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The efficacy of Zerumbone (ZER) against mixed biofilms of fluconazole-resistant Candida albicans (ATCC 96901) and Streptococcus mutans (UA159) was evaluated. Biofilms were cultivated on acrylic resin specimens for 48 h, with alternating supplementation of glucose and sucrose. ZER's ability to inhibit biofilm formation (pre-treatment) and eradicate mature biofilms (post-treatment) was assessed. Control groups were treated with Chlorhexidine (CHX), Nystatin (NYS), Penicillin (ATB), and distilled water. The efficacy was measured by colony forming units (CFU/mm 2 ) counts, biomass and biofilm's matrix components quantification (water-soluble polysaccharides [WSP], alkali-soluble polysaccharides [ASPs], proteins, and extracellular DNA [eDNA]). Data were analyzed by one-way ANOVA with Tukey's or Gammes-Howell post-hoc test for normal data and Kruskal-Wallis test for data that did not meet the assumption of normality (α = 0,05). In the biofilm inhibition assay, ZER decreased total microbiota ( C. albicans + S. mutans ) (2.7 log 10 ; p  < 0.005), C. albicans (1.4 log 10 ; p  < 0.038) and S. mutans (1.9 log 10 ; p  < 0.048) counting (vs control group), and biofilm components [insoluble proteins: 37% ( p  < 0.001); WSP: 13% ( p  < 0.042); ASP: 46% ( p  < 0.001); eDNA: 11% ( p  < 0.048)]. Post-treatment with ZER reduced total microbiota (3.2 log 10 ; p  < 0.001), C. albicans (3 log 10 ; p  < 0.001) and S. mutans (2 log 10 ; p  < 0.001) counting (vs control group), and biofilm components [soluble proteins: 20% ( p  < 0.001); WSP: 20% ( p  < 0.001); ASP: 51% ( p  < 0.001); and eDNA: 33% ( p  < 0.001)]. The positive control groups demonstrated similar or lower efficacy than ZER under all experimental conditions. ZER demonstrates efficacy against mixed biofilms by reducing C. albicans and S. mutans counting and disrupting the extracellular matrix in both assays.

Extracts of Cryptocarya species have been shown to reduce biofilms, demonstrating their antimicrobial effects. The extracts can be fractionated to optimize their potential. In this study, we evaluated the antimicrobial activity of Cryptocarya moschata fractions against planktonic cells and biofilms of Candida albicans and Streptococcus mutans . Four fractions were prepared: 100% hexane, acetate/hexane 1:1, 100% ethyl acetate, and water. The effect of the fractions on planktonic cells was assessed by counting the colony-forming units per milliliter (CFU/mL). Biofilm tests included CFU/mL, cell metabolic activity, and qualitative analysis using confocal laser scanning microscopy (CLSM). Results were analyzed by the Mann-Whitney U test (α = 0.05). The fractions contained lipophilic constituents, styrylpyrones, glycosylated flavonoids, and alkaloids. Acetate/hexane (1:1) and 100% ethyl acetate fractions reduced the CFU/mL of planktonic C. albicans. C. moschata fractions did not affect planktonic S. mutans . For biofilms, the fractions reduced the CFU/mL (from 2-5 logs) and cell metabolic activity (approximately 80% reduction in a single-species biofilm). CLSM showed the fractions reduced microorganism viability and damaged the extracellular matrix of biofilms. We conclude that the acetate/hexane 1:1 and 100% ethyl acetate C. moschata fractions exhibit antimicrobial effects against biofilms.

Objective: This study proposed to assess the effect of Cryptocarya moschata extract on single and mixed biofilms formed on denture base and reline acrylic resin., Materials and Methods: Single and mixed biofilms of Candida albicans and Streptococcus mutans were formed on the samples and treated with C. moschata extract; Nystatin solution at 100,000 IU/mL or Penicillin antibiotic solution at 100,000 IU/mL; or PBS solution. Antimicrobial activity was analyzed by counting colony-forming units, metabolism assay, assessment of protein components of the biofilm matrix, and of cell viability using confocal laser scanning microscopy (CLSM). Data were submitted to ANOVA and Tukey's post-test (α = 0.05)., Results: Cryptocarya moschata extract reduced cell viability of C. albicans and S. mutans single and mixed biofilms formed on samples. For all types of biofilms in the C. moschata group, there was a log reduction of the biofilm, proven by the Alamar Blue assay. Analyzing the extracellular matrix protein components, groups treated with the extract exhibited a lower level of fluorescence compared to the PBS groups. Reduction in thickness biofilm and viable cells was perceptible in the C. moschata group when assessing through CLSM., Conclusion: Cryptocarya moschata extract reduced the single and mixed biofilms of C. albicans and S. mutans on acrylic resins., (© 2024 Wiley Periodicals LLC.)

To evaluate the effect of antiseptic soap on single and dual-species biofilms of Candida albicans and Streptococcus mutans on denture base and reline resins. Samples of the resins were distributed into groups (n = 9) according to the prevention or disinfection protocols. In the prevention protocol, samples were immersed in the solutions (Lifebuoy, 0.5% sodium hypochlorite solution and PBS) for 7, 14 and 28 days before the single and dual-species biofilms formation. Overnight denture disinfection was simulated. In the disinfection protocol, samples were immersed in the same solutions during 8 hours after the single and dual-species biofilms formation. Antimicrobial activity was analyzed by counting colony-forming units (CFU/mL) and evaluating cell metabolism. Cell viability and protein components of the biofilm matrix were evaluated using confocal laser scanning microscopy (CLSM). Data were submitted to ANOVA, followed by Tukey's post-test (α = 0.05) or Dunnett's T3 multiple comparisons test. In the prevention protocol, Lifebuoy solution effectively reduced the number of CFU/mL of both species. In addition, the solution decreased the cell metabolism of the microorganisms. Regarding disinfection protocol, the Lifebuoy solution was able of reduce approximately of 2-3 logs for all the biofilms on the denture base and reline resin. Cellular metabolism was also reduced. The images obtained with CLSM corroborate these results. Lifebuoy solution was effective in reducing single and dual-species biofilms on denture base and reline resins., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Tasso et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

This study evaluated the efficacy of Cryptocarya spp extracts on biofilm of Candida albicans and its biocompatibility. Mature biofilm of C. albicans was formed on denture base acrylic resin samples and the fungicidal effect of the extracts was evaluated by Alamar Blue® assay, counting colony-forming units (CFU/mL) and confocal laser scanning microscopy (CLSM). Cytotoxicity of extracts from Cryptocarya species was evaluated by AlamarBlue® assay, using normal oral keratinocytes (NOK) cells. In additional, Analysis of plant extracts by ultra-high-performance liquid chromatography-diode array detector-tandem mass spectrometry (UPLC-DAD-MS) was performed. The results showed significant reduction in the cellular metabolism and in the number of CFU/mL of C. albicans (p<0.05). The concentration of 0.045 g/mL completely inhibited the number of CFU/mL. Regarding cytotoxicity, all extracts decreased cell viability compared to the control group. CLSM analysis showed predominance of live cells, but with a great difference between the groups. Antimicrobial activity of extracts from Cryptocarya on C. albicans biofilm was confirmed. However, all extracts showed toxicity on NOK cells., Competing Interests: The authors have declared that no competing interests exist.

Background: Staphylococcus aureus have a great ability to become rapidly resistant to conventional antimicrobial therapies. This study evaluated the efficacy of antimicrobial photodynamic therapy (aPDT) mediated by Curcumin (Cur) and light-emitting diode (LED) in the inactivation of biofilms of methicillin susceptible and resistant S. aureus (MSSA and MRSA, respectively)., Methods: Biofilms were treated with Cur (20, 40 or 80 μM) and illuminated with LED source (455 ± 3 nm; 5.28 J/cm 2 ) (aPDT groups), or treated either with Cur or LED only. Other samples were not exposed to Cur or LED (negative control). The biofilms viability after all experimental conditions were evaluated by counting the number of colonies (CFU/mL) and XTT assay. Additional samples were also evaluated by LIVE/DEAD® staining using confocal laser scanning microscopy (CLSM). Data were analyzed by ANOVAs followed by the Games-Howell post hoc test (α = 0.05)., Results: For both strains, all aPDT groups significantly reduced both CFU/mL and metabolic activity of biofilms compared to the negative control (p < 0.001). The results were enhanced when 80 μM of Cur was used. CLSM images showed that both bacteria biofilms submitted to aPDT had a large number of red-stained colonies, especially at aPDT80. In general, MRSA biofilms tended to be less susceptible to aPDT than MSSA biofilms., Conclusions: It can be concluded that aPDT mediated by Cur and LED was an efficient method to inactivate 48 -h biofilms of both S. aureus strains., Competing Interests: Declarations of interest All authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: To investigate the influence of surface characteristics and saliva on the adhesion and biofilm formation of Candida glabrata and methicillin-resistant Staphylococcus aureus (MRSA) to soft liners and tissue conditioners., Methods: For each material (Ufi Gel P - UG; Sofreliner S - SS; Trusoft - TR; Coe Comfort - CC; Softone - ST), specimens were prepared and roughness (Ra), hydrophobicity (water contact angles-WCA) and surface free energy (SFE) were measured. Surface morphology was also analyzed using scanning electron microscopy (SEM). Specimens were incubated in C. glabrata or MRSA suspensions for 90 minutes (adhesion) or 48 hours (biofilm). The absorbance (AB) was measured by XTT assay. Experiments were performed using specimens that were either uncoated or had been coated with saliva. Data were analyzed using one- or two-way ANOVAs, followed by Tukey's test (α= 0.05)., Results: TR exhibited the highest Ra and UG the lowest. SEM images also showed that UG and SS had smooth surfaces, while TR presented several irregularities and pores. In the absence of saliva, UG and SS presented higher WCA and lower SFE than the other materials. XTT results showed that, in the C. glabrata adhesion assay, the AB value was higher for TR followed by UG > CC> SS> ST. For the biofilm formation of C. glabrata, AB values were in the following order TR > CC = UG > ST = SS. In the adhesion assay, AB values obtained for MRSA were TR > UG = CC > ST > SS and for the biofilm formation were TR > ST > CC > UG > SS. Saliva decreased the WCA and increased the SFE for all materials. In general, the presence of saliva decreased the adhesion and biofilm formation of both microorganisms to the acrylic-based material (TR) and tissue conditioners (CC and ST), and increased for the silicone-based soft liners (UH and SS). Surface characteristics and the influence of saliva varied among materials. Roughness seemed to favor C. glabrata and MRSA adhesion and biofilm formation., Clinical Significance: The presence of microorganisms on denture liners can irritate the oral tissues and contribute to systemic diseases. Colonization with more tolerant microorganisms such as C. glabrata and MRSA may expose patients to a greater risk of infection, mainly in immunocompromised hosts, such as aged individuals after treatment of oral cancer. For this, it is important to investigate the surface characteristics of soft liners and tissue conditioners, as well as saliva, and their influence on the adhesion and biofilm formation of C. glabrata and methicillin-resistant Staphylococcus aureus., Competing Interests: The authors declared no conflict of interest. The study was supported by the National Council for Scientific and Technological Development (CNPq; grant – 304190/2013-6)., (Copyright©American Journal of Dentistry.)

This study evaluated the effectiveness of antimicrobial photodynamic therapy (aPDT) mediated by Photodithazine ® (PDZ) formulated in hydrogel, in the inactivation of mono and duo-species biofilms of Candida albicans, Candida glabrata and Candida tropicalis. Standardized suspensions of each strain were prepared and after biofilm formation, mono-species were treated with 150 and 175mg/L of PDZ for 20min (pre-irradiation time), and exposed to LED light at a dose of 37.5J/cm 2 (660nm). The duo-species biofilms (C. albicans+C. glabrata and C. albicans+C. tropicalis) were treated with 150mg/L of PDZ and light. Additional samples were treated with PDZ or light only, and the control did not receive any treatment. Next, microbiological evaluation was performed by spreading the cells on Sabouraud Dextrose Agar and CHROMagar Candida for colony forming units (CFU/mL). Moreover, the total biomass of biofilm was verified using the crystal violet staining assay (CV). The data were submitted to ANOVA and Tukey post-hoc (α=0.05). The use of PDZ 150mg/L promoted a reduction of 1.0, 1.2, 1.5 log 10 in the viability of C. glabrata, C. albicans and C. tropicalis, respectively. The same concentration reduced in 1.0 log 10 the viability of each species grown as duo-species biofilms. The crystal violet assay showed that the use of 150mg/L reduced 24.4%, 39.2% and 43.7% of the total biomass of C. albicans, C. tropicalis and C. glabrata, respectively. aPDT did not reduce the total biomass to the duo-species biofilms. Thus, PDZ-mediated aPDT was more effective in the inactivation of mono-species biofilms of Candida spp. compared with duo-species biofilm., (Copyright © 2016 Elsevier B.V. All rights reserved.)

This study evaluated the potential of curcumin-mediated antimicrobial photodynamic inactivation (API) on multispecies biofilms of Candida albicans, Candida glabrata, and Streptococcus mutans of different ages. Acrylic samples (n = 480) were made with standardized rough surfaces and incubated with bacteria and yeast for 24 or 48 h. API was performed with curcumin (80, 100, 120 μM) and LED light. Additional acrylic samples were treated with curcumin or LED light only. Positive control samples received neither light nor curcumin. After API, colony counts were quantified (CFU/mL), cell metabolism was determined by means of XTT assay, and the total biofilm biomass was evaluated using Crystal Violet (CV) staining assay and images were obtained by confocal laser scanning microscopy (CLSM). The data were analyzed by nonparametric two-way ANOVA and post hoc Tukey tests (α < 0.05). For 24-h biofilm, API resulted in statistically significant difference (ρ < 0.001) of viability of C. albicans compared with control (P-L-) for all Cur concentrations. For 48-h biofilm, API resulted in statistically significant difference (ρ < 0.001) compared with control only when Cur at 120 μM was used. API promoted statistically significant difference (ρ ≤ 0.001) in the viability of S. mutans and C. glabrata for all Cur concentrations in the two biofilm ages. In addition, API produced a statistically significant difference (ρ < 0.001) of metabolic activity and of total biomass (ρ < 0.001) of multispecies biofilms compared with control for all Cur concentrations. It can be concluded that both 24- and 48-h biofilms were susceptible to API mediated by Cur; however, 24-h biofilm was more sensitive than the 48-h biofilm.

Purpose: To investigate the efficacy of immersion and brushing with different cleansing agents in reducing the viability of multispecies biofilm on acrylic resins., Methods: Lucitone 550 (L) and Tokuyama Rebase Fast II (T) specimens (10 x 2 mm) were prepared, sterilized, and inoculated with a suspension of Candida albicans, Candida glabrata, and Streptococcus mutans. Specimens were incubated for 48 hours at 37 degrees C for biofilm formation. Then, they were divided into groups (n = 12) and subjected to brushing or immersion for 10 seconds in distilled water (W), 0.2% peracetic acid-Sterilife (Ac), 1% chlorhexidine digluconate (CHX), 1:1 water/dentifrice solution (D), 1% sodiumhypochlorite (NaOCl), and sodium perborate/Corega Tabs (Pb). Viable microorganisms were evaluated by the XTT assay and colony counts (cfu/mL). Data were performed by ANOVA and Tukey test with 5% significance level., Results: The multispecies biofilm on L and T were killed by brushing or immersion in Ac, CHX, and NaOCl for only 10 seconds.

Purpose: To evaluate the effect of disinfection with sodium perborate or chlorhexidine (when combined with brushing) on the removal of biofilm in relined dentures., Methods: Swabs were collected 48 hours after the relining procedure and at the follow-up time intervals of 7, 15, 30, 90, and 180 days. The dentures' surface roughness was measured at the same times. 45 subjects were randomly divided into three groups of 15 subjects each. The control group brushed with coconut soap and a soft toothbrush. The sodium perborate group followed the same procedure and also disinfected with sodium perborate solution for 5 minutes per day. The chlorhexidine group followed the control group procedure and disinfected with 2% chlorhexidine digluconate solution for 5 minutes per day. The number of colony forming units and the surface roughness were evaluated statistically by 2-way repeated-measure ANOVA (α = 0.05)., Results: The control group dentures exhibited similar levels of microbial cells throughout the experiment. However, after 15 days, no microbial growth was observed on the dentures for which either disinfection agent was used. There were no statistically significant differences in superficial roughness between the groups (P = 0.298). The disinfection agents used, combined with brushing, were able to remove the relined dentures' biofilm after 15 days of disinfection. Roughness was not a predominant factor in CFU reduction.

In this investigation, the effectiveness of successive applications of antimicrobial photodynamic inactivation (API) mediated by Photodithazine(®) (PDZ) and LED light was evaluated against a multispecies biofilm formed by Candida albicans, Candida glabrata, and Streptococcus mutans on denture base acrylic resin. Standard cell suspensions (bacteria and yeast) were inoculated on acrylic resin samples, and the biofilm was grown for 48 h (37 °C/75 rpm). API was performed by the administration of PDZ (175 and 200 mg/L) and exposure to 37.5 J/cm(2) of LED light (660 nm). Additional samples were treated with PDZ or LED light only. Untreated control samples were not submitted to light or PDZ. The conditions described were applied once or in three consecutive applications for all groups. Cell viability was determined by colony counts (CFU/mL), metabolic activity, total biomass, and confocal laser scanning microscopy (CLSM). Data were analyzed by a nonparametric two-way ANOVA and Tukey tests (α = 0.05). The results obtained demonstrated a significant effect (p < 0.05) of number of applications and treatment groups for CFU/mL, and S. mutans showed the highest susceptibility to API. The metabolic activity of the multispecies biofilm was significantly reduced (p < 0.05) after API for both numbers of applications, which were also significantly different (p < 0.05) between them. The total biomass of the biofilm was significantly different (p < 0.05) only between groups submitted to one and three API applications. CLSM showed a visual increase of dead cells after API. API-mediated PDZ was effective in reducing the cell viability of multispecies biofilm. Three consecutive applications of API were more effective for reducing the cell viability and the total biomass of multispecies biofilm.

Statement of Problem: Routine cleaning of a denture may increase the surface roughness of the material., Purpose: The purpose of this study was to investigate the effect of denture cleansers and time on the roughness and Candida albicans biofilm formation on a reline resin., Material and Methods: Specimens of Tokuyama Rebase Fast II (20 × 10 × 2 mm) were prepared and divided into 9 groups (n=15): Test groups were toothbrushed (30 cycles per day) in 1 of the following solutions: water, soap, or toothpaste. After toothbrushing, the specimens were immersed in solutions of water, sodium perborate, or chlorhexidine. These treatments were done once a day for 365 days. The surface roughness was evaluated at 0, 7, 15, 30, 90, 180, 270, and 365 days, and the C albicans biofilm formation was measured after 365 days. The roughness data were analyzed by 3-way repeated measures ANOVA and the Tukey test (α=.05), and the C albicans biofilm formation was analyzed by 2-way ANOVA., Results: Significant differences were found in the toothbrush and time interaction and in the toothbrush, immersion, and time interaction (P<.001). No significant differences were found between the toothbrush agent and chemical disinfection (P=.085) or between chemical disinfection and time interaction (P=.604). Brushing with dentifrice (PPb and PCh) showed a gradual decrease in surface roughness. The comparison among groups showed that PCh produced the lowest values of roughness. For C albicans biofilm formation, no significant differences were found among the experimental groups., Conclusions: The roughness values ranged from 0.31 to 0.69 μm for all evaluated groups. For all groups, no significant differences were found in the quantification of C albicans., (Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Methicillin-resistant Staphylococcus aureus (MRSA) can grow as structured biofilm in different surfaces, including oral mucosa and denture surfaces. Such biofilms can be released into the oral fluids and aspirated, causing systemic infections such as aspiration pneumonia. This study evaluated the efficacy of two disinfectant solutions and microwave irradiation in disinfecting acrylic specimens contaminated with MRSA biofilm. Thirty-six acrylic specimens were made, sterilized and contaminated with MRSA (107 cfu/mL). After incubation (37 °C/48 h), the specimens were divided into 4 groups: not disinfected (positive control); soaking in 1% sodium hypochlorite for 10 min; soaking in 2% chlorhexidine gluconate for 10 min; and irradiating by microwave for 3 min at 650 W. The viability of cells was evaluated by XTT reduction method. All specimens from the positive control group showed biofilm formation after 48 h incubation. The mean absorbance value of the control specimens was 1.58 (OD at 492 nm). No evidence of biofilm formation was observed on specimens after the disinfection methods. Disinfection by soaking in 1% sodium hypochlorite and 2% chlorhexidine gluconate and irradiating by microwaves resulted in 100% reduction of MRSA biofilm metabolism. The use of chemical solutions and microwave irradiation was shown to be effective for eradicating mature MRSA biofilms on acrylic resin specimens.

New drug delivery systems, such as nanoemulsions (NE), have been developed to allow the use of hydrophobic drugs on the antimicrobial photodynamic therapy. This study evaluated the photodynamic potential of aluminum-chloride-phthalocyanine (ClAlPc) entrapped in cationic and anionic NE to inactivate Candida albicans planktonic cultures and biofilm compared with free ClAlPc. Fungal suspensions were treated with different delivery systems containing ClAlPc and light emitting diode. For planktonic suspensions, colonies were counted and cell metabolism was evaluated by XTT assay. Flow cytometry evaluated cell membrane damage. For biofilms, the metabolic activity was evaluated by XTT and ClAlPc distribution through biofilms was analyzed by confocal laser scanning microscopy (CLSM). Fungal viability was dependent on the delivery system, superficial charge and light dose. Free ClAlPc caused photokilling of the yeast when combined with 100 J cm(-2). Cationic NE-ClAlPc reduced significantly both colony counts and cell metabolism (P < 0.05). In addition, cationic NE-ClAlPc and free ClAlPc caused significant damage to the cell membrane (P < 0.05). For the biofilms, cationic NE-ClAlPc reduced cell metabolism by 70%. Anionic NE-ClAlPc did not present antifungal activity. CLSM showed different accumulation on biofilms between the delivery systems. Although NE system showed a lower activity for planktonic culture, cationic NE-ClAlPc showed better results for Candida biofilms., (© 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.)