Candida glabrataHas No Enhancing Role in the Pathogenesis ofCandida-Associated Denture Stomatitis in a Rat Model

ABSTRACTDenture stomatitis (DS) is a condition characterized by inflammation of the oral mucosa in direct contact with dentures and affects a significant number of otherwise healthy denture wearers.Candida-associated DS is predominantly caused byCandida albicans, a dimorphic fungus that readily colonizes and forms biofilms on denture materials. Previous studies showed a requirement forCandidabiofilm formation on both palate and dentures in infection and identified fungal morphogenic transcription factors, Efg1 and Bcr1, as key players in DS pathogenesis. While bothC. albicansandCandida glabrataare frequently coisolated in mucosal candidiasis, a pathogenic role forC. glabratain DS remains unknown. Using an established rat model of DS, we sought to determine whetherC. glabrataalone or coinoculation withC. albicansestablishes colonization and causes palatal tissue damage and inflammation. Rats fitted with custom dentures were inoculated withC. albicansand/orC. glabrataand monitored over a 4-week period for fungal burden (denture/palate), changes in body weight, and tissue damage via lactate dehydrogenase (LDH) release as well as palatal staining by hematoxylin and eosin (H&E) and immunohistochemistry for myeloperoxidase (MPO) as measures of inflammation.C. glabratacolonized the denture/palate similarly toC. albicans. In contrast toC. albicans, colonization byC. glabrataresulted in minimal changes in body weight, palatal LDH release, and MPO expression. Coinoculation with both species had no obvious modulation ofC. albicans-mediated pathogenic effects. These data suggest thatC. glabratareadily establishes colonization on denture and palate but has no apparent role for inducing/enhancingC. albicanspathogenesis in DS.IMPORTANCEMany denture wearers suffer fromCandida-associated denture stomatitis (DS), a fungal infection of the hard palate in contact with dentures. Biofilm formation byCandida albicanson denture/palate surfaces is considered a central process in the infection onset. AlthoughCandida glabratais frequently coisolated withC. albicans, its role in DS pathogenesis is unknown. We show here, using a contemporary rat model that employed a patented intraoral denture system, thatC. glabrataestablished stable colonization on the denture/palate. However, in contrast toC. albicansinoculated rats, rats inoculated withC. glabrataexhibited minimal changes in weight gain or palatal tissue damage. Likewise, coinoculation with the twoCandidaspecies resulted in no exacerbation ofC. albicans-induced DS pathology. Together, our findings indicate thatC. glabratahas no inducing/enhancing role in DS pathogenesis.

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Relative Abundances ofCandida albicansandCandida glabratainIn VitroCoculture Biofilms Impact Biofilm Structure and Formation

Applied and Environmental Microbiology ◽

10.1128/aem.02769-17 ◽

2018 ◽

Vol 84 (8) ◽

pp. e02769-17 ◽

Cited By ~ 9

Author(s):

Michelle L. Olson ◽

Arul Jayaraman ◽

Katy C. Kao

Keyword(s):

Gene Expression ◽

Candida Albicans ◽

Biofilm Formation ◽

Candida Glabrata ◽

Interspecific Interactions ◽

Host Immune System ◽

Dependent Manner ◽

Important Species ◽

Content Type ◽

Content Ratio

ABSTRACTCandidais a member of the normal human microbiota and often resides on mucosal surfaces such as the oral cavity or the gastrointestinal tract. In addition to their commensality,Candidaspecies can opportunistically become pathogenic if the host microbiota is disrupted or if the host immune system becomes compromised. An important factor forCandidapathogenesis is its ability to form biofilm communities. The two most medically important species—Candida albicansandCandida glabrata—are often coisolated from infection sites, suggesting the importance ofCandidacoculture biofilms. In this work, we report that biofilm formation of the coculture population depends on the relative ratio of starting cell concentrations ofC. albicansandC. glabrata. When using a starting ratio ofC. albicanstoC. glabrataof 1:3, ∼6.5- and ∼2.5-fold increases in biofilm biomass were observed relative to those of aC. albicansmonoculture and aC. albicans/C. glabrataratio of 1:1, respectively. Confocal microscopy analysis revealed the heterogeneity and complex structures composed of longC. albicanshyphae andC. glabratacell clusters in the coculture biofilms, and reverse transcription-quantitative PCR (qRT-PCR) studies showed increases in the relative expression of theHWP1andALS3adhesion genes in theC. albicans/C. glabrata1:3 biofilm compared to that in theC. albicansmonoculture biofilm. Additionally, only the 1:3C. albicans/C. glabratabiofilm demonstrated an increased resistance to the antifungal drug caspofungin. Overall, the results suggest that interspecific interactions between these two fungal pathogens increase biofilm formation and virulence-related gene expression in a coculture composition-dependent manner.IMPORTANCECandida albicansandCandida glabrataare often coisolated during infection, and the occurrence of coisolation increases with increasing inflammation, suggesting possible synergistic interactions between the twoCandidaspecies in pathogenesis. During the course of an infection, the prevalence of eachCandidaspecies may change over time due to differences in metabolism and in the resistance of each species to antifungal therapies. Therefore, it is necessary to understand the dynamics betweenC. albicansandC. glabratain coculture to develop better therapeutic strategies againstCandidainfections. Existingin vitrowork has focused on understanding how an equal-part culture ofC. albicansandC. glabrataimpacts biofilm formation and pathogenesis. What is not understood, and what is investigated in this work, is how the composition ofCandidaspecies in coculture impacts overall biofilm formation, virulence gene expression, and the therapeutic treatment of biofilms.

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Activities of Systemically Administered Echinocandins againstIn VivoMature Candida albicans Biofilms Developed in a Rat Subcutaneous Model

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02288-12 ◽

2013 ◽

Vol 57 (5) ◽

pp. 2365-2368 ◽

Cited By ~ 31

Author(s):

Soňa Kucharíková ◽

Nidhi Sharma ◽

Isabel Spriet ◽

Johan Maertens ◽

Patrick Van Dijck ◽

...

Keyword(s):

Body Weight ◽

Candida Albicans ◽

Rat Model ◽

Model System ◽

Content Type ◽

Cell Numbers ◽

Candida Albicans Biofilms

ABSTRACTThis study addresses the effects of micafungin, caspofungin, and anidulafungin againstCandida albicansbiofilms developed in a subcutaneous catheter rat model system. Doses of 5, 10, and 30 mg/kg (of body weight)/day (the last only for micafungin) were given intravenously for 5, 7, and 10 days. All three echinocandins caused a significant reduction of theCandidacell numbers on the implanted catheters and are thus promising for the treatment of biofilm-related infections.

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Development of a Contemporary Animal Model of Candida albicans-Associated Denture Stomatitis Using a Novel Intraoral Denture System

Infection and Immunity ◽

10.1128/iai.00019-12 ◽

2012 ◽

Vol 80 (5) ◽

pp. 1736-1743 ◽

Cited By ~ 45

Author(s):

Clorinda C. Johnson ◽

Alika Yu ◽

Heeje Lee ◽

Paul L. Fidel ◽

Mairi C. Noverr

Keyword(s):

Animal Model ◽

Candida Albicans ◽

Biofilm Formation ◽

Time Course ◽

Clinical Signs ◽

Clinical Score ◽

Content Type ◽

Denture Stomatitis ◽

Relevant Animal Model ◽

Repeated Sampling

ABSTRACTDenture stomatitis (DS) is a fungal infection characterized by inflammation of the oral mucosa in direct contact with the denture and affects up to 50% of denture wearers. Despite the prevalence, very little is known about the role of fungal or host factors that contribute to pathogenesis. Recently, we developed a novel intraoral denture system for rodent research. This denture system consists of custom-fitted fixed and removable parts to allow repeated sampling and longitudinal studies. The purpose of this study was to use this denture system to develop a clinically relevant animal model of DS. To establish DS, rats were inoculated with pelletedCandida albicans, which resulted in sustained colonization of the denture and palate for 8 weeks postinoculation. Biofilm formation on the denture was observed by week 4 and on the palate by week 6 postinoculation. Rats were monitored for clinical signs of disease by assigning a clinical score after macroscopic examination of the palate tissue according to Newton's method. By week 4 postinoculation, the majority of inoculated rats with dentures exhibited a clinical score of 1 (pinpoint erythema). By week 6 and week 8 postinoculation, increasing percentages of rats exhibited a clinical score of 2 (diffuse erythema/edema). Histological analysis of palate tissue demonstrated progressively increasing inflammatory cell recruitment throughout the time course of the infection. Palatal biofilm formation was commensurate with development of palatal erythema, which suggests a role for biofilm in the inflammatory response.

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In VitroAnalyses of the Effects of Heparin and Parabens on Candida albicans Biofilms and Planktonic Cells

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05061-11 ◽

2011 ◽

Vol 56 (1) ◽

pp. 148-153 ◽

Cited By ~ 15

Author(s):

Marisa H. Miceli ◽

Stella M. Bernardo ◽

T. S. Neil Ku ◽

Carla Walraven ◽

Samuel A. Lee

Keyword(s):

Candida Albicans ◽

Metabolic Activity ◽

Biofilm Formation ◽

High Dose ◽

Dependent Manner ◽

Planktonic Cells ◽

Content Type ◽

Heparin Sodium ◽

The Individual

ABSTRACTInfections and thromboses are the most common complications associated with central venous catheters. Suggested strategies for prevention and management of these complications include the use of heparin-coated catheters, heparin locks, and antimicrobial lock therapy. However, the effects of heparin onCandida albicansbiofilms and planktonic cells have not been previously studied. Therefore, we sought to determine thein vitroeffect of a heparin sodium preparation (HP) on biofilms and planktonic cells ofC. albicans. Because HP contains two preservatives, methyl paraben (MP) and propyl paraben (PP), these compounds and heparin sodium without preservatives (Pure-H) were also tested individually. The metabolic activity of the mature biofilm after treatment was assessed using XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and microscopy. Pure-H, MP, and PP caused up to 75, 85, and 60% reductions of metabolic activity of the mature preformedC. albicansbiofilms, respectively. Maximal efficacy against the mature biofilm was observed with HP (up to 90%) compared to the individual compounds (P< 0.0001). Pure-H, MP, and PP each inhibitedC. albicansbiofilm formation up to 90%. A complete inhibition of biofilm formation was observed with HP at 5,000 U/ml and higher. When tested against planktonic cells, each compound inhibited growth in a dose-dependent manner. These data indicated that HP, MP, PP, and Pure-H havein vitroantifungal activity againstC. albicansmature biofilms, formation of biofilms, and planktonic cells. Investigation of high-dose heparin-based strategies (e.g., heparin locks) in combination with traditional antifungal agents for the treatment and/or prevention ofC. albicansbiofilms is warranted.

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The Novel Arylamidine T-2307 MaintainsIn VitroandIn VivoActivity against Echinocandin-Resistant Candida albicans

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04228-14 ◽

2014 ◽

Vol 59 (2) ◽

pp. 1341-1343 ◽

Cited By ~ 14

Author(s):

Nathan P. Wiederhold ◽

Laura K. Najvar ◽

Annette W. Fothergill ◽

Rosie Bocanegra ◽

Marcos Olivo ◽

...

Keyword(s):

Body Weight ◽

Candida Albicans ◽

Invasive Candidiasis ◽

Placebo Control ◽

The Novel ◽

Content Type ◽

Fungal Burden ◽

Potential Use

ABSTRACTWe evaluated thein vitroandin vivoactivities of the investigational arylamidine T-2307 against echinocandin-resistantCandida albicans. T-2307 demonstrated potentin vitroactivity, and daily subcutaneous doses between 0.75 and 6 mg/kg of body weight significantly improved survival and reduced fungal burden compared to placebo control and caspofungin (10 mg/kg/day) in mice with invasive candidiasis caused by an echinocandin-resistant strain. Thus, T-2307 may have potential use in the treatment of echinocandin-resistantC. albicansinfections.

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Synergistic Interaction between Candida albicans and Commensal Oral Streptococci in a NovelIn VitroMucosal Model

Infection and Immunity ◽

10.1128/iai.05896-11 ◽

2011 ◽

Vol 80 (2) ◽

pp. 620-632 ◽

Cited By ~ 118

Author(s):

Patricia I. Diaz ◽

Zhihong Xie ◽

Takanori Sobue ◽

Angela Thompson ◽

Basak Biyikoglu ◽

...

Keyword(s):

Candida Albicans ◽

Gastrointestinal Tract ◽

Oral Mucosa ◽

Biofilm Formation ◽

Salivary Flow ◽

Flow Cell ◽

Synergistic Interaction ◽

Esophageal Mucosa ◽

Oral Streptococci ◽

Content Type

ABSTRACTCandida albicansis a commensal colonizer of the gastrointestinal tract of humans, where it coexists with highly diverse bacterial communities. It is not clear whether this interaction limits or promotes the potential ofC. albicansto become an opportunistic pathogen. Here we investigate the interaction betweenC. albicansand three species of streptococci from the viridans group, which are ubiquitous and abundant oral commensal bacteria. The ability ofC. albicansto form biofilms withStreptococcus oralis,Streptococcus sanguinis, orStreptococcus gordoniiwas investigated using flow cell devices that allow abiotic biofilm formation under salivary flow. In addition, we designed a novel flow cell system that allows mucosal biofilm formation under conditions that mimic the environment in the oral and esophageal mucosae. It was observed thatC. albicansand streptococci formed a synergistic partnership whereC. albicanspromoted the ability of streptococci to form biofilms on abiotic surfaces or on the surface of an oral mucosa analogue. The increased ability of streptococci to form biofilms in the presence ofC. albicanscould not be explained by a growth-stimulatory effect since the streptococci were unaffected in their growth in planktonic coculture withC. albicans. Conversely, the presence of streptococci increased the ability ofC. albicansto invade organotypic models of the oral and esophageal mucosae under conditions of salivary flow. Moreover, characterization of mucosal invasion by the biofilm microorganisms suggested that the esophageal mucosa is more permissive to invasion than the oral mucosa. In summary,C. albicansand commensal oral streptococci display a synergistic interaction with implications for the pathogenic potential ofC. albicansin the upper gastrointestinal tract.

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Denture Stomatitis: Report of a Case with Rarely Used Treatment Modality and Review of Literature

International Healthcare Research Journal ◽

10.26440/ihrj/0405.08029 ◽

2020 ◽

Vol 4 (5) ◽

pp. 116-119

Author(s):

Parul Uppal Malhotra ◽

Neera Ohri ◽

Yagyeshwar Malhotra ◽

Anindita Mallik

Keyword(s):

Candida Albicans ◽

Candida Species ◽

Fungal Infections ◽

Bacterial Colonization ◽

Oral Candidiasis ◽

Clinical Signs ◽

Fungal Growth ◽

Dimorphic Fungus ◽

Denture Stomatitis ◽

Microbial Invasion

Candida albicans is the most common Candida species isolated from the oral cavity both in healthy and diseased. Candida albicans is a dimorphic fungus existing both in blastopore phase (yeast phase) and the hyphal or mycelial phase. Although these organisms typically colonize mucocutaneous surfaces, the latter can be portals of entry into deeper tissues when host defences are compromised. Denture stomatitis is a common form of oral candidiasis that manifests as a diffuse inflammation of the maxillary denture bearing areas & is associated with angular cheilitis. At least 70% of individuals with clinical signs of denture stomatitis exhibit fungal growth & these conditions most likely result from yeast colonization of the oral mucosa combined with Bacterial colonization. Candida species act as an endogenous infecting agent on tissue predisposed by chronic trauma to microbial invasion. At one time, oral fungal infections were rare findings in general dentist's office. They were more commonly seen in hospitalized and severely debilitated patients. However with enhanced medical and pharmaceutical technology, increasing numbers of ambulatory immunosuppressed individuals with oral fungal infections are seeking out general dentists for diagnosis and treatment of these lesions.

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Probiotic Yeasts Inhibit Virulence of Non-albicans Candida Species

mBio ◽

10.1128/mbio.02307-19 ◽

2019 ◽

Vol 10 (5) ◽

Cited By ~ 5

Author(s):

Lohith Kunyeit ◽

Nawneet K. Kurrey ◽

K. A. Anu-Appaiah ◽

Reeta P. Rao

Keyword(s):

Saccharomyces Cerevisiae ◽

Candida Tropicalis ◽

Biofilm Formation ◽

Candida Glabrata ◽

Candida Parapsilosis ◽

Candida Krusei ◽

Probiotic Properties ◽

Candida Auris ◽

Content Type ◽

Alternative Approach

ABSTRACT Systemic infections of Candida species pose a significant threat to public health. Toxicity associated with current therapies and emergence of resistant strains present major therapeutic challenges. Here, we report exploitation of the probiotic properties of two novel, food-derived yeasts, Saccharomyces cerevisiae (strain KTP) and Issatchenkia occidentalis (strain ApC), as an alternative approach to combat widespread opportunistic fungal infections. Both yeasts inhibit virulence traits such as adhesion, filamentation, and biofilm formation of several non-albicans Candida species, including Candida tropicalis, Candida krusei, Candida glabrata, and Candida parapsilosis as well as the recently identified multidrug-resistant species Candida auris. They inhibit adhesion to abiotic surfaces as well as cultured colon epithelial cells. Furthermore, probiotic treatment blocks the formation of biofilms of individual non-albicans Candida strains as well as mixed-culture biofilms of each non-albicans Candida strain in combination with Candida albicans. The probiotic yeasts attenuated non-albicans Candida infections in a live animal. In vivo studies using Caenorhabditis elegans suggest that exposure to probiotic yeasts protects nematodes from infection with non-albicans Candida strains compared to worms that were not exposed to the probiotic yeasts. Furthermore, application of probiotic yeasts postinfection with non-albicans Candida alleviated pathogenic colonization of the nematode gut. The probiotic properties of these novel yeasts are better than or comparable to those of the commercially available probiotic yeast Saccharomyces boulardii, which was used as a reference strain throughout this study. These results indicate that yeasts derived from food sources could serve as an effective alternative to antifungal therapy against emerging pathogenic Candida species. IMPORTANCE Non-albicans Candida-associated infections have emerged as a major risk factor in the hospitalized and immunecompromised patients. Besides, antifungal-associated complications occur more frequently with these non-albicans Candida species than with C. albicans. Therefore, as an alternative approach to combat these widespread non-albicans Candida-associated infections, here we showed the probiotic effect of two yeasts, Saccharomyces cerevisiae (strain KTP) and Issatchenkia occidentalis (ApC), in preventing adhesion and biofilm formation of five non-albicans Candida strains, Candida tropicalis, Candida krusei, Candida glabrata, Candida parapsilosis, and Candida auris. The result would influence the current trend of the conversion of conventional antimicrobial therapy into beneficial probiotic microbe-associated antimicrobial treatment.

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Hormones modulate Candida vaginal isolates biofilm formation and decrease their susceptibility to azoles and hydrogen peroxide

Medical Mycology ◽

10.1093/mmy/myz070 ◽

2019 ◽

Vol 58 (3) ◽

pp. 341-350

Author(s):

Bruna Gonçalves ◽

Nuno Miguel Azevedo ◽

Mariana Henriques ◽

Sónia Silva

Keyword(s):

Hydrogen Peroxide ◽

Candida Albicans ◽

Biofilm Formation ◽

Candida Glabrata ◽

The Other ◽

Environmental Cues ◽

Intrauterine Devices ◽

Normal Cycle ◽

Acidic Conditions ◽

High Adaptation

Abstract Vulvovaginal candidiasis (VVC) is an infection usually caused by Candida albicans and increasingly by Candida glabrata, which has an intrinsically high resistance to commonly used antifungals. Candida species possess virulence factors that contribute to VVC development, as the ability to form biofilms in vaginal walls and intrauterine devices. It is known that VVC is promoted by conditions that increase the hormones levels, during pregnancy, however, the effects of hormones on Candida cells are poorly studied, especially in C. glabrata. Thus, the influence of progesterone and β-estradiol, at normal cycle and pregnancy concentrations, on biofilm formation and resistance of C. albicans and C. glabrata vaginal isolates, was analyzed using acidic conditions (pH 4). Biofilms of C. albicans developed in the presence of hormones presented reduced biomass (up to 65%) and impaired cells ability to produce filamentous forms. On the other hand, C. glabrata presented high adaptation to the presence of hormones, which did not affect its biofilm formation. Additionally, hormones impaired the susceptibility of C. albicans and C. glabrata cells to azoles, with potential clinical significance in the presence of pregnancy hormone levels. A similar result was obtained for the susceptibility to hydrogen peroxide, a biological vaginal barrier against Candida growth. Overall, the results of this study suggest that hormones may act as environmental cues promoting Candida protection from vaginal defenses and harmful conditions, what may have implications in Candida vaginal pathogenicity and treatment of VVC, especially in C. glabrata infections due to its high adaptability to vaginal conditions.

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An Amyloid Core Sequence in the Major Candida albicans Adhesin Als1p Mediates Cell-Cell Adhesion

mBio ◽

10.1128/mbio.01766-19 ◽

2019 ◽

Vol 10 (5) ◽

Author(s):

Vida Ho ◽

Philippe Herman-Bausier ◽

Christopher Shaw ◽

Karen A. Conrad ◽

Melissa C. Garcia-Sherman ◽

...

Keyword(s):

Candida Albicans ◽

Cell Adhesion ◽

Cell Surface ◽

Biofilm Formation ◽

Force Spectroscopy ◽

Cell Aggregation ◽

Analysis Tool ◽

Content Type ◽

Core Sequence ◽

Cell Cell

ABSTRACT The human fungal commensal Candida albicans can become a serious opportunistic pathogen in immunocompromised hosts. The C. albicans cell adhesion protein Als1p is a highly expressed member of a large family of paralogous adhesins. Als1p can mediate binding to epithelial and endothelial cells, is upregulated in infections, and is important for biofilm formation. Als1p includes an amyloid-forming sequence at amino acids 325 to 331, identical to the sequence in the paralogs Als5p and Als3p. Therefore, we mutated Val326 to test whether this sequence is important for activity. Wild-type Als1p (Als1pWT) and Als1p with the V326N mutation (Als1pV326N) were expressed at similar levels in a Saccharomyces cerevisiae surface display model. Als1pV326N cells adhered to bovine serum albumin (BSA)-coated beads similarly to Als1pWT cells. However, cells displaying Als1pV326N showed visibly smaller aggregates and did not fluoresce in the presence of the amyloid-binding dye Thioflavin-T. A new analysis tool for single-molecule force spectroscopy-derived surface mapping showed that statistically significant force-dependent Als1p clustering occurred in Als1pWT cells but was absent in Als1pV326N cells. In single-cell force spectroscopy experiments, strong cell-cell adhesion was dependent on an intact amyloid core sequence on both interacting cells. Thus, the major adhesin Als1p interacts through amyloid-like β-aggregation to cluster adhesin molecules in cis on the cell surface as well as in trans to form cell-cell bonds. IMPORTANCE Microbial cell surface adhesins control essential processes such as adhesion, colonization, and biofilm formation. In the opportunistic fungal pathogen Candida albicans, the agglutinin-like sequence (ALS) gene family encodes eight cell surface glycoproteins that mediate adherence to biotic and abiotic surfaces and cell-cell aggregation. Als proteins are critical for commensalism and virulence. Their activities include attachment and invasion of endothelial and epithelial cells, morphogenesis, and formation of biofilms on host tissue and indwelling medical catheters. At the molecular level, Als5p-mediated cell-cell aggregation is dependent on the formation of amyloid-like nanodomains between Als5p-expressing cells. A single-site mutation to valine 326 abolishes cellular aggregation and amyloid formation. Our results show that the binding characteristics of Als1p follow a mechanistic model similar to Als5p, despite its differential expression and biological roles.

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