Albicans Adhesion Research Articles

Los glicosaminoglicanos se encuentran implicados en la adherencia de Candida albicans y Malassezia spp. a queratinocitos, pero no a fibroblastos dérmicos

Background and objectiveSuperficial mycoses are some of the most common diseases worldwide. The usual culprits — yeasts belonging to the genera Malassezia and Candida — are commensal species in the skin that can cause opportunistic infections. We aimed to determine whether these yeasts use glycosaminoglycans (GAGs) as adhesion receptors to mediate binding to epithelial cells. Material and methodsIn keratinocyte and dermal fibroblast cultures, we used rhodamine B and genistein to inhibit GAG synthesis to study the role these molecules play in the adhesion of Candida albicans (C. albicans) and Malassezia species to cells. We also analyzed GAG involvement by means of enzyme digestion, using specific lyases. ResultsRhodamine B partially inhibited the adhesion of both fungi to keratinocytes but not to fibroblasts. Selective digestion of heparan sulfate enhanced the binding of Malassezia species to keratinocytes and of both fungi to fibroblasts. Chondroitin sulfate digestion decreased C. albicans adhesion to keratinocytes, but increased the adhesion of the filamentous forms of this species to fibroblasts. ConclusionsCell surface GAGs appear to play a role in the adhesion of C albicans and Malasezzia species to keratinocytes. In contrast, their adhesion to fibroblasts appears to be enhanced by GAG inhibition, suggesting that some other type of receptor is the mediator.

Effect of Denture Base Fabrication Technique on Candida albicans Adhesion In Vitro.

Denture stomatitis is a common manifestation of oral candidiasis affecting some 65% of denture wearers. This condition is initiated by the adherence of Candida albicans to denture base acrylic resin. The present study aimed to test the in vitro effect of traditional and novel fabrication methods on Candida albicans adhesion to denture base samples. Denture based acrylic discs were fabricated using: (i) computerized milling, (ii) 3D printing, (iii) heat curing, and (iv) cold curing. Discs were tested for surface roughness (Ra), hydrophobicity (contact angle), mucin adsorption (Bradford assay), and Candida albicans adhesion. 3D printing significantly increased microbial cell adhesion as compared with heat curing, and computerized milling significantly decreased it. These results were associated with mucin adsorption levels rather than surface roughness. Results suggest that 3D printing may increase the risk for developing denture stomatitis, whereas computerized milling may decrease it as compared with traditional heat curing denture base fabrication.

Interaction of Styrylpyridinium Compound with Pathogenic Candida albicans Yeasts and Human Embryonic Kidney HEK-293 Cells.

Candida albicans-caused local and systemic diseases are a serious health issue worldwide, leading to high mycosis-associated morbidity and mortality. Efficient combinations of novel compounds with commonly used antifungals could be an important tool for fighting infections. The aim of this study was to evaluate the interaction of synthesized 4-(4-cyanostyryl)-1-dodecylpyridin-1-ium (CSDP+) bromide alone or in combination with fluconazole with yeast and mammalian cells. We investigated cytotoxicity of the tested agents to mammalian HEK-293 cells and the influence of CSDP+ on the ability of C. albicans wt and a clinical isolate to adhere to HEK-293. Accumulation of lipophilic cation ethidium (Et+) was used to monitor the activity of efflux pumps in HEK-293 cells. The effect of CSDP+ on the expression of the main efflux transporter genes and transcription factors in C. albicans cells as well as HEK-293 efflux pump gene ABCB1 was determined. The study showed that CSDP+ alone and in combination with fluconazole was nontoxic to HEK-293 cells and was able to reduce C. albicans adhesion. The treatment of C. albicans cells with CSDP+ in combination with fluconazole resulted in a considerable overexpression of the MDR1 and MRR1 genes. The findings suggest that these genes could be associated with efflux-related resistance to fluconazole. Measurements of Et+ fluorescence and analysis of ABCB1 gene expression demonstrated that mammalian cells were not sensitive to concentrations of CSDP+ affecting C. albicans.

Effect of Some Disinfectant Solutions on the Adherence of Candida albicans to Three Types of Acrylic Resin Denture Base Materials

Objective: Microbial adhesion to denture surface is problematic for denture wearers, especially those with impaired dexterities. This study aimed to evaluate the effectiveness of two plant extracts (clove and Basil) in addition to Chlorhexidine on candida Albicans adherence to (heat, cold, light) activated acrylic denture base materials. 
 Methods: Two herbal extracted clove (Eugenia caryohyllata) and Basil (Ocimum basilicum) were prepared by drying, ground to powder, and extracted with ethanol chlorhexidine gluconate of 0.12% were used as three disinfectant solutions. One hundred and five square acrylic samples were prepared from (heat, cold, and light) activated acrylic resin denture base materials in dimensions of 10×10×2 mm for the study. The disk diffusion test was used to determine the susceptibility of C. Albicans to disinfectant solutions. The adhesion of yeast to the acrylic resin samples was measured with a light microscope by measuring the number of fungal cells in the corners of the square and expressed as no. of cells/mm2. Statistical analysis was done by ANOVA to compare the mean of readings between disinfectant solutions and post-hoc t-test in which the p-value is less than 0.05.
 Results: Statistically significant differences (p<0.05) of adhesion of C.albicans were found on the surfaces of three types of activated acrylic resin materials with means of 19.18, 46.25, and 26.50 cell/mm2on heat, light, and cold cure respectively and after immersing the specimens on the disinfectant solutions regarding the highest effect of the disinfectant solutions was seen in chlorhexidine gluconate of 0.12% which demonstrate 3.11, 5.89 and 5.43 cell/mm2 followed by Basil with means of 6.75, 13.57 and 10.11 cell/mm2 on heat, light and cold cure acrylic resin specimens correspondingly, then the clove and finally distilled water. 
 Conclusions: Both clove buds and basil leaves extracted solutions exhibited high antifungal activity besides Chlorhexidine on the surface of denture base materials. The highest inhibition zone was seen in Chlorhexidine, followed by Basil, clove, and distilled water, respectively. The number of fungal cell adhesion to the three types of denture base was decreased in the three disinfectant solutions when compared to distilled water (control group).

Double-layered acrylic resin denture base with nanoparticle additions: An in vitro study

Statement of problemWhether the addition of different antifungal nanoparticles to denture base materials may affect physical or esthetic properties of the resulting nanocomposite is unclear. PurposeThe purpose of this in vitro study was to determine how a new method of adding antifungal nanofiller affects the properties of the processed nanocomposite denture base material. Material and methodsHeat-polymerized acrylic resin specimens were prepared according to each test specification. Zirconium dioxide nanoparticles (ZrO2NPs) and silver nanoparticles (AgNPs) were added in 0.5, 1.0, and 1.5% of acrylic resin powder. The specimens were divided into 2 groups according to the acrylic resin packing method: 1 layer packed conventionally in one step and 2 layers packed in 2 steps, first with unmodified acrylic resin and then by a thin layer of modified acrylic resin before the final closure. The control group was made of unaltered acrylic resin in 1 step. Flexural strength (FS), translucency, and surface roughness (Ra) were measured. A microbial assay was performed by using the direct culture and slide count methods. Three-way ANOVA and Tukey post hoc tests were used to identify statistical differences among groups (α=.05). ResultsThe addition of ZrO2NPs and AgNPs in the 1- or 2-layer specimens reduced Candida albicans adhesion (P<.001). In the 1- and 2-layer specimens, FS significantly increased with ZrO2NPs. AgNPs decreased FS only in the 1-layer specimen (P<.001). Surface roughness was not changed for the 1- and 2-layer specimens with ZrO2NPs or the 1-layer specimen with 0.5% AgNPs (P>.05), while other AgNP groups exhibited increased surface roughness (P<.001). AgNPs significantly lowered translucency in the 1- and 2-layer specimens (P<.001), while ZrO2NPs decreased translucency only in the 1-layer specimen (P<.001). ConclusionsThe addition of ZrO2NPs in the double-layer technique decreased Candida adhesion and improved FS without affecting surface roughness, while AgNPs decreased Candida adhesion and FS and increased surface roughness. Both nanofillers decreased the translucency except 0.5% ZrO2NPs, which did not change translucency when applied in 2 layers.

Candida albicans adhesion to central venous catheters: Impact of blood plasma-driven germ tube formation and pathogen-derived adhesins

ABSTRACT Candida albicans-related bloodstream infections are often associated with infected central venous catheters (CVC) triggered by microbial adhesion and biofilm formation. We utilized single-cell force spectroscopy (SCFS) and flow chamber models to investigate the adhesion behavior of C. albicans yeast cells and germinated cells to naïve and human blood plasma (HBP)-coated CVC tubing. Germinated cells demonstrated up to 56.8-fold increased adhesion forces to CVC surfaces when compared to yeast cells. Coating of CVCs with HBP significantly increased the adhesion of 60-min germinated cells but not of yeast cells and 30-min germinated cells. Under flow conditions comparable to those in major human veins, germinated cells displayed a flow directional-orientated adhesion pattern to HBP-coated CVC material, suggesting the germ tip to serve as the major adhesive region. None of the above-reported phenotypes were observed with germinated cells of an als3Δ deletion mutant, which displayed similar adhesion forces to CVC surfaces as the isogenic yeast cells. Germinated cells of the als3Δ mutant also lacked a clear flow directional-orientated adhesion pattern on HBP-coated CVC material, indicating a central role for Als3 in the adhesion of germinated C. albicans cells to blood exposed CVC surfaces. In the common model of C. albicans, biofilm formation is thought to be mediated primarily by yeast cells, followed by surface-triggered the formation of hyphae. We suggest an extension of this model in which C. albicans germ tubes promote the initial adhesion to blood-exposed implanted medical devices via the germ tube-associated adhesion protein Als3.

Antifungal Efficacy and Physical Properties of Poly(methylmethacrylate) Denture Base Material Reinforced with SiO2 Nanoparticles.

To evaluate the effect of the addition of low concentration of silicon-dioxide nanoparticles (nano-SiO2 ) to poly(methylmethacrylate) (PMMA) denture base material on Candida albicans adhesion, surface roughness, contact angle, hardness, and translucency. A total of 150 acrylic disks were fabricated from heat-polymerized acrylic resin and specimens were divided into 3 groups of 50 per test. They were further subdivided into 5 subgroups (n = 10) according to the concentration of nano-SiO2 : control (no addition) and four tested groups modified with 0.05, 0.25, 0.5, and 1.0 wt% nano-SiO2 of acrylic powder. Slide count and direct culture methods were used to measure C. albicans count (CFU/mL). The surface roughness values (Ra ; μm) were determined using a profilometer. The contact angle (o ) measurement was performed by a goniometer using the sessile drop method. Vickers hardness was used to analyze surface hardness. Translucency was measured using a spectrophotometer. Data analysis was conducted through analysis of variance and Tukey's post hoc tests (α = 0.05). Compared to the control group, direct culture and slide count methods illustrated a significant decrease in C. albicans count (p ˂ 0.001) with the addition of nano-SiO2 , and this decrease was correlated with the concentration of nano-SiO2 . The addition of nano-SiO2 significantly decreased the contact angle (p ˂ 0.001), whereas hardness and surface roughness significantly increased (p ˂ 0.001). The addition of nano-SiO2 significantly decreased translucency (p ˂ 0.001), and this decrease was concentration dependent. Addition of low concentration of nano-SiO2 decreased C. albicans adhesion to PMMA denture base resin. Also, low additions of nano-SiO2 have positive effects on contact angle and hardness, whereas surface roughness and translucency were adversely affected at high concentrations.

Zymosan promotes proliferation, Candida albicans adhesion and IL-1\u03b2 production of oral squamous cell carcinoma in vitro

Oral squamous cell carcinoma (OSCC) is the most common type of head and neck squamous cell carcinoma (HNSCC), and the effect of zymosan (ZYM), a component of the yeast cell wall, on oral cancer remains unclear. The CCK-8 proliferation assay was performed to evaluate the effect of ZYM on the proliferation of the OSCC cell lines WSU-HN4, WSU-HN6 and CAL27, and the potential mechanism was explored by quantitative real-time PCR, immunofluorescence assay and western blot. A cell adhesion assay was conducted to determine the adhesion of Candida albicans to OSCC cells, and the expression of related genes, including TLR2, MyD88, NLRP3, ASC, Caspase-1 and IL-1β, and proteins, including TLR2, MyD88, NF-κB p65, p-NF-κB p65 and E-cadherin was determined. Additionally, the pro-inflammatory cytokines including IL-6, IL-8, TNF-α and IL-1β produced by OSCC cells were detected using a chemiluminescence immunoassay (CLIA). In the current study, the CCK-8 assay showed that ZYM promoted the proliferation of WSU-HN4, WSU-HN6 and CAL27 cells via the TLR2/MyD88 pathway. The cell adhesion assay showed that the number of C. albicans cells per field significantly increased in ZYM-treated OSCC cells compared to controls. When treated with ZYM, OSCC cells secreted significantly more pro-inflammatory cytokine IL-1β, which could enhance inflammation in oral cancer microenvironment. In conclusion, ZYM from the fungal cell wall promotes the proliferation, C. albicans adhesion and IL-1β production in OSCC, as demonstrated by in vitro experiments.

Effect of Silver Diamine Fluoride on Reducing Candida albicans Adhesion on Dentine.

Candida albicans is the most frequent pathogenic fungus in oral cavities. It adheres to dental tissues as part of dental plaques and contributes to caries formation. To evaluate the effect of silver diamine fluoride (SDF) on reducing C. albicans adhesion on dentine surfaces. Flat dentine surfaces were prepared from bovine dental disks, and samples were divided into three groups. The first and second groups were pretreated for 3min with 299mM or 2.99M SDF, respectively, and the third group (control) did not undergo any SDF pretreatment. All samples were washed, inoculated with C. albicans suspension onto their dentine surface, incubated at 30°C for 6h, and washed again to remove any nonadherent cells. The abundance of adherent cells was investigated using colorimetric and real-time polymerase chain reaction approaches. Subsequently, the morphological changes in C. albicans by pretreatment with SDF were observed under a scanning electron microscope (SEM). SDF inhibited candidal growth at concentrations as low as 2.99µM. Dentine disks pretreated with 299mM or 2.99M SDF displayed significantly fewer adhered cells as compared with the control group. Upon pretreatment with SDF, SEM images showed severe morphological changes in the cellular walls, in a dose-dependent manner, suggesting a fungicidal effect of SDF against the yeast. SDF should be considered for clinical applications aimed at inhibiting dental plaque caused by C. albicans, particularly in children and elderly individuals.

Candida albicans Mrv8, is involved in epithelial damage and biofilm formation

ABSTRACT Candida albicans is the most common human fungal pathogen that can cause superficial and deep-seated infections in susceptible individuals. Despite its medical importance, the vast majority of C. albicans genes remain of unknown function. Here, we report a role for the lineage-specific gene, MRV8, in host pathogen interactions, mycelial microcolony maturation and biofilm formation. In silico analysis indicated that MRV8 encodes a four-pass transmembrane protein unique to the closely related pathogens C. albicans and Candida dubliniensis. Deletion of MRV8 did not affect C. albicans adherence to, or initial invasion into human oral epithelia, but inhibited mycelial development and strongly reduced epithelial damage. mrv8Δ/Δ cells exhibited a media-dependent defect in biofilm formation and mutant biofilm metabolic activity was enhanced by cyclosporin A. mrv8Δ/Δ biofilms were more tolerant to treatment with caspofungin, but not to fluconazole or amphotericin B. Co-stimulation with calcium chloride and calcofluor white rescued biofilm growth in the presence of caspofungin, and this rescue-effect was Mrv8-dependent. Together, our data demonstrate an important role for a lineage-specific gene (MRV8) in C. albicans biofilm formation, drug tolerance and host–pathogen interactions.

Antimicrobial and protective effects of non-thermal plasma treatments on the performance of a resinous liner

ObjectiveOvercoming substantial shortcomings of soft liners as physico-chemical changes and liner-biofilm-related infections remains a challenge in the rehabilitation treatment. In this study, protective non-thermal plasma (NTP) treatments were developed on the soft liner surface to improve its surface and physico-chemical properties and to reduce fungal colonization after biofilm inhibition challenge. MethodsResinous liner specimens (Coe-Soft) were prepared and distributed in 3 groups according to the surface treatments: (1) untreated (control); (2) treated with sulfur hexafluoride-based NTP (SF6); and (3) treated with hexamethyldisiloxane-based NTP (HMDSO). To test the NTP stability and their protective and antimicrobial effect on the liner surface over time, the morphology, chemical composition, roughness, water contact angle, shore A hardness, sorption and solubility were evaluated before and after the specimens were exposed to dual-species biofilm of Candida albicans and Streptococcus oralis for 14 days. Colony forming units and biofilm structure were assessed. Data were submitted to ANOVA and Tukey tests (α = 0.05). Results: Both treatments modified the surface morphology, increased hydrophobicity and roughness of the liner, and were effective to reduce C. albicans adhesion without affecting the commensal health-associated S. oralis. HMDSO presented chemical stability and lower hardness in both periods, whereas SF6 exhibited higher initial hardness than control and the highest sorption; contrarily, similar solubility was noted for all groups. ConclusionHMDSO-based film showed improved physico-chemical properties and inhibited C. albicans biofilm. Thus, it has potential for use to control candida-related stomatitis and improve liner’s stability even after being exposed to biofilm inhibition challenge.

The effect of some antifungal agents and chlorhexidine on Candida albicans adherence on acrylic resin denture base surface (In vitro study)

The adherence of Candida albicans on acrylic resin denture base surface is co-nsidered as the first step in the pathogeni-city of candida–associated denture stoma-titis which is the most prevalent form of oral candidiasis in denture wearers. This study was an in vitro study aimed to eval-uate the anifungal effect of fluconazole, nystatin and chlorhexidine and their anti-adherent effect on Candida albicans cells that attached on the fitting surface of den-ture base. It was determined, using broth microdilution method at two concentra-tions for each drug, and the results were determined using spectrophotometer. All drugs had a highly significant antifungal effect on Candida albicans isolate at their two concentrations. The effect of saliva on the adherence of Candida albicans on the fitting surface of denture base was also considered. This study concluded the importance of saliva in increasing the microbial adherence; i.e., the mean number of adherent cells on ac-rylic resin samples in the absence of saliva was 7.4 + 1.9 cell/mm2 and with the pre-sence of saliva the number was 29.1 + 2.7 cells/mm2. The number of remaining adh-erent cells was counted using fluortescent microscope. The mean number of remain-ing cells which adhered on acrylic resin samples after the immersion in first con-centration fluconazole, nystatin and chlorhexidine for one hour respectively were 4, 5 and 2.6 cells/mm2 and for the second concentration/1 hour the numbers were 3.2, 4.1 and 1.7 cells/mm2 compared to the normal number of adherent cell 29.1 + 2.7 at p<0.01.

Evaluating the Antifungal Efficacy of Incorporating KappaCarrageenan Powder Into “Heat-Cured, Acrylic-Based Soft Denture Lining Material

Denture stomatitis is one of the serious problems that are related to the continuous use of soft lining material due to the accumulation of microorganisms. It is caused mainly by fungal growth, especially of Candida albicans. It, therefore, becomes necessary to examine the effectiveness of incorporating an antifungal drug into the soft lining material. This study was conducted to investigate the efficacy of adding the kappa-carrageenan powder to heat-cured, acrylic-based soft lining material against Candida albicans adherence. A pilot study was performed to decide the best concentration of kappa-carrageenan to be used with the heatcured, acrylic-based soft liner. Five percentages by weight of kappa-carrageenan powder (0.5, 1, 1.5, 2, and 2.5wt.%) were evaluated and compared with the control group (0wt.%). The Candida albicans adherence test was performed to assess the efficacy of kappa-carrageenan powder in preventing the adherence of Candida albicans. Results showed the 1.5wt.% and 2wt.% groups as having the best effect. The main study included preparing thirty samples and dividing them into three groups based on the percentage of powder of kappa-carrageenan added to the heat-cured acrylic-based soft lining material (control: 0wt.%; experimental: 1.5wt.% and 2wt.%). The purpose of performing Candida albicans adherence test was to evaluate the antifungal efficacy of kappa-carrageenan powder addition, and all the resulted data were analysed using “one-way analysis of variance (ANOVA) and Dunnet T3 post-hoc test at a significance level of p&lt;0.05”. The results of Candida albicans adherence test revealed a highly significant decrease in the values of the adhered Candida albicans cells after incorporation of 1.5wt.% and 2wt.% of kappa-carrageenan powder when compared to the control group (p&lt;0.01). The result of this study suggests that the addition of kappa-carrageenan powder is an effective drug against Candida albicans adherence on the surface of the heat-cured acrylic-based soft lining material, and the addition of 2wt.% is more effective than 1.5wt.%.

Antifungal Activity of Magnesium Oxide Nanoparticles: Effect on the Growth and Key Virulence Factors of Candida albicans.

The aim of this research was to study the effects of different concentrations of magnesium oxide nanoparticles (MgO NPs) on the growth and key virulence factors of Candida albicans (C. albicans). The minimum inhibitory concentration (MIC) of MgO NPs against C. albicans was determined by the micro-broth dilution method. A time-kill curve of MgO NPs and C. albicans was established to investigate the ageing effect of MgO NPs on C. albicans. Crystal violet staining, the MTT assay, and inverted fluorescence microscopy were employed to determine the effects of MgO NPs on C. albicans adhesion, two-phase morphological transformation, biofilm biomass, and metabolic activity. The time-kill curve showed that MgO NPs had fungicidal and antifungal activity against C. albicans in a time- and concentration-dependent manner. Semi-quantitative crystal violet staining and MTT assays showed that MgO NPs significantly inhibited C. albicans biofilm formation and metabolic activity, and the difference was statistically significant (p < 0.001). Inverted fluorescence microscopy showed that MgO NPs could inhibit the formation of C. albicans biofilm hyphae. Adhesion experiments showed that MgO NPs significantly inhibited the initial adhesion of C. albicans (p < 0.001). This study demonstrates that MgO NPs can effectively inhibit the growth, initial adhesion, two-phase morphological transformation, and biofilm formation of C. albicans and is an antifungal candidate.

The Role of 17β-Estrogen in Candida albicans Adhesion on Human Vaginal Epithelial Cells via FAK Phosphorylation.

To investigate the role of 17β-estrogen in Candida albicans (C. albicans) adhesion on human vaginal epithelial cells in vulvovaginal candidiasis (VVC). The vaginal epithelial cell line, VK2/E6E7, was used to study the estrogen-induced molecular events between C. albicans and cells. An adhesion study was performed to evaluate the involvement of the estrogen-dependent focal adhesion kinase (FAK) activation in cell adhesion. The phosphorylation status of FAK and estrogen receptor α (ERα) upon estrogen challenge was assessed by western blotting. Specific inhibitors for ERα were used to validate the involvement of ERα-FAK signaling cascade. A transient activation of ERα and FAK was observed following the stimulation with 1000nM estrogen for 48h, as well as the increased average number of C. albicans adhering to each vaginal epithelial cell. Estrogen-induced activation of ERa and FAK was inhibited by the specific inhibitor of ERα, especially when the inhibitor reached a 10μM concentration and allowed to act for 12h. Simultaneously, a decrease in the number of adherent C. albicans was observed. However, this inhibitory effect diminished as the concentration of estrogen increased. FAK and ERα signaling cascades were involved in the early interaction between the vaginal epithelial cells and C. albicans, which appeared to be linked with the enhanced cell adhesion leading to VVC and promoted by a certain concentration of estrogen.

АНАЛИЗ ВЫРАЖЕННОСТИ МИКРОБНОЙ АДГЕЗИИ ПАТОГЕННЫХ ГРИБОВ С. ALBICANS НА ПОВЕРХНОСТИ ТЕРМОПЛАСТИЧЕСКОГО МАТЕРИАЛА ДЛЯ ОРТОПЕДИЧЕСКИХ КОНСТРУКЦИЙ

Subject: The paper deals with measured biomedical characteristics of samples of a prosthodontic thermoplastic polymer, in regards to certain potentially pathogenic species of oral microflora. Evaluation and comparative analysis of С. albicans adhesion and colonization activity on the prosthodontic material surface were undertaken.&#x0D; Materials and methods: The research used the following reference strains: C. albicans, S. aureus, S. epidermidis and Escherichia coli. The biofilms were visualized by means of a plate reader, PowerWave X (USA) after staining with 0.1% aqueous solution of gentian violet and alcohol extraction of the dye. The bacteria were tested for viability by direct inoculation of selective media.&#x0D; Results: С. albicans was found to produce a more prominent film on the thermoplastic polymer than other potentially pathogenic microorganisms.&#x0D; Conclusions: Satisfactory biomedical characteristics of the thermoplastic material allow it to be used for prosthodontic purposes.

Candida albicans aspects of binary titanium alloys for biomedical applications.

Titanium and its alloys are widely used in biomedical devices, e.g. implants, due to its biocompatibility and osseointegration ability. In fact, fungal (Candida spp.) infection has been identified as one of the key reasons causing the failure of the device that is inevitable and impactful to the society. Thus, this study evaluated the surface morphology, surface chemical composition and Candida albicans adhesion on specimens of 16 binary Ti-alloys (∼5 wt% of any one of the alloy elements: Ag, Al, Au, Co, Cr, Cu, Fe, In, Mn, Mo, Nb, Pd, Pt, Sn, V and Zr) compared with cp-Ti, targeting to seek for the binary Ti-alloys which has the lowest C. albicans infection. Candida albicans cultures were grown on the specimens for 48 h, and colony forming units (CFUs) and real-time polymerase chain reaction (RT-PCR) were used to evaluate the biofilm formation ability. Scanning electron microscopy and confocal laser scanning microscopy confirmed the formation of C. albicans biofilm on all specimens’ surfaces, such that CFU results showed Ti-Mo, Ti-Zr, Ti-Al and Ti-V have less C. albicans formed on the surfaces than cp-Ti. RT-PCR showed Ti-Zr and Ti-Cu have significantly higher C. albicans DNA concentrations than Ti-Al and Ti-V (P < 0.05), whereas Ti-Cu has even showed a statistically higher concentration than Ti-Au, Ti-Co, Ti-In and Ti-Pt (P < 0.05). This study confirmed that Ti-Mo, Ti-Zr, Ti-Al and Ti-V have lower the occurrence of C. albicans which might be clinically advantageous for medical devices, but Ti-Cu should be used in caution.

Effect of Silicon dioxide coating of acrylic resin surfaces on Candida albicans adhesion.

Acrylic resin has been used in the manufacture of prostheses, however, in the oral cavity, this material starts to retain microorganisms capable of causing gingival inflammation due its porosities. The aim of this study was to evaluate the influence of the use of silicon dioxide as a coating layer applied onto acrylic resin, on the adhesion of Candida albicans (Ca). After the incubation period in Sabouraud Dextrose Broth, a total of 1 ml of the Ca suspension was added to plate wells, each well containing a specimen of acrylic resin. The adhesion ability of Ca on acrylic resin was determined by counting colonies. Three groups (n = 6) of acrylic resin were assessed: with polishing (RP); without polishing (RW); with polishing and coating layer of silicon dioxide (RPC). Ca deposited on the surface of the acrylic resin was also observed using Scanning Electron Microscopy (SEM). Statistical assessment by Kruskal-Wallis and Student-Newman-Keuls Method were done (α = 2%). There was significant difference among the groups. The RPC group showed the lowest growth, with an average of 5.59 Log CFU/cm 2 ; there was a statistically significant difference in relation to group RW, which presented a growth of 6.07 Log CFU/cm 2 and to group RP with 5.91 Log CFU/cm 2 (p < 000.1). SEM images demonstrated that in the RP and RPC group, the surface of the resin had greater regularity, and smaller number of microorganisms. The application of silicon dioxide coating on acrylic resin appears to be a promising alternative, and its use can help in reducing the adhesion of Ca in prostheses.

Biyoaktif Cam ve Nano-Çinko Silisyum Kompleksi İçeren Kompozit Rezinlerin Candida Albicans Adezyonu Açısından Karşılaştırılması

Biyoaktif Cam ve Nano-Çinko Silisyum Kompleksi İçeren Kompozit Rezinlerin Candida Albicans Adezyonu Açısından Karşılaştırılması

Polishing characteristics of polyetherketoneketone on Candida albicans adhesion

Polishing characteristics of polyetherketoneketone on <i>Candida albicans</i> adhesion