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

2020 ◽  
Vol 20 (5) ◽  
Author(s):  
Anna Carolina Borges Pereira Costa ◽  
Graziella Nuernberg Back-Brito ◽  
François L Mayer ◽  
Bernhard Hube ◽  
Duncan Wilson
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Transmembrane Protein ◽  
Specific Gene ◽  
Host Pathogen Interactions ◽  
Calcofluor White ◽  
Biofilm Growth ◽  
Epithelial Damage ◽  
Host Pathogen ◽  
Lineage Specific Gene

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.

scholarly journals Candida albicans Sun41p, a Putative Glycosidase, Is Involved in Morphogenesis, Cell Wall Biogenesis, and Biofilm Formation

2007 ◽  
Vol 6 (11) ◽  
pp. 2056-2065 ◽  
Author(s):  
Ekkehard Hiller ◽  
Sonja Heine ◽  
Herwig Brunner ◽  
Steffen Rupp
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Cell Monolayer ◽  
The Sun ◽  
Calcofluor White ◽  
Cellular Processes ◽  
Cell Wall Biogenesis ◽  
Reduced Adherence ◽  
Higher Sensitivity

ABSTRACT The SUN gene family has been defined in Saccharomyces cerevisiae and comprises a fungus-specific family of proteins which show high similarity in their C-terminal domains. Genes of this family are involved in different cellular processes, like DNA replication, aging, mitochondrial biogenesis, and cytokinesis. In Candida albicans the SUN family comprises two genes, SUN41 and SIM1. We demonstrate that C. albicans mutants lacking SUN41 show similar defects as found for S. cerevisiae, including defects in cytokinesis. In addition, the SUN41 mutant showed a higher sensitivity towards the cell wall-disturbing agent Congo red, whereas no difference was observed in the presence of calcofluor white. Compared to the wild type, SUN41 deletion strains exhibited a defect in biofilm formation, a reduced adherence on a Caco-2 cell monolayer, and were unable to form hyphae on solid medium under the conditions tested. Interestingly, Sun41p was found to be secreted in the medium of cells growing as blastospores as well as those forming hyphae. Our results support a function of SUN41p as a glycosidase involved in cytokinesis, cell wall biogenesis, adhesion to host tissue, and biofilm formation, indicating an important role in the host-pathogen interaction.

scholarly journals Improvement of XTT assay performance for studies involving Candida albicans biofilms

2008 ◽  
Vol 19 (4) ◽  
pp. 364-369 ◽  
Author(s):  
Wander José da Silva ◽  
Jayampath Seneviratne ◽  
Nipuna Parahitiyawa ◽  
Edvaldo Antonio Ribeiro Rosa ◽  
Lakshman Perera Samaranayake ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Cell Activity ◽  
Growth Yield ◽  
Xtt Assay ◽  
Biofilm Growth ◽  
Assay Performance ◽  
Reduction Assay ◽  
Cell Layers ◽  
Biofilm Development

2, 3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide (XTT) reduction assay has been used to study Candida biofilm formation. However, considering that the XTT reduction assay is dependent on cell activity, its use for evaluating mature biofilms may lead to inaccuracies since biofilm bottom cell layers tend to be relatively quiescent at later stages of biofilm formation. The aim of this study was to improve XTT reduction assay by adding glucose supplements to the standard XTT formulation. Candida albicans ATCC 90028 was used to form 24-, 48- and 72-h biofilms. The oxidative activity at 90, 180 and 270 min of incubation was evaluated. The control consisted of standard XTT formulation without glucose supplements, and was modified by the addition of 50, 100 and 200 mM of glucose. The XTT assay with 200 mM glucose showed more accurate and consistent readings correlating with biofilm development at 24, 48 and 72 h. Biofilm growth yield after 180 min incubation, when evaluated with the 200 mM glucose supplemented XTT, produced the most consistent readings on repetitive testing. It may be concluded that glucose supplementation of XTT could minimize variation and produce more accurate data for the XTT assay.

scholarly journals Disparate Candida albicans Biofilm Formation in Clinical Lipid Emulsions Due to Capric Acid-Mediated Inhibition

2019 ◽  
Vol 63 (11) ◽  
Author(s):  
Hubertine M. E. Willems ◽  
Jeremy S. Stultz ◽  
Molly E. Coltrane ◽  
Jabez P. Fortwendel ◽  
Brian M. Peters
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Bloodstream Infections ◽  
Capric Acid ◽  
Lipid Emulsions ◽  
Biofilm Growth ◽  
Content Type ◽  
Biofilm Model ◽  
Hypha Formation

ABSTRACT Receipt of parenteral nutrition (PN) remains an independent risk factor for developing catheter-related bloodstream infections (CR-BSI) caused by fungi, including by the polymorphic fungus Candida albicans, which is notoriously adept at forming drug-resistant biofilm structures. Among a variety of macronutrients, PN solutions contain lipid emulsions to supply daily essential fats and are often delivered via central venous catheters (CVCs). Therefore, using an in vitro biofilm model system, we sought to determine whether various clinical lipid emulsions differentially impacted biofilm growth in C. albicans. We observed that the lipid emulsions Intralipid and Omegaven both stimulated C. albicans biofilm formation during growth in minimal medium or a macronutrient PN solution. Conversely, Smoflipid inhibited C. albicans biofilm formation by approximately 50%. Follow-up studies revealed that while Smoflipid did not impair C. albicans growth, it did significantly inhibit hypha formation and hyphal elongation. Moreover, growth inhibition could be recapitulated in Intralipid when supplemented with capric acid—a fatty acid present in Smoflipid but absent in Intralipid. Capric acid was also found to dose dependently inhibit C. albicans biofilm formation in PN solutions. This is the first study to directly compare different clinical lipid emulsions for their capacity to affect C. albicans biofilm growth. Results derived from this study necessitate further research regarding different lipid emulsions and rates of fungus-associated CR-BSIs.

scholarly journals Adhesion and biofilm formation of Candida albicans on native and Pluronic-treated polystyrene

Biofilms ◽  
2005 ◽  
Vol 2 (1) ◽  
pp. 63-71 ◽  
Author(s):  
K. E. Wesenberg-Ward ◽  
B. J. Tyler ◽  
J. T. Sears
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Pluronic F127 ◽  
Artificial Organs ◽  
Confocal Scanning Laser Microscopy ◽  
Mechanical Trauma ◽  
Biofilm Growth ◽  
Prosthetic Devices ◽  
Initial Adhesion ◽  
Defined Culture

Candida albicans forms part of the normal human flora whose growth is usually restricted by the normal flora bacteria and the host's immune system. It is an opportunistic fungal pathogen that causes infections in immunocompromised individuals, mechanical trauma victims and iatrogenic patients. Candida albicans can ingress the human host by adhering to a plastic surface (i.e. prosthetic devices, catheters, artificial organs, etc.) that is subsequently implanted, and forms a protective biofilm that provides a continuous reservoir of yeast to be hematogenously dispersed. In order for the medical profession to battle device-related infections, initial adhesion and biofilm formation of C. albicans needs to be better understood. There has been some skepticism as to whether the initial adhesion events bear any relationship to subsequent biofilm formation. Thus, to better comprehend the relationship between the initial adhesion rates and growth rate and biofilm formation, these events were studied on two different, well-defined culture surfaces, native polystyrene and Pluronic F127-conditioned polystyrene. The adhesion studies determined that Pluronic F127 adsorption dramatically reduced the adhesion of C. albicans to polystyrene. The biofilm growth studies, analyzed by confocal scanning laser microscopy, revealed that Pluronic F127 decreased the biofilm surface coverage, cluster group size, thickness and the presence of hyphal elements over the untreated polystyrene. These findings indicate that the effect of a material's surface chemistry on the initial adhesion process has a direct influence on subsequent biofilm formation.

Candida albicans proteinases and host/pathogen interactions

2004 ◽  
Vol 6 (10) ◽  
pp. 915-926 ◽  
Author(s):  
Julian Naglik ◽  
Antje Albrecht ◽  
Oliver Bader ◽  
Bernhard Hube
Keyword(s):  
Candida Albicans ◽  
Host Pathogen Interactions ◽  
Host Pathogen

scholarly journals CO2 accelerates Candida albicans biofilm formation and reveals novel approaches to their inhibition on airway management devices

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Campbell W Gourlay ◽  
Fritz A Muhlschlegel ◽  
Daniel R Pentland
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Environmental Cues ◽  
Exhaled Breath ◽  
Forming Process ◽  
Biofilm Growth ◽  
Human Fungal Pathogen ◽  
Nutritional Immunity ◽  
Significant Extension ◽  
Dimorphic Yeast

C. albicans is the predominant human fungal pathogen worldwide and frequently colonises medical devices, such as voice prosthesis, as a biofilm. It is a dimorphic yeast that can switch between yeast and hyphal forms in response to environmental cues, a property that is essential during biofilm establishment and maturation. One such cue is elevation of CO2 levels, as observed in exhaled breath for example. However, despite the clear medical relevance the effects of high CO2 levels on C. albicans biofilm growth has not been investigated to date. Here, we show that 5% CO2 significantly enhances each stage of the C. albicans biofilm forming process; from attachment through maturation to dispersion, via stimulation of the Ras/cAMP/PKA signalling pathway. Transcriptome analysis of biofilm formation under elevated CO2 conditions revealed the activation of key biofilm formation pathways governed by the central biofilm regulators Efg1, Brg1, Bcr1 and Ndt80. Biofilms grown in under elevated CO2 conditions also exhibit increases in azole resistance, tolerance to nutritional immunity and enhanced glucose uptake capabilities. We thus characterise the mechanisms by which elevated CO2 promote C. albicans biofilm formation. We also investigate the possibility of re-purposing drugs that can target the CO2 activated metabolic enhancements observed in C. albicans biofilms. Using this approach we can significantly reduce multi-species biofilm formation in a high CO2 environment and demonstrate a significant extension of the lifespan of voice prostheses in a patient trial. Our research demonstrates a bench to bedside approach to tackle Candida albicans biofilm formation.

scholarly journals A modified crystal violet assay is comparable to XTT reduction assay for quantification of biofilm formation by Candida albicans

2020 ◽  
Author(s):  
Yue Qu ◽  
Shoufeng Yang ◽  
Zhangzhang Chen ◽  
Feifei Su
Keyword(s):  
Candida Albicans ◽  
Crystal Violet ◽  
Biofilm Formation ◽  
Quantitative Methods ◽  
Standard Procedure ◽  
Short Term ◽  
Biofilm Growth ◽  
Human Fungal Pathogen ◽  
Crystal Violet Assay ◽  
Reduction Assay

Abstract Background: The ability of the human fungal pathogen Candida albicans to form biofilms, for example on indwelling medical devices, is a major pathogenic mechanism and has been the focus of intense studies in the fungal pathogenesis field. A key research tool used is the quantitative methods for measuring biofilm formation of C. albicans. Objective: We sought to optimize the conventional crystal violet (CV) staining assay for quantification of biofilm formation by C. albicans and evaluate its performance. Methods: Individual modifications included (i) submerge-washing of microplates to remove non-adherent cells, (ii) heat-fixation, (iii) short-term staining for 3 min, (iv) submerge-washing to remove unbound CV dye, and (v) short-term destaining for 15 min were compared with the standard procedure, and those were superior were incorporated. Performance analysis was carried out for the modified CV assay, in comparison to the conventional CV assay and the XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide] reduction assay. Results: The modified CV assay demonstrated several advantages in quantitative assessment of biofilm formation of C. albicans over the conventional CV assay, including greater accuracy and reproducibility, shorter experimental time and reduced labor intensity, and was at least comparable to the XTT reduction assay.Conclusion: The modified CV method can be used as an alternative to the XTT reduction assay in quantification of biofilm growth by C. albicans.

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