scholarly journals Preliminary study into the effects of tobacco smoke on Candida albicans

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Megan Williams ◽  
Siôn Edwards ◽  
Ian Fallis ◽  
Melanie Wilson ◽  
David Bradshaw ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Untreated Control ◽  
Laser Scanning ◽  
Artificial Saliva ◽  
Virulence Gene ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Calcofluor White ◽  
Denture Stomatitis ◽  
Virulence Gene Expression

Background: Denture-stomatitis (DS) is the most common form of oral candidosis with increased prevalence in cigarette smokers (Akram et al. 2018). Interestingly, tobacco condensate (TC) increases Candida albicans adhesion, growth, biofilm-formation, virulence gene expression (Semlali et al. 2014)and hyphal production (Awad and Karuppayil 2018). We hypothesised that TC-treated denture acrylic would therefore affect C. albicans within acrylic biofilms. Methods: Acrylic discs (pre-conditioned with TC, artificial saliva (AS) or water) were incubated at 37°C with C. albicans (n=6) for 90 min or 24 h. Adherent Candida were stained with calcofluor white and confocal laser scanning microscopy (CLSM) used to assess levels of adherence, biofilm and hyphal numbers. Expressed virulence genes (n=7) were measured by qPCR. Results: CLSM showed that effects of TC-treatment were strain dependent. Adherence of C. albicans PTR/94 to TC-treated surfaces was significantly (P<0.002) lower than on the untreated control. Biofilm levels of PTR/94 after 24 h were found to be significantly higher on AS-treated acrylic than the TC-treated and untreated control. Five strains had significantly fewer filamentous forms after 90 min on TC-treated surfaces. TC-treatment promoted hyphal levels for strain 705/93 after 24h. Conclusion: TC pre-conditioning altered adherence and biofilm coverage of C. albicans to acrylic surfaces and influenced hyphal development. Work is ongoing to ascertain the significance of these effects on C. albicans pathogenicity. Akram et al. (2018). Journal of Oral Science 60(1):115–120. Awad and Karuppayil (2018). American Journal of Clinical Microbiology and Antimicrobials1(3):1–6. Semlali et al. (2014). BMC Microbiology. 14:61

Is there an optimal method to detach Candida albicans biofilm from dental materials?

2021 ◽  
Vol 70 (10) ◽  
Author(s):  
Gustavo S. Moraes ◽  
Victoria S. Cachoeira ◽  
Fernanda M. C. Alves ◽  
Falyne Kiratcz ◽  
Thaís Albach ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Laser Scanning ◽  
Dental Materials ◽  
Laser Scanning Microscopy ◽  
Aetiological Factor ◽  
Confocal Laser ◽  
Optimal Method ◽  
Denture Base ◽  
Denture Stomatitis ◽  
Significant Difference

Introduction. Candida albicans can produce a complex, dynamic and resistant biofilm on the surface of dental materials, especially denture base acrylic resins and temporary soft liners. This biofilm is the main aetiological factor for denture stomatitis, an oral inflammatory condition characterized by chronic and diffuse erythema and oedema of the denture bearing mucosa. Gap Statement. There is no consensus in the literature regarding the best method to detach biofilms from dental materials. In order to assess the antifungal efficacy of new materials and treatments, the biofilm needs to be properly detached and quantified. Aim. This study compared different methods of detaching C. albicans biofilm from denture base acrylic resin (Vipi Cril) and temporary soft liner (Softone) specimens. Methodology. Specimens of each material were immersed in an inoculum of C. albicans SC5314 and remained for 90 min in orbital agitation at 75 r.p.m. and 37 °C. After the removal of non-adherent cells, the specimens were immersed in RPMI-1640 medium for 48 h. Biofilm formation was evaluated with confocal laser scanning microscopy (n=5). Then, other specimens (n=7) were fabricated, contaminated and immersed in 3 ml of sterile phosphate-buffered saline (PBS) and vortexed or sonicated for 1, 2, 5, or 10 min to detach the biofilm. The quantification of detached biofilm was performed by colony-forming unit (c.f.u.) ml−1 count. Results were submitted to one-way analysis of variance (ANOVA)/Tukey HSD test (α=0.05). Results. A mature and viable biofilm was observed on the surfaces of both materials. For both materials, there was no significant difference (P>0.05) among detachment methods. Conclusion. Any of the tested methods could be used to detach C. albicans biofilm from hard and soft acrylic materials.

Effect of Calcium-phosphate Desensitizers on Staining Susceptibility of Acid-eroded Enamel

2019 ◽  
Vol 44 (3) ◽  
pp. 281-288 ◽  
Author(s):  
KY Kyaw ◽  
M Otsuki ◽  
MS Segarra ◽  
N Hiraishi ◽  
J Tagami
Keyword(s):  
Surface Roughness ◽  
Calcium Phosphate ◽  
Repeated Measures ◽  
Laser Scanning ◽  
Artificial Saliva ◽  
Color Difference ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Control Group ◽  
Before And After

SUMMARY Objective: To investigate the effect of calcium-phosphate–based desensitizers, Teethmate AP paste (TMAP) and Teethmate Desensitizer (TMD) (Kuraray Noritake Dental, Tokyo, Japan), on the prevention of staining on acid-eroded enamel. Methods and Materials: Forty polished enamel samples (4×4×1 mm) from bovine incisors were randomly divided into five groups (n=8). After immersion in 50 mL of 0.5% citric acid (pH 2.5) for 15 minutes to form acid-eroded surfaces, the surfaces were subjected to different treatments with TMAP, TMD, and NaF (0.21% means 950 ppm) for five minutes. Another eroded group was not treated with desensitizer. For the control group, the samples were not eroded or treated. All the samples were stored in artificial saliva (AS) at pH 7.2 for 24 hours at 37°C. The TMAP, TMD, or NaF was reapplied at eight and 16 hours during the 24 hours of storage time. The surface roughness (Sa) was evaluated following ISO 25178 for surface texture using confocal laser scanning microscopy (VK-X 150 series, Keyence, Osaka, Japan) before acid erosion, after acid erosion, and after 24 hours of incubation in AS. Afterward, the color difference was measured with a dental colorimeter (Shade Eye NCC, Shofu, Kyoto, Japan) before and after staining with tea solution. Results: One-way repeated measures analysis of variance showed that acid erosion significantly increased Sa (p&lt;0.001). TMAP- and TMD-treated groups exhibited lower Sa values than the NaF group and the no-desensitizer treatment group. The greatest staining was observed in the NaF group and the no-desensitizer group, while the TMAP and TMD groups significantly decreased the formation of stains. Conclusions: Acid-eroded enamel increased surface roughness and tended to absorb more stains. However, the application of TMAP and TMD moderated the roughness and thus prevented the formation of extrinsic stains.

scholarly journals Antibody response to the 45 kDa Candida albicans antigen in an animal model and potential role of the antigen in adherence

2008 ◽  
Vol 57 (12) ◽  
pp. 1466-1472 ◽  
Author(s):  
Helena Bujdáková ◽  
Ema Paulovičová ◽  
Silvia Borecká-Melkusová ◽  
Juraj Gašperík ◽  
Soňa Kucharíková ◽  
...  
Keyword(s):  
Animal Model ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Vaccine Development ◽  
Laser Scanning Microscopy ◽  
Model Systems ◽  
Confocal Laser

The Candida antigen CR3-RP (complement receptor 3-related protein) is supposed to be a ‘mimicry’ protein because of its ability to bind antibody directed against the α subunit of the mammalian CR3 (CD11b/CD18). This study aimed to (i) investigate the specific humoral isotypic response to immunization with CR3-RP in vivo in a rabbit animal model, and (ii) determine the role of CR3-RP in the adherence of Candida albicans in vitro using the model systems of buccal epithelial cells (BECs) and biofilm formation. The synthetic C. albicans peptide DINGGGATLPQ corresponding to 11 amino-acids of the CR3-RP sequence DINGGGATLPQALXQITGVIT, determined by N-terminal sequencing, was used for immunization of rabbits to obtain polyclonal anti-CR3-PR serum and for subsequent characterization of the humoral isotypic response of rabbits. A significant increase of IgG, IgA and IgM anti-CR3-RP specific antibodies was observed after the third (P<0.01) and the fourth (P<0.001) immunization doses. The elevation of IgA levels suggested peptide immunomodulation of the IgA1 subclass, presumably in coincidence with Candida epithelial adherence. Blocking CR3-RP with polyclonal anti-CR3-RP serum reduced the ability of Candida to adhere to BECs, in comparison with the control, by up to 35 % (P<0.001), and reduced biofilm formation by 28 % (P<0.001), including changes in biofilm thickness and integrity detected by confocal laser scanning microscopy. These properties of CR3-RP suggest that it has potential for future vaccine development.

scholarly journals Antimicrobial Activity Evaluation on Silver Doped Hydroxyapatite/Polydimethylsiloxane Composite Layer

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
C. S. Ciobanu ◽  
A. Groza ◽  
S. L. Iconaru ◽  
C. L. Popa ◽  
P. Chapon ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Photoelectron Spectroscopy ◽  
Laser Scanning ◽  
Composite Layer ◽  
Physicochemical Characterization ◽  
Antimicrobial Effect ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Composite Layers

The goal of this study was the preparation, physicochemical characterization, and microbiological evaluation of novel hydroxyapatite doped with silver/polydimethylsiloxane (Ag:HAp-PDMS) composite layers. In the first stage, the deposition of polydimethylsiloxane (PDMS) polymer layer on commercially pure Si disks has been produced in atmospheric pressure corona discharges. Finally, the new silver doped hydroxyapatite/polydimethylsiloxane composite layer has been obtained by the thermal evaporation technique. The Ag:HAp-PDMS composite layers were characterized by various techniques, such as Scanning Electron Microscopy (SEM), Glow Discharge Optical Emission Spectroscopy (GDOES), and X-ray photoelectron spectroscopy (XPS). The antimicrobial activity of the Ag:HAp-PDMS composite layer was assessed againstCandida albicansATCC 10231 (ATCC—American Type Culture Collection) by culture based and confirmed by SEM and Confocal Laser Scanning Microscopy (CLSM) methods. This is the first study reporting the antimicrobial effect of the Ag:HAp-PDMS composite layer, which proved to be active againstCandida albicansbiofilm embedded cells.

scholarly journals Bioceramic Layers with Antifungal Properties

Coatings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 276 ◽  
Author(s):  
Daniela Predoi ◽  
Simona Iconaru ◽  
Mihai Predoi
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Laser Scanning ◽  
Sol Gel ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
X Ray Diffraction ◽  
Composite Layers ◽  
Constituent Elements ◽  
Microbial Strain

The sol-gel method was used to synthesize the silver doped hydroxyapatite (Ag:HAp) gels in order to produce the antifungal composite layers. The pure Ti disks were used as the substrate for the composite layers. Important information about suspensions used to make Ag:HAp composite layers were obtained from an ultrasonic technique. The identification of the phase composition of the Ag:HAp composite layers was accomplished X-ray diffraction (XRD). The morphology and the thickness of the layers was evaluated using scanning electron microscopy (SEM). The uniform distribution of the constituent elements (Ag, Ca, P, and O) in both analyzed samples was observed. The antifungal activity of the samples against Candida albicans ATCC 10231 microbial strain were investigated immediately after their preparation and six months later. SEM and confocal laser scanning microscopy (CLSM) images showed that the composite layers at the two time intervals exhibited a strong antifungal activity against Candida albicans ATCC 10231 and completely inhibited the biofilm formation.

Visualization of Microbiological Processes Underlying Stress Relaxation inPseudomonas aeruginosaBiofilms

2014 ◽  
Vol 20 (3) ◽  
pp. 912-915 ◽  
Author(s):  
Brandon W. Peterson ◽  
Henk J. Busscher ◽  
Prashant K. Sharma ◽  
Henny C. van der Mei
Keyword(s):  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Extracellular Polymeric Substances ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser ◽  
Calcofluor White ◽  
Microbiological Processes ◽  
Green Fluorescent

AbstractBacterial biofilms relieve themselves from external stresses through internal rearrangement, as mathematically modeled in many studies, but never microscopically visualized for their underlying microbiological processes. The aim of this study was to visualize rearrangement processes occurring in mechanically deformed biofilms using confocal-laser-scanning-microscopy after SYTO9 (green-fluorescent) and calcofluor-white (blue-fluorescent) staining to visualize bacteria and extracellular-polymeric matrix substances, respectively. We apply 20% uniaxial deformation toPseudomonas aeruginosabiofilms and fix deformed biofilms prior to staining, after allowing different time-periods for relaxation. Two isogenicP. aeruginosastrains with different abilities to produce extracellular polymeric substances (EPS) were used. By confocal-laser-scanning-microscopy all biofilms showed intensity distributions for fluorescence from which rearrangement of EPS and bacteria in deformed biofilms were derived. For theP. aeruginosastrain producing EPS, bacteria could not find new, stable positions within 100 s after deformation, while EPS moved toward deeper layers within 20 s. Bacterial rearrangement was not seen inP. aeruginosabiofilms deficient in production of EPS. Thus, EPS is required to stimulate bacterial rearrangement in mechanically deformed biofilms within the time-scale of our experiments, and the mere presence of water is insufficient to induce bacterial movement, likely due to its looser association with the bacteria.

scholarly journals Enzymatic Preparation and Characterization of Spherical Microparticles Composed of Artificial Lignin and TEMPO-Oxidized Cellulose Nanofiber

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 917
Author(s):  
Naoya Fukuda ◽  
Mayumi Hatakeyama ◽  
Takuya Kitaoka
Keyword(s):  
Laser Scanning ◽  
Aqueous Suspension ◽  
Cellulose Nanofibers ◽  
Coniferyl Alcohol ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Oxidized Cellulose ◽  
Natural Polymers ◽  
Calcofluor White ◽  
Spherical Microparticles

A one-pot and one-step enzymatic synthesis of submicron-order spherical microparticles composed of dehydrogenative polymers (DHPs) of coniferyl alcohol as a typical lignin precursor and TEMPO-oxidized cellulose nanofibers (TOCNFs) was investigated. Horseradish peroxidase enzymatically catalyzed the radical coupling of coniferyl alcohol in an aqueous suspension of TOCNFs, resulting in the formation of spherical microparticles with a diameter and sphericity index of approximately 0.8 μm and 0.95, respectively. The ζ-potential of TOCNF-functionalized DHP microspheres was about −40 mV, indicating that the colloidal systems had good stability. Nanofibrous components were clearly observed on the microparticle surface by scanning electron microscopy, while some TOCNFs were confirmed to be inside the microparticles by confocal laser scanning microscopy with Calcofluor white staining. As both cellulose and lignin are natural polymers known to biodegrade, even in the sea, these woody TOCNF−DHP microparticle nanocomposites were expected to be promising alternatives to fossil resource-derived microbeads in cosmetic applications.

scholarly journals Effects of lipid emulsions on the formation of Escherichia coli–Candida albicans mixed-species biofilms on PVC

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shanshan Li ◽  
Wanshi Duan ◽  
Yujie Lei ◽  
Zhonghui Wang ◽  
Chaojiang Fu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Candida Albicans ◽  
Laser Scanning ◽  
Bloodstream Infections ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Lipid Emulsions ◽  
Mixed Species ◽  
E Coli ◽  
Increased Risk

AbstractPatients receiving lipid emulsions are at increased risk of contracting catheter-related bloodstream infections (CRBSIs) in the clinic. More than 15% of CRBSIs are polymicrobial. The objective of this study was to explore the effects of lipid emulsions on the formation of Escherichia coli (E. coli)–Candida albicans (C. albicans) mixed-species biofilms (BFs) on polyvinyl chloride (PVC) surfaces and the underlying mechanism. Mixed-species BFs were produced by coculturing E. coli and C. albicans with PVC in various concentrations of lipid emulsions. Crystal violet staining and XTT assays were performed to test the mixed-species BF biomass and the viability of microbes in the BFs. The microstructures of the BFs were observed by an approach that combined confocal laser scanning microscopy, fluorescence in situ hybridization, and scanning electron microscopy. The study found that lipid emulsions could promote the formation of E. coli–C. albicans mixed-species BFs, especially with 10% lipid emulsions. The mechanism by which lipid emulsions promote mixed-species BF formation may involve significant upregulation of the expression of the flhDC, iha, HTA1, and HWP1 genes, which are associated with bacterial motility, adhesion, and BF formation. The results derived from this study necessitate strict aseptic precautions when handling lipid emulsions and avoiding the use of high concentrations of lipid emulsions for as long as possible.

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