Viability Of Candida Albicans Research Articles

Green Synthesis of Silver Nanoparticles using Moringa oleifera: Implementation to Photoantimicrobial of Candida albicans with LED Light

Green synthesis of silver nanoparticles using Moringa oleifera (AgNPs/MO) was carried out to produce nanoscale antifungal agents which are used as photosensitizing agents in photoantimicrobial therapy. This study focused on investigating the potential of AgNPs/MO producing some toxic radical compounds that inhibit the growth of Candida albicans biofilms. The inhibition mechanism uses the principle of photoinactivation treatment which combines a photosensitizer with an LED light source at a power of 100 mW for 60 - 300 s of exposure. Quantitative data analyzed were the number of viable cells and radical compounds, formed by malondialdehyde (MDA) level. It is investigated through staining the XTT (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) and TBARS (Thiobarbituric Acid Reactive Substances). The results show that the maximum wavelength of AgNPs is 440 nm while the Moringa oleifera has 2 peaks at 425 and 635 nm. The maximum effect occurred in the group of photosensitizer AgNPs/MO combined LED with percentage inactivation about 76.80 % for blue LEDs and 76.20 % for red LEDs. The group of LED irradiation without photosensitizer obtained about 51.85 % for blue LEDs and 50.04 % for red LEDs. The MDA level group of AgNPs/MO combined LED also produced MDA levels of 1.772 nmol/mL for blue LED and 1.617 nmol/mL for red LED. Meanwhile, the application of photoantimicrobial using only LEDs produced MDA levels of only 1.353 nmol/mL for blue LEDs and 1.347 nmol/mL for red LEDs. This research has shown that the green synthesis of AgNPs/MO has a good potential to inhibit the growth of Candida albicans biofilms as a photosensitizer agent. HIGHLIGHTS Silver nanoparticles (AgNPs) combined with Moringa oleifera (MO) extract have been shown to have potential as a photosensitizer to inhibit the growth of Candida albicans Green synthesis AgNPs/MO have a characteristic spectrum at 440 nm which is close to the blue light spectrum. Green synthesis AgNPs/MO combined with LED light irradiation energy can reduce the cell viability of Candida albicans up to 76.80 % through the XTT assay staining test method and produce 1.772 nmol/mL of Malondialdehyde that reacts with ROS compounds to cause cell damage. GRAPHICAL ABSTRACT

Titanium coated with 2-decenoic analogs reduces bacterial and fungal biofilms.

Due to antibiotic tolerance of microbes within a biofilm, non-antibiotic methods for prevention and treatment of implant-related infections are preferable. The goal of this work is to evaluate a facile loading strategy for short-chain fatty-acid signaling molecules 2-heptycyclopropane-1-carboxylic acid (2CP), cis-2-decenoic acid (C2DA), and trans-2-decenoic acid (T2DA), which all act as diffusible signaling factors (DSFs), onto titanium surfaces for comparison of their antimicrobial efficacy. Titanium coupons were drop coated with 0.75mg of DSF in ethanol and dried. Surface characteristics and presence of DSF were confirmed with Fourier Transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS), and water contact angle. Antimicrobial assays on 12-well plates analyzing biofilm and planktonic Staphylococcus aureus, Escherichia coli, or Candida albicans viability showed that planktonic growth was reduced after 24-hour incubation, but only sustained through 72 hours for S. aureus and C. albicans. Biofilm formation on the titanium coupons was also reduced for all strains at the 24-hour time point, but not through 72 hours for E. coli. Although approximately 60% of the loaded DSF was released within the first 2 days, enough remained on the surface after 4 days of elution to significantly inhibit E. coli and C. albicans biofilm. Cytocompatibility evaluations with a fibroblast cell line showed that none of the DSF loaded groups decreased viability, while C2DA and 2CP increased viability by up to 50%. In this study we found that DSF-loaded titanium coupons can inhibit planktonic microbes and prevent biofilm attachment, without toxicity to mammalian cells.

Structural analysis of the Candida albicans mitochondrial DNA maintenance factor Gcf1p reveals a dynamic DNA-bridging mechanism.

The compaction of mitochondrial DNA (mtDNA) is regulated by architectural HMG-box proteins whose limited cross-species similarity suggests diverse underlying mechanisms. Viability of Candida albicans, a human antibiotic-resistant mucosal pathogen, is compromised by altering mtDNA regulators. Among them, there is the mtDNA maintenance factor Gcf1p, which differs in sequence and structure from its human and Saccharomyces cerevisiae counterparts, TFAM and Abf2p. Our crystallographic, biophysical, biochemical and computational analysis showed that Gcf1p forms dynamic protein/DNA multimers by a combined action of an N-terminal unstructured tail and a long helix. Furthermore, an HMG-box domain canonically binds the minor groove and dramatically bends the DNA while, unprecedentedly, a second HMG-box binds the major groove without imposing distortions. This architectural protein thus uses its multiple domains to bridge co-aligned DNA segments without altering the DNA topology, revealing a new mechanism of mtDNA condensation.

Effect of alkynyloxy derivatives of lawsone as an antifungal spray for acrylic denture base: An in vitro study

ObjectiveThe purpose of this study was to (i) synthesize and develop an alkynyloxy derivative of lawsone as an antifungal spray and (ii) assess the antifungal spray’s effectiveness in reducing the viability of Candida albicans (C. albicans) on polymethylmethacrylate (PMMA) specimens. MethodsLawsone methyl ether (LME) and its derivative, 2-(prop-2-ynyloxy)naphthalene-1,4-dione (compound 1) were synthesized and characterized. The synthetic compounds were screened for antimicrobial activities against C. albicans using the microtiter broth dilution method to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). Compound 1 was further formulated as an antifungal spray in three concentrations (100, 200, and 400 μg/mL). C. albicans biofilms were developed for 48 h on PMMA specimens. The efficacy of using an antifungal spray for 1 and 3 min to remove biofilm was assessed using colony counting and scanning electron microscopy (SEM). Chlorhexidine gluconate (CHX), polident®, and distilled water were used as positive and negative control cleansing solutions, respectively. ResultsLME and compound 1 showed comparable inhibition against C. albicans with a MIC of 25 μg/mL and MFC of 50 μg/mL. For immediate treatment, C. albicans was not detected on PMMA specimens when expose to 2% CHX and compound 1 (100, 200, and 400 μg/mL) antifungal spray for 3 min. However, after recolonization, a small number of viable cells were observed in denture soaked in compound 1 antifungal spray for 3 min group. Following recolonization, polident® and distilled water had comparable viable cell counts of C. albicans to the no treatment group. Scanning electron microscope (SEM) images revealed that CHX, polident®, and compound 1 caused cell damage in various forms. ConclusionDenture spray containing synthetic alkynyloxy derivative of lawsone is a promising antifungal agent for C. albicans biofilm removal from the PMMA surface.

Integrated omics approach to unveil antifungal bacterial polyynes as acetyl-CoA acetyltransferase inhibitors

Bacterial polyynes are highly active natural products with a broad spectrum of antimicrobial activities. However, their detailed mechanism of action remains unclear. By integrating comparative genomics, transcriptomics, functional genetics, and metabolomics analysis, we identified a unique polyyne resistance gene, masL (encoding acetyl-CoA acetyltransferase), in the biosynthesis gene cluster of antifungal polyynes (massilin A 1, massilin B 2, collimonin C 3, and collimonin D 4) of Massilia sp. YMA4. Crystallographic analysis indicated that bacterial polyynes serve as covalent inhibitors of acetyl-CoA acetyltransferase. Moreover, we confirmed that the bacterial polyynes disrupted cell membrane integrity and inhibited the cell viability of Candida albicans by targeting ERG10, the homolog of MasL. Thus, this study demonstrated that acetyl-CoA acetyltransferase is a potential target for developing antifungal agents.

Plasma Membrane Phosphatidylinositol-4-Phosphate Is Not Necessary for Candida albicans Viability yet Is Key for Cell Wall Integrity and Systemic Infection.

ABSTRACTPhosphatidylinositol phosphates are key phospholipids with a range of regulatory roles, including membrane trafficking and cell polarity. Phosphatidylinositol-4-phosphate [PI(4)P] at the Golgi apparatus is required for the budding-to-filamentous-growth transition in the human-pathogenic fungus Candida albicans; however, the role of plasma membrane PI(4)P is unclear. We have investigated the importance of this phospholipid in C. albicans growth, stress response, and virulence by generating mutant strains with decreased levels of plasma membrane PI(4)P, via deletion of components of the PI-4-kinase complex, i.e., Efr3, Ypp1, and Stt4. The amounts of plasma membrane PI(4)P in the efr3Δ/Δ and ypp1Δ/Δ mutants were ∼60% and ∼40%, respectively, of that in the wild-type strain, whereas it was nearly undetectable in the stt4Δ/Δ mutant. All three mutants had reduced plasma membrane phosphatidylserine (PS). Although these mutants had normal yeast-phase growth, they were defective in filamentous growth, exhibited defects in cell wall integrity, and had an increased exposure of cell wall β(1,3)-glucan, yet they induced a range of hyphal-specific genes. In a mouse model of hematogenously disseminated candidiasis, fungal plasma membrane PI(4)P levels directly correlated with virulence; the efr3Δ/Δ mutant had wild-type virulence, the ypp1Δ/Δ mutant had attenuated virulence, and the stt4Δ/Δ mutant caused no lethality. In the mouse model of oropharyngeal candidiasis, only the ypp1Δ/Δ mutant had reduced virulence, indicating that plasma membrane PI(4)P is less important for proliferation in the oropharynx. Collectively, these results demonstrate that plasma membrane PI(4)P levels play a central role in filamentation, cell wall integrity, and virulence in C. albicans.

Photodynamic potential of curcumin in bioadhesive formulations: Optical characteristics and antimicrobial effect against biofilms

Background: Although Curcumin (CUR) has great potential as a photosensitizer, the low solubility in water impairs its clinical performance in photodynamic inactivation (PDI). This study sought to establish an effective antimicrobial protocol for PDI using CUR in three different bioadhesive formulations. Methods: A CUR-loaded chitosan hydrogel with a poloxamer (CUR-CHIH), a CUR-loaded liquid crystal precursor system (CUR-LCP), a CUR-loaded microemulsion (CUR-ME), and CUR in dimethylsulfoxide (DMSO) solution (CUR-S; control formulation) were tested against in vitro and in situ oral biofilms. The optical properties of each formulation were evaluated. Results: All of the formulations exhibited lower absorbance than CUR-S; however, the CUR-LCP curve bore the highest resemblance. The CUR present in all formulations was completely degraded after 15 min of illumination. In vitro experiments showed that CUR-S was the only formulation able to significantly reduce biofilm viability of Candida albicans and Lactobacillus casei when compared to the negative control (no PDI); the amount of reduction obtained was 1.8 and 3.7 log (CFU/mL) for C. albicans and L. casei, respectively. There was a significant reduction on the viability of Streptococcus mutans biofilms when CUR-S and CUR-LCP were applied (approximately 3.5 and 1.6 log [CFU/mL], respectively). In situ testing showed antimicrobial efficacy against S. mutans and general microorganisms. Conclusions: Although the evaluated protocols has not been effective to all of the evaluated microorganisms, PDI showed potential against dental biofilms and evidence that the phototoxic effects of CUR have a high relation with the type of formulation in which it is loaded.

Viability of Candida albicans in different fomites and hospital surfaces under disinfectants and biological fluids influence

Hospital environment has factors that promote increased infections caused by microorganisms allowing them to remain viable for long periods on surfaces and fomites. The aim of our study was to identify the viability of Candida albicans in hospital environment common surfaces with biological fluids presence and disinfectants. Four surfaces (cotton fabric, synthetic fabric, egg crate foam mattress and, ceramic floor) were contaminated with a strain of Candida albicans ATCC 26790 and with an association of distilled water, blood, saliva and urine. Also, combinations of surfaces and fluids with addition of 70% alcohol and 2% sodium hypochlorite were tested. Viability was identified at 1, 3, 7, 14 and 21 days by Colony Forming Units counting. C. albicans presented 14 days viability in hospitals fabrics with absence of liquids and maintained this persistence under influence of distilled water and blood. It also showed low growth with urine addition and there was growth inhibition with 2% sodium hypochlorite while with 70% alcohol and blood there was persistence for up to 7 days in synthetic fabric and mattress. The understanding of these yeasts persistence in hospital surfaces and fomites is essential for a better delineation of protocols control the spread and these infections prevention in healthcare environments.

The Effect of Various Concentrations of Liquid Smoke with Time Differences on the Viability of Candida albicans

Background: Dentures that are rarely cleaned will trigger the growth of Candida albicans, which is a fungus known to be a major cause of opportunistic infections of the oral cavity. Liquid smoke is a chemical produced by distillation of smoke from combustion, containing phenol, carbonyl and carboxylic acids that are effective in killing fungi.Objective: To determine the effect of various concentrations of liquid smoke with different periods of time on the viability of Candida albicans.Methods: This was an experimental laboratory research with post-test only control group design. This study used Candida albicans colonies as samples with 6 different treatment concentrations of liquid smoke (100%, 50%, 25%, 12.5%, and 6.25%) and different periods of time (5 and 15 minutes), with 5 duplications.Results: The Kruskal-Wallis test on the MIC (Minimum Inhibitory Concentration) showed that there are significant differences (p <0.001) in the experimental groups, while the test on the MBC (Minimum Bactericidal Concentration) also showed the same result (p <0.001). The Mann-Whitney test stated that there was a significant difference between liquid smoke concentrations of 12.5% with positive control. The lowest concentration that could inhibit the growth of Candida albicans is 12.5%. At 24 hours incubation with 5 and 15 minute soaking time, the MBC of Candida albicans was 100% with 15 minute soaking time.Conclusions: Liquid smoke affected the growth of Candida albicans, characterized by MIC at a concentration of 12.5% and MBC at a concentration of 100% with a 15-minute soaking time.

Statherin-derived peptides as antifungal strategy against Candida albicans

ObjectiveThe aim of this in vitro study was to evaluate the effect of statherin and its naturally occurring peptides (DR9-2, DR9, GE-12, IT-32, GQ-19, IP-18) on Candida albicans metabolism and biofilm development. DesignAfter the killing assay, a peptide pellicle was formed on the bottom of a polystyrene plate at the IC50 of each peptide. Over the peptide pellicle, Candida albicans biofilm (48 h) was grown. The peptides antimicrobial activity after the peptides treatment was evaluated by alamarBlue, total biofilm biomass and colony forming units (CFU) counting. ResultsThe pellicle with statherin and the peptides (DR9-2, DR9, GE-12, IP-18, GQ-19) was able to reduce he viability of Candida albicans compared to the negative control. They also decreased cell proliferation by 20 % and total biomass. IT-32 showed the highest reduction in cell proliferation and biomass, which was similar to the positive control, histatin 5. ConclusionsThese results suggest that the naturally occuring peptides from statherin are able to decrease Candida albicans colonization and biofilm proliferation.

Effect of Ultraviolet Radiation on Candida albicans Biofilm on Poly(methylmethacrylate) Resin.

To investigate the effect of 254-nm ultraviolet light on the viability of Candida albicans biofilm on poly(methylmethacrylate). Poly(methylmethacrylate) specimens (1 cm × 1 cm × 1 mm) were placed in 6-well culture plates. Each well contained 8 ml of 104 colony forming units/milliliter of C. albicans ATCC90028 and Sabouraud dextrose broth. Plates were incubated at 37°C for 24 hours. Specimens were then divided into 11 groups (n = 4): no treatment control groups, 3.8% sodium perborate immersion for 5 minutes (PP5m) and for 12 hours (PO12h), and 6 groups exposed to ultraviolet light for 5, 15, 30, 60, 120 or 300 seconds separately using UVP XX-15S series lamps. After sonication, cell suspensions were plated, and colony-forming units were counted. The relationship between survival of C. albicans and ultraviolet light irradiation energy exposure was analyzed and compared to the survival of sodium perborate groups. The effect of disinfection treatments and ultraviolet light energy exposure on C. albicans survival was analyzed with ANOVA (alpha = 0.05). There was a significant decrease in C. albicans survival with increasing ultraviolet light energy exposure (p = 0.00001, p < 0.05) Survival vs. immersion exposure time analysis of chemical disinfection showed no survival of C. albicans in groups PP5m and PO12h. C. albicans in the UV 300s group with energy of 210 mJ/cm2 (71 CFU/ml) showed a statistical difference from that of two chemical immersion groups (PP5m, PO12h = 0 CFU/ml) (p = 0.00001, p < 0.05). Ultraviolet 254 nm irradiation demonstrated a significant inhibition of C. albicans survival on poly(methylmethacrylate) samples. Ultraviolet light exposure of 300 seconds inhibited the survival of C. albicans close to the level of 3.8% sodium perborate treatment.

Novel Bi-Factorial Strategy against Candida albicans Viability Using Carnosic Acid and Propolis: Synergistic Antifungal Action.

The potential fungicidal action of the natural extracts, carnosic acid (obtained from rosemary) and propolis (from honeybees’ panels) against the highly prevalent yeast Candida albicans, used herein as an archetype of pathogenic fungi, was tested. The separate addition of carnosic acid and propolis on exponential cultures of the standard SC5314 C. albicans strain caused a moderate degree of cell death at relatively high concentrations. However, the combination of both extracts, especially in a 1:4 ratio, induced a potent synergistic pattern, leading to a drastic reduction in cell survival even at much lower concentrations. The result of a mathematical analysis by isobologram was consistent with synergistic action of the combined extracts rather than a merely additive effect. In turn, the capacity of SC5314 cells to form in vitro biofilms was also impaired by the simultaneous presence of both agents, supporting the potential application of carnosic acid and propolis mixtures in the prevention and treatment of clinical infections as an alternative to antibiotics and other antifungal agents endowed with reduced toxic side effects.

Evaluation of anti-candida activity of metabolites of enterococcal clinical isolates.

When studying the effect of the metabolic products of clinical isolates of enterococci on the viability of Candida albicans, it was found that metabolites of all tested strains of Enterococcus faecium, E. faecalis had a fungistatic effect. At the same time a reliable fungicidal effect is a strain-specific feature. It is better to use the method of delayed antagonism on double-layer agar to assess the antifungal effect of enterococcal metabolism products.

Viability of Candida albicans in Denture Base Resin After Disinfection: A Preliminary Study.

To quantify the depth of penetration of Candida albicans (C albicans) into a denture base resin and to investigate its viability after disinfection. Heat-polymerizing polymethyl methacrylate plates were contaminated with C albicans, then washed, dried, and prepared for scanning electron microscopy (SEM). Vertical surfaces were cut, and the depth of any penetration was measured. For viability after disinfection, plates were contaminated, subjected to one of two disinfection techniques, and subcultures were taken to determine viability. The results showed that at 7, 14, and 21 days after exposure, the mean depth of penetration of C albicans was 33.9, 96.9, and 97.0 μm, respectively. The depth of penetration was time dependent, with the deepest being 631 μm at 21 days. Daily subcultures for 10 days revealed that penetrated cells remained viable and were not affected by the disinfectant. To the present authors' knowledge, this is the first time that the viability of denture base-penetrated C albicans has been shown, even after disinfection. The implication of these results is that denture resin is likely to be penetrated, especially in patients with chronic or recurrent denture stomatitis. If the C albicans remain viable, then the infected denture-fitting surfaces may have to be replaced by removing at least a 1-mm layer of contaminated resin.

β-lapachone and α-nor-lapachone modulate Candida albicans viability and virulence factors

BackgroundCandida albicans is the most important fungal pathogen that causes infections in humans, and the search for new therapeutic strategies for its treatment is essential. ObjectiveThe aim of this study was to evaluate the activity of seven naphthoquinones (β-lapachone, β-nor-lapachone, bromide-β-lapachone, hydroxy-β-lapachone, α-lapachone, α-nor-lapachone and α-xyloidone) on the growth of a fluconazole-resistant C. albicans oral clinical isolate and the effects of these compounds on the viability of mammalian cells, on yeast's morphogenesis, biofilm formation and cell wall mannoproteins availability. ResultsAll the compounds were able to completely inhibit the yeast growth. β-lapachone and α-nor-lapachone were the less cytotoxic compounds against L929 and RAW 264.7 cells. At IC50, β-lapachone inhibited morphogenesis in 92%, while the treatment of yeast cells with α-nor-lapachone decreased yeast-to-hyphae transition in 42%. At 50μg/ml, β-lapachone inhibited biofilm formation by 84%, whereas α-nor-lapachone reduced biofilm formation by 64%. The treatment of yeast cells with β-lapachone decreased cell wall mannoproteins availability in 28.5%, while α-nor-lapachone was not able to interfere on this virulence factor. Taken together, data show that β-lapachone and α-nor-lapachone exhibited in vitro cytotoxicity against a fluconazole-resistant C. albicans strain, thus demonstrating to be promising candidates to be used in the treatment of infections caused by this fungus.

Effect of copper content on the corrosion behaviors and antibacterial properties of binary Mg–Cu alloys

Biodegradable Mg–Cu alloys have attracted many researchers attention due to their characteristics of osteogenesis, angiogenesis, and long-lasting antibacterial effects. In this paper, the effect of copper content on the corrosion behaviors and antibacterial properties of binary Mg–Cu alloys was studied. Microstructure characterization, immersion test, electrochemical test and antibacterial test were carried out. The results show that with the increase of Cu content, the corrosion rate of Mg–Cu alloys was increased greatly due to the galvanic corrosion between Mg matrix and Mg2Cu intermetallic phase. The corrosion rate of Mg–0·3Cu alloy was almost 10 times as fast as Mg–0·1Cu alloy in 0·9 wt-% NaCl solution. Antibacterial test showed that Mg–Cu alloys could efficiently reduce the viability of Candida albicans with the addition of Cu above 0·1 wt-%. Mg–0·1Cu has good potential to be used as antibacterial implants due to its good corrosion resistance and antibacterial property.

Inhibition of Candida albicans biofilm by pure selenium nanoparticles synthesized by pulsed laser ablation in liquids

Selenoproteins play an important role in the human body by accomplishing essential biological functions like oxido-reductions, antioxidant defense, thyroid hormone metabolism and immune response; therefore, the possibility to synthesize selenium nanoparticles free of any contaminants is exciting for future nano-medical applications. This paper reports the first synthesis of selenium nanoparticles by femtosecond pulsed laser ablation in de-ionized water. Those pure nanoparticles have been successfully used to inhibit the formation of Candida albicans biofilms. Advanced electron microscopy images showed that selenium nanoparticles easily adhere on the biofilm, then penetrate into the pathogen, and consequently damage the cell structure by substituting with sulfur. 50% inhibition of Candida albicans biofilm was obtained at only 25 ppm. Finally, the two physical parameters proved to affect strongly the viability of Candida albicans are the crystallinity and particle size.

Evaluation of the in vitro antimicrobial properties of ultraviolet A/riboflavin mediated crosslinking on Candida albicans and Fusarium solani.

To evaluate the antimicrobial properties of ultraviolet A (UVA) (365 nm)/riboflavin against Candida albicans and Fusarium solani. Two fungus isolates were cultured in vitro and prepared with 10-fold serial PBS dilutions of cell concentration. For each dilution of fungus suspension, the concentration (colony-forming units/mL, CFU/mL) and the inactivation ratio of fungal cells were evaluated under 4 conditions: no treatment (control), UVA (365 nm)/riboflavin, riboflavin, and UVA (365 nm). The cell concentration decreased in UVA (365 nm)/riboflavin group for Candida albicans at each dilution and Fusarium solani at dilutions of 10(4), 10(3), 10(2) CFU/mL, when compared with that in control, riboflavin, and UVA (365 nm) groups (P<0.01). No difference of cell concentration was detected amongst the culture of control, riboflavin, and UVA (365 nm) groups for the two fungus. There is a negative correlation between suspension concentration (log-transformed) and the inactivation ratio in UVA (365 nm)/riboflavin group for Candida albicans and Fusarium solani (P<0.01). According to the standard protocol of corneal collagen cross-linking, UVA (365 nm)/riboflavin combination treatment is found to moderately inactivate the viability of Candida albicans and Fusarium solani in vitro. The inactivation ratio was found to increase with the decrease of cell concentration under UVA (365 nm)/riboflavin condition.

Cell viability of Candida albicans against the antifungal activity of thymol.

Candida albicans is a commensal fungus, but circumstantially it may cause superficial infections of the mucous membranes, such as denture stomatitis, when a biofilm is formed on the surface of dental prostheses. This study evaluated the cell viability of C. albicans biofilms against the antifungal activity of thymol when compared with miconazole, by the fluorescence imaging using SYTO 9 and propidium iodide dyes, and counting of colony forming units. C. albicans standard strains (ATCC 11006) were used. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of drugs were determined by broth microdilution tests and the inoculum was standardized to match 0.5 on the McFarland scale (106 cfu/mL). Biofilms were grown on the surface of acrylic resin disks in parallel flow chambers from Sabouraud broth supplemented with 10% dextrose. For counting of colony forming units, the fungal solution was sequentially diluted and plated in Sabouraud dextrose agar. Data were analyzed using two-way ANOVA and Tukey's test (a=5%). Biofilms treated with thymol and miconazole presented low numbers of viable cells at the evaluated exposure times. There was statistically significant difference (p<0.05) when compared with control, and the mean value of the exposure times between miconazole and thymol did not differ significantly (p>0.05). In conclusion, both drugs have similar efficiency as antifungal agents against biofilms of C. albicans formed on acrylic surfaces.

Fungicidal response of a novel natural photosensitizer (Beta vulgaris) on Candida albicans with low-power laser radiation

We report the efficacy of an aqueous extract of Beta vulgaris as a novel, natural photosensitizer for use in photodynamic therapy against Candidiasis disease. This study evaluates the effect of different laser wavelengths (He–Ne: 633 nm, Nd-YAG: 532 nm), power (17, 27 mW) and duration of exposure (5, 10, 15 min) in combination with the Beta vulgaris natural photosensitizer on the viability of Candida albicans causing Candidiasis disease. Although inhibition was observed in all cases, a maximum of 51.91% inhibition takes place with the combination of Beta vulgaris exposed to 532 nm at 27 mW for 15 min by the Agar well diffusion method. The study is important in optimizing different parameters and designing a low-power, compact, non-invasive and portable device for treatment.