Photodynamic inactivation of planktonic cultures of Streptococcus mutans using erythrosine irradiated by LED / Inativação fotodinâmica de culturas planctônicas de Streptococcus mutans usando eritrosina irradiada por LED

Objective: The aim of this in vitro study was to evaluate the efficacy of photodynamic inactivation (PDI) with erythrosine (E), using a light-emitting diode (LED) on planktonic cultures of Streptococcus mutans. Material and Methods: A Streptococcus mutans strain (UA 159) was used to prepare the suspensions containing 107 cells/mL, which was tested under different experimental conditions: a) LED irradiation in the presence of erythrosine as a photosensitizer (E+L+); b) LED irradiation only (P-L+); c) treatment with erythrosine only (E+L-); and d) no LED irradiation or photosensitizer (P) treatment, which served as a control group (P-L-). After treatment, strains were seeded onto MSBS agar for determination of the number of colony-forming units (CFU/mL). Results: The results were submitted to analysis of variance and the Tukey test (p < 0.05). No reduction in the number of CFU/mL was observed in the treatment group with erythrosine (E+L+) when compared to the control (P-L-). Conclusion: PDI using erythrosine did not reduce the number of CFUs per millimeter within the parameters in this study. (AU)

Objetivo: o objetivo deste estudo in vitro foi avaliar a eficácia da inativação fotodinâmica (PDI) com a eritrosina (E), usando diodo de emissão de luz azul (LED) em culturas planctônicas de Streptococcus mutans. Material e métodos: a cepa de Streptococcus mutans (UA 159) foi usada para o preparo das suspensões padrões contendo 107 células/mL, as quais foram testadas em diferentes condições experimentais a) irradiação com LED em presença da eritrosina como fotossensibilizador (E+L+); b) irradiação com LED apenas (F-L+); c) tratamento com eritrosina apenas (E+L-); e d) tratamento sem irradiação com LED ou fotossensibilizador (F), que serviu como grupo controle (F-L-). Após o tratamento, as cepas foram semeadas em ágar MSBS para determinação do número de unidades formadoras de colônias (UFC/mL). Resultados: os resultados foram submetidos à análise de variância e teste de Tukey (p < 0.05). Não foi observada redução no número de UFC/mL no grupo de tratamento com eritrosina (E+L+) quando comparado ao grupo controle (F-L-). Conclusão: a PDI usando etritrosina e LED não reduziu o número de UFCs por milímetro com os parâmetros utilizados neste estudo.(AU)

The Effect of Some Synthetic Food Colorants on Selected Biochemical Indices of Male Wistar Rats

The aim is to evaluate the effect of tartrazine and erythrosine on serum glucose, cholesterol and triglycerides. A total of 20 adult male Wistar rats were divided into five groups with 4 rats per group. Group 1 served as the control and was given only water and feed. Whereas group 2, 3, 4, 5 were administered 5 mg/kgb.wt, 10 mg/kgb.wt, 20 mg/kgb.wt, 40 mg/kgb.wt of Tartrazine and Erythrosine via orogastric feeding for 21 days. At the end of 21 days, blood samples were collected via ocular puncture and used to measure glucose, cholesterol and triglyceride concentration in the serum of the animals. The results were analyzed using One way ANOVA, followed by post hoc multiple comparisons and level of significance set at p<0.05. The result revealed that there was a significant difference p<0.05 in the mean glucose concentration of Group 4 (5.81±0.40 mmol/L) and Group 5 (5.28±0.25 mmol/L) when compared with the control (3.27±0.11 mmol/L). Although Group 4 showed a higher mean cholesterol concentration (0.92±0.27 mmol/L) when compared with the control (0.18±0.05 mmol/L) the difference was not significant p>0.05. Furthermore, Group 5 showed no significant mean triglyceride concentration (2.01±0.15 mmol/L) when compared with the control (2.95±0.04 mmol/L). This result revealed that the colourants increased the glucose and cholesterol levels in the test group in a dose-dependent manner. The increase in serum glucose concentration may be an indication of pancreatic cancer caused by the hydrocarbons contained in the colourants.

Susceptibility of Mutans streptococci in the Planktonic and Biofilm State to Erythrosine / 대한소아치과학회지

The aim of this study was to investigate the susceptibility of Mutans streptococci in both planktonic and biofilm states to erythrosine.S. mutans was cultured in brain-heart infusion (BHI) broth. Erythrosine was diluted in BHI broth and prepared at a concentration range of 0.02 – 10000 µg/L. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured using the microdilution method. After forming biofilms on 96-well plates, the minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC) were measured.S. mutans was susceptible to erythrosine in both planktonic and biofilm states. MIC and MBC values were both 19.5 µg/L for the planktonic state, while MBIC and MBEC values were 313 µg/L and 2500 µg/L, respectively, for the biofilm state.Erythrosine (19.5 µg/L) exhibited a bactericidal effect on S. mutans (killing 99.9%) in the planktonic state. For biofilms, erythrosine inhibited biofilm growth and eradicated 99.9% of biofilm bacteria at higher concentrations than MIC and MBC. These MBIC and MBEC concentrations are much lower than known noxious doses, and the MIC, MBC, and MBIC values were even lower than clinical concentrations.

Antimicrobial effect of toothbrush with light emitting diode on dental biofilm attached to zirconia surface: an in vitro study

PURPOSE: The purpose of this study was to evaluate the antimicrobial effects of a toothbrush with light-emitting diodes (LEDs) on periodontitis-associated dental biofilm attached to a zirconia surface by static and dynamic methods. MATERIALS AND METHODS: Zirconia disks (12 mm diameter, 2.5 mm thickness) were inserted into a 24-well plate (static method) or inside a Center for Disease Control and Prevention (CDC) biofilm reactor (dynamic method) to form dental biofilms using Streptococcus gordonii and Fusobacterium nucleatum. The disks with biofilm were subdivided into five treatment groups-control, commercial photodynamic therapy (PDT), toothbrush alone (B), brush with LED (BL), and brush with LED+erythrosine (BLE). After treatment, the disks were agitated to detach the bacteria, and the resulting solutions were spread directly on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy (SEM) was performed to visualize alterations in bacterial morphology. RESULTS: No significant difference in biofilm formation was observed between dynamic and static methods. A significant difference was observed in the number of viable bacteria between the control and all experimental groups (P < 0.05). The percentage of bacterial reduction in the BLE group was significantly higher than in the other treated groups (P < 0.05). SEM revealed damaged bacterial cell walls in the PDT, BL, and BLE groups, but intact cell walls in the control and B groups. CONCLUSION: The findings suggest that an LED toothbrush with erythrosine is more effective than other treatments in reducing the viability of periodontitis-associated bacteria attached to zirconia in vitro.

Efficacy of an LED toothbrush on a Porphyromonas gingivalis biofilm on a sandblasted and acid-etched titanium surface: an in vitro study

PURPOSE: The aim of this study was to evaluate the antimicrobial effect of a newly devised toothbrush with light-emitting diodes (LEDs) on Porphyromonas gingivalis attached to sandblasted and acid-etched titanium surfaces. METHODS: The study included a control group, a commercial photodynamic therapy (PDT) group, and 3 test groups (B, BL, and BLE). The disks in the PDT group were placed in methylene blue and then irradiated with a diode laser. The B disks were only brushed, the BL disks were brushed with an LED toothbrush, and the BLE disks were placed into erythrosine and then brushed with an LED toothbrush. After the different treatments, bacteria were detached from the disks and spread on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy was performed to visualize bacterial alterations. RESULTS: The number of viable bacteria in the BLE group was significantly lower than that in the other groups (P < 0.05). Scanning electron microscopy showed that bacterial cell walls were intact in the control and B groups, but changed after commercial PDT and LED exposure. CONCLUSIONS: The findings suggest that an LED toothbrush with erythrosine treatment was more effective than a commercial PDT kit in reducing the number of P. gingivalis cells attached to surface-modified titanium in vitro.

Antimicrobial Effect on Streptococcus mutans in Photodynamic Therapy using Different Light Source / 대한소아치과학회지

In a photodynamic therapy, the difference of antibacterial capacity was compared according to the type of source of light when the same quantity of energy is irradiated.After S. mutans is formed in planktonic state and biofilm state, erythrosine diluted to 40 µM was treated for 3 minutes, and as the type of light source, Halogen, LED, and Plasma arc were used, which were irradiated for 30 seconds, 15 seconds and 9.5 seconds, respectively.After the completion of the experiment, CFU of each experiment arm was measured to compare the photodynamic therapeutic effects according to each condition.The CFU of each experiment arm had no statistically significant difference.Under the same quantity of energy, the photodynamic therapeutic effect can be said to be the same regardless of types of light source, which is a useful result in the clinical field with various light irradiators.

Postantibiotic Effects of Photodynamic Therapy Using Erythrosine and Light Emitting Diode on Streptococcus mutans

Dental caries, the most common oral disease, is a multifactorial disease caused by interactions among bacteria within the dental plaque, food, and saliva, resulting in tooth destruction. Streptococcus mutans has been strongly implicated as the causative organism in dental caries and is frequently isolated from human dental plaque. Photodynamic therapy (PDT) is a technique that involves the activation of photosensitizer by light in the presence of tissue oxygen, resulting in the production of reactive radicals capable of inducing cell death. Postantibiotic effect (PAE) is defined as the duration of suppressed bacterial growth following brief exposure to an antibiotic. In this study, the in vitro PAE of PDT using erythrosine and light emitting diode on S. mutans ATCC 25175 was investigated. The PAE of PDT for 1 s irradiation and 3 s irradiation were 1.65 h and 2.1 h, respectively. The present study thus confirmed PAE of PDT using erythrosine on S. mutans.

The effect of photodynamic therapy on Aggregatibacter actinomycetemcomitans attached to surface-modified titanium

PURPOSE: The purpose of this study was to evaluate the effect of photodynamic therapy (PDT) using erythrosine and a green light emitting diode (LED) light source on biofilms of Aggregatibacter actinomycetemcomitans attached to resorbable blasted media (RBM) and sandblasted, large-grit, acid-etched (SLA) titanium surfaces in vitro. METHODS: RBM and SLA disks were subdivided into four groups, including one control group and three test groups (referred to as E0, E30, E60), in order to evaluate the effect of PDT on each surface. The E0 group was put into 500 microL of 20 microM erythrosine for 60 seconds without irradiation, the E30 group was put into erythrosine for 60 seconds and was then irradiated with a LED for 30 seconds, and the E60 group was put into erythrosine for 60 seconds and then irradiated with a LED for 60 seconds. After PDT, sonication was performed in order to detach the bacteria, the plates were incubated under anaerobic conditions on brucella blood agar plates for 72 hours at 37degrees C, and the number of colony-forming units (CFUs) was determined. RESULTS: Significant differences were found between the control group and the E30 and E60 groups (P<0.05). A significantly lower quantity of CFU/mL was found in the E30 and E60 groups on both titanium disk surfaces. In confocal scanning laser microscopy images, increased bacterial death was observed when disks were irradiated for a longer period of time. CONCLUSIONS: These findings suggest that PDT using erythrosine and a green LED is effective in reducing the viability of A. actinomycetemcomitans attached to surface-modified titanium in vitro.

Photodynamic bactericidal effect against Enterococcus faecalis by erythrosine concentration and LED irradiation times / 대한구강보건학회지

OBJECTIVES: The purpose of this study was to provide photodynamic bactericidal effect against Enterococcus faecalis by erythrosine concentrations and LED irradiation times. METHODS: Erythrosine was used as a photosensitizer and green LED (3 Watt, 520-530 nm) was used as light source. E. faecalis ATCC 1943 and E. faecalis ATCC 29212 were used in this study. Approximately 10(5) CFU of bacteria were added in wells of a 96-well microtitration plate. For examining the effects of concentrations of erythrosine, 0, 0.625, 1.25, 2.5, 5, and 10 microM of erythrosine were added in wells containing bacteria. The irradiation time with LED was 30 sec. In another set of experiment, the effect of irradiation time for killing of bacteria was investigated by increasing irradiation time from 0 to 30 s with 10 microM of erythrosine final concentration. After irradiation, each sample was serially diluted with PBS and 50 microl of diluents was spread on duplicate blood agar plates. The plates were incubated for 72 h at 37degrees C under aerobic conditions and the number of CFU was determined. The experiments were repeated four times. The results were analyzed using one-way ANOVA, and Tukey's multiple comparison at a significance level of 0.05. RESULTS: When the erythrosine concentrations were more than 2.5 microM, E. faecalis ATCC 29212 was significantly decreased (P<0.05). The more erythrosine concentrations increased, the more E. faecalis ATCC 1943 decreased statistically significantly (P<0.05). In another set of experiment, when LED irradiation time was more than 20 s, E. faecalis ATCC 1943 decreased significantly (P<0.05), and if the irradiation times was more than 5 s, E. faecalis ATCC 29212 decreased significantly (P<0.05). CONCLUSIONS: PDT using erythrosine and green LED was found to be an effective method in killing E. faecalis.

The Effect of Erythrosine-mediated Photodynamic Therapy on Intraorally Formed Biofilm on Titanium Surface

The purpose of this study was to assess the efficacy of photodynamic therapy (PDT) using erythrosine and a halogen light source to treat a biofilm formed on a machined surface titanium disk in vivo. Ten volunteers carried an acrylic appliance containing six machined surface titanium disks on the upper jaw over a period of five days. After the five days of biofilm formation period, the disks were removed. PDT using 20 microM erythrosine and halogen light was then applied to the biofilms formed on the disks. Experimental samples were divided into a negative control group (no erythrosine and no irradiation), E0 group (erythrosine 60s + no irradiation), E30 group (erythrosine 60s + halogen light 30s), and E60 group (erythrosine 60s + halogen light 60s). Following PDT, the bacteria in the biofilm were found to be detached from each disk. Each suspension with detached bacteria were diluted and cultivated on a blood-agar plate for five days under anaerobic conditions. The cultivated bacterial counts in the E60 group were significantly lower than the control group (86.4%) or E0 group (76.7%). In the experimental groups also, the light exposure time and bacterial counts showed a negative correlation. In conclusion, PDT using erythrosine and halogen light has bactericidal effects on biofilms formed on a titanium disk in vivo. Notably, applying 20 microM erythrosine and 60 seconds of halogen light irradiation had a significantly potent effect.

Comparison of photodynamic bactericidal effects of erythrosine against Streptococcus mutans and Streptococcus sobrinus by different wavelength of LED lights / 대한구강보건학회지

No abstract available.

Susceptibility of planktonic cultures of Streptococcus mutans to photodynamic therapy with a light-emitting diode

The objective of this study was to evaluate the effect of photodynamic therapy with erythrosine and rose bengal using a light-emitting diode (LED) on planktonic cultures of S. mutans. Ten S. mutans strains, including nine clinical strains and one reference strain (ATCC 35688), were used. Suspensions containing 10(6) cells/mL were prepared for each strain and were tested under different experimental conditions: a) LED irradiation in the presence of rose bengal as a photosensitizer (RB+L+); b) LED irradiation in the presence of erythrosine as a photosensitizer (E+L+); c) LED irradiation only (P-L+); d) treatment with rose bengal only (RB+L-); e) treatment with erythrosine only (E+L-); and f) no LED irradiation or photosensitizer treatment, which served as a control group (P-L-). After treatment, the strains were seeded onto BHI agar for determination of the number of colony-forming units (CFU/mL). The results were submitted to analysis of variance and the Tukey test (p < 0.05). The number of CFU/mL was significantly lower in the groups submitted to photodynamic therapy (RB+L+ and E+L+) compared to control (P-L-), with a reduction of 6.86 log10 in the RB+L+ group and of 5.16 log10 in the E+L+ group. Photodynamic therapy with rose bengal and erythrosine exerted an antimicrobial effect on all S. mutans strains studied.

Characterization of erythrosine B binding to bovine serum albumin and bilirubin displacement.

The interaction of erythrosine B (ErB), a commonly used dye for coloring foods and drinks, with bovine serum albumin (BSA) was investigated both in the absence and presence of bilirubin (BR) using absorption and absorption difference spectroscopy. ErB binding to BSA was reflected from a significant red shift of 11 nm in the absorption maximum of ErB (527 nm) with the change in absorbance at λmax. Analysis of absorption difference spectroscopic titration results of BSA with increasing concentrations of ErB using Benesi-Hildebrand equation gave the association constant, K as 6.9 104 M-1. BR displacing action of ErB was revealed by a significant blue shift in the absorption maximum, accompanied by a decrease in absorbance difference at λmax in the difference spectrum of BR-BSA complex upon addition of increasing concentrations of ErB. This was further substantiated by fluorescence spectroscopy, as addition of increasing concentrations of ErB to BR-BSA complex caused a significant decrease in fluorescence at 510 nm. The results suggest that ErB binds to a site in the vicinity of BR binding site on BSA. Therefore, intake of ErB may increase the risk of hyperbilirubinemia in the healthy subjects.

The Effect of Compressed Air Jet Cleaning on the Elimination of Postoperative Residual Protein from a ProSeal(TM) Laryngeal Mask Airway / 대한마취과학회지

BACKGROUND: The reusable ProSeal(TM) laryngeal mask airways (PLMA's) have the potential to act as a vector for the transmission of prion diseases such as variant Creutzveldt-Jacob disease. This study tested the hypothesis that supplementary compressed air jet cleaning facilitates the removal of protein deposits on PLMA's after surgery. METHODS: After clinical use, thirty PLMA's were randomly allocated to be washed by hand and with an autoclave (134 degrees C for 40 min) (group 1, n = 15), or by hand, autoclave and compressed air jet cleaning (1 min) (group 2, n = 15). In both groups, protein deposits were detected on PLMA's by erythrosine staining. A staining score designated as nil, mild, moderate, and severe was given to each site (outer, inner surface and edges of the cuff, airway and drain tube, finger strap) according to the percentage of stained surface area. The severity of staining was compared for masks prior to use and after cleaning the mask. RESULTS: Despite the cleaning of masks, the staining score worsened on the outer, inner surface and edge of PLMA's in both groups (P < 0.05); however, a similar pattern was observed on each part of a cleaned PLMA for both groups. CONCLUSIONS: We conclude that compressed air jet cleaning for 1 min did not improve the removal of protein deposits on PLMA's after surgery.