Inactivation of Proteolytic Enzymes from Porphyromonas gingivalis Using Light-activated Agents

Packer, S; Bhatti, Manpreet; Burns, T; Wilson, Michael

doi:10.1007/s101030050043

Cited by 29 publications

(30 citation statements)

References 8 publications

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“…This bacterium is also known to degrade hemoglobin for its growth to produce protoporphyrin which could act as an endogenous photosensitizer, making this bacterium photosensitive [28]. In fact, some other studies have also reported the bactericidal effects of laser irradiation on periodontopathogenic bacteria including P. gingivalis [21,23,[27][28][29][30]. These findings suggest the feasibility of PDT for both apical and marginal periodontitis.…”

Section: Introductionmentioning

confidence: 66%

“…Recently, PDT has been used as an antimicrobial therapy with some photosensitizers to target a variety of microorganisms, such as P. gingivalis, Fusobacterium nucleatum, Propionibacterium acnes, S. aureus, S. mutans, and E. coli [21][22][23][24][25][26]. Guffey and Wilborn reported that 405 nm blue light had a bactericidal effect on two aerobes, Staphylococcus aureus and Pseudomonas aeruginosa [25,26].…”

Section: Introductionmentioning

confidence: 99%

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Antibacterial and Antifungal Effect of 405 nm Monochromatic Laser on Endodontopathogenic Microorganisms

Imamura

Tatehara

Takebe

et al. 2014

International Journal of Photoenergy

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The purpose of this study is to evaluate the usefulness of 405 nm monochromatic laser irradiation as an alternative management for prevention and/or treatment of endodontic infections. A monochromatic laser-emitting device equipped with a 405-nm laser diode was developed. Using this device, the effect of 405 nm laser irradiation on the growth of Porphyromonas gingivalis, Prevotella intermedia, Enterococcus faecalis, and Candida albicans, which are microorganisms associated with persistent endodontic infections, was evaluated by viable colony counting. As a result, the irradiation with a 405 nm laser had a significant bactericidal/fungicidal effect on P. gingivalis, P. intermedia, and C. albicans, whereas the growth of E. faecalis was not affected by the irradiation. The inhibition rate in P. gingivalis and P. intermedia was ∼60% and ∼80%, respectively, following irradiation at 0.2 W for 300 sec. The inhibition rate in C. albicans was ∼90% following irradiation at 0.2 W for 1200 sec. These results indicate that 405 nm monochromatic laser irradiation exerts a bactericidal/fungicidal effect on these microorganisms. The present study clearly demonstrates that 405 nm laser irradiation is a promising alternative management strategy for prevention and/or treatment of endodontic infections.

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Section: Introductionmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 99%

Antibacterial and Antifungal Effect of 405 nm Monochromatic Laser on Endodontopathogenic Microorganisms

Imamura

Tatehara

Takebe

et al. 2014

International Journal of Photoenergy

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“…The reduction in the viable counts of P. gingivalis in pure culture at a light dose of 8.8 J was 100% (15). However, when lethal photosensitization of P. gingivalis was carried out in the presence of HGFs using unconjugated TBO, there was only a 0.7-log 10 -unit reduction in P. gingivalis viable counts but a 99% reduction in the incorporation of [ 3 H]Tdr by human cells, a measure of DNA synthesis.…”

Section: Discussionmentioning

confidence: 97%

“…Our previous work has shown that membrane proteins may be affected by lethal photosensitization, and one group of proteins affected may be the proteases of this organism. Work carried out by Packer et al showed that lethal photosensitization using TBO and HeNe laser light does indeed cause a decrease in the proteolytic activity of P. gingivalis (15). This could lead to a reduction in bacterial colonization of the oral cavity (as these proteases are involved in adhesion to host tissues) and less degradation of antibodies, cytokines, and extracellular matrix polymers.…”

Section: Discussionmentioning

confidence: 99%

Antibody-Targeted Lethal Photosensitization ofPorphyromonas gingivalis

Bhatti

MacRobert

Henderson

et al. 2000

Antimicrob Agents Chemother

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We have previously demonstrated that Porphyromonas gingivalis is susceptible to killing by toluidine blue O (TBO) when irradiated with light from a helium-neon (HeNe) laser. The aim of this study was to determine whether a TBO-antibody conjugate (Ab-TBO) could be used to specifically target P. gingivalis to lethal photosensitization in the presence of Streptococcus sanguis or human gingival fibroblasts (HGFs). When a mixture of P. gingivalis and S. sanguis was exposed to 4 g of TBO/ml and irradiated with HeNe laser light, there were 1.5-and 4.0-log 10 -unit reductions in the viable counts, respectively. In contrast, when TBO was conjugated with a murine monoclonal antibody against P. gingivalis lipopolysaccharide, the reductions in viable counts of P. gingivalis and S. sanguis amounted to 5.0 and 0.1 log 10 units, respectively. Lethal photosensitization of P. gingivalis in the presence of HGFs using unconjugated TBO resulted in a 0.7-log 10 -unit reduction in P. gingivalis viable counts and a 99% reduction in the incorporation of tritiated thymidine ([ 3 H]Tdr) by the HGFs. In contrast, when the Ab-TBO conjugate was used, there was a 100% reduction in P. gingivalis viable counts but no significant reduction in the incorporation of [ 3 H]Tdr by HGFs. These results demonstrate that specific targeting of P. gingivalis can be achieved using TBO conjugated to a monoclonal antibody raised against a cell surface component of this organism.

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“…Although PDT is more widely known for its application to the treatment of neoplasms, there is also interest in antimicrobial PDT, as a large number of microorganisms (including oral species) have been reported to be killed in vitro by this approach (21,27,31,40,43,46,47). Furthermore, the potencies of some key virulence factors (lipopolysaccharide and proteases) have also been shown to be reduced by photosensitization (18,32). Due to its localized and noninvasive nature, the side effects associated with many antibiotics (e.g., gastrointestinal disturbance) are unlikely to occur with PDT.…”

mentioning

confidence: 99%

In Vivo Killing of Porphyromonas gingivalis by Toluidine Blue-Mediated Photosensitization in an Animal Model

Kömerik

Nakanishi

MacRobert

et al. 2003

Antimicrob Agents Chemother

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294

228

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Porphyromonas gingivalis is one of the major causative organisms of periodontitis and has been shown to be susceptible to toluidine blue-mediated photosensitization in vitro. The aims of the present study were to determine whether this technique could be used to kill the organism in the oral cavities of rats and whether this would result in a reduction in the alveolar bone loss characteristic of periodontitis. The maxillary molars of rats were inoculated with P. gingivalis and exposed to up to 48 J of 630-nm laser light in the presence of toluidine blue. The number of surviving bacteria was then determined, and the periodontal structures were examined for evidence of any damage. When toluidine blue was used together with laser light there was a significant reduction in the number of viable P. gingivalis organisms. No viable bacteria could be detected when 1 mg of toluidine blue per ml was used in conjunction with all light doses used. On histological examination, no adverse effect of photosensitization on the adjacent tissues was observed. In a further group of animals, after time was allowed for the disease to develop in controls, the rats were killed and the level of maxillary molar alveolar bone was assessed. The bone loss in the animals treated with light and toluidine blue was found to be significantly less than that in the control groups. The results of this study show that toluidine blue-mediated lethal photosensitization of P. gingivalis is possible in vivo and that this results in decreased bone loss. These findings suggest that photodynamic therapy may be useful as an alternative approach for the antimicrobial treatment of periodontitis.

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Inactivation of Proteolytic Enzymes from Porphyromonas gingivalis Using Light-activated Agents

Cited by 29 publications

References 8 publications

Antibacterial and Antifungal Effect of 405 nm Monochromatic Laser on Endodontopathogenic Microorganisms

Antibacterial and Antifungal Effect of 405 nm Monochromatic Laser on Endodontopathogenic Microorganisms

Antibody-Targeted Lethal Photosensitization ofPorphyromonas gingivalis

In Vivo Killing of Porphyromonas gingivalis by Toluidine Blue-Mediated Photosensitization in an Animal Model

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