and it was applied for 1 min. Planktonic cultures of Streptococcus mutans and Enterococcus faecalis were treated with APDT. Salivary bacteria harvested by centrifugation of native human saliva were also tested. In addition, initial bacterial colonization of bovine enamel slabs carried in the mouths of six healthy volunteers was treated in the same way. Up to 2 log 10 of S. mutans and E. faecalis were killed by APDT. Salivary bacteria were eliminated to a higher extent of 3.7-5 log 10 . All TB concentrations tested proved to be highly effective. The killing rate of bacteria in the initial oral bacterial colonization was significant (P50.004) at all tested TB concentrations, despite the interindividual variations found among study participants. This study has shown that APDT in combination with TB and VIS+wIRA is a promising method for killing bacteria during initial oral colonization. Taking the healing effects of wIRA on human tissue into consideration, this technique could be helpful in the treatment of peri-implantitis and periodontitis. INTRODUCTIONAlthough photodynamic therapy (PDT) is currently being applied in cancer cell elimination (Allison & Sibata, 2010;Ericson et al., 2008), more attention has been paid to its application in antimicrobial treatment (Wood et al., 2006;Donnelly et al., 2007;Maisch, 2007). Due to the growing number of antibiotic-resistant micro-organisms, research is focusing on PDT as an alternative chemotherapy modality (Garcez et al., 2010;Kharkwal et al., 2011). Since PDT causes damage to different parts of microbial cells and affects different interaction pathways in the micro-organisms, the development of antibiotic resistance against PDT can be excluded (Wainwright et al., 2010).PDT impresses with its excellent target-cell specificity and high efficiency. The photodynamic effect requires a photosensitizer, suitable light and oxygen. The photosensitizer can be transferred to the high-energy triplet state and reacts with oxygen, producing singlet oxygen and other radical species which themselves cause increased target cell damage (Konopka & Goslinski, 2007). The photosensitizer should be non-toxic and show antimicrobial activity only after activation by illumination. In addition it should not be bio-destructible. Light sources used in PDT should produce low-power visible light at a specific wavelength (or range of wavelengths) which itself does not harm human tissues in the absence of the photosensitizer. Additionally, light s...

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Section: Introductionmentioning

confidence: 99%

Antimicrobial photodynamic therapy using visible light plus water-filtered infrared-A (wIRA)

Al‐Ahmad

Tennert

Karygianni

et al. 2013

Journal of Medical Microbiology

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“…Candida albicans was the most common species isolated from oral lesions/swabs of HIV positive patients accounting for 50% (2) of total 4 oral swabs. In previous studies done by Dunic et al, (2004), Mrudula Patel et al, (2006), Omar et al, (2008) C. albicans was the most common species isolated in oral swabs of HIV positive patients in the percentage of 77.7%, 83.5%, 78.6% and 84.5% respectively. Percentage of NAC spp.…”

Section: Image3 Candida Albicans (Apple Green) Candida Dubliniensis mentioning

confidence: 81%

Isolation, Speciation and Characterization of Candida Species in Clinical Isolates

Sharma¹

2017

Int.J.Curr.Microbiol.App.Sci

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“…removing the biofilm shield with a SW laser gave way to the next step which is killing the biofilm 4 . It was already shown that low level diode laser can take an active role in photodynamic therapy with as high as 99.9% killing rate possible after enhancing with a photosensitizer as shown by Wilson 5 . Thus laser-generated shockwave exposed the bacteria to a floating state, thus enabling a second strike.…”

Section: Laser Disruption and Killing Of Mrsa Biofilmsmentioning

confidence: 97%

Laser disruption and killing of mrsa biofilms

Krespi¹,

Kizhner²,

Nistico³

et al. 2009

The Laryngoscope

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Objective: To study the efficacy of two different lasers in vitro, in disrupting biofilm and killing planktonic pathogenic bacteria. Materials and Methods:Biofilms of S. aureus Xen 31, a stable bioluminescent clinical MRSA construct, were grown in a 96 well microtiter plate for three days. The study included seven arms; a) control, b) ciprofloxacin (0.3 mg/L,) alone, c) SW laser alone, d) NIR laser alone e) SW laser and ciprofloxacin, f) SW and NIR lasers, g) SW, NIR lasers and ciprofloxacin. The results were evaluated with an IVIS biophotonic system (for live bacteria) and optical density (for total bacteria).Results: With no antibiotics there was a 43% reduction in OD (P<0.05) caused by the combination of SW and NIR suggesting that biofilm had been disrupted. There was an 88% reduction (P<0.05) in live biofilm. Ciprofloxacin alone resulted in a decrease of 28% of total live cells (biofilm remaining attached and disrupted planktonic cells) and 58% of biofilm cells (both P>0.05). Ciprofloxacin in combination with SW and SW + NIR lasers caused a decrease of over 60% in total live biomass and over 80% of biofilm cells, which was significantly greater than ciprofloxacin alone (P<0.05). Conclusions: SW and NIRLaser combination is a powerful alternative for control or eradication of MRSA biofilms. The reduction in bacteria for the different arms using OD and IVIS respectively are as follows b-44%,58%, c-15%, 8%, d-20% increase, e-79%, 81% (P<0.05), f-43%, 88% (P<0.05), e-81%, 85% (P<0.05). Parenthesis show only statistically significant results. LASER DISRUPTION AND KILLING OF MRSA BIOFILMSBiofilms are emerging as an integral part of CRS pathology. Bacteria in biofilm communities display significantly greater resistance to traditional antimicrobial therapies than their planktonic counterparts. Current therapies targeting biofilms are multiple. Some are merely mechanical while other use combination therapy trying to enhance antimicrobial treatment. A previous successful study of disrupting biofilm i.e. removing the biofilm shield with a SW laser gave way to the next step which is killing the biofilm 4 . It was already shown that low level diode laser can take an active role in photodynamic therapy with as high as 99.9% killing rate possible after enhancing with a photosensitizer as shown by Wilson 5 . Thus laser-generated shockwave exposed the bacteria to a floating state, thus enabling a second strike. The second strike was inflicted by a diode laser with 940nm wave length with several arms enhanced by cipro. Arms that contained diode followed by the shockwave or either laser alone were not of significant killing power.A possible explanation for the slight significance of ciprofloxacin containing arm versus the laser only arm is temperature rise over 44C°rendering the antibiotic less active. The temperature rise may be a possible explanation for the bactericidal effect of the laser as shown by Yeo previously 6 .Several limitations to our current study are using in vitro model that does not predict biofilm formation i...

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Lethal photosensitization of wound-associated microbes using indocyanine green and near-infrared light

Cited by 88 publications

References 57 publications

Antimicrobial photodynamic therapy using visible light plus water-filtered infrared-A (wIRA)

Antimicrobial photodynamic therapy using visible light plus water-filtered infrared-A (wIRA)

Isolation, Speciation and Characterization of Candida Species in Clinical Isolates

Laser disruption and killing of mrsa biofilms

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