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Sample records for candida albicans growth

  1. Gymnemic Acids Inhibit Hyphal Growth and Virulence in Candida albicans

    PubMed Central

    Vediyappan, Govindsamy; Dumontet, Vincent; Pelissier, Franck; d’Enfert, Christophe

    2013-01-01

    Candida albicans is an opportunistic and polymorphic fungal pathogen that causes mucosal, disseminated and invasive infections in humans. Transition from the yeast form to the hyphal form is one of the key virulence factors in C. albicans contributing to macrophage evasion, tissue invasion and biofilm formation. Nontoxic small molecules that inhibit C. albicans yeast-to-hypha conversion and hyphal growth could represent a valuable source for understanding pathogenic fungal morphogenesis, identifying drug targets and serving as templates for the development of novel antifungal agents. Here, we have identified the triterpenoid saponin family of gymnemic acids (GAs) as inhibitor of C. albicans morphogenesis. GAs were isolated and purified from Gymnema sylvestre leaves, the Ayurvedic traditional medicinal plant used to treat diabetes. Purified GAs had no effect on the growth and viability of C. albicans yeast cells but inhibited its yeast-to-hypha conversion under several hypha-inducing conditions, including the presence of serum. Moreover, GAs promoted the conversion of C. albicans hyphae into yeast cells under hypha inducing conditions. They also inhibited conidial germination and hyphal growth of Aspergillus sp. Finally, GAs inhibited the formation of invasive hyphae from C. albicans-infected Caenorhabditis elegans worms and rescued them from killing by C. albicans. Hence, GAs could be useful for various antifungal applications due to their traditional use in herbal medicine. PMID:24040201

  2. Gymnemic acids inhibit hyphal growth and virulence in Candida albicans.

    PubMed

    Vediyappan, Govindsamy; Dumontet, Vincent; Pelissier, Franck; d'Enfert, Christophe

    2013-01-01

    Candida albicans is an opportunistic and polymorphic fungal pathogen that causes mucosal, disseminated and invasive infections in humans. Transition from the yeast form to the hyphal form is one of the key virulence factors in C. albicans contributing to macrophage evasion, tissue invasion and biofilm formation. Nontoxic small molecules that inhibit C. albicans yeast-to-hypha conversion and hyphal growth could represent a valuable source for understanding pathogenic fungal morphogenesis, identifying drug targets and serving as templates for the development of novel antifungal agents. Here, we have identified the triterpenoid saponin family of gymnemic acids (GAs) as inhibitor of C. albicans morphogenesis. GAs were isolated and purified from Gymnema sylvestre leaves, the Ayurvedic traditional medicinal plant used to treat diabetes. Purified GAs had no effect on the growth and viability of C. albicans yeast cells but inhibited its yeast-to-hypha conversion under several hypha-inducing conditions, including the presence of serum. Moreover, GAs promoted the conversion of C. albicans hyphae into yeast cells under hypha inducing conditions. They also inhibited conidial germination and hyphal growth of Aspergillus sp. Finally, GAs inhibited the formation of invasive hyphae from C. albicans-infected Caenorhabditis elegans worms and rescued them from killing by C. albicans. Hence, GAs could be useful for various antifungal applications due to their traditional use in herbal medicine.

  3. Effects of ambroxol on Candida albicans growth and biofilm formation.

    PubMed

    Rene, Hernandez-Delgadillo; José, Martínez-Sanmiguel Juan; Isela, Sánchez-Nájera Rosa; Claudio, Cabral-Romero

    2014-04-01

    Typically, the onset of candidiasis is characterised by the appearance of a biofilm of Candida albicans, which is associated with several diseases including oral candidiasis in young and elderly people. The objective of this work was to investigate the in vitro fungicidal activity as well as the antibiofilm activity of ambroxol (AMB) against C. albicans growth. In the present investigation, the fungicidal activity of AMB was established using the cell viability 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Also the minimum inhibitory concentration (MIC) of AMB required to inhibit the fungal growth was determined. Simultaneously, the antibiofilm activity of AMB was evaluated using fluorescence microscopy. The study revealed that 2 mg ml(-1) of AMB exhibited higher fungicidal activity than 3.3 mg ml(-1) of terbinafine, one of most common commercial antifungals. A MIC of 1 mg ml(-1) was determined for AMB to interfere with C. albicans growth. Furthermore, AMB was found to be effective in inhibiting the biofilm formation of C. albicans and exerted its fungicidal activity against the fungal cells interspersed in the preformed biofilm. The study suggests a potential role of the mucolytic agent, AMB, as an interesting therapeutic alternative in the treatment of oral candidiasis. © 2013 Blackwell Verlag GmbH.

  4. Culture media profoundly affect Candida albicans and Candida tropicalis growth, adhesion and biofilm development

    PubMed Central

    Weerasekera, Manjula M; Wijesinghe, Gayan K; Jayarathna, Thilini A; Gunasekara, Chinthika P; Fernando, Neluka; Kottegoda, Nilwala; Samaranayake, Lakshman P

    2016-01-01

    As there are sparse data on the impact of growth media on the phenomenon of biofilm development for Candida we evaluated the efficacy of three culture media on growth, adhesion and biofilm formation of two pathogenic yeasts, Candida albicans and Candida tropicalis. The planktonic phase yeast growth, either as monocultures or mixed cultures, in sabouraud dextrose broth (SDB), yeast nitrogen base (YNB), and RPMI 1640 was compared, and adhesion as well as biofilm formation were monitored using MTT and crystal violet (CV) assays and scanning electron microscopy. Planktonic cells of C. albicans, C. tropicalis and their 1:1 co-culture showed maximal growth in SDB. C. albicans/C. tropicalis adhesion was significantly facilitated in RPMI 1640 although the YNB elicited the maximum growth for C. tropicalis. Similarly, the biofilm growth was uniformly higher for both species in RPMI 1640, and C. tropicalis was the slower biofilm former in all three media. Scanning electron microscopy images tended to confirm the results of MTT and CV assay. Taken together, our data indicate that researchers should pay heed to the choice of laboratory culture media when comparing relative planktonic/biofilm growth of Candida. There is also a need for standardisation of biofilm development media so as to facilitate cross comparisons between laboratories. PMID:27706381

  5. Potential of plant oils as inhibitors of Candida albicans growth.

    PubMed

    Devkatte, Anupama N; Zore, Gajanan B; Karuppayil, S Mohan

    2005-06-01

    Minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) were determined for 38 oils of plant origin against Candida albicans. Four strains including one standard strain were used in this study. The antifungal agents, Fluconazole and Amphotericin B were used as positive controls. The standard strain (ATCC10231) used in this study was found to be highly resistant to Fluconazole: 3000 microg ml(-1) of Fluconazole was required to inhibit the growth of this strain partially, and complete inhibition could not be achieved. Other Candida strains were sensitive to 5 microg ml(-1) of Fluconazole. All the strains used were sensitive to Amphotericin B. Of the 38 oils tested, 23 were found effective and fifteen were ineffective. Based on their MFCs, effective oils were categorized into three categories. Seven oils, which exerted fungicidal effect at less than 0.15% concentration of oils, were grouped into the most effective class. The oils exhibiting MFCs in the range of 0.16-1.5% concentration were considered moderately effective. Nine oils, which required more than 1.5% concentration, were regarded as less effective. The Fluconazole-resistant strain (MTCC 227) was sensitive to at least 23 of the plant oils. Results of this study indicate that oils of plant origin may find use as potential anti-Candida agents.

  6. Nisin Z inhibits the growth of Candida albicans and its transition from blastospore to hyphal form.

    PubMed

    Le Lay, C; Akerey, B; Fliss, I; Subirade, M; Rouabhia, M

    2008-11-01

    To investigate the efficacy of nisin Z, an antimicrobial peptide produced by certain strains of Lactococcus lactis against Candida albicans growth and transition. Candida albicans was cultured in the presence of various concentrations of nisin Z (1000, 500, and 100 microg ml(-1)) for different time points. Candida albicans growth was determined using the Alamar Blue assay. The yeast's transition from blastospore to hyphal form was assessed through optical microscope observations. The effect of nisin Z on C. albicans ultrastructure was followed by scanning and transmission electron microscopy. Our results show that nisin Z inhibited C. albicans growth beginning at 500 microg ml(-1). This inhibition was both time- and dose-dependent. Nisin Z was also active against C. albicans transition by significantly inhibiting the transformation of C. albicans from the blastospore to hyphal form. Treatments with nisin Z lead to ultrastructural disturbances of C. albicans. Our findings indicate that nisin Z significantly reduced C. albicans growth and transition. These effects may have occurred through ultrastructural modifications of this yeast. For the first time, effect of nisin Z on C. albicans was investigated. These results therefore suggest that nisin Z may have antifungal properties, and could be used as an antifungal molecule.

  7. Candida albicans survival, growth and biofilm formation are differently affected by mouthwashes: an in vitro study.

    PubMed

    Paulone, Simona; Malavasi, Giulia; Ardizzoni, Andrea; Orsi, Carlotta Francesca; Peppoloni, Samuele; Neglia, Rachele Giovanna; Blasi, Elisabetta

    2017-01-01

    Candida albicans is the most common cause of oral mycoses. The aim of the present study was to investigate in vitro the susceptibility of C. albicans to mouthwashes, in terms of growth, survival and biofilm formation. Candida albicans, laboratory strain SC5314, and 7 commercial mouthwashes were employed: 3 with 0.2% chlorhexidine digluconate; 1 with 0.06% chlorhexidine digluconate and 250 ppm F- sodium fluoride; 3 with fluorine-containing molecules. None of the mouthwashes contained ethanol in their formulations. The anti-Candida effects of the mouthwashes were assessed by disk diffusion, crystal violet and XTT assays. By using five protocols combining different dilutions and contact times the mouthwashes were tested against: 1) C. albicans growth; 2) biofilm formation; 3) survival of fungal cells in early, developing and mature Candida biofilm. Chlorhexidine digluconate-containing mouthwashes consistently exhibited the highest anti-Candida activity, irrespective of the protocols employed. Fungal growth, biofilm formation and survival of Candida cells within biofilm were impaired, the effects strictly depending on both the dilution employed and the time of contact. These in vitro studies provide evidence that mouthwashes exert anti-Candida activity against both planktonic and biofilm fungal structures, but to a different extent depending on their composition. This suggests special caution in the choice of mouthwashes for oral hygiene, whether aimed at prevention or treatment of oral candidiasis.

  8. The effect of denture adhesives on Candida albicans growth in vitro.

    PubMed

    Sampaio-Maia, Benedita; Figueiral, Maria Helena; Sousa-Rodrigues, Patricia; Fernandes, Maria Helena; Scully, Crispian

    2012-06-01

    Denture-wearing favours the growth of Candida. In view of the fact that many denture wearers regularly use adhesives to enhance denture retention, stability and function, the aim of this work was to study the effect of denture adhesives on Candida albicans growth in vitro. The denture adhesives tested were Corega(®) cream, Kukident(®) cream, Novafix(®) cream, Polident(®) cream, Protefix(®) cream, Steradent(®) cream, Aderyn(®) powder, Corega(®) ultra powder, Protefix(®) powder and Corega(®) strip. C. albicans growth curves were obtained in the presence or absence of a 1% solution of the denture adhesive diluted in Sabouraud broth. Macro- and microscopic morphological changes in C. albicans were analysed, as was microbial contamination of the denture adhesive. Most of the denture adhesives studied induced morphological changes in C. albicans cells and colonies, but only two had any significant inhibitory effect on yeast growth. Kukident(®) cream markedly inhibited C. albicans growth in a concentration-dependent way, reducing the growth rate by 95%, whereas Corega(®) cream also inhibited C. albicans growth but in a non-concentration-dependent way, reducing the growth rate by 37%. In addition, denture adhesives available as powders had detectable microbial contamination. Some commercially available denture adhesives showed microbial contamination and some had significant inhibitory effect on C. albicans growth. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

  9. Effect of trace iron levels and iron withdrawal by chelation on the growth of Candida albicans and Candida vini.

    PubMed

    Holbein, Bruce E; Mira de Orduña, Ramón

    2010-06-01

    The iron requirements of the opportunistic pathogenic yeast, Candida albicans, and the related nonpathogenic spoilage yeast Candida vini were investigated along with their responses to various exogenous iron chelators. The influence of iron as well as the exogenous chelating agents lactoferrin, EDTA, deferiprone, desferrioxamine, bathophenanthroline sulphonate and a novel carried chelator with a hydroxypyridinone-like Fe-ligand functionality, DIBI, on fungal growth was studied in a chemically defined medium deferrated to trace iron levels (<1.2 microg L(-1) or 0.02 microM of Fe). Candida albicans competed better at low iron levels compared with C. vini, which was also more susceptible to most added chelators. Candida albicans was resistant to lactoferrin at physiologically relevant concentrations, but was inhibited by low concentrations of DIBI. Candida vini was sensitive to lactoferrin as well as to DIBI, whose inhibitory activity was shown to be Fe reversible. The pathogenic potential of C. albicans and the nonpathogenic nature of C. vini were consistent with their differing abilities to grow under iron-limiting conditions and in the presence of exogenous iron chelators. Both yeasts could be controlled by appropriately strong chelators. This work provides the first evidence of the iron requirements of the spoilage organism C. vini and its response to exogenous chelators. Efficient iron withdrawal has the potential to provide the basis for new fungal growth control strategies.

  10. Potential Targets for Antifungal Drug Discovery Based on Growth and Virulence in Candida albicans.

    PubMed

    Li, Xiuyun; Hou, Yinglong; Yue, Longtao; Liu, Shuyuan; Du, Juan; Sun, Shujuan

    2015-10-01

    Fungal infections, especially infections caused by Candida albicans, remain a challenging problem in clinical settings. Despite the development of more-effective antifungal drugs, their application is limited for various reasons. Thus, alternative treatments with drugs aimed at novel targets in C. albicans are needed. Knowledge of growth and virulence in fungal cells is essential not only to understand their pathogenic mechanisms but also to identify potential antifungal targets. This article reviews the current knowledge of the mechanisms of growth and virulence in C. albicans and examines potential targets for the development of new antifungal drugs.

  11. Growth of Candida albicans in human saliva is supported by low-molecular-mass compounds.

    PubMed

    Valentijn-Benz, Marianne; Nazmi, Kamran; Brand, Henk S; van't Hof, Wim; Veerman, Enno C I

    2015-12-01

    Saliva plays a key role in the maintenance of a stable oral microflora. It contains antimicrobial compounds but also functions as a substrate for growth of bacteria under conditions of low external nutrient supply. Besides bacteria, yeasts, in particular Candida albicans, commonly inhabit the oral cavity. Under immunocompromised conditions, instantaneous outgrowth of this yeast occurs in oral carriers of C. albicans, suggesting that this yeast is able to survive in the oral cavity with saliva as sole source of growth substrate. The aim of the present study was to identify the salivary constituents that are used by C. albicans for growth and survival in saliva. In addition, we have explored the effect of growth in saliva on the susceptibility of C. albicans to histatin 5, a salivary antifungal peptide. It was found that C. albicans was able to grow in human saliva without addition of glucose, and in the stationary phase could survive for more than 400 h. Candida albicans grown in saliva was more than 10 times less susceptible for salivary histatin 5 than C. albicans cultured in Sabouraud medium.

  12. The non-steroidal anti-inflammatory drug niflumic acid inhibits Candida albicans growth.

    PubMed

    Baker, Andrew; Northrop, Frederick D; Miedema, Hendrik; Devine, Gary R; Davies, Julia M

    2002-01-01

    The non-steroidal anti-inflammatory drug niflumic acid was found to inhibit growth of the yeast form of Candida albicans. Niflumic acid inhibited respiratory oxygen uptake and it is hypothesised that this was achieved by cytosolic acidification and block of glycolysis. Inhibitory concentrations are compatible with current practice of topical application.

  13. Terpenoids inhibit Candida albicans growth by affecting membrane integrity and arrest of cell cycle.

    PubMed

    Zore, Gajanan B; Thakre, Archana D; Jadhav, Sitaram; Karuppayil, S Mohan

    2011-10-15

    Anti-Candida potential of six terpenoids were evaluated in this study against various isolates of Candida albicans (n=39) and non-C. albicans (n=9) that are differentially susceptible to fluconazole. All the six terpenoids tested, showed excellent activity and were equally effective against isolates of Candida sps., tested in this study. Linalool and citral were the most effective ones, inhibiting all the isolates at ≤0.064% (v/v). Five among the six terpenoids tested were fungicidal. Time dependent kill curve assay showed that MFCs of linalool and eugenol were highly toxic to C. albicans, killing 99.9% inoculum within seven min of exposure, while that of citronellal, linalyl acetate and citral required 15min, 1h and 2h, respectively. FIC index values (Linalool - 0.140, benzyl benzoate - 0.156, eugenol - 0.265, citral - 0.281 and 0.312 for linalyl acetate and citronellal) and isobologram obtained by checker board assay showed that all the six terpenoids tested exhibit excellent synergistic activity with fluconazole against a fluconazole resistant strain of C. albicans. Terpenoids tested arrested C. albicans cells at different phases of the cell cycle i.e. linalool and LA at G1, citral and citronellal at S phase and benzyl benzoate at G2-M phase and induced apoptosis. Linalool, citral, citronellal and benzyl benzoate caused more than 50% inhibition of germ tube induction at 0.008%, while eugenol and LA required 0.032 and 0.016% (v/v) concentrations, respectively. MICs of all the terpenoids for the C. albicans growth were non toxic to HeLa cells. Terpenoids tested exhibited excellent activity against C. albicans yeast and hyphal form growth at the concentrations that are non toxic to HeLa cells. Terpenoids tested in this study may find use in antifungal chemotherapy, not only as antifungal agents but also as synergistic agents along with conventional drugs like fluconazole.

  14. The effect of cinnamaldehyde on the growth and the morphology of Candida albicans.

    PubMed

    Taguchi, Yuuki; Hasumi, Yayoi; Abe, Shigeru; Nishiyama, Yayoi

    2013-03-01

    We examined the viability and morphology of Candida albicans under experimental conditions after treatment with varying concentrations of cinnamaldehyde, the major component of cassia (Cinnamomum cassia), using XTT assay, fluorescent microscopy, scanning electron microscopy, and thin-section electron microscopy. At 10 μg/ml level, cinnamaldehyde inhibited mycelial growth, but did not affect the growth of yeast cells, metabolic activity, cell shape, or the ultrastructure of the cells. At 40 μg/ml level, cinnamaldehyde showed fungicidal activity accompanied by alteration of the membrane and interior of Candida cells. These findings indicate that cinnamaldehyde has both fungistatic and fungicidal activities against C. albicans and affects the structure of the cells.

  15. Adding Biotin to Parenteral Nutrition Solutions Without Lipid Accelerates the Growth of Candida albicans

    PubMed Central

    Kuwahara, Takashi; Kaneda, Shinya; Shimono, Kazuyuki

    2016-01-01

    Background: We have previously demonstrated that Candida albicans requires multivitamins (MVs) or lipid to increase rapidly in parenteral nutrition (PN) solutions. In this study, in detail, the effects of vitamins on the growth of C. albicans in PN solutions without lipid were investigated. Methods: In the 1st experiment, a commercial PN solution without lipid was supplemented with water-soluble vitamins (SVs: vitamins B1, B2, B6, B12 and C, folic acid, nicotinamide, biotin and panthenol), water-insoluble vitamins (IVs: vitamins A, D, E and K) or both (MVs). In the 2nd experiment, the test solutions were prepared by supplementing the PN solution with one of each or all of the SVs. In the 3rd experiment, another commercial peripheral PN (PPN) solution without lipid was supplemented with SVs, nicotinic acid, biotin or both nicotinic acid and biotin. In each of the experiments, a specified number of C. albicans organisms was added to each test solution, and all of the test solutions were allowed to stand at room temperature (23-26ºC). The number of C. albicans was counted at 0, 24, 48 and 72 hours after the addition of the organism. Results: In the 1st experiment, the C. albicans increased rapidly in the PN solution supplemented with the SVs, but increased slowly without the SVs, regardless of the addition of the IVs. In the 2nd experiment, the C. albicans increased rapidly in the PN solution supplemented with the SVs or biotin, but increased slowly with each of the other water-soluble vitamins. In the 3rd experiment, the C. albicans increased rapidly in the PPN solution supplemented with the SVs or biotin, but increased slowly with the addition of nicotinic acid. Conclusions: These results suggested that adding MVs or SVs to PN solutions without lipid promotes the growth of C. albicans, and that this effect is mostly attributable to biotin. PMID:27648003

  16. Adding Biotin to Parenteral Nutrition Solutions Without Lipid Accelerates the Growth of Candida albicans.

    PubMed

    Kuwahara, Takashi; Kaneda, Shinya; Shimono, Kazuyuki

    2016-01-01

    We have previously demonstrated that Candida albicans requires multivitamins (MVs) or lipid to increase rapidly in parenteral nutrition (PN) solutions. In this study, in detail, the effects of vitamins on the growth of C. albicans in PN solutions without lipid were investigated. In the 1st experiment, a commercial PN solution without lipid was supplemented with water-soluble vitamins (SVs: vitamins B1, B2, B6, B12 and C, folic acid, nicotinamide, biotin and panthenol), water-insoluble vitamins (IVs: vitamins A, D, E and K) or both (MVs). In the 2nd experiment, the test solutions were prepared by supplementing the PN solution with one of each or all of the SVs. In the 3rd experiment, another commercial peripheral PN (PPN) solution without lipid was supplemented with SVs, nicotinic acid, biotin or both nicotinic acid and biotin. In each of the experiments, a specified number of C. albicans organisms was added to each test solution, and all of the test solutions were allowed to stand at room temperature (23-26ºC). The number of C. albicans was counted at 0, 24, 48 and 72 hours after the addition of the organism. In the 1st experiment, the C. albicans increased rapidly in the PN solution supplemented with the SVs, but increased slowly without the SVs, regardless of the addition of the IVs. In the 2nd experiment, the C. albicans increased rapidly in the PN solution supplemented with the SVs or biotin, but increased slowly with each of the other water-soluble vitamins. In the 3rd experiment, the C. albicans increased rapidly in the PPN solution supplemented with the SVs or biotin, but increased slowly with the addition of nicotinic acid. These results suggested that adding MVs or SVs to PN solutions without lipid promotes the growth of C. albicans, and that this effect is mostly attributable to biotin.

  17. Flexible camphor diamond-like carbon coating on polyurethane to prevent Candida albicans biofilm growth.

    PubMed

    Santos, Thaisa B; Vieira, Angela A; Paula, Luciana O; Santos, Everton D; Radi, Polyana A; Khouri, Sônia; Maciel, Homero S; Pessoa, Rodrigo S; Vieira, Lucia

    2017-04-01

    Camphor was incorporated in diamond-like carbon (DLC) films to prevent the Candida albicans yeasts fouling on polyurethane substrates, which is a material commonly used for catheter manufacturing. The camphor:DLC and DLC film for this investigation was produced by plasma enhanced chemical vapor deposition (PECVD), using an apparatus based on the flash evaporation of organic liquid (hexane) containing diluted camphor for camphor:DLC and hexane/methane, mixture for DLC films. The film was deposited at a low temperature of less than 25°C. We obtained very adherent camphor:DLC and DLC films that accompanied the substrate flexibility without delamination. The adherence of camphor:DLC and DLC films on polyurethane segments were evaluated by scratching test and bending polyurethane segments at 180°. The polyurethane samples, with and without camphor:DLC and DLC films were characterized by Raman spectroscopy, scanning electron microscopy, atomic force microscopy, and optical profilometry. Candida albicans biofilm formation on polyurethane, with and without camphor:DLC and DLC, was assessed. The camphor:DLC and DLC films reduced the biofilm growth by 99.0% and 91.0% of Candida albicans, respectively, compared to bare polyurethane. These results open the doors to studies of functionalized DLC coatings with biofilm inhibition properties used in the production of catheters or other biomedical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. The GRF10 homeobox gene regulates filamentous growth in the human fungal pathogen Candida albicans.

    PubMed

    Ghosh, Anup K; Wangsanut, Tanaporn; Fonzi, William A; Rolfes, Ronda J

    2015-12-01

    Candida albicans is the most common human fungal pathogen and can cause life-threatening infections. Filamentous growth is critical in the pathogenicity of C. albicans, as the transition from yeast to hyphal forms is linked to virulence and is also a pivotal process in fungal biofilm development. Homeodomain-containing transcription factors have been linked to developmental processes in fungi and other eukaryotes. We report here on GRF10, a homeobox transcription factor-encoding gene that plays a role in C. albicans filamentation. Deletion of the GRF10 gene, in both C. albicans SN152 and BWP17 strain backgrounds, results in mutants with strongly decreased hyphal growth. The mutants are defective in chlamydospore and biofilm formation, as well as showing dramatically attenuated virulence in a mouse infection model. Expression of the GRF10 gene is highly induced during stationary phase and filamentation. In summary, our study emphasizes a new role for the homeodomain-containing transcription factor in morphogenesis and pathogenicity of C. albicans.

  19. Candida albicans pathogenicity mechanisms

    PubMed Central

    Mayer, François L.; Wilson, Duncan; Hube, Bernhard

    2013-01-01

    The polymorphic fungus Candida albicans is a member of the normal human microbiome. In most individuals, C. albicans resides as a lifelong, harmless commensal. Under certain circumstances, however, C. albicans can cause infections that range from superficial infections of the skin to life-threatening systemic infections. Several factors and activities have been identified which contribute to the pathogenic potential of this fungus. Among them are molecules which mediate adhesion to and invasion into host cells, the secretion of hydrolases, the yeast-to-hypha transition, contact sensing and thigmotropism, biofilm formation, phenotypic switching and a range of fitness attributes. Our understanding of when and how these mechanisms and factors contribute to infection has significantly increased during the last years. In addition, novel virulence mechanisms have recently been discovered. In this review we present an update on our current understanding of the pathogenicity mechanisms of this important human pathogen. PMID:23302789

  20. The mating projections of Saccharomyces cerevisiae and Candida albicans show key characteristics of hyphal growth.

    PubMed

    Chapa-Y-Lazo, Bernardo; Lee, Sheu; Regan, Hannah; Sudbery, Peter

    2011-06-01

    Fungi can grow in a variety of growth forms: yeast, pseudohyphae and hyphae. The human fungal pathogen Candida albicans can grow in all three of these forms. In this fungus, hyphal growth is distinguished by the presence of a Spitzenkörper-like structure at the hyphal tip and a band of septin bars around the base of newly evaginated germ tubes. The budding yeast Saccharomyces cerevisiae grows as yeast and pseudohyphae, but is not normally considered to show hyphal growth. We show here that in mating projections of both C. albicans and S. cerevisiae a Spitzenkörper-like structure is present at the growing tip and a band of septin bars is present at the base. Furthermore, in S. cerevisiae mating projections, Spa2 and Bni1 form a cap to the 3-dimensional ball of FM4-64 staining, exactly as previously observed in C. albicans hyphae, suggesting that the putative Spitzenkörper may be a distinct structure from the polarisome. Taken together this work shows that mating projections of both S. cerevisiae and C. albicans show the key characteristics of hyphal growth. Copyright © 2011 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  1. Effect of alcohols on filamentation, growth, viability and biofilm development in Candida albicans

    PubMed Central

    Chauhan, Nitin M; Shinde, Ravikumar B; Karuppayil, S. Mohan

    2013-01-01

    In this study we report the potential of alcohols as morphogenetic regulators in Candida albicans. All the alcohols tested influenced various modes of growth like planktonic as well as biofilm forms. Viability was affected at high concentrations. Among the alcohols, the response of C. albicans to amyl alcohol (pentanol) was noteworthy. Amyl alcohol at a concentration 0.5% which was not inhibitory to growth and viability specifically inhibited morphogenetic switching from yeast to hyphal forms. It also inhibited normal biofilm development favoring yeast dominated biofilms. Based on this study we hypothesize that alcohols produced under anaerobic conditions may not favor biofilm development and support dissemination of yeast cells. Since anaerobic conditions are not found to favor production of quorum sensing molecules like farnesol, the alcohols may play a role in morphogenetic regulation. PMID:24688528

  2. Prostaglandin E2 from Candida albicans Stimulates the Growth of Staphylococcus aureus in Mixed Biofilms

    PubMed Central

    Krause, Jan; Geginat, Gernot; Tammer, Ina

    2015-01-01

    Background Previous studies showed that Staphylococcus aureus and Candida albicans interact synergistically in dual species biofilms resulting in enhanced mortality in animal models. Methodology/Principal Findings The aim of the current study was to test possible candidate molecules which might mediate this synergistic interaction in an in vitro model of mixed biofilms, such as farnesol, tyrosol and prostaglandin (PG) E2. In mono-microbial and dual biofilms of C.albicans wild type strains PGE2 levels between 25 and 250 pg/mL were measured. Similar concentrations of purified PGE2 significantly enhanced S.aureus biofilm formation in a mode comparable to that observed in dual species biofilms. Supernatants of the null mutant deficient in PGE2 production did not stimulate the proliferation of S.aureus and the addition of the cyclooxygenase inhibitor indomethacin blocked the S.aureus biofilm formation in a dose-dependent manner. Additionally, S. aureus biofilm formation was boosted by low and inhibited by high farnesol concentrations. Supernatants of the farnesol-deficient C. albicans ATCC10231 strain significantly enhanced the biofilm formation of S. aureus but at a lower level than the farnesol producer SC5314. However, C. albicans ATCC10231 also produced PGE2 but amounts were significantly lower compared to SC5314. Conclusion/Significance In conclision, we identified C. albicans PGE2 as a key molecule stimulating the growth and biofilm formation of S. aureus in dual S. aureus/C. albicans biofilms, although C. albicans derived farnesol, but not tyrosol, may also contribute to this effect but to a lesser extent. PMID:26262843

  3. Boric acid destabilizes the hyphal cytoskeleton and inhibits invasive growth of Candida albicans.

    PubMed

    Pointer, Benjamin R; Boyer, Michael P; Schmidt, Martin

    2015-04-01

    Exposure of Candida albicans to sub-lethal concentrations of boric acid (BA) restricts the dimorphic fungus to its yeast morphology and prevents the formation of invasive hyphae on solid substrates. Exposure to BA causes a rapid and reversible disappearance of polarisome and Spitzenkörper in growing hyphae. In BA-treated hyphae of C. albicans, actin quickly reorganizes from cytoplasmic cables to cortical patches and cell wall growth switches from an apical to an isotropic pattern. As a result of the cytoskeletal changes, the hyphal tips broaden and directional growth of hyphae ceases in the presence of BA. An analysis of homozygous deletion strains showed that mutants with constitutive or enhanced hyphal growth (tup1, nrg1, ssn6, rbf1) are BA-sensitive, demonstrating that cellular morphology is a major determinant of BA tolerance. The screening of deletion mutants also showed that deficiencies of the main activator of hyphal gene expression, Efg1, and the Rim101-signalling cascade, leading to Efg1 activation, cause BA resistance. Taken together, the data presented show that the selective inhibitory effect on BA on C. albicans hyphae is rooted in a disruption of apical cytoskeletal elements of growing hyphae. Copyright © 2015 John Wiley & Sons, Ltd.

  4. Effect of edible sesame oil on growth of clinical isolates of Candida albicans.

    PubMed

    Ogawa, Toshiko; Nishio, Junko; Okada, Shinobu

    2014-07-01

    Elderly individuals are at increased risk of oral thrush (oral candidiasis) due to decreased saliva secretion. Due to their antimicrobial properties, edible oils can be effective natural agents for oral care. The objective of the present study was to compare the effects of sesame oil, which is widely used for cooking in Asian countries, and two other edible oils on the growth of both mycelial and yeast forms of five clinical isolates of Candida albicans, a causative microorganism of oral thrush. We assessed the effect of each oil in concentrations of 0.078%, 0.156%, and 0.313% on growth of the mycelial forms of the clinical isolates over 24 hr using the crystal violet method. We also evaluated the effect of each oil on growth of the yeast forms by counting the number of viable yeast cells after culturing in the oils for 24 hr. Sesame oil inhibited the growth of both mycelial and yeast forms. Safflower and olive oil also inhibited the growth of both forms of C. albicans but to a lesser extent than sesame oil. The ability to inhibit the growth of the mycelial form correlated with sesame oil concentration. Roasting influenced growth inhibition ability and high-roasted sesame oil most effectively inhibited the yeast form. The growth inhibitory effect differed among the five isolates. We hypothesize that the sesamin and fatty acid components of sesame oil are involved in its antifungal activity. © The Author(s) 2013.

  5. Effect of Growth Rate on Resistance of Candida albicans Biofilms to Antifungal Agents

    PubMed Central

    Baillie, George S.; Douglas, L. Julia

    1998-01-01

    A perfused biofilm fermentor, which allows growth-rate control of adherent microbial populations, was used to assess whether the susceptibility of Candida albicans biofilms to antifungal agents is dependent on growth rate. Biofilms were generated under conditions of glucose limitation and were perfused with drugs at a high concentration (20 times the MIC). Amphotericin B produced a greater reduction in the number of daughter cells in biofilm eluates than ketoconazole, fluconazole, or flucytosine. Similar decreases in daughter cell counts were observed when biofilms growing at three different rates were perfused with amphotericin B. In a separate series of experiments, intact biofilms, resuspended biofilm cells, and newly formed daughter cells were removed from the fermentor and were exposed to a lower concentration of amphotericin B for 1 h. The susceptibility profiles over a range of growth rates were then compared with those obtained for planktonic cells grown at the same rates under glucose limitation in a chemostat. Intact biofilms were resistant to amphotericin B at all growth rates tested, whereas planktonic cells were resistant only at low growth rates (≤0.13 h−1). Cells resuspended from biofilms were less resistant than intact biofilm populations but more resistant than daughter cells; the susceptibilities of both these cell types were largely independent of growth rate. Our findings indicate that the amphotericin B resistance of C. albicans biofilms is not simply due to a low growth rate but depends on some other feature of the biofilm mode of growth. PMID:9687381

  6. [Effect of Mexican propolis extracts from Apis mellifera on Candida albicans in vitro growth].

    PubMed

    Quintero-Mora, María Leonor; Londoño-Orozco, Amparo; Hernández-Hernández, Francisca; Manzano-Gayosso, Patricia; López-Martínez, Rubén; Soto-Zárate, Carlos Ignacio; Carrillo-Miranda, Liborio; Penieres-Carrillo, Guillermo; García-Tovar, Carlos Gerardo; Cruz-Sánchez, Tonatiuh A

    2008-03-01

    Propolis is a resinous substance collected by bees (Apis mellifera) from different trees and bushes. Due to its antifungal, antibacterial, antiviral and antiparasitic properties, it has continued to be very popular throughout the time showing variable activity depending on its geographical origin. In Mexico, information about this product is very limited. The aim of this work was to evaluate the antifungal activity of four propolis ethanolic extracts from three different Mexican states, and four commercial extracts on Candida albicans growth. A reference strain (ATCC 10231) and 36 clinical isolates of C. albicans were used. The Minimal Inhibitory Concentration (MIC) was determined by the dilution on agar method. Growth curves on Sabouraud Dextrose broth with and without different propolis ethanolic extracts concentrations were performed. In addition, whether the effect was fungistatic or fungicide was determined. The propolis ethanolic extract obtained from Cuautitlán Izcalli, State of Mexico, showed the best biological activity, inhibiting 94.4% from the clinical isolates at 0.8 mg/ml; the reference strain was inhibited at 0.6 mg/ml. The propolis effect was fungistatic in low concentrations and fungicide in concentrations higher to MIC. The Mexican propolis ethanolic extract could be further investigated for its alternative use for the treatment of some C. albicans infections.

  7. Cyclosporine A decreases the fluconazole minimum inhibitory concentration of Candida albicans clinical isolates but not biofilm formation and cell growth.

    PubMed

    Wibawa, T; Nurrokhman; Baly, I; Daeli, P R; Kartasasmita, G; Wijayanti, N

    2015-03-01

    Among the genus Candida, Candida albicans is the most abundant species in humans. One of the virulent factors of C. albicans is its ability to develop biofilm. Biofilm forming microbes are characterized by decreasing of its susceptibility to antibiotics and antifungal. The fungicidal effect of fluconazole may be enhanced by cyclosporine A in laboratory engineered C. albicans strains. The aim of this work is to analyze the synergistic effect of cyclosporine A with fluconazole in C. albicans clinical isolates and the effect of cycolsporine A alone in the biofilm formation. Six fluconazole resistant and six sensitive C. albicans clinical isolates were analyzed for its minimum inhibitory concentration (MICs), biofilm formation, and cell growths. A semi-quantitative XTT [2,3-bis(2-methoxy-4-nitro-5- sulfo-phenyl)-2H-tetrazolium-5-carboxanilide] reduction assay was conducted to measure the biofilm formation. Cyclosporine A has synergistic effect with fluconazole that was shown by decreasing MICs of both fluconazole resistant and sensitive C. albicans clinical isolates. However, cyclosporine A alone did not influence the biofilm formation and cell growth of both fluconazole resistant and sensitive C. albicans clinical isolates. These results indicated that cyclosporine A might be a promising candidate of adjuvant therapy for fluconazole against both fluconazole resistant and sensitive C. albicans clinical isolates.

  8. Probiotic lactobacilli inhibit early stages of Candida albicans biofilm development by reducing their growth, cell adhesion, and filamentation.

    PubMed

    Matsubara, Victor Haruo; Wang, Yi; Bandara, H M H N; Mayer, Marcia Pinto Alves; Samaranayake, Lakshman P

    2016-07-01

    We evaluated the inhibitory effects of the probiotic Lactobacillus species on different phases of Candida albicans biofilm development. Quantification of biofilm growth and ultrastructural analyses were performed on C. albicans biofilms treated with Lactobacillus rhamnosus, Lactobacillus casei, and Lactobacillus acidophilus planktonic cell suspensions as well as their supernatants. Planktonic lactobacilli induced a significant reduction (p < 0.05) in the number of biofilm cells (25.5-61.8 %) depending on the probiotic strain and the biofilm phase. L. rhamnosus supernatants had no significant effect on the mature biofilm (p > 0.05), but significantly reduced the early stages of Candida biofilm formation (p < 0.01). Microscopic analyses revealed that L. rhamnosus suspensions reduced Candida hyphal differentiation, leading to a predominance of budding growth. All lactobacilli negatively impacted C. albicans yeast-to-hyphae differentiation and biofilm formation. The inhibitory effects of the probiotic Lactobacillus on C. albicans entailed both cell-cell interactions and secretion of exometabolites that may impact on pathogenic attributes associated with C. albicans colonization on host surfaces and yeast filamentation. This study clarifies, for the first time, the mechanics of how Lactobacillus species may antagonize C. albicans host colonization. Our data elucidate the inhibitory mechanisms that define the probiotic candicidal activity of lactobacilli, thus supporting their utility as an adjunctive therapeutic mode against mucosal candidal infections.

  9. Carvone and perillaldehyde interfere with the serum-induced formation of filamentous structures in Candida albicans at substantially lower concentrations than those causing significant inhibition of growth.

    PubMed

    McGeady, Paul; Wansley, Daniel L; Logan, David A

    2002-07-01

    Carvone and perillaldehyde were shown to inhibit the transformation of Candida albicans to a filamentous form at concentrations far lower and more biologically relevant than the concentrations necessary to inhibit growth. This morphological transformation is associated with C. albicans pathogenicity; hence these naturally occurring monoterpenes are potential lead compounds in the development of therapeutic agents against C. albicans infection.

  10. Platelet interactions with Candida albicans.

    PubMed Central

    Skerl, K G; Calderone, R A; Sreevalsan, T

    1981-01-01

    The interaction of human platelets and Candida albicans was studied. Platelet-rich plasma was obtained from freshly drawn blood or outdated platelet concentrates. From the platelet-rich plasma, a platelet extract was derived which stimulated germ tube formation by C. albicans when incubated with yeast cells at 37 degrees C. The active component(s) was heat stable, trypsin sensitive, and ribonuclease and deoxyribonuclease insensitive, and possessed cationic properties since it readily attached to carboxymethyl-Sephadex. The active component(s) seemed to bind to heparin also, since germ tube-promoting activity was eluted from a heparin-cyanogen bromide-activated Sepharose 4B column. In addition, platelet-derived growth factor (Collaborative Research, Inc.) stimulated germination when incubated with low amounts (0.4% final concentration) of bovine calf serum. The aggregation of platelets, prepared as platelet-rich plasma by C. albicans cell wall or alkali-extracted cell wall fractions, was also studied. Aggregation of platelets was observed when cell wall or cell wall fractions were incubated with platelet-poor plasma at 37 degrees C for 20 min and then added to platelet-rich plasma. The component of platelet-poor plasma which promoted aggregation of platelets by C. albicans cell wall or alkali-extracted fractions was inactivated at 56 degrees C (30 min) and by cobra venom factor, indicating a role for the alternate complement pathway in the aggregation response. PMID:7037646

  11. PMT family of Candida albicans: five protein mannosyltransferase isoforms affect growth, morphogenesis and antifungal resistance.

    PubMed

    Prill, Stephan K-H; Klinkert, Birgit; Timpel, Claudia; Gale, Cheryl A; Schröppel, Klaus; Ernst, Joachim F

    2005-01-01

    Protein O-mannosyltransferases (Pmt proteins) initiate O-mannosylation of secretory proteins. The PMT gene family of the human fungal pathogen Candida albicans consists of PMT1 and PMT6, as well as three additional PMT genes encoding Pmt2, Pmt4 and Pmt5 isoforms described here. Both PMT2 alleles could not be deleted and growth of conditional strains, containing PMT2 controlled by the MET3- or tetOScHOP1-promoters, was blocked in non-permissive conditions, indicating that PMT2 is essential for growth. A homozygous pmt4 mutant was viable, but synthetic lethality of pmt4 was observed in combination with pmt1 mutations. Hyphal morphogenesis of a pmt4 mutant was defective under aerobic induction conditions, yet increased in embedded or hypoxic conditions, suggesting a role of Pmt4p-mediated O-glycosylation for environment-specific morphogenetic signalling. Although a PMT5 transcript was detected, a homozygous pmt5 mutant was phenotypically silent. All other pmt mutants showed variable degrees of supersensitivity to antifungals and to cell wall-destabilizing agents. Cell wall composition was markedly affected in pmt1 and pmt4 mutants, showing a significant decrease in wall mannoproteins. In a mouse model of haematogenously disseminated infection, PMT4 was required for full virulence of C. albicans. Functional analysis of the first complete PMT gene family in a fungal pathogen indicates that Pmt isoforms have variable and specific roles for in vitro and in vivo growth, morphogenesis and antifungal resistance.

  12. Spt3 plays opposite roles in filamentous growth in Saccharomyces cerevisiae and Candida albicans and is required for C. albicans virulence.

    PubMed Central

    Laprade, Lisa; Boyartchuk, Victor L; Dietrich, William F; Winston, Fred

    2002-01-01

    Spt3 of Saccharomyces cerevisiae is required for the normal transcription of many genes in vivo. Past studies have shown that Spt3 is required for both mating and sporulation, two events that initiate when cells are at G(1)/START. We now show that Spt3 is needed for two other events that begin at G(1)/START, diploid filamentous growth and haploid invasive growth. In addition, Spt3 is required for normal expression of FLO11, a gene required for filamentous growth, although this defect is not the sole cause of the spt3Delta/spt3Delta filamentous growth defect. To extend our studies of Spt3's role in filamentous growth to the pathogenic yeast Candida albicans, we have identified the C. albicans SPT3 gene and have studied its role in C. albicans filamentous growth and virulence. Surprisingly, C. albicans spt3Delta/spt3Delta mutants are hyperfilamentous, the opposite phenotype observed for S. cerevisiae spt3Delta/spt3Delta mutants. Furthermore, C. albicans spt3Delta/spt3Delta mutants are avirulent in mice. These experiments demonstrate that Spt3 plays important but opposite roles in filamentous growth in S. cerevisiae and C. albicans. PMID:12072450

  13. Bismuth oxide aqueous colloidal nanoparticles inhibit Candida albicans growth and biofilm formation.

    PubMed

    Hernandez-Delgadillo, Rene; Velasco-Arias, Donaji; Martinez-Sanmiguel, Juan Jose; Diaz, David; Zumeta-Dube, Inti; Arevalo-Niño, Katiushka; Cabral-Romero, Claudio

    2013-01-01

    Multiresistance among microorganisms to common antimicrobials has become one of the most significant concerns in modern medicine. Nanomaterials are a new alternative to successfully treat the multiresistant microorganisms. Nanostructured materials are used in many fields, including biological sciences and medicine. Recently, it was demonstrated that the bactericidal activity of zero-valent bismuth colloidal nanoparticles inhibited the growth of Streptococcus mutans; however the antimycotic potential of bismuth nanostructured derivatives has not yet been studied. The main objective of this investigation was to analyze the fungicidal activity of bismuth oxide nanoparticles against Candida albicans, and their antibiofilm capabilities. Our results showed that aqueous colloidal bismuth oxide nanoparticles displayed antimicrobial activity against C. albicans growth (reducing colony size by 85%) and a complete inhibition of biofilm formation. These results are better than those obtained with chlorhexidine, nystatin, and terbinafine, the most effective oral antiseptic and commercial antifungal agents. In this work, we also compared the antimycotic activities of bulk bismuth oxide and bismuth nitrate, the precursor metallic salt. These results suggest that bismuth oxide colloidal nanoparticles could be a very interesting candidate as a fungicidal agent to be incorporated into an oral antiseptic. Additionally, we determined the minimum inhibitory concentration for the synthesized aqueous colloidal Bi2O3 nanoparticles.

  14. Bismuth oxide aqueous colloidal nanoparticles inhibit Candida albicans growth and biofilm formation

    PubMed Central

    Hernandez-Delgadillo, Rene; Velasco-Arias, Donaji; Martinez-Sanmiguel, Juan Jose; Diaz, David; Zumeta-Dube, Inti; Arevalo-Niño, Katiushka; Cabral-Romero, Claudio

    2013-01-01

    Multiresistance among microorganisms to common antimicrobials has become one of the most significant concerns in modern medicine. Nanomaterials are a new alternative to successfully treat the multiresistant microorganisms. Nanostructured materials are used in many fields, including biological sciences and medicine. Recently, it was demonstrated that the bactericidal activity of zero-valent bismuth colloidal nanoparticles inhibited the growth of Streptococcus mutans; however the antimycotic potential of bismuth nanostructured derivatives has not yet been studied. The main objective of this investigation was to analyze the fungicidal activity of bismuth oxide nanoparticles against Candida albicans, and their antibiofilm capabilities. Our results showed that aqueous colloidal bismuth oxide nanoparticles displayed antimicrobial activity against C. albicans growth (reducing colony size by 85%) and a complete inhibition of biofilm formation. These results are better than those obtained with chlorhexidine, nystatin, and terbinafine, the most effective oral antiseptic and commercial antifungal agents. In this work, we also compared the antimycotic activities of bulk bismuth oxide and bismuth nitrate, the precursor metallic salt. These results suggest that bismuth oxide colloidal nanoparticles could be a very interesting candidate as a fungicidal agent to be incorporated into an oral antiseptic. Additionally, we determined the minimum inhibitory concentration for the synthesized aqueous colloidal Bi2O3 nanoparticles. PMID:23637533

  15. Candida albicans OPI1 Regulates Filamentous Growth and Virulence in Vaginal Infections, but Not Inositol Biosynthesis

    PubMed Central

    Chen, Ying-Lien; de Bernardis, Flavia; Yu, Shang-Jie; Sandini, Silvia; Kauffman, Sarah; Tams, Robert N.; Bethea, Emily; Reynolds, Todd B.

    2015-01-01

    ScOpi1p is a well-characterized transcriptional repressor and master regulator of inositol and phospholipid biosynthetic genes in the baker’s yeast Saccharomyces cerevisiae. An ortholog has been shown to perform a similar function in the pathogenic fungus Candida glabrata, but with the distinction that CgOpi1p is essential for growth in this organism. However, in the more distantly related yeast Yarrowia lipolytica, the OPI1 homolog was not found to regulate inositol biosynthesis, but alkane oxidation. In Candida albicans, the most common cause of human candidiasis, its Opi1p homolog, CaOpi1p, has been shown to complement a S. cerevisiae opi1∆ mutant for inositol biosynthesis regulation when heterologously expressed, suggesting it might serve a similar role in this pathogen. This was tested in the pathogen directly in this report by disrupting the OPI1 homolog and examining its phenotypes. It was discovered that the OPI1 homolog does not regulate INO1 expression in C. albicans, but it does control SAP2 expression in response to bovine serum albumin containing media. Meanwhile, we found that CaOpi1 represses filamentous growth at lower temperatures (30°C) on agar, but not in liquid media. Although, the mutant does not affect virulence in a mouse model of systemic infection, it does affect virulence in a rat model of vaginitis. This may be because Opi1p regulates expression of the SAP2 protease, which is required for rat vaginal infections. PMID:25602740

  16. The MARVEL domain protein Nce102 regulates actin organization and invasive growth of Candida albicans.

    PubMed

    Douglas, Lois M; Wang, Hong X; Konopka, James B

    2013-11-26

    Invasive growth of the fungal pathogen Candida albicans into tissues promotes disseminated infections in humans. The plasma membrane is essential for pathogenesis because this important barrier mediates morphogenesis and invasive growth, as well as secretion of virulence factors, cell wall synthesis, nutrient import, and other processes. Previous studies showed that the Sur7 tetraspan protein that localizes to MCC (membrane compartment occupied by Can1)/eisosome subdomains of the plasma membrane regulates a broad range of key functions, including cell wall synthesis, morphogenesis, and resistance to copper. Therefore, a distinct tetraspan protein found in MCC/eisosomes, Nce102, was investigated. Nce102 belongs to the MARVEL domain protein family, which is implicated in regulating membrane structure and function. Deletion of NCE102 did not cause the broad defects seen in sur7Δ cells. Instead, the nce102Δ mutant displayed a unique phenotype in that it was defective in forming hyphae and invading low concentrations of agar but could invade well in higher agar concentrations. This phenotype was likely due to a defect in actin organization that was observed by phalloidin staining. In support of this, the invasive growth defect of a bni1Δ mutant that mislocalizes actin due to lack of the Bni1 formin was also reversed at high agar concentrations. This suggests that a denser matrix provides a signal that compensates for the actin defects. The nce102Δ mutant displayed decreased virulence and formed abnormal hyphae in mice. These studies identify novel ways that Nce102 and the physical environment surrounding C. albicans regulate morphogenesis and pathogenesis. The plasma membrane promotes virulence of the human fungal pathogen Candida albicans by acting as a protective barrier around the cell and mediating dynamic activities, such as morphogenesis, cell wall synthesis, secretion of virulence factors, and nutrient uptake. To better understand how the plasma membrane

  17. NADPH Oxidase-Driven Phagocyte Recruitment Controls Candida albicans Filamentous Growth and Prevents Mortality

    PubMed Central

    Brothers, Kimberly M.; Gratacap, Remi L.; Barker, Sarah E.; Newman, Zachary R.; Norum, Ashley; Wheeler, Robert T.

    2013-01-01

    Candida albicans is a human commensal and clinically important fungal pathogen that grows as both yeast and hyphal forms during human, mouse and zebrafish infection. Reactive oxygen species (ROS) produced by NADPH oxidases play diverse roles in immunity, including their long-appreciated function as microbicidal oxidants. Here we demonstrate a non-traditional mechanistic role of NADPH oxidase in promoting phagocyte chemotaxis and intracellular containment of fungi to limit filamentous growth. We exploit the transparent zebrafish model to show that failed NADPH oxidase-dependent phagocyte recruitment to C. albicans in the first four hours post-infection permits fungi to germinate extracellularly and kill the host. We combine chemical and genetic tools with high-resolution time-lapse microscopy to implicate both phagocyte oxidase and dual-specific oxidase in recruitment, suggesting that both myeloid and non-myeloid cells promote chemotaxis. We show that early non-invasive imaging provides a robust tool for prognosis, strongly connecting effective early immune response with survival. Finally, we demonstrate a new role of a key regulator of the yeast-to-hyphal switching program in phagocyte-mediated containment, suggesting that there are species-specific methods for modulation of NADPH oxidase-independent immune responses. These novel links between ROS-driven chemotaxis and fungal dimorphism expand our view of a key host defense mechanism and have important implications for pathogenesis. PMID:24098114

  18. Inhibitory effects of several saturated fatty acids and their related fatty alcohols on the growth of Candida albicans.

    PubMed

    Hayama, Kazumi; Takahashi, Miki; Yui, Satoru; Abe, Shigeru

    2015-12-01

    We examined the effect of 5 saturated fatty acids and their related alcohols on the growth of Candida albicans. The inhibitory effects of these compounds against the yeast and hyphal growth forms of C. albicans were examined using the modified NCCLS method and crystal violet staining, respectively. Among these compounds, capric acid inhibited both types of growth at the lowest concentration. The IC(80), i.e., the concentration at which the compounds reduced the growth of C. albicans by 80% in comparison with the growth of control cells, of capric acid for the hyphal growth of this fungus, which is indispensable for its mucosal invasion, was 16.7 μM. These fatty acids, including capric acid, have an unpleasant smell, which may limit their therapeutic use. To test them at reduced concentrations, the combined effect of these fatty acids and oligonol, a depolymerized polyphenol, was evaluated in vitro. These combinations showed potent synergistic inhibition of hyphal growth [fractional inhibitory concentration (FIC) index = 0.319]. Our results demonstrated that capric acid combined with oligonol could be used as an effective anti-Candida compound. It may be a candidate prophylactic or therapeutic tool against mucosal Candida infection.

  19. Candida albicans White and Opaque Cells Undergo Distinct Programs of Filamentous Growth

    PubMed Central

    Si, Haoyu; Hernday, Aaron D.; Hirakawa, Matthew P.; Johnson, Alexander D.; Bennett, Richard J.

    2013-01-01

    The ability to switch between yeast and filamentous forms is central to Candida albicans biology. The yeast-hyphal transition is implicated in adherence, tissue invasion, biofilm formation, phagocyte escape, and pathogenesis. A second form of morphological plasticity in C. albicans involves epigenetic switching between white and opaque forms, and these two states exhibit marked differences in their ability to undergo filamentation. In particular, filamentous growth in white cells occurs in response to a number of environmental conditions, including serum, high temperature, neutral pH, and nutrient starvation, whereas none of these stimuli induce opaque filamentation. Significantly, however, we demonstrate that opaque cells can undergo efficient filamentation but do so in response to distinct environmental cues from those that elicit filamentous growth in white cells. Growth of opaque cells in several environments, including low phosphate medium and sorbitol medium, induced extensive filamentous growth, while white cells did not form filaments under these conditions. Furthermore, while white cell filamentation is often enhanced at elevated temperatures such as 37°C, opaque cell filamentation was optimal at 25°C and was inhibited by higher temperatures. Genetic dissection of the opaque filamentation pathway revealed overlapping regulation with the filamentous program in white cells, including key roles for the transcription factors EFG1, UME6, NRG1 and RFG1. Gene expression profiles of filamentous white and opaque cells were also compared and revealed only limited overlap between these programs, although UME6 was induced in both white and opaque cells consistent with its role as master regulator of filamentation. Taken together, these studies establish that a program of filamentation exists in opaque cells. Furthermore, this program regulates a distinct set of genes and is under different environmental controls from those operating in white cells. PMID:23505370

  20. Candida albicans white and opaque cells undergo distinct programs of filamentous growth.

    PubMed

    Si, Haoyu; Hernday, Aaron D; Hirakawa, Matthew P; Johnson, Alexander D; Bennett, Richard J

    2013-03-01

    The ability to switch between yeast and filamentous forms is central to Candida albicans biology. The yeast-hyphal transition is implicated in adherence, tissue invasion, biofilm formation, phagocyte escape, and pathogenesis. A second form of morphological plasticity in C. albicans involves epigenetic switching between white and opaque forms, and these two states exhibit marked differences in their ability to undergo filamentation. In particular, filamentous growth in white cells occurs in response to a number of environmental conditions, including serum, high temperature, neutral pH, and nutrient starvation, whereas none of these stimuli induce opaque filamentation. Significantly, however, we demonstrate that opaque cells can undergo efficient filamentation but do so in response to distinct environmental cues from those that elicit filamentous growth in white cells. Growth of opaque cells in several environments, including low phosphate medium and sorbitol medium, induced extensive filamentous growth, while white cells did not form filaments under these conditions. Furthermore, while white cell filamentation is often enhanced at elevated temperatures such as 37°C, opaque cell filamentation was optimal at 25°C and was inhibited by higher temperatures. Genetic dissection of the opaque filamentation pathway revealed overlapping regulation with the filamentous program in white cells, including key roles for the transcription factors EFG1, UME6, NRG1 and RFG1. Gene expression profiles of filamentous white and opaque cells were also compared and revealed only limited overlap between these programs, although UME6 was induced in both white and opaque cells consistent with its role as master regulator of filamentation. Taken together, these studies establish that a program of filamentation exists in opaque cells. Furthermore, this program regulates a distinct set of genes and is under different environmental controls from those operating in white cells.

  1. Absence of Photoreactivating Enzyme in Candida albicans, Candida stellatoidea, and Candida tropicalis

    PubMed Central

    Miller, Glendon R.; Sarachek, Alvin

    1974-01-01

    In vitro assays demonstrate photoreactivating enzyme activity in extracts of Candida pseudotropicalis but not in extracts of Candida albicans, Candida stellatoidea, or Candida tropicalis. PMID:4604052

  2. Suppression of polymorphonuclear (PMN) and monocyte-mediated inhibition of Candida albicans growth by delta-9-tetrahydrocannabinol

    SciTech Connect

    Djeu, J.Y.; Parapanios, A.; Halkias, D.; Friedman, H.

    1986-03-05

    This study was an in vitro attempt to identify the effector cells responsible for growth inhibition of the opportunistic fungus, candida albicans, and to determine if THC or another marijuana derivatives, 11-hydroxyTHC, would adversely affect their function. Using a 24h radiolabel assay, the authors found that growth inhibition of C. albicans was primarily mediated by PMN and monocytes that could be isolated normal human peripheral blood. Both effector cell types caused almost complete inhibition of Candida growth at effector/target ratio of 300/1 and inhibition was often still seen at 30/1-. Incubation of PMN, PBL, or monocytes for 1 hr at 37C with THC or 11-hydroxyTHC caused a marked suppression of function in all 3 cell populations. Maximal suppression was obtained with 7.5-10..mu..g/ml of the drugs in medium containing 10% fetal bovine serum (FBS) or with 2-4..mu..g/ml in 1% FBS. These drug concentrations did not affect lymphoid cell viability or candida growth in the absence of lymphoid effector cells. Marijuana derivatives, therefore, are doubly dangerous in that opportunistic fungi such as C. albicans can grow in their presence while the effector cells that control fungal growth are readily inactivated.

  3. Inhibition of Candida albicans by methanethiol produced by Brevibacterium linens.

    PubMed

    Lewis, B A

    1985-10-01

    Brevibacterium linens was screened for antifungal activity against Candida albicans using several antibiotic assay methods. The growth of C. albicans was inhibited only when the dual culture assay method was employed and using methionine-supplemented media. Results suggest that methanethiol which is produced by B. linens' utilization of methionine is the agent inhibitory to C. albicans' growth.

  4. Tramadol, an Opioid Receptor Agonist: An Inhibitor of Growth, Morphogenesis, and Biofilm Formation in the Human Pathogen, Candida albicans.

    PubMed

    Kathwate, Gunderao Hanumantrao; Karuppayil, S Mohan

    2016-12-01

    Tramadol is a synthetic, centrally acting low-affinity agonist of μ-opioid receptors in humans. It is used as an analgesic and is shown to have local anesthetic action. In this study, we have tried to explore its anti-Candida potential. Minimum inhibitory concentration (MIC50) and minimum fungicidal concentration (MFC) values were established. MIC50 ranged from 2 to 4 mg/mL, whereas MFC was recorded at 8 mg/mL. Also, the effect of tramadol on germ tube formation, adhesion, and biofilms in Candida albicans was studied. Tramadol impaired in vitro growth of C. albicans. A time-dependent killing assay showed that it kills C. albicans within 24 h of exposure. Tramadol has strong activity against Candida virulence factors such as yeast-to-hyphal form switching and adhesion. C. albicans biofilms, which are notoriously resistant to many antifungals, were sensitive to tramadol. At 8 mg/mL of tramadol, 82% of early stage biofilms and 52.88% of matured biofilms were inhibited. Although our results show that the antifungal effect of tramadol requires concentrations that can be achieved only locally, they may provide potential candidates for development of novel antifungal drugs.

  5. Development of DNA probes for Candida albicans

    SciTech Connect

    Cheung, L.L.; Hudson, J.B.

    1988-07-01

    An attempt was made to produce DNA probes that could be used as a rapid and efficient means of detecting candidiasis (invasive Candida infection) in immunocompromised patients. Whole DNA from Candida albicans was digested with restriction endonuclease, and the resulting fragments were randomly cloned into a plasmid vector. Several recombinant plasmids were evaluated for cross-hybridization to various other Candida species, other fungal DNAs, and to nonfungal DNAs. Cross reactions were observed between the probes and different yeasts, but none with unrelated DNAs. Some recombinants were genus-specific, and two of these were applied to the analysis of C. albicans growth curves. It became evident that, although both /sup 32/P- and biotin-labelled probes could be made quite sensitive, a possible limitation in their diagnostic potential was the poor liberation of Candida DNA from cells. Thus, better methods of treatment of clinical specimens will be required before such probes will be useful in routine diagnosis.

  6. Pentamidine Inhibition of Group I Intron Splicing in Candida albicans Correlates with Growth Inhibition

    PubMed Central

    Miletti, Karl E.; Leibowitz, Michael J.

    2000-01-01

    We previously demonstrated that pentamidine, which has been clinically used against Pneumocystis carinii, inhibits in vitro a group I intron ribozyme from that organism. Another fungal pathogen, Candida albicans, also harbors a group I intron ribozyme (Ca.LSU) in the essential rRNA genes in almost half of the clinical isolates analyzed. To determine whether pentamidine inhibits Ca.LSU in vitro and in cells, phylogenetically closely related intron-containing (4-1) and intronless (62-1) strains were studied. Splicing in vitro of the Ca.LSU group I intron ribozyme was completely inhibited by pentamidine at 200 μM. On rich glucose medium, the intron-containing strain was more sensitive to growth inhibition by pentamidine than was the intronless strain, as measured by disk or broth microdilution assays. On rich glycerol medium, they were equally susceptible to pentamidine. At pentamidine levels selectively inhibiting the intron-containing strain (1 μM) in glucose liquid cultures, inhibition of splicing and rRNA maturation was detected by quantitative reverse transcription-PCR within 1 min with a 10- to 15-fold accumulation of precursor rRNA. No comparable effect was seen in the intronless strain. These results correlate the cellular splicing inhibition of Ca.LSU with the growth inhibition of strain 4-1 harboring Ca.LSU. Broth microdilution assays of 13 Candida strains showed that intron-containing strains were generally more susceptible to pentamidine than the intronless strains. Our data suggest that ribozymes found in pathogenic microorganisms but absent in mammals may be targets for antimicrobial therapy. PMID:10722497

  7. Adaptations of Candida albicans for growth in the mammalian intestinal tract.

    PubMed

    Rosenbach, Ari; Dignard, Daniel; Pierce, Jessica V; Whiteway, Malcolm; Kumamoto, Carol A

    2010-07-01

    Although the fungus Candida albicans is a commensal colonizer of humans, the organism is also an important opportunistic pathogen. Most infections caused by C. albicans arise from organisms that were previously colonizing the host as commensals, and therefore successful establishment of colonization is a prerequisite for pathogenicity. To elucidate fungal activities that promote colonization, an analysis of the transcription profile of C. albicans cells recovered from the intestinal tracts of mice was performed. The results showed that within the C. albicans colonizing population, cells expressed genes characteristic of the laboratory-grown exponential phase and genes characteristic of post-exponential-phase cells. Thus, gene expression both promoted the ability to grow rapidly (a characteristic of exponential-phase cells) and enhanced the ability to resist stresses (a characteristic of post-exponential-phase cells). Similarities in gene expression in commensal colonizing cells and cells invading host tissue during disease were found, showing that C. albicans cells adopt a particular cell surface when growing within a host in both situations. In addition, transcription factors Cph2p and Tec1p were shown to regulate C. albicans gene expression during intestinal colonization.

  8. Growth of Candida albicans Cells on the Physiologically Relevant Carbon Source Lactate Affects Their Recognition and Phagocytosis by Immune Cells

    PubMed Central

    Ene, Iuliana V.; Cheng, Shih-Chin; Netea, Mihai G.

    2013-01-01

    Candida albicans is a normal resident of the human gastrointestinal and urogenital tracts and also a prevalent fungal pathogen. During both commensalism and infection, it must match the immunological defenses of its host while adapting to environmental cues and the local nutrient status. C. albicans regularly colonizes glucose-poor niches, thereby depending upon alternative carbon sources for growth. However, most studies of host immune responses to C. albicans have been performed on fungal cells grown on glucose, and the extent to which alternative physiologically relevant carbon sources impact innate immune responses has not been studied. The fungal cell wall is decorated with multifarious pathogen-associated molecular patterns and is the main target for recognition by host innate immune cells. Cell wall architecture is both robust and dynamic, and it is dramatically influenced by growth conditions. We found that growth of C. albicans cells on lactate, a nonfermentative carbon source available in numerous anatomical niches, modulates their interactions with immune cells and the resultant cytokine profile. Notably, lactate-grown C. albicans stimulated interleukin-10 (IL-10) production while decreasing IL-17 levels, rendering these cells less visible to the immune system than were glucose-grown cells. This trend was observed in clinical C. albicans isolates from different host niches and from different epidemiological clades. In addition, lactate-grown C. albicans cells were taken up by macrophages less efficiently, but they were more efficient at killing and escaping these phagocytic cells. Our data indicate that carbon source has a major impact upon the C. albicans interaction with the innate immune system. PMID:23115042

  9. Regulation of the Cdc42/Cdc24 GTPase Module during Candida albicans Hyphal Growth

    PubMed Central

    Bassilana, Martine; Hopkins, Julie; Arkowitz, Robert A.

    2005-01-01

    The Rho G protein Cdc42 and its exchange factor Cdc24 are required for hyphal growth of the human fungal pathogen Candida albicans. Previously, we reported that strains ectopically expressing Cdc24 or Cdc42 are unable to form hyphae in response to serum. Here we investigated the role of these two proteins in hyphal growth, using quantitative real-time PCR to measure induction of hypha-specific genes together with time lapse microscopy. Expression of the hypha-specific genes examined depends on the cyclic AMP-dependent protein kinase A pathway culminating in the Efg1 and Tec1 transcription factors. We show that strains with reduced levels of CDC24 or CDC42 transcripts induce hypha-specific genes yet cannot maintain their expression in response to serum. Furthermore, in serum these mutants form elongated buds compared to the wild type and mutant budding cells, as observed by time lapse microscopy. Using Cdc24 fused to green fluorescent protein, we also show that Cdc24 is recruited to and persists at the germ tube tip during hyphal growth. Altogether these data demonstrate that the Cdc24/Cdc42 GTPase module is required for maintenance of hyphal growth. In addition, overexpression studies indicate that specific levels of Cdc24 and Cdc42 are important for invasive hyphal growth. In response to serum, CDC24 transcript levels increase transiently in a Tec1-dependent fashion, as do the G-protein RHO3 and the Rho1 GTPase activating protein BEM2 transcript levels. These results suggest that a positive feedback loop between Cdc24 and Tec1 contributes to an increase in active Cdc42 at the tip of the germ tube which is important for hypha formation. PMID:15755921

  10. Candida albicans: adapting to succeed.

    PubMed

    Kadosh, David; Lopez-Ribot, Jose L

    2013-11-13

    In this issue of Cell Host & Microbe, Lu et al. (2013) report on the redundancy of signaling pathways controlling Candida albicans filamentation and pathogenicity. In the process, they provide important insight into how this normal commensal of humans adapts to different host microenvironments to become a highly successful opportunistic pathogen.

  11. Hyphal growth in Candida albicans does not require induction of hyphal-specific gene expression

    PubMed Central

    Naseem, Shamoon; Araya, Esteban; Konopka, James B.

    2015-01-01

    Various stimuli, including N-acetylglucosamine (GlcNAc), induce the fungal pathogen Candida albicans to switch from budding to hyphal growth. Previous studies suggested that hyphal morphogenesis is stimulated by transcriptional induction of a set of genes that includes known virulence factors. To better understand hyphal development, we examined the role of GlcNAc metabolism using a triple mutant lacking the genes required to metabolize exogenous GlcNAc (hxk1Δ nag1Δ dac1Δ). Surprisingly, at low ambient pH (∼pH 4), GlcNAc stimulated this mutant to form hyphae without obvious induction of hyphal genes. This indicates that GlcNAc can stimulate a separate signal to induce hyphae that is independent of transcriptional responses. Of interest, GlcNAc could induce the triple mutant to express hyphal genes when the medium was buffered to a higher pH (>pH 5), which normally occurs after GlcNAc catabolism. Catabolism of GlcNAc raises the ambient pH rather than acidifying it, as occurs after dextrose catabolism. This synergy between alkalinization and GlcNAc to induce hyphal genes involves the Rim101 pH-sensing pathway; GlcNAc induced rim101Δ and dfg16Δ mutants to form hyphae, but hyphal gene expression was partially defective. These results demonstrate that hyphal morphogenesis and gene expression can be regulated independently, which likely contributes to pathogenesis at different host sites. PMID:25609092

  12. Comparative antifungal susceptibility analysis of Candida albicans versus non-albicans Candida corneal isolates.

    PubMed

    Spierer, Oriel; Dugar, Jyoti; Miller, Darlene; OʼBrien, Terrence P

    2015-05-01

    To compare the in vitro activity of topical amphotericin B (AMB), natamycin, voriconazole, and fluconazole against human corneal isolates of Candida sp. for guidance in the treatment of Candida keratitis. Sixty-eight Candida isolates (37 albicans and 31 non-albicans isolates) recovered from corneal scrapings submitted to rule out microbial keratitis, during the years 2005 to 2011, at the Bascom Palmer Eye Institute, were examined in this study. Corneal isolates were cultured on fungal agars for 48 hours. Each yeast isolate was dispensed into 4 microtiter wells, each containing 100 mL of commercial (natamycin 5%) or compounded (AMB 0.15%, voriconazole 1%, and fluconazole 0.2%) antifungal medications. A comparison of growth patterns was conducted. One hundred percent of the samples showed growth inhibition after treatment exposure with AMB or natamycin. The isolates treated with voriconazole demonstrated an 85% inhibition rate overall, with the Candida albicans samples showing a 77% inhibition rate and the non-albicans sp. a 93% inhibition rate. In the fluconazole group, there was only a 19.6% inhibition rate noted, with a 7.7% inhibition rate observed in the C. albicans group versus a 30% inhibition rate in the non-albicans group. AMB 0.2% and natamycin 5% have equal effectiveness and full inhibition against Candida keratitis isolates. Fluconazole 0.2% is not the drug of choice in both C. albicans and non-albicans keratitis. Voriconazole 1% may need a stronger concentration for higher effectiveness, but potentially may be helpful as a second agent in the treatment of Candida keratitis.

  13. Inhibitory Effect of Sophorolipid on Candida albicans Biofilm Formation and Hyphal Growth

    PubMed Central

    Haque, Farazul; Alfatah, Md.; Ganesan, K.; Bhattacharyya, Mani Shankar

    2016-01-01

    Candida albicans causes superficial and life-threatening systemic infections. These are difficult to treat often due to drug resistance, particularly because C. albicans biofilms are inherently resistant to most antifungals. Sophorolipid (SL), a glycolipid biosurfactant, has been shown to have antimicrobial and anticancer properties. In this study, we investigated the effect of SL on C. albicans biofilm formation and preformed biofilms. SL was found to inhibit C. albicans biofilm formation as well as reduce the viability of preformed biofilms. Moreover, SL, when used along with amphotericin B (AmB) or fluconazole (FLZ), was found to act synergistically against biofilm formation and preformed biofilms. Effect of SL on C. albicans biofilm formation was further visualized by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), which revealed absence of hyphae, typical biofilm architecture and alteration in the morphology of biofilm cells. We also found that SL downregulates the expression of hypha specific genes HWP1, ALS1, ALS3, ECE1 and SAP4, which possibly explains the inhibitory effect of SL on hyphae and biofilm formation. PMID:27030404

  14. Inhibitory Effect of Sophorolipid on Candida albicans Biofilm Formation and Hyphal Growth.

    PubMed

    Haque, Farazul; Alfatah, Md; Ganesan, K; Bhattacharyya, Mani Shankar

    2016-03-31

    Candida albicans causes superficial and life-threatening systemic infections. These are difficult to treat often due to drug resistance, particularly because C. albicans biofilms are inherently resistant to most antifungals. Sophorolipid (SL), a glycolipid biosurfactant, has been shown to have antimicrobial and anticancer properties. In this study, we investigated the effect of SL on C. albicans biofilm formation and preformed biofilms. SL was found to inhibit C. albicans biofilm formation as well as reduce the viability of preformed biofilms. Moreover, SL, when used along with amphotericin B (AmB) or fluconazole (FLZ), was found to act synergistically against biofilm formation and preformed biofilms. Effect of SL on C. albicans biofilm formation was further visualized by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), which revealed absence of hyphae, typical biofilm architecture and alteration in the morphology of biofilm cells. We also found that SL downregulates the expression of hypha specific genes HWP1, ALS1, ALS3, ECE1 and SAP4, which possibly explains the inhibitory effect of SL on hyphae and biofilm formation.

  15. An assessment of growth media enrichment on lipid metabolome and the concurrent phenotypic properties of Candida albicans.

    PubMed

    Mahto, Kaushal Kumar; Singh, Ashutosh; Khandelwal, Nitesh Kumar; Bhardwaj, Nitin; Jha, Jaykar; Prasad, Rajendra

    2014-01-01

    A critical question among the researchers working on fungal lipid biology is whether the use of an enriched growth medium can affect the lipid composition of a cell and, therefore, contribute to the observed phenotypes. One presumption is that enriched medias, such as YPD (yeast extract, peptone and dextrose), are likely to contain lipids, which may homogenize with the yeast lipids and play a role in masking the actual differences in the observed phenotypes or lead to an altered phenotype altogether. To address this issue, we compared the lipids of Candida albicans, our fungus of interest, grown in YPD or in a defined media such as YNB (yeast nitrogen base). Mass spectrometry-based lipid analyses showed differences in the levels of phospholipids, including phosphatidylinositol, phosphatidylglycerol, lyso-phospholipids; sphingolipids, such as mannosyldiinositolphosphorylceramide; and sterols, such as ergostatetraenol. Significant differences were observed in 70 lipid species between the cells grown in the two media, but the two growth conditions did not affect the morphological characteristics of C. albicans. The lipid profiles of the YNB- and YPD-grown C. albicans cells did vary, but these differences did not influence their response to the majority of the tested agents. Rather, the observed differences could be attributed to the slow growth rate of the Candida cells in YNB compared to YPD. Notably, the altered lipid changes between the two media did impact the susceptibility to some drugs. This data provided evidence that changes in media can lead to certain lipid alterations, which may affect specific pathways but, in general, do not affect the majority of the phenotypic properties of C. albicans. It was determined that either YNB or YPD may be suitable for the growth and lipid analysis of C. albicans, depending upon the experimental requirements, but additional precautions are necessary when correlating the phenotypes with the lipids.

  16. An Assessment of Growth Media Enrichment on Lipid Metabolome and the Concurrent Phenotypic Properties of Candida albicans

    PubMed Central

    Khandelwal, Nitesh Kumar; Bhardwaj, Nitin; Jha, Jaykar; Prasad, Rajendra

    2014-01-01

    A critical question among the researchers working on fungal lipid biology is whether the use of an enriched growth medium can affect the lipid composition of a cell and, therefore, contribute to the observed phenotypes. One presumption is that enriched medias, such as YPD (yeast extract, peptone and dextrose), are likely to contain lipids, which may homogenize with the yeast lipids and play a role in masking the actual differences in the observed phenotypes or lead to an altered phenotype altogether. To address this issue, we compared the lipids of Candida albicans, our fungus of interest, grown in YPD or in a defined media such as YNB (yeast nitrogen base). Mass spectrometry-based lipid analyses showed differences in the levels of phospholipids, including phosphatidylinositol, phosphatidylglycerol, lyso-phospholipids; sphingolipids, such as mannosyldiinositolphosphorylceramide; and sterols, such as ergostatetraenol. Significant differences were observed in 70 lipid species between the cells grown in the two media, but the two growth conditions did not affect the morphological characteristics of C. albicans. The lipid profiles of the YNB- and YPD-grown C. albicans cells did vary, but these differences did not influence their response to the majority of the tested agents. Rather, the observed differences could be attributed to the slow growth rate of the Candida cells in YNB compared to YPD. Notably, the altered lipid changes between the two media did impact the susceptibility to some drugs. This data provided evidence that changes in media can lead to certain lipid alterations, which may affect specific pathways but, in general, do not affect the majority of the phenotypic properties of C. albicans. It was determined that either YNB or YPD may be suitable for the growth and lipid analysis of C. albicans, depending upon the experimental requirements, but additional precautions are necessary when correlating the phenotypes with the lipids. PMID:25423360

  17. Effect of licorice compounds licochalcone A, glabridin and glycyrrhizic acid on growth and virulence properties of Candida albicans.

    PubMed

    Messier, Céline; Grenier, Daniel

    2011-11-01

    Candida albicans is the predominant causal agent of candidiasis. Its ability to form hyphae and biofilm has been suggested to be key virulence factors. In this study, we investigated the effect of major licorice compounds licochalcone A, glabridin and glycyrrhizic acid on growth, biofilm formation and yeast-hyphal transition of C. albicans. The synergistic effect of licorice compounds with the antifungal drug nystatin was also evaluated. Minimal inhibitory concentrations (MICs) for C. albicans were determined using a microplate dilution assay. The synergistic effect with nystatin was determined similarly. The effect of licorice compounds on biofilm formation was evaluated using a microplate assay and crystal violet staining. The effect of licorice compounds on yeast-hyphal transition was determined by microscopic observation. The toxicity of licorice compounds towards oral epithelial cells was evaluated with an MTT assay. Glabridin and licochalcone A showed antifungal activity on C. albicans while glycyrrhizic acid had no effect. Complete growth inhibition occurred with sub-inhibitory concentrations of nystatin with either glabridin or licochalcone A. Biofilm formation was inhibited by 35-60% in the presence of licochalcone A (0.2 μg ml(-1)). A strong inhibitory effect (>80%) on hyphal formation was observed with licochalcone A or glabridin (100 μg ml(-1)). Glabridin and licochalcone A at high concentrations showed toxicity towards oral epithelial cells. In summary, glabridin and licochalcone A are potent antifungal agents and may act in synergy with nystatin to inhibit growth of C. albicans. Licochalcone A has a significant effect on biofilm formation, while both licochalcone A and glabridin prevented yeast-hyphal transition in C. albicans. These results suggest a therapeutic potential of licochalcone A and glabridin for C. albicans oral infections. © 2011 Blackwell Verlag GmbH.

  18. An antisense-based functional genomics approach for identification of genes critical for growth of Candida albicans.

    PubMed

    De Backer, M D; Nelissen, B; Logghe, M; Viaene, J; Loonen, I; Vandoninck, S; de Hoogt, R; Dewaele, S; Simons, F A; Verhasselt, P; Vanhoof, G; Contreras, R; Luyten, W H

    2001-03-01

    Converting the complete genome sequence of Candida albicans into meaningful biological information will require comprehensive screens for identifying functional classes of genes. Most systems described so far are not applicable to C. albicans because of its difficulty with mating, its diploid nature, and the lack of functional random insertional mutagenesis methods. We examined artificial gene suppression as a means to identify gene products critical for growth of this pathogen; these represent new antifungal drug targets. To achieve gene suppression we combined antisense RNA inhibition and promoter interference. After cloning antisense complementary DNA (cDNA) fragments under control of an inducible GAL1 promoter, we transferred the resulting libraries to C. albicans. Over 2,000 transformant colonies were screened for a promoter-induced diminished-growth phenotype. After recovery of the plasmids, sequence determination of their inserts revealed the messenger RNA (mRNA) they inhibited or the gene they disrupted. Eighty-six genes critical for growth were identified, 45 with unknown function. When used in high-throughput screening for antifungals, the crippled C. albicans strains generated in this study showed enhanced sensitivity to specific drugs.

  19. Calcium homeostasis is required for contact-dependent helical and sinusoidal tip growth in Candida albicans hyphae.

    PubMed

    Brand, Alexandra; Lee, Keunsook; Veses, Veronica; Gow, Neil A R

    2009-03-01

    Hyphae of the dimorphic fungus, Candida albicans, exhibit directional tip responses when grown in contact with surfaces. On hard surfaces or in liquid media, the trajectory of hyphal growth is typically linear, with tip re-orientation events limited to encounters with topographical features (thigmotropism). In contrast, when grown on semisolid surfaces, the tips of C. albicans hyphae grow in an oscillatory manner to form regular two-dimensional sinusoidal curves and three-dimensional helices. We show that, like thigmotropism, initiation of directional tip oscillation in C. albicans hyphae is severely attenuated when Ca2+ homeostasis is perturbed. Chelation of extracellular Ca2+ or deletion of the Ca2+ transporters that modulate cytosolic [Ca2+] (Mid1, Cch1 or Pmr1) did not affect hyphal length but curve formation was severely reduced in mid1Delta and cch1Delta and abolished in pmr1Delta. Sinusoidal hypha morphology was altered in the mid1Delta, chs3Delta and heterozygous pmr1Delta/PMR1 strains. Treatments that affect cell wall integrity, changes in surface mannosylation or the provision of additional carbon sources had significant but less pronounced effects on oscillatory growth. The induction of two- and three-dimensional sinusoidal growth in wild-type C. albicans hyphae is therefore the consequence of mechanisms that involve Ca2+ influx and signalling rather than gross changes in the cell wall architecture.

  20. Azole resistance in Candida albicans.

    PubMed

    Smith, K J; Warnock, D W; Kennedy, C T; Johnson, E M; Hopwood, V; Van Cutsem, J; Vanden Bossche, H

    1986-04-01

    An isolate of Candida albicans from a patient with chronic mucocutaneous candidosis who relapsed during ketoconazole treatment was compared with a number of other azole-sensitive and azole-resistant isolates by tests in vitro and in three animal models of vaginal or disseminated infection. In-vitro tests indicated that the isolate was cross-resistant to all imidazole and triazole antifungals tested. In the animal models, treatment with miconazole, ketoconazole, itraconazole or fluconazole failed to influence the infection.

  1. Antimicrobial effect of farnesol, a Candida albicans quorum sensing molecule, on Paracoccidioides brasiliensis growth and morphogenesis

    PubMed Central

    Derengowski, Lorena S; De-Souza-Silva, Calliandra; Braz, Shélida V; Mello-De-Sousa, Thiago M; Báo, Sônia N; Kyaw, Cynthia M; Silva-Pereira, Ildinete

    2009-01-01

    Background Farnesol is a sesquiterpene alcohol produced by many organisms, and also found in several essential oils. Its role as a quorum sensing molecule and as a virulence factor of Candida albicans has been well described. Studies revealed that farnesol affect the growth of a number of bacteria and fungi, pointing to a potential role as an antimicrobial agent. Methods Growth assays of Paracoccidioides brasiliensis cells incubated in the presence of different concentrations of farnesol were performed by measuring the optical density of the cultures. The viability of fungal cells was determined by MTT assay and by counting the colony forming units, after each farnesol treatment. The effects of farnesol on P. brasiliensis dimorphism were also evaluated by optical microscopy. The ultrastructural morphology of farnesol-treated P. brasiliensis yeast cells was evaluated by transmission and scanning electron microscopy. Results In this study, the effects of farnesol on Paracoccidioides brasiliensis growth and dimorphism were described. Concentrations of this isoprenoid ranging from 25 to 300 μM strongly inhibited P. brasiliensis growth. We have estimated that the MIC of farnesol for P. brasiliensis is 25 μM, while the MLC is around 30 μM. When employing levels which don't compromise cell viability (5 to 15 μM), it was shown that farnesol also affected the morphogenesis of this fungus. We observed about 60% of inhibition in hyphal development following P. brasiliensis yeast cells treatment with 15 μM of farnesol for 48 h. At these farnesol concentrations we also observed a significant hyphal shortening. Electron microscopy experiments showed that, despite of a remaining intact cell wall, P. brasiliensis cells treated with farnesol concentrations above 25 μM exhibited a fully cytoplasmic degeneration. Conclusion Our data indicate that farnesol acts as a potent antimicrobial agent against P. brasiliensis. The fungicide activity of farnesol against this pathogen is

  2. Comparative assessment of the effectiveness of different cleaning methods on the growth of Candida albicans over acrylic surface

    PubMed Central

    Gantait, Subhajit; Bhattacharyya, Jayanta; Das, Samiran; Biswas, Shibendu; Ghati, Amit; Ghosh, Soumitra; Goel, Preeti

    2016-01-01

    Context: This study evaluated the efficacy of denture adhesive, cleanser, chlorhexidine, and brushing against Candida albicans biofilm developed on an acrylic surface and predicted the most effective, simple, and inexpensive way to maintain denture health, thereby preventing denture stomatitis. Aims: To find the best possible method for maintaining denture hygiene. Settings and Design: This retrospective analysis was conducted in the Guru Nanak Institute of Dental Sciences and Research, Kolkata, and this in vitro study was designed to minimize denture stomatitis among denture wearing population. Subjects and Methods: Sixty acrylic discs of equal dimensions after exposure to C. albicans were treated for a duration of 24 h with denture adhesive, cleanser, 0.2% chlorhexidine individually, or in combinations simulating clinical conditions dividing in six groups, ten samples each (n = 10). Statistical Analysis Used: After treatment, colony count was evaluated and statistically analyzed by post hoc Tukey's test and Dunnett's test to determine the most effective way of prevention. Results: The statistical post hoc analysis (Tukey's test and Dunnett's test) showed high significance (P < 0.0001). The group treated with adhesive showed high fungal growth compared to the control group, whereas chlorhexidine showed high potency to prevent C. albicans, whereas adhesive increased the adhesion of C. albicans to acrylic surface. Conclusions: Denture adhesive increases the adherence of C. albicans to denture surface. Other cleaning chemicals such as cleanser and chlorhexidine decrease the adherence. Moreover, among the all denture cleaning protocol, chlorhexidine drastically inhibit the adherence, as well as growth of C. albicans over denture surface. PMID:27630498

  3. A Trypsin Inhibitor from Tecoma stans Leaves Inhibits Growth and Promotes ATP Depletion and Lipid Peroxidation in Candida albicans and Candida krusei

    PubMed Central

    Patriota, Leydianne L. S.; Procópio, Thamara F.; de Souza, Maria F. D.; de Oliveira, Ana Patrícia S.; Carvalho, Lidiane V. N.; Pitta, Maira G. R.; Rego, Moacyr J. B. M.; Paiva, Patrícia M. G.; Pontual, Emmanuel V.; Napoleão, Thiago H.

    2016-01-01

    Tecoma stans (yellow elder) has shown medicinal properties and antimicrobial activity. Previous reports on antifungal activity of T. stans preparations and presence of trypsin inhibitor activity from T. stans leaves stimulated the investigation reported here. In this work, we proceeded to the purification and characterization of a trypsin inhibitor (TesTI), which was investigated for anti-Candida activity. Finally, in order to determine the potential of TesTI as a new natural chemotherapeutic product, its cytotoxicity to human peripheral blood mononuclear cells (PBMCs) was evaluated. TesTI was isolated from saline extract by ammonium sulfate fractionation followed by ion exchange and gel filtration chromatographies. Antifungal activity was evaluated by determining the minimal inhibitory (MIC) and fungicide (MFC) concentrations using fungal cultures containing only yeast form or both yeast and hyphal forms. Candida cells treated with TesTI were evaluated for intracellular ATP levels and lipid peroxidation. Cytotoxicity of TesTI to PBMCs was evaluated by MTT assay. TesTI (39.8 kDa, pI 3.41, Ki 43 nM) inhibited similarly the growth of both C. albicans and C. krusei culture types at MIC of 100 μg/mL. The MFCs were 200 μg/mL for C. albicans and C. krusei. Time-response curves revealed that TesTI (at MIC) was more effective at inhibiting the replication of C. albicans cells. At MIC, TesTI promoted reduction of ATP levels and lipid peroxidation in the Candida cells, being not cytotoxic to PBMCs. In conclusion, TesTI is an antifungal agent against C. albicans and C. krusei, without toxicity to human cells. PMID:27199940

  4. Paradoxical growth of Candida albicans in the presence of caspofungin is associated with multiple cell wall rearrangements and decreased virulence.

    PubMed

    Rueda, Cristina; Cuenca-Estrella, Manuel; Zaragoza, Oscar

    2014-01-01

    In the last decade, echinocandins have emerged as an important family of antifungal drugs because of their fungicidal activity against Candida spp. Echinocandins inhibit the enzyme β-1,3-d-glucan synthase, encoded by the FKS genes, and resistance to echinocandins is associated with mutations in this gene. In addition, echinocandin exposure can produce paradoxical growth, defined as the ability to grow at high antifungal concentrations but not at intermediate concentrations. In this work, we have demonstrated that paradoxical growth of Candida albicans in the presence of caspofungin is not due to antifungal degradation or instability. Media with high caspofungin concentrations recovered from wells where C. albicans showed paradoxical growth inhibited the growth of a Candida krusei reference strain. Cells exhibiting paradoxical growth at high caspofungin concentrations showed morphological changes such as enlarged size, abnormal septa, and absence of filamentation. Chitin content increased from the MIC to high caspofungin concentrations. Despite the high chitin levels, around 23% of cells died after treatment with caspofungin, indicating that chitin is required but not sufficient to protect the cells from the fungicidal effect of caspofungin. Moreover, we found that after paradoxical growth, β-1,3-glucan was exposed at the cell wall surface. Cells grown at high caspofungin concentrations had decreased virulence in the invertebrate host Galleria mellonella. Cells grown at high caspofungin concentrations also induced a proinflammatory response in murine macrophages compared to control cells. Our work highlights important aspects about fungal adaptation to caspofungin, and although this adaptation is associated with reduced virulence, the clinical implications remain to be elucidated.

  5. Characterization of Mucosal Candida albicans Biofilms

    PubMed Central

    Dongari-Bagtzoglou, Anna; Kashleva, Helena; Dwivedi, Prabhat; Diaz, Patricia; Vasilakos, John

    2009-01-01

    C. albicans triggers recurrent infections of the alimentary tract mucosa that result from biofilm growth. Although the ability of C. albicans to form a biofilm on abiotic surfaces has been well documented in recent years, no information exists on biofilms that form directly on mucosal surfaces. The objectives of this study were to characterize the structure and composition of Candida biofilms forming on the oral mucosa. We found that oral Candida biofilms consist of yeast, hyphae, and commensal bacteria, with keratin dispersed in the intercellular spaces. Neutrophils migrate through the oral mucosa and form nests within the biofilm mass. The cell wall polysaccharide β-glucan is exposed during mucosal biofilm growth and is more uniformly present on the surface of biofilm organisms invading the oral mucosa. We conclude that C. albicans forms complex mucosal biofilms consisting of both commensal bacterial flora and host components. These discoveries are important since they can prompt a shift of focus for current research in investigating the role of Candida-bacterial interactions in the pathogenesis of mucosal infections as well as the role of β-glucan mediated signaling in the host response. PMID:19956771

  6. Candida albicans Biofilms and Human Disease

    PubMed Central

    Nobile, Clarissa J.; Johnson, Alexander D.

    2016-01-01

    In humans, microbial cells (including bacteria, archaea, and fungi) greatly outnumber host cells. Candida albicans is the most prevalent fungal species of the human microbiota; this species asymptomatically colonizes many areas of the body, particularly the gastrointestinal and genitourinary tracts of healthy individuals. Alterations in host immunity, stress, resident microbiota, and other factors can lead to C. albicans overgrowth, causing a wide range of infections, from superficial mucosal to hematogenously disseminated candidiasis. To date, most studies of C. albicans have been carried out in suspension cultures; however, the medical impact of C. albicans (like that of many other microorganisms) depends on its ability to thrive as a biofilm, a closely packed community of cells. Biofilms are notorious for forming on implanted medical devices, including catheters, pacemakers, dentures, and prosthetic joints, which provide a surface and sanctuary for biofilm growth. C. albicans biofilms are intrinsically resistant to conventional antifungal therapeutics, the host immune system, and other environmental perturbations, making biofilm-based infections a significant clinical challenge. Here, we review our current knowledge of biofilms formed by C. albicans and closely related fungal species. PMID:26488273

  7. Effect of aqueous extract of miswak on the in vitro growth of Candida albicans.

    PubMed

    al-Bagieh, N H; Idowu, A; Salako, N O

    1994-01-01

    Chewing sticks (miswak) which are the roots of Salvadora persica plant have been used for centuries as oral hygiene tools in many parts of the world particularly in Saudi Arabia. Many studies have demonstrated the antiplaque, antiperiopathic, anticaries and antibacterial effect of these sticks. This study was designed to investigate the antimycotic effect, if any, of the aqueous extract of the plant roots. Various concentrations of aqueous extract of miswak prepared with Sabouraud medium were inoculated with Candida albicans (oral isolate). These were incubated at 37 degrees C and the turbidity was determined by OD at 600 nm wavelength measured at specific intervals over a period of 48 h. Data show that the extract at a concentration of 15% and above, has a fungistatic effect for up to 48 h. This antimycotic effect was probably due to one or more of the root contents which included chlorine, trimethylamine, and alkaloid resin, and sulphur compounds.

  8. Rapid screening method for compounds that affect the growth and germination of Candida albicans, using a real-time PCR thermocycler.

    PubMed

    Jarosz, Lucja M; Krom, Bastiaan P

    2011-11-01

    We propose a screening method for compounds affecting growth and germination in Candida albicans using a real-time PCR thermocycler to quantify green fluorescent protein (GFP) fluorescence. Using P(ACT1)-GFP and P(HWP1)-GFP reporter strains, the effects of a wide range of compounds on growth and hyphal formation were quantitatively assessed within 3 h after inoculation.

  9. Robust Extracellular pH Modulation by Candida albicans during Growth in Carboxylic Acids

    PubMed Central

    Danhof, Heather A.; Vylkova, Slavena; Vesely, Elisa M.; Ford, Amy E.; Gonzalez-Garay, Manuel

    2016-01-01

    ABSTRACT The opportunistic fungal pathogen Candida albicans thrives within diverse niches in the mammalian host. Among the adaptations that underlie this fitness is an ability to utilize a wide array of nutrients, especially sources of carbon that are disfavored by many other fungi; this contributes to its ability to survive interactions with the phagocytes that serve as key barriers against disseminated infections. We have reported that C. albicans generates ammonia as a byproduct of amino acid catabolism to neutralize the acidic phagolysosome and promote hyphal morphogenesis in a manner dependent on the Stp2 transcription factor. Here, we report that this species rapidly neutralizes acidic environments when utilizing carboxylic acids like pyruvate, α-ketoglutarate (αKG), or lactate as the primary carbon source. Unlike in cells growing in amino acid-rich medium, this does not result in ammonia release, does not induce hyphal differentiation, and is genetically distinct. While transcript profiling revealed significant similarities in gene expression in cells grown on either carboxylic or amino acids, genetic screens for mutants that fail to neutralize αKG medium identified a nonoverlapping set of genes, including CWT1, encoding a transcription factor responsive to cell wall and nitrosative stresses. Strains lacking CWT1 exhibit retarded αKG-mediated neutralization in vitro, exist in a more acidic phagolysosome, and are more susceptible to macrophage killing, while double cwt1Δ stp2Δ mutants are more impaired than either single mutant. Together, our observations indicate that C. albicans has evolved multiple ways to modulate the pH of host-relevant environments to promote its fitness as a pathogen. PMID:27935835

  10. Candida albicans commensalism in the gastrointestinal tract.

    PubMed

    Neville, B Anne; d'Enfert, Christophe; Bougnoux, Marie-Elisabeth

    2015-11-01

    Candida albicans is a polymorphic yeast species that often forms part of the commensal gastrointestinal mycobiota of healthy humans. It is also an important opportunistic pathogen. A tripartite interaction involving C. albicans, the resident microbiota and host immunity maintains C. albicans in its commensal form. The influence of each of these factors on C. albicans carriage is considered herein, with particular focus on the mycobiota and the approaches used to study it, models of gastrointestinal colonization by C. albicans, the C. albicans genes and phenotypes that are necessary for commensalism and the host factors that influence C. albicans carriage.

  11. Effect of Tetrandrine against Candida albicans Biofilms

    PubMed Central

    Zhao, Lan-Xue; Li, De-Dong; Hu, Dan-Dan; Hu, Gan-Hai; Yan, Lan; Wang, Yan; Jiang, Yuan-Ying

    2013-01-01

    Candida albicans is the most common human fungal pathogen and has a high propensity to develop biofilms that are resistant to traditional antifungal agents. In this study, we investigated the effect of tetrandrine (TET) on growth, biofilm formation and yeast-to-hypha transition of C. albicans. We characterized the inhibitory effect of TET on hyphal growth and addressed its possible mechanism of action. Treatment of TET at a low concentration without affecting fungal growth inhibited hyphal growth in both liquid and solid Spider media. Real-time RT-PCR revealed that TET down-regulated the expression of hypha-specific genes ECE1, ALS3 and HWP1, and abrogated the induction of EFG1 and RAS1, regulators of hyphal growth. Addition of cAMP restored the normal phenotype of the SC5314 strain. These results indicate that TET may inhibit hyphal growth through the Ras1p-cAMP-PKA pathway. In vivo, at a range of concentrations from 4 mg/L to 32 mg/L, TET prolonged the survival of C. albicans-infected Caenorhabditis elegans significantly. This study provides useful information for the development of new strategies to reduce the incidence of C. albicans biofilm-associated infections. PMID:24260276

  12. Cdc24, the GDP-GTP exchange factor for Cdc42, is required for invasive hyphal growth of Candida albicans.

    PubMed

    Bassilana, Martine; Blyth, James; Arkowitz, Robert A

    2003-02-01

    Candida albicans, the most common human fungal pathogen, is particularly problematic for immunocompromised individuals. The reversible transition of this fungal pathogen to a filamentous form that invades host tissue is important for its virulence. Although different signaling pathways such as a mitogen-activated protein kinase and a protein kinase A cascade are critical for this morphological transition, the function of polarity establishment proteins in this process has not been determined. We examined the role of four different polarity establishment proteins in C. albicans invasive growth and virulence by using strains in which one copy of each gene was deleted and the other copy expressed behind the regulatable promoter MET3. Strikingly, mutants with ectopic expression of either the Rho G-protein Cdc42 or its exchange factor Cdc24 are unable to form invasive hyphal filaments and germ tubes in response to serum or elevated temperature and yet grow normally as a budding yeast. Furthermore, these mutants are avirulent in a mouse model for systemic infection. This function of the Cdc42 GTPase module is not simply a general feature of polarity establishment proteins. Mutants with ectopic expression of the SH3 domain containing protein Bem1 or the Ras-like G-protein Bud1 can grow in an invasive fashion and are virulent in mice, albeit with reduced efficiency. These results indicate that a specific regulation of Cdc24/Cdc42 activity is required for invasive hyphal growth and suggest that these proteins are required for pathogenicity of C. albicans.

  13. Urinary tract infections and Candida albicans

    PubMed Central

    Behzadi, Payam; Behzadi, Elham

    2015-01-01

    Introduction Urinary tract candidiasis is known as the most frequent nosocomial fungal infection worldwide. Candida albicans is the most common cause of nosocomial fungal urinary tract infections; however, a rapid change in the distribution of Candida species is undergoing. Simultaneously, the increase of urinary tract candidiasis has led to the appearance of antifungal resistant Candida species. In this review, we have an in depth look into Candida albicans uropathogenesis and distribution of the three most frequent Candida species contributing to urinary tract candidiasis in different countries around the world. Material and methods For writing this review, Google Scholar –a scholarly search engine– (http://scholar.google.com/) and PubMed database (http://www.ncbi.nlm.nih.gov/pubmed/) were used. The most recently published original articles and reviews of literature relating to the first three Candida species causing urinary tract infections in different countries and the pathogenicity of Candida albicans were selected and studied. Results Although some studies show rapid changes in the uropathogenesis of Candida species causing urinary tract infections in some countries, Candida albicans is still the most important cause of candidal urinary tract infections. Conclusions Despite the ranking of Candida albicans as the dominant species for urinary tract candidiasis, specific changes have occurred in some countries. At this time, it is important to continue the surveillance related to Candida species causing urinary tract infections to prevent, control and treat urinary tract candidiasis in future. PMID:25914847

  14. Adherence and receptor relationships of Candida albicans.

    PubMed Central

    Calderone, R A; Braun, P C

    1991-01-01

    The cell surface of Candida albicans is composed of a variety of polysaccharides such as glucan, chitin, and mannan. The first two components primarily provide structure, while the mannan, often covalently linked to protein, constitutes the major antigen of the organism. Mannoproteins also have enzymatic activity (acid protease) and ligand-receptor functions. The complement receptors of C. albicans appear to be mannoproteins that are required for the adherence of the organism to endothelial cells. This is certainly true of the CR3-like protein of C. albicans. Proof that the CR3 is the Candida receptor for endothelial cells is derived from two observations. First, mutants lacking CR3 activity are less adherent in vitro and, in fact, less virulent. Second, the ligand recognized by the CR3 receptor (C3bi) as well as anti-CR3 antibodies blocks adherence of the organism to endothelial cells. The CR2 of C. albicans appears to promote the adherence of the organism to plastic substrates. Unlike the CR2 of mammalian cells, the Candida CR2 recognizes ligands containing the RGD sequence of amino acids in addition to the C3d ligand, which does not contain the RGD sequence. There is uncertainty as to whether the Candida CR2 and CR3 are, in fact, different proteins. A mannoprotein has also been described as the adhesin for epithelial cells. In this case, the receptor has a lectinlike activity and recognizes fucose- or glucosamine-containing glycoproteins of epithelial cells, depending on the strain of C. albicans. The oligosaccharide component of the receptor is probably not involved in ligand recognition and may serve to stabilize the receptor. However, the oligosaccharide factor 6 epitope of mannan may also provide adhesin activity in the recognition of epithelial cells. Mannoproteins can be extracted from cells by a number of reagents. Zymolyase, for instance, tends to remove structural mannoproteins, which contain relatively little protein and are linked to glucan. Reagents

  15. Resveratrol lacks antifungal activity against Candida albicans.

    PubMed

    Collado-González, Mar; Guirao-Abad, José P; Sánchez-Fresneda, Ruth; Belchí-Navarro, Sarai; Argüelles, Juan-Carlos

    2012-06-01

    The putative candicidal activity of resveratrol is currently a matter of controversy. Here, the antifungal activity as well as the antioxidant response of resveratrol against Candida albicans, have been tested in a set of strains with a well-established genetic background At the doses usually employed in antifungal tests (10-40 μg/ml), resveratrol has no effect on the exponential growth of the C. albicans CAI.4 strain, a tenfold increase (400 μg/ml) was required in order to record a certain degree of cell killing, which was negligible in comparison with the strong antifungal effect caused by the addition of amphotericin B (5 μg/ml). An identical pattern was recorded in the prototrophic strains of C. albicans SC5314 and RM-100, whereas the oxidative sensitive trehalose-deficient mutant (tps1/tps1 strain) was totally refractory to the presence of resveratrol. In turn, the serum-induced yeast-to-hypha transition remained unaffected upon addition of different concentrations of resveratrol. Determination of endogenous trehalose and catalase activity, two antioxidant markers in C. albicans; revealed no significant changes in their basal contents induced by resveratrol. Collectively, our results seem to dismiss a main antifungal role as well as the therapeutic application of resveratrol against the infections caused by C. albicans.

  16. Cell cycle arrest during S or M phase generates polarized growth via distinct signals in Candida albicans.

    PubMed

    Bachewich, Catherine; Nantel, Andre; Whiteway, Malcolm

    2005-08-01

    Treatments that perturb DNA synthesis or mitosis will activate checkpoints that prevent cell cycle progression and cell proliferation. In yeast-form cells of the fungal pathogen Candida albicans, exposure to hydroxyurea (HU) or shutting off expression of the polo-like kinase CaCDC5 blocked nuclear division and spindle elongation, but activated a highly polarized growth mode. We have used transcription profiling both to characterize the initiation and progression of this polar growth pattern and to determine how cell elongation may be linked to the cell cycle in C. albicans. Different gene expression patterns during early stages of cell elongation support the concept that CaCdc5p-depleted and HU-exposed cells were blocked at different stages of the cell cycle, and suggest that different signals may generate the common polarized growth phenotype. Consistent with this, BUB2 expression was modulated in CaCdc5p-depleted cells, and absence of BUB2 prevented the maintenance of cell polarization, resulting in multibudded, pseudohyphal cells with constrictions. In contrast, HU-induced filaments did not modulate or require BUB2, but were dependent on the GTPase Ras1p. However, at later stages of cell elongation, transcription profiles were more similar, and comparisons with serum-induced hyphae revealed that the cell cycle-arrested filaments expressed several targets of the hyphal signalling pathways. Thus, arresting the yeast cell cycle in S or M phase generates a polarized growth pattern through different mechanisms in C. albicans, and maintenance of the polar growth mode can ultimately lead to the expression of hyphal-associated cell wall and virulence-related factors, in the absence of any external stimuli.

  17. Human Serum Promotes Candida albicans Biofilm Growth and Virulence Gene Expression on Silicone Biomaterial

    PubMed Central

    Samaranayake, Yuthika Hemamala; Cheung, Becky P. K.; Yau, Joyce Y. Y.; Yeung, Shadow K. W.; Samaranayake, Lakshman P.

    2013-01-01

    Objectives Systemic candidal infections are a common problem in hospitalized patients due to central venous catheters fabricated using silicone biomaterial (SB). We therefore evaluated the effect of human serum on C. albicans biofilm morphology, growth, and the expression of virulence-related genes on SB in vitro. Methods We cultivated C. albicans SC5314 (wild-type strain, WT) and its derivative HLC54 (hyphal mutant, HM) for 48 h in various conditions, including the presence or absence of SB discs, and human serum. The growth of planktonic and biofilm cells of both strains was monitored at three time points by a tetrazolium salt reduction assay and by scanning electron microscopy. We also analyzed by RT-PCR its expression of the virulence-related genes ALS3, HWP1, EAP1, ECE1, SAP1 - SAP10, PLB1, PLB2, PLC and PLD. Results At each time point, planktonic cells of WT strain cultured in yeast nitrogen base displayed a much higher expression of EAP1 and HWP1, and a moderately higher ALS3 expression, than HM cells. In planktonic cells, expression of the ten SAP genes was higher in the WT strain initially, but were highly expressed in the HM strain by 48 h. Biofilm growth of both strains on SB was promoted in the presence of human serum than in its absence. Significant upregulation of ALS3, HWP1, EAP1, ECE1, SAP1, SAP4, SAP6 - SAP10, PLB1, PLB2 and PLC was observed for WT biofilms grown on serum-treated SB discs for at least one time point, compared with biofilms on serum-free SB discs. Conclusions Human serum stimulates C. albicans biofilm growth on SB discs and upregulates the expression of virulence genes, particularly adhesion genes ALS3 and HWP1, and hydrolase-encoding genes SAP, PLB1 and PLB2. This response is likely to promote the colonization of this versatile pathogen within the human host. PMID:23704884

  18. Sep7 Is Essential to Modify Septin Ring Dynamics and Inhibit Cell Separation during Candida albicans Hyphal Growth

    PubMed Central

    González-Novo, Alberto; Correa-Bordes, Jaime; Labrador, Leticia; Sánchez, Miguel

    2008-01-01

    When Candida albicans yeast cells receive the appropriate stimulus, they switch to hyphal growth, characterized by continuous apical elongation and the inhibition of cell separation. The molecular basis of this inhibition is poorly known, despite its crucial importance for hyphal development. In C. albicans, septins are important for hypha formation and virulence. Here, we used fluorescence recovery after photobleaching analysis to characterize the dynamics of septin rings during yeast and hyphal growth. On hyphal induction, septin rings are converted to a hyphal-specific state, characterized by the presence of a frozen core formed by Sep7/Shs1, Cdc3 and Cdc12, whereas Cdc10 is highly dynamic and oscillates between the ring and the cytoplasm. Conversion of septin rings to the hyphal-specific state inhibits the translocation of Cdc14 phosphatase, which controls cell separation, to the hyphal septum. Modification of septin ring dynamics during hyphal growth is dependent on Sep7 and the hyphal-specific cyclin Hgc1, which partially controls Sep7 phosphorylation status and protein levels. Our results reveal a link between the cell cycle machinery and septin cytoskeleton dynamics, which inhibits cell separation in the filaments and is essential for hyphal morphogenesis. PMID:18234840

  19. Screening of metabolites secondary compounds in extract of moringa fruit and determination of inhibitory effect on growth of the fungus Candida albicans

    NASA Astrophysics Data System (ADS)

    Nuryanti, Siti; Puspitasari, Dwi Juli

    2017-08-01

    Moringa (Moringa oleifera Lamk) is a nutritious plant that can cure various diseases. Parts of this plant like leave, root, flower, and fruit can be used as a traditional medicine. The research about screening of secondary metabolites in moringa extracts and the determination of their inhibitory effect on growth of the fungus Candida albicans have been done. This research was conducted by extracting the moringa fruit with various solvent with different polarity namely hexane, distilled water and ethanol. The fungal inhibition test was done by well-difuse method. Suspensions of Candida albicans was standardized by 0.5 Mc Farland standard. The results showed that the extracts of Moringa with distilled water provided the greatest inhibition on the growth of the fungus Candida albicans compared to moringa fruit extracted by ethanol and hexane. The percentages inhibition of Moringa extracts on the growth of the Candida albicans with distilled water, ethanol and hexane solvents were 89.90%, 57.90% and 8.97% respectively. Phytochemical screening test showed that the moringa fruit contain alkaloids, flavonoids and steroids.

  20. Relationship between cell surface composition of Candida albicans and adherence to acrylic after growth on different carbon sources.

    PubMed Central

    McCourtie, J; Douglas, L J

    1981-01-01

    The adherence of Candida albicans to acrylic was measured in vitro after growth of the yeast to stationary phase in defined medium containing glucose, sucrose, galactose, fructose, or maltose as the carbon source. In each case, yeast adherence was proportional to the concentration of sugar in the growth medium, but equimolar concentrations of different sugars promoted adherence to different extents. In vitro adherence was further increased by the addition of divalent cations to assay mixtures but was inhibited when saliva-treated acrylic strips were used or when yeasts were suspended in mixed saliva during the assay. The rate of spheroplast formation of yeasts grown in media containing a 500 mM concentration of the different sugars correlated well with the relative adherence of the cells to acrylic. Galactose-grown yeasts were most resistant to spheroplast formation with Zymolyase-5000 and most adherent to acrylic, whereas fructose-grown organisms were least resistant to spheroplast formation and least adherent to acrylic. These results indicate that when grown to stationary phase in media containing high concentrations of certain sugars, C. albicans undergoes a change in cell surface composition which facilitates its adherence to acrylic surfaces. Electron microscopy of yeasts harvested from such media revealed the presence of an additional surface layer which may be responsible for this enhanced adherence. Images PMID:7019091

  1. Beyond Candida albicans: Mechanisms of immunity to non-albicans Candida species.

    PubMed

    Whibley, Natasha; Gaffen, Sarah L

    2015-11-01

    The fungal genus Candida encompasses numerous species that inhabit a variety of hosts, either as commensal microbes and/or pathogens. Candida species are a major cause of fungal infections, yet to date there are no vaccines against Candida or indeed any other fungal pathogen. Our knowledge of immunity to Candida mainly comes from studies on Candida albicans, the most frequent species associated with disease. However, non-albicans Candida (NAC) species also cause disease and their prevalence is increasing. Although research into immunity to NAC species is still at an early stage, it is becoming apparent that immunity to C. albicans differs in important ways from non-albicans species, with important implications for treatment, therapy and predicted demographic susceptibility. This review will discuss the current understanding of immunity to NAC species in the context of immunity to C. albicans, and highlight as-yet unanswered questions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. The Sur7 Protein Regulates Plasma Membrane Organization and Prevents Intracellular Cell Wall Growth in Candida albicans

    PubMed Central

    Alvarez, Francisco J.; Douglas, Lois M.; Rosebrock, Adam

    2008-01-01

    The Candida albicans plasma membrane plays important roles in cell growth and as a target for antifungal drugs. Analysis of Ca-Sur7 showed that this four transmembrane domain protein localized to stable punctate patches, similar to the plasma membrane subdomains known as eisosomes or MCC that were discovered in S. cerevisiae. The localization of Ca-Sur7 depended on sphingolipid synthesis. In contrast to S. cerevisiae, a C. albicans sur7Δ mutant displayed defects in endocytosis and morphogenesis. Septins and actin were mislocalized, and cell wall synthesis was very abnormal, including long projections of cell wall into the cytoplasm. Several phenotypes of the sur7Δ mutant are similar to the effects of inhibiting β-glucan synthase, suggesting that the abnormal cell wall synthesis is related to activation of chitin synthase activity seen under stress conditions. These results expand the roles of eisosomes by demonstrating that Sur7 is needed for proper plasma membrane organization and cell wall synthesis. A conserved Cys motif in the first extracellular loop of fungal Sur7 proteins is similar to a characteristic motif of the claudin proteins that form tight junctions in animal cells, suggesting a common role for these tetraspanning membrane proteins in forming specialized plasma membrane domains. PMID:18799621

  3. Regulation of phenotypic transitions in the fungal pathogen Candida albicans

    PubMed Central

    Huang, Guanghua

    2012-01-01

    The human commensal fungus Candida albicans can cause not only superficial infections, but also life-threatening disease in immunocompromised individuals. C. albicans can grow in several morphological forms. The ability to switch between different phenotypic forms has been thought to contribute to its virulence. The yeast-filamentous growth transition and white-opaque switching represent two typical morphological switching systems, which have been intensively studied in C. albicans. The interplay between environmental factors and genes determines the morphology of C. albicans. This review focuses on the regulation of phenotypic changes in this pathogenic organism by external environmental cues and internal genes. PMID:22546903

  4. Candida/Candida biofilms. First description of dual-species Candida albicans/C. rugosa biofilm.

    PubMed

    Martins, Carlos Henrique Gomes; Pires, Regina Helena; Cunha, Aline Oliveira; Pereira, Cristiane Aparecida Martins; Singulani, Junya de Lacorte; Abrão, Fariza; Moraes, Thais de; Mendes-Giannini, Maria José Soares

    2016-04-01

    Denture liners have physical properties that favour plaque accumulation and colonization by Candida species, irritating oral tissues and causing denture stomatitis. To isolate and determine the incidence of oral Candida species in dental prostheses, oral swabs were collected from the dental prostheses of 66 patients. All the strains were screened for their ability to form biofilms; both monospecies and dual-species combinations were tested. Candida albicans (63 %) was the most frequently isolated microorganism; Candida tropicalis (14 %), Candida glabrata (13 %), Candida rugosa (5 %), Candida parapsilosis (3 %), and Candida krusei (2 %) were also detected. The XTT assay showed that C. albicans SC5314 possessed a biofilm-forming ability significantly higher (p < 0.001) than non-albicans Candida strains, after 6 h 37 °C. The total C. albicans CFU from a dual-species biofilm was less than the total CFU of a monospecies C. albicans biofilm. In contrast to the profuse hyphae verified in monospecies C. albicans biofilms, micrographies showed that the C. albicans/non-albicans Candida biofilms consisted of sparse yeast forms and profuse budding yeast cells that generated a network. These results suggested that C. albicans and the tested Candida species could co-exist in biofilms displaying apparent antagonism. The study provide the first description of C. albicans/C. rugosa mixed biofilm.

  5. Beyond Candida albicans: Mechanisms of immunity to non-albicans Candida species

    PubMed Central

    Whibley, Natasha; Gaffen, Sarah L.

    2015-01-01

    The fungal genus Candida encompasses numerous species that inhabit a variety of hosts, either as commensal microbes and/or pathogens. Candida species are a major cause of fungal infections, yet to date there are no vaccines against Candida or indeed any other fungal pathogen. Our knowledge of immunity to Candida mainly comes from studies on C. albicans, the most frequent species associated with disease. However, non-albicans Candida (NAC) species also cause disease and their prevalence is increasing. Although research into immunity to NAC species is still at an early stage, it is becoming apparent that immunity to C. albicans differs in important ways from non-albicans species, with important implications for treatment, therapy and predicted demographic susceptibility. This review will discuss the current understanding of immunity to NAC species in the context of immunity to C. albicans, and highlight as-yet unanswered questions. PMID:26276374

  6. Effect of Streptococcus salivarius K12 on the in vitro growth of Candida albicans and its protective effect in an oral candidiasis model.

    PubMed

    Ishijima, Sanae A; Hayama, Kazumi; Burton, Jeremy P; Reid, Gregor; Okada, Masashi; Matsushita, Yuji; Abe, Shigeru

    2012-04-01

    Oral candidiasis is often accompanied by severe inflammation, resulting in a decline in the quality of life of immunosuppressed individuals and elderly people. To develop a new oral therapeutic option for candidiasis, a nonpathogenic commensal oral probiotic microorganism, Streptococcus salivarius K12, was evaluated for its ability to modulate Candida albicans growth in vitro, and its therapeutic activity in an experimental oral candidiasis model was tested. In vitro inhibition of mycelial growth of C. albicans was determined by plate assay and fluorescence microscopy. Addition of S. salivarius K12 to modified RPMI 1640 culture medium inhibited the adherence of C. albicans to the plastic petri dish in a dose-dependent manner. Preculture of S. salivarius K12 potentiated its inhibitory activity for adherence of C. albicans. Interestingly, S. salivarius K12 was not directly fungicidal but appeared to inhibit Candida adhesion to the substratum by preferentially binding to hyphae rather than yeast. To determine the potentially anti-infective attributes of S. salivarius K12 in oral candidiasis, the probiotic was administered to mice with orally induced candidiasis. Oral treatment with S. salivarius K12 significantly protected the mice from severe candidiasis. These findings suggest that S. salivarius K12 may inhibit the process of invasion of C. albicans into mucous surfaces or its adhesion to denture acrylic resins by mechanisms not associated with the antimicrobial activity of the bacteriocin. S. salivarius K12 may be useful as a probiotic as a protective tool for oral care, especially with regard to candidiasis.

  7. Effect of Streptococcus salivarius K12 on the In Vitro Growth of Candida albicans and Its Protective Effect in an Oral Candidiasis Model

    PubMed Central

    Hayama, Kazumi; Burton, Jeremy P.; Reid, Gregor; Okada, Masashi; Matsushita, Yuji; Abe, Shigeru

    2012-01-01

    Oral candidiasis is often accompanied by severe inflammation, resulting in a decline in the quality of life of immunosuppressed individuals and elderly people. To develop a new oral therapeutic option for candidiasis, a nonpathogenic commensal oral probiotic microorganism, Streptococcus salivarius K12, was evaluated for its ability to modulate Candida albicans growth in vitro, and its therapeutic activity in an experimental oral candidiasis model was tested. In vitro inhibition of mycelial growth of C. albicans was determined by plate assay and fluorescence microscopy. Addition of S. salivarius K12 to modified RPMI 1640 culture medium inhibited the adherence of C. albicans to the plastic petri dish in a dose-dependent manner. Preculture of S. salivarius K12 potentiated its inhibitory activity for adherence of C. albicans. Interestingly, S. salivarius K12 was not directly fungicidal but appeared to inhibit Candida adhesion to the substratum by preferentially binding to hyphae rather than yeast. To determine the potentially anti-infective attributes of S. salivarius K12 in oral candidiasis, the probiotic was administered to mice with orally induced candidiasis. Oral treatment with S. salivarius K12 significantly protected the mice from severe candidiasis. These findings suggest that S. salivarius K12 may inhibit the process of invasion of C. albicans into mucous surfaces or its adhesion to denture acrylic resins by mechanisms not associated with the antimicrobial activity of the bacteriocin. S. salivarius K12 may be useful as a probiotic as a protective tool for oral care, especially with regard to candidiasis. PMID:22267663

  8. Plasticity of Candida albicans Biofilms

    PubMed Central

    Daniels, Karla J.

    2016-01-01

    SUMMARY Candida albicans, the most pervasive fungal pathogen that colonizes humans, forms biofilms that are architecturally complex. They consist of a basal yeast cell polylayer and an upper region of hyphae encapsulated in extracellular matrix. However, biofilms formed in vitro vary as a result of the different conditions employed in models, the methods used to assess biofilm formation, strain differences, and, in a most dramatic fashion, the configuration of the mating type locus (MTL). Therefore, integrating data from different studies can lead to problems of interpretation if such variability is not taken into account. Here we review the conditions and factors that cause biofilm variation, with the goal of engendering awareness that more attention must be paid to the strains employed, the methods used to assess biofilm development, every aspect of the model employed, and the configuration of the MTL locus. We end by posing a set of questions that may be asked in comparing the results of different studies and developing protocols for new ones. This review should engender the notion that not all biofilms are created equal. PMID:27250770

  9. The Candida albicans KRE9 gene is required for cell wall β-1,6-glucan synthesis and is essential for growth on glucose

    PubMed Central

    Lussier, Marc; Sdicu, Anne-Marie; Shahinian, Serge; Bussey, Howard

    1998-01-01

    We have isolated CaKRE9, a gene from Candida albicans, that is a functional homologue of the Saccharomyces cerevisiae KRE9 gene involved in β-1,6-glucan synthesis. Disruption of the CaKRE9 gene in C. albicans shows that CaKre9p is required for the synthesis or assembly of this fungal polymer. Homozygous null disruptants of CaKRE9 grow poorly on galactose and fail to form hyphae in serum, and, in growth medium containing glucose, the gene is essential. Thus, the CaKRE9 gene product is a potentially useful candidate as a target for fungal-specific drugs. PMID:9707560

  10. Rax2 is important for directional establishment of growth sites, but not for reorientation of growth axes, during Candida albicans hyphal morphogenesis.

    PubMed

    Gonia, Sara; Norton, Jennifer; Watanaskul, Lindy; Pulver, Rebecca; Morrison, Emma; Brand, Alexandra; Gale, Cheryl A

    2013-07-01

    Hyphae of filamentous fungi maintain generally linear growth over long distances. In Candida albicans, hyphae are able to reorient their growth in the direction of certain environmental cues. In previous work, the C. albicans bud-site selection proteins Rsr1 and Bud2 were identified as important for hyphae to maintain linear growth and were necessary for hyphal responses to directional cues in the environment (tropisms). To ask if hyphal directional responses are general functions of all yeast bud-site selection proteins, we studied the role of Rax2, ortholog of the Saccharomyces cerevisiae bud-site selection protein Rax2, in C. albicans hyphal morphogenesis. Rax2-YFP localized to the hyphal cell surface in puncta and at the hyphal tip in a crescent. Strains lacking Rax2 had hyphal morphologies that did not differ from control strains. In non-cued growth conditions, rax2 mutant strains had defects in both yeast (bud) and hyphal (branch) site selection and mutant hyphae exhibited non-linear growth trajectories as compared to control hyphae. In contrast, when encountering a directional environmental cue, hyphae lacking Rax2 retained the ability to reorient growth in response to both topographical (thigmotropism) and electric-field (galvanotropism) stimuli but exhibited a reduced ability to establish hyphal growth in the direction of a cathodal stimulus. In conclusion, these results indicate that C. albicans Rax2 is important for establishing sites of emergence of yeast and hyphal daughters and for maintaining the linearity of hyphal growth. In contrast to Rsr1 and Bud2, Rax2 is not involved in responses that require a reorientation of the direction of already established hyphal growth (tropisms). Thus, it appears that some hyphal directionality responses are separable in that they are mediated by a different set of polarity proteins. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. New synthetic sulfone derivatives inhibit growth, adhesion and the leucine arylamidase APE2 gene expression of Candida albicans in vitro.

    PubMed

    Staniszewska, Monika; Bondaryk, Małgorzata; Ochal, Zbigniew

    2015-01-15

    The successful preventing and effective treatment of invasive Candida albicans infections required research focused on synthesis of new classes of agents and antifungal activity studies. Bromodichloromethyl-4-chloro-3-nitrophenyl sulfone (named compound 6); dichloromethyl-4-chloro-3-nitrophenyl sulfone (named 7); and chlorodibromomethyl-4-hydrazino-3-nitrophenyl sulfone (named 11) on inhibition of planktonic cells' growth, leucine arylamidase APE2 gene expression, and adhesion to epithelial cells were investigated. In vitro anti-Candida activities were determined against wild-types, and the morphogenesis mutants: Δefg1 and Δcph1. MICs of compounds 6, 7 and 11 (concentrated at 0.25-16μg/ml) were determined using the Clinical and Laboratory Standards Institute Broth Microdilution Method (M27-A3 Document). APE2 expression was analyzed using RT-PCR; relative quantification was normalized against ACT1 in cells growth in YEPD and on Caco-2 cell line. Adherence assay of C. albicans to Caco-2 was performed in 24-well-plate. The structure activity relationship suggested that sulfone containing hydrazine function at C-1 (compound 11) showed higher antifungal activity (cell inhibition%=100 at 1-16μg/ml) than the remaining sulfones with chlorine at C-1. Δcph1/Δefg1 was highly sensitive to compound 11, while the sensitivity was reduced in Δcph1/Δefg1::EFG1 (%=100 at 16-fold higher concentration). Compound 11 significantly affected adherence to epithelium (P ⩽0.05) and hyphae formation. The APE2 up-regulation plays role in sulfones' resistance on MAP kinase pathway. Either CPH1 or EFG1 play a role in the resistance mechanism in sulfones. The strain-dependent phenomenon is a factor in the sulfone resistance mechanism. Sulfones' mode of action was attributed to reduced virulence arsenal in terms of adhesiveness and pathogenic potential related to the APE2 expression and morphogenesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Hbr1 Activates and Represses Hyphal Growth in Candida albicans and Regulates Fungal Morphogenesis under Embedded Conditions

    PubMed Central

    Pendrak, Michael L.; Roberts, David D.

    2015-01-01

    Transitions between yeast and hyphae are essential for Candida albicans pathogenesis. The genetic programs that regulate its hyphal development can be distinguished by embedded versus aerobic surface agar invasion. Hbr1, a regulator of white-opaque switching, is also a positive and negative regulator of hyphal invasion. During embedded growth at 24°C, an HBR1/hbr1 strain formed constitutively filamentous colonies throughout the matrix, resembling EFG1 null colonies, and a subset of long unbranched hyphal aggregates enclosed in a spindle-shaped capsule. Inhibition of adenylate cyclase with farnesol perturbed the filamentation of HBR1/hbr1 cells producing cytokinesis-defective hyphae whereas farnesol treated EFG1 null cells produced abundant opaque-like cells. Point mutations in the Hbr1 ATP-binding domain caused distinct filamentation phenotypes including uniform radial hyphae, hyphal sprouts, and massive yeast cell production. Conversely, aerobic surface colonies of the HBR1 heterozygote on Spider and GlcNAc media lacked filamentation that could be rescued by growth under low (5%) O2. Consistent with these morphogenesis defects, the HBR1 heterozygote exhibited attenuated virulence in a mouse candidemia model. These data define Hbr1 as an ATP-dependent positive and negative regulator of hyphal development that is sensitive to hypoxia. PMID:26039220

  13. Candida krusei and Candida glabrata reduce the filamentation of Candida albicans by downregulating expression of HWP1 gene.

    PubMed

    de Barros, Patrícia Pimentel; Freire, Fernanda; Rossoni, Rodnei Dennis; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso

    2017-07-01

    Pathogenicity of Candida albicans is associated with its capacity switch from yeast-like to hyphal growth. The hyphal form is capable to penetrate the epithelial surfaces and to damage the host tissues. Therefore, many investigations have focused on mechanisms that control the morphological transitions of C. albicans. Recently, certain studies have showed that non-albicans Candida species can reduce the capacity of C. albicans to form biofilms and to develop candidiasis in animal models. Then, the objective of this study was to evaluate the effects of Candida krusei and Candida glabrata on the morphogenesis of C. albicans. Firstly, the capacity of reference and clinical strains of C. albicans in forming hyphae was tested in vitro. After that, the expression of HWP1 (hyphal wall protein 1) gene was determined by quantitative real-time PCR (polymerase chain reaction) assay. For both reference and clinical strains, a significant inhibition of the hyphae formation was observed when C. albicans was incubated in the presence of C. krusei or C. glabrata compared to the control group composed only by C. albicans. In addition, the culture mixed of C. albicans-C. krusei or C. albicans-C. glabrata reduced significantly the expression of HWP1 gene of C. albicans in relation to single cultures of this specie. In both filamentation and gene expression assays, C. krusei showed the higher inhibitory activity on the morphogenesis of C. albicans compared to C. glabrata. C. krusei and C. glabrata are capable to reduce the filamentation of C. albicans and consequently decrease the expression of the HWP1 gene.

  14. Mucins suppress virulence traits of Candida albicans.

    PubMed

    Kavanaugh, Nicole L; Zhang, Angela Q; Nobile, Clarissa J; Johnson, Alexander D; Ribbeck, Katharina

    2014-11-11

    Candida albicans is the most prevalent fungal pathogen of humans, causing a variety of diseases ranging from superficial mucosal infections to deep-seated systemic invasions. Mucus, the gel that coats all wet epithelial surfaces, accommodates C. albicans as part of the normal microbiota, where C. albicans resides asymptomatically in healthy humans. Through a series of in vitro experiments combined with gene expression analysis, we show that mucin biopolymers, the main gel-forming constituents of mucus, induce a new oval-shaped morphology in C. albicans in which a range of genes related to adhesion, filamentation, and biofilm formation are downregulated. We also show that corresponding traits are suppressed, rendering C. albicans impaired in forming biofilms on a range of different synthetic surfaces and human epithelial cells. Our data suggest that mucins can manipulate C. albicans physiology, and we hypothesize that they are key environmental signals for retaining C. albicans in the host-compatible, commensal state. The yeast Candida albicans causes both superficial infections of the mucosa and life-threatening infections upon entering the bloodstream. However, C. albicans is not always harmful and can exist as part of the normal microbiota without causing disease. Internal body surfaces that are susceptible to infection by C. albicans are coated with mucus, which we hypothesize plays an important role in preventing infections. Here, we show that the main components of mucus, mucin glycoproteins, suppress virulence attributes of C. albicans at the levels of gene expression and the corresponding morphological traits. Specifically, mucins suppress attachment to plastic surfaces and human cells, the transition to cell-penetrating hyphae, and the formation of biofilms (drug-resistant microbial communities). Additionally, exposure to mucins induces an elongated morphology that physically resembles the mating-competent opaque state but is phenotypically distinct. We

  15. [Malignant otitis externa caused by Candida albicans].

    PubMed

    Elayoubi, Fahd; Lachkar, Azeddine; Aabach, Ahmed; Chouai, Mohamed; Ghailan, Mohamed Rachid

    2016-01-01

    Malignant otitis externa is also referred to as skull base osteomyelitis. Pseudomonas aeruginosa is the most common offending pathogen. However, fungal origin is not uncommon. 80-year-old patient having persistent left earache since two months despite adequate treatment. Otologic examination showed signs of inflammation in the auricular pavilion, ear canal stenosis with granulomas and purulent otorrhea. CT scan showed a filled otomastoid, extensive inflammatory process affecting the pre-auricular and retro-auricular tissues and lysis of the tympanic bulla. Given the lack of improvement, mycological examination was performed which revealed the presence of Candida Albicans. Cases of malignant otitis externa caused by Candida albicans are rarely reported. Fungal origin should be suspected in patients who have negative bacteriological samples and no improvement despite adequate antibiotic treatment. It should be confirmed by sometimes multiple mycological samples. Malignant otitis externa caused by Candida albicans is a rare potentially mortal infection.

  16. Adaptive immune responses to Candida albicans infection

    PubMed Central

    Richardson, Jonathan P; Moyes, David L

    2015-01-01

    Fungal infections are becoming increasingly prevalent in the human population and contribute to morbidity and mortality in healthy and immunocompromised individuals respectively. Candida albicans is the most commonly encountered fungal pathogen of humans, and is frequently found on the mucosal surfaces of the body. Host defense against C. albicans is dependent upon a finely tuned implementation of innate and adaptive immune responses, enabling the host to neutralise the invading fungus. Central to this protection are the adaptive Th1 and Th17 cellular responses, which are considered paramount to successful immune defense against C. albicans infections, and enable tissue homeostasis to be maintained in the presence of colonising fungi. This review will highlight the recent advances in our understanding of adaptive immunity to Candida albicans infections. PMID:25607781

  17. Effect of quinoline based 1,2,3-triazole and its structural analogues on growth and virulence attributes of Candida albicans

    PubMed Central

    Irfan, Mohammad; Alam, Shadab; Manzoor, Nikhat

    2017-01-01

    Candida albicans, along with some other non-albicans Candida species, is a group of yeast, which causes serious infections in humans that can be both systemic and superficial. Despite the fact that extensive efforts have been put into the discovery of novel antifungal agents, the frequency of these fungal infections has increased drastically worldwide. In our quest for the discovery of novel antifungal compounds, we had previously synthesized and screened quinoline containing 1,2,3-triazole (3a) as a potent Candida spp inhibitor. In the present study, two structural analogues of 3a (3b and 3c) have been synthesized to determine the role of quinoline and their anti-Candida activities have been evaluated. Preliminary results helped us to determine 3a and 3b as lead inhibitors. The IC50 values of compound 3a for C. albicans ATCC 90028 (standard) and C. albicans (fluconazole resistant) strains were 0.044 and 2.3 μg/ml, respectively while compound 3b gave 25.4 and 32.8 μg/ml values for the same strains. Disk diffusion, growth and time kill curve assays showed significant inhibition of C. albicans in the presence of compounds 3a and 3b. Moreover, 3a showed fungicidal nature while 3b was fungistatic. Both the test compounds significantly lower the secretion of proteinases and phospholipases. While, 3a inhibited proteinase secretion in C. albicans (resistant strain) by 45%, 3b reduced phospholipase secretion by 68% in C. albicans ATCC90028 at their respective MIC values. Proton extrusion and intracellular pH measurement studies suggested that both compounds potentially inhibit the activity of H+ ATPase, a membrane protein that is crucial for various cell functions. Similarly, 95–97% reduction in ergosterol content was measured in the presence of the test compounds at MIC and MIC/2. The study led to identification of two quinoline based potent inhibitors of C. albicans for further structural optimization and pharmacological investigation. PMID:28430797

  18. Effect of quinoline based 1,2,3-triazole and its structural analogues on growth and virulence attributes of Candida albicans.

    PubMed

    Irfan, Mohammad; Alam, Shadab; Manzoor, Nikhat; Abid, Mohammad

    2017-01-01

    Candida albicans, along with some other non-albicans Candida species, is a group of yeast, which causes serious infections in humans that can be both systemic and superficial. Despite the fact that extensive efforts have been put into the discovery of novel antifungal agents, the frequency of these fungal infections has increased drastically worldwide. In our quest for the discovery of novel antifungal compounds, we had previously synthesized and screened quinoline containing 1,2,3-triazole (3a) as a potent Candida spp inhibitor. In the present study, two structural analogues of 3a (3b and 3c) have been synthesized to determine the role of quinoline and their anti-Candida activities have been evaluated. Preliminary results helped us to determine 3a and 3b as lead inhibitors. The IC50 values of compound 3a for C. albicans ATCC 90028 (standard) and C. albicans (fluconazole resistant) strains were 0.044 and 2.3 μg/ml, respectively while compound 3b gave 25.4 and 32.8 μg/ml values for the same strains. Disk diffusion, growth and time kill curve assays showed significant inhibition of C. albicans in the presence of compounds 3a and 3b. Moreover, 3a showed fungicidal nature while 3b was fungistatic. Both the test compounds significantly lower the secretion of proteinases and phospholipases. While, 3a inhibited proteinase secretion in C. albicans (resistant strain) by 45%, 3b reduced phospholipase secretion by 68% in C. albicans ATCC90028 at their respective MIC values. Proton extrusion and intracellular pH measurement studies suggested that both compounds potentially inhibit the activity of H+ ATPase, a membrane protein that is crucial for various cell functions. Similarly, 95-97% reduction in ergosterol content was measured in the presence of the test compounds at MIC and MIC/2. The study led to identification of two quinoline based potent inhibitors of C. albicans for further structural optimization and pharmacological investigation.

  19. Pseudomonas phage inhibition of Candida albicans.

    PubMed

    Nazik, Hasan; Joubert, Lydia-Marie; Secor, Patrick R; Sweere, Johanna M; Bollyky, Paul L; Sass, Gabriele; Cegelski, Lynette; Stevens, David A

    2017-10-06

    Pseudomonas aeruginosa (Pa) and Candida albicans (Ca) are major bacterial and fungal pathogens in immunocompromised hosts, and notably in the airways of cystic fibrosis patients. The bacteriophages of Pa physically alter biofilms, and were recently shown to inhibit the biofilms of Aspergillus fumigatus. To understand the range of this viral-fungal interaction, we studied Pa phages Pf4 and Pf1, and their interactions with Ca biofilm formation and preformed Ca biofilm. Both forms of Ca biofilm development, as well as planktonic Ca growth, were inhibited by either phage. The inhibition of biofilm was reversed by the addition of iron, suggesting that the mechanism of phage action on Ca involves denial of iron. Birefringence studies on added phage showed an ordered structure of binding to Ca. Electron microscopic observations indicated phage aggregation in the biofilm extracellular matrix. Bacteriophage-fungal interactions may be a general feature with several pathogens in the fungal kingdom.

  20. Miltefosine inhibits Candida albicans and non-albicans Candida spp. biofilms and impairs the dispersion of infectious cells.

    PubMed

    Vila, Taissa; Ishida, Kelly; Seabra, Sergio Henrique; Rozental, Sonia

    2016-11-01

    Candida spp. can adhere to and form biofilms over different surfaces, becoming less susceptible to antifungal treatment. Resistance of biofilms to antifungal agents is multifactorial and the extracellular matrix (ECM) appears to play an important role. Among the few available antifungals for treatment of candidaemia, only the lipid formulations of amphotericin B (AmB) and the echinocandins are effective against biofilms. Our group has previously demonstrated that miltefosine has an important effect against Candida albicans biofilms. Thus, the aim of this work was to expand the analyses of the in vitro antibiofilm activity of miltefosine to non-albicans Candida spp. Miltefosine had significant antifungal activity against planktonic cells and the development of biofilms of C. albicans, Candida parapsilosis, Candida tropicalis and Candida glabrata. The activity profile in biofilms was superior to fluconazole and was similar to that of AmB and caspofungin. Biofilm-derived cells with their ECM extracted became as susceptible to miltefosine as planktonic cells, confirming the importance of the ECM in the biofilm resistant behaviour. Miltefosine also inhibited biofilm dispersion of cells at the same concentration needed to inhibit planktonic cell growth. The data obtained in this work reinforce the potent inhibitory activity of miltefosine on biofilms of the four most pathogenic Candida spp. and encourage further studies for the utilisation of this drug and/or structural analogues on biofilm-related infections.

  1. [Prevalence of Candida albicans and Candida non-albicans in clinical samples during 1999-2001].

    PubMed

    Mujica, M T; Finquelievich, J L; Jewtuchowicz, V; Iovannitti, C A

    2004-01-01

    The importance of epidemiological monitoring of yeasts involved in pathologic processes is unquestionable due to the increase of these infections over the last decade, the changes observed in species causing candidiasis, and empirical antifungal treatment. At the Mycology Center, 1006 isolates from a wide range of clinical samples were studied during 1999-2001. Candida albicans (40.3%) was the most isolated species, although, the Candida no albicans species with 54.9% showed the major prevalence. In blood cultures Candida parapsilosis (34.9%), C. albicans (30.2%) and C. tropicalis (25.6%) were recovered most frequently while C. glabrata represented only 2.3%. C. albicans with 60%-80% was the predominant specie in mucosal surface. We also detected Candida mediastinistis, which alert us over the importance at this location. Urinary tract infections caused by yeasts were more frequent in hospitalized patients, being C. albicans (47.7%), the most commonly isolated, followed by C. glabrata (24.8%) and C. tropicalis (20.0%). In the candidal onychomycoses, C. parapsilosis (37.7%) outplaced C. albicans (22.0%). Fluconazole susceptibility studies of Candida species allowed us to conclude that the majority of C. albicans islolates are susceptible, and that the highest resistance averages were observed in C. glabrata (21.41%) and C. krusei (69.23%).

  2. Ribosomal RNA processing in Candida albicans

    PubMed Central

    Pendrak, Michael L.; Roberts, David D.

    2011-01-01

    Ribosome assembly begins with conversion of a polycistronic precursor into 18S, 5.8S, and 25S rRNAs. In the ascomycete fungus Candida albicans, rRNA transcription starts 604 nt upstream of the 18S rRNA junction (site A1). One major internal processing site in the 5′ external transcribed spacer (A0) occurs 108 nt from site A1. The A0–A1 fragment persists as a stable species during log phase growth and can be used to assess proliferation rates. Separation of the small and large subunit pre-rRNAs occurs at sites A2 and A3 in internal transcribed spacer-1 Saccharomyces cerevisiae pre-rRNA. However, the 5′ end of the 5.8S rRNA is represented by only a 5.8S (S) form, and a 7S rRNA precursor of the 5.8S rRNA extends into internal transcribed spacer 1 to site A2, which differs from S. cerevisiae. External transcribed spacer 1 and internal transcribed spacers 1 and 2 show remarkable structural similarity with S. cerevisiae despite low sequence identity. Maturation of C. albicans rRNA resembles other eukaryotes in that processing can occur cotranscriptionally or post-transcriptionally. During rapid proliferation, U3 snoRNA-dependent processing occurs before large and small subunit rRNA separation, consistent with cotranscriptional processing. As cells pass the diauxic transition, the 18S pre-rRNA accumulates into stationary phase as a 23S species, possessing an intact 5′ external transcribed spacer extending to site A3. Nutrient addition to starved cells results in the disappearance of the 23S rRNA, indicating a potential role in normal physiology. Therefore, C. albicans reveals new mechanisms that regulate post- versus cotranscriptional rRNA processing. PMID:22028364

  3. The pathogen Candida albicans hijacks pyroptosis for escape from macrophages.

    PubMed

    Uwamahoro, Nathalie; Verma-Gaur, Jiyoti; Shen, Hsin-Hui; Qu, Yue; Lewis, Rowena; Lu, Jingxiong; Bambery, Keith; Masters, Seth L; Vince, James E; Naderer, Thomas; Traven, Ana

    2014-03-25

    The fungal pathogen Candida albicans causes macrophage death and escapes, but the molecular mechanisms remained unknown. Here we used live-cell imaging to monitor the interaction of C. albicans with macrophages and show that C. albicans kills macrophages in two temporally and mechanistically distinct phases. Early upon phagocytosis, C. albicans triggers pyroptosis, a proinflammatory macrophage death. Pyroptosis is controlled by the developmental yeast-to-hypha transition of Candida. When pyroptosis is inactivated, wild-type C. albicans hyphae cause significantly less macrophage killing for up to 8 h postphagocytosis. After the first 8 h, a second macrophage-killing phase is initiated. This second phase depends on robust hyphal formation but is mechanistically distinct from pyroptosis. The transcriptional regulator Mediator is necessary for morphogenesis of C. albicans in macrophages and the establishment of the wild-type surface architecture of hyphae that together mediate activation of macrophage cell death. Our data suggest that the defects of the Mediator mutants in causing macrophage death are caused, at least in part, by reduced activation of pyroptosis. A Mediator mutant that forms hyphae of apparently wild-type morphology but is defective in triggering early macrophage death shows a breakdown of cell surface architecture and reduced exposed 1,3 β-glucan in hyphae. Our report shows how Candida uses host and pathogen pathways for macrophage killing. The current model of mechanical piercing of macrophages by C. albicans hyphae should be revised to include activation of pyroptosis by hyphae as an important mechanism mediating macrophage cell death upon C. albicans infection. IMPORTANCE Upon phagocytosis by macrophages, Candida albicans can transition to the hyphal form, which causes macrophage death and enables fungal escape. The current model is that the highly polarized growth of hyphae results in macrophage piercing. This model is challenged by recent

  4. Mucosal biofilms of Candida albicans.

    PubMed

    Ganguly, Shantanu; Mitchell, Aaron P

    2011-08-01

    Biofilms are microbial communities that form on surfaces and are embedded in an extracellular matrix. C. albicans forms pathogenic mucosal biofilms that are evoked by changes in host immunity or mucosal ecology. Mucosal surfaces are inhabited by many microbial species; hence these biofilms are polymicrobial. Several recent studies have applied paradigms of biofilm analysis to study mucosal C. albicans infections. These studies reveal that the Bcr1 transcription factor is a master regulator of C. albicans biofilm formation under diverse conditions, though the most relevant Bcr1 target genes can vary with the biofilm niche. An important determinant of mucosal biofilm formation is the interaction with host defenses. Finally, studies of interactions between bacterial species and C. albicans provide insight into the communication mechanisms that endow polymicrobial biofilms with unique properties.

  5. E1210, a new broad-spectrum antifungal, suppresses Candida albicans hyphal growth through inhibition of glycosylphosphatidylinositol biosynthesis.

    PubMed

    Watanabe, Nao-Aki; Miyazaki, Mamiko; Horii, Takaaki; Sagane, Koji; Tsukahara, Kappei; Hata, Katsura

    2012-02-01

    Continued research toward the development of new antifungals that act via inhibition of glycosylphosphatidylinositol (GPI) biosynthesis led to the design of E1210. In this study, we assessed the selectivity of the inhibitory activity of E1210 against Candida albicans GWT1 (Orf19.6884) protein, Aspergillus fumigatus GWT1 (AFUA_1G14870) protein, and human PIG-W protein, which can catalyze the inositol acylation of GPI early in the GPI biosynthesis pathway, and then we assessed the effects of E1210 on key C. albicans virulence factors. E1210 inhibited the inositol acylation activity of C. albicans Gwt1p and A. fumigatus Gwt1p with 50% inhibitory concentrations (IC(50)s) of 0.3 to 0.6 μM but had no inhibitory activity against human Pig-Wp even at concentrations as high as 100 μM. To confirm the inhibition of fungal GPI biosynthesis, expression of ALS1 protein, a GPI-anchored protein, on the surfaces of C. albicans cells treated with E1210 was studied and shown to be significantly lower than that on untreated cells. However, the ALS1 protein levels in the crude extract and the RHO1 protein levels on the cell surface were found to be almost the same. Furthermore, E1210 inhibited germ tube formation, adherence to polystyrene surfaces, and biofilm formation of C. albicans at concentrations above its MIC. These results suggested that E1210 selectively inhibited inositol acylation of fungus-specific GPI which would be catalyzed by Gwt1p, leading to the inhibition of GPI-anchored protein maturation, and also that E1210 suppressed the expression of some important virulence factors of C. albicans, through its GPI biosynthesis inhibition.

  6. The effect of parenteral alimentation fluid, undiluted with saline or fresh sera, on the growth of Candida albicans in vitro at 37 degrees C.

    PubMed

    Lederer, T; Rippon, J; Baldwin, S; Pachman, L M

    1975-02-28

    Parenteral alimentation is often complicated by Candida albicans infection which may be fatal. This study investigated the effect of alimentation fluid (Aminosol) on C. albicans' growth in vitro. It was found that concentrated Aminosol (1400 millisomoles) maintained C. albicans in a viable state but inhibited replication. Dilution of alimentation fluid to physiological concentrations (300 milliosmoles) with either saline or aged pooled normal sera promoted in vitro growth of C. albicans which was equivalent to that obtained in BHI broth and was slightly less than that obtained in Sabouraud's broth. The effects of fresh sera with full complement activity were also investigated. In fresh sera appropriately diluted with physiological saline, some clumping of the yeasts was observed and all formed germ tubes. Growth as defined by budding or the formation of hyphae was inhibited. When Aminosol was diluted to 300 milliosomoles with fresh sera, all yeasts were noted to be in clumps with germ tubes as well as continually growing hyphae. Growth was approximately equal to that seen in Aminosol similarly diluted with saline.

  7. Candida albicans isolates from a Malaysian hospital exhibit more potent phospholipase and haemolysin activities than non-albicans Candida isolates.

    PubMed

    Chin, V K; Foong, K J; Maha, A; Rusliza, B; Norhafizah, M; Ng, K P; Chong, P P

    2013-12-01

    This study was aimed at determining the phospholipase and haemolysin activity of Candida isolates in Malaysia. A total of 37 Candida clinical isolates representing seven species, Candida albicans (12), Candida tropicalis (8), Candida glabrata (4), Candida parapsilosis (1), Candida krusei (4), Candida orthopsilosis (1) and Candida rugosa (7) were tested. In vitro phospholipase activity was determined by using egg yolk plate assay whereas in vitro haemolysin activity was tested by using blood plate assay on sheep blood Sabouraud's dextrose agar (SDA) enriched with glucose. Phospholipase activity was detected in 75% (9 out of 12) of the C. albicans isolates. Among the 25 non- C. albicans Candida isolates, phospholipase activity was detected in only 24% of these isolates. The phospholipase activity of C. albicans was significantly higher than that of the non- C. albicans Candida isolates (P=0.002). Haemolysin activity was detected in 100% of the C. albicans, C. tropicalis, C. glabrata, C. krusei, C. parapsilosis, and C. orthopsilosis isolates while 75% of the C. krusei isolates and 12.3% of the C. rugosa isolates showed haemolysin activity. The haemolytic activity of C. albicans was significantly higher than that of the non- C. albicans Candida isolates (P=0.0001).The findings in this study indicate that C. albicans isolates in Malaysia may possess greater virulence potential than the non-albicans species.

  8. Azole Antifungal Resistance in Candida albicans and Emerging Non-albicans Candida Species

    PubMed Central

    Whaley, Sarah G.; Berkow, Elizabeth L.; Rybak, Jeffrey M.; Nishimoto, Andrew T.; Barker, Katherine S.; Rogers, P. David

    2017-01-01

    Within the limited antifungal armamentarium, the azole antifungals are the most frequent class used to treat Candida infections. Azole antifungals such as fluconazole are often preferred treatment for many Candida infections as they are inexpensive, exhibit limited toxicity, and are available for oral administration. There is, however, extensive documentation of intrinsic and developed resistance to azole antifungals among several Candida species. As the frequency of azole resistant Candida isolates in the clinical setting increases, it is essential to elucidate the mechanisms of such resistance in order to both preserve and improve upon the azole class of antifungals for the treatment of Candida infections. This review examines azole resistance in infections caused by C. albicans as well as the emerging non-albicans Candida species C. parapsilosis, C. tropicalis, C. krusei, and C. glabrata and in particular, describes the current understanding of molecular basis of azole resistance in these fungal species. PMID:28127295

  9. Non-albicans Candida Infection: An Emerging Threat

    PubMed Central

    Deorukhkar, Sachin C.; Saini, Santosh

    2014-01-01

    The very nature of infectious diseases has undergone profound changes in the past few decades. Fungi once considered as nonpathogenic or less virulent are now recognized as a primary cause of morbidity and mortality in immunocompromised and severely ill patients. Candida spp. are among the most common fungal pathogens. Candida albicans was the predominant cause of candidiasis. However, a shift toward non-albicans Candida species has been recently observed. These non-albicans Candida species demonstrate reduced susceptibility to commonly used antifungal drugs. In the present study, we investigated the prevalence of non-albicans Candida spp. among Candida isolates from various clinical specimens and analysed their virulence factors and antifungal susceptibility profile. A total of 523 Candida spp. were isolated from various clinical specimens. Non-albicans Candida species were the predominant pathogens isolated. Non-albicans Candida species also demonstrated the production of virulence factors once attributed to Candida albicans. Non-albicans Candida demonstrated high resistance to azole group of antifungal agents. Therefore, it can be concluded that non-albicans Candida species have emerged as an important cause of infections. Their isolation from clinical specimen can no longer be ignored as a nonpathogenic isolate nor can it be dismissed as a contaminant. PMID:25404942

  10. Interspecies Interactions between Clostridium difficile and Candida albicans

    PubMed Central

    van Leeuwen, Pim T.; van der Peet, Jasper M.; Bikker, Floris J.; Hoogenkamp, Michel A.; Oliveira Paiva, Ana M.; Kostidis, Sarantos; Mayboroda, Oleg A.

    2016-01-01

    ABSTRACT The facultative anaerobic polymorphic fungus Candida albicans and the strictly anaerobic Gram-positive bacterium Clostridium difficile are two opportunistic pathogens residing in the human gut. While a few studies have focused on the prevalence of C. albicans in C. difficile-infected patients, the nature of the interactions between these two microbes has not been studied thus far. In the current study, both chemical and physical interactions between C. albicans and C. difficile were investigated. In the presence of C. albicans, C. difficile was able to grow under aerobic, normally toxic, conditions. This phenomenon was neither linked to adherence of bacteria to hyphae nor to biofilm formation by C. albicans. Conditioned medium of C. difficile inhibited hyphal growth of C. albicans, which is an important virulence factor of the fungus. In addition, it induced hypha-to-yeast conversion. p-Cresol, a fermentation product of tyrosine produced by C. difficile, also induced morphological effects and was identified as an active component of the conditioned medium. This study shows that in the presence of C. albicans, C. difficile can persist and grow under aerobic conditions. Furthermore, p-cresol, produced by C. difficile, is involved in inhibiting hypha formation of C. albicans, directly affecting the biofilm formation and virulence of C. albicans. This study is the first detailed characterization of the interactions between these two gut pathogens. IMPORTANCE Candida albicans and Clostridium difficile are two opportunistic pathogens that reside in the human gut. A few studies have focused on the prevalence of C. albicans in C. difficile-infected patients, but none have shown the interaction(s) that these two organisms may or may not have with each other. In this study, we used a wide range of different techniques to better understand this interaction at a macroscopic and microscopic level. We found that in the presence of C. albicans, C

  11. Stenotrophomonas maltophilia interferes via the DSF-mediated quorum sensing system with Candida albicans filamentation and its planktonic and biofilm modes of growth.

    PubMed

    de Rossi, Beatriz Passerini; García, Carlos; Alcaraz, Eliana; Franco, Mirta

    2014-01-01

    Stenotrophomonas maltophilia is a nosocomial pathogen of increasing importance. S. maltophilia K279a genome encodes a diffusible signal factor (DSF) dependent quorum sensing (QS) system that was first identified in Xanthomonas campestris pv. campestris. DSF from X. campestris is a homologue of farnesoic acid, a Candida albicans QS signal which inhibits the yeast-to-hyphal shift. Here we describe the antagonistic effects of S. maltophilia on C. albicans on filamentation as well as on its planktonic and biofilm modes of growth. To determine the role of the DSF-mediated quorum sensing system in these effects, C. albicans ATCC 10231 and C. albicans tup1 mutant, locked in the filamentous form, were grown with K279a or with its rpfF deletion mutant (DSF-). A significant reduction in viable counts of C. albicans was observed in planktonic cocultures with K279a as well as in mixed biofilms. Furthermore, no viable cells of C. albicans tup1 were recovered from K279a mixed biofilms. Fungal viability was also assessed by labeling biofilms with SYTO 9 and propidium iodide. Confocal images showed that K279a can kill hyphae and also yeast cells. Light microscopic analysis showed that K279a severely affects hyphae integrity. On the other hand, the presence of K279a rpfF did not affect fungal morphology or viability. In conclusion, we report for the first time that S. maltophilia interferes with two key virulence factors of C. albicans, the yeast-to-hyphal transition and biofilm formation. DSF could be directly responsible for these effects or may induce the gene expression involved in antifungal activity. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España. All rights reserved.

  12. Pathogenicity and virulence of Candida dubliniensis: comparison with C. albicans.

    PubMed

    Vilela, M M S; Kamei, K; Sano, A; Tanaka, R; Uno, J; Takahashi, I; Ito, J; Yarita, K; Miyaji, M

    2002-06-01

    Candida dubliniensis is a newly described fungus that is frequently isolated from the oral cavities of HIV-positive patients. Although extensive studies have been performed on the phylogeny of C. dubliniensis, little is known about the pathogenic ecology of this yeast. Here we examined aspects related to C. dubliniensis in comparison with those of C. albicans. When injected intravenously into mice, C. dubliniensis had a higher survival rate than C. albicans. Histopathological analysis disclosed that C. dubliniensis remained mostly in the yeast form in the infected organs, whereas C. albicans changed into the mycelial form. The host inflammatory reaction was aggressive with C. dubliniensis infection and mild with C. albicans infection. Co-culture of the yeasts with human polymorphonuclear leukocytes disclosed that C. dubliniensis is more vulnerable to the fungicidal activity of leukocytes than C. albicans. C. dubliniensis was also more susceptible to the toxic effect of hydrogen peroxide. When cultured in vitro, C. dubliniensis grew more slowly than C. albicans, but the formation of germ tubes was faster. When the fungi were cultured in RPMI 1640, a fetal bovine serum supplement suppressed the growth of C. dubliniensis but enhanced that of C. albicans. These results clearly indicated that C. dubliniensis is less virulence than C. albicans.

  13. Molecular Epidemiology of Candida albicans and Its Closely Related Yeasts Candida dubliniensis and Candida africana▿

    PubMed Central

    Romeo, Orazio; Criseo, Giuseppe

    2009-01-01

    We performed a molecular study to determine the occurrence of Candida albicans, Candida africana, and Candida dubliniensis in different clinical samples. The study provides new insights into the epidemiology of candidiasis in hospitalized patients in three hospitals in southern Italy. It also reports the first detailed epidemiological data concerning the occurrence of C. africana in clinical samples. PMID:18987171

  14. CAP1, an adenylate cyclase-associated protein gene, regulates bud-hypha transitions, filamentous growth, and cyclic AMP levels and is required for virulence of Candida albicans.

    PubMed

    Bahn, Y S; Sundstrom, P

    2001-05-01

    In response to a wide variety of environmental stimuli, the opportunistic fungal pathogen Candida albicans exits the budding cycle, producing germ tubes and hyphae concomitant with expression of virulence genes, such as that encoding hyphal wall protein 1 (HWP1). Biochemical studies implicate cyclic AMP (cAMP) increases in promoting bud-hypha transitions, but genetic evidence relating genes that control cAMP levels to bud-hypha transitions has not been reported. Adenylate cyclase-associated proteins (CAPs) of nonpathogenic fungi interact with Ras and adenylate cyclase to increase cAMP levels under specific environmental conditions. To initiate studies on the relationship between cAMP signaling and bud-hypha transitions in C. albicans, we identified, cloned, characterized, and disrupted the C. albicans CAP1 gene. C. albicans strains with inactivated CAP1 budded in conditions that led to germ tube formation in isogenic strains with CAP1. The addition of 10 mM cAMP and dibutyryl cAMP promoted bud-hypha transitions and filamentous growth in the cap1/cap1 mutant in liquid and solid media, respectively, showing clearly that cAMP promotes hypha formation in C. albicans. Increases in cytoplasmic cAMP preceding germ tube emergence in strains having CAP1 were markedly diminished in the budding cap1/cap1 mutant. C. albicans strains with deletions of both alleles of CAP1 were avirulent in a mouse model of systemic candidiasis. The avirulence of a germ tube-deficient cap1/cap1 mutant coupled with the role of Cap1 in regulating cAMP levels shows that the Cap1-mediated cAMP signaling pathway is required for bud-hypha transitions, filamentous growth, and the pathogenesis of candidiasis.

  15. CAP1, an Adenylate Cyclase-Associated Protein Gene, Regulates Bud-Hypha Transitions, Filamentous Growth, and Cyclic AMP Levels and Is Required for Virulence of Candida albicans

    PubMed Central

    Bahn, Yong-Sun; Sundstrom, Paula

    2001-01-01

    In response to a wide variety of environmental stimuli, the opportunistic fungal pathogen Candida albicans exits the budding cycle, producing germ tubes and hyphae concomitant with expression of virulence genes, such as that encoding hyphal wall protein 1 (HWP1). Biochemical studies implicate cyclic AMP (cAMP) increases in promoting bud-hypha transitions, but genetic evidence relating genes that control cAMP levels to bud-hypha transitions has not been reported. Adenylate cyclase-associated proteins (CAPs) of nonpathogenic fungi interact with Ras and adenylate cyclase to increase cAMP levels under specific environmental conditions. To initiate studies on the relationship between cAMP signaling and bud-hypha transitions in C. albicans, we identified, cloned, characterized, and disrupted the C. albicans CAP1 gene. C. albicans strains with inactivated CAP1 budded in conditions that led to germ tube formation in isogenic strains with CAP1. The addition of 10 mM cAMP and dibutyryl cAMP promoted bud-hypha transitions and filamentous growth in the cap1/cap1 mutant in liquid and solid media, respectively, showing clearly that cAMP promotes hypha formation in C. albicans. Increases in cytoplasmic cAMP preceding germ tube emergence in strains having CAP1 were markedly diminished in the budding cap1/cap1 mutant. C. albicans strains with deletions of both alleles of CAP1 were avirulent in a mouse model of systemic candidiasis. The avirulence of a germ tube-deficient cap1/cap1 mutant coupled with the role of Cap1 in regulating cAMP levels shows that the Cap1-mediated cAMP signaling pathway is required for bud-hypha transitions, filamentous growth, and the pathogenesis of candidiasis. PMID:11325951

  16. Isolation and partial characterisation of a new antiproliferative substance from human leucocytes inhibiting growth of Candida albicans

    PubMed Central

    Naess-Andresen, C F; Ekeberg, D; Fagerhol, M K; Sandvik, K; Staahl, L

    2003-01-01

    Aim: To purify and partially characterise a fraction from human leucocytes containing a substance cytotoxic to Candida albicans. Methods: Leucocytes were isolated from the buffy coats of healthy blood donors. The cytotoxic factor (CF) was isolated from the soluble fraction of the cells. A cell lysate was passed through a filter with a cut off value of 3 kDa, and the filtrate was processed by anionic exchange chromatography and gel filtration. The purified CF was analysed for its chemical and biological properties. The cytotoxicity of CF was tested on C albicans grown on agar plates. Results: Mass spectrometry showed a molecular mass of 2.148 kDa. CF was found in polymorphonuclear neutrophilic cells only. No amino acids were detected, and a low ultraviolet absorbance at 260 nm and resistance to nuclease indicate the absence of nucleic acids. An anthrone test was positive for carbohydrate. The substance was soluble in water. CF showed a dose related cytotoxicity in the range of 0.1–1 mg/ml. The cytotoxic effect was abrogated by zinc ions. Preliminary testing indicated that CF also had cytotoxic effects against some bacteria. Conclusions: This report describes a factor from isolated human leucocytes that is cytotoxic to C albicans. The substance contains a carbohydrate moiety, whereas no amino acids were detected. The cytotoxicity can be abrogated by zinc ions in vitro. This substance is probably part of the repertoire by which leucocytes prevent infections. PMID:12890745

  17. AI-2 of Aggregatibacter actinomycetemcomitans inhibits Candida albicans biofilm formation.

    PubMed

    Bachtiar, Endang W; Bachtiar, Boy M; Jarosz, Lucja M; Amir, Lisa R; Sunarto, Hari; Ganin, Hadas; Meijler, Michael M; Krom, Bastiaan P

    2014-01-01

    Aggregatibacter actinomycetemcomitans, a Gram-negative bacterium, and Candida albicans, a polymorphic fungus, are both commensals of the oral cavity but both are opportunistic pathogens that can cause oral diseases. A. actinomycetemcomitans produces a quorum-sensing molecule called autoinducer-2 (AI-2), synthesized by LuxS, that plays an important role in expression of virulence factors, in intra- but also in interspecies communication. The aim of this study was to investigate the role of AI-2 based signaling in the interactions between C. albicans and A. actinomycetemcomitans. A. actinomycetemcomitans adhered to C. albicans and inhibited biofilm formation by means of a molecule that was secreted during growth. C. albicans biofilm formation increased significantly when co-cultured with A. actinomycetemcomitans luxS, lacking AI-2 production. Addition of wild-type-derived spent medium or synthetic AI-2 to spent medium of the luxS strain, restored inhibition of C. albicans biofilm formation to wild-type levels. Addition of synthetic AI-2 significantly inhibited hypha formation of C. albicans possibly explaining the inhibition of biofilm formation. AI-2 of A. actinomycetemcomitans is synthesized by LuxS, accumulates during growth and inhibits C. albicans hypha- and biofilm formation. Identifying the molecular mechanisms underlying the interaction between bacteria and fungi may provide important insight into the balance within complex oral microbial communities.

  18. Multi-species biofilm of Candida albicans and non-Candida albicans Candida species on acrylic substrate

    PubMed Central

    K PATHAK, Apurva; SHARMA, Sanjay; SHRIVASTVA, Pallavi

    2012-01-01

    Objective In polymicrobial biofilms bacteria extensively interact with Candida species, but the interaction among the different species of the Candida is yet to be completely evaluated. In the present study, the difference in biofilm formation ability of clinical isolates of four species of Candida in both single-species and multi-species combinations on the surface of dental acrylic resin strips was evaluated. Material and Methods The species of Candida, isolated from multiple species oral candidiasis of the neutropenic patients, were used for the experiment. Organisms were cultured on Sabouraud dextrose broth with 8% glucose (SDB). Biofilm production on the acrylic resins strips was determined by crystal violet assay. Student's t-test and ANOVA were used to compare in vitro biofilm formation for the individual species of Candida and its different multi-species combinations. Results In the present study, differences between the mean values of the biofilm-forming ability of individual species (C. glabrata>C. krusei>C. tropicalis>C. albicans) and in its multi-species' combinations (the highest for C. albicans with C. glabrata and the lowest for all the four species combination) were reported. Conclusions The findings of this study showed that biofilm-forming ability was found greater for non-Candida albicans Candida species (NCAC) than for C. albicans species with intra-species variation. Presence of C. albicans in multi-species biofilms increased, whereas; C. tropicalis decreased the biofilm production with all other NCAC species. PMID:22437681

  19. Growing Candida albicans Biofilms on Paper Support and Dynamic Conditions.

    PubMed

    Selow, Marcela Lima Cardoso; Rymovicz, Alinne Ulbrich Mores; Ribas, Cristina Rauen; Saad, Renata Simão; Rosa, Rosimeire Takaki; Rosa, Edvaldo Antonio Ribeiro

    2015-08-01

    A stainless steel paper-embedded biofilm reactor (PEBR) was developed for Candida spp. growth, permitting confluent distribution of nutrients by capillary diffusion through ordinary laboratory filter paper. Antibiogram disks were distributed along the filter paper rim, and the PEBR received 0.1 or 0.01 % crystal violet (CV) at 200 μL min(-1) and at 37 °C, for 48 h. CV was recovered from the disks and measured at 540 nm. Candida albicans SC5314 cells were applied onto antibiogram disks. The bioreactor was assembled, and YEPD broth was admitted (200 μL min(-1)) at 37 °C, for 72 h. Biofilm growth was estimated via the MTT reduction test. Controls were disks that received the same treatments, except for the fungus. The PEBR was considered high-throughput table, low-cost, and feasible to grow C. albicans biofilms.

  20. Effect of plant oils on Candida albicans.

    PubMed

    Agarwal, Vishnu; Lal, Priyanka; Pruthi, Vikas

    2010-10-01

    Candida species, notably Candida albicans, is the major fungal pathogen in humans. It is a dimorphic fungus capable of causing superficial mucosal infections, as well as systemic infections, in immunocompromised individuals. The factors responsible for its pathogenesis are still not fully understood and increasing resistance to commonly used antifungal agents necessitates the search for new formulations. The inhibitory effect of 30 different plant oils on Candida albicans isolated from clinical samples was evaluated. The antifungal agent fluconazole was used as a positive control. Plant oils were tested at concentrations from 0.03% to 3% (v/v) to determine the minimum inhibitory concentration and minimum fungicidal concentration (MFC) using agar dilution and macro broth dilution assays. Of the 30 plant oils tested, 18 were found to be effective and 12 were ineffective. Based on their MFCs, effective oils were placed into three categories: most effective, moderately effective and least effective. Eucalyptus and peppermint oils were most effective, with MFC values of 0.12% and 0.15% (v/v), respectively. The significant antifungal activity of these oils suggests that they could serve as a source of compounds with therapeutic potential against Candida-related infections. Copyright © 2010 Taiwan Society of Microbiology. Published by Elsevier B.V. All rights reserved.

  1. Proteolytic activity and cytokine up-regulation by non-albicans Candida albicans.

    PubMed

    Nawaz, Ali; Pärnänen, Pirjo; Kari, Kirsti; Meurman, Jukka H

    2015-05-01

    Mouth is an important source of infections and oral infections such as Candida infections increase the risk of mortality. Our purpose was to investigate differences in proteolytic activity of non-albicans Candida albicans (non-albicans Candida) between clinical isolates and laboratory samples. The second aim was to assess the concentration of pro- and anti-inflammatory cytokine levels IL-1β, IL-10, and TNF-α in saliva of patients with the non-albicans Candida and Candida-negative saliva samples. Clinical yeast samples from our laboratory were used for analyses. Candida strains were grown in YPG at 37 °C for 24 h in water bath with shaking. The activity of Candida proteinases of cell and cell-free fractions were analyzed by MDPF-gelatin zymography. The levels of IL-1β, IL-10, and TNF-α were measured from saliva with ELISA. The study showed differences in the proteolytic activity among the non-albicans Candida strains. C. tropicalis had higher proteolytic activity when compared to the other strains. Significant difference was found in salivary IL-1β levels between the non-albicans Candida and control strains (P < 0.002). The present findings showed differences in proteolytic activity among the non-albicans Candida strains. The increased IL-1β concentration may be one of the host response components associated with non-albicans Candida infection.

  2. Early Adhesion of Candida albicans onto Dental Acrylic Surfaces.

    PubMed

    Aguayo, S; Marshall, H; Pratten, J; Bradshaw, D; Brown, J S; Porter, S R; Spratt, D; Bozec, L

    2017-07-01

    Denture-associated stomatitis is a common candidal infection that may give rise to painful oral symptoms, as well as be a reservoir for infection at other sites of the body. As poly (methyl methacrylate) (PMMA) remains the main material employed in the fabrication of dentures, the aim of this research was to evaluate the adhesion of Candida albicans cells onto PMMA surfaces by employing an atomic force microscopy (AFM) single-cell force spectroscopy (SCFS) technique. For experiments, tipless AFM cantilevers were functionalized with PMMA microspheres and probed against C. albicans cells immobilized onto biopolymer-coated substrates. Both a laboratory strain and a clinical isolate of C. albicans were used for SCFS experiments. Scanning electron microscopy (SEM) and AFM imaging of C. albicans confirmed the polymorphic behavior of both strains, which was dependent on growth culture conditions. AFM force-spectroscopy results showed that the adhesion of C. albicans to PMMA is morphology dependent, as hyphal tubes had increased adhesion compared with yeast cells ( P < 0.05). C. albicans budding mother cells were found to be nonadherent, which contrasts with the increased adhesion observed in the tube region. Comparison between strains demonstrated increased adhesion forces for a clinical isolate compared with the lab strain. The clinical isolate also had increased survival in blood and reduced sensitivity to complement opsonization, providing additional evidence of strain-dependent differences in Candida-host interactions that may affect virulence. In conclusion, PMMA-modified AFM probes have shown to be a reliable technique to characterize the adhesion of C. albicans to acrylic surfaces.

  3. Epithelial Cell Innate Response to Candida albicans

    PubMed Central

    Naglik, J.R.; Moyes, D.

    2011-01-01

    With the advent of treatments and diseases such as AIDS resulting in increasing numbers of patients with suppressed immune systems, fungal diseases are an escalating problem. Candida albicans is the most common of these fungal pathogens, causing infections in many of these patients. It is therefore important to understand how immunity to this fungus is regulated and how it might be manipulated. Although work has been done to identify the receptors, fungal moieties, and responses involved in anti-Candida immunity, most studies have investigated interactions with myeloid or lymphoid cells. Given that the first site of contact of C. albicans with its host is the mucosal epithelial surface, recent studies have begun to focus on interactions of C. albicans with this site. The results are startling yet in retrospect obvious, indicating that epithelial cells play an important role in these interactions, initiating responses and even providing a level of protection. These findings have obvious implications, not just for fungal pathogens, but also for identifying how host organisms can distinguish between commensal and pathogenic microbes. This review highlights some of these recent findings and discusses their importance in the wider context of infection and immunity. PMID:21441481

  4. Accumulation of acyclic polyols and trehalose as related to growth form and carbohydrate source in the dimorphic fungi Mucor rouxii and Candida albicans.

    PubMed

    Pfyffer, G E; Rast, D M

    1989-01-01

    Yeast (Y) and hyphal (H) cells of Mucor rouxii and Candida albicans were cultivated in liquid media containing different carbon nutrient sources (glucose, fructose, ribose) and their free acyclic polyol and trehalose contents determined using capillary gas liquid chromatography (TMS- and OAc-derivatization). Irrespective of growth form and C-source, the fraction of the water-soluble neutral components of the cellular mass of the cultures - highly homogeneous with regard to the respective cell form produced - contained glycerol, ribitol and arabitol, in addition to trehalose. The polyols contributed 0.5-2% to the biomass of M. rouxii and 1.5-6% to that of C. albicans; the values for trehalose ranged from 0.2-11% in the former and 1-3.5% in the latter species. Mucor contained higher amounts of ribitol and arabitol in H cells and larger quantities of trehalose and glycerol in Y cells. In Candida, too, hyphae always exhibited higher ribitol contents, whereas arabitol attained higher levels in yeasts under almost any conditions - regardless of the type of medium (synthetic vs. complex), stage of culture (early vs. late log-phase) and strain used. Glycerol concentration was not correlated with the growth form; trehalose contents tended to be higher in Y cells. Taking into account the facts that C. albicans and certain Mucor species are agents of opportunistic infections and are invasive mainly in the filamentous form, and that the prospective hosts do not accumulate either of these carbohydrates, the possibility is considered of using trehalose- and polyol-metabolizing enzymes as targets for designing antifungal drugs.

  5. Candida albicans and non-Candida albicans fungemia in an institutional hospital during a decade.

    PubMed

    Parmeland, Laurence; Gazon, Mathieu; Guerin, Claude; Argaud, Laurent; Lehot, Jean-Jacques; Bastien, Olivier; Allaouchiche, Bernard; Michallet, Mauricette; Picot, Stephane; Bienvenu, Anne-Lise

    2013-01-01

    Since the outcomes of patients with candidemia is poor and Candida spp. with increased resistance to antifungal therapy may be associated with these results, the emergence of these blood infections caused by non-C. albicans Candida spp. was explored prospectively over a two-year period (2009-2010). Candidemia was defined as the recovery of Candida spp. in culture from a patient's blood sample. The in vitro susceptibility of each isolate to amphotericin B, caspofungin, fluconazole and voriconazole was determined. In addition, characteristics of patients and outcomes were investigated in real-time. The Candida distribution was compared to that observed in a similar study 10 years earlier in the same hospital. A total of 182 patients with candidemia were included in the study. While C. albicans was the most frequently isolated species (n = 102), non-C. albicans Candida spp. included; C. glabrata (n = 32), C. parapsilosis (n = 21), C. tropicalis (n = 13), C. krusei (n = 8), C. kefyr (n = 3), C. lusitaniae (n = 2), C. lipolytica (n = 2), C. famata (n = 1), C. guilliermondii (n = 1), C. inconspicua (n = 1), C. dubliniensis (n = 1), C. sake (n = 1) and C. nivariensis (n = 1). In seven patients, C. albicans was associated with another Candida spp. Surprisingly, this prospective study demonstrated that regardless of the department (intensive care unit or hematological department), Candida spp. distribution was no different from that found in the 1998-2001 survey, except for C. krusei. A reduction in the proportion of C. krusei isolates was observed from 2000-2010 (P = 0.028) as a result of its decreased recovery in the hematological department.

  6. [Candida albicans endocarditis after pulmonary artery banding].

    PubMed

    Talvard, M; Paranon, S; Dulac, Y; Mansir, T; Kreitmann, B; Acar, P

    2009-08-01

    Endocarditis is uncommon in infants and is exceptionally related to Candida albicans on pulmonary banding. We report on a case in a 7-month-old infant who had pulmonary artery banding for a ventricular septal defect and who presented with candidal endocarditis. Banding was chosen because of the patient's poor trophic and unstable status, which could be risky for surgery involving extracorporeal circulation. A few weeks after the banding, the patient developed systemic Candida infection, which was treated successfully. At 7 months, cardiac failure appeared without fever or inflammatory signs. Cardiac echography showed that the banding was not protective as well as a hyperechogenic image on the pulmonary bifurcation. The angioscan showed a hypodense thrombus. Emergency surgery was performed consisting of pulmonary artery exploration, thrombectomy, and ventricular septal defect closure. The exploration showed a pulmonary artery perforation caused by the infected pseudoaneurysm and the migration of the banding into the pulmonary artery. The anatomopathologic analysis of the vegetation identified multisensitive Candida albicans. After surgery and prolonged antifungal treatment, progression was satisfactory.

  7. A morphogenetic regulatory role for ethyl alcohol in Candida albicans.

    PubMed

    Chauhan, Nitin M; Raut, Jayant S; Karuppayil, S Mohan

    2011-11-01

    Regulation of morphogenesis through the production of chemical signalling molecules such as isoamyl alcohol, 2-phenylethyl alcohol, 1-dodecanol, E-nerolidol and farnesol is reported in Candida albicans. The present study focuses on the effect of ethyl alcohol on C. albicans dimorphism and biofilm development. Ethyl alcohol inhibited germ tube formation induced by the four standard inducers in a concentration-dependent manner. The germ tube inhibitory concentration (4%) did not have any effect on the growth and viability of C. albicans cells. Ethyl alcohol also inhibited the elongation of germ tubes. Four percentage of ethyl alcohol significantly inhibited biofilm development on polystyrene and silicone surfaces. We suggest a potential morphogenetic regulatory role for ethyl alcohol, which may influence dissemination, virulence and establishment of infection. © 2011 Blackwell Verlag GmbH.

  8. Antifungal activity of Morinda citrifolia fruit extract against Candida albicans.

    PubMed

    Jainkittivong, Aree; Butsarakamruha, Tassanee; Langlais, Robert P

    2009-09-01

    The objective of the study was to investigate the antifungal activity of Morinda citrifolia fruit extract on Candida albicans. Juice extract from M. citrifolia fruit was lyophilized and used in antifungal testing. Antifungal activity of M. citrifolia fruit extract against C. albicans was tested in vitro at various concentrations and for different contact times. The inhibitory effect of M. citrifolia extract on C. albicans was determined by cultures and an applied broth dilution test. Using cultures, growth of C. albicans was not detected with 50 mg/mL of extract at 30-minute contact time or with 60 mg/mL of extract at 15-minute contact time. By the broth dilution test, the minimum fungicidal concentration of extract against C. albicans was 40 mg/mL at 90-minute contact time or with 50 mg/mL at 15-minute contact time. M. citrifolia fruit extract had an antifungal effect on C. albicans and the inhibitory effect varied with concentration and contact time.

  9. Mechanism underlying renal failure caused by pathogenic Candida albicans infection.

    PubMed

    Jae-Chen, Shin; Young-Joo, Jeon; Seon-Min, Park; Kang Seok, Seo; Jung-Hyun, Shim; Jung-Il, Chae

    2015-03-01

    Candida albicans (C. albicans) is an opportunistic fungal pathogen that commonly causes nosocomial infections. Systemic candidiasis is encountered with increasing frequency in immunocompromised hosts, leading to renal failure that results in severe morbidity and mortality. The present study investigated the mechanisms underlying kidney susceptibility following infection with several C. albicans strains, such as B311 and SC5314. Fungal growth of the highly virulent SC5314 strain was 10(3)-fold higher compared to the nonpathogenic B311 strain in the kidneys. An intravenous challenge of SC5314 in mice, elevated blood urea nitrogen (BUN) and creatine levels, which resulted in mortality at 8 or 35 days after infection in a dose- and time-dependent manner, whereas all the B311-infected mice had BUN and creatinine levels in the normal range and survived. Whether virulent C. albicans may escape clearance by activating signaling pathways that lead to the production of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β, was investigated. B311 infections significantly elevated TNF-α and IL-1β mRNA expression in the kidneys, whereas the expression in SC5314-infected mice remained unchanged. Furthermore, B311 infection significantly elevated the plasma levels of TNF-α and IL-1β. These results indicated that the less virulent strains of C. albicans induced pro-inflammatory cytokines in mice. These results determined that an impairment of the protective mechanisms occurred in the kidneys with virulent C. albicans infection.

  10. In vitro damage of Candida albicans biofilms by chitosan

    PubMed Central

    PU, YU; LIU, AIBO; ZHENG, YUQIANG; YE, BIN

    2014-01-01

    With the increasing usage of indwelling medical devices in clinical practice, the frequency of fungal infections has increased, such as that of Candida albicans (C. albicans). Biofilms, a protected niche for microorganisms, are resistant to a range of current antifungal agents. Chitosan is a polyatomic biopolymer with advantageous biocompatibility, biodegradation, nontoxicity and antibacterial properties. To investigate the inhibitory effect of chitosan on biofilms formed by C. albicans, cell viability, 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-caboxanilide reduction, and morphological assays, including fluorescence microscopy and scanning electron microscopy (SEM), were employed. As assessed by cell viability assay, chitosan showed significant inhibitory effects on the planktonic cells and the biofilm of C. albicans in a dose-dependent manner. Fluorescence microscopy and SEM assays confirmed that the chitosan-treated group showed delayed C. albicans biofilm formation with defect morphological features, due to the inhibitory effects of the vast majority of fungal cell growth. In conclusion, C. albicans biofilms were compromised by the treatment with chitosan, providing an alternative therapeutic strategy against the fungal biofilms in the medical devices. PMID:25120626

  11. Mucosal Immunity and Candida albicans Infection

    PubMed Central

    Moyes, David L.; Naglik, Julian R.

    2011-01-01

    Interactions between mucosal surfaces and microbial microbiota are key to host defense, health, and disease. These surfaces are exposed to high numbers of microbes and must be capable of distinguishing between those that are beneficial or avirulent and those that will invade and cause disease. Our understanding of the mechanisms involved in these discriminatory processes has recently begun to expand as new studies bring to light the importance of epithelial cells and novel immune cell subsets such as Th17 T cells in these processes. Elucidating how these mechanisms function will improve our understanding of many diverse diseases and improve our ability to treat patients suffering from these conditions. In our voyage to discover these mechanisms, mucosal interactions with opportunistic commensal organisms such as the fungus Candida albicans provide insights that are invaluable. Here, we review current knowledge of the interactions between C. albicans and epithelial surfaces and how this may shape our understanding of microbial-mucosal interactions. PMID:21776285

  12. Otite externe maligne à Candida Albicans

    PubMed Central

    Elayoubi, Fahd; Lachkar, Azeddine; Aabach, Ahmed; Chouai, Mohamed; Ghailan, Mohamed Rachid

    2016-01-01

    L’otite externe maligne est une ostéomyélite de la base du crane. Le Pseudomonas aeruginosa est le germe le plus incriminé. Cependant l’origine fongique n’est pas rare. Patiente âgée de 80 ans avait présenté une otalgie gauche persistante depuis deux mois malgré un traitement bien conduit. L’examen otologique mettait en évidence des signes inflammatoires au niveau du pavillon, une sténose du conduit avec des granulomes, et otorrhée d’allure purulente. Le scanner montrait un comblement otomastoïdien, un processus inflammatoire extensif des tissus pré et rétro-auriculaire et une lyse du tympanal. Vu l’absence d’amélioration un examen mycologique a été réalisé et qui a révélé la présence de Candida Albicans. Les cas d’otite externe maligne à Candida Albicans sont rarement rapportés. L’origine fongique doit être suspecté devant la négativité des prélèvements bactériologiques et la non amélioration malgré un traitement antibiotique bien conduit, et confirmée par des prélèvements mycologiques parfois multiples. L’otite externe maligne à Candida Albicans est une infection rare potentiellement mortelle. PMID:28154677

  13. Relevant and selective activity of Pancratium illyricum L. against Candida albicans clinical isolates: a combined effect on yeast growth and virulence.

    PubMed

    Bonvicini, Francesca; Antognoni, Fabiana; Iannello, Carmelina; Maxia, Andrea; Poli, Ferruccio; Gentilomi, Giovanna Angela

    2014-10-23

    Alkaloids present in plants of the Amaryllidaceae family are secondary metabolites of high biological interest, possessing a wide range of pharmacological activities. In the search for new plant-derived compounds with antimicrobial activities, two alkaloid extracts obtained from bulbs and leaves of Pancratium illyricum L., a plant of the Amarillydaceae family, were tested for their effect on bacterial and yeast growth. The broth microdilution susceptibility test was applied to study the effect of plant extracts on the growth of reference bacterial strains and Candida albicans reference and clinical isolates strains. Extracts obtained from the different parts of the plant were tested and compared with the pure components identified in the extracts. Since matrix metalloproteinase enzymes play a role in the dissemination process of Candida albicans, the effect of the bulb extract and pure alkaloids on in vitro collagenase activity was tested. Cell viability test was carried out on human embryo lung fibroblasts (HEL 299). Whilst both extracts did not show any inhibitory activity against neither Gram positive nor Gram negative bacteria, a strong antifungal activity was detected, in particular for the bulb extract. All clinical isolates were susceptible to the growth inhibitory activity of the bulb extract, with endpoint IC50 values ranging from 1.22 to 78 μg/mL. The pure alkaloids lycorine and vittatine, identified as components of the extract, were also assayed for their capacity of inhibiting the yeast growth, and lycorine turned very active, with endpoint IC50 values ranging from 0.89 to 28.5 μg/mL. A potent inhibition of the in vitro collagenase activity was found in the presence of the bulb extract, and this effect was much higher than that exerted by the pure alkaloids. Viability of cell lines tested was not affected by the extract. Taken together, results suggest that the extract of Pancratium illyricum may act as antifungal agent both directly on the yeast

  14. Melittin induces apoptotic features in Candida albicans

    SciTech Connect

    Park, Cana; Lee, Dong Gun

    2010-03-26

    Melittin is a well-known antimicrobial peptide with membrane-active mechanisms. In this study, it was found that Melittin exerted its antifungal effect via apoptosis. Candida albicans exposed to Melittin showed the increased reactive oxygen species (ROS) production, measured by DHR-123 staining. Fluorescence microscopy staining with FITC-annexin V, TUNEL and DAPI further confirmed diagnostic markers of yeast apoptosis including phosphatidylserine externalization, and DNA and nuclear fragmentation. The current study suggests that Melittin possesses an antifungal effect with another mechanism promoting apoptosis.

  15. Electron Microscopy of Young Candida albicans Chlamydospores

    PubMed Central

    Miller, Sara E.; Spurlock, Ben O.; Michaels, G. E.

    1974-01-01

    One- to three-day-old cultures of Candida albicans bearing chlamydospores were grown and harvested by a special technique, free of agar, and prepared for ultramicrotomy and electron microscopy. These young chlamydospores exhibited a subcellular structure similar to that of the yeast phase, e.g., cytoplasmic membrane, ribosomes, and mitochondria. Other structural characteristics unique to chlamydospores were a very thick, layered cell wall, the outer layer of which was continuous with the outer layer of the suspensor cell wall and was covered by hair-like projections; membrane bound organelles; and large lipoid inclusions. Only young chlamydospores less than 3 to 4 days old exhibited these ultrastructural characteristics. Images PMID:4368664

  16. Candida albicans in oral biofilms could prevent caries.

    PubMed

    Willems, Hubertine Marjoleine; Kos, Kevin; Jabra-Rizk, Mary Ann; Krom, Bastiaan P

    2016-07-01

    Streptococcus mutans is a Gram-positive bacterium involved in development to caries, the most common infectious disease of our time. Streptococcus mutans interacts with other microbes, like the fungus Candida albicans and both are commonly isolated from patients with caries. Since the role of C. albicans in caries remains unknown, our aim was to unravel this using an in vitro dual-species cariogenic oral biofilm model. Biofilms were grown for 24-72 h on glass cover slips or hydroxyapatite (HA) disks to mimic the surface of teeth. Medium pH, lactic acid production capacity and calcium release from HA disks were determined. All 24-h biofilms had external pH values below the critical pH of 5.5 where enamel dissolves. In contrast, 72-h dual-species biofilms had significantly higher pH (above the critical pH) and consequently decreased calcium release compared to single-species S. mutans biofilms. Counter intuitively, lactic acid production and growth of S. mutans were increased in 72-h dual-species biofilms. Candida albicans modulates the pH in dual-species biofilms to values above the critical pH where enamel dissolves. Our results suggest that C. albicans is not by definition a cariogenic microorganism; it could prevent caries by actively increasing pH preventing mineral loss. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Occurrence rate of oral Candida albicans in denture wearer patients.

    PubMed

    Daniluk, T; Tokajuk, G; Stokowska, W; Fiedoruk, K; Sciepuk, M; Zaremba, M L; Rozkiewicz, D; Cylwik-Rokicka, D; Kedra, B A; Anielska, I; Górska, M; Kedra, B R

    2006-01-01

    The aim was to determine the fungi occurrence rate in the oral cavity of denture wearer patients in comparison to those without dentures. The examinations were conducted in patients treated in two clinical departments of the University Hospital. Demographic data and those connected with basic diseases were collected and the evaluation concerning dentition and oral hygiene was performed. Samples for mycological examinations from the tongue dorsa, palatal mucosa, and mucosal surfaces of dentures were collected from patients with dentures while tongue and palate swabs were taken from those without dentures. For culture and identify of fungi standard methods were used. Dental and mycological examinations were performed in 95 patients, out of which 57 (60.0%) used complete or partial dentures and 38 (40.0%) had their own dentition (without dentures). Oral cavity revealed only growth of Candida albicans species, more frequently in patients with dentures (38/57; 66.7%) than in those without dentures (11/ 38; 28.9%) (p = 0.0003). C. albicans statistically significantly more frequently was isolated in denture wearer patients with diabetes mellitus (p = 0.0207) and without diabetes (p = 0.0376) comparing to such groups of patients but without dentures. Among 32 patients with diabetes mellitus, 14 (43.8%) revealed C. albicans; this rate was comparable with 9/23 (39.1%) patients without diabetes (p > 0.05). A similar analysis, conducted in 25 surgical patients with abdominal cancer and 15--without--cancers, did not show statistically significant differences in the incidence rate of C. albicans; it also concerned denture wearers (14/16; 87.5%) and non-wearing dentures (5/9; 55.6%) (p > 0.05) with cancer. In 37 (64.9%) wearer patients denture stomatitis was observed, associated mainly with C. albicans infections (29/37; 78.4%). 1) Mycological findings from the present study do not indicate that diabetes mellitus or advanced cancer has a significant effect on oral colonisation by

  18. Enhanced extracellular production of aspartyl proteinase, a virulence factor, by Candida albicans isolates following growth in subinhibitory concentrations of fluconazole.

    PubMed

    Wu, T; Wright, K; Hurst, S F; Morrison, C J

    2000-05-01

    We examined the production of secreted aspartyl proteinase (Sap), a putative virulence factor of Candida albicans, by a series of 17 isolates representing a single strain obtained from the oral cavity of an AIDS patient before and after the development of clinical and in vitro resistance to fluconazole. Isolates were grown in Sap-inducing yeast carbon base-bovine serum albumin medium containing 0, 0.25, 0.5, or 1 MIC of fluconazole, and cultures were sampled daily for 14 days to determine extracellular Sap activity by enzymatic degradation of bovine serum albumin. Extracellular Sap activity was significantly decreased in a dose-dependent manner for the most fluconazole-susceptible isolate (MIC, 1.0 microg/ml) and significantly increased in a dose-dependent manner for the most fluconazole-resistant isolate (MIC, >64 microg/ml). Enhanced extracellular Sap production could not be attributed to cell death or nonspecific release of Sap, because there was no reduction in the number of CFU and no significant release of enolase, a constitutive enzyme of the glycolytic pathway. Conversely, intracellular Sap concentrations were significantly increased in a dose-dependent manner in the most fluconazole-susceptible isolate and decreased in the most fluconazole-resistant isolate. Enhanced Sap production correlated with the overexpression of a gene encoding a multidrug resistance (MDR1) efflux pump occurring in these isolates. These data indicate that exposure to subinhibitory concentrations of fluconazole can result in enhanced extracellular production of Sap by isolates with the capacity to overexpress MDR1 and imply that patients infected with these isolates and subsequently treated with suboptimal doses of fluconazole may experience enhanced C. albicans virulence in vivo.

  19. Polymicrobial biofilm formation by Candida albicans, Actinomyces naeslundii, and Streptococcus mutans is Candida albicans strain and medium dependent.

    PubMed

    Arzmi, Mohd Hafiz; Alnuaimi, Ali D; Dashper, Stuart; Cirillo, Nicola; Reynolds, Eric C; McCullough, Michael

    2016-11-01

    Oral biofilms comprise of extracellular polysaccharides and polymicrobial microorganisms. The objective of this study was to determine the effect of polymicrobial interactions of Candida albicans, Actinomyces naeslundii, and Streptococcus mutans on biofilm formation with the hypotheses that biofilm biomass and metabolic activity are both C. albicans strain and growth medium dependent. To study monospecific biofilms, C. albicans, A. naeslundii, and S. mutans were inoculated into artificial saliva medium (ASM) and RPMI-1640 in separate vials, whereas to study polymicrobial biofilm formation, the inoculum containing microorganisms was prepared in the same vial prior inoculation into a 96-well plate followed by 72 hours incubation. Finally, biofilm biomass and metabolic activity were measured using crystal violet and XTT assays, respectively. Our results showed variability of monospecies and polymicrobial biofilm biomass between C. albicans strains and growth medium. Based on cut-offs, out of 32, seven RPMI-grown biofilms had high biofilm biomass (HBB), whereas, in ASM-grown biofilms, 14 out of 32 were HBB. Of the 32 biofilms grown in RPMI-1640, 21 were high metabolic activity (HMA), whereas in ASM, there was no biofilm had HMA. Significant differences were observed between ASM and RPMI-grown biofilms with respect to metabolic activity (P <01). In conclusion, biofilm biomass and metabolic activity were both C. albicans strain and growth medium dependent. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Septin Function in Candida albicans MorphogenesisD⃞

    PubMed Central

    Warenda, Amy J.; Konopka, James B.

    2002-01-01

    The septin proteins function in the formation of septa, mating projections, and spores in Saccharomyces cerevisiae, as well as in cell division and other processes in animal cells. Candida albicans septins were examined in this study for their roles in morphogenesis of this multimorphic, opportunistically pathogenic fungus, which can range from round budding yeast to elongated hyphae. C. albicans green fluorescent protein labeled septin proteins localized to a tight ring at the bud and pseudohyphae necks and as a more diffuse array in emerging germ tubes of hyphae. Deletion analysis demonstrated that the C. albicans homologs of the S. cerevisiae CDC3 and CDC12 septins are essential for viability. In contrast, the C. albicans cdc10Δ and cdc11Δ mutants were viable but displayed conditional defects in cytokinesis, localization of cell wall chitin, and bud morphology. The mutant phenotypes were not identical, however, indicating that these septins carry out distinct functions. The viable septin mutants could be stimulated to undergo hyphal morphogenesis but formed hyphae with abnormal curvature, and they differed from wild type in the selection of sites for subsequent rounds of hyphal formation. The cdc11Δ mutants were also defective for invasive growth when embedded in agar. These results further extend the known roles of the septins by demonstrating that they are essential for the proper morphogenesis of C. albicans during both budding and filamentous growth. PMID:12181342

  1. Ocimum sanctum essential oil inhibits virulence attributes in Candida albicans.

    PubMed

    Khan, Amber; Ahmad, Aijaz; Xess, Immaculata; Khan, Luqman A; Manzoor, Nikhat

    2014-03-15

    Candida albicans is an opportunistic human fungal pathogen which causes disease mainly in immunocompromised patients. Activity of hydrolytic enzymes is essential for virulence of C. albicans and so is the capacity of these cells to undergo transition from yeast to mycelial form of growth. Ocimum sanctum is cultivated worldwide for its essential oil which exhibits medicinal properties. This work evaluates the anti-virulence activity of O. sanctum essential oil (OSEO) on 22 strains of C. albicans (including a standard strain ATCC 90028) isolated from both HIV positive and HIV negative patients. Candida isolates were exposed to sub-MICs of OSEO. In vitro secretion of proteinases and phospholipases was evaluated by plate assay containing BSA and egg yolk respectively. Morphological transition from yeast to filamentous form was monitored microscopically in LSM. For genetic analysis, respective genes associated with morphological transition (HWP1), proteinase (SAP1) and phospholipase (PLB2) were also investigated by Real Time PCR (qRT-PCR). Results were analyzed using Student's t-test. OSEO inhibits morphological transition in C. albicans and had a significant inhibitory effect on extracellular secretion of proteinases and phospholipases. Expression profile of respective selected genes associated with C. albicans virulence by qRT-PCR showed a reduced expression of HWP1, SAP1 and PLB2 genes in cells treated with sub-inhibitory concentrations of OSEO. This work suggests that OSEO inhibits morphological transition in C. albicans and decreases the secretion of hydrolytic enzymes involved in the early stage of infection as well as down regulates the associated genes. Further studies will assess the clinical application of OSEO and its constituents in the treatment of fungal infections.

  2. Candida albicans susceptibility to lactoperoxidase-generated hypoiodite

    PubMed Central

    Ahariz, Mohamed; Courtois, Philippe

    2010-01-01

    In vivo, lactoperoxidase produces hypothiocyanite (OSCN−) from thiocyanate (SCN−) in the presence of hydrogen peroxide (H2O2); in vitro, iodide (I−) can be oxidized into hypoiodite (OI−) by this enzyme. The aim of this study was to compare in vitro the anti-Candida effect of iodide versus thiocyanate used as lactoperoxidase substrate to prevent Candida biofilms development. Candida albicans ATCC 10231 susceptibility upon both peroxidase systems was tested in three different experimental designs: (i) in a liquid culture medium, (ii) in an interface model between solid culture medium and gel containing the enzymic systems, (iii) in a biofilm model onto titanium and acrylic resin. Yeast growth in liquid medium was monitored by turbidimetry at 600 nm. Material-adherent yeast biomass was evaluated by the tetrazolium salt MTT method. The iodide-peroxidase system has been shown to inhibit Candida biofilm formation at lower substrate concentrations (~200 fold less H2O2 donor) and for longer incubation periods than the thiocyanate-peroxidase system. In conclusion, efficiency of lactoperoxidase-generated OI− to prevent C. albicans biofilm development allows refining iodine antifungal use in ex vivo conditions. PMID:23662084

  3. Influence of sucrose on growth and sensitivity of Candida albicans alone and in combination with Enterococcus faecalis and Streptococcus mutans to photodynamic therapy.

    PubMed

    Tomé, Fernanda Malagutti; Paula Ramos, Lucas De; Freire, Fernanda; Pereira, Cristiane Aparecida; de Oliveira, Ingrid Christine Barbosa; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso; Oliveira, Luciane Dias de

    2017-08-01

    This study has evaluated the effects of photodynamic inactivation (PDI) using erythrosine as photosensitizer and green light-emitting diode (LED) on biofilms of Candida albicans alone and in combination with Enterococcus faecalis and Streptococcus mutans. We have also evaluated the effect of sucrose on biofilm formation and bacterial growth and sensitivity to PDI. Biofilms were formed in suspension of 10(6) cells/ml on plates before being grown in broth culture with and without sucrose and incubated for 48 h. Next, the treatment was applied using erythrosine at a concentration of 400 μM for 5 min and green LED (532 ± 10 nm) for 3 min on biofilms alone and in combination. The plates were washed and sonicated to disperse the biofilms, and serial dilutions were carried and aliquots seeded in Sabouraud agar before incubation for 48 h. Next, the colony-forming units per milliliter (CFU/ml; log10) were counted and analyzed statistically (ANOVA, Tukey test, P ≤ 0.05). Results show that S. mutans favors the growth of C. albicans in biofilms with sucrose, with treatment not being effective. However, when the biofilm was grown without sucrose, we found a reduction in biofilm formation and a significant decrease in the PDI treatment (P < 0.0001). In conclusion, both growth and sensitivity to PDI in biofilms of C. albicans are strongly influenced by bacterial combination, and the presence of sucrose affected directly the growth and sensitivity of the biofilm to PDI as sucrose is the substrate for construction of the exopolysaccharide matrix.

  4. Antimicrobial activity of plant extracts on Candida albicans: an in vitro study.

    PubMed

    Doddanna, Sunitha Jagalur; Patel, Shilpa; Sundarrao, Madhusudan Astekar; Veerabhadrappa, Ravindra Setru

    2013-01-01

    Plants as sources of medicinal compounds have continued to play a predominant role in the maintenance of human health since ancient times. Even though several effective antifungal agents are available for oral candida infections, the failure is not uncommon because isolates of Candida albicans may exhibits resistance to the drug during therapy. The present study was conducted to evaluate the antimicrobial effects of few plant extracts on Candida albicans. An additional objective was to identify an alternative, inexpensive, simple, and effective method of preventing and controlling Candida albicans. Fine texture powder or paste form of leaves was soaked in sterile distilled water and 100% ethyl alcohol, which were kept in refrigerator at 4°C for 24 h. Then filtrates were prepared and kept in a hot air oven to get a black shining crystal powder/paste form. Stock solutions of plant extracts were inoculated on petri plates containing species of Candida albicans and incubated at 25 ± 2°C for 72 h. Alcoholic curry leaves showed the maximum zone of inhibition on Candida albicans followed by aqueous tea leaves. The other plant extracts like alcoholic onion leaves, alcoholic tea leaves, alcoholic onion bulb, alcoholic aloe vera, and alcoholic mint leaves also inhibited the growth of Candida albicans but lesser extent. The present study renders few medicinal plants as an alternative medicines to the field of dentistry which can be used adjunct to conventional therapy of oral candidasis.

  5. Triclosan Antagonizes Fluconazole Activity against Candida albicans

    PubMed Central

    Higgins, J.; Pinjon, E.; Oltean, H.N.; White, T.C.; Kelly, S.L.; Martel, C.M.; Sullivan, D.J.; Coleman, D.C.; Moran, G.P.

    2012-01-01

    Triclosan is a broad-spectrum antimicrobial compound commonly used in oral hygiene products. Investigation of its activity against Candida albicans showed that triclosan was fungicidal at concentrations of 16 mg/L. However, at subinhibitory concentrations (0.5-2 mg/L), triclosan antagonized the activity of fluconazole. Although triclosan induced CDR1 expression in C. albicans, antagonism was still observed in cdr1Δ and cdr2Δ strains. Triclosan did not affect fluconazole uptake or alter total membrane sterol content, but did induce the expression of FAS1 and FAS2, indicating that its mode of action may involve inhibition of fatty acid synthesis, as it does in prokaryotes. However, FAS2 mutants did not exhibit increased susceptibility to triclosan, and overexpression of both FAS1 and FAS2 alleles did not alter triclosan susceptibility. Unexpectedly, the antagonistic effect was specific for C. albicans under hypha-inducing conditions and was absent in the non-filamentous efg1Δ strain. This antagonism may be due to the membranotropic activity of triclosan and the unique composition of hyphal membranes. PMID:21972257

  6. Nicotine Enhances Interspecies Relationship between Streptococcus mutans and Candida albicans.

    PubMed

    Liu, Shiyu; Qiu, Wei; Zhang, Keke; Zhou, Xuedong; Ren, Biao; He, Jinzhi; Xu, Xin; Cheng, Lei; Li, Mingyun

    2017-01-01

    Streptococcus mutans and Candida albicans are common microorganisms in the human oral cavity. The synergistic relationship between these two species has been deeply explored in many studies. In the present study, the effect of alkaloid nicotine on the interspecies between S. mutans and C. albicans is explored. We developed a dual-species biofilm model and studied biofilm biomass, biofilm structure, synthesis of extracellular polysaccharides (EPS), and expression of glucosyltransferases (Gtfs). Biofilm formation and bacterial and fungal cell numbers in dual-species biofilms increased in the presence of nicotine. More C. albicans cells were present in the dual-species biofilms in the nicotine-treated groups as determined by scanning electron microscopy. The synthesis of EPS was increased by 1 mg/ml of nicotine as detected by confocal laser scanning microscopy. The result of qRT-PCR showed gtfs expression was upregulated when 1 mg/ml of nicotine was used. We speculate that nicotine promoted the growth of S. mutans, and more S. mutans cells attracted more C. albicans cells due to the interaction between two species. Since S. mutans and C. albicans are putative pathogens for dental caries, the enhancement of the synergistic relationship by nicotine may contribute to caries development in smokers.

  7. Nicotine Enhances Interspecies Relationship between Streptococcus mutans and Candida albicans

    PubMed Central

    Qiu, Wei; Zhang, Keke; Zhou, Xuedong; Ren, Biao; He, Jinzhi; Xu, Xin

    2017-01-01

    Streptococcus mutans and Candida albicans are common microorganisms in the human oral cavity. The synergistic relationship between these two species has been deeply explored in many studies. In the present study, the effect of alkaloid nicotine on the interspecies between S. mutans and C. albicans is explored. We developed a dual-species biofilm model and studied biofilm biomass, biofilm structure, synthesis of extracellular polysaccharides (EPS), and expression of glucosyltransferases (Gtfs). Biofilm formation and bacterial and fungal cell numbers in dual-species biofilms increased in the presence of nicotine. More C. albicans cells were present in the dual-species biofilms in the nicotine-treated groups as determined by scanning electron microscopy. The synthesis of EPS was increased by 1 mg/ml of nicotine as detected by confocal laser scanning microscopy. The result of qRT-PCR showed gtfs expression was upregulated when 1 mg/ml of nicotine was used. We speculate that nicotine promoted the growth of S. mutans, and more S. mutans cells attracted more C. albicans cells due to the interaction between two species. Since S. mutans and C. albicans are putative pathogens for dental caries, the enhancement of the synergistic relationship by nicotine may contribute to caries development in smokers. PMID:28280743

  8. Interplay between Candida albicans and the Mammalian Innate Host Defense

    PubMed Central

    Cheng, Shih-Chin; Joosten, Leo A. B.; Kullberg, Bart-Jan

    2012-01-01

    Candida albicans is both the most common fungal commensal microorganism in healthy individuals and the major fungal pathogen causing high mortality in at-risk populations, especially immunocompromised patients. In this review, we summarize the interplay between the host innate system and C. albicans, ranging from how the host recognizes, responds, and clears C. albicans infection to how C. albicans evades, dampens, and escapes from host innate immunity. PMID:22252867

  9. Looking into Candida albicans infection, host response, and antifungal strategies.

    PubMed

    Wang, Yan

    2015-01-01

    Candida albicans, a commonly encountered fungal pathogen, causes diseases varying from superficial mucosal complaints to life-threatening systemic disorders. Among the virulence traits of C. albicans, yeast-to-hypha transition is most widely acknowledged. Host innate immunity to C. albicans critically requires pattern recognition receptors (PRRs), and defence against C. albicans infection is provided by an exquisite interplay between the innate and adaptive arms of the host immune system.

  10. Looking into Candida albicans infection, host response, and antifungal strategies

    PubMed Central

    Wang, Yan

    2015-01-01

    Candida albicans, a commonly encountered fungal pathogen, causes diseases varying from superficial mucosal complaints to life-threatening systemic disorders. Among the virulence traits of C. albicans, yeast-to-hypha transition is most widely acknowledged. Host innate immunity to C. albicans critically requires pattern recognition receptors (PRRs), and defence against C. albicans infection is provided by an exquisite interplay between the innate and adaptive arms of the host immune system. PMID:25590793

  11. Germ tube-specific antigens of Candida albicans cell walls

    SciTech Connect

    Sundstrom, P.R.

    1986-01-01

    Studies were performed to characterize the surface differences between blastospores and germ tubes of the pathogenic, dimorphic yeast, Candida albicans, and to identify components of yeast cells responsible for these differences. Investigation of surfaces differences of the two growth forms was facilitated by the production of rabbit antiserum prepared against Formalin-treated yeast possessing germ tubes. To prepare antiserum specific for germ tubes, this serum was adsorbed with stationary phase blastospores. Whereas the unadsorbed antiserum reacted with both blastospore and germ tube forms by immunofluorescence and Enzyme-Linked Immunosorbent Assay, the adsorbed antiserum did not react with blastospores but detected germ tube-specific antigens in hyphal forms. The differences between blastospores and germ tubes of Candida albicans, were further studied by comparing enzymatic digests of cell walls of both growth forms in radiolabeled organisms. Organisms were labeled either on the surface with /sup 125/I, or metabolically with (/sup 35/S) methionine or (/sup 3/H) mannose. Three-surface-located components (as shown by antibody adsorption and elution experiments) were precipitated from Zymolase digests. All three components were mannoproteins as shown by their ability to bind Concanavalin A, and to be labeled in protein labeling procedures, and two of these (200,000 and 155,000 molecular weight) were germ tube specific, as shown by their ability to be precipitated by germ tube-specific antiserum. Monoclonal antibodies were prepared to C. albicans, using blastospores bearing germ tubes as immunogen.

  12. Conserved and Divergent Roles of Bcr1 and CFEM Proteins in Candida parapsilosis and Candida albicans

    PubMed Central

    Maguire, Sarah L.; Guida, Alessandro; Synnott, John M.; Andes, David R.; Butler, Geraldine

    2011-01-01

    Candida parapsilosis is a pathogenic fungus that is major cause of hospital-acquired infection, predominantly due to growth as biofilms on indwelling medical devices. It is related to Candida albicans, which remains the most common cause of candidiasis disease in humans. The transcription factor Bcr1 is an important regulator of biofilm formation in vitro in both C. parapsilosis and C. albicans. We show here that C. parapsilosis Bcr1 is required for in vivo biofilm development in a rat catheter model, like C. albicans. By comparing the transcription profiles of a bcr1 deletion in both species we found that regulation of expression of the CFEM family is conserved. In C. albicans, three of the five CFEM cell wall proteins (Rbt5, Pga7 and Csa1) are associated with both biofilm formation and acquisition of iron from heme, which is an important virulence characteristic. In C. parapsilosis, the CFEM family has undergone an expansion to 7 members. Expression of three genes (CFEM2, CFEM3, and CFEM6) is dependent on Bcr1, and is induced in low iron conditions. All three are involved in the acquisition of iron from heme. However, deletion of the three CFEM genes has no effect on biofilm formation in C. parapsilosis. Our data suggest that the role of the CFEM family in iron acquisition is conserved between C. albicans and C. parapsilosis, but their role in biofilm formation is not. PMID:22145027

  13. Direct electrochemical determination of Candida albicans activity.

    PubMed

    Hassan, Rabeay Y A; Bilitewski, Ursula

    2013-11-15

    Despite advances made in the field, rapid detection methods for the human pathogen Candida albicans are still missing. In this regard, bio-electrochemical systems including electrochemical sensors and biosensors satisfy the increasing demand for rapid, reliable, and direct microbial analyses. In this study, the bioelectrochemical characteristics of C. albicans were investigated for use in an analytical system that determines the viability of the organisms. The electrochemical responses of viable and non-viable cells of C. albicans and Saccharomyces cerevisiae were monitored. Cyclic voltammograms (CV) showed an irreversible oxidation peak at about 750 mV that accounts for viable cells. The peak current increased at viable cell numbers ranging from 3 × 10(5) to 1.6 × 10(7)cells/ml, indicating that the amount of viable cells can be accurately quantified. To elucidate the underlying electron transfer processes, the influence of electron transfer chain (ETC) - inhibitors on the electrochemical behavior of the two organisms were investigated. Inhibition of the function of classical respiratory chain (CRC) led to a decrease in the electrochemical response, whereas the oxidation current increased when the alternative oxidase (AOX) pathway was blocked by salicylhydroxamic acid (SHA). Blocking the AOX pathway improved the electrochemical performance, suggesting an involvement in the CRC, with cytochrome c oxidase (COX) as a relevant protein complex. Mutants, in which components of COX were deleted, showed a lower electro-activity than the wild-type strain. Particularly, deletion of subunit COX5a almost completely abolished the electrochemical signal. We believe that this work can be utilized for the development of early detection assays and opens the door for new technological developments in the field of C. albicans.

  14. In vitro efficacy of liposomal amphotericin B, micafungin and fluconazole against non-albicans Candida species biofilms.

    PubMed

    Kawai, Akira; Yamagishi, Yuka; Mikamo, Hiroshige

    2015-09-01

    Non-albicans Candida species are being isolated with increasing frequency. In this study, biofilm formation by Candida tropicalis, Candida parapsilosis and Candida glabrata was evaluated and the activities of liposomal amphotericin B (LAB), micafungin (MFG) and fluconazole (FLC) against these biofilms were assessed using a clinically relevant in vitro model system. LAB exhibited strong activities against the three non-albicans Candida species and showed dose-dependent efficacy. MFG displayed a paradoxical growth effect against the C. tropicalis biofilm. FLC was ineffective for non-albicans biofilms. This study shows that Candida biofilms have unique susceptibility to LAB. The dose-dependent effects of LAB indicate that this drug may be a useful treatment for biofilm formation by non-albicans Candida species in cases in which the catheter cannot be removed for clinical reasons.

  15. Comparison of the clinical risk factors between Candida albicans and Candida non-albicans species for bloodstream infection.

    PubMed

    Shigemura, Katsumi; Osawa, Kayo; Jikimoto, Takumi; Yoshida, Hiroyuki; Hayama, Brian; Ohji, Goh; Iwata, Kentaro; Fujisawa, Masato; Arakawa, Soichi

    2014-04-01

    The purpose of this study is to investigate the risk factors and susceptibilities to antifungal agents of Candida albicans and Candida non-albicans species (spp.) in candidemia cases in Kobe University Hospital. We investigated all consecutive patients with candida bloodstream infection (BSI) from 2008-2013 for whose full data were available for analyses, examining clinical factors such as gender, general complications, postoperative status or susceptibilities to antifungal agents. These factors were also compared between Candida albicans spp. and Candida non-albicans by univariate and multivariate analyses. Univariate analyses showed a significantly higher rate of Candida non-albicans species BSI patients cancer (odds ratio (OR) (95% confidence interval (CI))=2.29 (1.04-5.06) and P=0.040), chemotherapy (OR=4.35 (1.11-17.1) and P=0.035), fluconazole (FLCZ) resistance (OR=77.3 (4.51-1324) and P=0.003), and itraconazole (ITCZ) resistance (OR=15.6 (5.39-45.1) and P<0.001) and lower rate of underlying cardiovascular diseases (OR=0.27 (0.09-0.80) and P=0.018) and postoperative status (OR=0.35 (0.16-0.77) and P=0.035) in than Candida albicans. Multivariate analyses demonstrated that Candida non-albicans spp. had significantly higher rate of chemotherapy (OR=4.44 (1.04-19.0) and P=0.045), FLCZ resistance (OR=5.87 (2.01-17.1) and P=0.001), and ITCZ resistance (OR=18.7(5.77-60.4) and P<0.001) and lower rate of underlying cardiovascular diseases (OR=0.25 (0.08-0.82) and P=0.022) than Candida albicans. In conclusion, this study revealed several risk factors for BSI with Candida albicans (underlying cardiovascular diseases and postoperative status) and Candida non-albicans spp. (cancer and chemotherapy), and demonstrated that Candida non-albicans spp. were more resistant to FLCZ and ITCZ than Candida albicans.

  16. Candida albicans biofilm on titanium: effect of peroxidase precoating

    PubMed Central

    Ahariz, Mohamed; Courtois, Philippe

    2010-01-01

    The present study aimed to document Candida albicans biofilm development on titanium and its modulation by a peroxidase-precoated material which can generate antimicrobials, such as hypoiodite or hypothiocyanite, from hydrogen peroxide, iodide, or thiocyanate. For this purpose, titanium (powder or foil) was suspended in Sabouraud liquid medium inoculated with C. albicans ATCC10231. After continuous stirring for 2–21 days at room temperature, the supernatant was monitored by turbidimetry at 600 nm and titanium washed three times in sterile Sabouraud broth. Using the tetrazolium salt MTT-formazan assay, the titanium-adherent fungal biomass was measured as 7.50 ± 0.60 × 106 blastoconidia per gram of titanium powder (n = 30) and 0.50 ± 0.04 × 106 blastoconidia per cm2 of titanium foil (n = 12). The presence of yeast on the surface of titanium was confirmed by microscopy both on fresh preparations and after calcofluor white staining. However, in the presence of peroxidase systems (lactoperoxidase with substrates such as hydrogen peroxide donor, iodide, or thiocyanate), Candida growth in both planktonic and attached phases appeared to be inhibited. Moreover, this study demonstrates the possible partition of peroxidase systems between titanium material (peroxidase-precoated) and liquid environment (containing peroxidase substrates) to limit C. albicans biofilm formation. PMID:22915919

  17. Denture disinfection by microwave energy: influence of Candida albicans biofilm.

    PubMed

    Senna, Plínio Mendes; da Silva, Wander José; Cury, Altair Antoninha Del Bel

    2012-06-01

    This study evaluated the influence of the area of Candida albicans biofilm on denture disinfection by microwave energy. Candida albicans biofilm was allowed to form for 72 h on resin discs, and three small coverage or seven large coverage discs were placed onto the palatal surface of sterile maxillary dentures. Each denture was immersed in 200 ml distilled water and individually irradiated at a power of 450, 630 or 900 W for different time intervals (1, 2 or 3 min) (n = 6). The effectiveness of disinfection was evaluated by counting the residual cells. The data were analysed by anova and Tukey's HSD test (α = 0.05). Pearson's correlation test was performed to determine the correlation between effectiveness of sterilisation and temperature. Dentures with a larger area of biofilm demanded a longer irradiation exposure to achieve disinfection (p < 0.001), irrespective of power setting, and in this time no yeast growth was detected. Dentures with small areas of biofilm were disinfected after 1 min at 900 W and 2 min at 450 or 630 W. A positive correlation was found between water temperature and effectiveness of disinfection (r = 0.6170; p < 0.001). The C. albicans biofilm area influenced disinfection by microwave energy; therefore dentures with larger biofilm areas required longer irradiation exposure to be disinfected. © 2010 The Gerodontology Society and John Wiley & Sons A/S.

  18. Comparative Phenotypic Analysis of the Major Fungal Pathogens Candida parapsilosis and Candida albicans

    PubMed Central

    Holland, Linda M.; Schröder, Markus S.; Turner, Siobhán A.; Taff, Heather; Andes, David; Grózer, Zsuzsanna; Gácser, Attila; Ames, Lauren; Haynes, Ken; Higgins, Desmond G.; Butler, Geraldine

    2014-01-01

    Candida parapsilosis and Candida albicans are human fungal pathogens that belong to the CTG clade in the Saccharomycotina. In contrast to C. albicans, relatively little is known about the virulence properties of C. parapsilosis, a pathogen particularly associated with infections of premature neonates. We describe here the construction of C. parapsilosis strains carrying double allele deletions of 100 transcription factors, protein kinases and species-specific genes. Two independent deletions were constructed for each target gene. Growth in >40 conditions was tested, including carbon source, temperature, and the presence of antifungal drugs. The phenotypes were compared to C. albicans strains with deletions of orthologous transcription factors. We found that many phenotypes are shared between the two species, such as the role of Upc2 as a regulator of azole resistance, and of CAP1 in the oxidative stress response. Others are unique to one species. For example, Cph2 plays a role in the hypoxic response in C. parapsilosis but not in C. albicans. We found extensive divergence between the biofilm regulators of the two species. We identified seven transcription factors and one protein kinase that are required for biofilm development in C. parapsilosis. Only three (Efg1, Bcr1 and Ace2) have similar effects on C. albicans biofilms, whereas Cph2, Czf1, Gzf3 and Ume6 have major roles in C. parapsilosis only. Two transcription factors (Brg1 and Tec1) with well-characterized roles in biofilm formation in C. albicans do not have the same function in C. parapsilosis. We also compared the transcription profile of C. parapsilosis and C. albicans biofilms. Our analysis suggests the processes shared between the two species are predominantly metabolic, and that Cph2 and Bcr1 are major biofilm regulators in C. parapsilosis. PMID:25233198

  19. Comparative phenotypic analysis of the major fungal pathogens Candida parapsilosis and Candida albicans.

    PubMed

    Holland, Linda M; Schröder, Markus S; Turner, Siobhán A; Taff, Heather; Andes, David; Grózer, Zsuzsanna; Gácser, Attila; Ames, Lauren; Haynes, Ken; Higgins, Desmond G; Butler, Geraldine

    2014-09-01

    Candida parapsilosis and Candida albicans are human fungal pathogens that belong to the CTG clade in the Saccharomycotina. In contrast to C. albicans, relatively little is known about the virulence properties of C. parapsilosis, a pathogen particularly associated with infections of premature neonates. We describe here the construction of C. parapsilosis strains carrying double allele deletions of 100 transcription factors, protein kinases and species-specific genes. Two independent deletions were constructed for each target gene. Growth in >40 conditions was tested, including carbon source, temperature, and the presence of antifungal drugs. The phenotypes were compared to C. albicans strains with deletions of orthologous transcription factors. We found that many phenotypes are shared between the two species, such as the role of Upc2 as a regulator of azole resistance, and of CAP1 in the oxidative stress response. Others are unique to one species. For example, Cph2 plays a role in the hypoxic response in C. parapsilosis but not in C. albicans. We found extensive divergence between the biofilm regulators of the two species. We identified seven transcription factors and one protein kinase that are required for biofilm development in C. parapsilosis. Only three (Efg1, Bcr1 and Ace2) have similar effects on C. albicans biofilms, whereas Cph2, Czf1, Gzf3 and Ume6 have major roles in C. parapsilosis only. Two transcription factors (Brg1 and Tec1) with well-characterized roles in biofilm formation in C. albicans do not have the same function in C. parapsilosis. We also compared the transcription profile of C. parapsilosis and C. albicans biofilms. Our analysis suggests the processes shared between the two species are predominantly metabolic, and that Cph2 and Bcr1 are major biofilm regulators in C. parapsilosis.

  20. Regulation of superoxide dismutase synthesis in Candida albicans.

    PubMed

    Gunasekaran, U; Yang, R; Gunasekaran, M

    1998-01-01

    The synthesis of superoxide dismutase [SOD: EC 1.15.1.1] in response to various cultural conditions was examined in Candida albicans, an opportunistic yeast which causes candidiasis in immunosuppressed patients. SOD plays an important role in protecting cells from teh oxidative damage of superoxide radicals. Maximum SOD activity was found after 72 hrs of yeast growth. The optimum pH and temperature for the SOD activity were 7 and 40 degrees C, respectively. The major SOD activity was found in the cytosol fraction and the level of extracellular SOD was very low. The enzyme was stimulated to varying degrees by cholic acid, procaine and tocopherol. On the basis of inhibitor studies and other enzyme properties, the isolated enzyme from C. albicans is identified as a copper and zinc superoxide dismutase.

  1. A piglet model for studying Candida albicans colonization of the human oro-gastrointestinal tract.

    PubMed

    Hoeflinger, Jennifer L; Coleman, David A; Oh, Soon-Hwan; Miller, Michael J; Hoyer, Lois L

    2014-08-01

    Pigs from a variety of sources were surveyed for oro-gastrointestinal (oro-GIT) carriage of Candida albicans. Candida albicans-positive animals were readily located, but we also identified C. albicans-free pigs. We hypothesized that pigs could be stably colonized with a C. albicans strain of choice, simply by feeding yeast cells. Piglets were farrowed routinely and remained with the sow for 4 days to acquire a normal microbiota. Piglets were then placed in an artificial rearing environment and fed sow milk replacer. Piglets were inoculated orally with one of three different C. albicans strains. Piglets were weighed daily, and culture swabs were collected to detect C. albicans orally, rectally and in the piglet's environment. Stable C. albicans colonization over the course of the study did not affect piglet growth. Necropsy revealed mucosally associated C. albicans throughout the oro-GIT with the highest abundance in the esophagus. Uninoculated control piglets remained C. albicans-negative. These data establish the piglet as a model to study C. albicans colonization of the human oro-GIT. Similarities between oro-GIT colonization in humans and pigs, as well as the ease of working with the piglet model, suggest its adaptability for use among investigators interested in understanding C. albicans-host commensal interactions.

  2. Influence of culture conditions for clinically isolated non-albicans Candida biofilm formation.

    PubMed

    Tan, Yulong; Leonhard, Matthias; Ma, Su; Schneider-Stickler, Berit

    2016-11-01

    Non-albicans Candida species have been isolated in increasing numbers in patients. Moreover, they are adept at forming biofilms. This study analyzed biofilm formation of clinically isolated non-albicans Candida, including Candida tropicalis, Candida krusei and Candida parapsilosis under the influence of different growth media (RPMI 1640, YPD and BHI) and several culture variables (inoculum concentration, incubation period and feeding conditions). The results showed that culture conditions strongly influenced non-albicans Candida species biofilm formation. YPD and BHI resulted in larger amount of biofilm formation with higher metabolic activity of biofilms. Furthermore, the growth media seems to have varying effects on adhesion and biofilm development. Growth conditions may also influence biofilm formation, which was enhanced when starting the culture with a larger inoculum, longer incubation period and using a fed-batch system. Therefore, the potential influences of external environmental factors should be considered when studying the non-albicans Candida biofilms in vitro. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Transformations of inorganic mercury by Candida albicans and Saccharomyces cerevisiae

    SciTech Connect

    Yannai, S.; Berdicevsky, I.; Duek, L. )

    1991-01-01

    Saccharomyces cerevisiae and Candida albicans were incubated with 0.25, 0.5, or 0.75 {mu}g of Hg (as HgCl{sub 2}) per ml of Nelson's medium in the presence of trace amounts of oxygen at 28{degree}C for 12 days. Two control media were used, one without added Hg and one without yeast inoculum. Yeast cell growth was estimated after 1, 2, 3, and 8 days of incubation. The contents of organomercury in the system and of elemental mercury released from the media and collected in traps were determined at the end of the experiments. The results were as follows: (1) C. albicans was the more mercury-resistant species, but both yeast species failed to grown in the media containing 0.75 {mu}g of Hg per ml.; (2) The amounts of organomercury produced by the two species were proportional to the amount of HgCl{sub 2} added to the medium. In all cases C. albicans produced considerably larger amounts of methylmercury than S. cerevisiae; (3) The amounts of elemental Hg produced were inversely proportional to the HgCl{sub 2} level added in the case of S. cerevisiae but were all similar in the case of C. albicans;and (4) Neither organomercury nor elemental Hg was produced in any of the control media.

  4. Disruption of Sphingolipid Biosynthesis Blocks Phagocytosis of Candida albicans

    PubMed Central

    Schmidt, Florian I.; Freinkman, Elizaveta; Dougan, Stephanie; Dougan, Michael; Esteban, Alexandre; Maruyama, Takeshi; Strijbis, Karin; Ploegh, Hidde L.

    2015-01-01

    The ability of phagocytes to clear pathogens is an essential attribute of the innate immune response. The role of signaling lipid molecules such as phosphoinositides is well established, but the role of membrane sphingolipids in phagocytosis is largely unknown. Using a genetic approach and small molecule inhibitors, we show that phagocytosis of Candida albicans requires an intact sphingolipid biosynthetic pathway. Blockade of serine-palmitoyltransferase (SPT) and ceramide synthase-enzymes involved in sphingolipid biosynthesis- by myriocin and fumonisin B1, respectively, impaired phagocytosis by phagocytes. We used CRISPR/Cas9-mediated genome editing to generate Sptlc2-deficient DC2.4 dendritic cells, which lack serine palmitoyl transferase activity. Sptlc2-/- DC2.4 cells exhibited a stark defect in phagocytosis, were unable to bind fungal particles and failed to form a normal phagocytic cup to engulf C. albicans. Supplementing the growth media with GM1, the major ganglioside present at the cell surface, restored phagocytic activity of Sptlc2-/- DC2.4 cells. While overall membrane trafficking and endocytic pathways remained functional, Sptlc2-/- DC2.4 cells express reduced levels of the pattern recognition receptors Dectin-1 and TLR2 at the cell surface. Consistent with the in vitro data, compromised sphingolipid biosynthesis in mice sensitizes the animal to C. albicans infection. Sphingolipid biosynthesis is therefore critical for phagocytosis and in vivo clearance of C. albicans. PMID:26431038

  5. Disruption of Sphingolipid Biosynthesis Blocks Phagocytosis of Candida albicans.

    PubMed

    Tafesse, Fikadu G; Rashidfarrokhi, Ali; Schmidt, Florian I; Freinkman, Elizaveta; Dougan, Stephanie; Dougan, Michael; Esteban, Alexandre; Maruyama, Takeshi; Strijbis, Karin; Ploegh, Hidde L

    2015-10-01

    The ability of phagocytes to clear pathogens is an essential attribute of the innate immune response. The role of signaling lipid molecules such as phosphoinositides is well established, but the role of membrane sphingolipids in phagocytosis is largely unknown. Using a genetic approach and small molecule inhibitors, we show that phagocytosis of Candida albicans requires an intact sphingolipid biosynthetic pathway. Blockade of serine-palmitoyltransferase (SPT) and ceramide synthase-enzymes involved in sphingolipid biosynthesis- by myriocin and fumonisin B1, respectively, impaired phagocytosis by phagocytes. We used CRISPR/Cas9-mediated genome editing to generate Sptlc2-deficient DC2.4 dendritic cells, which lack serine palmitoyl transferase activity. Sptlc2-/- DC2.4 cells exhibited a stark defect in phagocytosis, were unable to bind fungal particles and failed to form a normal phagocytic cup to engulf C. albicans. Supplementing the growth media with GM1, the major ganglioside present at the cell surface, restored phagocytic activity of Sptlc2-/- DC2.4 cells. While overall membrane trafficking and endocytic pathways remained functional, Sptlc2-/- DC2.4 cells express reduced levels of the pattern recognition receptors Dectin-1 and TLR2 at the cell surface. Consistent with the in vitro data, compromised sphingolipid biosynthesis in mice sensitizes the animal to C. albicans infection. Sphingolipid biosynthesis is therefore critical for phagocytosis and in vivo clearance of C. albicans.

  6. Hydrophobic polyoxins are resistant to intracellular degradation in Candida albicans.

    PubMed Central

    Smith, H A; Shenbagamurthi, P; Naider, F; Kundu, B; Becker, J M

    1986-01-01

    Two novel polyoxins, N-epsilon-(octanoyl)-lysyl-uracil polyoxin C (Oct-Lys-UPOC) and N-gamma-(octyl)-glutaminyluracil polyoxin C (Oct-Gln-UPOC), were synthesized by reacting uracil polyoxin C with the appropriate amino acid p-nitrophenyl ester. Oct-Lys-UPOC and Oct-Gln-UPOC were strong inhibitors (Kis = 1.7 X 10(-6)M) of chitin synthetase from Candida albicans membrane preparations. In a permeabilized-cell assay, Oct-Gln-UPOC had a 10-fold-lower inhibitory activity toward chitin synthetase than did the Oct-Lys-UPOC analog. Both compounds were resistant to hydrolysis by a cell extract of C. albicans H317; however, Oct-Gln-UPOC was hydrolyzed with a half-life of 23 min by a permeabilized-cell preparation. Oct-Lys-UPOC was resistant to hydrolysis by permeabilized cells. Oct-Gln-UPOC and Oct-Lys-UPOC did not compete with the transport of peptides or uridine into the cell. At concentrations up to 2 mM these two new polyoxins were ineffective in the inhibition of cell growth or reduction of cell viability, but they induced aberrant morphologies in C. albicans at a concentration of 0.25 mM. These data suggest that polyoxins containing hydrophobic amino acids retain strong chitin synthetase inhibitory activity and are resistant to cellular hydrolysis. They provide the first example of effective synthetic chitin synthetase inhibitors which are stable inside C. albicans. PMID:3524423

  7. Budding off: bringing functional genomics to Candida albicans

    PubMed Central

    Anderson, Matthew Z.

    2016-01-01

    Candida species are the most prevalent human fungal pathogens, with Candida albicans being the most clinically relevant species. Candida albicans resides as a commensal of the human gastrointestinal tract but is a frequent cause of opportunistic mucosal and systemic infections. Investigation of C. albicans virulence has traditionally relied on candidate gene approaches, but recent advances in functional genomics have now facilitated global, unbiased studies of gene function. Such studies include comparative genomics (both between and within Candida species), analysis of total RNA expression, and regulation and delineation of protein–DNA interactions. Additionally, large collections of mutant strains have begun to aid systematic screening of clinically relevant phenotypes. Here, we will highlight the development of functional genomics in C. albicans and discuss the use of these approaches to addressing both commensalism and pathogenesis in this species. PMID:26424829

  8. Budding off: bringing functional genomics to Candida albicans.

    PubMed

    Anderson, Matthew Z; Bennett, Richard J

    2016-03-01

    Candida species are the most prevalent human fungal pathogens, with Candida albicans being the most clinically relevant species. Candida albicans resides as a commensal of the human gastrointestinal tract but is a frequent cause of opportunistic mucosal and systemic infections. Investigation of C. albicans virulence has traditionally relied on candidate gene approaches, but recent advances in functional genomics have now facilitated global, unbiased studies of gene function. Such studies include comparative genomics (both between and within Candida species), analysis of total RNA expression, and regulation and delineation of protein-DNA interactions. Additionally, large collections of mutant strains have begun to aid systematic screening of clinically relevant phenotypes. Here, we will highlight the development of functional genomics in C. albicans and discuss the use of these approaches to addressing both commensalism and pathogenesis in this species. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  9. Diallyl disulphide depletes glutathione in Candida albicans

    PubMed Central

    Lemar, Katey M.; Aon, Miguel A.; Cortassa, Sonia; O’Rourke, Brian; T. Müller, Carsten; Lloyd, David

    2008-01-01

    Using two-photon scanning laser microscopy, we investigated the effect of an Allium sativum (garlic) constituent, diallyl disulphide (DADS), on key physiological functions of the opportunistic pathogen Candida albicans. A short 30 min exposure to 0.5 mm DADS followed by removal induced 70% cell death (50% necrotic, 20% apoptotic) within 2 h, increasing to 75% after 4 h. The early intracellular events associated with DADS-induced cell death were monitored with two-photon fluorescence microscopy to track mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS) and NADH or reduced glutathione (GSH) under aerobic conditions. DADS treatment decreased intracellular GSH and elevated intracellular ROS levels. Additionally, DADS induced a marked decrease of ΔΨm and lowered respiration in cell suspensions and isolated mitochondria. In vitro kinetic experiments in cell-free extracts suggest that glutathione-S-transferase (GST) is one of the intracellular targets of DADS. Additional targets were also identified, including inhibition of a site or sites between complexes II-IV in the electron transport chain, as well as the mitochondrial ATP-synthase. The results indicate that DADS is an effective antifungal agent able to trigger cell death in Candida, most probably by eliciting oxidative stress as a consequence of thiol depletion and impaired mitochondrial function. PMID:17534841

  10. Influence of Bacterial Presence on Biofilm Formation of Candida albicans

    PubMed Central

    Park, Su Jung; Han, Kyoung-Hee; Park, Joo Young; Choi, Sun Ju

    2014-01-01

    Purpose Candida albicans is an opportunistic pathogen that is commonly found in human microflora. Biofilm formation (BF) is known as a major virulence factor of C. albicans. The aim of this study was to examine the influence of bacterial presence on biofilm formation of C. albicans. Materials and Methods The BF of Candida was investigated when it was co-cultured with C. albicans (C. albicans 53, a yeast with a low BF ability, and C. albicans 163, a yeast with high BF ability) and bacteria. BF was assessed with XTT reduction assay. A scanning electron microscope was used to determine the structure of the biofilm, and real-time reverse transcriptase polymerase chain reaction was used to amplify and quantify hyphae-associated genes. Results Co-culturing with two different types of bacteria increased the BF value. Co-culturing with C. albicans 53 and 163 also increased the BF value compared to the value that was obtained when the C. albicans was cultured individually. However, co-culturing with bacteria decreased the BF value of C. albicans, and the BF of C. albicans 163 was markedly inhibited. The expression of adherence and morphology transition related genes were significantly inhibited by co-culturing with live bacteria. Conclusion Bacteria have a negative effect on the formation of biofilm by C. albicans. This mechanism is the result of the suppression of genes associated with the hyphae transition of C. albicans, and bacteria particles physically affected the biofilm architecture and biofilm formation. PMID:24532517

  11. Antifungal effect of lavender honey against Candida albicans , Candida krusei and Cryptococcus neoformans.

    PubMed

    Estevinho, Maria Leticia; Afonso, Sílvia Esteves; Feás, Xesús

    2011-10-01

    Monofloral lavender honey samples (n = 30), were analyzed to test antifungal effect against Candida albicans, Candida krusei, and Cryptococcus neoformans. The specific growth rates (μ) showed that all the yeast growths were reduced in the presence of honey. The honey concentration (% w/v) that inhibited 10% of the yeasts growth (X min) ranged from 31.0% (C. albicans), 16.8% (C. krusei) and 23.0% (C. neoformans). A synthetic honey solution was also tested to determine antifungal activity attributable to sugars. The presence of synthetic honey in the C. krusei culture medium at concentrations above 58.0% (w/v) was established as X min, while C. albicans and C. neoformans were more resistant, since X min values were not reached over the ranged tested (10-60%, w/v). What the data suggests is that the component in the lavender honey responsible for the observed antifungal in vitro properties is not sugar based. Honey might be tapped as a natural resource to look for new medicines for the treatment of mycotic infections. This could be very useful, onsidering the increasing resistance of antifungals. It should be noticed that this is the first study concerning the effect of lavender honey on the growth of pathogenic yeasts.

  12. Influence of Candida krusei and Candida glabrata on Candida albicans gene expression in in vitro biofilms.

    PubMed

    Barros, Patrícia Pimentel; Ribeiro, Felipe Camargo; Rossoni, Rodnei Dennis; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso

    2016-04-01

    The present study aimed to evaluate the interactions between the species Candida albicans, Candida krusei and Candida glabrata in monotypic and mixed biofilm models formed in vitro as well as the relative expression of the ALS1, ALS3, HWP1, BCR1, EFG1, TEC1, SAP5, PLB2 and LIP9 genes. Mixed (C. albicans/C. krusei and C. albicans/C. glabrata) and monotypic biofilms were cultured for 0, 12 and 24h. Gene expression was analyzed in the same biofilm model in which the number of CFU/mL was counted. The C. albicans CFU/mL values were lower at the 12 and 24h time points in the mixed biofilms compared with the monotypic biofilms, and decreases of 56.23% and 64.4% in C. albicans were observed when this species was associated with C. glabrata and C. krusei, respectively. In the presence of C. krusei, the expression of the ALS3, HWP1, BCR1, EFG1 and TEC1 genes of C. albicans was completely inhibited, indicating both transcriptome and the phenotypic antagonism between these two species, but genes related to the secretion of enzymes were stimulated. In the presence of C. glabrata, C. albicans showed a similar gene expression profile to that obtained in association with C. krusei, though it was altered to a lesser degree. We conclude that C. krusei and C. glabrata may alter or inhibit the mechanisms involved in the in vitro adherence and formation of C. albicans biofilms, influencing the pathogenicity of this species and suggesting a competitive interaction with C. krusei and C. glabrata in biofilm formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. The antibacterial agent, moxifloxacin inhibits virulence factors of Candida albicans through multitargeting.

    PubMed

    Jadhav, Ashwini; Bansode, Bhagyashree; Phule, Datta; Shelar, Amruta; Patil, Rajendra; Gade, Wasudev; Kharat, Kiran; Karuppayil, Sankunny Mohan

    2017-05-01

    Fluoroquinolines are broad spectrum fourth generation antibiotics. Some of the Fluoroquinolines exhibit antifungal activity. We are reporting the potential mechanism of action of a fluoroquinoline antibiotic, moxifloxacin on the growth, morphogenesis and biofilm formation of the human pathogen Candida albicans. Moxifloxacin was found to be Candidacidal in nature. Moxifloxacin seems to inhibit the yeast to Hyphal morphogenesis by affecting signaling pathways. It arrested the cell cycle of C. albicans at S phase. Docking of moxifloxacin with predicted structure of C. albicans DNA Topoisomerase II suggests that moxifloxacin may bind and inhibit the activity of DNA Topoisomerase II in C. albicans. Moxifloxacin could be used as a dual purpose antibiotic for treating mixed infections caused by bacteria as well as C. albicans. In addition chances of developing moxifloxacin resistance in C. albicans are less considering the fact that moxifloxacin may target multiple steps in yeast to hyphal transition in C. albicans.

  14. Growth phase-dependent variations in transcript profiles for thioredoxin- and glutathione-dependent redox systems followed by budding and hyphal Candida albicans cultures.

    PubMed

    Michán, Carmen; Pueyo, Carmen

    2009-10-01

    We report the absolute transcription profiles of 24 genes coding for putative thioredoxin (Trx)- and glutathione (GSH)-dependent redox system components, accompanying the Candida albicans batch culture growth, under either yeast or hyphal conditions. All mRNAs investigated (plus the housekeeping ACT1) displayed significant alterations in their steady-state copy number. Collectively, these quantifications show that: (1) the most abundant mRNAs during active growth coded for putative thiol peroxidases (TSA1, PRX1, AHP11 and AHP12) and for donor thioredoxin Trx1p, i.e. those five mRNAs represented >74% of all transcript molecules quantified in a late exponential phase; (2) the transcripts under study differed between budding and hyphal cells not only in their abundance but also in their profiles throughout the growth stages; (3) mRNA amounts for four GSH-transferase putative genes (GTT12, GTT13, GTT14 and GST3) increased in the stationary phase in yeast but not under filamentous conditions. Hydrogen peroxide resistance, plus GSH, GSSG and reactive oxygen species contents, throughout yeast and hyphal growth, were also studied, and the differences observed were related to the transcript profiles.

  15. Fluctuations in glycolytic mRNA levels during morphogenesis in Candida albicans reflect underlying changes in growth and are not a response to cellular dimorphism.

    PubMed

    Swoboda, R K; Bertram, G; Delbrück, S; Ernst, J F; Gow, N A; Gooday, G W; Brown, A J

    1994-08-01

    The levels of pyruvate kinase (PYK1), alcohol dehydrogenase (ADH1), phosphoglycerate kinase (PGK1) and phosphoglycerate mutase (GPM1) mRNAs were measured during batch growth and during the yeast-to-hyphal transition in Candida albicans. The four mRNAs behaved in a similar fashion. PYK1, ADH1, PGK1 and GPM1 mRNA levels were shown to increase dramatically during the exponential growth phase of the yeast form, and then to decrease to relatively low levels in the stationary phase. The dimorphic transition was induced using two sets of conditions: (i) an increase in temperature (from 25 degrees C to 37 degrees C) combined with the addition of serum to the medium; and (ii) an increase in temperature (from 25 degrees C to 37 degrees C) and an increase in pH of the growth medium (from pH 4.5 to pH 6.5). Additional cultures were analysed to control for the addition of serum, and for changes in temperature or pH. Immediately following dilution of late-exponential cells into fresh media the levels of all four glycolytic mRNAs decreased rapidly in contrast to the ACT1 mRNA control, the level of which increased under most conditions. The recovery of glycolytic mRNA levels depended on the culture conditions, but there was no direct correlation with the formation of germ tubes, with the addition of serum to the medium, the increase in culture temperature, the medium pH, or the glucose concentration. This indicates that the changes in glycolytic gene expression that accompany the dimorphic transition in C. albicans reflect the underlying physiological status of the cells during morphogenesis and not alterations to cell shape.

  16. Lemongrass-Incorporated Tissue Conditioner Against Candida albicans Culture

    PubMed Central

    Amornvit, Pokpong; Srithavaj, Theerathavaj

    2014-01-01

    Background: Tissue conditioner is applied popularly with dental prosthesis during wound healing process but it becomes a reservoir of oral microbiota, especially Candida species after long-term usage. Several antifungal drugs have been mixed with this material to control fungal level. In this study, lemongrass essential oil was added into COE-COMFORT tissue conditioner before being determined for anti-Candida efficacy. Materials and Methods: Lemongrass (Cymbopogon citratus) essential oil was primarily determined for antifungal activity against C. albicans American type culture collection (ATCC) 10231 and MIC (minimum inhibitory concentration) value by agar disk diffusion and broth microdilution methods, respectively. COE-COMFORT tissue conditioner was prepared as recommended by the manufacturer after a fixed volume of the oil at its MIC or higher concentrations were mixed thoroughly in its liquid part. Antifungal efficacy of the tissue conditioner with/without herb was finally analyzed. Results: Lemongrass essential oil displayed potent antifungal activity against C. albicans ATCC 10231and its MIC value was 0.06% (v/v). Dissimilarly, the tissue conditioner containing the oil at MIC level did not cease the growth of the tested fungus. Both reference and clinical isolates of C. albicans were completely inhibited after exposed to the tissue conditioner containing at least 0.25% (v/v) of the oil (approximately 4-time MIC). The tissue conditioner without herb or with nystatin was employed as negative or positive control, respectively. Conclusion: COE-COMFORT tissue conditioner supplemented with lemongrass essential oil obviously demonstrated another desirable property as in vitro anti-Candida efficacy to minimize the risk of getting Candidal infection. PMID:25177638

  17. Killer system: a simple method for differentiating Candida albicans strains.

    PubMed Central

    Polonelli, L; Archibusacci, C; Sestito, M; Morace, G

    1983-01-01

    The killer effect of 37 species of Candida, Cryptococcus, Hansenula, Pichia, Rhodotorula, Saccharomyces, and Trichosporon on 100 Candida albicans isolates of human and animal origin was studied. All of the C. albicans cultures were sensitive to one or more killer yeasts. The factors affecting the killer phenomenon on C. albicans were investigated for realizing a simple system for the differentiation of the 100 C. albicans isolates. By using this system, it was possible to differentiate up to 512 isolates of C. albicans according to their susceptibility to the killer effect of nine selected killer yeasts. The use of this method as an epidemiological marker in the case of presumptive nosocomial infections due to C. albicans is also reported. Images PMID:6345575

  18. Postantifungal effect of caspofungin against the Candida albicans and Candida parapsilosis clades.

    PubMed

    Gil-Alonso, Sandra; Jauregizar, Nerea; Eraso, Elena; Quindós, Guillermo

    2016-10-01

    Killing and postantifungal effects could be relevant for the selection of optimal dosing schedules. This study aims to compare time-kill and postantifungal effects with caspofungin on Candida albicans (C. albicans, Candida dubliniensis, Candida africana) and Candida parapsilosis (C. parapsilosis, Candida metapsilosis, Candida orthopsilosis) clades. In the postantifungal effect experiments, strains were exposed to caspofungin for 1 h at concentrations 0.12-8 μg/mL. Time-kill experiments were conducted at the same concentrations. Caspofungin exhibited a significant and prolonged postantifungal effect (>37 h) with 2 μg/mL against the most strains of C. albicans clade. Against the C. parapsilosis clade, the postantifungal effect was <12 h at 8 μg/mL, except for two strains. Caspofungin was fungicidal against C. albicans, C. dubliniensis and C. metapsilosis. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. In Vitro Antifungal Activity of Equol against Candida albicans

    PubMed Central

    Lee, Jeong Ah

    2010-01-01

    In this study, we demonstrate that equol has fungicidal activities against Candida albicans. The minimum inhibitory and minimum fungicidal concentrations of equol against C. albicans were 516 and 1,032 µM, respectively. Two separate viability assays found that equol changed the integrity of the C. albicans cell membrane, possibly by formation of membrane lesions. Scanning electron microscopy demonstrated ultrastructural changes. PMID:23956675

  20. [Utility of Fluoroplate Candida for the rapid identification of Candida albicans].

    PubMed

    Quindós, G; San Millan, R; Bikandi, J; Pontón, J

    1996-12-01

    Candida albicans infections are frequent in immunocompromised patients and a prompt diagnosis could favor an early and proper antifungal treatment. The rapid identification of clinical yeast isolates facilitate this diagnosis. The utility of Fluoroplate Candida ready-to-use plates for Candida albicans rapid identification was evaluated with 653 clinical isolates from 23 yeast species, including 307 C. albicans plated onto Fluoroplate Candida agar (Merck, Germany). Rapid identification of C. albicans was based on the hydrolysis of 4-methylumbelliferyl-N-acetyl-beta-D-galactosaminide by the galactosaminidase activity of C. albicans producing white fluorescent colonies under ultraviolet light. Identification on Fluoroplate Candida was confirmed by germ tube, chlamydoconidia formation and API-ATB ID 32C assays. Three hundred and five of 306 isolates showing fluorescent colonies were C. albicans and one was Candida glabrata (false positive). The rest of the isolates showed colonies without fluorescence and with the exception of two false negatives, these isolates were identified as non-C. albicans by other methods. Fluoroplate Candida allows a rapid and excellent identification of C. albicans showing a sensitivity and specificity of 99.3 and 99.7%, respectively.

  1. Detection of Antibodies to Candida albicans Germ Tubes during Experimental Infections by Different Candida Species

    PubMed Central

    Bikandi, Joseba; San Millán, Rosario; Regúlez, Pilar; Moragues, María D.; Quindós, Guillermo; Pontón, José

    1998-01-01

    Identification and characterization of Candida albicans germ tube-specific antigens may be of relevance for the serodiagnosis of invasive candidiasis since they could be the basis for the development of new diagnostic tests. In this study, we have identified two antigens of 180 and >200 kDa in the cell wall of C. albicans germ tubes which are responsible for the induction of antibodies to C. albicans germ tubes. Antigens of similar molecular masses have been demonstrated in the cell walls of the Candida species C. stellatoidea, C. parapsilosis, C. guilliermondii, C. tropicalis, and C. krusei, but not C. glabrata. The kinetics of the antibody responses to C. albicans germ tubes were studied in rabbits infected with different Candida species. Although these antibodies were detected in rabbits infected with all Candida species except C. glabrata, the kinetics of the antibody responses to C. albicans germ tubes induced by the Candida species studied were different. Both the highest titer and the earliest response of antibodies to C. albicans germ tubes were observed in rabbits infected with either of the two serotypes of C. albicans used. However, the time needed to elicit the antibodies to C. albicans germ tubes can be reduced as the result of an anamnestic antibody response. The results presented in this study show that a test designed to detect antibodies against C. albicans germ tube antigens may be suitable for the diagnosis of infections caused by most of the medically important Candida species. PMID:9605993

  2. Unusually large telomeric repeats in the yeast Candida albicans.

    PubMed Central

    McEachern, M J; Hicks, J B

    1993-01-01

    We have identified sequences at the telomeres of the yeast Candida albicans and have found that they are composed of tandem copies of a 23-bp sequence. Through the cloning of native telomeric ends and the characterization and cloning of a "healed" end, we demonstrate that these repeated sequences are sufficient to function as a telomere. All copies of the 23-bp repeat that have been sequenced from a number of C. albicans strains are identical. In contrast, adjacent subtelomeric sequences are variable both between strains and within the WO-1 strain. In the WO-1 strain, the lengths of the telomeres are dependent upon growth temperature and are substantially longer at higher temperatures. Telomere growth is accompanied by increases in the number of the 23-bp repeats present on the telomeric fragments. These results suggest that either telomerase-maintained telomeres can be more complex in structure than was previously imagined or that Candida telomeres are maintained via a telomerase-independent mechanism. Images PMID:8417351

  3. [Candida: epidemiology and risk factors for non-albicans species].

    PubMed

    Cornistein, Wanda; Mora, Andrea; Orellana, Nora; Capparelli, Federico Javier; del Castillo, Marcelo

    2013-01-01

    Nosocomial fungal infections have increased significantly in the last decade. Candida detection in clinical specimens can mean either colonization or an infection which can be local (muguet) or invasive. Knowledge of the species helps in choosing the best treatment. The aims of this study were to determine the frequency and distribution of Candida species detected in clinical samples, to analyze the clinical characteristics of the involved population and to determine the risk factors for Candida non-albicans species. Retrospective, observational. 2006-2010. all isolates of Candida in clinical specimens from patients hospitalized at least 48 hours in a neurological center. We analyzed epidemiological characteristics, co morbidities, risk factors, factors associated with Candida non-albicans detection, antifungal treatment, development of adverse events and mortality. Candida spp. was isolated from 321 clinical specimens: 139 (43.3%) were C. albicans and 182 (56.7%) Candida non-albicans. The distribution of the sample was: urine 122 (Candida non-albicans 67.2%), airway 81, oropharynx 45 (C. albicans) and candidemia 40 (Candida non-albicans 75%). The most frequent co-morbidity was solid tumor (35.5%). The main risk factors were antibiotic therapy (85.5%), steroid therapy (61.7%) and in ICU at diagnosis (61.6%). The analysis of risk factors and the isolation of Candida non-albicans shows that chemotherapy, previous surgery, treatment with aminopenicillins, carbapenems and glycopeptides were statistically significant (P<.05). There is a trend in neutropenic patients (P=.055) and in ICU at diagnosis (P=.076). Overall survival was 71%. Candida species distribution varies with the type of sample analyzed. Non-albicans species make up the majority of the isolates. The identification of the species involved per sample helps to optimize treatment. The high frequency of isolation of Candida in patients on steroids and antibiotics and admitted to ICU, is worth pointing out

  4. Effect of Low-Level Laser therapy on the fungal proliferation of Candida albicans

    NASA Astrophysics Data System (ADS)

    Carneiro, Vanda S. M.; Araújo, Natália C.; Menezes, Rebeca F. d.; Moreno, Lara M.; Santos-Neto, Alexandrino d. P.; Gerbi, Marleny Elizabeth M.

    2016-03-01

    Candida albicans plays an important role in triggering infections in HIV+ patients. The indiscriminate use of antifungals has led to resistance to Candida albicans, which requires new treatment alternatives for oral candidiasis. Low-level laser therapy promotes a considerable improvement in the healing of wounds and in curing illnesses caused by microorganisms. The aim of the present study was to assess the effect of laser radiation on the cell proliferation of Candida albicans in immunosuppressed patients. Six Candida albicans strains that had been isolated from immunosuppressed patients were divided into a control group and experimental groups, which received eight sessions of laser therapy (InGaAlP, λ685nm, P = 30mW, CW, Φ~6 mm and GaAlAs, λ830nm, P = 40mW, CW, Φ~6 mm) using dosimetries of 6J/cm2, 8J/cm2, 10J/cm2 and 12J/cm2 for each wavelength and power. The results were not statistically significant (Kruskal Wallis, p > 0.05), although the proliferation of Candida albicans was lower in some of the experimental groups. The dosimetry of 6J/cm2 (GaAlAs, λ830nm, P = 40mW) provided lower mean scores than the other groups for the growth of Candida. Further studies are required to confirm whetehr laser therapy is a viable option in the treatment of fungal infections.

  5. Sur7 Promotes Plasma Membrane Organization and Is Needed for Resistance to Stressful Conditions and to the Invasive Growth and Virulence of Candida albicans

    PubMed Central

    Douglas, Lois M.; Wang, Hong X.; Keppler-Ross, Sabine; Dean, Neta; Konopka, James B.

    2011-01-01

    ABSTRACT The human fungal pathogen Candida albicans causes lethal systemic infections because of its ability to grow and disseminate in a host. The C. albicans plasma membrane is essential for virulence by acting as a protective barrier and through its key roles in interfacing with the environment, secretion of virulence factors, morphogenesis, and cell wall synthesis. Difficulties in studying hydrophobic membranes have limited the understanding of how plasma membrane organization contributes to its function and to the actions of antifungal drugs. Therefore, the role of the recently discovered plasma membrane subdomains termed the membrane compartment containing Can1 (MCC) was analyzed by assessing the virulence of a sur7Δ mutant. Sur7 is an integral membrane protein component of the MCC that is needed for proper localization of actin, morphogenesis, cell wall synthesis, and responding to cell wall stress. MCC domains are stable 300-nm-sized punctate patches that associate with a complex of cytoplasmic proteins known as an eisosome. Analysis of virulence-related properties of a sur7Δ mutant revealed defects in intraphagosomal growth in macrophages that correlate with increased sensitivity to oxidation and copper. The sur7Δ mutant was also strongly defective in pathogenesis in a mouse model of systemic candidiasis. The mutant cells showed a decreased ability to initiate an infection and greatly diminished invasive growth into kidney tissues. These studies on Sur7 demonstrate that the plasma membrane MCC domains are critical for virulence and represent an important new target for the development of novel therapeutic strategies. PMID:22202230

  6. Derivation of an in vivo drug exposure breakpoint for flucytosine against Candida albicans and Impact of the MIC, growth rate, and resistance genotype on the antifungal effect.

    PubMed

    Hope, William W; Warn, Peter A; Sharp, Andrew; Howard, Susan; Kasai, Miki; Louie, Arnold; Walsh, Thomas J; Drusano, George L; Denning, David W

    2006-11-01

    Drug exposure or pharmacodynamic breakpoints refer to a magnitude of drug exposure which separates a population into groups with high and low probabilities of attaining a desired outcome. We used a pharmacodynamic model of disseminated candidiasis to define an in vivo drug exposure breakpoint for flucytosine (5FC) against Candida albicans. The results were bridged to humans by using population pharmacokinetics and Monte Carlo simulation. An in vivo drug exposure breakpoint for 5FC was apparent when serum levels were above the MIC for 45% of the dosing interval. The Monte Carlo simulations suggested that using a human dose of 100 mg/kg of body weight/day in four divided doses, 5FC resistance was defined at an MIC of 32 mg/liter. Target attainment rates following administration of 25, 50, and 100 mg/kg/day were similar, suggesting that the use of a lower dose of 5FC is possible. Using six isolates of C. albicans with MICs ranging from 0.06 to >64 mg/liter, we also explored the influence that the MIC, the fraction of the dosing interval that the serum levels of 5FC remained above the MIC (T>MIC), the 5FC resistance genotype, and the in vivo growth rate had on the response to 5FC. The MIC and T>MIC were both critical measures affecting the generation of a drug effect but had no bearing on the magnitude of the maximal kill induced by 5FC. The in vivo growth rate was a critical additional determinant of the exposure-response relationship. There was a relationship between the 5FC resistance genotype and the exposure-response relationship.

  7. Antifungal activity of Piper aduncum and Peperomia pellucida leaf ethanol extract against Candida albicans

    NASA Astrophysics Data System (ADS)

    Hastuti, Utami Sri; Ummah, Yunita Putri Irsadul; Khasanah, Henny Nurul

    2017-05-01

    This research was done to 1) examine the effect of Piper aduncum leaf ethanol extract at certain concentrations against Candida albicans colony growth inhibition in vitro; 2) examine the effect of Peperomia pellucida leaf ethanol extract at certain concentrations toward Candida albicans colony growth inhibition in vitro; and 3) determine the most effective concentration of P. aduncum and P. pellucida leaves ethanol extract against C. albicans colony growth inhibition in vitro. These plant extracts were prepared by the maceration technique using 95% ethanol, and then sterile filtered and evaporated to obtain the filtrate. The filtrate was diluted with sterile distilled water at certain concentrations, i.e.: 0%, 10%, 20%, 30%, 405, 50%, 60%, 70%, 80%, and 90%. The antifungal effect of each leaf extract concentration was examined by the agar diffusion method on Sabouraud Dextrose Agar medium. The research results are: 1) the P.aduncum leaf ethanol extract at some concentrations has an effect against C. albicans colony growth inhibition in vitro; 2) the P.pellucida leaf ethanol extract at some concentrations has an effect against C. albicans colony growth inhibition in vitro; 3) the P. aduncum leaf ethanol extract at 80% is the most effective for C. albicans colony growth inhibition in vitro; and 4) the P. pellucida leaf ethanol extract at 70% is the most effective for C. albicans colony growth inhibition in vitro.

  8. Dose-dependent effect of lysozyme upon Candida albicans biofilm

    PubMed Central

    Sebaa, Sarra; Hizette, Nicolas; Boucherit-Otmani, Zahia; Courtois, Philippe

    2017-01-01

    The present study investigated the in vitro effect of lysozyme (0–1,000 µg/ml) on Candida albicans (C. albicans) biofilm development. Investigations were conducted on C. albicans ATCC 10231 and on 10 clinical isolates from dentures. Strains were cultured aerobically at 37°C in Sabouraud broth. Yeast growth was evaluated by turbidimetry. Biofilm biomass was quantified on a polystyrene support by crystal violet staining and on acrylic surfaces by counts of colony forming units. Lysozyme affected biofilm formation to a greater extent than it affected growth. For the ATCC 10231 reference strain, lysozyme acted as a biofilm promotor on polystyrene at the highest concentration tested (1,000 µg/ml, non-physiological). When the reference strain was investigated on acrylic resin support, lysozyme acted as a significant biofilm promotor on rough resin, but less on smooth resin. The attached biomass in the presence of physiological concentrations of lysozyme (10–30 µg/ml) was significantly decreased compared with the hypothetical value of 100% using a one-sample t-test, but a comparison between the different lysozyme conditions using analysis of variance and post hoc tests did not reveal significant differences. In 10 wild strains, different patterns of biofilm formation on polystyrene were observed in the presence of lysozyme. Some strains, characterized by large amounts of biofilm formation in the presence of 1,000 µg/ml lysozyme, were poor biofilm producers at low concentrations of lysozyme. In contrast, some strains that were poor biofilm producers with a high lysozyme concentration were more inhibited by low concentrations of lysozyme. The present study emphasizes the need to develop strategies for biofilm control based on in vitro experiments, and to implement these in clinical trials prior to approval of hygiene products enriched with exocrine proteins, such as lysozyme. Further studies will extend these investigations to other Candida species, and to fungi

  9. Antimicrobial effects of liquid anesthetic isoflurane on Candida albicans

    PubMed Central

    Barodka, Viachaslau M; Acheampong, Edward; Powell, Garry; Lobach, Ludmila; Logan, David A; Parveen, Zahida; Armstead, Valerie; Mukhtar, Muhammad

    2006-01-01

    Candida albicans is a dimorphic fungus that can grow in yeast morphology or hyphal form depending on the surrounding environment. This ubiquitous fungus is present in skin and mucus membranes as a potential pathogen that under opportunistic conditions causes a series of systemic and superficial infections known as candidiasis, moniliasis or simply candidiasis. There has been a steady increase in the prevalence of candidiasis that is expressed in more virulent forms of infection. Although candidiasis is commonly manifested as mucocutaneous disease, life-threatening systemic invasion by this fungus can occur in every part of the body. The severity of candidal infections is associated with its morphological shift such that the hyphal morphology of the fungus is most invasive. Of importance, aberrant multiplication of Candida yeast is also associated with the pathogenesis of certain mucosal diseases. In this study, we assessed the anti-candidal activity of the volatile anesthetic isoflurane in liquid form in comparison with the anti-fungal agent amphotericin B in an in vitro culture system. Exposure of C. albicans to isoflurane (0.3% volume/volume and above) inhibited multiplication of yeast as well as formation of hyphae. These data suggest development of potential topical application of isoflurane for controlling a series of cutaneous and genital infections associated with this fungus. Elucidiation of the mechanism by which isoflurane effects fungal growth could offer therapeutic potential for certain systemic fungal infections. PMID:17094810

  10. Candida albicans Ultrastructure: Colonization and Invasion of Oral Epithelium

    PubMed Central

    Howlett, Julie A.; Squier, Christopher A.

    1980-01-01

    The colonization and invasion of various animal oral mucosae by Candida albicans were examined in an organ culture model. Scanning and transmission electron microscopy of the oral epithelium between 12 and 30 h after inoculation with the fungus revealed the morphological relationships between host and parasite. Examination of the fungi in thin sections showed five distinct layers in the cell wall of C. albicans within the epithelium, but changes were evident in the organization and definition of the outer cell wall layers in budding hyphae and in hyphae participating in colonization and invasion of the epithelial cells. Adherence of the fungus to the superficial cells of the oral mucosa appeared to involve intimate contact between the epithelial cell surface and the deeper layers of the fungal cell wall. During invasion a close seal was maintained between the invading hyphae and the surrounding epithelial cell envelope, there being no other evidence of damage to the host cell surface except at the site of entry. Within the epithelial cells there was only occasional loss of cytoplasmic components in the vicinity of the invading hyphae. These findings would suggest that enzymatic lysis associated with the invasive process is localized and that the mechanical support provided by surface adherence and the intimate association between the fungus and the epithelial cell envelope may permit growth of Candida on through the epithelium. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 PMID:6995338

  11. Chloroquine sensitizes biofilms of Candida albicans to antifungal azoles.

    PubMed

    Shinde, Ravikumar Bapurao; Raut, Jayant Shankar; Chauhan, Nitin Mahendra; Karuppayil, Sankunny Mohan

    2013-01-01

    Biofilms formed by Candida albicans, a human pathogen, are known to be resistant to different antifungal agents. Novel strategies to combat the biofilm associated Candida infections like multiple drug therapy are being explored. In this study, potential of chloroquine to be a partner drug in combination with four antifungal agents, namely fluconazole, voriconazole, amphotericin B, and caspofungin, was explored against biofilms of C. albicans. Activity of various concentrations of chloroquine in combination with a particular antifungal drug was analyzed in a checkerboard format. Growth of biofilm in presence of drugs was analyzed by XTT-assay, in terms of relative metabolic activity compared to that of drug free control. Results obtained by XTT-metabolic assay were confirmed by scanning electron microscopy. The interactions between chloroquine and four antifungal drugs were determined by calculating fractional inhibitory concentration indices. Azole resistance in biofilms was reverted significantly (p<0.05) in presence of 250μg/mL of chloroquine, which resulted in inhibition of biofilms at very low concentrations of antifungal drugs. No significant alteration in the sensitivity of biofilms to caspofungin and amphotericin B was evident in combination with chloroquine. This study for the first time indicates that chloroquine potentiates anti-biofilm activity of fluconazole and voriconazole.

  12. Rax2 is important for directional establishment of growth sites, but not for reorientation of growth axes, during Candida albicans hyphal morphogenesis

    PubMed Central

    Gonia, Sara; Norton, Jennifer; Watanaskul, Lindy; Pulver, Rebecca; Morrison, Emma; Brand, Alexandra; Gale, Cheryl A.

    2013-01-01

    Hyphae of filamentous fungi maintain generally linear growth over long distances. In C. albicans, hyphae are able to reorient their growth in the direction of certain environmental cues. In previous work, the C. albicans bud-site selection proteins Rsr1 and Bud2 were identified as important for hyphae to maintain linear growth and were necessary for hyphal responses to directional cues in the environment (tropisms). To ask if hyphal directional responses are general functions of all yeast bud-site selection proteins, we studied the role of Rax2, ortholog of the S. cerevisiae bud-site selection protein Rax2, in C. albicans hyphal morphogenesis. Rax2-YFP localized to the hyphal cell surface in puncta and at the hyphal tip in a crescent. Strains lacking Rax2 had hyphal morphologies that did not differ from control strains. In non-cued growth conditions, rax2 mutant strains had defects in both yeast (bud) and hyphal (branch) site selection and mutant hyphae exhibited non-linear growth trajectories as compared to control hyphae. In contrast, when encountering a directional environmental cue, hyphae lacking Rax2 retained the ability to reorient growth in response to both topographical (thigmotropism) and electric-field (galvanotropism) stimuli but exhibited a reduced ability to establish hyphal growth in the direction of a cathodal stimulus. In conclusion, these results indicate that C. albicans Rax2 is important for establishing sites of emergence of yeast and hyphal daughters and for maintaining the linearity of hyphal growth. In contrast to Rsr1 and Bud2, Rax2 is not involved in responses that require a reorientation of the direction of already established hyphal growth (tropisms). Thus, it appears that some hyphal directionality responses are separable in that they are mediated by a different set of polarity proteins. PMID:23608319

  13. Human serum inhibits adhesion and biofilm formation in Candida albicans

    PubMed Central

    2014-01-01

    Background Candida albicans can form biofilms on intravenous catheters; this process plays a key role in the pathogenesis of catheter infections. This study evaluated the effect of human serum (HS) on C. albicans biofilm formation and the expression of adhesion-related genes in vitro. A C. albicans laboratory strain (ATCC90028) and three clinical strains were grown for 24 h in RPMI 1640 supplemented with HS or RPMI 1640 alone (as a control). The growth of biofilm cells of four strains was monitored by a Live Cell Movie Analyzer, and by XTT reduction assay. The expression of the adhesion-related genes BCR1, ALS1, ALS3, HWP1 and ECE1 was analyzed by RT-PCR at three time points (60 min, 90 min, and 24 h). Results In the adhesion phase, C. albicans cells kept a Brownian movement in RPMI medium containing HS until a large number of germ tubes were formed. In the control group, C. albicans cells quickly adhered to the bottom of the reaction plate. Compared with RPMI 1640, medium supplemented with 3–50% HS caused a significant decrease in biofilm development (all p < 0.001). However, the presence of HS had no significant inhibitory effect on the pre-adhered biofilms (all p > 0.05). Biofilm formation was also inhibited by heat-inactivated and proteinase K pre-treated HS. The presence of 50% HS did not significantly affect the planktonic growth of C. albicans (p > 0.05). At three time points, HS inhibited expression of the ALS1 and ALS3 genes and promoted expression of the HWP1 and ECE1 genes. Significant up-regulation of BCR1 was observed only at the 90-min point. Conclusions Human serum reduces biofilm formation by inhibiting the adhesion of C. albicans cells. This response may be associated with the down-regulation of adhesion-related genes ALS1, ALS3 and BCR1. The inhibitory serum component is protease-resistant and heat stable. PMID:24673895

  14. Oxidant-specific regulation of protein synthesis in Candida albicans.

    PubMed

    Sundaram, Arunkumar; Grant, Chris M

    2014-06-01

    Eukaryotic cells typically respond to stress conditions by inhibiting global protein synthesis. The initiation phase is the main target of regulation and represents a key control point for eukaryotic gene expression. In Saccharomyces cerevisiae and mammalian cells this is achieved by phosphorylation of eukaryotic initiation factor 2 (eIF2α). We have examined how the fungal pathogen Candida albicans responds to oxidative stress conditions and show that oxidants including hydrogen peroxide, the heavy metal cadmium and the thiol oxidant diamide inhibit translation initiation. The inhibition in response to hydrogen peroxide and cadmium largely depends on phosphorylation of eIF2α since minimal inhibition is observed in a gcn2 mutant. In contrast, translation initiation is inhibited in a Gcn2-independent manner in response to diamide. Our data indicate that all three oxidants inhibit growth of C. albicans in a dose-dependent manner, however, loss of GCN2 does not improve growth in the presence of hydrogen peroxide or cadmium. Examination of translational activity indicates that these oxidants inhibit translation at a post-initiation phase which may account for the growth inhibition in a gcn2 mutant. As well as inhibiting global translation initiation, phosphorylation of eIF2α also enhances expression of the GCN4 mRNA in yeast via a well-known translational control mechanism. We show that C. albicans GCN4 is similarly induced in response to oxidative stress conditions and Gcn4 is specifically required for hydrogen peroxide tolerance. Thus, the response of C. albicans to oxidative stress is mediated by oxidant-specific regulation of translation initiation and we discuss our findings in comparison to other eukaryotes including the yeast S. cerevisiae. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Molecular epidemiology, phylogeny and evolution of Candida albicans.

    PubMed

    McManus, Brenda A; Coleman, David C

    2014-01-01

    A small number of Candida species form part of the normal microbial flora of mucosal surfaces in humans and may give rise to opportunistic infections when host defences are impaired. Candida albicans is by far the most prevalent commensal and pathogenic Candida species. Several different molecular typing approaches including multilocus sequence typing, multilocus microsatellite typing and DNA fingerprinting using C. albicans-specific repetitive sequence-containing DNA probes have yielded a wealth of information regarding the epidemiology and population structure of this species. Such studies revealed that the C. albicans population structure consists of multiple major and minor clades, some of which exhibit geographical or phenotypic enrichment and that C. albicans reproduction is predominantly clonal. Despite this, losses of heterozygosity by recombination, the existence of a parasexual cycle, toleration of a wide range of aneuploidies and the recent description of viable haploid strains have all demonstrated the extensive plasticity of the C. albicans genome. Recombination and gross chromosomal rearrangements are more common under stressful environmental conditions, and have played a significant role in the evolution of this opportunistic pathogen. Surprisingly, Candida dubliniensis, the closest relative of C. albicans exhibits more karyotype variability than C. albicans, but is significantly less adaptable to unfavourable environments. This disparity most likely reflects the evolutionary processes that occurred during or soon after the divergence of both species from their common ancestor. Whilst C. dubliniensis underwent significant gene loss and pseudogenisation, C. albicans expanded gene families considered to be important in virulence. It is likely that technological developments in whole genome sequencing and data analysis in coming years will facilitate its routine use for population structure, epidemiological investigations, and phylogenetic analyses of

  16. Chlorhexidine markedly potentiates the oxidants scavenging abilities of Candida albicans.

    PubMed

    Ginsburg, I; Koren, E; Feuerstein, O; Zogakis, I P; Shalish, M; Gorelik, S

    2015-10-01

    The oxidant scavenging ability (OSA) of catalase-rich Candida albicans is markedly enhanced by chlorhexidine digluconate (CHX), polymyxin B, the bile salt ursodeoxycholate and by lysophosphatidylcholine, which all act as detergents facilitating the penetration of oxidants and their intracellular decomposition. Quantifications of the OSA of Candida albicans were measured by a highly sensitive luminol-dependent chemiluminescence assay and by the Thurman's assay, to quantify hydrogen peroxide (H2O2). The OSA enhancing activity by CHX depends to some extent on the media on which candida grew. The OSA of candida treated by CHX was modulated by whole human saliva, red blood cells, lysozyme, cationic peptides and by polyphenols. Concentrations of CHX, which killed over 95 % of Candida albicans cells, did not affect the cells' abilities to scavenge reactive oxygen species (ROS). The OSA of Candida cells treated by CHX is highly refractory to H2O2 (50 mM) but is strongly inhibited by hypochlorous acid, lecithin, trypan blue and by heparin. We speculate that similarly to catalase-rich red blood cells, Candida albicans and additional catalase-rich microbiota may also have the ability to scavenge oxidants and thus can protect catalase-negative anaerobes and facultative anaerobes cariogenic streptococci against peroxide and thus secure their survival in the oral cavity.

  17. High-frequency switching in Candida albicans.

    PubMed Central

    Soll, D R

    1992-01-01

    Most strains of Candida albicans are capable of switching frequently and reversibly between a number of phenotypes distinguishable by colony morphology. A number of different switching systems have been defined according to the limited set of phenotypes in each switching repertoire, and each strain appears to possess a single system. Switching can affect many aspects of cellular physiology and morphology and appears to be a second level of phenotypic variability superimposed upon the bud-hypha transition. The most dramatic switching system so far identified is the "white-opaque transition." This system dramatizes the extraordinary effects switching can have on the budding cell phenotype, including the synthesis of opaque-specific antigens, the expression of white-specific and opaque-specific genes, and the genesis of unique cell wall structures. Switching has been demonstrated to occur at sites of infection and between episodes of recurrent vaginitis, and it may function to generate variability in commensal and infecting populations for adaptive reasons. Although the molecular mechanisms involved in the switch event are not understood, recent approaches to its elucidation are discussed and an epigenetic mechanism is proposed. Images PMID:1576587

  18. Environmental induction of white-opaque switching in Candida albicans.

    PubMed

    Ramírez-Zavala, Bernardo; Reuss, Oliver; Park, Yang-Nim; Ohlsen, Knut; Morschhäuser, Joachim

    2008-06-13

    Candida albicans strains that are homozygous at the mating type locus (MTLa or MTLalpha) can spontaneously switch at a low frequency from the normal yeast cell morphology (white) to an elongated cell type (opaque), which is the mating-competent form of the fungus. The ability to switch reversibly between these two cell types also contributes to the pathogenicity of C. albicans, as white and opaque cells are differently adapted to specific host niches. We found that in strain WO-1, a strain in which genomic alterations have occurred, but not in other tested strains, switching from the white to the opaque phase can also be induced by environmental conditions. Transient incubation of white cells under anaerobic conditions programmed the cells to switch en masse to the opaque phase. The anaerobic induction of white-opaque switching was controlled by the transcription factor CZF1, which in heterozygous MTLa/alpha cells regulates filamentous growth under embedded, hypoxic conditions. Intriguingly, passage of white cells of strain WO-1 through the mouse intestine, a host niche in which the cells are likely to be exposed to anaerobic conditions, resulted in a strongly increased frequency of switching to the opaque phase. These results demonstrate that white-opaque switching is not only a spontaneous process but, in combination with genomic alterations, can also be induced by environmental signals, suggesting that switching and mating of C. albicans may occur with high efficiency in appropriate niches within its human host.

  19. Genetic and phenotypic intra-species variation in Candida albicans

    PubMed Central

    Hirakawa, Matthew P.; Martinez, Diego A.; Sakthikumar, Sharadha; Anderson, Matthew Z.; Berlin, Aaron; Gujja, Sharvari; Zeng, Qiandong; Zisson, Ethan; Wang, Joshua M.; Greenberg, Joshua M.; Berman, Judith

    2015-01-01

    Candida albicans is a commensal fungus of the human gastrointestinal tract and a prevalent opportunistic pathogen. To examine diversity within this species, extensive genomic and phenotypic analyses were performed on 21 clinical C. albicans isolates. Genomic variation was evident in the form of polymorphisms, copy number variations, chromosomal inversions, subtelomeric hypervariation, loss of heterozygosity (LOH), and whole or partial chromosome aneuploidies. All 21 strains were diploid, although karyotypic changes were present in eight of the 21 isolates, with multiple strains being trisomic for Chromosome 4 or Chromosome 7. Aneuploid strains exhibited a general fitness defect relative to euploid strains when grown under replete conditions. All strains were also heterozygous, yet multiple, distinct LOH tracts were present in each isolate. Higher overall levels of genome heterozygosity correlated with faster growth rates, consistent with increased overall fitness. Genes with the highest rates of amino acid substitutions included many cell wall proteins, implicating fast evolving changes in cell adhesion and host interactions. One clinical isolate, P94015, presented several striking properties including a novel cellular phenotype, an inability to filament, drug resistance, and decreased virulence. Several of these properties were shown to be due to a homozygous nonsense mutation in the EFG1 gene. Furthermore, loss of EFG1 function resulted in increased fitness of P94015 in a commensal model of infection. Our analysis therefore reveals intra-species genetic and phenotypic differences in C. albicans and delineates a natural mutation that alters the balance between commensalism and pathogenicity. PMID:25504520

  20. Genetic and phenotypic intra-species variation in Candida albicans.

    PubMed

    Hirakawa, Matthew P; Martinez, Diego A; Sakthikumar, Sharadha; Anderson, Matthew Z; Berlin, Aaron; Gujja, Sharvari; Zeng, Qiandong; Zisson, Ethan; Wang, Joshua M; Greenberg, Joshua M; Berman, Judith; Bennett, Richard J; Cuomo, Christina A

    2015-03-01

    Candida albicans is a commensal fungus of the human gastrointestinal tract and a prevalent opportunistic pathogen. To examine diversity within this species, extensive genomic and phenotypic analyses were performed on 21 clinical C. albicans isolates. Genomic variation was evident in the form of polymorphisms, copy number variations, chromosomal inversions, subtelomeric hypervariation, loss of heterozygosity (LOH), and whole or partial chromosome aneuploidies. All 21 strains were diploid, although karyotypic changes were present in eight of the 21 isolates, with multiple strains being trisomic for Chromosome 4 or Chromosome 7. Aneuploid strains exhibited a general fitness defect relative to euploid strains when grown under replete conditions. All strains were also heterozygous, yet multiple, distinct LOH tracts were present in each isolate. Higher overall levels of genome heterozygosity correlated with faster growth rates, consistent with increased overall fitness. Genes with the highest rates of amino acid substitutions included many cell wall proteins, implicating fast evolving changes in cell adhesion and host interactions. One clinical isolate, P94015, presented several striking properties including a novel cellular phenotype, an inability to filament, drug resistance, and decreased virulence. Several of these properties were shown to be due to a homozygous nonsense mutation in the EFG1 gene. Furthermore, loss of EFG1 function resulted in increased fitness of P94015 in a commensal model of infection. Our analysis therefore reveals intra-species genetic and phenotypic differences in C. albicans and delineates a natural mutation that alters the balance between commensalism and pathogenicity.

  1. Effects of extracellular DNA from Candida albicans and pneumonia-related pathogens on Candida biofilm formation and hyphal transformation.

    PubMed

    Sapaar, B; Nur, A; Hirota, K; Yumoto, H; Murakami, K; Amoh, T; Matsuo, T; Ichikawa, T; Miyake, Y

    2014-06-01

    The aim of this study was to investigate the effects of genomic DNA purified from Candida albicans and pneumonia-related pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, on in vitro biofilm formation and morphological change of 3 Candida species (C. albicans, C. glabrata, and C. tropicalis). Biofilm formation was evaluated by the crystal violet assay and colony-forming unit counts. Morphological characteristics of biofilms were evaluated by scanning electron microscopy and fluorescence microscopy. Addition of DNA at a low concentration (<1·0 μg ml(-1)) significantly increased biofilm mass of all three Candida species. In contrast, the addition of DNA at a high concentration (10 μg ml(-1)) decreased the biofilm mass. Interestingly, the formation of hyphae in a dense network of yeast cells was observed in C. albicans biofilms exposed to a low concentration of DNA (<1·0 μg ml(-1)). These findings demonstrated that extracellular DNA (eDNA) plays a crucial role in Candida biofilm formation and suggested that eDNA may induce the morphological transition from yeast to hyphal growth form during C. albicans biofilm development. A novel therapy targeting eDNA may be applicable for Candida infection to decrease biofilm formation and hyphal formation. © 2014 The Society for Applied Microbiology.

  2. Prospective evaluation of the chromogenic medium CandiSelect 4 for differentiation and presumptive identification of non-Candida albicans Candida species.

    PubMed

    Zhao, Liang; de Hoog, G Sybren; Cornelissen, Akke; Lyu, Qian; Mou, Lili; Liu, Taohua; Cao, Yu; Vatanshenassan, Mansoureh; Kang, Yingqian

    2016-02-01

    Rapid identification of pathogenic yeasts is a crucial step in timely and appropriate antifungal therapy. For diagnostics in the clinical laboratory, simplified alternatives to barcoding are needed. CandiSelect 4 (CS4) medium, a chromogenic medium for isolation of clinical yeasts, allows routine recognition of Candida albicans and presumptive identification of Candida tropicalis, Candida glabrata, and Candida krusei. We evaluated an extension of this method with 46 non-Candida albicans Candida (NCAC) and 7 Malassezia species. The medium supported growth of all species tested and a wide diversity of cultural types were observed. Colony colours were in violet, turquoise (including green and blue), or white tinges. Eight NCAC species produced violet pigmentation similar to that of C. albicans. Most NCAC species, including C. glabrata and C. tropicalis were distributed in the turquoise group. Malassezia species were invariably blue.

  3. Imaging morphogenesis of Candida albicans during infection in a live animal

    NASA Astrophysics Data System (ADS)

    Mitra, Soumya; Dolan, Kristy; Foster, Thomas H.; Wellington, Melanie

    2010-01-01

    Candida albicans is an opportunistic human fungal pathogen that requires an intact host immune response to prevent disease. Thus, studying host-pathogen interactions is critical to understanding and preventing this disease. We report a new model infection system in which ongoing C. albicans infections can be imaged at high spatial resolution in the ears of living mice. Intradermal inoculation into mouse ears with a C. albicans strain expressing green fluorescent protein results in systemic C. albicans infection that can be imaged in vivo using confocal microscopy. We observed filamentous growth of the organism in vivo as well as formation of microabscesses. This model system will allow us to gain significant new information about C. albicans pathogenesis through studies of host-C. albicans interactions in the native environment.

  4. Rapid identification of Candida albicans by using Albicans ID and fluoroplate agar plates.

    PubMed Central

    Rousselle, P; Freydiere, A M; Couillerot, P J; de Montclos, H; Gille, Y

    1994-01-01

    Two commercially available agar media, Albicans ID and Fluoroplate, that use a chromogenic or a fluorogenic substrate for the detection and identification of Candida albicans were evaluated. From 1,006 clinical samples containing 723 yeast strains, 352 C. albicans strains were detected with either of the two media. The sensitivity of each of the two media was 93.8% and the specificity was 98.6%, with five false-positive reactions for Candida tropicalis and no false-negative reactions. PMID:7883894

  5. Intra-amniotic Candida albicans infection induces mucosal injury and inflammation in the ovine fetal intestine

    PubMed Central

    Nikiforou, Maria; Jacobs, Esmee M.R.; Kemp, Matthew W.; Hornef, Mathias W.; Payne, Matthew S.; Saito, Masatoshi; Newnham, John P.; Janssen, Leon E.W.; Jobe, Alan H.; Kallapur, Suhas G.; Kramer, Boris W.; Wolfs, Tim G.A.M.

    2016-01-01

    Chorioamnionitis is caused by intrauterine infection with microorganisms including Candida albicans (C.albicans). Chorioamnionitis is associated with postnatal intestinal pathologies including necrotizing enterocolitis. The underlying mechanisms by which intra-amniotic C.albicans infection adversely affects the fetal gut remain unknown. Therefore, we assessed whether intra-amniotic C.albicans infection would cause intestinal inflammation and mucosal injury in an ovine model. Additionally, we tested whether treatment with the fungistatic fluconazole ameliorated the adverse intestinal outcome of intra-amniotic C.albicans infection. Pregnant sheep received intra-amniotic injections with 107 colony-forming units C.albicans or saline at 3 or 5 days before preterm delivery at 122 days of gestation. Fetuses were given intra-amniotic and intra-peritoneal fluconazole treatments 2 days after intra-amniotic administration of C.albicans. Intra-amniotic C.albicans caused intestinal colonization and invasive growth within the fetal gut with mucosal injury and intestinal inflammation, characterized by increased CD3+ lymphocytes, MPO+ cells and elevated TNF-α and IL-17 mRNA levels. Fluconazole treatment in utero decreased intestinal C.albicans colonization, mucosal injury but failed to attenuate intestinal inflammation. Intra-amniotic C.albicans caused intestinal infection, injury and inflammation. Fluconazole treatment decreased mucosal injury but failed to ameliorate C.albicans-mediated mucosal inflammation emphasizing the need to optimize the applied antifungal therapeutic strategy. PMID:27411776

  6. Intra-amniotic Candida albicans infection induces mucosal injury and inflammation in the ovine fetal intestine.

    PubMed

    Nikiforou, Maria; Jacobs, Esmee M R; Kemp, Matthew W; Hornef, Mathias W; Payne, Matthew S; Saito, Masatoshi; Newnham, John P; Janssen, Leon E W; Jobe, Alan H; Kallapur, Suhas G; Kramer, Boris W; Wolfs, Tim G A M

    2016-07-14

    Chorioamnionitis is caused by intrauterine infection with microorganisms including Candida albicans (C.albicans). Chorioamnionitis is associated with postnatal intestinal pathologies including necrotizing enterocolitis. The underlying mechanisms by which intra-amniotic C.albicans infection adversely affects the fetal gut remain unknown. Therefore, we assessed whether intra-amniotic C.albicans infection would cause intestinal inflammation and mucosal injury in an ovine model. Additionally, we tested whether treatment with the fungistatic fluconazole ameliorated the adverse intestinal outcome of intra-amniotic C.albicans infection. Pregnant sheep received intra-amniotic injections with 10(7) colony-forming units C.albicans or saline at 3 or 5 days before preterm delivery at 122 days of gestation. Fetuses were given intra-amniotic and intra-peritoneal fluconazole treatments 2 days after intra-amniotic administration of C.albicans. Intra-amniotic C.albicans caused intestinal colonization and invasive growth within the fetal gut with mucosal injury and intestinal inflammation, characterized by increased CD3(+) lymphocytes, MPO(+) cells and elevated TNF-α and IL-17 mRNA levels. Fluconazole treatment in utero decreased intestinal C.albicans colonization, mucosal injury but failed to attenuate intestinal inflammation. Intra-amniotic C.albicans caused intestinal infection, injury and inflammation. Fluconazole treatment decreased mucosal injury but failed to ameliorate C.albicans-mediated mucosal inflammation emphasizing the need to optimize the applied antifungal therapeutic strategy.

  7. Candida albicans Secreted Aspartyl Proteinases in Virulence and Pathogenesis

    PubMed Central

    Naglik, Julian R.; Challacombe, Stephen J.; Hube, Bernhard

    2003-01-01

    Candida albicans is the most common fungal pathogen of humans and has developed an extensive repertoire of putative virulence mechanisms that allows successful colonization and infection of the host under suitable predisposing conditions. Extracellular proteolytic activity plays a central role in Candida pathogenicity and is produced by a family of 10 secreted aspartyl proteinases (Sap proteins). Although the consequences of proteinase secretion during human infections is not precisely known, in vitro, animal, and human studies have implicated the proteinases in C. albicans virulence in one of the following seven ways: (i) correlation between Sap production in vitro and Candida virulence, (ii) degradation of human proteins and structural analysis in determining Sap substrate specificity, (iii) association of Sap production with other virulence processes of C. albicans, (iv) Sap protein production and Sap immune responses in animal and human infections, (v) SAP gene expression during Candida infections, (vi) modulation of C. albicans virulence by aspartyl proteinase inhibitors, and (vii) the use of SAP-disrupted mutants to analyze C. albicans virulence. Sap proteins fulfill a number of specialized functions during the infective process, which include the simple role of digesting molecules for nutrient acquisition, digesting or distorting host cell membranes to facilitate adhesion and tissue invasion, and digesting cells and molecules of the host immune system to avoid or resist antimicrobial attack by the host. We have critically discussed the data relevant to each of these seven criteria, with specific emphasis on how this proteinase family could contribute to Candida virulence and pathogenesis. PMID:12966142

  8. Early detection of Candida albicans biofilms at porous electrodes.

    PubMed

    Congdon, Robert B; Feldberg, Alexander S; Ben-Yakar, Natalie; McGee, Dennis; Ober, Christopher; Sammakia, Bahgat; Sadik, Omowunmi A

    2013-02-15

    We describe the development of an electrochemical sensor for early detection of biofilm using Candida albicans. The electrochemical sensor used the ability of biofilms to accept electrons from redox mediators relative to the number of metabolically active cells present. Cyclic voltammetry and differential pulse voltammetry techniques were used to monitor the redox reaction of K(3)Fe(CN)(6) at porous reticulated vitreous carbon (RVC) (238.7 cm(2)) working electrodes versus Ag/AgCl reference. A shift in the peak potential occurred after 12 h of film growth, which is attributed to the presence of C. albicans. Moreover, the intensity of the ferricyanide reduction peak first increased as C. albicans deposited onto the porous electrodes at various growth times. The peak current subsequently decreased at extended periods of growth of 48 h. The reduction in peak current was attributed to the biofilm reaching its maximum growth thickness, which correlated with the maximum number of metabolically active cells. The observed diffusion coefficients for the bare RVC and biofilm-coated electrodes were 2.2 × 10(-3) and 7.0 × 10(-6) cm(2)/s, respectively. The increase in diffusivity from the bare electrode to the biofilm-coated electrode indicated some enhancement of electron transfer mediated by the biofilm to the porous electrode. Verification of the growth of biofilm was achieved using scanning electron microcopy and laser scanning confocal imaging microscopy. Validation with conventional plating techniques confirmed that the correlation (R(2) = 0.9392) could be achieved between the electrochemical sensors data and colony-forming units. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Global Identification of Biofilm-Specific Proteolysis in Candida albicans

    PubMed Central

    Winter, Michael B.; Salcedo, Eugenia C.; Lohse, Matthew B.; Hartooni, Nairi; Gulati, Megha; Sanchez, Hiram; Takagi, Julie; Hube, Bernhard; Andes, David R.

    2016-01-01

    ABSTRACT Candida albicans is a fungal species that is part of the normal human microbiota and also an opportunistic pathogen capable of causing mucosal and systemic infections. C. albicans cells proliferate in a planktonic (suspension) state, but they also form biofilms, organized and tightly packed communities of cells attached to a solid surface. Biofilms colonize many niches of the human body and persist on implanted medical devices, where they are a major source of new C. albicans infections. Here, we used an unbiased and global substrate-profiling approach to discover proteolytic activities produced specifically by C. albicans biofilms, compared to planktonic cells, with the goal of identifying potential biofilm-specific diagnostic markers and targets for therapeutic intervention. This activity-based profiling approach, coupled with proteomics, identified Sap5 (Candidapepsin-5) and Sap6 (Candidapepsin-6) as major biofilm-specific proteases secreted by C. albicans. Fluorogenic peptide substrates with selectivity for Sap5 or Sap6 confirmed that their activities are highly upregulated in C. albicans biofilms; we also show that these activities are upregulated in other Candida clade pathogens. Deletion of the SAP5 and SAP6 genes in C. albicans compromised biofilm development in vitro in standard biofilm assays and in vivo in a rat central venous catheter biofilm model. This work establishes secreted proteolysis as a promising enzymatic marker and potential therapeutic target for Candida biofilm formation. PMID:27624133

  10. In Vitro Activity of Miltefosine against Candida albicans under Planktonic and Biofilm Growth Conditions and In Vivo Efficacy in a Murine Model of Oral Candidiasis

    PubMed Central

    Chaturvedi, Ashok K.; Rozental, Sonia

    2015-01-01

    The generation of a new antifungal against Candida albicans biofilms has become a major priority, since biofilm formation by this opportunistic pathogenic fungus is usually associated with an increased resistance to azole antifungal drugs and treatment failures. Miltefosine is an alkyl phospholipid with promising antifungal activity. Here, we report that, when tested under planktonic conditions, miltefosine displays potent in vitro activity against multiple fluconazole-susceptible and -resistant C. albicans clinical isolates, including isolates overexpressing efflux pumps and/or with well-characterized Erg11 mutations. Moreover, miltefosine inhibits C. albicans biofilm formation and displays activity against preformed biofilms. Serial passage experiments confirmed that miltefosine has a reduced potential to elicit resistance, and screening of a library of C. albicans transcription factor mutants provided additional insight into the activity of miltefosine against C. albicans growing under planktonic and biofilm conditions. Finally, we demonstrate the in vivo efficacy of topical treatment with miltefosine in the murine model of oropharyngeal candidiasis. Overall, our results confirm the potential of miltefosine as a promising antifungal drug candidate, in particular for the treatment of azole-resistant and biofilm-associated superficial candidiasis. PMID:26416861

  11. In Vitro Activity of Miltefosine against Candida albicans under Planktonic and Biofilm Growth Conditions and In Vivo Efficacy in a Murine Model of Oral Candidiasis.

    PubMed

    Vila, Taissa Vieira Machado; Chaturvedi, Ashok K; Rozental, Sonia; Lopez-Ribot, Jose L

    2015-12-01

    The generation of a new antifungal against Candida albicans biofilms has become a major priority, since biofilm formation by this opportunistic pathogenic fungus is usually associated with an increased resistance to azole antifungal drugs and treatment failures. Miltefosine is an alkyl phospholipid with promising antifungal activity. Here, we report that, when tested under planktonic conditions, miltefosine displays potent in vitro activity against multiple fluconazole-susceptible and -resistant C. albicans clinical isolates, including isolates overexpressing efflux pumps and/or with well-characterized Erg11 mutations. Moreover, miltefosine inhibits C. albicans biofilm formation and displays activity against preformed biofilms. Serial passage experiments confirmed that miltefosine has a reduced potential to elicit resistance, and screening of a library of C. albicans transcription factor mutants provided additional insight into the activity of miltefosine against C. albicans growing under planktonic and biofilm conditions. Finally, we demonstrate the in vivo efficacy of topical treatment with miltefosine in the murine model of oropharyngeal candidiasis. Overall, our results confirm the potential of miltefosine as a promising antifungal drug candidate, in particular for the treatment of azole-resistant and biofilm-associated superficial candidiasis.

  12. Candida dubliniensis and Candida albicans differentiation by colony morphotype in Sabouraud-triphenyltetrazolium agar.

    PubMed

    Gamarra, Soledad; Mancilla, Estefanía; Dudiuk, Catiana; Garcia-Effron, Guillermo

    2015-01-01

    Candida dubliniensis is a germ tube and chlamydoconidia producing Candida species that may be misidentified as Candida albicans. Molecular-based methods are the most reliable techniques for C. albicans and C. dubliniensis differentiation. However, accurate, quick and inexpensive phenotypic tests are needed to be used in low-complexity mycology laboratories. To evaluate colony morphotypes on Sabouraud-triphenyltetrazolium agar as a tool for C. dubliniensis and C. albicans differentiation. The morphology of 126 C. albicans and C. dubliniensis strains was evaluated and compared with their identification by molecular methods. The method showed 100% sensitivity and specificity when color and the presence or absence of large white mycelial halo was evaluated. Colony morphotype on Sabouraud-triphenyltetrazolium agar should be considered as a new tool to differentiate C. dubliniensis and C. albicans. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  13. Comparison of the effect of honey and miconazole against Candida albicans in vitro.

    PubMed

    Banaeian-Borujeni, Shayeste; Mobini, Gholam R; Pourgheysari, Batoul; Validi, Majid

    2013-01-01

    One of the most common causes of vaginitis is candidiasis. The aim of this study is to compare the effect of honey and miconazole against Candida albicans, in vitro. The different W/V concentrations of honey were prepared at 20, 40, 60, 80, and 95% and different dilutions of miconazole were prepared in 0.05, 5, and 50 μg/ml. A microdilution of 100/000 cells per ml of a two-day old culture of Candida albicans was prepared in normal saline, after culturing the strain of PTCC 5027 in RPMI 1640 medium. Ten microliters of this dilution was added to 1 ml of the RPMI 1640 medium containing different concentrations of honey and to 1 ml of the RPMI 1640 medium containing different dilutions of miconazole. The cultures were incubated at 35°C for 12, 24, and 48 hours. The growth rate of Candida albicans was determined in the cultures. The results indicated that the honey prevented the growth of C. albicans greatly only at an 80% concentration, whereas, miconazole inhibited it completely. As Candida albicans is a normal vaginal flora, the inhibitory effect of honey without the fungicide effect is a very good trend in the treatment of vaginal candidiasis.

  14. Comparison of the effect of honey and miconazole against Candida albicans in vitro

    PubMed Central

    Banaeian-Borujeni, Shayeste; Mobini, Gholam R.; Pourgheysari, Batoul; Validi, Majid

    2013-01-01

    Background: One of the most common causes of vaginitis is candidiasis. The aim of this study is to compare the effect of honey and miconazole against Candida albicans, in vitro. Materials and Methods: The different W/V concentrations of honey were prepared at 20, 40, 60, 80, and 95% and different dilutions of miconazole were prepared in 0.05, 5, and 50 μg/ml. A microdilution of 100/000 cells per ml of a two-day old culture of Candida albicans was prepared in normal saline, after culturing the strain of PTCC 5027 in RPMI 1640 medium. Ten microliters of this dilution was added to 1 ml of the RPMI 1640 medium containing different concentrations of honey and to 1 ml of the RPMI 1640 medium containing different dilutions of miconazole. The cultures were incubated at 35°C for 12, 24, and 48 hours. Results: The growth rate of Candida albicans was determined in the cultures. The results indicated that the honey prevented the growth of C. albicans greatly only at an 80% concentration, whereas, miconazole inhibited it completely. Conclusions: As Candida albicans is a normal vaginal flora, the inhibitory effect of honey without the fungicide effect is a very good trend in the treatment of vaginal candidiasis. PMID:24223372

  15. Hsp21 Potentiates Antifungal Drug Tolerance in Candida albicans

    PubMed Central

    Mayer, François L.; Wilson, Duncan; Hube, Bernhard

    2013-01-01

    Systemic infections of humans with the fungal pathogen Candida albicans are associated with a high mortality rate. Currently, efficient treatment of these infections is hampered by the relatively low number of available antifungal drugs. We recently identified the small heat shock protein Hsp21 in C. albicans and demonstrated its fundamental role for environmental stress adaptation and fungal virulence. Hsp21 was found in several pathogenic Candida species but not in humans. This prompted us to investigate the effects of a broad range of different antifungal drugs on an Hsp21-null C. albicans mutant strain. Our results indicate that combinatorial therapy targeting Hsp21, together with specific antifungal drug targets, has strong synergistic potential. In addition, we demonstrate that Hsp21 is required for tolerance to ethanol-induced stress and induction of filamentation in response to pharmacological inhibition of Hsp90. These findings might pave the way for the development of new treatment strategies against Candida infections. PMID:23533680

  16. Innate immune cell response upon Candida albicans infection

    PubMed Central

    Qin, Yulin; Zhang, Lulu; Xu, Zheng; Zhang, Jinyu; Jiang, Yuan-ying; Cao, Yongbing; Yan, Tianhua

    2016-01-01

    abstract Candida albicans is a polymorphic fungus which is the predominant cause of superficial and deep tissue fungal infections. This microorganism has developed efficient strategies to invade the host and evade host defense systems. However, the host immune system will be prepared for defense against the microbe by recognition of receptors, activation of signal transduction pathways and cooperation of immune cells. As a consequence, C. albicans could either be eliminated by immune cells rapidly or disseminate hematogenously, leading to life-threatening systemic infections. The interplay between Candida albicans and the host is complex, requiring recognition of the invaded pathogens, activation of intricate pathways and collaboration of various immune cells. In this review, we will focus on the effects of innate immunity that emphasize the first line protection of host defense against invaded C. albicans including the basis of receptor-mediated recognition and the mechanisms of cell-mediated immunity. PMID:27078171

  17. Innate immune cell response upon Candida albicans infection.

    PubMed

    Qin, Yulin; Zhang, Lulu; Xu, Zheng; Zhang, Jinyu; Jiang, Yuan-Ying; Cao, Yongbing; Yan, Tianhua

    2016-07-03

    Candida albicans is a polymorphic fungus which is the predominant cause of superficial and deep tissue fungal infections. This microorganism has developed efficient strategies to invade the host and evade host defense systems. However, the host immune system will be prepared for defense against the microbe by recognition of receptors, activation of signal transduction pathways and cooperation of immune cells. As a consequence, C. albicans could either be eliminated by immune cells rapidly or disseminate hematogenously, leading to life-threatening systemic infections. The interplay between Candida albicans and the host is complex, requiring recognition of the invaded pathogens, activation of intricate pathways and collaboration of various immune cells. In this review, we will focus on the effects of innate immunity that emphasize the first line protection of host defense against invaded C. albicans including the basis of receptor-mediated recognition and the mechanisms of cell-mediated immunity.

  18. Delicate Metabolic Control and Coordinated Stress Response Critically Determine Antifungal Tolerance of Candida albicans Biofilm Persisters

    PubMed Central

    Li, Peng; Alpi, Emanuele; Vizcaino, Juan A.

    2015-01-01

    Candida infection has emerged as a critical health care burden worldwide, owing to the formation of robust biofilms against common antifungals. Recent evidence shows that multidrug-tolerant persisters critically account for biofilm recalcitrance, but their underlying biological mechanisms are poorly understood. Here, we first investigated the phenotypic characteristics of Candida biofilm persisters under consecutive harsh treatments of amphotericin B. The prolonged treatments effectively killed the majority of the cells of biofilms derived from representative strains of Candida albicans, Candida glabrata, and Candida tropicalis but failed to eradicate a small fraction of persisters. Next, we explored the tolerance mechanisms of the persisters through an investigation of the proteomic profiles of C. albicans biofilm persister fractions by liquid chromatography-tandem mass spectrometry. The C. albicans biofilm persisters displayed a specific proteomic signature, with an array of 205 differentially expressed proteins. The crucial enzymes involved in glycolysis, the tricarboxylic acid cycle, and protein synthesis were markedly downregulated, indicating that major metabolic activities are subdued in the persisters. It is noteworthy that certain metabolic pathways, such as the glyoxylate cycle, were able to be activated with significantly increased levels of isocitrate lyase and malate synthase. Moreover, a number of important proteins responsible for Candida growth, virulence, and the stress response were greatly upregulated. Interestingly, the persisters were tolerant to oxidative stress, despite highly induced intracellular superoxide. The current findings suggest that delicate metabolic control and a coordinated stress response may play a crucial role in mediating the survival and antifungal tolerance of Candida biofilm persisters. PMID:26195524

  19. Endocarditis due to a co-infection of Candida albicans and Candida tropicalis in a drug abuser.

    PubMed

    Fesharaki, Shirinsadat Hashemi; Haghani, Iman; Mousavi, Bita; Kargar, Melika Laal; Boroumand, Mohammadali; Anvari, Maryam Sotoudeh; Abbasi, Kyomars; Meis, Jacques F; Badali, Hamid

    2013-11-01

    In recent decades the incidence of Candida endocarditis has increased dramatically. Despite the application of surgery and antifungal therapy, Candida endocarditis remains a life-threatening infection with significant morbidity and mortality. We report a 37-year-old male drug abuser presenting with high fever, chest pain, loss of appetite and cardiac failure. His echocardiography revealed mobile large tricuspid valve vegetations. Fungal endocarditis was confirmed by culturing of the resected vegetation showing mixed growth of Candida albicans and Candida tropicalis, although three consecutive blood cultures were negative for Candida species. Phenotypic identification was reconfirmed by sequencing of the internal transcribed spacer (ITS rDNA) region. The patient was initially treated with intravenous fluconazole (6 mg kg(-1) per day), followed by 2 weeks of intravenous amphotericin B deoxycholate (1 mg kg(-1) per day). Although MICs were low for both drugs, the patient's antifungal therapy combined with valve replacement failed, and he died due to respiratory failure.

  20. Isolation and characterization of yeast monomorphic mutants of Candida albicans.

    PubMed Central

    Elorza, M V; Sentandreu, R; Ruiz-Herrera, J

    1994-01-01

    A method was devised for the isolation of yeast monomorphic (LEV) mutants of Candida albicans. By this procedure, about 20 stable yeast-like mutants were isolated after mutagenesis with ethyl methane sulfonate. The growth rate of the mutants in different carbon sources, both fermentable and not, was indistinguishable from that of the parental strain, but they were unable to grow as mycelial forms after application of any of the common effective inducers, i.e., heat shock, pH alterations, proline addition, or use of GlcNAc as the carbon source. Studies performed with one selected strain demonstrated that it had severe alterations in the chemical composition of the cell wall, mainly in the levels of chitin and glucans, and in specific mannoproteins, some of them recognizable by specific polyclonal and monoclonal antibodies. It is suggested that these structural alterations hinder the construction of a normal hyphal wall. Images PMID:8157600

  1. Global Identification of Biofilm-Specific Proteolysis in Candida albicans.

    PubMed

    Winter, Michael B; Salcedo, Eugenia C; Lohse, Matthew B; Hartooni, Nairi; Gulati, Megha; Sanchez, Hiram; Takagi, Julie; Hube, Bernhard; Andes, David R; Johnson, Alexander D; Craik, Charles S; Nobile, Clarissa J

    2016-09-13

    Candida albicans is a fungal species that is part of the normal human microbiota and also an opportunistic pathogen capable of causing mucosal and systemic infections. C. albicans cells proliferate in a planktonic (suspension) state, but they also form biofilms, organized and tightly packed communities of cells attached to a solid surface. Biofilms colonize many niches of the human body and persist on implanted medical devices, where they are a major source of new C. albicans infections. Here, we used an unbiased and global substrate-profiling approach to discover proteolytic activities produced specifically by C. albicans biofilms, compared to planktonic cells, with the goal of identifying potential biofilm-specific diagnostic markers and targets for therapeutic intervention. This activity-based profiling approach, coupled with proteomics, identified Sap5 (Candidapepsin-5) and Sap6 (Candidapepsin-6) as major biofilm-specific proteases secreted by C. albicans Fluorogenic peptide substrates with selectivity for Sap5 or Sap6 confirmed that their activities are highly upregulated in C. albicans biofilms; we also show that these activities are upregulated in other Candida clade pathogens. Deletion of the SAP5 and SAP6 genes in C. albicans compromised biofilm development in vitro in standard biofilm assays and in vivo in a rat central venous catheter biofilm model. This work establishes secreted proteolysis as a promising enzymatic marker and potential therapeutic target for Candida biofilm formation. Biofilm formation by the opportunistic fungal pathogen C. albicans is a major cause of life-threatening infections. This work provides a global characterization of secreted proteolytic activity produced specifically by C. albicans biofilms. We identify activity from the proteases Sap5 and Sap6 as highly upregulated during C. albicans biofilm formation and develop Sap-cleavable fluorogenic substrates that enable the detection of biofilms from C. albicans and also

  2. [Evaluation of a new chromogenic medium (Candida ID) for the isolation and presumptive identification of Candida albicans and other medically important yeasts].

    PubMed

    Quindós, G; Alonso-Vargas, R; Helou, S; Arechavala, A; Martín-Mazuelos, E; Negroni, R

    2001-03-01

    Candidiasis is a frequent human infection caused mainly by Candida albicans. However, other species are emerging as important pathogens, as Candida glabrata, Candida parapsilosis, Candida tropicalis, Candida krusei or Candida guilliermondii. Rapid identification of clinical isolates could facilitate diagnosis and treatment. Candida ID (bioMerieux, Spain) is a new medium for the isolation and presumptive identification of yeasts: C. albicans grows as blue colonies, and C. tropicalis, C. guilliermondii, Candida kefyr and Candida lusitaniae as pink ones. The utility of Candida ID was evaluated with more than 700 clinical isolates and type culture collection strains from different genera including Candida, Cryptococcus, Saccharomyces, and Rhodotorula. Presumptive identification was confirmed by germ tube test, microscopic morphology and chlamydoconidia production on corn meal agar and carbohydrate assimilation on API-ATB ID 32C or Vitek (bioMerieux). Growth on Candida ID was rapid (18-24 h) for most of the yeast strains tested. Sensitivity and specificity of identification of C. albicans was significantly high (>98%), since a very low number of isolates were found to be false negative or false positive. A better result was obtained for species growing as pink colonies (>99.5%). Detection of different species of medical important yeasts was easy with Candida ID, as perfectly distinct colors and textures of colonies were observed on this medium. Candida ID allowed the discrimination between C. glabrata (creamy and smooth) and C. krusei (rough and white) colonies. Other species showed different colony textures and colours, white being the predominant colour. Candida ID was very useful for the presumptive identification C. albicans isolates.

  3. Biofilms of non-Candida albicans Candida species: quantification, structure and matrix composition.

    PubMed

    Silva, Sónia; Henriques, Mariana; Martins, António; Oliveira, Rosário; Williams, David; Azeredo, Joana

    2009-11-01

    Most cases of candidiasis have been attributed to C. albicans, but recently, non- Candida albicans Candida (NCAC) species have been identified as common pathogens. The ability of Candida species to form biofilms has important clinical repercussions due to their increased resistance to antifungal therapy and the ability of yeast cells within the biofilms to withstand host immune defenses. Given this clinical importance of the biofilm growth form, the aim of this study was to characterize biofilms produced by three NCAC species, namely C. parapsilosis, C. tropicalis and C. glabrata. The biofilm forming ability of clinical isolates of C. parapsilosis, C. tropicalis and C. glabrata recovered from different sources, was evaluated by crystal violet staining. The structure and morphological characteristics of the biofilms were also assessed by scanning electron microscopy and the biofilm matrix composition analyzed for protein and carbohydrate content. All NCAC species were able to form biofilms although these were less extensive for C. glabrata compared with C. parapsilosis and C. tropicalis. It was evident that C. parapsilosis biofilm production was highly strain dependent, a feature not evident with C. glabrata and C. tropicalis. Scanning electron microscopy revealed structural differences for biofilms with respect to cell morphology and spatial arrangement. Candida parapsilosis biofilm matrices had large amounts of carbohydrate with less protein. Conversely, matrices extracted from C. tropicalis biofilms had low amounts of carbohydrate and protein. Interestingly, C. glabrata biofilm matrix was high in both protein and carbohydrate content. The present work demonstrates that biofilm forming ability, structure and matrix composition are highly species dependent with additional strain variability occurring with C. parapsilosis.

  4. Sensitization of Candida albicans to terbinafine by berberine and berberrubine

    PubMed Central

    LAM, PIKLING; KOK, STANTON HON LUNG; LEE, KENNETH KA HO; LAM, KIM HUNG; HAU, DESMOND KWOK PO; WONG, WAI YEUNG; BIAN, ZHAOXIANG; GAMBARI, ROBERTO; CHUI, CHUNG HIN

    2016-01-01

    Candida albicans (C. albicans) is an opportunistic fungal pathogen, particularly observed in immunocompromised patients. C. albicans accounts for 50–70% of cases of invasive candidiasis in the majority of clinical settings. Terbinafine, an allylamine antifungal drug, has been used to treat fungal infections previously. It has fungistatic activity against C. albicans. Traditional Chinese medicines can be used as complementary medicines to conventional drugs to treat a variety of ailments and diseases. Berberine is a quaternary alkaloid isolated from the traditional Chinese herb, Coptidis Rhizoma, while berberrubine is isolated from the medicinal plant Berberis vulgaris, but is also readily derived from berberine by pyrolysis. The present study demonstrates the possible complementary use of berberine and berberrubine with terbinafine against C. albicans. The experimental findings assume that the potential application of these alkaloids together with reduced dosage of the standard drug would enhance the resulting antifungal potency. PMID:27073630

  5. Prevalence of yeast other than Candida albicans in denture wearers.

    PubMed

    Cavaleiro, Inês; Proença, Luis; Félix, Sérgio; Salema-Oom, Madalena

    2013-07-01

    The isolation of yeast species other than Candida albicans from the oral mucosa has been increasing in frequency, suggesting that those may constitute emerging potential oral colonizers. The purpose of this work was to determine whether yeast species other than C. albicans are associated with factors related to wearing of dental prostheses. tRNA-PCR fingerprinting and sequencing of the 26S rDNA D1/D2 domain were used to identify all yeasts isolated from CHROMagar™ Candida cultures of oral swabs collected from 178 patients. Besides C. albicans, 13 other species were identified, corresponding to 34% of the yeast isolates. The majority of the non-C. albicans species were not detected as single colonizers but rather in co-colonization with one or two other yeasts, often with C. albicans. No significant associations were found with non-C. albicans species. On the contrary, the best-fitted logistic regression model predicts that either wearing a denture (adjusted odds = 4.6) or insufficient oral hygiene (adjusted odds = 2.3) are risks for colonization by yeast, in general. The colonization with non-C. albicans species and co-colonization were not independently associated with any of the analyzed host-related factors. In particular, neither wearing a removable denture nor being elderly were significant predictors. © 2012 by the American College of Prosthodontists.

  6. Evaluation of Bichro-Dubli Fumouze to distinguish Candida dubliniensis from Candida albicans.

    PubMed

    Sahand, Ismail H; Moragues, María D; Robert, Raymond; Quindós, Guillermo; Pontón, José

    2006-06-01

    We have evaluated the ability of the Bichro-Dubli Fumouze (Fumouze Diagnostics, Levallois-Perret, France) latex agglutination test to identify colonies of Candida dubliniensis grown on different media. The test was positive for 103 of 106 isolates of C. dubliniensis and negative for Candida albicans and other Candida species studied. The sensitivity and specificity of the test were 97.1% and 100%, respectively. The test is very rapid, simple, and reliable giving the same results independently of whether the colonies are grown previously on Sabouraud dextrose agar, CHROMagar Candida medium, Candida ID2 medium, or CHROMagar-Pal's medium.

  7. Anti-fungal activity of Morinda citrifolia (noni) extracts against Candida albicans: an in vitro study.

    PubMed

    Barani, K; Manipal, Sunayana; Prabu, D; Ahmed, Adil; Adusumilli, Preethi; Jeevika, C

    2014-01-01

    The aim of this study was to investigate the anti-fungal activity of Morinda citrifolia fruit extract on Candida albicans. Juice extract from M. citrifolia fruit was lyophilized and used in anti-fungal testing. Anti-fungal activity of M. citrifolia fruit extract against C. albicans was tested in vitro at various concentrations. The inhibitory effect of M. citrifolia extract on C. albicans was determined by agar culture and applied broth dilution test. M. citrifolia extract at 1000 μg/ml concentration effectively inhibited the growth of C. albicans (16.6 ± 0.3) compared with the positive control - amphotericin B (20.6 ± 0.6). It was found to be a dose-dependent reaction. M. citrifolia fruit extract had an anti-fungal effect on C. albicans and the inhibitory effect varied with concentration.

  8. Recurrent episodes of Candidemia due to Candida glabrata, Candida tropicalis and Candida albicans with acquired echinocandin resistance.

    PubMed

    Grosset, Marine; Desnos-Ollivier, Marie; Godet, Cendrine; Kauffmann-Lacroix, Catherine; Cazenave-Roblot, France

    2016-12-01

    Mixed fungal infection and acquired echinocandin resistance of Candida spp. remain infrequent. In this study we have reported the case of a patient hospitalized for tuberculosis who experienced multiple infections due to three common Candida species (C. albicans, C. glabrata, C. tropicalis). Furthermore, consecutive isolates from blood cultures and heart valve were found resistant to azoles (C. tropicalis) and to echinocandin with either novel (C. tropicalis) or previously described (C. albicans) missense mutations in the Fks gene.

  9. Essential Role for Vacuolar Acidification in Candida albicans Virulence*

    PubMed Central

    Patenaude, Cassandra; Zhang, Yongqiang; Cormack, Brendan; Köhler, Julia; Rao, Rajini

    2013-01-01

    Fungal infections are on the rise, with mortality above 30% in patients with septic Candida infections. Mutants lacking V-ATPase activity are avirulent and fail to acidify endomembrane compartments, exhibiting pleiotropic defects in secretory, endosomal, and vacuolar pathways. However, the individual contribution of organellar acidification to virulence and its associated traits is not known. To dissect their separate roles in Candida albicans pathogenicity we generated knock-out strains for the V0 subunit a genes VPH1 and STV1, which target the vacuole and secretory pathway, respectively. While the two subunits were redundant in many vma phenotypes, such as alkaline pH sensitivity, calcium homeostasis, respiratory defects, and cell wall integrity, we observed a unique contribution of VPH1. Specifically, vph1Δ was defective in acidification of the vacuole and its dependent functions, such as metal ion sequestration as evidenced by hypersensitivity to Zn2+ toxicity, whereas stv1Δ resembled wild type. In growth conditions that elicit morphogenic switching, vph1Δ was defective in forming hyphae whereas stv1Δ was normal or only modestly impaired. Host cell interactions were evaluated in vitro using the Caco-2 model of intestinal epithelial cells, and murine macrophages. Like wild type, stv1Δ was able to inflict cellular damage in Caco-2 and macrophage cells, as assayed by LDH release, and escape by filamentation. In contrast, vph1Δ resembled a vma7Δ mutant, with significant attenuation in host cell damage. Finally, we show that VPH1 is required for fungal virulence in a murine model of systemic infection. Our results suggest that vacuolar acidification has an essential function in the ability of C. albicans to form hyphae and establish infection. PMID:23884420

  10. Virulence of Candida albicans isolated from HIV infected and non infected individuals.

    PubMed

    Wibawa, Tri; Praseno; Aman, Abu Tholib

    2015-01-01

    Candida sp contributes 33.1 % of fungal infections among HIV patients. Among the species of the genus Candida, Candida albicans is the most frequently isolated from HIV patients. This study aimed to analyze putative virulence factors of C. albicans isolated from oral cavities of HIV infected patients and healthy individuals. Twenty isolates from HIV infected patients and fourteen from healthy individuals were analyzed for phenotypic switching, cell growth rate, hyphae formation, hemolytic activity and biofilm formation characteristics. The frequency of phenotypic switching was low in both groups. The cell growth rate of C. albicans from HIV infected patients were significantly higher than those from healthy individuals (p < 0.001). After 48 h incubation, the concentration of C. albicans isolated from HIV infected patients was 8.6 × 10(6) cells/ml while the concentration of C. albicans isolated from healthy individuals was 7.8 × 10(6) cells/ml. After 72 h incubation, the concentration of C. albicans isolated from HIV infected patients was 9.5 × 10(6) cells/ml while the concentration of C. albicans isolated from healthy individuals was 8.2 × 10(6) cells/ml. In contrast, the hemolytic activity of C. albicans isolated from healthy individuals were significantly higher compared to those from HIV infected patients (p < 0.001) at both aerobic (6 vs. 3.5 mm) and anaerobic (3.8 vs. 1.3 mm) conditions. The percentages of hyphae forming cells were higher in C. albicans collected from HIV infected patients (27.5 %) compared to the healthy individual group (14.7 %). However, this trend was not statistically significant (p = 0.1). Candida albicans isolated from HIV infected patients have similar ability to develop biofilms compared to those from healthy individuals. (OR = 4.2; 95 % CI 0.724-26.559). The virulence factors of C. albicans isolated from HIV infected patients were not significantly different from those of healthy individuals. The results

  11. Biofilm Matrix Regulation by Candida albicans Zap1

    PubMed Central

    Nobile, Clarissa J.; Nett, Jeniel E.; Hernday, Aaron D.; Homann, Oliver R.; Deneault, Jean-Sebastien; Nantel, Andre; Andes, David R.; Johnson, Alexander D.; Mitchell, Aaron P.

    2009-01-01

    A biofilm is a surface-associated population of microorganisms embedded in a matrix of extracellular polymeric substances. Biofilms are a major natural growth form of microorganisms and the cause of pervasive device-associated infection. This report focuses on the biofilm matrix of Candida albicans, the major fungal pathogen of humans. We report here that the C. albicans zinc-response transcription factor Zap1 is a negative regulator of a major matrix component, soluble β-1,3 glucan, in both in vitro and in vivo biofilm models. To understand the mechanistic relationship between Zap1 and matrix, we identified Zap1 target genes through expression profiling and full genome chromatin immunoprecipitation. On the basis of these results, we designed additional experiments showing that two glucoamylases, Gca1 and Gca2, have positive roles in matrix production and may function through hydrolysis of insoluble β-1,3 glucan chains. We also show that a group of alcohol dehydrogenases Adh5, Csh1, and Ifd6 have roles in matrix production: Adh5 acts positively, and Csh1 and Ifd6, negatively. We propose that these alcohol dehydrogenases generate quorum-sensing aryl and acyl alcohols that in turn govern multiple events in biofilm maturation. Our findings define a novel regulatory circuit and its mechanism of control of a process central to infection. PMID:19529758

  12. The Pathogen Candida albicans Hijacks Pyroptosis for Escape from Macrophages

    PubMed Central

    Uwamahoro, Nathalie; Verma-Gaur, Jiyoti; Shen, Hsin-Hui; Qu, Yue; Lewis, Rowena; Lu, Jingxiong; Bambery, Keith; Masters, Seth L.; Vince, James E.; Naderer, Thomas; Traven, Ana

    2014-01-01

    ABSTRACT The fungal pathogen Candida albicans causes macrophage death and escapes, but the molecular mechanisms remained unknown. Here we used live-cell imaging to monitor the interaction of C. albicans with macrophages and show that C. albicans kills macrophages in two temporally and mechanistically distinct phases. Early upon phagocytosis, C. albicans triggers pyroptosis, a proinflammatory macrophage death. Pyroptosis is controlled by the developmental yeast-to-hypha transition of Candida. When pyroptosis is inactivated, wild-type C. albicans hyphae cause significantly less macrophage killing for up to 8 h postphagocytosis. After the first 8 h, a second macrophage-killing phase is initiated. This second phase depends on robust hyphal formation but is mechanistically distinct from pyroptosis. The transcriptional regulator Mediator is necessary for morphogenesis of C. albicans in macrophages and the establishment of the wild-type surface architecture of hyphae that together mediate activation of macrophage cell death. Our data suggest that the defects of the Mediator mutants in causing macrophage death are caused, at least in part, by reduced activation of pyroptosis. A Mediator mutant that forms hyphae of apparently wild-type morphology but is defective in triggering early macrophage death shows a breakdown of cell surface architecture and reduced exposed 1,3 β-glucan in hyphae. Our report shows how Candida uses host and pathogen pathways for macrophage killing. The current model of mechanical piercing of macrophages by C. albicans hyphae should be revised to include activation of pyroptosis by hyphae as an important mechanism mediating macrophage cell death upon C. albicans infection. PMID:24667705

  13. Candida glabrata Binding to Candida albicans Hyphae Enables Its Development in Oropharyngeal Candidiasis

    PubMed Central

    Tati, Swetha; Davidow, Peter; McCall, Andrew; Hwang-Wong, Elizabeth; Rojas, Isolde G.; Cormack, Brendan; Edgerton, Mira

    2016-01-01

    Pathogenic mechanisms of Candida glabrata in oral candidiasis, especially because of its inability to form hyphae, are understudied. Since both Candida albicans and C. glabrata are frequently co-isolated in oropharyngeal candidiasis (OPC), we examined their co-adhesion in vitro and observed adhesion of C. glabrata only to C. albicans hyphae microscopically. Mice were infected sublingually with C. albicans or C. glabrata individually, or with both species concurrently, to study their ability to cause OPC. Infection with C. glabrata alone resulted in negligible infection of tongues; however, colonization by C. glabrata was increased by co-infection or a pre-established infection with C. albicans. Furthermore, C. glabrata required C. albicans for colonization of tongues, since decreasing C. albicans burden with fluconazole also reduced C. glabrata. C. albicans hyphal wall adhesins Als1 and Als3 were important for in vitro adhesion of C. glabrata and to establish OPC. C. glabrata cell wall protein coding genes EPA8, EPA19, AWP2, AWP7, and CAGL0F00181 were implicated in mediating adhesion to C. albicans hyphae and remarkably, their expression was induced by incubation with germinated C. albicans. Thus, we found a near essential requirement for the presence of C. albicans for both initial colonization and establishment of OPC infection by C. glabrata. PMID:27029023

  14. Candida glabrata Binding to Candida albicans Hyphae Enables Its Development in Oropharyngeal Candidiasis.

    PubMed

    Tati, Swetha; Davidow, Peter; McCall, Andrew; Hwang-Wong, Elizabeth; Rojas, Isolde G; Cormack, Brendan; Edgerton, Mira

    2016-03-01

    Pathogenic mechanisms of Candida glabrata in oral candidiasis, especially because of its inability to form hyphae, are understudied. Since both Candida albicans and C. glabrata are frequently co-isolated in oropharyngeal candidiasis (OPC), we examined their co-adhesion in vitro and observed adhesion of C. glabrata only to C. albicans hyphae microscopically. Mice were infected sublingually with C. albicans or C. glabrata individually, or with both species concurrently, to study their ability to cause OPC. Infection with C. glabrata alone resulted in negligible infection of tongues; however, colonization by C. glabrata was increased by co-infection or a pre-established infection with C. albicans. Furthermore, C. glabrata required C. albicans for colonization of tongues, since decreasing C. albicans burden with fluconazole also reduced C. glabrata. C. albicans hyphal wall adhesins Als1 and Als3 were important for in vitro adhesion of C. glabrata and to establish OPC. C. glabrata cell wall protein coding genes EPA8, EPA19, AWP2, AWP7, and CAGL0F00181 were implicated in mediating adhesion to C. albicans hyphae and remarkably, their expression was induced by incubation with germinated C. albicans. Thus, we found a near essential requirement for the presence of C. albicans for both initial colonization and establishment of OPC infection by C. glabrata.

  15. Susceptibility of Candida albicans from Cystic Fibrosis Patients.

    PubMed

    Sabino, Raquel; Carolino, Elisabete; Moss, Richard B; Banaei, Niaz; Verissimo, Cristina; Stevens, David A

    2017-04-18

    Candida albicans is a common microbe, colonizer and potential pathogen found in respiratory cultures of cystic fibrosis (CF) patients. Because of possible development of resistance in patient isolates resulting from residence in the abnormal milieu of CF patient airways, or from exposure to antifungals, and considering the possibility of patient-to-patient spread of microbes and reports of elevated resistance to other fungal pathogens, it was important to assay the susceptibility of isolates of Candida and compare that profile to isolates from the community. In our center, and unlike another fungal pathogen, no increase in resistance of Candida isolates of the CF cohort was found.

  16. Application of CHROMagar Candida for rapid screening of clinical specimens for Candida albicans, Candida tropicalis, Candida krusei, and Candida (Torulopsis) glabrata.

    PubMed Central

    Pfaller, M A; Houston, A; Coffmann, S

    1996-01-01

    CHROMagar Candida is a new differential culture medium that allows selective isolation of yeasts and simultaneously identifies colonies of Candida albicans, C. tropicalis, and C. krusei. We evaluated the use of this medium with 316 yeast isolates including 247 isolated directly on CHROMagar from clinical material. Over 95% of stock and clinical isolates of C. albicans, C. tropicalis, and C. krusei were correctly identified on the basis of colony morphology and pigmentation on CHROMagar. Additionally, CHROMagar also allowed the identification of C. (Torulopsis) glabrata at a similar level of accuracy. The overall agreement between two observers in reading the CHROMagar plates was 95%. Growth of Candida sp. isolates on CHROMagar had no adverse effect on antifungal MICs or Vitek identification results. In parallel, cultures of 548 stool and rectal swab specimens set up on CHROMagar and Sabouraud glucose agar (SGA) were positive in 234 instances. CHROMagar was positive and SGA was negative for 11 specimens, and CHROMagar was negative and SGA was positive for 18 specimens. A single yeast species was isolated on both media from 162 specimens, and in 146 (90%) of these specimens the same species was detected on both CHROMagar and SGA. A total of 43 of the 234 positive cultures contained mixtures of yeast species. Twenty (47%) of these mixed cultures were detected only on CHROMagar. CHROMagar is extremely useful in making a rapid presumptive identification of common yeast species. This capability plus the ability to detect mixed cultures of Candida spp. promises to improve and streamline the work flow in the mycology and clinical microbiology laboratory. PMID:8748273

  17. Development of a High-Throughput Candida albicans Biofilm Chip

    PubMed Central

    Srinivasan, Anand; Uppuluri, Priya; Lopez-Ribot, Jose; Ramasubramanian, Anand K.

    2011-01-01

    We have developed a high-density microarray platform consisting of nano-biofilms of Candida albicans. A robotic microarrayer was used to print yeast cells of C. albicans encapsulated in a collagen matrix at a volume as low as 50 nL onto surface-modified microscope slides. Upon incubation, the cells grow into fully formed “nano-biofilms”. The morphological and architectural complexity of these biofilms were evaluated by scanning electron and confocal scanning laser microscopy. The extent of biofilm formation was determined using a microarray scanner from changes in fluorescence intensities due to FUN 1 metabolic processing. This staining technique was also adapted for antifungal susceptibility testing, which demonstrated that, similar to regular biofilms, cells within the on-chip biofilms displayed elevated levels of resistance against antifungal agents (fluconazole and amphotericin B). Thus, results from structural analyses and antifungal susceptibility testing indicated that despite miniaturization, these biofilms display the typical phenotypic properties associated with the biofilm mode of growth. In its final format, the C. albicans biofilm chip (CaBChip) is composed of 768 equivalent and spatially distinct nano-biofilms on a single slide; multiple chips can be printed and processed simultaneously. Compared to current methods for the formation of microbial biofilms, namely the 96-well microtiter plate model, this fungal biofilm chip has advantages in terms of miniaturization and automation, which combine to cut reagent use and analysis time, minimize labor intensive steps, and dramatically reduce assay costs. Such a chip should accelerate the antifungal drug discovery process by enabling rapid, convenient and inexpensive screening of hundreds-to-thousands of compounds simultaneously. PMID:21544190

  18. Development of a high-throughput Candida albicans biofilm chip.

    PubMed

    Srinivasan, Anand; Uppuluri, Priya; Lopez-Ribot, Jose; Ramasubramanian, Anand K

    2011-04-22

    We have developed a high-density microarray platform consisting of nano-biofilms of Candida albicans. A robotic microarrayer was used to print yeast cells of C. albicans encapsulated in a collagen matrix at a volume as low as 50 nL onto surface-modified microscope slides. Upon incubation, the cells grow into fully formed "nano-biofilms". The morphological and architectural complexity of these biofilms were evaluated by scanning electron and confocal scanning laser microscopy. The extent of biofilm formation was determined using a microarray scanner from changes in fluorescence intensities due to FUN 1 metabolic processing. This staining technique was also adapted for antifungal susceptibility testing, which demonstrated that, similar to regular biofilms, cells within the on-chip biofilms displayed elevated levels of resistance against antifungal agents (fluconazole and amphotericin B). Thus, results from structural analyses and antifungal susceptibility testing indicated that despite miniaturization, these biofilms display the typical phenotypic properties associated with the biofilm mode of growth. In its final format, the C. albicans biofilm chip (CaBChip) is composed of 768 equivalent and spatially distinct nano-biofilms on a single slide; multiple chips can be printed and processed simultaneously. Compared to current methods for the formation of microbial biofilms, namely the 96-well microtiter plate model, this fungal biofilm chip has advantages in terms of miniaturization and automation, which combine to cut reagent use and analysis time, minimize labor intensive steps, and dramatically reduce assay costs. Such a chip should accelerate the antifungal drug discovery process by enabling rapid, convenient and inexpensive screening of hundreds-to-thousands of compounds simultaneously.

  19. [Suppression of activity of Candida albicans proteinases by cobalt chloride].

    PubMed

    Kutyreva, M P; Mukhametzianova, A R; Ulakhovich, N A

    2012-01-01

    Influence of cobalt (II) chloride on the system of Candida albicans proteinase (SAP C. alb.) (both in solution and immobilized on a surface of nitrocellulose membranes) has been investigated. In solution cobalt chloride inactivated inducible but not constitute enzyme. In the heterogenous sytem proteolitical effect of the cobalt ion on inductible proteinase was also observed.

  20. Evaluation of Candida Colonization and Specific Humoral Responses against Candida albicans in Patients with Atopic Dermatitis

    PubMed Central

    Javad, Ghaffari; Taheri Sarvtin, Mehdi; Hedayati, Mohammad Taghi; Hajheydari, Zohreh; Yazdani, Jamshid; Shokohi, Tahereh

    2015-01-01

    The aim of this study was to assess the candidal colonization and specific humoral responses against Candida albicans in patients with atopic dermatitis. One hundred patients with atopic dermatitis and 50 healthy individuals were enrolled in the study. Skin and oral specimens from all participants were cultured on CHROMagar Candida medium. Isolated yeasts were identified by using the sequence of the D1/D2 domain of the 26S rRNA gene. ELISA was used for detection of IgM, IgA, and IgG antibodies against C. albicans in sera of participants. Candida species were isolated from the skin and oral cavity of 31% of the patients and 12% of the controls. There was no significant difference between Candida colonization in patients and controls (P>0.05). Candida albicans was isolated from the skin and oral cavity of 23% of the patients and 6% of the controls (P< 0.05). There were no significant differences between serum levels of IgM and IgA in patients and controls (P>0.05). Serum level of IgG was significantly lower in patients than in controls (P<0.05). Type of Candida colonization can change in patients with atopic dermatitis. In addition, these patients have abnormalities in the production of antibodies against Candida albicans that may have a role in the pathogenesis of atopic dermatitis. PMID:25945349

  1. [Cell biology of respiration-deficient mutants of Candida albicans].

    PubMed

    Aoki, Shigeji; Ito-Kuwa, Shoko; Nakamura, Kenjirou; Nakamura, Yasunori

    2005-01-01

    Respiration-deficient (petite) mutation is caused by hereditary impairment in mitochondrial functions. Yeasts have been grouped into "petite-positive" and "petite-negative" yeasts. Candida albicans has been regarded as a member of the petite-negative yeasts in which the respiration deficiency cannot be easily induced. We have succeeded in inducing the petite mutation in C. albicans by culturing in the presence of a chemical mutagen, acriflavine, at an elevated temperature. In the present review, we describe the cell biology of C. albicans petite mutants on the basis of experiments performed by our research group: namely, on respiratory activity and cytochrome composition, fine structures of cells and mitochondria, mitochondrial DNA structure, pathogenicity, oxidative stress sensitivity, generation of reactive oxygen species (ROS) and the roles of ROS in antifungal actions. We discuss also the usefulness of petite mutants in Candida research.

  2. Two unlike cousins: Candida albicans and C. glabrata infection strategies

    PubMed Central

    Brunke, Sascha; Hube, Bernhard

    2013-01-01

    Candida albicans and C. glabrata are the two most common pathogenic yeasts of humans, yet they are phylogenetically, genetically and phenotypically very different. In this review, we compare and contrast the strategies of C. albicans and C. glabrata to attach to and invade into the host, obtain nutrients and evade the host immune response. Although their strategies share some basic concepts, they differ greatly in their outcome. While C. albicans follows an aggressive strategy to subvert the host response and to obtain nutrients for its survival, C. glabrata seems to have evolved a strategy which is based on stealth, evasion and persistence, without causing severe damage in murine models. However, both fungi are successful as commensals and as pathogens of humans. Understanding these strategies will help in finding novel ways to fight Candida, and fungal infections in general. PMID:23253282

  3. Host response to Candida albicans bloodstream infection and sepsis

    PubMed Central

    Duggan, Seána; Leonhardt, Ines; Hünniger, Kerstin; Kurzai, Oliver

    2015-01-01

    Candida albicans is a major cause of bloodstream infection which may present as sepsis and septic shock - major causes of morbidity and mortality world-wide. After invasion of the pathogen, innate mechanisms govern the early response. Here, we outline the models used to study these mechanisms and summarize our current understanding of innate immune responses during Candida bloodstream infection. This includes protective immunity as well as harmful responses resulting in Candida induced sepsis. Neutrophilic granulocytes are considered principal effector cells conferring protection and recognize C. albicans mainly via complement receptor 3. They possess a range of effector mechanisms, contributing to elimination of the pathogen. Neutrophil activation is closely linked to complement and modulated by activated mononuclear cells. A thorough understanding of these mechanisms will help in creating an individualized approach to patients suffering from systemic candidiasis and aid in optimizing clinical management. PMID:25785541

  4. Candida albicans: genotyping methods and clade related phenotypic characteristics

    PubMed Central

    Lyon, Juliana P.; Moraes, Karen C.M.; Moreira, Leonardo M.; Aimbire, Flávio; de Resende, Maria Aparecida

    2010-01-01

    Several molecular methods, such as Southern blotting hybridization, Multilocus Sequence Typing, and DNA microsatellite analysis, have been employed to genotype Candida albicans. The genotype analysis allows to group strains in clades, that is, a group composed of one ancestor and its descendants. These genotype studies demonstrate that clades distribution is influenced by geographic area as well as that antifungal resistance is associated with particular clades. These findings suggested that C. albicans reproduces mainly in a clonal manner, with certain degree of DNA microevolution. Additionally, virulence factors and site of isolation have also been associated with clade specificity. The present article is a brief review about the methods used for Candida genotyping and the correlated clade systems established. Special emphasis is given to Ca3 hybridization, MLST, and Microsatellites. The present work is also focused on the phenotypic and physiological traits associated with Candida clades. PMID:24031564

  5. Chemical composition and antifungal activity of Satureja hortensis L. essentiall oil against planktonic and biofilm growth of Candida albicans isolates from buccal lesions of HIV(+) individuals.

    PubMed

    Sharifzadeh, Aghil; Khosravi, Ali Reza; Ahmadian, Shahin

    2016-07-01

    Oral candidiasis is an opportunistic infection of the oral cavity which usually occurs in the immunocompromised individuals. Candida albicans (C. albicans) is the most common species of yeast responsible for oral candidiasis. This study investigated the effects of Satureja hortensis L. essentiall oil (EO) on the planktonic, biofilm formation and mature biofilms of C. albicans isolates from buccal lesions of HIV(+) individuals. MTT reduction assay, broth micro-dilution method and scanning electron microscopy (SEM) were employed to determine the effect of mentioned EO on the C. albicans planktonic and biofilm forms. GC-GC/MS was used to detect the major active compounds of EO. Thymol (45.9%), gamma-terpinen (16.71%), carvacrol (12.81%) and p-cymene (9.61%) were found as the most abundant constituents. MIC values ranged from 250 to 400 μg/ml and MFC values ranged from 350 to 500 μg/ml. All C. albicans isolates formed biofilm on polystyrene plats but the quantity of biofilm mass (optical density) was different for the isolates ranging from 0.850 to 0.559 nm. The mean of biofilm formation by C. albicans isolates was reduced by 87.1 ± 3.7%, 73.6 ± 5.1%, 69.4 ± 5.3% and 67 ± 4.2% at 4800, 3200, 2400 and 1600 μg/ml, respectively. In sub-MIC concentration, SEM analysis revealed loosening of cells, deformity of three dimensional structures of biofilms and shrinkage in cell membranes of sessile cells. In conclusion, the substantial anti-fungal activity showed by S. hortensis L. EO suggests exploitation of this oil as potential natural anti-biofilm product to deal with the problem of buccal cavity lesion associated with C. albicans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Differentiation of Candida albicans, Candida glabrata, and Candida krusei by FT-IR and chemometrics by CHROMagar™ Candida.

    PubMed

    Wohlmeister, Denise; Vianna, Débora Renz Barreto; Helfer, Virginia Etges; Calil, Luciane Noal; Buffon, Andréia; Fuentefria, Alexandre Meneghello; Corbellini, Valeriano Antonio; Pilger, Diogo André

    2017-10-01

    Pathogenic Candida species are detected in clinical infections. CHROMagar™ is a phenotypical method used to identify Candida species, although it has limitations, which indicates the need for more sensitive and specific techniques. Infrared Spectroscopy (FT-IR) is an analytical vibrational technique used to identify patterns of metabolic fingerprint of biological matrixes, particularly whole microbial cell systems as Candida sp. in association of classificatory chemometrics algorithms. On the other hand, Soft Independent Modeling by Class Analogy (SIMCA) is one of the typical algorithms still little employed in microbiological classification. This study demonstrates the applicability of the FT-IR-technique by specular reflectance associated with SIMCA to discriminate Candida species isolated from vaginal discharges and grown on CHROMagar™. The differences in spectra of C. albicans, C. glabrata and C. krusei were suitable for use in the discrimination of these species, which was observed by PCA. Then, a SIMCA model was constructed with standard samples of three species and using the spectral region of 1792-1561cm(-1). All samples (n=48) were properly classified based on the chromogenic method using CHROMagar™ Candida. In total, 93.4% (n=45) of the samples were correctly and unambiguously classified (Class I). Two samples of C. albicans were classified correctly, though these could have been C. glabrata (Class II). Also, one C. glabrata sample could have been classified as C. krusei (Class II). Concerning these three samples, one triplicate of each was included in Class II and two in Class I. Therefore, FT-IR associated with SIMCA can be used to identify samples of C. albicans, C. glabrata, and C. krusei grown in CHROMagar™ Candida aiming to improve clinical applications of this technique. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Baicalin prevents Candida albicans infections via increasing its apoptosis rate

    SciTech Connect

    Yang, Shulong; Fu, Yingyuan Wu, Xiuzhen; Zhou, Zhixing; Xu, Jing; Zeng, Xiaoping; Kuang, Nanzhen; Zeng, Yurong

    2014-08-15

    Highlights: • Baicalin increases the ratio of the G0/G1 stages and C. albicans apoptosis. • Baicalin decreases the proliferation index of C. albicans. • Baicalin inhibits the biosynthesis of DNA, RNA and protein in C. albicans. • Baicalin depresses Succinate Dehydrogenase and Ca{sup 2+}–Mg{sup 2+} ATPase in C. albicans. • Baicalin increases the endocytic free Ca{sup 2+} concentration in C. albicans. - Abstract: Background: These experiments were employed to explore the mechanisms underlying baicalin action on Candida albicans. Methodology and principal findings: We detected the baicalin inhibition effects on three isotope-labeled precursors of {sup 3}H-UdR, {sup 3}H-TdR and {sup 3}H-leucine incorporation into C. albicans using the isotope incorporation technology. The activities of Succinate Dehydrogenase (SDH), cytochrome oxidase (CCO) and Ca{sup 2+}–Mg{sup 2+} ATPase, cytosolic Ca{sup 2+} concentration, the cell cycle and apoptosis, as well as the ultrastructure of C.albicans were also tested. We found that baicalin inhibited {sup 3}H-UdR, {sup 3}H-TdR and {sup 3}H-leucine incorporation into C.albicans (P < 0.005). The activities of the SDH and Ca{sup 2+}–Mg{sup 2+} ATPase of C.albicans in baicalin groups were lower than those in control group (P < 0.05). Ca{sup 2+} concentrations of C. albicans in baicalin groups were much higher than those in control group (P < 0.05). The ratio of C.albicans at the G0/G1 stage increased in baicalin groups in dose dependent manner (P < 0.01). There were a significant differences in the apoptosis rate of C.albicans between baicalin and control groups (P < 0.01). After 12–48 h incubation with baicalin (1 mg/ml), C. albicans shown to be markedly damaged under transmission electron micrographs. Innovation and significance: Baicalin can increase the apoptosis rate of C. albicans. These effects of Baicalin may involved in its inhibiting the activities of the SDH and Ca{sup 2+}–Mg{sup 2+} ATPase, increasing

  8. Prevalence of candida albicans in dental plaque and caries lesion of early childhood caries (ECC) according to sampling site

    PubMed Central

    Ghasempour, Maryam; Sefidgar, Seyed Ali Asghar; Eyzadian, Haniyeh; Gharakhani, Samaneh

    2011-01-01

    Background: Candida albicans may have cariogenic potential but its role in caries etiology has not been established. The aim of this study was to determine candida albicans in supragingival dental plaque and infected dentine of cervical and proximal in early childhood caries (ECC). Methods: This cross-sectional study was carried out on 6o children aged 2-5 years, which were divided into 3 groups: children with at least one cervical caries; children with at least one proximal caries and caries-free. The infected dentine was collected from cervical and proximal caries lesions and plaque samples were collected from the three groups in order to compare the frequency of candida albicans in the collected sites. All samples were cultured in Sabouraud and CHROMagar medium and the cases that were positive for candida albicans were cultured in germ tube. Data were collected and analyzed. Results: The mean age of the children was 3.9 years. From 100 samples, candida albicans samples were isolated in 55%, mold fungi were found in 29% cases and there was no fungal growth in 16% of the samples. In plaque samples, candida albicans were found in 15% of caries-free samples, 20% of the proximal and 80% of the cervical caries. In samples extracted from the caries, candida albicans were found in 60% of the proximal and 100% of the cervical caries. Mothers with university educational level had children with more cervical decays, caries free and proximal caries, respectively. Conclusion: The results showed that prevalence of Candida albicans in dental plaque and caries lesions of children with early childhood caries were relatively high and the prevalence was higher in cervical caries group. PMID:24551436

  9. Yeasts isolated from Algerian infants's feces revealed a burden of Candida albicans species, non-albicans Candida species and Saccharomyces cerevisiae.

    PubMed

    Seddik, Hamza Ait; Ceugniez, Alexandre; Bendali, Farida; Cudennec, Benoit; Drider, Djamel

    2016-01-01

    This study aimed at showing the yeast diversity in feces of Algerian infants, aged between 1 and 24 months, hospitalized at Bejaia hospital (northeast side of the country). Thus, 20 colonies with yeast characteristics were isolated and identified using biochemical (ID32C Api system) and molecular (sequencing of ITS1-5.8S-ITS2 region) methods. Almost all colonies isolated (19 strains) were identified as Candida spp., with predominance of Candida albicans species, and one strain was identified as Saccharomyces cerevisiae. Screening of strains with inhibitory activities unveiled the potential of Candida parapsilosis P48L1 and Candida albicans P51L1 to inhibit the growth of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Further studies performed with these two Candida strains revealed their susceptibility to clinically used antifungal compounds and were then characterized for their cytotoxicity and hemolytic properties. On the other hand, Saccharomyces cerevisiae P9L1 isolated as well in this study was shown to be devoid of antagonism but resulted safe and overall usable as probiotic.

  10. Postantifungal Effect of Micafungin against the Species Complexes of Candida albicans and Candida parapsilosis.

    PubMed

    Gil-Alonso, Sandra; Jauregizar, Nerea; Eraso, Elena; Quindós, Guillermo

    2015-01-01

    Micafungin is an effective antifungal agent useful for the therapy of invasive candidiasis. Candida albicans is the most common cause of invasive candidiasis; however, infections due to non-C. albicans species, such as Candida parapsilosis, are rising. Killing and postantifungal effects (PAFE) are important factors in both dose interval choice and infection outcome. The aim of this study was to determinate the micafungin PAFE against 7 C. albicans strains, 5 Candida dubliniensis, 2 Candida Africana, 3 C. parapsilosis, 2 Candida metapsilosis and 2 Candida orthopsilosis. For PAFE studies, cells were exposed to micafungin for 1 h at concentrations ranging from 0.12 to 8 μg/ml. Time-kill experiments (TK) were conducted at the same concentrations. Samples were removed at each time point (0-48 h) and viable counts determined. Micafungin (2 μg/ml) was fungicidal (≥ 3 log10 reduction) in TK against 5 out of 14 (36%) strains of C. albicans complex. In PAFE experiments, fungicidal endpoint was achieved against 2 out of 14 strains (14%). In TK against C. parapsilosis, 8 μg/ml of micafungin turned out to be fungicidal against 4 out 7 (57%) strains. Conversely, fungicidal endpoint was not achieved in PAFE studies. PAFE results for C. albicans complex (41.83 ± 2.18 h) differed from C. parapsilosis complex (8.07 ± 4.2 h) at the highest tested concentration of micafungin. In conclusion, micafungin showed significant differences in PAFE against C. albicans and C. parapsilosis complexes, being PAFE for the C. albicans complex longer than for the C. parapsilosis complex.

  11. Postantifungal Effect of Micafungin against the Species Complexes of Candida albicans and Candida parapsilosis

    PubMed Central

    Gil-Alonso, Sandra; Jauregizar, Nerea; Eraso, Elena; Quindós, Guillermo

    2015-01-01

    Micafungin is an effective antifungal agent useful for the therapy of invasive candidiasis. Candida albicans is the most common cause of invasive candidiasis; however, infections due to non-C. albicans species, such as Candida parapsilosis, are rising. Killing and postantifungal effects (PAFE) are important factors in both dose interval choice and infection outcome. The aim of this study was to determinate the micafungin PAFE against 7 C. albicans strains, 5 Candida dubliniensis, 2 Candida Africana, 3 C. parapsilosis, 2 Candida metapsilosis and 2 Candida orthopsilosis. For PAFE studies, cells were exposed to micafungin for 1 h at concentrations ranging from 0.12 to 8 μg/ml. Time-kill experiments (TK) were conducted at the same concentrations. Samples were removed at each time point (0-48 h) and viable counts determined. Micafungin (2 μg/ml) was fungicidal (≥ 3 log10 reduction) in TK against 5 out of 14 (36%) strains of C. albicans complex. In PAFE experiments, fungicidal endpoint was achieved against 2 out of 14 strains (14%). In TK against C. parapsilosis, 8 μg/ml of micafungin turned out to be fungicidal against 4 out 7 (57%) strains. Conversely, fungicidal endpoint was not achieved in PAFE studies. PAFE results for C. albicans complex (41.83 ± 2.18 h) differed from C. parapsilosis complex (8.07 ± 4.2 h) at the highest tested concentration of micafungin. In conclusion, micafungin showed significant differences in PAFE against C. albicans and C. parapsilosis complexes, being PAFE for the C. albicans complex longer than for the C. parapsilosis complex. PMID:26168269

  12. The Fungus Candida albicans Tolerates Ambiguity at Multiple Codons.

    PubMed

    Simões, João; Bezerra, Ana R; Moura, Gabriela R; Araújo, Hugo; Gut, Ivo; Bayes, Mónica; Santos, Manuel A S

    2016-01-01

    The ascomycete Candida albicans is a normal resident of the gastrointestinal tract of humans and other warm-blooded animals. It occurs in a broad range of body sites and has high capacity to survive and proliferate in adverse environments with drastic changes in oxygen, carbon dioxide, pH, osmolarity, nutrients, and temperature. Its biology is unique due to flexible reassignment of the leucine CUG codon to serine and synthesis of statistical proteins. Under standard growth conditions, CUG sites incorporate leucine (3% of the times) and serine (97% of the times) on a proteome wide scale, but leucine incorporation fluctuates in response to environmental stressors and can be artificially increased up to 98%. In order to determine whether such flexibility also exists at other codons, we have constructed several serine tRNAs that decode various non-cognate codons. Expression of these tRNAs had minor effects on fitness, but growth of the mistranslating strains at different temperatures, in medium with different pH and nutrients composition was often enhanced relatively to the wild type (WT) strain, supporting our previous data on adaptive roles of CUG ambiguity in variable growth conditions. Parallel evolution of the recombinant strains (100 generations) followed by full genome resequencing identified various strain specific single nucleotide polymorphisms (SNP) and one SNP in the deneddylase (JAB1) gene in all strains. Since JAB1 is a subunit of the COP9 signalosome complex, which interacts with cullin (Cdc53p) to mediate degradation of a variety of cellular proteins, our data suggest that neddylation plays a key role in tolerance and adaptation to codon ambiguity in C. albicans.

  13. The Fungus Candida albicans Tolerates Ambiguity at Multiple Codons

    PubMed Central

    Simões, João; Bezerra, Ana R.; Moura, Gabriela R.; Araújo, Hugo; Gut, Ivo; Bayes, Mónica; Santos, Manuel A. S.

    2016-01-01

    The ascomycete Candida albicans is a normal resident of the gastrointestinal tract of humans and other warm-blooded animals. It occurs in a broad range of body sites and has high capacity to survive and proliferate in adverse environments with drastic changes in oxygen, carbon dioxide, pH, osmolarity, nutrients, and temperature. Its biology is unique due to flexible reassignment of the leucine CUG codon to serine and synthesis of statistical proteins. Under standard growth conditions, CUG sites incorporate leucine (3% of the times) and serine (97% of the times) on a proteome wide scale, but leucine incorporation fluctuates in response to environmental stressors and can be artificially increased up to 98%. In order to determine whether such flexibility also exists at other codons, we have constructed several serine tRNAs that decode various non-cognate codons. Expression of these tRNAs had minor effects on fitness, but growth of the mistranslating strains at different temperatures, in medium with different pH and nutrients composition was often enhanced relatively to the wild type (WT) strain, supporting our previous data on adaptive roles of CUG ambiguity in variable growth conditions. Parallel evolution of the recombinant strains (100 generations) followed by full genome resequencing identified various strain specific single nucleotide polymorphisms (SNP) and one SNP in the deneddylase (JAB1) gene in all strains. Since JAB1 is a subunit of the COP9 signalosome complex, which interacts with cullin (Cdc53p) to mediate degradation of a variety of cellular proteins, our data suggest that neddylation plays a key role in tolerance and adaptation to codon ambiguity in C. albicans. PMID:27065968

  14. Murine model of concurrent oral and vaginal Candida albicans colonisation.

    PubMed

    Rahman, Durdana; Mistry, Mukesh; Thavaraj, Selvam; Naglik, Julian R; Challacombe, Stephen J

    2012-01-01

    Investigations into the complex interaction between the fungal pathogen Candida albicans and its human host require the use of animals as in vivo models. A major advance is the creation of a low-oestrogen murine model of concurrent oral and vaginal C. albicans colonisation that resembles human candidal carriage at both mucosal sites. Weekly intramuscular (5 μg) and subcutaneous (5 μg) oestrogen administration was determined as optimal, enhancing oral colonisation but essential for vaginal colonisation. Using a clinical C. albicans oral isolate, persistent colonisation for up to 6 weeks can be achieved at both sites in two strains of mice (BALB/c and C57BL/6). This concurrent model of mucosal colonisation reduces the numbers of experimental mice by half, and opens up new avenues of research in assessing potential mucosal vaccine candidates and in studying delicate host-pathogen interactions during the most natural state of C. albicans epithelial colonisation.

  15. Inhibition of Candida albicans virulence factors by novel levofloxacin derivatives.

    PubMed

    Shafreen, Raja Mohamed Beema; Raja Mohamed, Beema Shafreen; Muthamil, Subramanian; Subramanian, Muthamil; Pandian, Shunmugiah Karutha; Shunmugiah, Karutha Pandian

    2014-08-01

    Candida albicans is an important opportunistic fungal pathogen, responsible for biofilm associated infections in immunocompromised patients. The aim of the present study was to investigate the antibiofilm properties of novel levofloxacin derivatives on C. albicans biofilms. The levofloxacin derivatives at their Biofilm Inhibitory Concentrations (BIC) were able to inhibit the biofilms of C. albicans, the yeast-to-hyphal transition and were also able to disrupt their mature biofilms. Furthermore, Real-time PCR analysis showed that the expression of ergosterol biosynthesis pathway gene (ERG11) and the efflux pump-encoding genes (CDR1 and MDR1) was decreased upon treatment with the levofloxacin derivatives. The total ergosterol content quantified using UV spectrophotomer showed decrease in ergosterol in the presence of levofloxacin derivatives. Overall, levofloxacin derivatives (6a, 6c and 7d) are capable of inhibiting C. albicans virulence factors. Therefore, these compounds with potential therapeutic implications can be used as new strategy to treat biofilm-related candidal infections.

  16. Molecular genetic techniques for gene manipulation in Candida albicans

    PubMed Central

    Xu, Qiu-Rong; Yan, Lan; Lv, Quan-Zhen; Zhou, Mi; Sui, Xue; Cao, Yong-Bing; Jiang, Yuan-Ying

    2014-01-01

    Candida albicans is one of the most common fungal pathogen in humans due to its high frequency as an opportunistic and pathogenic fungus causing superficial as well as invasive infections in immunocompromised patients. An understanding of gene function in C. albicans is necessary to study the molecular basis of its pathogenesis, virulence and drug resistance. Several manipulation techniques have been used for investigation of gene function in C. albicans, including gene disruption, controlled gene expression, protein tagging, gene reintegration, and overexpression. In this review, the main cassettes containing selectable markers used for gene manipulation in C. albicans are summarized; the advantages and limitations of these cassettes are discussed concerning the influences on the target gene expression and the virulence of the mutant strains. PMID:24759671

  17. Short peptides allowing preferential detection of Candida albicans hyphae.

    PubMed

    Kaba, Hani E J; Pölderl, Antonia; Bilitewski, Ursula

    2015-09-01

    Whereas the detection of pathogens via recognition of surface structures by specific antibodies and various types of antibody mimics is frequently described, the applicability of short linear peptides as sensor molecules or diagnostic tools is less well-known. We selected peptides which were previously reported to bind to recombinant S. cerevisiae cells, expressing members of the C. albicans Agglutinin-Like-Sequence (ALS) cell wall protein family. We slightly modified amino acid sequences to evaluate peptide sequence properties influencing binding to C. albicans cells. Among the selected peptides, decamer peptides with an "AP"-N-terminus were superior to shorter peptides. The new decamer peptide FBP4 stained viable C. albicans cells more efficiently in their mature hyphal form than in their yeast form. Moreover, it allowed distinction of C. albicans from other related Candida spp. and could thus be the basis for the development of a useful tool for the diagnosis of invasive candidiasis.

  18. Inhibition of Candida albicans yeast-hyphal transition and biofilm formation by Solidago virgaurea water extracts.

    PubMed

    Chevalier, Marlène; Medioni, Etienne; Prêcheur, Isabelle

    2012-07-01

    Xerostomia is a decrease of saliva secretion, which can unbalance the oral microflora, mainly to the benefit of Candida albicans. The aim of the present study was to find a plant extract that could create an unfavourable environment for Candida, and would, therefore, be appropriate for use in a dry-mouth daily-care mouthwash. Water extract from the herbaceous plant Solidago virgaurea (Goldenrod) was selected due to its saponin content (plant detergents). Saponin concentrations reached 0.7 and 0.95 mg ml(-1) in S. virgaurea subsp. virgaurea and S. virgaurea subsp. alpestris extracts, respectively. C. albicans was grown in liquid medium and cells were counted by microscopic examination after 0, 4 and 24 h of incubation. Solidago extracts did not inhibit the growth of C. albicans (four strains), Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus mutans, Streptococcus salivarius or Enterococcus faecalis. When inocula were incubated with Solidago extract for 4 and 24 h, we observed a decrease in Candida yeast-hyphal transition. Candida biofilms were then prepared in microtitre plates and treated with plant extracts at 0 h, to estimate biofilm formation, or at 18 h to estimate the effect of the saponin on pre-formed biofilms. Biofilm formation and pre-formed biofilms were both strongly inhibited. In conclusion, the S. virgaurea extract was efficient against two key virulence factors of C. albicans: the yeast-hyphal transition phase and biofilm formation.

  19. Rat Indwelling Urinary Catheter Model of Candida albicans Biofilm Infection

    PubMed Central

    Nett, Jeniel E.; Brooks, Erin G.; Cabezas-Olcoz, Jonathan; Sanchez, Hiram; Zarnowski, Robert; Marchillo, Karen

    2014-01-01

    Indwelling urinary catheters are commonly used in the management of hospitalized patients. Candida can adhere to the device surface and propagate as a biofilm. These Candida biofilm communities differ from free-floating Candida, exhibiting high tolerance to antifungal therapy. The significance of catheter-associated candiduria is often unclear, and treatment may be problematic considering the biofilm drug-resistant phenotype. Here we describe a rodent model for the study of urinary catheter-associated Candida albicans biofilm infection that mimics this common process in patients. In the setting of a functioning, indwelling urinary catheter in a rat, Candida proliferated as a biofilm on the device surface. Characteristic biofilm architecture was observed, including adherent, filamentous cells embedded in an extracellular matrix. Similar to what occurs in human patients, animals with this infection developed candiduria and pyuria. Infection progressed to cystitis, and a biofilmlike covering was observed over the bladder surface. Furthermore, large numbers of C. albicans cells were dispersed into the urine from either the catheter or bladder wall biofilm over the infection period. We successfully utilized the model to test the efficacy of antifungals, analyze transcriptional patterns, and examine the phenotype of a genetic mutant. The model should be useful for future investigations involving the pathogenesis, diagnosis, therapy, prevention, and drug resistance of Candida biofilms in the urinary tract. PMID:25183731

  20. Sensitivity of Candida albicans to essential oils: are they an alternative to antifungal agents?

    PubMed

    Bona, E; Cantamessa, S; Pavan, M; Novello, G; Massa, N; Rocchetti, A; Berta, G; Gamalero, E

    2016-12-01

    Candida albicans is an important opportunistic pathogen, responsible for the majority of yeast infections in humans. Essential oils, extracted from aromatic plants, are well-known antimicrobial agents, characterized by a broad spectrum of activities, including antifungal properties. The aim of this work was to assess the sensitivity of 30 different vaginal isolated strains of C. albicans to 12 essential oils, compared to the three main used drugs (clotrimazole, fluconazole and itraconazole). Thirty strains of C. albicans were isolated from vaginal swab on CHROMagar(™) Candida. The agar disc diffusion method was employed to determine the sensitivity to the essential oils. The antifungal activity of the essential oils and antifungal drugs (clotrimazole, itraconazole and fluconazole) were investigated using a microdilution method. Transmission and scanning electron microscopy analyses were performed to get a deep inside on cellular damages. Mint, basil, lavender, tea tree oil, winter savory and oregano essential oils inhibited both the growth and the activity of C. albicans more efficiently than clotrimazole. Damages induced by essential oils at the cellular level were stronger than those caused by clotrimazole. Candida albicans is more sensitive to different essential oils compared to the main used drugs. Moreover, the essential oil affected mainly the cell wall and the membranes of the yeast. The results of this work support the research for new alternatives or complementary therapies against vaginal candidiasis. © 2016 The Society for Applied Microbiology.

  1. Bacterial GtfB Augments Candida albicans Accumulation in Cross-Kingdom Biofilms.

    PubMed

    Ellepola, K; Liu, Y; Cao, T; Koo, H; Seneviratne, C J

    2017-09-01

    Streptococcus mutans is a biofilm-forming oral pathogen commonly associated with dental caries. Clinical studies have shown that S. mutans is often detected with Candida albicans in early childhood caries. Although the C. albicans presence has been shown to enhance bacterial accumulation in biofilms, the influence of S. mutans on fungal biology in this mixed-species relationship remains largely uncharacterized. Therefore, we aimed to investigate how the presence of S. mutans influences C. albicans biofilm development and coexistence. Using a newly established haploid biofilm model of C. albicans, we found that S. mutans augmented haploid C. albicans accumulation in mixed-species biofilms. Similarly, diploid C. albicans also showed enhanced biofilm formation in the presence of S. mutans. Surprisingly, the presence of S. mutans restored the biofilm-forming ability of C. albicans bcr1Δ mutant and bcr1Δ/Δ mutant, which is known to be severely defective in biofilm formation when grown as single species. Moreover, C. albicans hyphal growth factor HWP1 as well as ALS1 and ALS3, which are also involved in fungal biofilm formation, were upregulated in the presence of S. mutans. Subsequently, we found that S. mutans-derived glucosyltransferase B (GtfB) itself can promote C. albicans biofilm development. Interestingly, GtfB was able to increase the expression of HWP1, ALS1, and ALS3 genes in the C. albicans diploid wild-type SC5314 and bcr1Δ/Δ, leading to enhanced fungal biofilms. Hence, the present study demonstrates that a bacterial exoenzyme (GtfB) augments the C. albicans counterpart in mixed-species biofilms through a BCR1-independent mechanism. This novel finding may explain the mutualistic role of S. mutans and C. albicans in cariogenic biofilms.

  2. Defining pheromone-receptor signaling in Candida albicans and related asexual Candida species.

    PubMed

    Lin, Ching-Hsuan; Choi, Anthony; Bennett, Richard J

    2011-12-01

    Candida albicans is an important human fungal pathogen in which sexual reproduction is under the control of the novel white-opaque switch. Opaque cells are the mating-competent form, whereas white cells do not mate but can still respond to pheromones, resulting in biofilm formation. In this study, we first define the domains of the α-pheromone receptor Ste2 that are necessary for signaling in both white and opaque forms. Both cell states require the IC loop 3 (IC3) and the C-terminal tail of Ste2 for the cellular response, whereas the first IC loop (IC1) of Ste2 is dispensable for signaling. To also address pheromone-receptor interactions in related species, including apparently asexual Candida species, Ste2 orthologues were heterologously expressed in Candida albicans. Ste2 receptors from multiple Candida clade species were functional when expressed in C. albicans, whereas the Ste2 receptor of Candida lusitaniae was nonfunctional. Significantly, however, expression of a chimeric C. lusitaniae Ste2 receptor containing the C-terminal tail of Ste2 from C. albicans generated a productive response to C. lusitaniae pheromone. This system has allowed us to characterize pheromones from multiple Candida species and indicates that functional pheromone-receptor couples exist in fungal species that have yet to be shown to undergo sexual mating.

  3. Candida albicans biofilm development under increased temperature.

    PubMed

    Pumeesat, Potjaman; Muangkaew, Watcharamat; Ampawong, Sumate; Luplertlop, Natthanej

    2017-08-21

    C. albicans is one of the most important species of fungi known to produce biofilms on installed medical devices. The environment surrounding the fungi influences the development of the biofilm. Temperature is known to affect the yeast-to-hypha transition of C. albicans, but the impact of this factor on biofilm formation is still not understood. This study aimed to investigate the effects of temperature (42 °C versus 37 °C) on the formation of C. albicans biofilms. Three reference C. albicans strains were used: SC 5314, ATCC 90028, and ATCC 96901. Biofilm development was monitored in a series of time intervals, 2, 4, 6, 8, 24, and 48 h, at both 37 °C and 42 °C. Biofilm formation under each condition was evaluated by scanning electron microscopy, crystal violet staining, and 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-(phenylamino)-carbonyl-2H-tetrazoliumhydroxide reduction assay. Our results demonstrated that at 42 °C, tested strains of C. albicans could produce a biofilm, but the mass, thickness, and metabolic activity were lower than those of the biofilm formed at 37 °C.

  4. Photoinactivation of single and mixed biofilms of Candida albicans and non-albicans Candida species using Phorodithazine(®).

    PubMed

    Carmello, Juliana Cabrini; Alves, Fernanda; Mima, Ewerton Garcia de Oliveira; Jorge, Janaina Habib; Bagnato, Vanderlei Salvador; Pavarina, Ana Cláudia

    2017-03-01

    This study evaluated the effectiveness of antimicrobial photodynamic therapy (aPDT) mediated by Photodithazine(®) (PDZ) formulated in hydrogel, in the inactivation of mono and duo-species biofilms of Candida albicans, Candida glabrata and Candida tropicalis. Standardized suspensions of each strain were prepared and after biofilm formation, mono-species were treated with 150 and 175mg/L of PDZ for 20min (pre-irradiation time), and exposed to LED light at a dose of 37.5J/cm(2) (660nm). The duo-species biofilms (C. albicans+C. glabrata and C. albicans+C. tropicalis) were treated with 150mg/L of PDZ and light. Additional samples were treated with PDZ or light only, and the control did not receive any treatment. Next, microbiological evaluation was performed by spreading the cells on Sabouraud Dextrose Agar and CHROMagar Candida for colony forming units (CFU/mL). Moreover, the total biomass of biofilm was verified using the crystal violet staining assay (CV). The data were submitted to ANOVA and Tukey post-hoc (α=0.05). The use of PDZ 150mg/L promoted a reduction of 1.0, 1.2, 1.5 log10 in the viability of C. glabrata, C. albicans and C. tropicalis, respectively. The same concentration reduced in 1.0 log10 the viability of each species grown as duo-species biofilms. The crystal violet assay showed that the use of 150mg/L reduced 24.4%, 39.2% and 43.7% of the total biomass of C. albicans, C. tropicalis and C. glabrata, respectively. aPDT did not reduce the total biomass to the duo-species biofilms. Thus, PDZ-mediated aPDT was more effective in the inactivation of mono-species biofilms of Candida spp. compared with duo-species biofilm.

  5. Prevalence of Candida albicans, Candida dubliniensis and Candida africana in pregnant women suffering from vulvovaginal candidiasis in Argentina.

    PubMed

    Mucci, María Josefina; Cuestas, María Luján; Landanburu, María Fernanda; Mujica, María Teresa

    Vulvovaginal candidiasis (VVC) is a vulvovaginitis commonly diagnosed in gynecology care. In recent years, the taxonomy of the most important pathogenic Candida species, such as Candida albicans have undergone significant changes. This study examined the prevalence of C. albicans, Candida africana, and Candida dubliniensis in vaginal specimens from 210 pregnant women suffering from vulvovaginitis or having asymptomatic colonization. Phenotypic and molecular methods were used for the identification of the species. During the studied period, 55 isolates of Candida or other yeasts were obtained from specimens collected from 52 patients suffering from vulvovaginitis (24.8%). C. albicans was the predominant Candida species in 42 isolates (80.7%), either alone or in combination with other species of the genus (5.7%, n=3). Additionally, nine isolates of C. albicans (50%) were obtained from asymptomatic patients (n=18). C. dubliniensis was the causative agent in 2 (3.8%) cases of VVC, and was also isolated in one asymptomatic patient. Molecular assays were carried out using specific PCR to amplify the ACT1-associated intron sequence of C. dubliniensis. The amplification of the HWP1 gene also correctly identified isolates of the species C. albicans and C. dubliniensis. No C. africana was isolated in this work. Some C. albicans isolates were either homozygous or heterozygous at the HWP1 locus. The distribution of heterozygous and homozygous C. albicans isolates at the HWP1 locus was very similar among patients suffering from VVC and asymptomatic patients (p=0.897). The presence of C. albicans and C. dubliniensis, and the absence of C. africana in pregnant is noteworthy. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Survival of Candida albicans in tropical marine and fresh waters.

    PubMed Central

    Valdes-Collazo, L; Schultz, A J; Hazen, T C

    1987-01-01

    A survey of Candida albicans indicated that the organism was present at all sites sampled in a rain forest stream and in near-shore coastal waters of Puerto Rico. In the rain forest watershed no relationship existed between densities of fecal coliforms and densities of C. albicans. At two pristine sites in the rain forest watershed both C. albicans and Escherichia coli survived in diffusion chambers for extended periods of time. In near-shore coastal waters C. albicans and E. coli survival times in diffusion chambers were enhanced by effluent from a rum distillery. The rum distillery effluent had a greater effect on E. coli than on C. albicans survival in the diffusion chambers. These studies show that neither E. coli nor C. albicans organisms are good indicators of recent fecal contamination in tropical waters. It further demonstrates that pristine freshwater environments and marine waters receiving organic loading in the tropics can support densities of C. albicans which may be a health hazard. Images PMID:3310885

  7. Comparison of the hemolytic activity between C. albicans and non-albicans Candida species.

    PubMed

    Rossoni, Rodnei Dennis; Barbosa, Júnia Oliveira; Vilela, Simone Furgeri Godinho; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos

    2013-01-01

    The ability to produce enzymes, such as hemolysins, is an important virulence factor for the genus Candida.The objective of this study was to compare the hemolytic activity between C. albicansand non-albicans Candida species. Fifty strains of Candida species, isolated from the oral cavity of patients infected with HIV were studied. The isolates included the following species: C. albicans, C. dubliniensis, C. glabrata, C. tropicalis, C. krusei, C. parapsilosis, C. dubliniensis, C. norvegensis, C. lusitaniae, and C. guilliermondii. Hemolysin production was evaluated on Sabouraud dextrose agar containing chloramphenicol, blood, and glucose. A loop-full of pure Candidaculture was spot-inoculated onto plates and incubated at 37 ºC for 24 h in a 5% CO2 atmosphere. Hemolytic activity was defined as the formation of a translucent halo around the colonies. All C. albicansstrains that were studied produced hemolysins. Among the non-albicans Candidaspecies, 86% exhibited hemolytic activity. Only C. guilliermondiiand some C. parapsilosis isolates were negative for this enzyme. In conclusion, most non-albicans Candidaspecies had a similar ability to produce hemolysins when compared to C. albicans.

  8. The Regulatory Subunit of Protein Kinase A (Bcy1) in Candida albicans Plays Critical Roles in Filamentation and White-Opaque Switching but Is Not Essential for Cell Growth

    PubMed Central

    Ding, Xuefen; Cao, Chengjun; Zheng, Qiushi; Huang, Guanghua

    2017-01-01

    The conserved cAMP-dependent protein kinase (PKA) is composed of the regulatory and catalytic subunits and acts as the central component of the cAMP signaling pathway. In the human fungal pathogen Candida albicans, the PKA regulatory subunit Bcy1 plays a critical role in the regulation of cell differentiation and death. It has long been considered that Bcy1 is essential for cell viability in C. albicans. In the current study, surprisingly, we found that Bcy1 is not required for cell growth, and we successfully generated a bcy1/bcy1 null mutant in C. albicans. Deletion of BCY1 leads to multiple cellular morphologies and promotes the development of filaments. Filamentous and smooth colonies are two typical morphological types of the bcy1/bcy1 mutant, which can undergo spontaneous switching between the two types. Cells of filamentous colonies grow better on a number of different culture media and have a higher survival rate than cells of smooth colonies. In addition, deletion of BCY1 significantly increased the frequency of white-to-opaque switching on N-acetylglucosamine (GlcNAc)-containing medium. The bcy1/bcy1 null mutant generated herein provides the field a new resource to study the biological functions of the cAMP signaling pathway in C. albicans. PMID:28105026

  9. The Regulatory Subunit of Protein Kinase A (Bcy1) in Candida albicans Plays Critical Roles in Filamentation and White-Opaque Switching but Is Not Essential for Cell Growth.

    PubMed

    Ding, Xuefen; Cao, Chengjun; Zheng, Qiushi; Huang, Guanghua

    2016-01-01

    The conserved cAMP-dependent protein kinase (PKA) is composed of the regulatory and catalytic subunits and acts as the central component of the cAMP signaling pathway. In the human fungal pathogen Candida albicans, the PKA regulatory subunit Bcy1 plays a critical role in the regulation of cell differentiation and death. It has long been considered that Bcy1 is essential for cell viability in C. albicans. In the current study, surprisingly, we found that Bcy1 is not required for cell growth, and we successfully generated a bcy1/bcy1 null mutant in C. albicans. Deletion of BCY1 leads to multiple cellular morphologies and promotes the development of filaments. Filamentous and smooth colonies are two typical morphological types of the bcy1/bcy1 mutant, which can undergo spontaneous switching between the two types. Cells of filamentous colonies grow better on a number of different culture media and have a higher survival rate than cells of smooth colonies. In addition, deletion of BCY1 significantly increased the frequency of white-to-opaque switching on N-acetylglucosamine (GlcNAc)-containing medium. The bcy1/bcy1 null mutant generated herein provides the field a new resource to study the biological functions of the cAMP signaling pathway in C. albicans.

  10. Candida parapsilosis Protects Premature Intestinal Epithelial Cells from Invasion and Damage by Candida albicans

    PubMed Central

    Gonia, Sara; Archambault, Linda; Shevik, Margaret; Altendahl, Marie; Fellows, Emily; Bliss, Joseph M.; Wheeler, Robert T.; Gale, Cheryl A.

    2017-01-01

    Candida is a leading cause of late-onset sepsis in premature infants and is thought to invade the host via immature or damaged epithelial barriers. We previously showed that the hyphal form of Candida albicans invades and causes damage to premature intestinal epithelial cells (pIECs), whereas the non-hyphal Candida parapsilosis, also a fungal pathogen of neonates, has less invasion and damage abilities. In this study, we investigated the potential for C. parapsilosis to modulate pathogenic interactions of C. albicans with the premature intestine. While a mixed infection with two fungal pathogens may be expected to result in additive or synergistic damage to pIECs, we instead found that C. parapsilosis was able to protect pIECs from invasion and damage by C. albicans. C. albicans-induced pIEC damage was reduced to a similar extent by multiple different C. parapsilosis strains, but strains differed in their ability to inhibit C. albicans invasion of pIECs, with the inhibitory activity correlating with their adhesiveness for C. albicans and epithelial cells. C. parapsilosis cell-free culture fractions were also able to significantly reduce C. albicans adhesion and damage to pIECs. Furthermore, coadministration of C. parapsilosis cell-free fractions with C. albicans was associated with decreased infection and mortality in zebrafish. These results indicate that C. parapsilosis is able to reduce invasion, damage, and virulence functions of C. albicans. Additionally, the results with cellular and cell-free fractions of yeast cultures suggest that inhibition of pathogenic interactions between C. albicans and host cells by C. parapsilosis occurs via secreted molecules as well as by physical contact with the C. parapsilosis cell surface. We propose that non-invasive commensals can be used to inhibit virulence features of pathogens and deserve further study as a non-pharmacological strategy to protect the fragile epithelial barriers of premature infants. PMID:28382297

  11. Detailed comparison of Candida albicans and Candida glabrata biofilms under different conditions and their susceptibility to caspofungin and anidulafungin.

    PubMed

    Kucharíková, Sona; Tournu, Hélène; Lagrou, Katrien; Van Dijck, Patrick; Bujdáková, Helena

    2011-09-01

    Candida biofilm development can be influenced by diverse factors such as substrate, culture medium, carbohydrate source and pH. We have analysed biofilm formation of Candida albicans SC5314 and Candida glabrata ATCC 2001 wild-type strains in the presence of different media (RPMI 1640 versus YNB) and using different pH values (pH 5.6 or 7.0). We determined adhesion and biofilm formation on polystyrene, changes in the expression of adhesin genes during these processes and the susceptibility of mature biofilms to echinocandins. Biofilms formed on polystyrene by both Candida species proved to be influenced strongly by the composition of the medium rather than pH. C. albicans and C. glabrata formed thicker biofilms in RPMI 1640 medium, whereas in YNB medium, both species manifested adhesion rather than characteristic multilayer biofilm architecture. The stimulated biofilm formation in RPMI 1640 medium at pH 7.0 corroborated positively with increased expression of adhesin genes, essential to biofilm formation in vitro, including ALS3 and EAP1 in C. albicans and EPA6 in C. glabrata. The thicker biofilms grown in RPMI 1640 medium were more tolerant to caspofungin and anidulafungin than YNB-grown biofilms. We also observed that mature C. glabrata biofilms were less susceptible in RPMI 1640 medium to echinocandins than C. albicans biofilms. Environmental conditions, i.e. medium and pH, can significantly affect not only biofilm architecture, but also the expression profile of several genes involved during the different stages of biofilm development. In addition, growth conditions may also influence the antifungal-susceptibility profile of fungal populations within biofilm structures. Therefore, before designing any experimental biofilm set-up, it is important to consider the potential influence of external environmental factors on Candida biofilm development.

  12. A Monoclonal Antibody Directed against a Candida albicans Cell Wall Mannoprotein Exerts Three Anti-C. albicans Activities

    PubMed Central

    Moragues, María D.; Omaetxebarria, Miren J.; Elguezabal, Natalia; Sevilla, María J.; Conti, Stefania; Polonelli, Luciano; Pontón, José

    2003-01-01

    Antibodies are believed to play a role in the protection against Candida albicans infections by a number of mechanisms, including the inhibition of adhesion or germ tube formation, opsonization, neutralization of virulence-related enzymes, and direct candidacidal activity. Although some of these biological activities have been demonstrated individually in monoclonal antibodies (MAbs), it is not clear if all these anti-C. albicans activities can be displayed by a single antibody. In this report, we characterized a monoclonal antibody raised against the main target of salivary secretory immunoglobulin A in the cell wall of C. albicans, which exerts three anti-C. albicans activities: (i) inhibition of adherence to HEp-2 cells, (ii) inhibition of germination, and (iii) direct candidacidal activity. MAb C7 reacted with a proteinic epitope from a mannoprotein with a molecular mass of >200 kDa predominantly expressed on the C. albicans germ tube cell wall surface as well as with a number of antigens from Candida lusitaniae, Cryptococcus neoformans, Aspergillus fumigatus, and Scedosporium prolificans. MAb C7 caused a 31.1% inhibition in the adhesion of C. albicans to HEp-2 monolayers and a 55.3% inhibition in the adhesion of C. albicans to buccal epithelial cells, produced a 38.5% decrease in the filamentation of C. albicans, and exhibited a potent fungicidal effect against C. albicans, C. lusitaniae, Cryptococcus neoformans, A. fumigatus, and S. prolificans, showing reductions in fungal growth ranging from 34.2 to 88.7%. The fungicidal activity showed by MAb C7 seems to be related to that reported by antibodies mimicking the activity of a killer toxin produced by the yeast Pichia anomala, since one of these MAbs also reacted with the C. albicans mannoprotein with a molecular mass of >200 kDa. Results presented in this study support the concept of a family of microbicidal antibodies that could be useful in the treatment of a wide range of microbial infections when used

  13. Susceptibility of Candida albicans to new synthetic sulfone derivatives.

    PubMed

    Staniszewska, Monika; Bondaryk, Małgorzata; Ochal, Zbigniew

    2015-02-01

    The influence of halogenated methyl sulfones, i.e. bromodichloromethyl-4-chloro-3-nitrophenyl sulfone (named halogenated methyl sulfone 1), dichloromethyl-4-chloro-3-nitrophenyl sulfone (halogenated methyl sulfone 2), and chlorodibromomethyl-4-hydrazino-3-nitrophenyl sulfone (halogenated methyl sulfone 3), on cell growth inhibition, aspartic protease gene (SAP4-6) expression, adhesion to epithelium, and filamentation was investigated. Antifungal susceptibility of the halogenated methyl sulfones was determined with the M27-A3 protocol in the range of 16-0.0313 µg/mL. Adherence to Caco-2 cells was performed in 24-well plates; relative quantification was normalized against ACT1 in cells after 18 h of growth in YEPD and on Caco-2 cells. SAP4-6 expression was analyzed using RT-PCR. Structure-activity relationship studies suggested that halogenated methyl sulfone 1 containing bromodichloromethyl or dichloromethyl function at C-4 (halogenated methyl sulfone 2) of the phenyl ring showed the best activity (100% cell inhibition at 0.5 µg/mL), while hydrazine at C-1 (halogenated methyl sulfone 3) reduced the sulfone potential (100% = 4 µg/mL). SAP4-6 were up- or down-regulated depending on the strains' genetic background and the substitutions on the phenyl ring. Halogenated methyl sulfone 2 repressed germination and affected adherence to epithelium (P ≤ 0.05). The tested halogenated methyl sulfones interfered with the adhesion of Candida albicans cells to the epithelial tissues, without affecting their viability after 90 min of incubation. The mode of action of the halogenated methyl sulfones was attributed to the reduced virulence of C. albicans. SAP5 and SAP6 contribute to halogenated methyl sulfones resistance. Thus, halogenated methyl sulfones can inhibit biofilm formation due to their interference with adherence and with the yeast-to-hyphae transition.

  14. ENDOTOXIN-INDUCED TOLERANCE TO TOXIC MANIFESTATIONS OF CANDIDA ALBICANS

    PubMed Central

    Hasenclever, H. F.; Mithcell, William O.

    1963-01-01

    Hasenclever, H. F. (National Institutes of Health, Bethesda, Md.) and William O. Mitchell. Endotoxin-induced tolerance to toxic manifestations of Candida albicans. J. Bacteriol. 85:1088–1093. 1963.—Mice exposed to 425 r total body irradiation failed to become tolerant to Candida albicans toxicity after injection with lipopolysaccharide. Mice injected with lipopolysaccharide and then X-rayed did not demonstrate the tolerant state. An injection of thorium dioxide in mice that had previously received tolerance-inducing amounts of lipopolysaccharide rendered them as susceptible to acute C. albicans toxicity as control mice. A bimodal manifestation of tolerance was noted. Groups of mice given single injections of lipopolysaccharide at 6 or 1 days before challenge demonstrated high levels of tolerance, whereas the tolerance in mice given a single dose at 3 days was negligible. The bimodal effect was not observed in tolerant mice challenged with lipopolysaccharide. Injections of viable or nonviable pathogenic fungi known to produce tolerance to the toxicity of C. albicans in recipient mice did not produce tolerance to lipopolysaccharide. Serum from mice injected with lipopolysaccharide showed in vitro inhibitory activity for C. albicans. PMID:14043999

  15. Candida albicans-induced inflammatory response in human keratinocytes.

    PubMed

    Wollina, U; Künkel, W; Bulling, L; Fünfstück, C; Knöll, B; Vennewald, I; Hipler, U-C

    2004-06-01

    Candida albicans strains 3153a, ATCC 48867, CBS 2730, DSM 70014, and Vir 13 were cultivated and sterile C. albicans filtrates were produced. The interaction of soluble Candida factors of these infiltrates with human HaCaT keratinocytes was assayed in vitro. The following parameters were analyzed: cell proliferation, protein synthesis, nuclear matrix protein (NMP) 41 release, cytokine release (IL-1beta, soluble IL-2 receptor, IL-6, and IL-8), and reactive oxygen species (ROS). Cell counts at 1, 12, and 24 h were significantly lower for C. albicans strains CBS 2730 and VIR 13 (P < 0.05). There was no significant change for the remaining strains. Neither the protein synthesis nor the NMP-41 release was significantly affected. IL-6 and IL-8 were stimulated by C. albicans filtrates to different amounts with higher levels in strains of low virulence. There was no effect on the other cytokines. The production of ROS by HaCaT keratinocytes was suppressed. The induction of an inflammatory keratinocyte response by soluble C. albicans factors may play a role among the host-yeast interactions.

  16. Function and subcellular localization of Gcn5, a histone acetyltransferase in Candida albicans.

    PubMed

    Chang, Peng; Fan, Xueyi; Chen, Jiangye

    2015-08-01

    Candida albicans is an opportunistic fungal pathogen commonly found in humans. It has the ability to switch reversibly between three growth forms: budding yeast, pseudohypha, and hypha. The transition between yeast and hyphal growth forms is critical for the pathogenesis of C. albicans. During the yeast-to-hypha morphologic transition, gene expression is regulated by transcriptional regulators including histone modifying complexes and chromatin remodeling complexes. We previously reported that Esa1, a catalytic subunit in the histone acetyltransferase complex NuA4, is essential for the hyphal development of C. albicans. In this study, we analyzed the functional roles of Gcn5, a catalytic subunit in the histone acetyltransferase complex SAGA, in C. albicans. Gcn5 is required for the invasive and filamentous growth of C. albicans. Deletion of GCN5 impaired hyphal elongation in sensing serum and attenuated the virulence of C. albicans in a mouse systemic infection model. The C. albicans gcn5/gcn5 mutant cells also exhibited sensitivity to cell wall stress. Functional analysis showed that the HAT domain and Bromodomain in Gcn5 play distinct roles in morphogenesis and cell wall stress response of C. albicans. Our results show that the conserved residue Glu188 is crucial for the Gcn5 HAT activity and for Gcn5 function during filamentous growth. In addition, the subcellular distribution of ectopically expressed GFP-Gcn5 correlates with the different growth states of C. albicans. In stationary phase, Gcn5 accumulated in the nucleus, while during vegetative growth it localized in the cytoplasm in a morpha-independent manner. Our results suggest that the nuclear localization of Gcn5 depends on the existence of its N-terminal NLS and HAT domains.

  17. Candida albicans and Candida tropicalis in oral candidosis: quantitative analysis, exoenzyme activity, and antifungal drug sensitivity.

    PubMed

    da Costa, Karen Regina Carim; Ferreira, Joseane Cristina; Komesu, Marilena Chinali; Candido, Regina Celia

    2009-02-01

    Candida albicans and C. tropicalis obtained from whole saliva of patients presenting signs of oral candidosis were assayed for quantification of colony forming units, exoenzyme activity (phospholipase and proteinase) and antifungal drug sensitivity (amphotericin B, fluconazole and itraconazole) by the reference method of the Clinical and Laboratory Standards Institute. The number of colony forming units per milliliter varied according to the Candida species involved and whether a single or mixed infection was present. Proteinase activity was observed in both C. albicans and C. tropicalis, but phospholipase activity was noted only in C. albicans. In vitro resistance to antifungals was verified in both species, but C. tropicalis appears to be more resistant to the tested antifungals than C. albicans.

  18. Evaluation of the new chromogenic medium Candida ID 2 for isolation and identification of Candida albicans and other medically important Candida species.

    PubMed

    Eraso, Elena; Moragues, María D; Villar-Vidal, María; Sahand, Ismail H; González-Gómez, Nagore; Pontón, José; Quindós, Guillermo

    2006-09-01

    The usefulness of Candida ID 2 (CAID2) reformulated medium (bioMérieux, France) has been compared with that of the former Candida ID (CAID; bioMérieux), Albicans ID 2 (ALB2; bioMérieux), and CHROMagar Candida (CAC; Chromagar, France) chromogenic media for the isolation and presumptive identification of clinically relevant yeasts. Three hundred forty-five stock strains from culture collections, and 103 fresh isolates from different clinical specimens were evaluated. CAID2 permitted differentiation based on colony color between Candida albicans (cobalt blue; sensitivity, 91.7%; specificity, 97.2%) and Candida dubliniensis (turquoise blue; sensitivity, 97.9%; specificity, 96.6%). Candida tropicalis gave distinguishable pink-bluish colonies in 97.4% of the strains in CAID2 (sensitivity, 97.4%; specificity, 100%); the same proportion was reached in CAC, where colonies were blue-gray (sensitivity, 97.4%; specificity, 98.7%). CAC and CAID2 showed 100% sensitivity values for the identification of Candida krusei. However, with CAID2, experience is required to differentiate the downy aspect of the white colonies of C. krusei from other white-colony-forming species. The new CAID2 medium is a good candidate to replace CAID and ALB2, and it compares well to CAC for culture and presumptive identification of clinically relevant Candida species. CAID2 showed better results than CAC in some aspects, such as quicker growth and color development of colonies from clinical specimens, detection of mixed cultures, and presumptive differentiation between C. albicans and C. dubliniensis.

  19. Evaluation of the New Chromogenic Medium Candida ID 2 for Isolation and Identification of Candida albicans and Other Medically Important Candida Species

    PubMed Central

    Eraso, Elena; Moragues, María D.; Villar-Vidal, María; Sahand, Ismail H.; González-Gómez, Nagore; Pontón, José; Quindós, Guillermo

    2006-01-01

    The usefulness of Candida ID 2 (CAID2) reformulated medium (bioMérieux, France) has been compared with that of the former Candida ID (CAID; bioMérieux), Albicans ID 2 (ALB2; bioMérieux), and CHROMagar Candida (CAC; Chromagar, France) chromogenic media for the isolation and presumptive identification of clinically relevant yeasts. Three hundred forty-five stock strains from culture collections, and 103 fresh isolates from different clinical specimens were evaluated. CAID2 permitted differentiation based on colony color between Candida albicans (cobalt blue; sensitivity, 91.7%; specificity, 97.2%) and Candida dubliniensis (turquoise blue; sensitivity, 97.9%; specificity, 96.6%). Candida tropicalis gave distinguishable pink-bluish colonies in 97.4% of the strains in CAID2 (sensitivity, 97.4%; specificity, 100%); the same proportion was reached in CAC, where colonies were blue-gray (sensitivity, 97.4%; specificity, 98.7%). CAC and CAID2 showed 100% sensitivity values for the identification of Candida krusei. However, with CAID2, experience is required to differentiate the downy aspect of the white colonies of C. krusei from other white-colony-forming species. The new CAID2 medium is a good candidate to replace CAID and ALB2, and it compares well to CAC for culture and presumptive identification of clinically relevant Candida species. CAID2 showed better results than CAC in some aspects, such as quicker growth and color development of colonies from clinical specimens, detection of mixed cultures, and presumptive differentiation between C. albicans and C. dubliniensis. PMID:16954270

  20. Candida albicans specializations for iron homeostasis: from commensalism to virulence.

    PubMed

    Noble, Suzanne M

    2013-12-01

    Candida albicans is a fungal commensal-pathogen that persistently associates with its mammalian hosts. Between the commensal and pathogenic lifestyles, this microorganism inhabits host niches that differ markedly in the levels of bioavailable iron. A number of recent studies have exposed C. albicans specializations for acquiring iron from specific host molecules in regions where iron is scarce, while also defending against iron-related toxicity in regions where iron occurs in surfeit. Together, these results point to a central role for iron homeostasis in the evolution of this important human pathogen.

  1. Collaborative Consensus for Optimized Multilocus Sequence Typing of Candida albicans

    PubMed Central

    Bougnoux, M.-E.; Tavanti, A.; Bouchier, C.; Gow, N. A. R.; Magnier, A.; Davidson, A. D.; Maiden, M. C. J.; d'Enfert, C.; Odds, F. C.

    2003-01-01

    A panel of 86 different Candida albicans isolates was subjected to multilocus sequence typing (MLST) in two laboratories to obtain sequence data for 10 published housekeeping gene fragments. Analysis of data for all possible combinations of five, six, seven, eight, and nine of the fragments showed that a set comprising the fragments AAT1a, ACC1, ADP1, MPIb, SYA1, VPS13, and ZWF1b was the smallest that yielded 86 unique diploid sequence types for the 86 isolates. This set is recommended for future MLST with C. albicans. PMID:14605179

  2. Hemin induces germ tube formation in Candida albicans.

    PubMed Central

    Casanova, M; Cervera, A M; Gozalbo, D; Martínez, J P

    1997-01-01

    Hemin induced germination of Candida albicans blastoconidia when cells grown up to the early exponential phase were shifted from 28 to 37 degrees C (70 to 75% of cells exhibited germ tubes). N-Acetyl-D-glucosamine (GlcNAc), another inducer of myceliation in this fungus, caused a similar effect. The combination of hemin and GlcNAc resulted in a higher percentage (95%) of blastoconidial germination. These results suggest that in addition to temperature, hemin levels and carbon source may coordinately regulate the expression of subsets of genes involved in the yeast-to-mycelium transition in C. albicans. PMID:9317050

  3. Oral Candida albicans carriage in healthy preschool and school children.

    PubMed

    Rozkiewicz, D; Daniluk, T; Zaremba, M L; Cylwik-Rokicka, D; Stokowska, W; Pawińska, M; Dabrowska, E; Marczuk-Kolada, G; Waszkiel, D

    2006-01-01

    The purpose of the present study was to detect Candida albicans carriage in the oral cavity of healthy preschool and school children. The second aim was the determination of correlation between C. albicans occurrence and dental caries in children population. The samples for mycological examinations were collected from the pharynx and supragingival plaque, and carious lesions in 102 children, aged 4-7 years (preschool children) and 104 children and adolescents, aged 12 and 18 (school children). All samples were cultured directly on Sabouraud agar medium. Isolated yeasts were identified based on API 20C AUX (bioMérieux). A total of 123 C. albicans strains were isolated, in which 61 (49.6%) derived from supragingival plaque, 48 (39%)--from carious lesions, and 14 (11.4%)--from pharyngeal swabs. C. albicans was isolated from the samples of single material in 61 children (35--school children, 26 --preschool children) while from the rest of 29 children, C. albicans was isolated from two (25x) or three materials (4x). C. albicans was detected in 48/75 (64%) children with dental caries; the rate was statistically significantly higher as compared to the overall number of children with C. albicans carriage (90/206; 43.7%) (p = 0.0026). Similar results was obtained in preschool children (38/61; 62.3% and 47/102; 46.1%, respectively) (p = 0.0449), as in school children (10/14; 71.4% and 43/104; 41.3%, respectively) (p = 0.0336). 1) Candida albicans was observed in the oral cavity of healthy children with high (approximately 40%)--comparable rate in school and preschool children (p > 0.05). 2) C. albicans was isolated with high comparable rate from carious lesions in preschool and school children. The statistically significant differences between the rate of C. albicans in carious lesions in preschool children (62.3%) and school children (71.4%) and the overall number of children with C. albicans carriage in the oral cavity of children in both age groups (p < 0.05) were showed.

  4. Genotyping Candida albicans from Candida Leukoplakia and Non-Candida Leukoplakia Shows No Enrichment of Multilocus Sequence Typing Clades but Enrichment of ABC Genotype C in Candida Leukoplakia

    PubMed Central

    Flint, Stephen R.; Coleman, David C.

    2013-01-01

    Oral leukoplakias are histopathologically-diagnosed as Candida leukoplakia or non-Candida leukoplakia by the presence or absence of hyphae in the superficial epithelium. Candida leukoplakia lesions have significantly increased malignant potential. Candida albicans is the most prevalent fungal species associated with oral leukoplakia and may contribute to malignant transformation of Candida leukoplakia. To date, no detailed population analysis of C. albicans isolates from oral leukoplakia patients has been undertaken. This study investigated whether specific C. albicans genotypes were associated with Candida leukoplakia and non-Candida leukoplakia in a cohort of Irish patients. Patients with histopathologically-defined Candida leukoplakia (n = 31) or non-Candida leukoplakia (n = 47) were screened for Candida species by culture of oral rinse and lesional swab samples. Selected C. albicans isolates from Candida leukoplakia patients (n = 25), non-Candida leukoplakia patients (n = 19) and oral carriage isolates from age and sex matched healthy subjects without leukoplakia (n = 34) were subjected to multilocus sequence typing (MLST) and ABC genotyping. MLST revealed that the clade distribution of C. albicans from both Candida leukoplakia and non-Candida leukoplakia lesions overlapped with the corresponding clade distributions of oral carriage isolates and global reference isolates from the MLST database indicating no enrichment of leukoplakia-associated clones. Oral leukoplakia isolates were significantly enriched with ABC genotype C (12/44, 27.3%), particularly Candida leukoplakia isolates (9/25, 36%), relative to oral carriage isolates (3/34, 8.8%). Genotype C oral leukoplakia isolates were distributed in MLST clades 1,3,4,5,8,9 and 15, whereas genotype C oral carriage isolates were distributed in MLST clades 4 and 11. PMID:24058485

  5. Genotyping Candida albicans from Candida leukoplakia and non-Candida leukoplakia shows no enrichment of multilocus sequence typing clades but enrichment of ABC genotype C in Candida leukoplakia.

    PubMed

    Abdulrahim, Mohammed H; McManus, Brenda A; Flint, Stephen R; Coleman, David C

    2013-01-01

    Oral leukoplakias are histopathologically-diagnosed as Candida leukoplakia or non-Candida leukoplakia by the presence or absence of hyphae in the superficial epithelium. Candida leukoplakia lesions have significantly increased malignant potential. Candida albicans is the most prevalent fungal species associated with oral leukoplakia and may contribute to malignant transformation of Candida leukoplakia. To date, no detailed population analysis of C. albicans isolates from oral leukoplakia patients has been undertaken. This study investigated whether specific C. albicans genotypes were associated with Candida leukoplakia and non-Candida leukoplakia in a cohort of Irish patients. Patients with histopathologically-defined Candida leukoplakia (n = 31) or non-Candida leukoplakia (n = 47) were screened for Candida species by culture of oral rinse and lesional swab samples. Selected C. albicans isolates from Candida leukoplakia patients (n = 25), non-Candida leukoplakia patients (n = 19) and oral carriage isolates from age and sex matched healthy subjects without leukoplakia (n = 34) were subjected to multilocus sequence typing (MLST) and ABC genotyping. MLST revealed that the clade distribution of C. albicans from both Candida leukoplakia and non-Candida leukoplakia lesions overlapped with the corresponding clade distributions of oral carriage isolates and global reference isolates from the MLST database indicating no enrichment of leukoplakia-associated clones. Oral leukoplakia isolates were significantly enriched with ABC genotype C (12/44, 27.3%), particularly Candida leukoplakia isolates (9/25, 36%), relative to oral carriage isolates (3/34, 8.8%). Genotype C oral leukoplakia isolates were distributed in MLST clades 1,3,4,5,8,9 and 15, whereas genotype C oral carriage isolates were distributed in MLST clades 4 and 11.

  6. Improved medium for fluconazole susceptibility testing of Candida albicans.

    PubMed Central

    Rodriguez-Tudela, J L; Martinez-Suarez, J V

    1994-01-01

    We have compared fluconazole susceptibilities of 92 clinical isolates of Candida albicans by broth microdilution in two different media: standard RPMI 1640 (RPMI) and the same medium supplemented with 18 g of glucose per liter (RPMI-glucose). Preparation of media, drugs, and inocula, as well as incubation conditions, followed the preliminary recommendations of the National Committee for Clinical Laboratory Standards (Villanova, Pa.) antifungal agent working group for broth macrodilution tests with antifungal agents, adapted to microdilution. Microtiter plates were agitated for 5 min before spectrophotometric readings were performed with an automatic plate reader set at 405 mm. The MIC endpoint was defined as an inhibitory concentration calculated from the turbidimetric data as a function of the turbidity in the drug-free control wells. The mean absorbances in the drug-free wells in RPMI and RPMI-glucose were, respectively, 0.38 (41.6% transmission) and 0.99 (10.2% transmission) (P < 0.001; Student's t test). Despite the increased growth in RPMI-glucose, 98.9% of the C. albicans strains tested for fluconazole susceptibility yielded similar MICs (+/- 1 dilution) in both media. Moreover, strains with decreased susceptibility to fluconazole displaying similar MICs in both media are easier to detect in RPMI-glucose because of the greater differences between turbidimetric readings in wells with grown or fluconazole-inhibited cultures. This objective turbidimetric method, with an easy-to-read improved medium (RPMI with glucose), together with previous experience of the National Committee for Clinical Laboratory Standards antifungal agent subcommittee, could overcome some of the present problems associated with lack of reproducibility of azole susceptibility testing. PMID:8141578

  7. A Phenotypic Profile of the Candida albicans Regulatory Network

    PubMed Central

    Homann, Oliver R.; Dea, Jeanselle; Noble, Suzanne M.; Johnson, Alexander D.

    2009-01-01

    Candida albicans is a normal resident of the gastrointestinal tract and also the most prevalent fungal pathogen of humans. It last shared a common ancestor with the model yeast Saccharomyces cerevisiae over 300 million years ago. We describe a collection of 143 genetically matched strains of C. albicans, each of which has been deleted for a specific transcriptional regulator. This collection represents a large fraction of the non-essential transcription circuitry. A phenotypic profile for each mutant was developed using a screen of 55 growth conditions. The results identify the biological roles of many individual transcriptional regulators; for many, this work represents the first description of their functions. For example, a quarter of the strains showed altered colony formation, a phenotype reflecting transitions among yeast, pseudohyphal, and hyphal cell forms. These transitions, which have been closely linked to pathogenesis, have been extensively studied, yet our work nearly doubles the number of transcriptional regulators known to influence them. As a second example, nearly a quarter of the knockout strains affected sensitivity to commonly used antifungal drugs; although a few transcriptional regulators have previously been implicated in susceptibility to these drugs, our work indicates many additional mechanisms of sensitivity and resistance. Finally, our results inform how transcriptional networks evolve. Comparison with the existing S. cerevisiae data (supplemented by additional S. cerevisiae experiments reported here) allows the first systematic analysis of phenotypic conservation by orthologous transcriptional regulators over a large evolutionary distance. We find that, despite the many specific wiring changes documented between these species, the general phenotypes of orthologous transcriptional regulator knockouts are largely conserved. These observations support the idea that many wiring changes affect the detailed architecture of the circuit, but

  8. Comparison of the susceptibilities of clinical isolates of Candida albicans and Candida dubliniensis to essential oils.

    PubMed

    Pozzatti, Patrícia; Loreto, Erico Silva; Lopes, Paulo Guilherme Markus; Athayde, Margareth Linde; Santurio, Janio Morais; Alves, Sydney Hartz

    2010-01-01

    Here, a microdilution technique based on the M27-A2 protocol (NCCLS, 2002) was employed to compare the susceptibilities of Candida albicans and Candida dubliniensis to essential oils extracted from plants used as spices. The chemical compositions of the essential oils were defined based on the analysis of retention indices obtained by gas chromatography-mass spectroscopy. Taken together, the results showed that the activity of the compounds against the two species was similar.

  9. Starvation survival of Candida albicans in various water microcosms.

    PubMed

    Chaieb, Kamel; Kouidhi, Bochra; Zmantar, Tarek; Mahdouani, Kacem; Bakhrouf, Amina

    2011-08-01

    Candida is a major Human pathogen causing a variety of infections and can survive for extended period of time in aquatic environment including marine and fresh water. In this study we compared a colorimetric XTT assay to colony forming units (CFU) count to evaluate the survival potential of Candida albicans incubated in water microcosms. Our results showed that cells maintain cultivability within a long period followed by a decline in cultivability and a drop of plate counts to less than 20 cell ml(-1) after 150 days in tap water, 190 days in rain water and 200 days in seawater. In addition we noted that 10% of cells viability was reached after 150 days in seawater, 180 days in rain water and 210 days in tap water. Molecular method confirms the persistence of C. albicans cells in water during long time starvation period. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. The alternative oxidase of Candida albicans causes reduced fluconazole susceptibility.

    PubMed

    Yan, Lan; Li, Miaohai; Cao, Yongbing; Gao, Pinghui; Cao, Yingying; Wang, Yan; Jiang, Yuanying

    2009-10-01

    To evaluate the effect of Candida albicans mitochondrial respiratory status on antifungal azole susceptibility. The inhibitors cyanide and salicylhydroxamic acid (SHAM) were each combined with azoles to examine the effect of the combinations on C. albicans. C. albicans strains deleted for the alternative oxidase (Aox) were also examined for susceptibility to azoles and for the generation of intracellular reactive oxygen species (ROS). A chequerboard microdilution assay was performed on several C. albicans clinical strains including azole-resistant isolates to explore the combined effect of fluconazole and inhibitors of Aox. The induction of the alternative respiratory pathway by cyanide decreased susceptibility to azoles, while the inhibition of alternative respiration by SHAM increased azole susceptibility. It was found that ROS production was increased in the absence of Aox in C. albicans upon treatment by antifungals such as miconazole and benomyl. The combination of fluconazole with SHAM resulted in a synergistic effect on the killing of C. albicans clinical isolates. These results demonstrate that the induction of the alternative respiratory pathway confers reduced susceptibility to antifungal azoles, potentially through a mechanism that involves decreased intracellular ROS production during exposure to antifungal agents.

  11. Secretory component mediates Candida albicans binding to epithelial cells.

    PubMed

    van der Wielen, P A; Holmes, A R; Cannon, R D

    2016-01-01

    Candida albicans attaches to oral surfaces via a number of mechanisms including adherence mediated by salivary components adsorbed to the C. albicans cell surface. Our goal was to identify the salivary molecules involved. Biotinylated salivary polypeptides that were bound by C. albicans were detected in extracts from washed, saliva-treated yeast cells by polyacrylamide gel electrophoresis and electroblot or immunoblot transfer analysis and purified by electroelution. Purified material was tested for the ability to promote the adherence of radiolabelled C. albicans yeast cells to cultured epithelial monolayers. Three of the polypeptides bound by C. albicans cells were identified as components of secretory IgA, including secretory component. Using non-denaturing polyacrylamide gel electrophoresis, we demonstrated that secretory component could be detected in its free form in saliva, and was bound by yeast cells. Secretory component which was purified by electroelution from non-denaturing PAGE-separated saliva, without detectable complete IgA, promoted adherence of yeast cells to cultured epithelial monolayers in a dose-dependent fashion. These results indicate that despite the inhibitory effect on adherence of IgA specific to C. albicans, IgA components, in particular secretory component, also promote binding to cultured epithelial monolayers. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Effectiveness of magnetic fluid hyperthermia against Candida albicans cells.

    PubMed

    Chudzik, Barbara; Miaskowski, Arkadiusz; Surowiec, Zbigniew; Czernel, Grzegorz; Duluk, Tomasz; Marczuk, Andrzej; Gagoś, Mariusz

    2016-12-01

    Candida albicans is one of the most frequently isolated fungal pathogens causing opportunistic infections in humans. Targeted magnetic fluid hyperthermia (MFH) is a promising method in thermal therapy facilitating selective heating of pathogen cells like C. albicans. In the paper, we used meso-2,3-dimercaptosuccinic acid (DMSA)-coated magnetic nanoparticles (MNPs) and functionalised anti-C. albicans immunomagnetic nanoparticles (IMNPs) to investigate the potential of MFH in combating C. albicans cells in vitro. Using Mössbauer spectroscopy it was found that synthesised MNPs exhibited superparamagnetic phenomena. On the basis of calorimetric experiments, the maximum SAR (specific absorption rate) was found and a proper concentration of MNPs was established to control the temperature. MFH based on both DMSA-coated MNPs and functionalised anti-C. albicans IMNPs was more effective in combating C. albicans cells in vitro than thermostat hyperthermia. Especially promising results were obtained using functionalised IMNPs, which eradicated most of the pathogen colonies at the temperature of 43 °C.

  13. Anti-biofilm Properties of Peganum harmala against Candida albicans

    PubMed Central

    Aboualigalehdari, Elham; Sadeghifard, Nourkhoda; Taherikalani, Morovat; Zargoush, Zaynab; Tahmasebi, Zahra; Badakhsh, Behzad; Rostamzad, Arman; Ghafourian, Sobhan; Pakzad, Iraj

    2016-01-01

    Objectives Vaginitis still remains as a health issue in women. It is notable that Candida albicans producing biofilm is considered a microorganism responsible for vaginitis with hard to treat. Also, Peganum harmala was applied as an anti fungal in treatment for many infections in Iran. Therefore, this study goal to investigate the role of P. harmala in inhibition of biofilm formation in C. albicans. Methods So, 27 C. albicans collected from women with Vaginitis, then subjected for biofilm formation assay. P. harmala was applied as antibiofilm formation in C. albicans. Results Our results demonstrated that P. harmala in concentration of 12 μg/ml easily inhibited strong biofilm formation; while the concentrations of 10 and 6 μg/ml inhibited biofilm formation in moderate and weak biofilm formation C. albicans strains, respectively. Conclusion Hence, the current study presented P. harmala as antibiofilm herbal medicine for C. albicans; but in vivo study suggested to be performed to confirm its effectiveness. PMID:27169010

  14. Streptococcus mutans Can Modulate Biofilm Formation and Attenuate the Virulence of Candida albicans

    PubMed Central

    Barbosa, Júnia Oliveira; Rossoni, Rodnei Dennis; Vilela, Simone Furgeri Godinho; de Alvarenga, Janaína Araújo; Velloso, Marisol dos Santos; Prata, Márcia Cristina de Azevedo; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos

    2016-01-01

    Streptococcus mutans and Candida albicans are found together in the oral biofilms on dental surfaces, but little is known about the ecological interactions between these species. Here, we studied the effects of S. mutans UA159 on the growth and pathogencity of C. albicans. Initially, the effects of S. mutans on the biofilm formation and morphogenesis of C. albicans were tested in vitro. Next, we investigate the influence of S. mutans on pathogenicity of C. albicans using in vivo host models, in which the experimental candidiasis was induced in G. mellonella larvae and analyzed by survival curves, C. albicans count in hemolymph, and quantification of hyphae in the host tissues. In all the tests, we evaluated the direct effects of S. mutans cells, as well as the indirect effects of the subproducts secreted by this microorganism using a bacterial culture filtrate. The in vitro analysis showed that S. mutans cells favored biofilm formation by C. albicans. However, a reduction in biofilm viable cells and inhibition of hyphal growth was observed when C. albicans was in contact with the S. mutans culture filtrate. In the in vivo study, injection of S. mutans cells or S. mutans culture filtrate into G. mellonella larvae infected with C. albicans increased the survival of these animals. Furthermore, a reduction in hyphal formation was observed in larval tissues when C. albicans was associated with S. mutans culture filtrate. These findings suggest that S. mutans can secrete subproducts capable to inhibit the biofilm formation, morphogenesis and pathogenicity of C. albicans, attenuating the experimental candidiasis in G. mellonella model. PMID:26934196

  15. Streptococcus mutans Can Modulate Biofilm Formation and Attenuate the Virulence of Candida albicans.

    PubMed

    Barbosa, Júnia Oliveira; Rossoni, Rodnei Dennis; Vilela, Simone Furgeri Godinho; de Alvarenga, Janaína Araújo; Velloso, Marisol dos Santos; Prata, Márcia Cristina de Azevedo; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos

    2016-01-01

    Streptococcus mutans and Candida albicans are found together in the oral biofilms on dental surfaces, but little is known about the ecological interactions between these species. Here, we studied the effects of S. mutans UA159 on the growth and pathogencity of C. albicans. Initially, the effects of S. mutans on the biofilm formation and morphogenesis of C. albicans were tested in vitro. Next, we investigate the influence of S. mutans on pathogenicity of C. albicans using in vivo host models, in which the experimental candidiasis was induced in G. mellonella larvae and analyzed by survival curves, C. albicans count in hemolymph, and quantification of hyphae in the host tissues. In all the tests, we evaluated the direct effects of S. mutans cells, as well as the indirect effects of the subproducts secreted by this microorganism using a bacterial culture filtrate. The in vitro analysis showed that S. mutans cells favored biofilm formation by C. albicans. However, a reduction in biofilm viable cells and inhibition of hyphal growth was observed when C. albicans was in contact with the S. mutans culture filtrate. In the in vivo study, injection of S. mutans cells or S. mutans culture filtrate into G. mellonella larvae infected with C. albicans increased the survival of these animals. Furthermore, a reduction in hyphal formation was observed in larval tissues when C. albicans was associated with S. mutans culture filtrate. These findings suggest that S. mutans can secrete subproducts capable to inhibit the biofilm formation, morphogenesis and pathogenicity of C. albicans, attenuating the experimental candidiasis in G. mellonella model.

  16. The Extracellular Matrix of Candida albicans Biofilms Impairs Formation of Neutrophil Extracellular Traps

    PubMed Central

    Cabezas-Olcoz, Jonathan; Wang, Steven X.; Huttenlocher, Anna; Ansari, Hamayail; Nett, Jeniel E.

    2016-01-01

    Neutrophils release extracellular traps (NETs) in response to planktonic C. albicans. These complexes composed of DNA, histones, and proteins inhibit Candida growth and dissemination. Considering the resilience of Candida biofilms to host defenses, we examined the neutrophil response to C. albicans during biofilm growth. In contrast to planktonic C. albicans, biofilms triggered negligible release of NETs. Time lapse imaging confirmed the impairment in NET release and revealed neutrophils adhering to hyphae and migrating on the biofilm. NET inhibition depended on an intact extracellular biofilm matrix as physical or genetic disruption of this component resulted in NET release. Biofilm inhibition of NETosis could not be overcome by protein kinase C activation via phorbol myristate acetate (PMA) and was associated with suppression of neutrophil reactive oxygen species (ROS) production. The degree of impaired NET release correlated with resistance to neutrophil attack. The clinical relevance of the role for extracellular matrix in diminishing NET production was corroborated in vivo using a rat catheter model. The C. albicans pmr1Δ/Δ, defective in production of matrix mannan, appeared to elicit a greater abundance of NETs by scanning electron microscopy imaging, which correlated with a decreased fungal burden. Together, these findings show that C. albicans biofilms impair neutrophil response through an inhibitory pathway induced by the extracellular matrix. PMID:27622514

  17. Control of Candida albicans Metabolism and Biofilm Formation by Pseudomonas aeruginosa Phenazines

    PubMed Central

    Morales, Diana K.; Grahl, Nora; Okegbe, Chinweike; Dietrich, Lars E. P.; Jacobs, Nicholas J.; Hogan, Deborah A.

    2013-01-01

    ABSTRACT Candida albicans has developmental programs that govern transitions between yeast and filamentous morphologies and between unattached and biofilm lifestyles. Here, we report that filamentation, intercellular adherence, and biofilm development were inhibited during interactions between Candida albicans and Pseudomonas aeruginosa through the action of P. aeruginosa-produced phenazines. While phenazines are toxic to C. albicans at millimolar concentrations, we found that lower concentrations of any of three different phenazines (pyocyanin, phenazine methosulfate, and phenazine-1-carboxylate) allowed growth but affected the development of C. albicans wrinkled colony biofilms and inhibited the fungal yeast-to-filament transition. Phenazines impaired C. albicans growth on nonfermentable carbon sources and led to increased production of fermentation products (ethanol, glycerol, and acetate) in glucose-containing medium, leading us to propose that phenazines specifically inhibited respiration. Methylene blue, another inhibitor of respiration, also prevented the formation of structured colony biofilms. The inhibition of filamentation and colony wrinkling was not solely due to lowered extracellular pH induced by fermentation. Compared to smooth, unstructured colonies, wrinkled colony biofilms had higher oxygen concentrations within the colony, and wrinkled regions of these colonies had higher levels of respiration. Together, our data suggest that the structure of the fungal biofilm promotes access to oxygen and enhances respiratory metabolism and that the perturbation of respiration by bacterial molecules such as phenazines or compounds with similar activities disrupts these pathways. These findings may suggest new ways to limit fungal biofilms in the context of disease. PMID:23362320

  18. Lactobacillus is able to alter the virulence and the sensitivity profile of Candida albicans.

    PubMed

    Oliveira, V M C; Santos, S S F; Silva, C R G; Jorge, A O C; Leão, M V P

    2016-12-01

    The study investigated whether the interaction with Lactobacillus rhamnosus (ATCC7469) interfere with the expression of virulence factors by Candida albicans (ATCC18804). These micro-organisms were grown in biofilms for 24, 48 and 72 h, Candida was isolated and the expression of the major virulence factors were investigated. The production of phospholipase, protease and haemolysin were observed in appropriate media; observation of germ tubes formation in serum; biofilm formation, after growth in microtitre plates and reading in spectrophotometer. Candida was also tested for antifungal sensitivity to amphotericin B, fluconazole and ketoconazole. The results were compared with the cells of Candida grown in the absence of lactobacilli (control group). Candida cells, which interacted with Lact. rhamnosus (test group), showed significantly lower proteinase and haemolysin activity, when compared with control group. The germ tube formation and biofilm formation capacity also decreased in tested groups, which demonstrated alterations in susceptibility to antifungal drugs. The results suggest that Lact. rhamnosus is able to influence the expression of virulence factors by C. albicans and can alter its antifungal sensitivity profile. These results suggest reduction in the pathogenicity of Candida and improvement in candidiasis therapy and control. © 2016 The Society for Applied Microbiology.

  19. Differences in virulence of clinical isolates of Candida tropicalis and Candida albicans in mice.

    PubMed Central

    Wingard, J R; Dick, J D; Merz, W G; Sandford, G R; Saral, R; Burns, W H

    1982-01-01

    Prior reports from this institution indicated that Candida tropicalis was more pathogenic than C. albicans in oncology patients. Pairs of clinical isolates of C. tropicalis and C. albicans recovered from similar patients at other institutions were examined to determine their relative virulence. After intravenous inoculation in normal mice, three pairs of isolates had no significant differences in the 50% lethal dose, and one C. tropicalis isolate was less virulent than its companion C. albicans isolate. In contrast, in mice treated with antibiotics and cytarabine, an antineoplastic drug which damages the gastrointestinal mucosa and produces granulocytopenia, oral inoculation of yeast cells produced striking differences in the 50% infective dose: each C. tropicalis isolate was more virulent than the companion C. albicans isolate from the same institution. The increased virulence of the C. tropicalis isolates compared with the C. albicans isolates when given orally to compromised mice parallels clinical observations in compromised patients. PMID:6749689

  20. Antagonism of Fluconazole and a Proton Pump Inhibitor against Candida albicans.

    PubMed

    Liu, Ning-Ning; Köhler, Julia R

    2016-02-01

    Hospitalized ill patients, at risk for invasive candidiasis, often receive multiple medications, including proton pump inhibitors (PPIs). The antifungal fluconazole perturbs the vacuolar proton ATPase. The PPI omeprazole antagonized Candida albicans growth inhibition by fluconazole. A C. albicans codon-adapted pHluorin, Ca.pHluorin, was generated to measure cytosolic pH. The fungal cytosol was acidified by omeprazole and realkalinized by coexposure to fluconazole. Vacuolar pH was alkalinized by fluconazole. Off-target effects of any medication on fungal pathogens may occur.

  1. Proteomic Analysis of Azole Resistance in Candida albicans Clinical Isolates

    PubMed Central

    Hooshdaran, Massoumeh Z.; Barker, Katherine S.; Hilliard, George M.; Kusch, Harald; Morschhäuser, Joachim; Rogers, P. David

    2004-01-01

    Changes in protein expression within a matched set of Candida albicans isolates representing the acquisition of azole resistance were examined by two-dimensional polyacrylamide gel electrophoresis and peptide mass fingerprinting. Proteins differentially expressed in association with azole resistance included Grp2p, Ifd1p, Ifd4p, Ifd5p, and Erg10p, a protein involved in the ergosterol biosynthesis pathway. PMID:15215138

  2. Antifungal activity of plant extracts against Candida albicans.

    PubMed

    Perez, C; Suarez, C

    1997-01-01

    In previous papers, we reported the antimicrobial activity of plants used in Argentine folk medicine against different micro-organisms. The present study deals with the screening of 11 of these plants against the opportunistic pathogen fungus Candida albicans. Aqueous extracts 6% p/v (6 mg dry plant per 100 ml of water) were checked against fungus cultures by the agar-well diffusion method. Five extracts showed antifungal activity.

  3. Genome-wide functional analysis in Candida albicans.

    PubMed

    Motaung, Thabiso E; Ells, Ruan; Pohl, Carolina H; Albertyn, Jacobus; Tsilo, Toi J

    2017-02-08

    Candida albicans is an important etiological agent of superficial and life-threatening infections in individuals with compromised immune systems. To date, we know of several overlapping genetic networks that govern virulence attributes in this fungal pathogen. Classical use of deletion mutants has led to the discovery of numerous virulence factors over the years, and genome-wide functional analysis has propelled gene discovery at an even faster pace. Indeed, a number of recent studies using large-scale genetic screens followed by genome-wide functional analysis has allowed for the unbiased discovery of many new genes involved in C. albicans biology. Here we share our perspectives on the role of these studies in analyzing fundamental aspects of C. albicans virulence properties.

  4. Candida albicans and Enterococcus faecalis in the gut

    PubMed Central

    Garsin, Danielle A; Lorenz, Michael C

    2013-01-01

    The fungus Candida albicans and the gram-positive bacterium Enterococcus faecalis are both normal residents of the human gut microbiome and cause opportunistic disseminated infections in immunocompromised individuals. Using a nematode infection model, we recently showed that co-infection resulted in less pathology and less mortality than infection with either species alone and this was partly explained by an interkingdom signaling event in which a bacterial-derived product inhibits hyphal morphogenesis of C. albicans. In this addendum we discuss these findings in the contest of other described bacterial-fungal interactions and recent data suggesting a potentially synergistic relationship between these two species in the mouse gut as well. We suggest that E. faecalis and C. albicans promote a mutually beneficial association with the host, in effect choosing a commensal lifestyle over a pathogenic one. PMID:23941906

  5. Rapid characterisation of Candida albicans by pyrolysis mass spectrometry.

    PubMed

    White, G C; Sisson, P R; Freeman, R; Cookson, B D

    1994-08-01

    Clinical isolates (41) of Candida spp. from three possible outbreaks of nosocomially-acquired infection were compared by pyrolysis mass spectrometry (PMS) and by a combined morphotyping and resistotyping (M-R typing) method. Both systems characterised all the isolates and distinguished one isolate of C. tropicalis and another of C. glabrata from the 39 isolates of C. albicans. Results from both systems suggested that cross-infection with a single strain contributed to two of the outbreaks. In several instances, more than one strain of C. albicans was found amongst multiple isolates from the same patient. PMS is a simple, rapid and objective technique capable of characterising C. albicans isolates; discrimination was similar to M-R typing.

  6. Interaction of Candida albicans with Human Leukocytes and Serum1

    PubMed Central

    Lehrer, Robert I.; Cline, Martin J.

    1969-01-01

    A quantitative assay of candidacidal activity based on differential staining of non-viable Candida albicans by methylene blue was developed and applied to studies of leukocytes from normal individuals and patients with fungal and other infections. Serum factors were necessary for optimal phagocytosis of C. albicans but lacked direct candidacidal activity. Normal human neutrophils (38 studies) killed 29.0 ± 7.4% of ingested C. albicans in 1 hr. Eosinophils and monocytes killed a smaller percentage. Neutrophil candidacidal activity did not require protein or ribonucleic acid synthesis by the leukocyte but was inhibited by anaerobic conditions, potassium cyanide, and colchicine. Leukocytes of a patient with hereditary myeloperoxidase deficiency and of three children with chronic granulomatous disease phagocytized C. albicans normally, yet failed to kill them. Our data suggest that the neutrophil can play an important role in resistance to Candida infection and that the lysosomal enzyme myeloperoxidase and its oxidant substrate hydrogen peroxide are the major participants in neutrophil candidacidal activity. Images PMID:4182532

  7. Novel hydroxamates potentiated in vitro activity of fluconazole against Candida albicans

    PubMed Central

    Paul-Satyaseela, Maneesh; Hariharan, Periasamy; Bharani, Thirunavukkarasu; Franklyne, Jonathan S.; Selvakumar, Thangapazham; Bharathimohan, Kuppusamy; Kumar, Chenniappan Vinoth; Kachhadia, Virendra; Narayanan, Shridhar; Rajagopal, Sridharan; Balasubramanian, Gopalan

    2017-01-01

    A set of 12 novel hydroxamate compounds (NHCs), structurally designed as inhibitors of histone deacetylase (HDAC) enzyme, were synthesized at our facility. These were adamantane derivatives with N-hydroxyacetamide as pharmacophore, and each of these compounds was tested for potentiating activity on fluconazole. The concentration of fluconazole which completely inhibited (concentration of complete inhibition [CCI]) the growth of Candida albicans ATCC 90028 and C. albicans ATCC 64550 was determined by micro-dilution method in the absence and presence of NHCs. The CCI of fluconazole without the NHC combination was 64 μg/ml and 1024 μg/ml against C. albicans ATCC 90028 and C. albicans ATCC 64550, respectively. The majority of the NHCs potentiated the fluconazole activity markedly as CCI of fluconazole against C. albicans ATCC 90028 reduced to 0.25 μg/ml. Similarly, CCI of fluconazole against C. albicans ATCC 64550 reduced to 4–8 μg/ml in combination with majority of NHCs while the best activity was displayed by the compound 1 with a reduction of CCI to 0.5 μg/ml. The study results revealed the potential usage of hydroxamate derivatives, structurally designed as HDAC inhibitors to enhance the activity of fluconazole against C. albicans. PMID:28250687

  8. Barrier activity in Candida albicans mediates pheromone degradation and promotes mating.

    PubMed

    Schaefer, Dana; Côte, Pierre; Whiteway, Malcolm; Bennett, Richard J

    2007-06-01

    Mating in Candida albicans and Saccharomyces cerevisiae is regulated by the secretion of peptide pheromones that initiate the mating process. An important regulator of pheromone activity in S. cerevisiae is barrier activity, involving an extracellular aspartyl protease encoded by the BAR1 gene that degrades the alpha pheromone. We have characterized an equivalent barrier activity in C. albicans and demonstrate that the loss of C. albicans BAR1 activity results in opaque a cells exhibiting hypersensitivity to alpha pheromone. Hypersensitivity to pheromone is clearly seen in halo assays; in response to alpha pheromone, a lawn of C. albicans Deltabar1 mutant cells produces a marked zone in which cell growth is inhibited, whereas wild-type strains fail to show halo formation. C. albicans mutants lacking BAR1 also exhibit a striking mating defect in a cells, but not in alpha cells, due to overstimulation of the response to alpha pheromone. The block to mating occurs prior to cell fusion, as very few mating zygotes were observed in mixes of Deltabar1 a and alpha cells. Finally, in a barrier assay using a highly pheromone-sensitive strain, we were able to demonstrate that barrier activity in C. albicans is dependent on Bar1p. These studies reveal that a barrier activity to alpha pheromone exists in C. albicans and that the activity is analogous to that caused by Bar1p in S. cerevisiae.

  9. Antifungal activity of Rubus chingii extract combined with fluconazole against fluconazole-resistant Candida albicans.

    PubMed

    Han, Bing; Chen, Jia; Yu, Yi-qun; Cao, Yong-bing; Jiang, Yuan-ying

    2016-02-01

    This study aimed to investigate the antifungal activity of Rubus chingii extract in combination with fluconazole (FLC) against FLC-resistant Candida albicans 100 in vitro. A R. chingii extract and FLC-resistant C. albicans fungus suspension were prepared. The minimum inhibitory concentration and fractional inhibitory concentration index of R. chingii extract combined with FLC against C. albicans were determined, after which growth curves for C. albicans treated with R. chingii extract, FLC alone and a combination of these preparations were constructed. Additionally, the mechanisms of drug combination against C. albicans were explored by flow cytometry, gas chromatographic mass spectrometry and drug efflux pump function detection. R. chingii extract combined with FLC showed significant synergy. Flow cytometry suggested that C. albicans cells mainly arrest in G1 and S phases when they have been treated with the drug combination. The drug combination resulted in a marked decrease in the ergosterol content of the cell membrane. Additionally, efflux of Rhodamine 6G decreased with increasing concentrations of R. chingii extract. R. chingii extract combined with FLC has antifungal activity against FLC-resistant C. albicans. © 2016 The Societies and John Wiley & Sons Australia, Ltd.

  10. Presence of extracellular DNA in the Candida albicans biofilm matrix and its contribution to biofilms

    PubMed Central

    Martins, Margarida; Uppuluri, Priya; Thomas, Derek P.; Cleary, Ian A.; Henriques, Mariana; Lopez-Ribot, José L.; Oliveira, Rosário

    2014-01-01

    DNA has been described as a structural component of the extracellular matrix (ECM) in bacterial biofilms. In Candida albicans there is a scarce knowledge concerning the contribution of extracellular DNA (eDNA) to biofilm matrix and overall structure. This work examined the presence and quantified the amount of eDNA in C.albicans biofilm ECM and the effect of DNase treatment and the addition of exogenous DNA on C. albicans biofilm development as indicators of a role for eDNA in biofilm development. We were able to detect the accumulation of eDNA in biofilm ECM extracted from C. albicans biofilms formed under conditions of flow, although the quantity of eDNA detected differed according to growth conditions, in particular with regards to the medium used to grow the biofilms. Experiments with C. albicans biofilms formed statically using a microtiter plate model indicated that the addition of exogenous DNA (>160 ng/ml) increases biofilm biomass and, conversely, DNase treatment (>0.03 mg/ml) decreases biofilm biomass at later time points of biofilm development. We present evidence for the role of eDNA in C. albicans biofilm structure and formation, consistent with eDNA being a key element of the ECM in mature C. albicans biofilms and playing a predominant role in biofilm structural integrity and maintenance. PMID:20012895

  11. Presence of extracellular DNA in the Candida albicans biofilm matrix and its contribution to biofilms.

    PubMed

    Martins, Margarida; Uppuluri, Priya; Thomas, Derek P; Cleary, Ian A; Henriques, Mariana; Lopez-Ribot, José L; Oliveira, Rosário

    2010-05-01

    DNA has been described as a structural component of the extracellular matrix (ECM) in bacterial biofilms. In Candida albicans, there is a scarce knowledge concerning the contribution of extracellular DNA (eDNA) to biofilm matrix and overall structure. This work examined the presence and quantified the amount of eDNA in C. albicans biofilm ECM and the effect of DNase treatment and the addition of exogenous DNA on C. albicans biofilm development as indicators of a role for eDNA in biofilm development. We were able to detect the accumulation of eDNA in biofilm ECM extracted from C. albicans biofilms formed under conditions of flow, although the quantity of eDNA detected differed according to growth conditions, in particular with regards to the medium used to grow the biofilms. Experiments with C. albicans biofilms formed statically using a microtiter plate model indicated that the addition of exogenous DNA (>160 ng/ml) increases biofilm biomass and, conversely, DNase treatment (>0.03 mg/ml) decreases biofilm biomass at later time points of biofilm development. We present evidence for the role of eDNA in C. albicans biofilm structure and formation, consistent with eDNA being a key element of the ECM in mature C. albicans biofilms and playing a predominant role in biofilm structural integrity and maintenance.

  12. Hyphal formation of Candida albicans is controlled by electron transfer system

    SciTech Connect

    Watanabe, Toshihiko . E-mail: twatanab@tohoku-pharm.ac.jp; Ogasawara, Ayako; Mikami, Takeshi; Matsumoto, Tatsuji

    2006-09-15

    Most Candida albicans cells cultured in RPMI1640 medium at 37 deg. C grow in hyphal form in aerobic conditions, but they grow in yeast form in anaerobic conditions. The hyphal growth of C. albicans was inhibited in glucose-deficient conditions. Malonic acid, an inhibitor of succinate dehydrogenase, enhanced the yeast proliferation of C. albicans, indicating that the hyphal-formation signal was derived from the glycolysis system and the signal was transmitted to the electron transfer system via the citric acid cycle. Thenoyl trifluoro acetone (TTFA), an inhibitor of the signal transmission between complex II and Co Q, significantly inhibited the hyphal growth of C. albicans. Antimycin, KCN, and oligomycin, inhibitors of complex III, IV, and V, respectively, did not inhibit the hyphal growth of C. albicans. The production of mRNAs for the hyphal formation signal was completely inhibited in anaerobic conditions. These results indicate that the electron transfer system functions upstream of the RAS1 signal pathway and activates the expression of the hyphal formation signal. Since the electron transfer system is inactivated in anaerobic conditions, C. albicans grew in yeast form in this condition.

  13. The transcription factor Flo8 mediates CO2 sensing in the human fungal pathogen Candida albicans

    PubMed Central

    Du, Han; Guan, Guobo; Xie, Jing; Cottier, Fabien; Sun, Yuan; Jia, Wei; Mühlschlegel, Fritz A.; Huang, Guanghua

    2012-01-01

    Physiological levels of CO2 have a profound impact on prominent biological attributes of the major fungal pathogen of humans, Candida albicans. Elevated CO2 induces filamentous growth and promotes white-to-opaque switching. However, the underlying molecular mechanisms of CO2 sensing in C. albicans are insufficiently understood. Here we identify the transcription factor Flo8 as a key regulator of CO2-induced morphogenesis in C. albicans by screening a gene null mutant library. We show that Flo8 is required for CO2-induced white-to-opaque switching, as well as for filamentous growth. Ectopic expression of FLO8 hypersensitizes C. albicans cells to the elevated CO2 levels. Furthermore, we demonstrate that CO2 signaling in C. albicans involves two pathways: the already reported cAMP/protein kinase A and another major one that is unidentified. The two pathways converge on the transcription factor Flo8, which is the master regulator of CO2 sensing in C. albicans and plays a critical role in regulation of white-to-opaque switching and filamentous growth. Our findings provide new insights into the understanding of CO2 sensing in pathogenic fungi that have important implications for higher organisms. PMID:22621896

  14. Anaerobic bacteria grow within Candida albicans biofilms and induce biofilm formation in suspension cultures.

    PubMed

    Fox, Emily P; Cowley, Elise S; Nobile, Clarissa J; Hartooni, Nairi; Newman, Dianne K; Johnson, Alexander D

    2014-10-20

    The human microbiome contains diverse microorganisms, which share and compete for the same environmental niches. A major microbial growth form in the human body is the biofilm state, where tightly packed bacterial, archaeal, and fungal cells must cooperate and/or compete for resources in order to survive. We examined mixed biofilms composed of the major fungal species of the gut microbiome, Candida albicans, and each of five prevalent bacterial gastrointestinal inhabitants: Bacteroides fragilis, Clostridium perfringens, Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. We observed that biofilms formed by C. albicans provide a hypoxic microenvironment that supports the growth of two anaerobic bacteria, even when cultured in ambient oxic conditions that are normally toxic to the bacteria. We also found that coculture with bacteria in biofilms induces massive gene expression changes in C. albicans, including upregulation of WOR1, which encodes a transcription regulator that controls a phenotypic switch in C. albicans, from the "white" cell type to the "opaque" cell type. Finally, we observed that in suspension cultures, C. perfringens induces aggregation of C. albicans into "mini-biofilms," which allow C. perfringens cells to survive in a normally toxic environment. This work indicates that bacteria and C. albicans interactions modulate the local chemistry of their environment in multiple ways to create niches favorable to their growth and survival. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Antifungal activity of extracts and isolated compounds from Buchenavia tomentosa on Candida albicans and non-albicans.

    PubMed

    Teodoro, Guilherme R; Brighenti, Fernanda L; Delbem, Alberto C Botazzo; Delbem, Ádina Cléia B; Khouri, Sonia; Gontijo, Aline Vidal L; Pascoal, Aislan Crf; Salvador, Marcos J; Koga-Ito, Cristiane Y

    2015-01-01

    This study aimed to evaluate the antifungal activity of Buchenavia tomentosa extract and bioactive compounds on six Candida species. The antimicrobial activity of extract was evaluated using standard strains and clinical isolates. Cytotoxicity was tested in order to evaluate cell damage caused by the extract. Extract was chemically characterized and the antifungal activity of its compounds was evaluated. Extract showed antifungal activity on Candida species. Candida non-albicans were more susceptible than Candida albicans. Low cytotoxicity for extract was observed. The isolated compounds presented antifungal activity at least against one Candida spp. and all compounds presented antifungal effect on Candida glabrata. Extracts from Buchenavia tomentosa showed promising antifungal activity on Candida species with low cytotoxicity. Gallic acid, corilagin and ellagic acid showed promising inhibitory activity on Candida glabrata.

  16. Candida albicans Is Resistant to Polyglutamine Aggregation and Toxicity

    PubMed Central

    Leach, Michelle D.; Kim, TaeHyung; DiGregorio, Sonja E.; Collins, Cathy; Zhang, Zhaolei; Duennwald, Martin L.; Cowen, Leah E.

    2016-01-01

    Disruption of protein quality control can be detrimental, having toxic effects on single cell organisms and contributing to neurodegenerative diseases such as Alzheimer’s, Parkinson’s and Huntington’s in humans. Here, we examined the effects of polyglutamine (polyQ) aggregation in a major fungal pathogen of humans, Candida albicans, with the goal of identifying new approaches to disable this fungus. However, we discovered that expression of polyQ stretches up to 230Q had no effect on C. albicans ability to grow and withstand proteotoxic stress. Bioinformatics analysis demonstrates that C. albicans has a similarly glutamine-rich proteome to the unicellular fungus Saccharomyces cerevisiae, which exhibits polyQ toxicity with as few as 72Q. Surprisingly, global transcriptional profiles indicated no significant change upon induction of up to 230Q. Proteomic analysis highlighted two key interactors of 230Q, Sis1 and Sgt2; however, loss of either protein had no additional effect on C. albicans toxicity. Our data suggest that C. albicans has evolved powerful mechanisms to overcome the toxicity associated with aggregation-prone proteins, providing a unique model for studying polyQ-associated diseases. PMID:27807047

  17. Intrauterine Candida albicans infection elicits severe inflammation in fetal sheep

    PubMed Central

    Payne, Matthew S.; Kemp, Matthew W.; Kallapur, Suhas G.; Kannan, Paranthaman Senthamarai; Saito, Masatoshi; Miura, Yuichiro; Newnham, John P.; Stock, Sarah; Ireland, Demelza J.; Kramer, Boris W.; Jobe, Alan H.

    2014-01-01

    Background Preventing preterm birth and subsequent adverse neonatal sequelae is among the greatest clinical challenges of our time. Recent studies suggest a role for Candida spp. in preterm birth and fetal injury, as a result of their colonization of either the vagina and/or the amniotic cavity. We hypothesised that intraamniotic C. albicans would cause a vigorous, acute fetal inflammatory response. Methods Sheep carrying singleton pregnancies received single intraamniotic (IA) injections of either saline (control) or 107 CFU C. albicans 1 or 2 d prior to surgical delivery and euthanasia at 124 ± 2 d gestation. Results Colonization of the amniotic cavity by C. albicans resulted in a modest inflammatory response at 1 d and florid inflammation at 2 d, characterised by fetal thrombocytopenia, lymphopenia and significant increases of inflammatory cytokines/chemokines in the fetal membranes skin, lung and the amniotic fluid. Conclusion Acute colonization of the amniotic cavity by C. albicans causes severe intrauterine inflammation and fetal injury. C. albicans is a potent fetal pathogen which can contribute to adverse pregnancy outcomes. PMID:24632681

  18. A Photonic Crystal Protein Hydrogel Sensor for Candida albicans.

    PubMed

    Cai, Zhongyu; Kwak, Daniel H; Punihaole, David; Hong, Zhenmin; Velankar, Sachin S; Liu, Xinyu; Asher, Sanford A

    2015-10-26

    We report two-dimensional (2D) photonic crystal (PC) sensing materials that selectively detect Candida albicans (C. albicans). These sensors utilize Concanavalin A (Con A) protein hydrogels with a 2D PC embedded on the Con A protein hydrogel surface, that multivalently and selectively bind to mannan on the C. albicans cell surface to form crosslinks. The resulting crosslinks shrink the Con A protein hydrogel, reduce the 2D PC particle spacing, and blue-shift the light diffracted from the PC. The diffraction shifts can be visually monitored, measured with a spectrometer, or determined from the Debye diffraction ring diameter. Our unoptimized hydrogel sensor has a detection limit of around 32 CFU/mL for C. albicans. This sensor distinguishes between C. albicans and those microbes devoid of cell-surface mannan such as the gram-negative bacterium E. coli. This sensor provides a proof-of-concept for utilizing recognition between lectins and microbial cell surface carbohydrates to detect microorganisms in aqueous environments.

  19. Molecular cloning and characterization of the Candida albicans enolase gene.

    PubMed Central

    Mason, A B; Buckley, H R; Gorman, J A

    1993-01-01

    A DNA clone containing the putative Candida albicans enolase gene (ENO1) was isolated from a genomic DNA library. The sequenced insert contained a continuous open reading frame of 1,320 bp. The predicted 440-amino-acid protein is 78 and 76% identical, respectively, to Saccharomyces cerevisiae enolase proteins 1 and 2. Only one enolase gene could be detected in C. albicans genomic DNA by Southern analysis with a homologous probe. Northern (RNA) analysis detected a single, abundant C. albicans ENO1 transcript of approximately 1,600 nucleotides. When cells were grown on glucose, levels of ENO1 mRNA were markedly increased by comparison with ENO1 mRNA levels in cells grown on ethanol, a gluconeogenic carbon source. In contrast to this glucose-mediated transcriptional induction, the carbon source had no dramatic effect on the levels of enolase protein or enzyme activity in the C. albicans strains tested. These results suggest that posttranscriptional mechanisms are responsible for modulating expression of the C. albicans enolase gene. Images PMID:8478328

  20. Oxidative Stress Responses in the Human Fungal Pathogen, Candida albicans

    PubMed Central

    da Silva Dantas, Alessandra; Day, Alison; Ikeh, Mélanie; Kos, Iaroslava; Achan, Beatrice; Quinn, Janet

    2015-01-01

    Candida albicans is a major fungal pathogen of humans, causing approximately 400,000 life-threatening systemic infections world-wide each year in severely immunocompromised patients. An important fungicidal mechanism employed by innate immune cells involves the generation of toxic reactive oxygen species (ROS), such as superoxide and hydrogen peroxide. Consequently, there is much interest in the strategies employed by C. albicans to evade the oxidative killing by macrophages and neutrophils. Our understanding of how C. albicans senses and responds to ROS has significantly increased in recent years. Key findings include the observations that hydrogen peroxide triggers the filamentation of this polymorphic fungus and that a superoxide dismutase enzyme with a novel mode of action is expressed at the cell surface of C. albicans. Furthermore, recent studies have indicated that combinations of the chemical stresses generated by phagocytes can actively prevent C. albicans oxidative stress responses through a mechanism termed the stress pathway interference. In this review, we present an up-date of our current understanding of the role and regulation of oxidative stress responses in this important human fungal pathogen. PMID:25723552

  1. Tumor necrosis factor and interleukin-6 in Candida albicans infection in normal and granulocytopenic mice.

    PubMed Central

    Steinshamn, S; Waage, A

    1992-01-01

    We administered a neutralizing monoclonal antibody to tumor necrosis factor (TNF) during infection with Candida albicans in normal and granulocytopenic mice. Mice were rendered granulocytopenic (less than 0.1 x 10(9) granulocytes per liter) with cyclophosphamide. Growth of C. albicans from the kidneys was significantly increased in normal mice treated with the antibody to TNF, compared with that in control mice, after 36 h (3.6 x 10(4) +/- 1.2 x 10(4) CFU per kidney versus 9.1 x 10(3) +/- 6.2 x 10(3) CFU per kidney; P less than 0.05) and after 72 h (3.7 x 10(6) +/- 2.7 x 10(6) CFU per kidney versus 2.3 x 10(4) +/- 1.3 x 10(4) CFU per kidney; P less than 0.01). In granulocytopenic mice, the antibody to TNF had no effect on the growth of C. albicans from the kidneys. Furthermore, our study showed that the cytokines TNF and interleukin-6 (IL-6) were produced in a dose-dependent manner during C. albicans infection. TNF was detectable between 6 and 60 h, with peak levels at 24 h. Both TNF and IL-6 levels were significantly higher in cyclophosphamide-treated mice than in normal mice. Heat-inactivated C. albicans induced a TNF response different from that induced by viable C. albicans, with an early peak occurring at 3 to 4 h and declining to non-detectable levels after 15 to 24 h. Peak levels of TNF obtained with heat-inactivated C. albicans were lower than those obtained with viable C. albicans. Our study demonstrates that TNF and IL-6 are produced systemically during C. albicans infection and suggests that TNF is essential for granulocyte antifungal activity in vivo. Images PMID:1398912

  2. In vitro activity of Caspofungin combined with Fluconazole on mixed Candida albicans and Candida glabrata biofilm.

    PubMed

    Pesee, Siripen; Angkananuwat, Chayanit; Tancharoensukjit, Sudarat; Muanmai, Somporn; Sirivan, Pattaraporn; Bubphawas, Manita; Tanarerkchai, Nissara

    2016-05-01

    The objective of this study was to evaluate the antifungal effect of caspofungin (CAS) combined with fluconazole (FLU) on the biofilm biomass and cultivable viability and microstructure of Candida albicans and Candida glabrata mixed biofilm in vitro.Biofilms were formed in a 96-well microtiter plate for crystal violet assay and colony forming unit (CFU) method and grown on plastic coverslip disks for scanning electron microscopy. MIC50 of CAS and FLU against single Candida spp.and mixed Candida spp.biofilms were evaluated using crystal violet assay. Additional,C. albicans and C. glabrata mixed biofilms were incubated with subinhibitory CAS concentration plus FLU and their percentages of Candida biofilm reduction were calculated. We found that percentages of biofilm reduction were significantly decreased when CAS at 0.25MIC and FLU (0.25 or 0.5MIC) were combined (P< .05) but not different when CAS at 0.5 MIC combined with FLU at 0.25 or 0.5MIC, compared to CAS treatment alone. Structural analyses revealed that CAS/FLU combination-treated biofilms showed less hyphae and blastospores with some aberrant cells compared to control group. Although it was evident that a greater CFU of Candida glabrata were demonstrated in every group, the total viable cells derived from CAS/FLU combination-treated biofilms at any ratio were not significantly different from positive control. Overall, CAS/FLU combinations appeared to affect the quantity and cell architecture, but number of viable cell, of Candida albicans and Candida glabrata mixed biofilm. This antifungal effect was CAS concentration dependent.

  3. Candida albicans INT1-Induced Filamentation in Saccharomyces cerevisiae Depends on Sla2p

    PubMed Central

    Asleson, Catherine M.; Bensen, Eric S.; Gale, Cheryl A.; Melms, A.-S.; Kurischko, Cornelia; Berman, Judith

    2001-01-01

    The Candida albicans INT1 gene is important for hyphal morphogenesis, adherence, and virulence (C. Gale, C. Bendel, M. McClellan, M. Hauser, J. M. Becker, J. Berman, and M. Hostetter, Science 279:1355–1358, 1998). The ability to switch between yeast and hyphal morphologies is an important virulence factor in this fungal pathogen. When INT1 is expressed in Saccharomyces cerevisiae, cells grow with a filamentous morphology that we exploited to gain insights into how C. albicans regulates hyphal growth. In S. cerevisiae, INT1-induced filamentous growth was affected by a small subset of actin mutations and a limited set of actin-interacting proteins including Sla2p, an S. cerevisiae protein with similarity in its C terminus to mouse talin. Interestingly, while SLA2 was required for INT1-induced filamentous growth, it was not required for polarized growth in response to several other conditions, suggesting that Sla2p is not required for polarized growth per se. The morphogenesis checkpoint, mediated by Swe1p, contributes to INT1-induced filamentous growth; however, epistasis analysis suggests that Sla2p and Swe1p contribute to INT1-induced filamentous growth through independent pathways. The C. albicans SLA2 homolog (CaSLA2) complements S. cerevisiae sla2Δ mutants for growth at 37°C and INT1-induced filamentous growth. Furthermore, in a C. albicans Casla2/Casla2 strain, hyphal growth did not occur in response to either nutrient deprivation or to potent stimuli, such as mammalian serum. Thus, through analysis of INT1-induced filamentous growth in S. cerevisiae, we have identified a C. albicans gene, SLA2, that is required for hyphal growth in C. albicans. PMID:11158313

  4. Enterococcus faecalis Inhibits Hyphal Morphogenesis and Virulence of Candida albicans

    PubMed Central

    Cruz, Melissa R.; Graham, Carrie E.; Gagliano, Bryce C.

    2013-01-01

    The Gram-positive bacterium Enterococcus faecalis and the fungus Candida albicans are both found as commensals in many of the same niches of the human body, such as the oral cavity and gastrointestinal (GI) tract. However, both are opportunistic pathogens and have frequently been found to be coconstituents of polymicrobial infections. Despite these features in common, there has been little investigation into whether these microbes affect one another in a biologically significant manner. Using a Caenorhabditis elegans model of polymicrobial infection, we discovered that E. faecalis and C. albicans negatively impact each other's virulence. Much of the negative effect of E. faecalis on C. albicans was due to the inhibition of C. albicans hyphal morphogenesis, a developmental program crucial to C. albicans pathogenicity. We discovered that the inhibition was partially dependent on the Fsr quorum-sensing system, a major regulator of virulence in E. faecalis. Specifically, two proteases regulated by Fsr, GelE and SerE, were partially required. Further characterization of the inhibitory signal revealed that it is secreted into the supernatant, is heat resistant, and is between 3 and 10 kDa. The substance was also shown to inhibit C. albicans filamentation in the context of an in vitro biofilm. Finally, a screen of an E. faecalis transposon mutant library identified other genes required for suppression of C. albicans hyphal formation. Overall, we demonstrate a biologically relevant interaction between two clinically important microbes that could affect treatment strategies as well as impact our understanding of interkingdom signaling and sensing in the human-associated microbiome. PMID:23115035

  5. Spaceflight enhances cell aggregation and random budding in Candida albicans.

    PubMed

    Crabbé, Aurélie; Nielsen-Preiss, Sheila M; Woolley, Christine M; Barrila, Jennifer; Buchanan, Kent; McCracken, James; Inglis, Diane O; Searles, Stephen C; Nelman-Gonzalez, Mayra A; Ott, C Mark; Wilson, James W; Pierson, Duane L; Stefanyshyn-Piper, Heidemarie M; Hyman, Linda E; Nickerson, Cheryl A

    2013-01-01

    This study presents the first global transcriptional profiling and phenotypic characterization of the major human opportunistic fungal pathogen, Candida albicans, grown in spaceflight conditions. Microarray analysis revealed that C. albicans subjected to short-term spaceflight culture differentially regulated 452 genes compared to synchronous ground controls, which represented 8.3% of the analyzed ORFs. Spaceflight-cultured C. albicans-induced genes involved in cell aggregation (similar to flocculation), which was validated by microscopic and flow cytometry analysis. We also observed enhanced random budding of spaceflight-cultured cells as opposed to bipolar budding patterns for ground samples, in accordance with the gene expression data. Furthermore, genes involved in antifungal agent and stress resistance were differentially regulated in spaceflight, including induction of ABC transporters and members of the major facilitator family, downregulation of ergosterol-encoding genes, and upregulation of genes involved in oxidative stress resistance. Finally, downregulation of genes involved in actin cytoskeleton was observed. Interestingly, the transcriptional regulator Cap1 and over 30% of the Cap1 regulon was differentially expressed in spaceflight-cultured C. albicans. A potential role for Cap1 in the spaceflight response of C. albicans is suggested, as this regulator is involved in random budding, cell aggregation, and oxidative stress resistance; all related to observed spaceflight-associated changes of C. albicans. While culture of C. albicans in microgravity potentiates a global change in gene expression that could induce a virulence-related phenotype, no increased virulence in a murine intraperitoneal (i.p.) infection model was observed under the conditions of this study. Collectively, our data represent an important basis for the assessment of the risk that commensal flora could play during human spaceflight missions. Furthermore, since the low fluid

  6. Cellular Components Mediating Coadherence of Candida albicans and Fusobacterium nucleatum

    PubMed Central

    Wu, T.; Cen, L.; Kaplan, C.; Zhou, X.; Lux, R.; Shi, W.; He, X.

    2015-01-01

    Candida albicans is an opportunistic fungal pathogen found as part of the normal oral flora. It can be coisolated with Fusobacterium nucleatum, an opportunistic bacterial pathogen, from oral disease sites, such as those involved in refractory periodontitis and pulp necrosis. The physical coadherence between these 2 clinically important microbes has been well documented and suggested to play a role in facilitating their oral colonization and colocalization and contributing to polymicrobial pathogenesis. Previous studies indicated that the physical interaction between C. albicans and F. nucleatum was mediated by the carbohydrate components on the surface of C. albicans and the protein components on the Fusobaterium cell surface. However, the identities of the components involved still remain elusive. This study was aimed at identifying the genetic determinants involved in coaggregation between the 2 species. By screening a C. albicans SN152 mutant library and a panel of F. nucleatum 23726 outer membrane protein mutants, we identified FLO9, which encodes a putative adhesin-like cell wall mannoprotein of C. albicans and radD, an arginine-inhibitable adhesin-encoding gene in F. nucleatum that is involved in interspecies coadherence. Consistent with these findings, we demonstrated that the strong coaggregation between wild-type F. nucleatum 23726 and C. albicans SN152 in an in vitro assay could be greatly inhibited by arginine and mannose. Our study also suggested a complex multifaceted mechanism underlying physical interaction between C. albicans and F. nucleatum and for the first time revealed the identity of major genetic components involved in mediating the coaggregation. These observations provide useful knowledge for developing new targeted treatments for disrupting interactions between these 2 clinically relevant pathogens. PMID:26152186

  7. Direct bioethanol production by amylolytic yeast Candida albicans.

    PubMed

    Aruna, A; Nagavalli, M; Girijashankar, V; Ponamgi, S P D; Swathisree, V; Rao, L Venkateswar

    2015-03-01

    An attempt was made to produce bioethanol using optimized fermentation parameters and mutationally improved strain of Candida albicans. The mutant strain OMC3E6 obtained by UV irradiation followed by ethidium bromide successive mutations showed 2.6 times more glucoamylase secretion and 1.5 times more bioethanol production via direct conversion of starch. Enhanced hydrolysis of insoluble starch (72%) and potato starch (70%) was achieved with glucoamylase enzyme preparation from mutant C. albicans. In fermentation medium, the use of maltose, corn steep liquor, NaH2 PO4 , NaCl + MgSO4 and Triton X-100 has increased the glucoamylase production by the microbe. Under optimized conditions, C. albicans eventually produced 437 g ethanol kg(-1) potatoes. Earlier reports mentioned the use of thrice the quantity of starch as reported by us followed by more fermentation period (3-4 days) and demanded pretreatment of starch sources with alpha-amylase as well. Here, we simplified these three steps and obtained 73% conversion of insoluble starch into ethanol via direct conversion method in a period of 2 days without the involvement of cell immobilizations or enzyme pretreatment steps. Due to fast depletion of fossil fuels in the modern world, bioethanol usage as an alternate energy source is the need of the hour. For the first time, we report bioethanol production by Candida albicans via direct conversion of starchy biomass into ethanol along with enhanced starch-hydrolysing capacity and ethanol conversion ratio. So far, C. albicans was dealt in the field of clinical pathology, but here we successfully employed this organism to produce bioethanol from starchy agri-substrates. Optimizing fermentation parameters and improving the microbial strains through successive mutagenesis can improve the end product yield. © 2014 The Society for Applied Microbiology.

  8. Phenotypic switch: The enigmatic white-gray-opaque transition system of Candida albicans.

    PubMed

    Bommanavar, Sushma Basavaraj; Gugwad, Sachin; Malik, Neelima

    2017-01-01

    Candida albicans represents the most common commensal and opportunistic fungal pathogen colonizing humans. As a member of the normal microflora, it is present on the skin and the mucous membranes of the upper respiratory tract, gastrointestinal tract and female genital tracts. It is therefore not transmitted. It lies in wait for a change in some aspect of the host physiology that normally suppress growth and invasiveness through an enigmatic phenomenon called Phenotypic Switch System or White-Opaque Transition. This system involves reversible and heritable switching between alternative cellular phenotypes. White-opaque switching in Candida albicans was first discovered in 1987. This was initially identified in strain WO-1. Switching has been demonstrated to occur at sites of infection and to occur between recurrent episodes of infection in select cases esp. AIDS and diabetes.

  9. Biofilm inhibition by Cymbopogon citratus and Syzygium aromaticum essential oils in the strains of Candida albicans.

    PubMed

    Khan, Mohd Sajjad Ahmad; Ahmad, Iqbal

    2012-03-27

    Oils of Cymbopogon citratus and Syzygium aromaticum have been used in traditional medicine to treat fungal infections of skin, mouth, urinary and vaginal tract in Asian countries particularly India and other developing countries. To evaluate essential oils of Cymbopogon citratus and Syzygium aromaticum for their anti-biofilm activity against strong biofilm forming strains of Candida albicans. XTT reduction assay, Time kill assays, light microscopy and scanning electron microscopy (SEM) were employed to determine the effect of test oils on the Candida albicans biofilms. Most of the Candida albicans strains tested displayed formation of moderate to strong biofilms. Preformed Candida biofilms showed ≥1024 times increased resistance to antifungal drugs, 2 times to Syzygium aromaticum, but no increased tolerance for Cymbopogon citratus. Test oils were more active against preformed biofilms compared to amphotericin B and fluconazole. At 0.5× MIC, Cymbopogon citratus followed by Syzygium aromaticum were most inhibitory against biofilm formation. Light and electron microscopic studies revealed the deformity of three dimensional structures of biofilms formed in the presence of sub-MICs of Cymbopogon citratus. The cell membranes appeared to be the target site of compounds in sessile cells as displayed by SEM observations. Our data had demonstrated promising in vitro anti-biofilm activity by Cymbopogon citratus and Syzygium aromaticum and confirm the ethnopharmacological use of these oils in muco-cutaneous Candida infections. Furthermore, it suggests exploitation of these oils as new anti-biofilm products to deal with the problem of drug-resistance and recurrent infection associated with biofilm mode of growth of Candida spp. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Mechanisms of interaction between Candida albicans and Streptococcus mutans: an experimental and mathematical modelling study.

    PubMed

    Brusca, Maria I; Irastorza, Ramiro M; Cattoni, Diego I; Ozu, Marcelo; Chara, Osvaldo

    2013-01-01

    To evaluate the mechanisms of microbial interaction between the oral pathogens Candida albicans and Streptococcus mutans. Growth kinetics for the two micro-organisms, cultured individually or together, were followed experimentally for 36 h. The different growth curves were analysed by means of mathematical modelling. Under the experimental conditions, S. mutans final concentration, when grown individually, was 5-times that of C. albicans. Contrarily, when both micro-organisms grew together, this ratio was inversed and C. albicans final concentration was even higher than that of S. mutans. When both micro-organisms share the niche, a model including linear competition among one another was best suited to reproduce the experimental observations. The results of this model show that the initial growth rates of both species are positively influenced by their mutual interaction. However, at longer incubation times, C. albicans prevents bacterial growth and achieves concentrations 4-times higher than when grown individually. The results suggest that C. albicans biofilm formation could be potentiated by the presence of S. mutans by two mechanisms: synergically at short times and by competition at longer periods.

  11. A Human-Curated Annotation of the Candida albicans Genome

    PubMed Central

    Braun, Burkhard R; van het Hoog, Marco; d'Enfert, Christophe; Martchenko, Mikhail; Dungan, Jan; Kuo, Alan; Inglis, Diane O; Uhl, M. Andrew; Hogues, Hervé; Berriman, Matthew; Lorenz, Michael; Levitin, Anastasia; Oberholzer, Ursula; Bachewich, Catherine; Harcus, Doreen; Marcil, Anne; Dignard, Daniel; Iouk, Tatiana; Zito, Rosa; Frangeul, Lionel; Tekaia, Fredj; Rutherford, Kim; Wang, Edwin; Munro, Carol A; Bates, Steve; Gow, Neil A; Hoyer, Lois L; Köhler, Gerwald; Morschhäuser, Joachim; Newport, George; Znaidi, Sadri; Raymond, Martine; Turcotte, Bernard; Sherlock, Gavin; Costanzo, Maria; Ihmels, Jan; Berman, Judith; Sanglard, Dominique; Agabian, Nina; Mitchell, Aaron P; Johnson, Alexander D; Whiteway, Malcolm; Nantel, André

    2005-01-01

    Recent sequencing and assembly of the genome for the fungal pathogen Candida albicans used simple automated procedures for the identification of putative genes. We have reviewed the entire assembly, both by hand and with additional bioinformatic resources, to accurately map and describe 6,354 genes and to identify 246 genes whose original database entries contained sequencing errors (or possibly mutations) that affect their reading frame. Comparison with other fungal genomes permitted the identification of numerous fungus-specific genes that might be targeted for antifungal therapy. We also observed that, compared to other fungi, the protein-coding sequences in the C. albicans genome are especially rich in short sequence repeats. Finally, our improved annotation permitted a detailed analysis of several multigene families, and comparative genomic studies showed that C. albicans has a far greater catabolic range, encoding respiratory Complex 1, several novel oxidoreductases and ketone body degrading enzymes, malonyl-CoA and enoyl-CoA carriers, several novel amino acid degrading enzymes, a variety of secreted catabolic lipases and proteases, and numerous transporters to assimilate the resulting nutrients. The results of these efforts will ensure that the Candida research community has uniform and comprehensive genomic information for medical research as well as for future diagnostic and therapeutic applications. PMID:16103911

  12. Construction of FLAG tagging vectors for Candida albicans.

    PubMed

    Umeyama, Takashi; Nagai, Yuki; Niimi, Masakazu; Uehara, Yoshimasa

    2002-05-01

    We have constructed three new vectors for Candida albicans (pFLAG-Act1, pFLAG-Mal2, and pFLAG-Met3). The proteins can be expressed as C-terminal FLAG-tagged proteins under the control of different promoters (ACT1, MAL2, and MET3). To confirm the protein expression, we used the Renilla reniformis luciferase and the drug efflux pump Cdr1p of Candida albicans as reporters. The luciferase protein expressed by the MET3 promoter was found to have the strongest activity of the three promoters when cultured in a methionine-depleted synthetic medium. Cdr1p was expressed as a C-terminal FLAG-tagged protein using either these vectors or PCR-mediated integration. The fluconazole resistance was increased by the Cdr1p expression in a CDR1 homozygous disruptant. The expressed proteins were detected by Western blotting using the anti-FLAG antibody. We also constructed a Cdr1p-FLAG expressing strain, in which we directly tagged Cdr1p with FLAG on the genome loci, using a PCR-based integrative marker cassette that was amplified using the pFLAG vector. We then confirmed the protein expression by Western blotting. Thus, these new vectors are useful as C. albicans genetic tools. Copyright 2002 John Wiley & Sons, Ltd.

  13. Galleria mellonella lysozyme induces apoptotic changes in Candida albicans cells.

    PubMed

    Sowa-Jasiłek, Aneta; Zdybicka-Barabas, Agnieszka; Stączek, Sylwia; Wydrych, Jerzy; Skrzypiec, Krzysztof; Mak, Paweł; Deryło, Kamil; Tchórzewski, Marek; Cytryńska, Małgorzata

    2016-12-01

    The greater wax moth Galleria mellonella has been increasingly used as a model host to determine Candida albicans virulence and efficacy of antifungal treatment. The G. mellonella lysozyme, similarly to its human counterpart, is a member of the c-type family of lysozymes that exhibits antibacterial and antifungal activity. However, in contrast to the relatively well explained bactericidal action, the mechanism of fungistatic and/or fungicidal activity of lysozymes is still not clear. In the present study we provide the direct evidences that the G. mellonella lysozyme binds to the protoplasts as well as to the intact C. albicans cells and decreases the survival rate of both these forms in a time-dependent manner. No enzymatic activity of the lysozyme towards typical chitinase and β-glucanase substrates was detected, indicating that hydrolysis of main fungal cell wall components is not responsible for anti-Candida activity of the lysozyme. On the other hand, pre-treatment of cells with tetraethylammonium, a potassium channel blocker, prevented them from the lysozyme action, suggesting that lysozyme acts by induction of programmed cell death. In fact, the C. albicans cells treated with the lysozyme exhibited typical apoptotic features, i.e. loss of mitochondrial membrane potential, phosphatidylserine exposure in the outer leaflet of the cell membrane, as well as chromatin condensation and DNA fragmentation.

  14. Nanocapsules with glycerol monolaurate: Effects on Candida albicans biofilms.

    PubMed

    Lopes, Leonardo Quintana Soares; Santos, Cayane Genro; Vaucher, Rodrigo de Almeida; Raffin, Renata Platcheck; Santos, Roberto Christ Vianna

    2016-08-01

    Candida albicans does not only occur in the free living planktonic form but also grows in surface-attached biofilm communities. Moreover, these biofilms appear to be the most common lifestyle and are involved in the majority of human Candida infections. Nanoparticles can be used as an alternative to conventional antimicrobial agents and can also act as carriers for antibiotics and other drugs. In view of this, the aim of the study was develop, characterize and verify the anti-biofilm potential of GML Nanocapsules against C. albicans. The GML Nanocapsules showed mean diameter of 193.2 nm, polydispersion index of 0.044, zeta potential of -23.3 mV and pH 6.32. The microdilution assay showed MIC of 15.5 μg mL(-1) to GML Nanocapsules and 31.25 μg mL(-1) to GML. The anti-biofilm assay showed the significantly reduction of biomass of C. albicans biofilm treated with GML Nanocapsules while the GML does not exhibit effect. The kinetic assay demonstrated that at 48 h, the GML Nanocapsules reduce 94% of formed biofilm. The positive results suggest the promisor alternative for this public health problem that is biofilm infections.

  15. Rapid flow cytometric susceptibility testing of Candida albicans.

    PubMed Central

    Ramani, R; Ramani, A; Wong, S J

    1997-01-01

    A rapid flow cytometric assay for in vitro antifungal drug susceptibility testing was developed by adapting the proposed reference method for broth macrodilution testing of yeasts. Membrane permeability changes caused by the antifungal agent were measured by flow cytometry using propidium iodide, a nucleic acid-binding fluorochrome largely excluded by the intact cell membrane. We determined the in vitro susceptibility of 31 Candida albicans isolates and two quality control strains (Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258) to amphotericin B and fluconazole. Amphotericin B MICs ranged from 0.03 to 2.0 microg/ml, while fluconazole MICs ranged from 0.125 to 128 microg/ml. This method results in clear-cut endpoints that were reproducible. Four-hour incubation was required for fluconazole, whereas a 2-h incubation was sufficient for amphotericin B to provide MICs comparable to the reference macrodilution method developed by the National Committee for Clinical Laboratory Standards Subcommittee on Antifungal Susceptibility Tests. Results of these studies show that flow cytometry provides a rapid and sensitive in vitro method for antifungal susceptibility testing of C. albicans. PMID:9276410

  16. Polyketide Glycosides from Bionectria ochroleuca Inhibit Candida albicans Biofilm Formation

    PubMed Central

    2015-01-01

    One of the challenges presented by Candida infections is that many of the isolates encountered in the clinic produce biofilms, which can decrease these pathogens’ susceptibilities to standard-of-care antibiotic therapies. Inhibitors of fungal biofilm formation offer a potential solution to counteracting some of the problems associated with Candida infections. A screening campaign utilizing samples from our fungal extract library revealed that a Bionectria ochroleuca isolate cultured on Cheerios breakfast cereal produced metabolites that blocked the in vitro formation of Candida albicans biofilms. A scale-up culture of the fungus was undertaken using mycobags (also known as mushroom bags or spawn bags), which afforded four known [TMC-151s C–F (1–4)] and three new [bionectriols B–D (5–7)] polyketide glycosides. All seven metabolites exhibited potent biofilm inhibition against C. albicans SC5314, as well as exerted synergistic antifungal activities in combination with amphotericin B. In this report, we describe the structure determination of the new metabolites, as well as compare the secondary metabolome profiles of fungi grown in flasks and mycobags. These studies demonstrate that mycobags offer a useful alternative to flask-based cultures for the preparative production of fungal secondary metabolites. PMID:25302529

  17. Morphogenesis-independent regulation of actin transcript levels in the pathogenic yeast Candida albicans.

    PubMed

    Delbrück, S; Ernst, J F

    1993-11-01

    The transcript level of the Candida albicans ACT1 gene (encoding actin) is strongly regulated during induction of hyphal morphogenesis. ACT1 mRNA declines rapidly during starvation pretreatment and quickly recovers in media inducing morphogenesis. The C. albicans URA3 and LEU2 mRNAs, as well as an ACT1 promoter/LAC4 fusion, are regulated similarly. The regulation of ACT1/LAC4 and unaltered mRNA stabilities suggest transcriptional regulation during morphogenesis. However, by individually testing morphogenesis induction parameters, it is shown that starvation and growth phase, but not hyphal formation, are responsible for ACT1 transcript regulation; this conclusion is confirmed by analyses of morphological mutants and by inhibition of hyphal development. Thus, the specific morphogenesis-induction conditions, but not morphogenesis per se, affect transcript levels in C. albicans.

  18. In vitro antifungal and antibiofilm activities of halogenated quinoline analogues against Candida albicans and Cryptococcus neoformans.

    PubMed

    Zuo, Ran; Garrison, Aaron T; Basak, Akash; Zhang, Peilan; Huigens, Robert W; Ding, Yousong

    2016-08-01

    With the increasing prevalence of fungal infections coupled with emerging drug resistance, there is an urgent need for new and effective antifungal agents. Here we report the antifungal activities of 19 diverse halogenated quinoline (HQ) small molecules against Candida albicans and Cryptococcus neoformans. Four HQ analogues inhibited C. albicans growth with a minimum inhibitory concentration (MIC) of 100 nM, whilst 16 analogues effectively inhibited C. neoformans at MICs of 50-780 nM. Remarkably, two HQ analogues eradicated mature C. albicans and C. neoformans biofilms [minimum biofilm eradication concentration (MBEC) = 6.25-62.5 µM]. Several active HQs were found to penetrate into fungal cells, whilst one inactive analogue was unable to, suggesting that HQs elicit their antifungal activities through an intracellular mode of action. HQs are a promising class of small molecules that may be useful in future antifungal treatments.

  19. Commensal Protection of Staphylococcus aureus against Antimicrobials by Candida albicans Biofilm Matrix

    PubMed Central

    Kong, Eric F.; Tsui, Christina; Kucharíková, Sona; Andes, David

    2016-01-01

    ABSTRACT Biofilm-associated polymicrobial infections, particularly those involving fungi and bacteria, are responsible for significant morbidity and mortality and tend to be challenging to treat. Candida albicans and Staphylococcus aureus specifically are considered leading opportunistic fungal and bacterial pathogens, respectively, mainly due to their ability to form biofilms on catheters and indwelling medical devices. However, the impact of mixed-species biofilm growth on therapy remains largely understudied. In this study, we investigated the influence of C. albicans secreted cell wall polysaccharides on the response of S. aureus to antibacterial agents in biofilm. Results demonstrated significantly enhanced tolerance for S. aureus to drugs in the presence of C. albicans or its secreted cell wall polysaccharide material. Fluorescence confocal time-lapse microscopy revealed impairment of drug diffusion through the mixed biofilm matrix. Using C. albicans mutant strains with modulated cell wall polysaccharide expression, exogenous supplementation, and enzymatic degradation, the C. albicans-secreted β-1,3-glucan cell wall component was identified as the key matrix constituent providing the bacteria with enhanced drug tolerance. Further, antibody labeling demonstrated rapid coating of the bacteria by the C. albicans matrix material. Importantly, via its effect on the fungal biofilm matrix, the antifungal caspofungin sensitized the bacteria to the drugs. Understanding such symbiotic interactions with clinical relevance between microbial species in biofilms will greatly aid in overcoming the limitations of current therapies and in defining potential new targets for treating polymicrobial infections. PMID:27729510

  20. Opportunistic pathogen Candida albicans elicits a temporal response in primary human mast cells.

    PubMed

    Lopes, José Pedro; Stylianou, Marios; Nilsson, Gunnar; Urban, Constantin F

    2015-07-20

    Immunosuppressed patients are frequently afflicted with severe mycoses caused by opportunistic fungal pathogens. Besides being a commensal, colonizing predominantly skin and mucosal surfaces, Candida albicans is the most common human fungal pathogen. Mast cells are present in tissues prone to fungal colonization being expectedly among the first immune cells to get into contact with C. albicans. However, mast cell-fungus interaction remains a neglected area of study. Here we show that human mast cells mounted specific responses towards C. albicans. Collectively, mast cell responses included the launch of initial, intermediate and late phase components determined by the secretion of granular proteins and cytokines. Initially mast cells reduced fungal viability and occasionally internalized yeasts. C. albicans could evade ingestion by intracellular growth leading to cellular death. Furthermore, secreted factors in the supernatants of infected cells recruited neutrophils, but not monocytes. Late stages were marked by the release of cytokines that are known to be anti-inflammatory suggesting a modulation of initial responses. C. albicans-infected mast cells formed extracellular DNA traps, which ensnared but did not kill the fungus. Our results suggest that mast cells serve as tissue sentinels modulating antifungal immune responses during C. albicans infection. Consequently, these findings open new doors for understanding fungal pathogenicity.

  1. Candida albicans VPS1 contributes to protease secretion, filamentation, and biofilm formation.

    PubMed

    Bernardo, Stella M; Khalique, Zachary; Kot, John; Jones, Jason K; Lee, Samuel A

    2008-06-01

    To investigate the pre-vacuolar secretory pathway in Candida albicans, we cloned and analyzed the C. albicans homolog of the Saccharomyces cerevisiae vacuolar protein sorting gene VPS1. C. albicans VPS1 encodes a predicted 694-aa dynamin-like GTPase that is 73.3% similar to S. cerevisiae Vps1p. Plasmids bearing C. albicans VPS1 complemented the temperature-sensitive growth, abnormal class F vacuolar morphology, and carboxypeptidase missorting of a S. cerevisiae vps1 null mutant. To study VPS1 function in C. albicans, a conditional mutant strain (tetR-VPS1) was generated by deleting the first allele of VPS1 and placing the second allele under control of a tetracycline-regulatable promoter. With doxycycline, the tetR-VPS1 mutant was hyper-susceptible to sub-inhibitory concentrations of fluconazole, but not amphotericin B, 5-fluorocytosine, or non-specific osmotic stresses. The repressed tetR-VPS1 mutant was defective in filamentation and secreted less extracellular protease activity. Biofilm production and filamentation within the biofilm were markedly reduced. These results suggest that C. albicans VPS1 has a key role in several important virulence-related phenotypes.

  2. Spaceflight Enhances Cell Aggregation and Random Budding in Candida albicans

    PubMed Central

    Woolley, Christine M.; Barrila, Jennifer; Buchanan, Kent; McCracken, James; Inglis, Diane O.; Searles, Stephen C.; Nelman-Gonzalez, Mayra A.; Ott, C. Mark; Wilson, James W.; Pierson, Duane L.; Stefanyshyn-Piper, Heidemarie M.; Hyman, Linda E.; Nickerson, Cheryl A.

    2013-01-01

    This study presents the first global transcriptional profiling and phenotypic characterization of the major human opportunistic fungal pathogen, Candida albicans, grown in spaceflight conditions. Microarray analysis revealed that C. albicans subjected to short-term spaceflight culture differentially regulated 452 genes compared to synchronous ground controls, which represented 8.3% of the analyzed ORFs. Spaceflight-cultured C. albicans–induced genes involved in cell aggregation (similar to flocculation), which was validated by microscopic and flow cytometry analysis. We also observed enhanced random budding of spaceflight-cultured cells as opposed to bipolar budding patterns for ground samples, in accordance with the gene expression data. Furthermore, genes involved in antifungal agent and stress resistance were differentially regulated in spaceflight, including induction of ABC transporters and members of the major facilitator family, downregulation of ergosterol-encoding genes, and upregulation of genes involved in oxidative stress resistance. Finally, downregulation of genes involved in actin cytoskeleton was observed. Interestingly, the transcriptional regulator Cap1 and over 30% of the Cap1 regulon was differentially expressed in spaceflight-cultured C. albicans. A potential role for Cap1 in the spaceflight response of C. albicans is suggested, as this regulator is involved in random budding, cell aggregation, and oxidative stress resistance; all related to observed spaceflight-associated changes of C. albicans. While culture of C. albicans in microgravity potentiates a global change in gene expression that could induce a virulence-related phenotype, no increased virulence in a murine intraperitoneal (i.p.) infection model was observed under the conditions of this study. Collectively, our data represent an important basis for the assessment of the risk that commensal flora could play during human spaceflight missions. Furthermore, since the low fluid

  3. Factors Supporting Cysteine Tolerance and Sulfite Production in Candida albicans

    PubMed Central

    Hennicke, Florian; Grumbt, Maria; Lermann, Ulrich; Ueberschaar, Nico; Palige, Katja; Böttcher, Bettina; Jacobsen, Ilse D.; Staib, Claudia; Morschhäuser, Joachim; Monod, Michel; Hube, Bernhard; Hertweck, Christian

    2013-01-01

    The amino acid cysteine has long been known to be toxic at elevated levels for bacteria, fungi, and humans. However, mechanisms of cysteine tolerance in microbes remain largely obscure. Here we show that the human pathogenic yeast Candida albicans excretes sulfite when confronted with increasing cysteine concentrations. Mutant construction and phenotypic analysis revealed that sulfite formation from cysteine in C. albicans relies on cysteine dioxygenase Cdg1, an enzyme with similar functions in humans. Environmental cysteine induced not only the expression of the CDG1 gene in C. albicans, but also the expression of SSU1, encoding a putative sulfite efflux pump. Accordingly, the deletion of SSU1 resulted in enhanced sensitivity of the fungal cells to both cysteine and sulfite. To study the regulation of sulfite/cysteine tolerance in more detail, we screened a C. albicans library of transcription factor mutants in the presence of sulfite. This approach and subsequent independent mutant analysis identified the zinc cluster transcription factor Zcf2 to govern sulfite/cysteine tolerance, as well as cysteine-inducible SSU1 and CDG1 gene expression. cdg1Δ and ssu1Δ mutants displayed reduced hypha formation in the presence of cysteine, indicating a possible role of the newly proposed mechanisms of cysteine tolerance and sulfite secretion in the pathogenicity of C. albicans. Moreover, cdg1Δ mutants induced delayed mortality in a mouse model of disseminated infection. Since sulfite is toxic and a potent reducing agent, its production by C. albicans suggests diverse roles during host adaptation and pathogenicity. PMID:23417561

  4. Acid production by oral strains of Candida albicans and lactobacilli.

    PubMed

    Klinke, T; Kneist, S; de Soet, J J; Kuhlisch, E; Mauersberger, S; Forster, A; Klimm, W

    2009-01-01

    Both Candida albicans and lactobacilli are common colonizers of carious lesions in children and adolescents. The purpose of this study is to compare the velocity of acid production between C. albicans and several Lactobacillus species at different pH levels and concentrations of glucose. Washed, pure resting-cell suspensions were obtained by culturing a total of 28 oral isolates comprising the species C. albicans, Lactobacillus rhamnosus, Lactobacillus paracasei paracasei, Lactobacillus paracasei tolerans and Lactobacillus delbrueckii lactis. Acid production from glucose was determined at a constant pH of 7.0, 5.5, 5.0 and 4.0 by repeated titrations with NaOH in an automated pH-stat system. Acid formation rates of yeast and lactobacilli proved to be similar at both neutral and low pH, while in a moderately acidic environment C. albicans produced less acid than the lactobacilli. Ion chromatographic analysis of the cell-free medium after titration revealed pyruvate to be the predominant organic acid anion secreted by C. albicans. The proportion of organic acids to overall acid production by the yeast was below 10% at neutral conditions, in contrast to 42-66% at pH 4.0. Compared to lactobacilli, yeast required a concentration of glucose that was about 50 times higher to allow acid production at half the maximum speed. Considering the clinical data in the literature about the frequency and proportions of microorganisms present in early childhood caries lesions, the contribution of oral lactobacilli as well as C. albicans to overall microbial acid formation appears to be important.

  5. Evaluation of a rapid immunochromatographic assay for identification of Candida albicans and Candida dubliniensis.

    PubMed

    Marot-Leblond, Agnes; Grimaud, Linda; David, Sandrine; Sullivan, Derek J; Coleman, David C; Ponton, Jose; Robert, Raymond

    2004-11-01

    Candida dubliniensis was first established as a novel yeast species in 1995. It is particularly associated with recurrent episodes of oral candidosis in human immunodeficiency virus (HIV)-infected patients, but it has also been detected at other anatomical sites and at a low incidence level in non-HIV-infected patients. It shares so many phenotypic characteristics with C. albicans that it is easily misidentified as such. No rapid, simple, and commercial test that allows differentiation between C. dubliniensis and C. albicans has been developed, until now. Accurate species identification requires the use of genotype-based techniques that are not routinely available in most clinical microbiology diagnostic laboratories. The present study was designed to evaluate the efficiency of a new test (the immunochromatographic membrane [ICM] albi-dubli test; SR2B, Avrille, France) to differentiate between C. albicans and C. dubliniensis. The organisms evaluated were strains whose identities had previously been confirmed by PCR tests and freshly isolated clinical strains and included 58 C. albicans isolates, 60 C. dubliniensis isolates, and 82 isolates belonging to other species of yeast. The ICM albi-dubli test is based on the principle of immunochromatographic analysis and involves the use of two distinct monoclonal antibodies that recognize two unrelated epitopes expressed by both species or specific to only one species. The assay requires no complex instrumentation for analysis and can be recommended for routine use in clinical microbiology laboratories. Results are obtained within 2 h and 30 min and are easy to interpret. This evaluation demonstrated the good performance of this immunochromatographic test for C. albicans and C. dubliniensis isolated on Sabouraud dextrose agar, CHOROMagar Candida, and CandidaSelect, with sensitivities and specificities ranging from 93.1 to 100%. These parameters decreased, however, to 91.4% when the test was performed with yeast isolated

  6. Candida species biofilm and Candida albicans ALS3 polymorphisms in clinical isolates.

    PubMed

    Bruder-Nascimento, Ariane; Camargo, Carlos Henrique; Mondelli, Alessandro Lia; Sugizaki, Maria Fátima; Sadatsune, Terue; Bagagli, Eduardo

    2014-01-01

    Over the last decades, there have been important changes in the epidemiology of Candida infections. In recent years, Candida species have emerged as important causes of invasive infections mainly among immunocompromised patients. This study analyzed Candida spp. isolates and compared the frequency and biofilm production of different species among the different sources of isolation: blood, urine, vulvovaginal secretions and peritoneal dialysis fluid. Biofilm production was quantified in 327 Candida isolates obtained from patients attended at a Brazilian tertiary public hospital (Botucatu, Sao Paulo). C. albicans ALS3 gene polymorphism was also evaluated by determining the number of repeated motifs in the central domain. Of the 198 total biofilm-positive isolates, 72 and 126 were considered as low and high biofilm producers, respectively. Biofilm production by C. albicans was significantly lower than that by non-albicans isolates and was most frequently observed in C. tropicalis. Biofilm production was more frequent among bloodstream isolates than other clinical sources, in urine, the isolates displayed a peculiar distribution by presenting two distinct peaks, one containing biofilm-negative isolates and the other containing isolates with intense biofilm production. The numbers of tandem-repeat copies per allele were not associated with biofilm production, suggesting the evolvement of other genetic determinants.

  7. O-Mannosylation in Candida albicans Enables Development of Interkingdom Biofilm Communities

    PubMed Central

    Dutton, Lindsay C.; Nobbs, Angela H.; Jepson, Katy; Jepson, Mark A.; Vickerman, M. Margaret; Aqeel Alawfi, Sami; Munro, Carol A.; Lamont, Richard J.; Jenkinson, Howard F.

    2014-01-01

    ABSTRACT Candida albicans is a fungus that colonizes oral cavity surfaces, the gut, and the genital tract. Streptococcus gordonii is a ubiquitous oral bacterium that has been shown to form biofilm communities with C. albicans. Formation of dual-species S. gordonii-C. albicans biofilm communities involves interaction of the S. gordonii SspB protein with the Als3 protein on the hyphal filament surface of C. albicans. Mannoproteins comprise a major component of the C. albicans cell wall, and in this study we sought to determine if mannosylation in cell wall biogenesis of C. albicans was necessary for hyphal adhesin functions associated with interkingdom biofilm development. A C. albicans mnt1Δ mnt2Δ mutant, with deleted α-1,2-mannosyltransferase genes and thus defective in O-mannosylation, was abrogated in biofilm formation under various growth conditions and produced hyphal filaments that were not recognized by S. gordonii. Cell wall proteomes of hypha-forming mnt1Δ mnt2Δ mutant cells showed growth medium-dependent alterations, compared to findings for the wild type, in a range of protein components, including Als1, Als3, Rbt1, Scw1, and Sap9. Hyphal filaments formed by mnt1Δ mnt2Δ mutant cells, unlike wild-type hyphae, did not interact with C. albicans Als3 or Hwp1 partner cell wall proteins or with S. gordonii SspB partner adhesin, suggesting defective functionality of adhesins on the mnt1Δ mnt2Δ mutant. These observations imply that early stage O-mannosylation is critical for activation of hyphal adhesin functions required for biofilm formation, recognition by bacteria such as S. gordonii, and microbial community development. PMID:24736223

  8. Deltamethrin Increases Candida albicans infection susceptibility in mice.

    PubMed

    Rehman, H; Mohan, A; Tabassum, H; Ahmad, F; Rahman, S; Parvez, S; Raisuddin, S

    2011-05-01

    Deltamethrin, an alpha-cyano type II synthetic pyrethroid insecticide, is used to control a wide range of insects on a variety of crops and vectors of diseases. Deltamethrin has been previously reported for its immunotoxic effects and therefore its exposure may affect the host resistance to infection and tumour challenge. Effect of exposure of deltamethrin on host resistance to Candida albicans infection was examined in Swiss albino mice. The objective of this study was to investigate the modulatory action of deltamethrin in C. albicans infected mice. The dose of deltamethrin was initially tested and selected from our previous study (18 mg/kg). Percentage of infection in deltamethrin treated animals increased faster when compared to that of the controls. Deltamethrin exposure along with C. albicans infection caused alteration of humoral immune response. The number of colony forming unit in liver and spleen were also found to be significantly increased in the treated group. The results from our present study suggest that deltamethrin exhibits an immunosuppressive effect and has a negative impact on host resistance to C. albicans infection. © 2011 The Authors. Scandinavian Journal of Immunology © 2011 Blackwell Publishing Ltd.

  9. Lipidomics and in Vitro Azole Resistance in Candida albicans

    PubMed Central

    Singh, Ashutosh; Mahto, Kaushal Kumar

    2013-01-01

    Abstract We have shown earlier that fluconazole (FLC) stress induces global changes in the lipidome of Candida albicans in clinically adapted isolates. However, several laboratories have developed adapted in vitro FLC resistant strains of C. albicans to study azole resistance mechanisms. This study aimed to identify the lipid changes associated with FLC resistance in these in vitro adapted isolates. Using comparative lipidomics and principal component and discriminant analyses, we observed gradual changes in several lipid classes and molecular species upon FLC exposure of in vitro resistant C. albicans strains. Although the lipid imprint of FLC in vitro resistant isolates was very distinct from that of clinical isolates of C. albicans, the overall changes in lipid class compositions were similar in both cases. For example, an increased sterol content and depleted sphingolipid levels were the salient features of FLC resistance in both conditions. Taken together, it appears that the overall cellular lipid homeostasis is a critical factor in the observed FLC resistance and in handling FLC stress in both clinical and laboratory situations. The new observations reported herein have implications for more efficacious antifungal drug development as well as understanding host–infectious agent interactions in postgenomics microbiology practice. PMID:23374108

  10. Zebrafish Egg Infection Model for Studying Candida albicans Adhesion Factors

    PubMed Central

    Chen, Yin-Zhi; Yang, Yun-Liang; Chu, Wen-Li; You, May-Su; Lo, Hsiu-Jung

    2015-01-01

    Disseminated candidiasis is associated with 30–40% mortality in severely immunocompromised patients. Among the causal agents, Candida albicans is the dominant one. Various animal models have been developed for investigating gene functions in C. albicans. Zebrafish injection models have increasingly been applied in elucidating C. albicans pathogenesis because of the conserved immunity, prolific fecundity of the zebrafish and the low costs of care systems. In this study, we established a simple, noninvasive zebrafish egg bath infection model, defined its optimal conditions, and evaluated the model with various C. albicans mutant strains. The deletion of SAP6 did not have significant effect on the virulence. By contrast, the deletion of BCR1, CPH1, EFG1, or TEC1 significantly reduced the virulence under current conditions. Furthermore, all embryos survived when co-incubated with bcr1/bcr1, cph1/cph1 efg1/efg1, efg1/efg1, or tec1/tec1 mutant cells. The results indicated that our novel zebrafish model is time-saving and cost effective. PMID:26569623

  11. Quantitative relationships of Candida albicans infections and dressing patterns in Nigerian women.

    PubMed Central

    Elegbe, I A; Elegbe, I

    1983-01-01

    Candida albicans colony counts were far higher in patients with vaginitis wearing tight fitting clothing than in patients wearing loose fitting clothing. In Ile-Ife, Nigeria, tight fitting dresses, woolen and corduroy jeans, coupled with nylon underwear, appear to create an environment favorable to Candida albicans colonization. PMID:6338749

  12. Quantitative relationships of Candida albicans infections and dressing patterns in Nigerian women.

    PubMed

    Elegbe, I A; Elegbe, I

    1983-04-01

    Candida albicans colony counts were far higher in patients with vaginitis wearing tight fitting clothing than in patients wearing loose fitting clothing. In Ile-Ife, Nigeria, tight fitting dresses, woolen and corduroy jeans, coupled with nylon underwear, appear to create an environment favorable to Candida albicans colonization.

  13. Effect of 5-aminolevulinic acid photodynamic therapy on Candida albicans biofilms: An in vitro study.

    PubMed

    Shi, Hang; Li, Jiyang; Zhang, Hui; Zhang, Jie; Sun, Hongying

    2016-09-01

    In this study, the photoinactivation of 5-aminolevulinic acid (ALA) has been investigated on Candida albicans biofilms in vitro. After culture and proliferation of Candida albicans biofilms in vitro, the metabolic activity was confirmed using XTT reduction assay. Then, the suitable incubation time and concentration of ALA were determined by measuring PpIX accumulation quantities. Photosensitivity of the biofilms treated with ALA solution was studied in optical doses of 50, 100, 200 and 300J/cm(2) while light irradiation was applied by a red light semiconductor. Finally, rapid immunofluorescence staining method using the LIVE/DEAD FungaLight Yeast Viability Kit and XTT assay were conducted to visualize and quantify the antifungal effect of ALA-PDT on Candida albicans biofilms. A 5h incubation time and 15mM ALA concentration were determined for this study. Photoinactivation of ALA-PDT on Candida albicans biofilms showed a significant increase of protoporphyrin IX (PpIX) in the biofilms. The metabolic activity of Candida albicans biofilms tread with ALA-PDT confirmed the inhibition efficacy compared with control groups. Upon radiation at 300J/cm(2), cells in Candida albicans biofilms were 74.45% inhibited. PpIX can be absorbed in biofilm-grown Candida albicans in vitro and under appropriate parameters, photochemistry can be triggered by light in combination with ALA and inhibits Candida albicans biofilms effectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Adaptation of Candida albicans to commensalism in the gut.

    PubMed

    Prieto, Daniel; Correia, Inês; Pla, Jesús; Román, Elvira

    2016-01-01

    Candida albicans is a common resident of the oral cavity, GI tract and vagina in healthy humans where it establishes a commensal relationship with the host. Colonization of the gut, which is an important niche for the microbe, may lead to systemic dissemination and disease upon alteration of host defences. Understanding the mechanisms responsible for the adaptation of C. albicans to the gut is therefore important for the design of new ways of combating fungal diseases. In this review we discuss the available models to study commensalism of this yeast, the main mechanisms controlling the establishment of the fungus, such as microbiota, mucus layer and antimicrobial peptides, and the gene regulatory circuits that ensure its survival in this niche.

  15. An immunological link between Candida albicans colonization and Crohn's disease.

    PubMed

    Gerard, Romain; Sendid, Boualem; Colombel, Jean-Frederic; Poulain, Daniel; Jouault, Thierry

    2015-06-01

    The etiology of Crohn's disease (CD), an autoimmune, inflammatory bowel disease (IBD) which affects approximately one million people in Europe, is still unclear. Nevertheless, it is widely accepted that CD could result from an inappropriate inflammatory response to intestinal microorganisms in a genetically susceptible host. Most studies to date have concerned the involvement of bacteria in disease progression. In addition to bacteria, there appears to be a possible link between the commensal yeast Candida albicans and disease development. In this review, in an attempt to link the gut colonization process and the development of CD, we describe the different pathways that are involved in the progression of CD and in the host response to C. albicans, making the yeast a possible initiator of the inflammatory process observed in this IBD.

  16. Molecular methods for strain typing of Candida albicans: a review.

    PubMed

    Saghrouni, F; Ben Abdeljelil, J; Boukadida, J; Ben Said, M

    2013-06-01

    Candida albicans is one of the most medically important fungi because of its high frequency as a commensal and pathogenic microorganism causing superficial as well as invasive infections. Strain typing and delineation of the species are essential for understanding its biology, epidemiology and population structure. A wide range of molecular techniques have been used for this purpose including non-DNA-based methods (multi-locus enzyme electrophoresis), conventional DNA-based methods (electrophoretic karyotyping, random amplified polymorphic DNA, amplified fragment length polymorphism, restriction enzyme analysis with and without hybridization, rep-PCR) and DNA-based methods called exact typing methods because they generate unambiguous and highly reproducible typing data (including microsatellite length polymorphism and multi-locus sequence typing). In this review, the main molecular methods used for C. albicans strain typing are summarized, and their advantages and limitations are discussed with regard to their discriminatory power, reproducibility, cost and ease of performance.

  17. Recent advances on Candida albicans biology and virulence

    PubMed Central

    Sellam, Adnane; Whiteway, Malcolm

    2016-01-01

    Candida albicans is an important human fungal pathogen, in terms of both its clinical significance and its use as an experimental model for scientific investigation. Although this opportunistic pathogen is a natural component of the human flora, it can cause life-threatening infections in immunosuppressed patients. There are currently a limited number of antifungal molecules and drug targets, and increasing resistance to the front-line therapeutics, demonstrating a clear need for new antifungal drugs. Understanding the biology of this pathogen is an important prerequisite for identifying new drug targets for antifungal therapeutics. In this review, we highlight some recent developments that help us to understand how virulence traits are regulated at the molecular level, in addition to technical advances that improve the ability of genome editing in C. albicans. PMID:27853524

  18. Glutathione protects Candida albicans against horseradish volatile oil.

    PubMed

    Bertóti, Regina; Vasas, Gábor; Gonda, Sándor; Nguyen, Nhat Minh; Szőke, Éva; Jakab, Ágnes; Pócsi, István; Emri, Tamás

    2016-10-01

    Horseradish essential oil (HREO; a natural mixture of different isothiocyanates) had strong fungicide effect against Candida albicans both in volatile and liquid phase. In liquid phase this antifungal effect was more significant than those of its main components allyl, and 2-phenylethyl isothiocyanate. HREO, at sublethal concentration, induced oxidative stress which was characterized with elevated superoxide content and up-regulated specific glutathione reductase, glutathione peroxidase, catalase and superoxide dismutase activities. Induction of specific glutathione S-transferase activities as marker of glutathione (GSH) dependent detoxification was also observed. At higher concentration, HREO depleted the GSH pool, increased heavily the superoxide production and killed the cells rapidly. HREO and the GSH pool depleting agent, 1-chlore-2,4-dinitrobenzene showed strong synergism when they were applied together to kill C. albicans cells. Based on all these, we assume that GSH metabolism protects fungi against isothiocyanates. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Recent advances on Candida albicans biology and virulence.

    PubMed

    Sellam, Adnane; Whiteway, Malcolm

    2016-01-01

    Candida albicans is an important human fungal pathogen, in terms of both its clinical significance and its use as an experimental model for scientific investigation. Although this opportunistic pathogen is a natural component of the human flora, it can cause life-threatening infections in immunosuppressed patients. There are currently a limited number of antifungal molecules and drug targets, and increasing resistance to the front-line therapeutics, demonstrating a clear need for new antifungal drugs. Understanding the biology of this pathogen is an important prerequisite for identifying new drug targets for antifungal therapeutics. In this review, we highlight some recent developments that help us to understand how virulence traits are regulated at the molecular level, in addition to technical advances that improve the ability of genome editing in C. albicans.

  20. [The effects of an aroma candy on oral Candida albicans colony-forming units (CFU) and oral hygiene states in healthy elderly carrying Candida albicans].

    PubMed

    Suzuki, Motofumi; Hayama, Kazumi; Takahashi, Miki; Ezawa, Kunio; Yamazaki, Masatoshi; Matsukawa, Taiji; Kishi, Akinobu; Satou, Nobuya; Abe, Shigeru

    2015-01-01

    In a preceding paper, we showed that aroma candy containing oligonol, capric acid, and cinnamon (cassia) powder had potent inhibitory activity against mycelial growth of Candida albicans in vitro and protective activity against murine oral candidiasis. In order to assess the effects of this candy (the test candy) on oral C. albicans colony-forming units (CFU) and oral hygiene states, a placebo-controlled double-blind crossover comparative study was performed. Twenty subjects were divided into two groups. One group ingested the test candy in the first 7 days followed by 2 weeks washing-off period, then ingested the placebo candy (control candy) for 7 days. The other group was vice versa. C. albicans CFU in all oral rinse samples from the subjects before and after 7 days ingestion of candy was measured. The degree of oral malodor in all subjects was monitored using a portable measuring instrument. The results showed no statistically significant difference between test-candy group and placebo group for C. albicans CFU. However, C. albicans CFU in test-candy group with>4,000 CFUs was significantly decreased after 7 days ingestion of test-candy (p<0.05). Scores of oral malodor in the test-candy group was significantly decreased after 7 days ingestion of test-candy (p<0.05). A questionnaire survey of oral hygiene states indicated that in the test-candy group, oral malodor, glutinous feeling, and refreshing feeling significantly improved in comparison with control-candy group (p<0.05). Our study suggests that the aroma candy is effective in oral health care of elderly carrying C. albicans.

  1. Candida albicans biofilms: building a heterogeneous, drug-tolerant environment.

    PubMed

    Bonhomme, Julie; d'Enfert, Christophe

    2013-08-01

    Fungi are able to form biofilms on medical implants, causing serious infections. A better understanding of fungal biofilm formation is necessary to develop tools for detection or prevention and to identify new antifungal strategies. This review explores recent advances in the characterization at the molecular level of fungal biofilms, especially those formed by the yeast Candida albicans: the identification of complex transcriptional networks that control their formation; the pivotal role of the extracellular matrix in biofilm antifungal tolerance; and the knowledge gained on the physiology of biofilm cells and heterogeneity within these communities. These findings may help develop new, targeted therapeutic strategies.

  2. Variation of electrophoretic karyotypes among clinical isolates of Candida albicans.

    PubMed Central

    Merz, W G; Connelly, C; Hieter, P

    1988-01-01

    Orthogonal-field-alternation gel electrophoresis was used to compare clinical isolates of Candida albicans by resolving chromosome-sized DNA molecules into an electrophoretic karyotype. Seven to nine bands were observed among isolates recovered from 17 patients. In addition, 14 distinct electrophoretic patterns were noted among the isolates from these patients. In a given individual, isolates were likely to have identical electrophoretic patterns. Therefore, the electrophoretic karyotype patterns demonstrated by orthogonal-field-alternation gel electrophoresis can be used to designate a strain for epidemiologic studies. Images PMID:3290238

  3. Detection of myosin immunoanalogue in the yeast Candida albicans.

    PubMed

    Ghazali, M; Rodier, M H; el Moudni, B; Quellard, N; Jacquemin, J L

    1995-06-01

    Detection and localization of myosin immunoanalogue protein in the yeast Candida albicans were achieved by immunoblotting, indirect immunofluorescence assay, and immunoelectron microscopy. A polypeptide with an M(r) about 110,000, from cytosolic extract and insoluble fraction in the corresponding membrane pellet, was reacted with polyclonal and monoclonal antibodies raised against vertebrate muscle myosin. This protein was located by immunofluorescence and immunoelectron microscopy in the cell cortex along the plasmalemma, in the cytoplasm, and in the septum corresponding to bud scar region situated between the yeast-mother cell and the bud.

  4. Candida detection system (CAND-TEC) to differentiate between Candida albicans colonization and disease.

    PubMed

    Fung, J C; Donta, S T; Tilton, R C

    1986-10-01

    Eighty-three serum specimens from 24 patients infected with Candida albicans were examined for circulating Candida protein antigens with the Candida Detection System (CAND-TEC; Ramco Laboratories, Inc., Houston, Tex.). The medical records of each patient were reviewed for clinical evidence of Candida colonization or disease, predisposing factors for infection, underlying illness, the presence of a contaminated indwelling venous catheter, intravenous amphotericin B therapy, and outcome. Forty-nine serum specimens with antigen titers of 1:2 or less were obtained either from colonized patients or at a time when disseminated disease was not yet clinically suspected. Except for five specimens from two colonized patients, one with a contaminated arterial line, the other specimens with titers of 1:8 or greater (n = 14) were obtained from patients who had been clinically diagnosed and treated for disseminated candidiasis. Serum specimens with titers of 1:4 were often from patients with deep-seated candidal infection but were not uniformly diagnostic; in this situation additional specimens should be tested for Candida antigen titers. Only 1 of 24 serum specimens from patients with no evidence of C. albicans infection had a Candida protein antigen titer of 1:8. With a 1:8 or greater titer as a criterion for dissemination, the sensitivity of the CAND-TEC system was 71%, with a specificity of 98%. If the 1:8 titer for the colonized patient with a contaminated arterial line is not considered a false-positive result, the CAND-TEC sensitivity was 83%. The latex agglutination assay appears to be a useful, rapid, and noninvasive means of laboratory diagnosis of systemic candidiasis. The recovery of C. albicans from at least three body sites may also be a useful predictor of disseminated disease.

  5. Synergistic Effects and Mechanisms of Budesonide in Combination with Fluconazole against Resistant Candida albicans

    PubMed Central

    Li, Xiuyun; Yu, Cuixiang; Huang, Xin; Sun, Shujuan

    2016-01-01

    Candida albicans is an important opportunistic pathogen, causing both superficial mucosal infections and life-threatening systemic diseases in the clinic. The emergence of drug resistance in Candida albicans has become a noteworthy phenomenon due to the extensive use of antifungal agents and the development of biofilms. This study showed that budesonide potentiates the antifungal effect of fluconazole against fluconazole-resistant Candida albicans strains both in vitro and in vivo. In addition, our results demonstrated, for the first time, that the combination of fluconazole and budesonide can reverse the resistance of Candida albicans by inhibiting the function of drug transporters, reducing the formation of biofilms, promoting apoptosis and inhibiting the activity of extracellular phospholipases. This is the first study implicating the effects and mechanisms of budesonide against Candida albicans alone or in combination with fluconazole, which may ultimately lead to the identification of new potential antifungal targets. PMID:28006028

  6. A Case Report of Penile Infection Caused by Fluconazole- and Terbinafine-Resistant Candida albicans.

    PubMed

    Hu, Yongxuan; Hu, Yanqing; Lu, Yan; Huang, Shiyun; Liu, Kangxing; Han, Xue; Mao, Zuhao; Wu, Zhong; Zhou, Xianyi

    2017-04-01

    Candida albicans is the most common pathogen that causes balanoposthitis. It often causes recurrence of symptoms probably due to its antifungal resistance. A significant number of balanitis Candida albicans isolates are resistant to azole and terbinafine antifungal agents in vitro. However, balanoposthitis caused by fluconazole- and terbinafine-resistant Candida albicans has rarely been reported. Here, we describe a case of a recurrent penile infection caused by fluconazole- and terbinafine-resistant Candida albicans, as well as the treatments administered to this patient. The isolate from the patient was tested for drug susceptibility in vitro. It was sensitive to itraconazole, voriconazole, clotrimazole and amphotericin B, but not to terbinafine and fluconazole. Thus, oral itraconazole was administrated to this patient with resistant Candida albicans penile infection. The symptoms were improved, and mycological examination result was negative. Follow-up treatment of this patient for 3 months showed no recurrence.

  7. Liquid and vapour-phase antifungal activities of essential oils against Candida albicans and non-albicans Candida.

    PubMed

    Mandras, Narcisa; Nostro, Antonia; Roana, Janira; Scalas, Daniela; Banche, Giuliana; Ghisetti, Valeria; Del Re, Simonetta; Fucale, Giacomo; Cuffini, Anna Maria; Tullio, Vivian

    2016-08-30

    The management of Candida infections faces many problems, such as a limited number of antifungal drugs, toxicity, resistance of Candida to commonly antifungal drugs, relapse of Candida infections, and the high cost of antifungal drugs. Though azole antifungal agents and derivatives continue to dominate as drugs of choice against Candida infections, there are many available data referring to the anticandidal activity of essential oils. Since we have previous observed a good antimicrobial activity of some essential oils against filamentous fungi, the aim of this study was to extend the research to evaluate the activity of the same oils on Candida albicans, C.glabrata and C.tropicalis clinical strains, as well as the effects of related components. Essential oils selection was based both on ethnomedicinal use and on proved antibacterial and/or antifungal activity of some of these oils. Fluconazole and voriconazole were used as reference drugs. The minimum inhibitory concentration (MIC) and the minimal fungicidal concentration (MFC) of essential oils (thyme red, fennel, clove, pine, sage, lemon balm, and lavender) and their major components were investigated by the broth microdilution method (BM) and the vapour contact assay (VC). Using BM, pine oil showed the best activity against all strains tested, though C.albicans was more susceptible than C.glabrata and C.tropicalis (MIC50-MIC90 = 0.06 %, v/v). On the contrary, sage oil displayed a weak activity (MIC50-MIC90 = 1 %, v/v). Thyme red oil (MIC50-MIC90 ≤ 0.0038 %, v/v for C.albicans and C.tropicalis, and 0.0078- < 0.015 %, v/v for C.glabrata), followed by lemon balm, lavender and sage were the most effective by VC. Carvacrol and thymol showed the highest activity, whereas linalyl acetate showed the lowest activity both by two methods. α-pinene displayed a better activity by BM than VC. Results show a good activity of essential oils, mainly thymus red and pine oils, and their components carvacrol

  8. Fungicidal effect of photodynamic therapy against fluconazole-resistant Candida albicans and Candida glabrata.

    PubMed

    Dovigo, Lívia Nordi; Pavarina, Ana Cláudia; Mima, Ewerton Garcia de Oliveira; Giampaolo, Eunice Teresinha; Vergani, Carlos Eduardo; Bagnato, Vanderlei Salvador

    2011-03-01

    Although photodynamic therapy (PDT) has shown great promise for the inactivation of Candida species, its effectiveness against azole-resistant pathogens remains poorly documented. This in vitro study describes the association of Photogem® (Photogem, Moscow, Russia) with LED (light emitting diode) light for the photoinactivation of fluconazole-resistant (FR) and American Type Culture Collection (ATCC) strains of Candida albicans and Candida glabrata. Suspensions of each Candida strain were treated with five Photogem® concentrations and exposed to four LED light fluences (14, 24, 34 or 50 min of illumination). After incubation (48 h at 37 °C), colonies were counted (CFU ml(-1)). Single-species biofilms were generated on cellulose membrane filters, treated with 25.0 mg l(-1) of Photogem® and illuminated at 37.5 J cm(-2). The biofilms were then disrupted and the viable yeast cells present were determined. Planktonic suspensions of FR strains were effectively killed after PDT. It was observed that the fungicidal effect of PDT was strain-dependent. Significant decreases in biofilm viability were observed for three strains of C. albicans and for two strains of C. glabrata. The results of this investigation demonstrated that although PDT was effective against Candida species, fluconazole-resistant strains showed reduced sensitivity to PDT. Moreover, single-species biofilms were less susceptible to PDT than their planktonic counterparts. © 2009 Blackwell Verlag GmbH.

  9. Candida albicans SUR7 contributes to secretion, biofilm formation, and macrophage killing

    PubMed Central

    2010-01-01

    Background Candida albicans SUR7 has been shown to be required for plasma membrane organization and cell wall synthesis, but its role in virulence is not known. Using a bioinformatics strategy, we previously identified several novel putative secretion pathway proteins potentially involved in virulence, including the C. albicans homolog of the Saccharomyces cerevisiae endocytosis-related protein Sur7p. We therefore generated a C. albicans sur7Δ null mutant and examined its contribution to key virulence attributes. Results Structurally, the C. albicans sur7Δ mutant was impaired in response to filamentation-inducing conditions, and formed aberrant hyphae with extensive accumulation of plasma membrane-derived structures within the cell. Absence of SUR7 resulted in a temperature-sensitive growth defect at high temperatures (42°C), which was partially rescued by addition of NaCl. We next examined the role of the SUR7 paralog C. albicans FMP45 in this temperature-sensitive phenotype. Analysis of C. albicans Fmp45p-GFP demonstrated co-localization of Fmp45p with Sur7p and increased fluorescence in the plasma membrane in the presence of high salt. We next focused on key virulence-related phenotypes. The C. albicans sur7Δ null mutant exhibited secretory defects: reduced lipase secretion, and increased levels of secreted Sap2p. The null mutant was hyper-susceptible to sub-inhibitory concentrations of caspofungin, but not amphotericin B and 5-fluorocytosine. Functionally, the sur7Δ mutant demonstrated increased adhesion to polystyrene and of note, was markedly defective in biofilm formation. In an in vitro macrophage model of virulence, the sur7Δ mutant was impaired in macrophage killing. Conclusions Plasma membrane and cell wall organization are important for cell morphology, and alterations of these structures contributed to impairment of several key virulence-associated phenotypes in the C. albicans sur7Δ mutant. PMID:20433738

  10. Sensitization of Candida albicans biofilms to fluconazole by terpenoids of plant origin.

    PubMed

    Doke, Sonali Kashinath; Raut, Jayant Shankar; Dhawale, Shashikant; Karuppayil, Sankunny Mohan

    2014-01-01

    Infections associated with the biofilms of Candida albicans are a challenge to antifungal treatment. Combinatorial therapy involving plant molecules with antifungal drugs would be an effective complementary approach against drug-resistant Candida biofilms. The aim of this study was to evaluate the efficacy of three bioactive terpenoids (carvacrol, eugenol and thymol) in combination with fluconazole against planktonic cells, biofilm development and mature biofilms of C. albicans. Activities of the selected molecules were tested using a microplate-based methodology, while their combinations with fluconazole were performed in a checkerboard format. Biofilms were quantitated by XTT-metabolic assay and confirmed by microscopic observations. Combinations of carvacrol and eugenol with fluconazole were found synergistic against planktonic growth of C. albicans, while that of thymol with fluconazole did not have any interaction. Biofilm development and mature biofilms were highly resistant to fluconazole, but susceptible to three terpenoids. Sensitization of cells by sub-inhibitory concentrations of carvacrol and eugenol resulted in prevention of biofilm formation at low fluconazole concentrations, i.e. 0.032 and 0.002 mg ml(-1), respectively. Addition of thymol could not potentiate activity of fluconazole against biofilm formation by C. albicans. Fractional inhibitory concentration indices (FICI) for carvacrol-fluconazole and eugenol-fluconazole combinations for biofilm formation were 0.311 and 0.25, respectively. The FICI value of 1.003 indicated a status of indifference for the combination of thymol and fluconazole against biofilm formation. Eugenol and thymol combinations with fluconazole did not have useful interaction against mature biofilms of C. albicans, but the presence of 0.5 mg ml(-1) of carvacrol caused inhibition of mature biofilms at a significantly low concentration (i.e. 0.032 mg ml(-1)) of fluconazole. The study indicated that carvacrol and eugenol

  11. Glucose modulates antimicrobial photodynamic inactivation of Candida albicans in biofilms.

    PubMed

    Suzuki, Luis Cláudio; Kato, Ilka Tiemy; Prates, Renato Araujo; Sabino, Caetano Padial; Yoshimura, Tania Mateus; Silva, Tamires Oliveira; Ribeiro, Martha Simões

    2017-03-01

    Candida albicans biofilm is a main cause of infections associated with medical devices such as catheters, contact lens and artificial joint prosthesis. The current treatment comprises antifungal chemotherapy that presents low success rates. Photodynamic inactivation (PDI) involves the combination of a photosensitizing compound (PS) and light to generate oxidative stress that has demonstrated effective antimicrobial activity against a broad-spectrum of pathogens, including C. albicans. This fungus senses glucose inducing an upregulation of membrane transporters that can facilitate PS uptake into the cell. The aim of this study was to evaluate the effects of glucose on methylene blue (MB) uptake and its influence on PDI efficiency when combined to a red LED with central wavelength at λ=660nm. C. albicans biofilms were grown on hydrogel disks. Prior to PDI assays, MB uptake tests were performed with and without glucose-sensitization. In this system, the optimum PS administration was determined as 500μM of MB in contact with the biofilm during 30min before irradiation. Irradiation was performed during 3, 6, 9, 12, 15 and 18min with irradiance of 127.3mW/cm(2). Our results showed that glucose was able to increase MB uptake in C. albicans cells. In addition, PDI without glucose showed a higher viability reduction until 6min; after 9min, glucose group demonstrated a significant decrease in cell viability when compared to glucose-free group. Taken together, our data suggest that glucose is capable to enhance MB uptake and modulate photodynamic inactivation of C. albicans biofilm.

  12. Susceptibility of Candida albicans and Candida dubliniensis to Photodynamic Therapy Using Four Dyes as the Photosensitizer.

    PubMed

    Hosseini, Nasim; Yazdanpanah, Samira; Saki, Maryam; Rezazadeh, Fahimeh; Ghapanchi, Janan; Zomorodian, Kamiar

    2016-12-01

    Oral candidiasis is the most common opportunistic infection affecting the human oral cavity. Photodynamic therapy, as one of its proposed treatment modalities, needs a distinct dye for achieving the best effect. The purpose of this study was to evaluate photosensitization effects of four distinct dyes on standard suspension of Candida albicans (C. albicans) and Candida dubliniensis (C. dubliniensis) and biofilm of C. albicans considering the obtained optimum dye concentration and duration of laser irradiation. In this in vitro study, colony forming units (CFU) of two sets of four groups of Laser plus Dye (L+D+), Dye (L-D+), Laser (L+D-) and No Laser, No Dye (L-D-) were assessed individually with different methylene blue concentrations and laser irradiation period. The photodynamic therapy effect on standard suspension of Candida species (using methylene blue, aniline blue, malachite green and crystal violet) were studied based on the obtained results. Similar investigation was performed on biofilm of C. albicans using the spectral absorbance. Data were imported to SPSS and assessed by statistical tests of analysis of variance (ANOVA) and Tukey test (α= 0.05). CFU among the different dye concentration and irradiation time decrease in dose- and time-dependent manner (p> 0.05), all of which were significantly lower than the control groups (p< 0.05). Among the examined photosensitizers, there was no statistically significant difference, (p> 0.05) though all of them were significantly decrease CFU compared with the control groups (p< 0.05). In L+D- and L+D+ groups, biofilm was significantly destroyed more than that of L-D- (p< 0.05). Photodynamic therapy might be used as an effective procedure to treat Candida associated mucocutaneous diseases and killing biofilm in the infected surfaces such as dentures.

  13. Susceptibility of Candida albicans and Candida dubliniensis to Photodynamic Therapy Using Four Dyes as the Photosensitizer

    PubMed Central

    Hosseini, Nasim; Yazdanpanah, Samira; Saki, Maryam; Rezazadeh, Fahimeh; Ghapanchi, Janan; Zomorodian, Kamiar

    2016-01-01

    Statement of the Problem: Oral candidiasis is the most common opportunistic infection affecting the human oral cavity. Photodynamic therapy, as one of its proposed treatment modalities, needs a distinct dye for achieving the best effect. Purpose: The purpose of this study was to evaluate photosensitization effects of four distinct dyes on standard suspension of Candida albicans (C. albicans) and Candida dubliniensis (C. dubliniensis) and biofilm of C. albicans considering the obtained optimum dye concentration and duration of laser irradiation. Materials and Method: In this in vitro study, colony forming units (CFU) of two sets of four groups of Laser plus Dye (L+D+), Dye (L-D+), Laser (L+D-) and No Laser, No Dye (L-D-) were assessed individually with different methylene blue concentrations and laser irradiation period. The photodynamic therapy effect on standard suspension of Candida species (using methylene blue, aniline blue, malachite green and crystal violet) were studied based on the obtained results. Similar investigation was performed on biofilm of C. albicans using the spectral absorbance. Data were imported to SPSS and assessed by statistical tests of analysis of variance (ANOVA) and Tukey test (α= 0.05). Results: CFU among the different dye concentration and irradiation time decrease in dose- and time-dependent manner (p> 0.05), all of which were significantly lower than the control groups (p< 0.05). Among the examined photosensitizers, there was no statistically significant difference, (p> 0.05) though all of them were significantly decrease CFU compared with the control groups (p< 0.05). In L+D- and L+D+ groups, biofilm was significantly destroyed more than that of L-D- (p< 0.05). Conclusion: Photodynamic therapy might be used as an effective procedure to treat Candida associated mucocutaneous diseases and killing biofilm in the infected surfaces such as dentures. PMID:27942552

  14. Effects of a nanoparticulate silica substrate on cell attachment of Candida albicans.

    PubMed

    Cousins, B G; Allison, H E; Doherty, P J; Edwards, C; Garvey, M J; Martin, D S; Williams, R L

    2007-03-01

    To investigate the influence of silica nanoparticles on the attachment and growth of Candida albicans cells. Spherical silica nanoparticles with diameters of 4, 7, 14 or 21 nm were attached to tissue culture polystyrene by a polycationic binding layer using a simple deposition procedure. The modified surfaces were shown to reduce the attachment and growth of C. albicans cells by a range of different measurements including microscopy, staining cells and measuring the amount of dye taken up and total cell activity measured using a dye reduction assay. For those cells that did attach and grow, the nanoparticle-coated surface inhibited the yeast to hyphal transition that is induced in the presence of serum. The greatest effect was observed for 7 and 14 nm diameter silica particles and we propose that the mechanism for these effects are related to either the topography of the surface or the slow dissolution of the bound silica. The attachment and growth of C. albicans is reduced by surface modification with silica nanoparticles. The modification of surfaces by nanoparticulate coatings is a simple process that may have applications in reducing the prevalence of Candida sp. cells on medical devices thus, limiting the incidence of this pathogenic yeast in clinical environments.

  15. Comparison of Sterol Import under Aerobic and Anaerobic Conditions in Three Fungal Species, Candida albicans, Candida glabrata, and Saccharomyces cerevisiae

    PubMed Central

    Zavrel, Martin; Hoot, Sam J.

    2013-01-01

    Sterol import has been characterized under various conditions in three distinct fungal species, the model organism Saccharomyces cerevisiae and two human fungal pathogens Candida glabrata and Candida albicans, employing cholesterol, the sterol of higher eukaryotes, as well as its fungal equivalent, ergosterol. Import was confirmed by the detection of esterified cholesterol within the cells. Comparing the three fungal species, we observe sterol import under three different conditions. First, as previously well characterized, we observe sterol import under low oxygen levels in S. cerevisiae and C. glabrata, which is dependent on the transcription factor Upc2 and/or its orthologs or paralogs. Second, we observe sterol import under aerobic conditions exclusively in the two pathogenic fungi C. glabrata and C. albicans. Uptake emerges during post-exponential-growth phases, is independent of the characterized Upc2-pathway and is slower compared to the anaerobic uptake in S. cerevisiae and C. glabrata. Third, we observe under normoxic conditions in C. glabrata that Upc2-dependent sterol import can be induced in the presence of fetal bovine serum together with fluconazole. In summary, C. glabrata imports sterols both in aerobic and anaerobic conditions, and the limited aerobic uptake can be further stimulated by the presence of serum together with fluconazole. S. cerevisiae imports sterols only in anaerobic conditions, demonstrating aerobic sterol exclusion. Finally, C. albicans imports sterols exclusively aerobically in post-exponential-growth phases, independent of Upc2. For the first time, we provide direct evidence of sterol import into the human fungal pathogen C. albicans, which until now was believed to be incapable of active sterol import. PMID:23475705

  16. Prevalence of Candida albicans and carriage of Candida non-albicans in the saliva of preschool children, according to their caries status.

    PubMed

    Lozano Moraga, Carla Paola; Rodríguez Martínez, Gonzalo Andrés; Lefimil Puente, Claudia Andrea; Morales Bozo, Irene Cecilia; Urzúa Orellana, Blanca Regina

    2017-01-01

    This study was conducted to establish associations among the Candida carriage rate, the diversity of Candida species carried and the different caries status of preschool children. Sixty-one children between 2 and 5 years of age were examined by a single expert examiner and were divided into three groups, the caries-free, moderate caries and severe caries groups, according to the criteria of the International Caries Detection and Assessment System II (ICDAS). Saliva samples were obtained from the members of each group and were plated on Sabouraud agar plates to assess the Candida carriage rates. CHROMagar Candida medium was used for the preliminary screening. Biochemical testing or PCR/sequencing was conducted to identify the different Candida species in the samples. The differences observed were considered significant if the p value was <0.05. The Candida carriage rate and the number of species of this fungus carried were higher in the group with the highest level of caries severity (p < 0.05). Whereas Candida albicans was the most predominant Candida species in the saliva of all of the children, C. dubliniensis was identified only in the most caries-affected group in addition to other rare species of Candida non-albicans. A high salivary Candida carriage rate and the presence of specific species of this fungus (such as C. albicans and C. dubliniensis) appear to be related to the severity of caries experienced by preschool children.

  17. Silver colloidal nanoparticles: antifungal effect against adhered cells and biofilms of Candida albicans and Candida glabrata.

    PubMed

    Monteiro, D R; Gorup, L F; Silva, S; Negri, M; de Camargo, E R; Oliveira, R; Barbosa, D B; Henriques, M

    2011-08-01

    The aim of this study was to evaluate the effect of silver nanoparticles (SN) against Candida albicans and Candida glabrata adhered cells and biofilms. SN (average diameter 5 nm) were synthesized by silver nitrate reduction with sodium citrate and stabilized with ammonia. Minimal inhibitory concentration (MIC) tests were performed for C. albicans (n = 2) and C. glabrata (n = 2) grown in suspension following the Clinical Laboratory Standards Institute microbroth dilution method. SN were applied to adhered cells (2 h) or biofilms (48 h) and after 24 h of contact their effect was assessed by enumeration of colony forming units (CFUs) and quantification of total biomass (by crystal violet staining). The MIC results showed that SN were fungicidal against all strains tested at very low concentrations (0.4-3.3 μg ml(-1)). Furthermore, SN were more effective in reducing biofilm biomass when applied to adhered cells (2 h) than to pre-formed biofilms (48 h), with the exception of C. glabrata ATCC, which in both cases showed a reduction ∼90%. Regarding cell viability, SN were highly effective on adhered C. glabrata and respective biofilms. On C. albicans the effect was not so evident but there was also a reduction in the number of viable biofilm cells. In summary, SN may have the potential to be an effective alternative to conventional antifungal agents for future therapies in Candida-associated denture stomatitis.

  18. Purification and characterisation of a metallopeptidase of Candida albicans.

    PubMed

    el Moudni, B; Rodier, M H; Barrault, C; Ghazali, M; Jacquemin, J L

    1995-10-01

    A novel aminopeptidase was purified by high performance liquid chromatography from a cytosoluble 100,000 g extract of Candida albicans on the basis of its ability to cleave L-arginine 7-amino-4-methylcoumarin. The purification factor was 36 and the yield was 20%. The native enzyme had a mol. wt of 52 kDa as demonstrated by SDS-PAGE in the presence or absence of reducing conditions and exhibited an iso-electric point of 4.3. The aminopeptidase showed optimum activity at pH 7.2, a Michaelis constant of c. 50 microM and a Vmax at 19 mM AMC released/min/mg of protein for L-Arg-AMC. This enzyme was shown to cleave at low affinity L-leucine-7-amino-4-methylcoumarin as demonstrated by the spectrofluorimetric method. The enzyme was strongly inhibited by specific metallo-enzyme inhibitors-EDTA and o-phenanthroline. Furthermore, there is evidence that a similar or identical enzyme occurs in other C. albicans clinical isolates and other Candida spp.

  19. Ultrastructural analysis of Candida albicans when exposed to silver nanoparticles.

    PubMed

    Vazquez-Muñoz, Roberto; Avalos-Borja, Miguel; Castro-Longoria, Ernestina

    2014-01-01

    Candida albicans is the most common fungal pathogen in humans, and recently some studies have reported the antifungal activity of silver nanoparticles (AgNPs) against some Candida species. However, ultrastructural analyses on the interaction of AgNPs with these microorganisms have not been reported. In this work we evaluated the effect of AgNPs on C. albicans, and the minimum inhibitory concentration (MIC) was found to have a fungicidal effect. The IC50 was also determined, and the use of AgNPs with fluconazole (FLC), a fungistatic drug, reduced cell proliferation. In order to understand how AgNPs interact with living cells, the ultrastructural distribution of AgNPs in this fungus was determined. Transmission electron microscopy (TEM) analysis revealed a high accumulation of AgNPs outside the cells but also smaller nanoparticles (NPs) localized throughout the cytoplasm. Energy dispersive spectroscopy (EDS) analysis confirmed the presence of intracellular silver. From our results it is assumed that AgNPs used in this study do not penetrate the cell, but instead release silver ions that infiltrate into the cell leading to the formation of NPs through reduction by organic compounds present in the cell wall and cytoplasm.

  20. Ultrastructural Analysis of Candida albicans When Exposed to Silver Nanoparticles

    PubMed Central

    Vazquez-Muñoz, Roberto; Avalos-Borja, Miguel; Castro-Longoria, Ernestina

    2014-01-01

    Candida albicans is the most common fungal pathogen in humans, and recently some studies have reported the antifungal activity of silver nanoparticles (AgNPs) against some Candida species. However, ultrastructural analyses on the interaction of AgNPs with these microorganisms have not been reported. In this work we evaluated the effect of AgNPs on C. albicans, and the minimum inhibitory concentration (MIC) was found to have a fungicidal effect. The IC50 was also determined, and the use of AgNPs with fluconazole (FLC), a fungistatic drug, reduced cell proliferation. In order to understand how AgNPs interact with living cells, the ultrastructural distribution of AgNPs in this fungus was determined. Transmission electron microscopy (TEM) analysis revealed a high accumulation of AgNPs outside the cells but also smaller nanoparticles (NPs) localized throughout the cytoplasm. Energy dispersive spectroscopy (EDS) analysis confirmed the presence of intracellular silver. From our results it is assumed that AgNPs used in this study do not penetrate the cell, but instead release silver ions that infiltrate into the cell leading to the formation of NPs through reduction by organic compounds present in the cell wall and cytoplasm. PMID:25290909

  1. Membrane of Candida albicans as a target of berberine.

    PubMed

    Zorić, Nataša; Kosalec, Ivan; Tomić, Siniša; Bobnjarić, Ivan; Jug, Mario; Vlainić, Toni; Vlainić, Josipa

    2017-05-17

    We investigated the mechanisms of anti-Candida action of isoquinoline alkaloid berberine, active constituent of medically important plants of Barberry species. The effects on membrane, morphological transition, synthesis of ergosterol and the consequent changes in membrane permeability have been studied. Polarization and lipid peroxidation level of the membrane following berberine treatment have been addressed. Minimal inhibitory concentration (MIC) of berberine against C. albicans was 17.75 μg/mL. Cytotoxic effect of berberine was concentration dependent, and in sub-MIC concentrations inhibit morphological transition of C. albicans cells to its filamentous form. Results showed that berberine affects synthesis of membrane ergosterol dose-dependently and induces increased membrane permeability causing loss of intracellular material to the outer space (DNA/protein leakage). Berberine also caused membrane depolarization and lipid peroxidation of membrane constituents indicating its direct effect on the membrane. Moreover, ROS levels were also increased following berberine treatment indicating further the possibility of membrane damage. Based on the obtained results it seems that berberine achieves its anti-Candida activity by affecting the cell membrane.

  2. Antifungal activity of Lavandula angustifolia essential oil against Candida albicans yeast and mycelial form.

    PubMed

    D'Auria, F D; Tecca, M; Strippoli, V; Salvatore, G; Battinelli, L; Mazzanti, G

    2005-08-01

    The antifungal activity of the essential oil of Lavandula angustifolia Mill. (lavender oil) and its main components, linalool and linalyl acetate, was investigated against 50 clinical isolates of Candida albicans (28 oropharyngeal strains, 22 vaginal strains) and C. albicans ATCC 3153. Growth inhibition, killing time and inhibition of germ tube formation were evaluated. The chemical composition of the essential oil was determined by gas chromatography and mass spectrometry. Lavender oil inhibited C. albicans growth: mean minimum inhibitory concentration (MIC) of 0.69% (vol./vol.) (vaginal strains) and 1.04% (oropharyngeal strains); mean MFC of 1.1% (vaginal strains) and 1.8% (oropharyngeal strains). Linalool was more effective than essential oil: mean MIC of 0.09% (vaginal strains) and 0.29% (oropharyngeal strains); mean MFC of 0.1% (vaginal strains) and 0.3% (oropharyngeal strains). Linalyl acetate was almost ineffective. Lavender oil (2%) killed 100% of the C. albicans ATCC 3153 cells within 15 min; linalool (0.5%) killed 100% of the cells within 30 s. The essential oil inhibited germ tube formation (mean MIC of 0.09%), as did the main components (MIC of 0.11% for linalool and 0.08% for linalyl acetate). Both the essential oil and its main components inhibited hyphal elongation of C. albicans ATCC 3153 (about 50% inhibition at 0.016% with each substance). Lavender oil shows both fungistatic and fungicidal activity against C. albicans strains. At lower concentrations, it inhibits germ tube formation and hyphal elongation, indicating that it is effective against C. albicans dimorphism and may thus reduce fungal progression and the spread of infection in host tissues.

  3. Differentiation of Candida dubliniensis from Candida albicans on rosemary extract agar and oregano extract agar.

    PubMed

    de Loreto, Erico Silva; Pozzatti, Patrícia; Alves Scheid, Liliane; Santurio, Deise; Morais Santurio, Janio; Alves, Sydney Hartz

    2008-01-01

    Candida dubliniensis is a recently described pathogenic species which shares many phenotypic features with Candida albicans and therefore, may be misidentified in microbiological laboratories. Because molecular methods can be onerous and unfeasible in routine mycological laboratories with restricted budgets such as those in developing countries, phenotypic techniques have been encouraged in the development of differential media for the presumptive identification of these species. We examined the colony morphology and chlamydospore production of 30 C. dubliniensis isolates and 100 C. albicans isolates on two new proposed media: rosemary (Rosmarinus officinalis) extract agar (REA) and oregano (Origanum vulgare) extract agar (OEA). These substrates are traditionally used as spices and medicinal herbs. In both of these media, all C. dubliniensis isolates (100%) showed rough colonies with peripheral hyphal fringes and abundant chlamydospores after 24 to 48 hr of incubation at 25 degrees C. In contrast, under the same conditions, all isolates of C. albicans (100%) showed smooth colonies without hyphal fringes or chlamydospores. In conclusion, REA and OEA offer a simple, rapid, and inexpensive screening media for the differentiation of C. albicans and C. dubliniensis.

  4. Pathogenicity of Candida tropicalis and Candida albicans after gastrointestinal inoculation in mice.

    PubMed Central

    Wingard, J R; Dick, J D; Merz, W G; Sandford, G R; Saral, R; Burns, W H

    1980-01-01

    The ability of clinical isolates of Candida albicans and candida tropicalis to invade through normal and damaged gastrointestinal mucosa was determined. Adult mice were treated with either gentamicin or gentamicin and cytarabine. Suspensions of yeast cells (10(7)) were administered through a catheter intraesophageally. Invasion was determined by culturing liver, kidney, and lung tissue from mice sacrificed after 48 h. C. albicans and C. tropicalis were incapable of invading through normal gastrointestinal mucosa in mice treated only with gentamicin. Two isolates of C. tropicalis penetrated the damaged gastrointestinal mucosa in 69% (49 of 71) of mice treated with gentamicin and cytarabine. In contrast, three isolates of C. albicans penetrated he damaged gastrointestinal mucosa in only 23% (14 of 62) of mice. These results suggest that C. tropicalis is more capable of invading through damaged gastrointestinal mucosa than C. albicans. The observations in this mouse model parallel those seen in patients on cytotoxic drugs. Therefore, this model offers a tool for investigation of the pathogenicity of these organisms in a model analogous to the compromised host. Images Fig. 2 PMID:7011986

  5. Deletions of endocytic components VPS28 and VPS32 affect growth at alkaline pH and virulence through both RIM101-dependent and RIM101-independent pathways in Candida albicans.

    PubMed

    Cornet, Muriel; Bidard, Frédérique; Schwarz, Patrick; Da Costa, Grégory; Blanchin-Roland, Sylvie; Dromer, Françoise; Gaillardin, Claude

    2005-12-01

    Ambient pH signaling involves a cascade of conserved Rim or Pal products in ascomycetous yeasts or filamentous fungi, respectively. Recent evidences in the fungi Aspergillus nidulans, Saccharomyces cerevisiae, Yarrowia lipolytica, and Candida albicans suggested that components of endosomal sorting complexes required for transport (ESCRT) involved in endocytic trafficking were needed for signal transduction along the Rim pathway. In this study, we confirm these findings with C. albicans and show that Vps28p (ESCRT-I) and Vps32p/Snf7p (ESCRT-III) are required for the transcriptional regulation of known targets of the Rim pathway, such as the PHR1 and PHR2 genes encoding cell surface proteins, which are expressed at alkaline and acidic pH, respectively. We additionally show that deletion of these two VPS genes, particularly VPS32, has a more drastic effect than a RIM101 deletion on growth at alkaline pH and that this effect is only partially suppressed by expression of a constitutively active form of Rim101p. Finally, in an in vivo mouse model, both vps null mutants were significantly less virulent than a rim101 mutant, suggesting that VPS28 and VPS32 gene products affect virulence both through Rim-dependent and Rim-independent pathways.

  6. Hypoxia and Temperature Regulated Morphogenesis in Candida albicans

    PubMed Central

    Kurtz, Dagmar; Juchimiuk, Mateusz; Ernst, Joachim F.

    2015-01-01

    Candida albicans is a common commensal in the human gut but in predisposed patients it can become an important human fungal pathogen. As a commensal, C. albicans adapts to low-oxygen conditions and represses its hyphal development by the transcription factor Efg1, which under normoxia activates filamentation. The repressive hypoxic but not the normoxic function of Efg1 required its unmodified N-terminus, was prevented by phosphomimetic residues at normoxic phosphorylation sites T179 and T206 and occurred only at temperatures ≤35°C. Genome-wide binding sites for native Efg1 identified 300 hypoxia-specific target genes, which overlapped partially with hypoxic binding sites for Ace2, a known positive regulator of hypoxic filamentation. Transcriptional analyses revealed that EFG1, ACE2 and their identified targets BCR1 and BRG1 encode an interconnected regulatory hub, in which Efg1/Bcr1 act as negative and Ace2/Brg1 act as positive regulators of gene expression under hypoxia. In this circuit, the hypoxic function of Ace2 was stimulated by elevated CO2 levels. The hyperfilamentous phenotype of efg1 and bcr1 mutants depended on Ace2/Brg1 regulators and required increased expression of genes encoding Cek1 MAP kinase and its downstream target Cph1. The intricate temperature-dependent regulatory mechanisms under hypoxia suggest that C. albicans restricts hyphal morphogenesis in oxygen-poor body niches, possibly to persist as a commensal in the human host. PMID:26274602

  7. Distribution of Candida albicans genotypes among family members

    NASA Technical Reports Server (NTRS)

    Mehta, S. K.; Stevens, D. A.; Mishra, S. K.; Feroze, F.; Pierson, D. L.

    1999-01-01

    Thirty-three families (71 subjects) were screened for the presence of Candida albicans in mouthwash or stool specimens; 12 families (28 subjects) were culture-positive for this yeast. An enrichment procedure provided a twofold increase in the recovery of C. albicans from mouthwash specimens. Nine of the twelve culture-positive families had two positive members each, two families had three positive members each, and one family had four positive members. Genetic profiles were obtained by three methods: pulsed-field gel electrophoresis; restriction endonuclease analysis, and random amplification of polymorphic DNA analysis. DNA fingerprinting of C. albicans isolated from one body site three consecutive times revealed that each of the 12 families carried a distinct genotype. No two families shared the same strain, and two or more members of a family commonly shared the same strain. Intrafamily genotypic identity (i.e., each member within the family harbored the same strain) was demonstrated in six families. Genotypes of isolates from husband and wife differed from one another in five families. All three methods were satisfactory in determining genotypes; however, we concluded that restriction endonuclease analysis provided adequate resolving power.

  8. Potent Synergy between Spirocyclic Pyrrolidinoindolinones and Fluconazole against Candida albicans.

    PubMed

    Premachandra, Ilandari Dewage Udara Anulal; Scott, Kevin A; Shen, Chengtian; Wang, Fuqiang; Lane, Shelley; Liu, Haoping; Van Vranken, David L

    2015-10-01

    A spiroindolinone, (1S,3R,3aR,6aS)-1-benzyl-6'-chloro-5-(4-fluorophenyl)-7'-methylspiro[1,2,3a,6a-tetrahydropyrrolo[3,4-c]pyrrole-3,3'-1H-indole]-2',4,6-trione, was previously reported to enhance the antifungal effect of fluconazole against Candida albicans. A diastereomer of this compound was synthesized, along with various analogues. Many of the compounds were shown to enhance the antifungal effect of fluconazole against C. albicans, some with exquisite potency. One spirocyclic piperazine derivative, which we have named synazo-1, was found to enhance the effect of fluconazole with an EC50 value of 300 pM against a susceptible strain of C. albicans and going as low as 2 nM against some resistant strains. Synazo-1 exhibits true synergy with fluconazole, with an FIC index below 0.5 in the strains tested. Synazo-1 exhibited low toxicity in mammalian cells relative to the concentrations required for antifungal synergy.

  9. Hypoxia and Temperature Regulated Morphogenesis in Candida albicans.

    PubMed

    Desai, Prashant R; van Wijlick, Lasse; Kurtz, Dagmar; Juchimiuk, Mateusz; Ernst, Joachim F

    2015-08-01

    Candida albicans is a common commensal in the human gut but in predisposed patients it can become an important human fungal pathogen. As a commensal, C. albicans adapts to low-oxygen conditions and represses its hyphal development by the transcription factor Efg1, which under normoxia activates filamentation. The repressive hypoxic but not the normoxic function of Efg1 required its unmodified N-terminus, was prevented by phosphomimetic residues at normoxic phosphorylation sites T179 and T206 and occurred only at temperatures ≤35°C. Genome-wide binding sites for native Efg1 identified 300 hypoxia-specific target genes, which overlapped partially with hypoxic binding sites for Ace2, a known positive regulator of hypoxic filamentation. Transcriptional analyses revealed that EFG1, ACE2 and their identified targets BCR1 and BRG1 encode an interconnected regulatory hub, in which Efg1/Bcr1 act as negative and Ace2/Brg1 act as positive regulators of gene expression under hypoxia. In this circuit, the hypoxic function of Ace2 was stimulated by elevated CO2 levels. The hyperfilamentous phenotype of efg1 and bcr1 mutants depended on Ace2/Brg1 regulators and required increased expression of genes encoding Cek1 MAP kinase and its downstream target Cph1. The intricate temperature-dependent regulatory mechanisms under hypoxia suggest that C. albicans restricts hyphal morphogenesis in oxygen-poor body niches, possibly to persist as a commensal in the human host.

  10. Candida albicans repetitive elements display epigenetic diversity and plasticity

    PubMed Central

    Freire-Benéitez, Verónica; Price, R. Jordan; Tarrant, Daniel; Berman, Judith; Buscaino, Alessia

    2016-01-01

    Transcriptionally silent heterochromatin is associated with repetitive DNA. It is poorly understood whether and how heterochromatin differs between different organisms and whether its structure can be remodelled in response to environmental signals. Here, we address this question by analysing the chromatin state associated with DNA repeats in the human fungal pathogen Candida albicans. Our analyses indicate that, contrary to model systems, each type of repetitive element is assembled into a distinct chromatin state. Classical Sir2-dependent hypoacetylated and hypomethylated chromatin is associated with the rDNA locus while telomeric regions are assembled into a weak heterochromatin that is only mildly hypoacetylated and hypomethylated. Major Repeat Sequences, a class of tandem repeats, are assembled into an intermediate chromatin state bearing features of both euchromatin and heterochromatin. Marker gene silencing assays and genome-wide RNA sequencing reveals that C. albicans heterochromatin represses expression of repeat-associated coding and non-coding RNAs. We find that telomeric heterochromatin is dynamic and remodelled upon an environmental change. Weak heterochromatin is associated with telomeres at 30 °C, while robust heterochromatin is assembled over these regions at 39 °C, a temperature mimicking moderate fever in the host. Thus in C. albicans, differential chromatin states controls gene expression and epigenetic plasticity is linked to adaptation. PMID:26971880

  11. Fluconazole Assists Berberine To Kill Fluconazole-Resistant Candida albicans

    PubMed Central

    Li, De-Dong; Xu, Yi; Zhang, Da-Zhi; Quan, Hua; Mylonakis, Eleftherios; Hu, Dan-Dan; Li, Ming-Bang; Zhao, Lan-Xue; Zhu, Liang-Hua

    2013-01-01

    It was found in our previous study that berberine (BBR) and fluconazole (FLC) used concomitantly exhibited a synergism against FLC-resistant Candida albicans in vitro. The aim of the present study was to clarify how BBR and FLC worked synergistically and the underlying mechanism. Antifungal time-kill curves indicated that the synergistic effect of the two drugs was BBR dose dependent rather than FLC dose dependent. In addition, we found that BBR accumulated in C. albicans cells, especially in the nucleus, and resulted in cell cycle arrest and significant change in the transcription of cell cycle-related genes. Besides BBR, other DNA intercalators, including methylene blue, sanguinarine, and acridine orange, were all found to synergize with FLC against FLC-resistant C. albicans. Detection of intracellular BBR accumulation by fluorescence measurement showed that FLC played a role in increasing intracellular BBR concentration, probably due to its effect in disrupting the fungal cell membrane. Similar to the case with FLC, other antifungal agents acting on the cell membrane were able to synergize with BBR. Interestingly, we found that the efflux of intracellular BBR was FLC independent but strongly glucose dependent and associated with the drug efflux pump Cdr2p. These results suggest that BBR plays a major antifungal role in the synergism of FLC and BBR, while FLC plays a role in increasing the intracellular BBR concentration. PMID:24060867

  12. Photodynamic therapy with Pc 4 induces apoptosis of Candida albicans.

    PubMed

    Lam, Minh; Jou, Paul C; Lattif, Ali A; Lee, Yoojin; Malbasa, Christi L; Mukherjee, Pranab K; Oleinick, Nancy L; Ghannoum, Mahmoud A; Cooper, Kevin D; Baron, Elma D

    2011-01-01

    The high prevalence of drug resistance necessitates the development of novel antifungal agents against infections caused by opportunistic fungal pathogens, such as Candida albicans. Elucidation of apoptosis in yeast-like fungi may provide a basis for future therapies. In mammalian cells, photodynamic therapy (PDT) has been demonstrated to generate reactive oxygen species, leading to immediate oxidative modifications of biological molecules and resulting in apoptotic cell death. In this report, we assess the in vitro cytotoxicity and mechanism of PDT, using the photosensitizer Pc 4, in planktonic C. albicans. Confocal image analysis confirmed that Pc 4 localizes to cytosolic organelles, including mitochondria. A colony formation assay showed that 1.0 μM Pc 4 followed by light at 2.0 J cm(-2) reduced cell survival by 4 logs. XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide) assay revealed that Pc 4-PDT impaired fungal metabolic activity, which was confirmed using the FUN-1 (2-chloro-4-[2,3-dihydro-3-methyl-(benzo-1,3-thiazol-2-yl)-methylidene]-1-phenylquinolinium iodide) fluorescence probe. Furthermore, we observed changes in nuclear morphology characteristic of apoptosis, which were substantiated by increased externalization of phosphatidylserine and DNA fragmentation following Pc 4-PDT. These data indicate that Pc 4-PDT can induce apoptosis in C. albicans. Therefore, a better understanding of the process will be helpful, as PDT may become a useful treatment option for candidiasis.

  13. Impact of Low Frequency Electromagnetic Field Exposure on the Candida Albicans

    NASA Astrophysics Data System (ADS)

    Malíková, Ivona; Janoušek, Ladislav; Fantova, Vladyslava; Jíra, Jaroslav; Kříha, Vítĕzslav

    2015-03-01

    Effect of low frequency electromagnetic field on growth of selected microorganism is studied in the article. The diploid fungus that grows both as yeast and filamentous cell was chosen for this research. The theory of ion parametric resonance was taken as the base for studying the influence of electromagnetic field on biological structures. We tested the hypothesis, whether it is possible to observe the change in growth properties of Candida albicans with an AC electromagnetic field tuned to resonance with calcium ions cyclotron frequency.

  14. Gastrointestinal Colonization by Candida albicans Mutant Strains in Antibiotic-Treated Mice

    PubMed Central

    Wiesner, Stephen M.; Jechorek, Robert P.; Garni, Robb M.; Bendel, Catherine M.; Wells, Carol L.

    2001-01-01

    Antibiotic-treated mice orally inoculated with one of three Candida albicans strains (including two mutant strains) or indigenous Candida pelliculosa showed levels of candidal gastrointestinal colonization that were strain specific. However, regardless of strain, the numbers of viable candida were intermediate to high in the stomach, were consistently lowest in the upper small intestine, and increased progressively down the intestinal tract. PMID:11139219

  15. Antiarthritic effect of lonicerin on Candida albicans arthritis in mice.

    PubMed

    Lee, Jue-Hee; Han, Yongmoon

    2011-05-01

    Fungal arthritis is a potentially serious disease resulting in rapid destruction of the joint. Among the various Candida species, Candida albicans is the most commonly associated with fungal arthritis. In the present study, we examined the effect of lonicerin, a flavonoid isolated from Lonicerae Flos, on an arthritis caused by C. albicans cell wall (CACW) in mice. To examine the effect, an emulsified mixture of CACW and complete Freund's adjuvant (CACW/CFA) was injected into BALB/c mice via hind footpad route on days -3, -2, and -1. On Day 0, mice with the swollen footpad received lonicerin at 1 or 2 mg/dose/time intraperitoneally 3 times every other day. The footpad-swelling was measured for 20 days. Results showed that the lonicerin treatment reduced the edema at all dose levels, and, furthermore, there was app. 54% edema reduction in animals given the 2 mg-dose at the peak (day 10) of septic arthritis (p < 0.05). Since the peak, the edema was reduced in similar rates. This antiarthritic activity appeared to be mediated by lonicerin's ability to suppress T cell proliferation, nitric oxide production from macrophages, and shift of cellular immunity from Th1- toward Th2-type responses, all of which are beneficial to treat arthritis. In addition, the flavonoid had anticandidal activity (p < 0.01). These data suggest that lonicerin alone, which has both anti-arthritic and antifungal activities, can result in a combination therapy for the treatment of fungal arthritis due to C. albicans infection.

  16. Iron deprivation induces EFG1-mediated hyphal development in Candida albicans without affecting biofilm formation.

    PubMed

    Hameed, Saif; Prasad, Tulika; Banerjee, Dibyendu; Chandra, Aparna; Mukhopadhyay, Chinmay K; Goswami, Shyamal K; Lattif, Ali Abdul; Chandra, Jyotsna; Mukherjee, Pranab K; Ghannoum, Mahmoud A; Prasad, Rajendra

    2008-08-01

    In this study, we investigated the role of cellular iron status in hyphae and biofilm formation in Candida albicans. Iron deprivation by a chelator, bathophenanthrolene disulfonic acid, promoted hyphal development even in nonhyphal-inducing media without affecting growth of C. albicans cells. Iron-acquisition defective mutants, Deltaftr1 and Deltaccc2, also showed hyphal formation, which was prevented by iron supplementation. Notably, most of the tested morphological mutants Deltacph1, Deltaefh1 and Deltatpk1 continued to form hyphae under iron-deprived conditions, except the Deltaefg1 null mutant, which showed a complete block in hyphae formation. The role of EFG1 in filamentation under iron-deprived conditions was further confirmed by Northern analysis, which showed a considerable upregulation of the EFG1 transcript. Of notable importance, all the morphological mutants including Deltaefg1 mutant possessed enhanced membrane fluidity under iron-deprived conditions; however, this did not appear to contribute to hyphal development. Interestingly, iron deprivation did not affect the ability of C. albicans to form biofilms on the catheter surface and led to no gross defects in azole resistance phenotype of these biofilms of C. albicans cells. Our study, for the first time, establishes a link between cellular iron, Efg1p and hyphal development of C. albicans cells that is independent of biofilm formation.

  17. Sodium ascorbate kills Candida albicans in vitro via iron-catalyzed Fenton reaction: importance of oxygenation and metabolism.

    PubMed

    Avci, Pinar; Freire, Fernanda; Banvolgyi, Andras; Mylonakis, Eleftherios; Wikonkal, Norbert M; Hamblin, Michael R

    2016-12-01

    Ascorbate can inhibit growth and even decrease viability of various microbial species including Candida albicans. However the optimum conditions and the mechanism of action are unclear. Materials/methodology: Candida albicans shaken for 90 min in a buffered solution of ascorbate (90 mM) gave a 5-log reduction of cell viability, while there was no killing without shaking, in growth media with different carbon sources or at 4°C. Killing was inhibited by the iron chelator 2,2'-bipyridyl. Hydroxyphenyl fluorescein probe showed the intracellular generation of hydroxyl radicals. Ascorbate-mediated killing of C. albicans depends on oxygenation and metabolism, involves iron-catalyzed generation of hydroxyl radicals via Fenton reaction and depletion of intracellular NADH. Ascorbate could serve as a component of a topical antifungal therapy.

  18. A subpopulation of Candida albicans and Candida tropicalis biofilm cells are highly tolerant to chelating agents.

    PubMed

    Harrison, Joe J; Turner, Raymond J; Ceri, Howard

    2007-07-01

    Many Candida spp. produce surface-adherent biofilm populations that are resistant to antifungal compounds and other environmental stresses. Recently, certain chelating agents have been recognized as having strong antimicrobial activity against biofilms of Candida species. This study investigated and characterized the concentration- and time-dependent killing of Candida biofilms by the chelators tetrasodium EDTA and sodium diethyldithiocarbamate. Here, Candida albicans and Candida tropicalis biofilms were cultivated in the Calgary Biofilm Device and then exposed to gradient arrays of these agents. Population survival was evaluated by viable cell counting and by confocal laser scanning microscopy (CLSM) in conjunction with fluorescent viability staining. At concentrations of > or =2 mM, both EDTA and diethyldithiocarbamate killed c. 90-99.5% of the biofilm cell populations. Notably, a small fraction (c. 0.5-10%) of biofilm cells were able to withstand the highest concentrations of these antifungals that were tested (16 and 32 mM for EDTA and diethyldithiocarbamate, respectively). Interestingly, CLSM revealed that these surviving cells were irregularly distributed throughout the biofilm community. These data suggest that the use of chelating agents against biofilms of Candida spp. may be limited by the refractory nature of a variant cell subpopulation in the surface-adherent community.

  19. Induction of petite mutation with acriflavine and elevated temperature in Candida albicans.

    PubMed

    Aoki, S; Ito-Kuwa, S

    1987-08-01

    A method of inducing respiratory deficient (petite) mutation in Candida albicans (which has been previously classed as a petite-negative yeast) and characteristics of some isolated mutants are reported. When grown at 42 degrees C in the presence of a cytoplasmic mutagen (acriflavine), C. albicans exhibited diauxie-like biphasic growth. Mutants which were unable to grow on a non-fermentable substrate, glycerol, were isolated from the above culture at a frequency of less than 1%. The simultaneous action of both acriflavine and a supraoptimal temperature of 42 degrees C was required to induce respiratory mutation. The respiratory mutants were separated into two groups: i. mutants exhibiting a complete cytochrome spectrum but with low respiratory activity and ii. those deficient in cytochrome aa3. Further characterization of their respiratory activity, colony morphology, mitochondrial morphology and growth manner supported the evidence that members of the latter group can be regarded as petite mutants.

  20. Regulation of white-opaque switching in Candida albicans.

    PubMed

    Morschhäuser, Joachim

    2010-08-01

    The yeast Candida albicans is part of the microflora in most healthy people, but can become a pathogen when host defenses are compromised. The phenotypic plasticity of C. albicans, which includes switching between different morphologies, contributes to its ability to colonize and infect virtually all body locations. A particularly fascinating developmental program is white-opaque switching, a reversible transition between the normal yeast morphology (white) and an elongated cell type (opaque), which is the mating-competent form of this fungus. Although opaque cells are much less able than white cells to cause a systemic infection, they are better adapted for colonization of specific host niches, like skin. White-opaque switching is controlled by the mating type locus (MTL), which in most C. albicans strains exists in two alleles, MTLa and MTL. These strains produce a heterodimeric repressor, a1-alpha2, which suppresses switching to the opaque phase by inhibiting expression of the master regulator Wor1. Loss of MTL heterozygosity relieves this repression, a mechanism that ensures that only MTL homozygous cells can switch to the mating-competent opaque form. Several transcriptional feedback loops, including positive autoregulation of Wor1, result in bistable expression of the master regulator (low in white and high in opaque cells) and epigenetic inheritance of the two phases. White-opaque switching occurs stochastically at a low frequency, but certain environmental conditions can drive the switch from one phase to the other by affecting either the activity of the transcriptional feedback loops or accumulation of Wor1 protein in a cell. Such environmental regulation of phenotypic switching may restrict mating to suitable host niches, while allowing a C. albicans population to withstand the various challenges encountered in different tissues.

  1. Competitive Fitness of Fluconazole-Resistant Clinical Candida albicans Strains.

    PubMed

    Popp, Christina; Hampe, Irene A I; Hertlein, Tobias; Ohlsen, Knut; Rogers, P David; Morschhäuser, Joachim

    2017-07-01

    The pathogenic yeast Candida albicans can develop resistance to the widely used antifungal agent fluconazole, which inhibits ergosterol biosynthesis. Resistance is often caused by gain-of-function mutations in the transcription factors Mrr1 and Tac1, which result in constitutive overexpression of multidrug efflux pumps, and Upc2, which result in constitutive overexpression of ergosterol biosynthesis genes. However, the deregulated gene expression that is caused by hyperactive forms of these transcription factors also reduces the fitness of the cells in the absence of the drug. To investigate whether fluconazole-resistant clinical C. albicans isolates have overcome the fitness costs of drug resistance, we assessed the relative fitness of C. albicans isolates containing resistance mutations in these transcription factors in competition with matched drug-susceptible isolates from the same patients. Most of the fluconazole-resistant isolates were outcompeted by the corresponding drug-susceptible isolates when grown in rich medium without fluconazole. On the other hand, some resistant isolates with gain-of-function mutations in MRR1 did not exhibit reduced fitness under these conditions. In a mouse model of disseminated candidiasis, three out of four tested fluconazole-resistant clinical isolates did not exhibit a significant fitness defect. However, all four fluconazole-resistant isolates were outcompeted by the matched susceptible isolates in a mouse model of gastrointestinal colonization, demonstrating that the effects of drug resistance on in vivo fitness depend on the host niche. Collectively, our results indicate that the fitness costs of drug resistance in C. albicans are not easily remediated, especially when proper control of gene expression is required for successful adaptation to life within a mammalian host. Copyright © 2017 American Society for Microbiology.

  2. Adaptation of Candida albicans to Reactive Sulfur Species.

    PubMed

    Chebaro, Yasmin; Lorenz, Michael; Fa, Alice; Zheng, Rui; Gustin, Michael

    2017-05-01

    Candida albicans is an opportunistic fungal pathogen that is highly resistant to different oxidative stresses. How reactive sulfur species (RSS) such as sulfite regulate gene expression and the role of the transcription factor Zcf2 and the sulfite exporter Ssu1 in such responses are not known. Here, we show that C. albicans specifically adapts to sulfite stress and that Zcf2 is required for that response as well as induction of genes predicted to remove sulfite from cells and to increase the intracellular amount of a subset of nitrogen metabolites. Analysis of mutants in the sulfate assimilation pathway show that sulfite conversion to sulfide accounts for part of sulfite toxicity and that Zcf2-dependent expression of the SSU1 sulfite exporter is induced by both sulfite and sulfide. Mutations in the SSU1 promoter that selectively inhibit induction by the reactive nitrogen species (RNS) nitrite, a previously reported activator of SSU1, support a model for C. albicans in which Cta4-dependent RNS induction and Zcf2-dependent RSS induction are mediated by parallel pathways, different from S. cerevisiae in which the transcription factor Fzf1 mediates responses to both RNS and RSS. Lastly, we found that endogenous sulfite production leads to an increase in resistance to exogenously added sulfite. These results demonstrate that C. albicans has a unique response to sulfite that differs from the general oxidative stress response, and that adaptation to internal and external sulfite is largely mediated by one transcription factor and one effector gene. Copyright © 2017 by the Genetics Society of America.

  3. In vitro expression of Candida albicans alcohol dehydrogenase genes involved in acetaldehyde metabolism.

    PubMed

    Bakri, M M; Rich, A M; Cannon, R D; Holmes, A R

    2015-02-01

    Alcohol consumption is a risk factor for oral cancer, possibly via its conversion to acetaldehyde, a known carcinogen. The oral commensal yeast Candida albicans may be one of the agents responsible for this conversion intra-orally. The alcohol dehydrogenase (Adh) family of enzymes are involved in acetaldehyde metabolism in yeast but, for C. albicans it is not known which family member is responsible for the conversion of ethanol to acetaldehyde. In this study we determined the expression of mRNAs from three C. albicans Adh genes (CaADH1, CaADH2 and CaCDH3) for cells grown in different culture media at different growth phases by Northern blot analysis and quantitative reverse transcription polymerase chain reaction. CaADH1 was constitutively expressed under all growth conditions but there was differential expression of CaADH2. CaADH3 expression was not detected. To investigate whether CaAdh1p or CaAdh2p can contribute to alcohol catabolism in C. albicans, each gene from the reference strain C. albicans SC5314 was expressed in Saccharomyces cerevisiae. Cell extracts from an CaAdh1p-expressing S. cerevisiae recombinant, but not an CaAdh2p-expressing recombinant, or an empty vector control strain, possessed ethanol-utilizing Adh activity above endogenous S. cerevisiae activity. Furthermore, expression of C. albicans Adh1p in a recombinant S. cerevisiae strain in which the endogenous ScADH2 gene (known to convert ethanol to acetaldehyde in this yeast) had been deleted, conferred an NAD-dependent ethanol-utilizing, and so acetaldehyde-producing, Adh activity. We conclude that CaAdh1p is the enzyme responsible for ethanol use under in vitro growth conditions, and may contribute to the intra-oral production of acetaldehyde.

  4. Distribution of Candida albicans and non-albicans Candida species in oral candidiasis patients: Correlation between cell surface hydrophobicity and biofilm forming activities.

    PubMed

    Muadcheingka, Thaniya; Tantivitayakul, Pornpen

    2015-06-01

    The purposes of this investigation were to study the prevalence of Candida albicans and non-albicans Candida (NAC) species from oral candidiasis patients and evaluate the cell surface hydrophobicity (CSH) and biofilm forming capacity of the clinical isolates Candida species from oral cavity. This study identified a total of 250 Candida strains isolated from 207 oral candidiasis patients with PCR-RFLP technique. CSH value, total biomass of biofilm and biofilm forming ability of 117 oral Candida isolates were evaluated. C. albicans (61.6%) was still the predominant species in oral candidiasis patients with and without denture wearer, respectively, followed by C. glabrata (15.2%), C. tropicalis (10.4%), C. parapsilosis (3.2%), C. kefyr (3.6%), C. dubliniensis (2%), C. lusitaniae (2%), C. krusei (1.6%), and C. guilliermondii (0.4%). The proportion of mixed colonization with more than one Candida species was 18% from total cases. The relative CSH value and biofilm biomass of NAC species were greater than C. albicans (p<0.001). Ninety-two percent of oral isolates NAC species had biofilm forming ability, whereas 78% of C. albicans were biofilm formers. Furthermore, the significant difference of relative CSH values between biofilm formers and non-biofilm formers was observed in the NAC species (p<0.005), whereas the difference was not statistically significant in C. albicans. The frequency of the NAC species colonization in oral cavity was gradually increasing. The possible contributing factors might be high cell surface hydrophobicity and biofilm forming ability. The relative CSH value could be a putative factor for determining biofilm formation ability of the non-albicans Candida species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Transcript profiling reveals rewiring of iron assimilation gene expression in Candida albicans and C. dubliniensis.

    PubMed

    Moran, Gary P

    2012-12-01

    Hyphal growth is repressed in Candida albicans and Candida dubliniensis by the transcription factor Nrg1. Transcript profiling of a C. dubliniensis NRG1 mutant identified a common group of 28 NRG1-repressed genes in both species, including the hypha-specific genes HWP1, ECE1 and the regulator of cell elongation UME6. Unexpectedly, C. dubliniensis NRG1 was required for wild-type levels of expression of 10 genes required for iron uptake including seven ferric reductases, SIT1, FTR1 and RBT5. However, at alkaline pH and during filamentous growth in 10% serum, most of these genes were highly induced in C. dubliniensis. Conversely, RBT5, PGA10, FRE10 and FRP1 did not exhibit induction during hyphal growth when NRG1 is downregulated, indicating that in C. dubliniensis NRG1 is also required for optimal expression of these genes in alkaline environments. In iron-depleted medium at pH 4.5, reduced growth of the NRG1 mutant relative to wild type was observed; however, growth was restored to wild-type levels or greater at pH 6.5, indicating that alkaline induction of iron assimilation gene expression could rescue this phenotype. These data indicate that transcriptional control of iron assimilation and pseudohypha formation has been separated in C. albicans, perhaps promoting growth in a wider range of niches.

  6. Ultrastructural and biochemical studies of two dynamically expressed cell surface determinants on Candida albicans.

    PubMed Central

    Brawner, D L; Cutler, J E

    1986-01-01

    Variability in the expression of two different cell surface carbohydrate determinants was examined with two agglutinating immunoglobulin M monoclonal antibodies (H9 and C6) and immunoelectron microscopy during growth of three strains of Candida albicans. A single strain of Candida parapsilosis did not express either antigen at any time during growth. Antigens were detected on the surface of C. albicans by agglutination tests with either H9 or C6 over a 48-h growth period. The difference in specificities of the monoclonal antibodies was demonstrated by Ouchterlony double-diffusion tests with solubilized antigens and by variabilities in the reactivity of the agglutinins among yeast strains. The antigenic determinants were isolated by specific immunoprecipitation and protease digestion and characterized by methods including high-pressure liquid chromatography, gas-liquid chromatography, and mass spectroscopy with both chemical and electron ionization. These determinants both contain mannose and glucose. In the case of antigen H9, an additional carbohydrate was detected with gas chromatography and mass spectroscopy. The location of antigens on individual cells was determined by indirect labeling of the determinants, first reacting cells with H9 or C6 followed by goat anti-mouse antibody conjugated with 20-nm colloidal gold particles. Transmission electron microscopy was used to examine cells. The antigens that were reactive with the monoclonal antibodies were associated with a flocculent surface layer. Expression of this layer and expression of the antigens is a dynamic process which is growth phase and strain dependent. The antigens were not expressed on very young cells and disappeared from the cell surface of most C. albicans strains with age. The use of monoclonal antibody to cell surface determinants may allow characterization of cell surface antigens of C. albicans and be helpful in establishing receptors which mediate adherence. Images PMID:3510174

  7. SR-like RNA-binding protein Slr1 affects Candida albicans filamentation and virulence.

    PubMed

    Ariyachet, Chaiyaboot; Solis, Norma V; Liu, Yaoping; Prasadarao, Nemani V; Filler, Scott G; McBride, Anne E

    2013-04-01

    Candida albicans causes both mucosal and disseminated infections, and its capacity to grow as both yeast and hyphae is a key virulence factor. Hyphal formation is a type of polarized growth, and members of the SR (serine-arginine) family of RNA-binding proteins influence polarized growth of both Saccharomyces cerevisiae and Aspergillus nidulans. Therefore, we investigated whether SR-like proteins affect filamentous growth and virulence of C. albicans. BLAST searches with S. cerevisiae SR-like protein Npl3 (ScNpl3) identified two C. albicans proteins: CaNpl3, an apparent ScNpl3 ortholog, and Slr1, another SR-like RNA-binding protein with no close S. cerevisiae ortholog. Whereas ScNpl3 was critical for growth, deletion of NPL3 in C. albicans resulted in few phenotypic changes. In contrast, the slr1Δ/Δ mutant had a reduced growth rate in vitro, decreased filamentation, and impaired capacity to damage epithelial and endothelial cells in vitro. Mice infected intravenously with the slr1Δ/Δ mutant strain had significantly prolonged survival compared to that of mice infected with the wild-type or slr1Δ/Δ mutant complemented with SLR1 (slr1Δ/Δ+SLR1) strain, without a concomitant decrease in kidney fungal burden. Histopathology, however, revealed differential localization of slr1Δ/Δ hyphal and yeast morphologies within the kidney. Mice infected with slr1Δ/Δ cells also had an increased brain fungal burden, which correlated with increased invasion of brain, but not umbilical vein, endothelial cells in vitro. The enhanced brain endothelial cell invasion was likely due to the increased surface exposure of the Als3 adhesin on slr1Δ/Δ cells. Our results indicate that Slr1 is an SR-like protein that influences C. albicans growth, filamentation, host cell interactions, and virulence.

  8. Sap6, a secreted aspartyl proteinase, participates in maintenance the cell surface integrity of Candida albicans

    PubMed Central

    2013-01-01

    Background The polymorphic species Candida albicans is the major cause of candidiasis in humans. The secreted aspartyl proteinases (Saps) of C. albicans, encoded by a family of 10 SAP genes, have been investigated as the virulent factors during candidiasis. However, the biological functions of most Sap proteins are still uncertain. In this study, we applied co-culture system of C. albicans and THP-1 human monocytes to explore the pathogenic roles and biological functions of Sap proteinases. Results After 1 hr of co-culture of C. albicans strains and THP-1 human monocytes at 37°C, more than 60% of the THP-1-engulfed wild type and Δsap5 Candida cells were developing long hyphae. However, about 50% of THP-1-engulfed Δsap6 Candida cells were generating short hyphae, and more dead Candida cells were found in Δsap6 strain that was ingested by THP-1 cells (about 15% in Δsap6 strain vs. 2 ~ 2.5% in SC5314 and Δsap5 strains). The immunofluorescence staining demonstrated that the Sap6 is the major hyphal tip located Sap protein under THP-1 phagocytosis. The sap6-deleted strains (Δsap6, Δsap4/6, and Δsap5/6) appeared slower growth on Congo red containing solid medium at 25°C, and the growth defect was exacerbated when cultured at 37°C in Congo red or SDS containing medium. In addition, more proteins were secreted from Δsap6 strain and the β-mercaptoethanol (β-ME) extractable surface proteins from Δsap6 mutant were more abundant than that of extracted from wild type strain, which included the plasma membrane protein (Pma1p), the ER-chaperone protein (Kar2p), the protein transport-related protein (Arf1p), the cytoskeleton protein (Act1), and the mitochondrial outer membrane protein (porin 1). Moreover, the cell surface accessibility was increased in sap6-deleted strains. Conclusion From these results, we speculated that the cell surface constitution of C. albicans Δsap6 strain was defect. This may cause the more accessible of β-ME to disulfide-bridged cell

  9. Sap6, a secreted aspartyl proteinase, participates in maintenance the cell surface integrity of Candida albicans.

    PubMed

    Buu, Leh-Miauh; Chen, Yee-Chun

    2013-12-30

    The polymorphic species Candida albicans is the major cause of candidiasis in humans. The secreted aspartyl proteinases (Saps) of C. albicans, encoded by a family of 10 SAP genes, have been investigated as the virulent factors during candidiasis. However, the biological functions of most Sap proteins are still uncertain. In this study, we applied co-culture system of C. albicans and THP-1 human monocytes to explore the pathogenic roles and biological functions of Sap proteinases. After 1 hr of co-culture of C. albicans strains and THP-1 human monocytes at 37°C, more than 60% of the THP-1-engulfed wild type and Δsap5 Candida cells were developing long hyphae. However, about 50% of THP-1-engulfed Δsap6 Candida cells were generating short hyphae, and more dead Candida cells were found in Δsap6 strain that was ingested by THP-1 cells (about 15% in Δsap6 strain vs. 2 ~ 2.5% in SC5314 and Δsap5 strains). The immunofluorescence staining demonstrated that the Sap6 is the major hyphal tip located Sap protein under THP-1 phagocytosis. The sap6-deleted strains (Δsap6, Δsap4/6, and Δsap5/6) appeared slower growth on Congo red containing solid medium at 25°C, and the growth defect was exacerbated when cultured at 37°C in Congo red or SDS containing medium. In addition, more proteins were secreted from Δsap6 strain and the β-mercaptoethanol (β-ME) extractable surface proteins from Δsap6 mutant were more abundant than that of extracted from wild type strain, which included the plasma membrane protein (Pma1p), the ER-chaperone protein (Kar2p), the protein transport-related protein (Arf1p), the cytoskeleton protein (Act1), and the mitochondrial outer membrane protein (porin 1). Moreover, the cell surface accessibility was increased in sap6-deleted strains. From these results, we speculated that the cell surface constitution of C. albicans Δsap6 strain was defect. This may cause the more accessible of β-ME to disulfide-bridged cell surface components and may

  10. Investigation of the Function of Candida albicans Als3 by Heterologous Expression in Candida glabrata

    PubMed Central

    Fu, Yue; Phan, Quynh T.; Luo, Guanpingsheng; Solis, Norma V.; Liu, Yaoping; Cormack, Brendan P.; Edwards, John E.; Ibrahim, Ashraf S.

    2013-01-01

    During hematogenously disseminated infection, blood-borne Candida albicans invades the endothelial cell lining of the vasculature to invade the deep tissues. Although the C. albicans Als3 invasin is critical for invasion and damage of endothelial cells in vitro, a C. albicans als3Δ/Δ mutant has normal virulence in the mouse model of disseminated infection. We hypothesized that the contribution of Als3 to virulence is obscured by the presence of additional C. albicans invasins. To elucidate the in vivo function of Als3, we heterologously expressed C. albicans ALS3 in Candida glabrata, a yeast that lacks a close ALS3 ortholog and has low virulence in mice. We found that following intravenous inoculation into mice, the ALS3-expressing strain preferentially trafficked to the brain, where it induced significantly elevated levels of myeloperoxidase, tumor necrosis factor, monocyte chemoattractant protein 1, and gamma interferon. Also, the ALS3-expressing strain had enhanced adherence to and invasion of human brain microvascular endothelial cells in vitro, demonstrating a potential mechanism for ALS3-mediated neurotropism. In addition, upon initiation of infection, the ALS3-expressing strain had increased trafficking to the cortex of the kidneys. With prolonged infection, this strain persisted in the kidneys at significantly higher levels than the control strain but did not induce an elevated inflammatory response. Finally, the ALS3-expressing strain had increased resistance to neutrophil killing in vitro. These results indicate that during disseminated infection, Als3 mediates initial trafficking to the brain and renal cortex and contributes to fungal persistence in the kidneys. PMID:23630968

  11. Efficacy of silver-loaded nanofiber dressings in Candida albicans-contaminated full-skin thickness rat burn wounds.

    PubMed

    Ciloglu, N Sinem; Mert, A Irem; Doğan, Zarife; Demir, Ali; Cevan, Simin; Aksaray, Sebahat; Tercan, Mustafa

    2014-01-01

    In this experimental study, the effects of nanofiber dressings containing different forms of silver on full-thickness rat burn contaminated with Candida albicans was analyzed. A full-thickness skin burn was formed on a total of 32 Sprague-Dawley rats. After the burn wound was seeded with a 10 colony-forming units/ml standard strain of Candida albicans ATCC90028, the animals were divided into four groups. The effects of topical silver sulfadiazine and two recently designed nanofiber dressings containing nanosilver and silversulfadiazine as active materials were compared with the control group. There was a significant difference in the Candida growth on the burn eschar tissue among the groups. The difference for Candida growth in the burn eschar between the control group and the 1% silver sulfadiazine-containing nanofiber dressing group was statistically significant (P< 0.01). Silver sulfadiazine-containing nanofiber dressing was the most effective agent in the treatment of Candida albicans-contaminated burn wounds. Because of their regenerative potential, silver-loaded nanofiber dressings could be a good alternative for infected burn wounds.

  12. The emergence of non-albicans Candida species as causes of invasive candidiasis and candidemia.

    PubMed

    Sobel, Jack D

    2006-11-01

    The last three decades have seen an expanding pool of high-risk patients susceptible to the opportunistic pathogen Candida. Accordingly, a dramatic increase in nosocomial blood stream infections (BSIs) due to Candida spp has been reported throughout the world, starting in tertiary care centers and spreading to community hospitals. This absolute increase in Candida BSIs was accompanied by both an absolute and then a proportional increase in invasive infection caused by reduced fluconazole-susceptible non-albicans Candida spp. Currently, the incidence trend of BSI has stabilized, and Candida albicans remains the most common species causing fungal BSI. Clinicians must be aware of the importance and implications of non-albicans Candida spp when selecting antifungal drugs, although most studies have not shown significant outcome differences with use of the various antifungal classes.

  13. Antifungal effect of Trachyspermum ammi against susceptible and fluconazole-resistant strains of Candida albicans.

    PubMed

    Sharifzadeh, A; Khosravi, A R; Shokri, H; Sharafi, G

    2015-06-01

    Trachyspermum ammi (T. ammi) has been known as having many therapeutic properties and its antimicrobial activity has currently received a renewed interest. This study aimed to verify the effectiveness of T. ammi essential oil to inhibit the growth of Candida albicans (C. albicans) strains isolated from HIV(+) patients with oropharyngeal candidiasis (OPC). The essential oil was obtained by hydrodistillation in a Clevenger apparatus and analyzed by gas chromatography. Susceptibility tests were expressed as inhibition zone by the disk diffusion method and minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) by the broth microdilution method. Thymol (63.4%), p-cymene (19%) and γ-terpinen (16.9%) were found as the most abundant constituents. The disk diffusion results revealed that 67% of oral C. albicans isolates were susceptible, 9% susceptible-dose dependent and 24% resistant to fluconazole. In the broth microdilution method, 68% of isolates were susceptible, 5% susceptible-dose dependent and 27% resistant to fluconazole. The increase in concentration led to a significant reduction in yeasts that were growing in exponential phase. In addition, with increasing in T. ammi oil concentration, the time of remaining cells in lag phase was significantly increased. This study showed that all clinical C. albicans isolates were susceptible to T. ammi essential oil, indicating a significant reduction in the yeast growth in exponential phase. Copyright © 2015. Published by Elsevier Masson SAS.

  14. Evaluation of latex reagents for rapid identification of Candida albicans and C. krusei colonies.

    PubMed Central

    Freydiere, A M; Buchaille, L; Guinet, R; Gille, Y

    1997-01-01

    A total of 322 yeast strains and yeastlike organisms belonging to the genera Candida, Cryptococcus, Geotrichum, Saccharomyces, and Trichosporon were tested with the new monoclonal antibody-based Bichro-latex albicans and Krusei color latex tests. Comparison of results with those obtained by conventional identification methods showed 100% sensitivity for both latex tests and 100% and 95% specificity for the Bichro-latex albicans and Krusei color tests, respectively. Because the test is easy to read and quick to perform, the Bichro-latex albicans test may be useful for rapid identification of Candida albicans colonies in the clinical laboratory. PMID:9157146

  15. Co-occurence of filamentation defects and impaired biofilms in Candida albicans protein kinase mutants.

    PubMed

    Konstantinidou, Nina; Morrissey, John Patrick

    2015-12-01

    Pathogenicity of Candida albicans is linked with its developmental stages, notably the capacity switch from yeast-like to hyphal growth, and to form biofilms on surfaces. To better understand the cellular processes involved in C. albicans development, a collection of 63 C. albicans protein kinase mutants was screened for biofilm formation in a microtitre plate assay. Thirty-eight mutants displayed some degree of biofilm impairment, with 20 categorised as poor biofilm formers. All the poor biofilm formers were also defective in the switch from yeast to hyphae, establishing it as a primary defect. Five genes, VPS15, IME2, PKH3, PGA43 and CEX1, encode proteins not previously reported to influence hyphal development or biofilm formation. Network analysis established that individual components of some processes, most interestingly MAP kinase pathways, are not required for biofilm formation, most likely indicating functional redundancy. Mutants were also screened for their response to bacterial supernatants and it was found that Pseudomonas aeruginosa supernatants inhibited biofilm formation in all mutants, regardless of the presence of homoserine lactones (HSLs). In contrast, Candida morphology was only affected by supernatant containing HSLs. This confirms the distinct HSL-dependent inhibition of filamentation and the HSL-independent impairment of biofilm development by P. aeruginosa. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Adherence of Candida albicans and Candida parapsilosis to epithelial cells correlates with fungal cell surface carbohydrates.

    PubMed

    Lima-Neto, Reginaldo G; Beltrão, Eduardo I C; Oliveira, Patrícia C; Neves, Rejane P

    2011-01-01

    Many studies have described the adherence of Candida albicans to epithelial cells but little is known about Candida parapsilosis adhesion and its role in host cell surface recognition. This study was designed to evaluate the correlation between the adherence of 20 C. albicans and 12 C. parapsilosis strains to human buccal epithelial cells and the expression of fungal cell surface carbohydrates using lectin histochemistry. Adherence assays were carried out by incubating epithelial cells in yeast suspensions (10(7) cells ml(-1) ) and peroxidase conjugated lectins (Con A, WGA, UEA I and PNA at 25 μg ml(-1) ) were used for lectin histochemistry. The results showed that adherence was overall greater for C. albicans than for C. parapsilosis (P < 0.01) and that the individual strain differences correlated with a high content of cell surface α-l-fucose residues as indicated by the UEA I staining pattern. Based on the saccharide specificity of the lectins used, these results suggest that l-fucose residues on cell surface glycoconjugates may represent recognition molecules for interactions between the yeast strain studied and the host (r = 0.6985, P = 0.0045). In addition, our results indicated the presence of α-d-glucose/α-d-mannose, N-acetyl-D-glucosamine/N-acetylneuraminic acid and D-galactose/N-acetyl-D-galactosamine in fungal cell wall.

  17. Experimental hematogenous candidiasis caused by Candida krusei and Candida albicans: species differences in pathogenicity.

    PubMed Central

    Anaissie, E; Hachem, R; K-Tin-U, C; Stephens, L C; Bodey, G P

    1993-01-01

    Hematogenous infections caused by Candida krusei have been noted with increasing frequency, particularly in cancer patients receiving prophylaxis with antifungal triazoles. Progress in understanding the pathogenesis of this emerging infection has been limited by the lack of an animal model. We developed a CF1 mouse intravenous inoculation model of candidiasis to evaluate the pathogenicity of C. krusei in normal and immunosuppressed mice and to compare it with that of Candida albicans. Several inocula (10(6) to 10(8) CFU per animal) of two clinical strains of C. krusei and three American Type Culture Collection strains of C. albicans were tested. Groups of 20 mice each were injected with a single intravenous dose of one inoculum. Animals randomized to receive C. krusei were immunosuppressed by intraperitoneal injection of cyclophosphamide or the combination of cyclophosphamide plus cortisone acetate or they did not receive immunosuppressive agents (normal mice). One hundred percent mortality was observed in normal mice injected with 10(6) CFU of C. albicans per mouse compared with no mortality in normal mice that received 10(8) CFU of C. krusei per mouse (P < 0.01). Resistance to C. krusei infection was markedly lowered by immunosuppression, particularly by the combination of cyclophosphamide plus cortisone acetate, with a significantly shorter survival and a higher organ fungal burden in immunosuppressed than in normal animals (P < 0.01). Tissue infection was documented by culture and histopathologic findings in all examined organs. Images PMID:8454330

  18. Lactobacillus crispatus Modulates Vaginal Epithelial Cell Innate Response to Candida albicans

    PubMed Central

    Niu, Xiao-Xi; Li, Ting; Zhang, Xu; Wang, Su-Xia; Liu, Zhao-Hui

    2017-01-01

    Background: Vulvovaginal candidiasis is caused by Candida albicans. The vaginal epithelium, as the first site of the initial stage of infection by pathogens, plays an important role in resisting genital tract infections. Moreover, lactobacilli are predominant members of the vaginal microbiota that help to maintain a normal vaginal microenvironment. Therefore, Lactobacillus crispatus was explored for its capacity to intervene in the immune response of vaginal epithelial cells VK2/E6E7 to C. albicans. Methods: We examined the interleukin-2 (IL-2), 4, 6, 8, and 17 produced by VK2/E6E7 cells infected with C. albicans and treated with L. crispatus in vitro. The capacity of L. crispatus to adhere to VK2/E6E7 and inhibit C. albicans growth was also tested by scanning electron microscopy (SEM) and adhesion experiments. Results: Compared with group VK2/E6E7 with C. albicans, when treated with L. crispatus, the adhesion of C. albicans to VK2/E6E7 cells decreased significantly by 52.87 ± 1.22%, 47.03 ± 1.35%, and 42.20 ± 1.55% under competition, exclusion, and displacement conditions, respectively. SEM revealed that the invasion of C. albicans into VK2/E6E7 cells was caused by induced endocytosis and active penetration. L. crispatus could effectively protect the cells from the virulence of hyphae and spores of C. albicans and enhance the local immune function of the VK2/E6E7 cells. The concentrations of IL-2, 6, and 17 were upregulated significantly (P < 0.01) and that of IL-8 were downregulated significantly (P < 0.01) in infected VK2/E6E7 cells treated with L. crispatus. The concentration of IL-4 was similar to that of the group VK2/E6E7 with C. albicans (24.10 ± 0.97 vs. 23.12 ± 0.76 pg/ml, P = 0.221). Conclusions: L. crispatus can attenuate the virulence of C. albicans, modulate the secretion of cytokines and chemokines, and enhance the immune response of VK2/E6E7 cells in vitro. The vaginal mucosa has a potential function in the local immune responses against

  19. Effect of tyrosol on adhesion of Candida albicans and Candida glabrata to acrylic surfaces.

    PubMed

    Monteiro, Douglas Roberto; Feresin, Leonardo Perina; Arias, Laís Salomão; Barão, Valentim Adelino Ricardo; Barbosa, Debora Barros; Delbem, Alberto Carlos Botazzo

    2015-09-01

    The prevention of adhesion of Candida cells to acrylic surfaces can be regarded as an alternative to prevent denture stomatitis. The use of quorum sensing molecules, such as tyrosol, could potentially interfere with the adhesion process. Therefore, the aim of this study was to assess the effect of tyrosol on adhesion of single and mixed cultures of Candida albicans and Candida glabrata to acrylic resin surfaces. Tyrosol was diluted in each yeast inoculum (10(7) cells/ml in artificial saliva) at 25, 50, 100, and 200 mM. Then, each dilution was added to wells of 24-well plates containing the acrylic specimens, and the plates were incubated at 37°C for 2 h. After, the effect of tyrosol was determined by total biomass quantification, metabolic activity of the cells and colony-forming unit counting. Chlorhexidine gluconate (CHG) was used as a positive control. Data were analyzed using analysis of variance (ANOVA) and the Holm-Sidak post hoc test (α = 0.05). The results of total biomass quantification and metabolic activity revealed that the tyrosol promoted significant reductions (ranging from 22.32 to 86.16%) on single C. albicans and mixed cultures. Moreover, tyrosol at 200 mM and CHG significantly reduced (p < 0.05) the number of adhered cells to the acrylic surface for single and mixed cultures of both species, with reductions ranging from 1.74 to 3.64-log10. In conclusion, tyrosol has an inhibitory effect on Candida adhesion to acrylic resin, and further investigations are warranted to clarify its potential against Candida infections.

  20. NAD(+)-linked alcohol dehydrogenase 1 regulates methylglyoxal concentration in Candida albicans.

    PubMed

    Kwak, Min-Kyu; Ku, MyungHee; Kang, Sa-Ouk

    2014-04-02

    We purified a fraction that showed NAD(+)-linked methylglyoxal dehydrogenase activity, directly catalyzing methylglyoxal oxidation to pyruvate, which was significantly increased in glutathione-depleted Candida albicans. It also showed NADH-linked methylglyoxal-reducing activity. The fraction was identified as a NAD(+)-linked alcohol dehydrogenase (ADH1) through mass spectrometric analyses. In ADH1-disruptants of both the wild type and glutathione-depleted cells, the intracellular methylglyoxal concentration increased significantly; defects in growth, differentiation, and virulence were observed; and G2-phase arrest was induced.

  1. The Candida genome database incorporates multiple Candida species: multispecies search and analysis tools with curated gene and protein information for Candida albicans and Candida glabrata.

    PubMed

    Inglis, Diane O; Arnaud, Martha B; Binkley, Jonathan; Shah, Prachi; Skrzypek, Marek S; Wymore, Farrell; Binkley, Gail; Miyasato, Stuart R; Simison, Matt; Sherlock, Gavin

    2012-01-01

    The Candida Genome Database (CGD, http://www.candidagenome.org/) is an internet-based resource that provides centralized access to genomic sequence data and manually curated functional information about genes and proteins of the fungal pathogen Candida albicans and other Candida species. As the scope of Candida research, and the number of sequenced strains and related species, has grown in recent years, the need for expanded genomic resources has also grown. To answer this need, CGD has expanded beyond storing data solely for C. albicans, now integrating data from multiple species. Herein we describe the incorporation of this multispecies information, which includes curated gene information and the reference sequence for C. glabrata, as well as orthology relationships that interconnect Locus Summary pages, allowing easy navigation between genes of C. albicans and C. glabrata. These orthology relationships are also used to predict GO annotations of their products. We have also added protein information pages that display domains, structural information and physicochemical properties; bibliographic pages highlighting important topic areas in Candida biology; and a laboratory strain lineage page that describes the lineage of commonly used laboratory strains. All of these data are freely available at http://www.candidagenome.org/. We welcome feedback from the research community at candida-curator@lists.stanford.edu.

  2. Gastrointestinal granuloma due to Candida albicans in an immunocompetent cat

    PubMed Central

    Duchaussoy, Anne-Claire; Rose, Annie; Talbot, Jessica J.; Barrs, Vanessa R.

    2015-01-01

    A 3.5 year-old cat was admitted to the University of Melbourne Veterinary Teaching Hospital for chronic vomiting. Abdominal ultrasonography revealed a focal, circumferential thickening of the wall of the duodenum extending from the pylorus aborally for 3 cm, and an enlarged gastric lymph node. Cytology of fine-needle aspirates of the intestinal mass and lymph node revealed an eosinophilic inflammatory infiltrate and numerous extracellular septate acute angle branching fungal-type hyphae. Occasional hyphae had globose terminal ends, as well as round to oval blastospores and germ tubes. Candida albicans was cultured from a surgical biopsy of the duodenal mass. No underlying host immunodeficiencies were identified. Passage of an abrasive intestinal foreign body was suspected to have caused intestinal mucosal damage resulting in focal intestinal candidiasis. The cat was treated with a short course of oral itraconazole and all clinical signs resolved. PMID:26862475

  3. Cellular Structural Changes in Candida albicans Caused by the Hydroalcoholic Extract from Sapindus saponaria L.

    PubMed

    Shinobu-Mesquita, Cristiane S; Bonfim-Mendonça, Patricia S; Moreira, Amanda L; Ferreira, Izabel C P; Donatti, Lucelia; Fiorini, Adriana; Svidzinski, Terezinha I E

    2015-05-22

    Vulvovaginal candidiasis (VVC) is a disease caused by the abnormal growth of yeast-like fungi in the mucosa of the female genital tract. Candida albicans is the principal etiological agent involved in VVC, but reports have shown an increase in the prevalence of Candida non-C. albicans (CNCA) cases, which complicates VVC treatment because CNCA does not respond well to antifungal therapy. Our group has reported the in vitro antifungal activity of extracts from Sapindus saponaria L. The present study used scanning electron microscopy and transmission electron microscopy to further evaluate the antifungal activity of hydroalcoholic extract from S. saponaria (HE) against yeast obtained from VVC and structural changes induced by HE. We observed the antifungal activity of HE against 125 vaginal yeasts that belonged to four different species of the Candida genus and S. cerevisae. The results suggest that saponins that are present in HE act on the cell wall or membrane of yeast at the first moments after contact, causing damage to these structures and cell lysis.

  4. Virulence modulation of Candida albicans biofilms by metal ions commonly released from orthodontic devices.

    PubMed

    Ronsani, Maiara Medeiros; Mores Rymovicz, Alinne Ulbrich; Meira, Thiago Martins; Trindade Grégio, Ana Maria; Guariza Filho, Odilon; Tanaka, Orlando Motohiro; Ribeiro Rosa, Edvaldo Antonio

    2011-12-01

    The installation of metal devices leads to an increase in the salivary concentration of metal ions and in the growth of salivary Candida spp. However, the relationship between released metal ions and Candida virulence has not been previously examined. The objective of this study was to evaluate whether metal ions affect fungal virulence. We prepared culture media containing Ni(2+), Fe(3+), Cr(3+), Co(2+) or a mixture of these metal ions at concentrations similar to those released in saliva of orthodontic patients. Biofilms of Candida albicans SC5314 were grown for 72 h and their biomasses were determined. The supernatants were analyzed for secretory aspartyl protease (SAP) and hemolysin activities. To verify changes in virulence following treatment with metals, proteolytic and hemolytic activities were converted into specific activities. The results revealed that all ions, except Co(2+), caused increases in biofilm biomass. In addition, Ni(2+) caused an increase in SAP activity and Fe(3+) reduced hemolytic activity. However, the SAP and hemolysin activities in the presence of the mixture of ions did not differ from those of control. These results indicate that metal ions released during the degradation of orthodontic appliances can modulate virulence factors in C. albicans biofilms.

  5. Biophysical Effects of a Polymeric Biosurfactant in Candida krusei and Candida albicans Cells.

    PubMed

    Ferreira, Gabriella Freitas; Dos Santos Pinto, Bruna Lorrana; Souza, Eliene Batista; Viana, José Lima; Zagmignan, Adrielle; Dos Santos, Julliana Ribeiro Alves; Santos, Áquila Rodrigues Costa; Tavares, Priscila Batista; Denadai, Ângelo Márcio Leite; Monteiro, Andrea Souza

    2016-12-01

    This study evaluated the effects of a polymeric biosurfactant produced by Trichosporon montevideense CLOA72 in the adhesion of Candida albicans and Candida krusei cells to human buccal epithelial cells and its interference in biofilm formation by these strains. The biofilm inhibition by biosurfactant (25 mg/mL) in C. krusei and C. albicans in polystyrene was reduced up to 79.5 and 85 %, respectively. In addition, the zeta potential and hydrodynamic diameter of the yeasts altered as a function of the biosurfactant concentration added to the cell suspension. The changes in the cell surface characteristics and the interface modification can contribute to the inhibition of the initial adherence of yeasts cells to the surface. In addition, the analyses of the biofilm matrix and planktonic cell surfaces demonstrated differences in carbohydrate and protein concentrations for the two studied strains, which may contribute to the modulation of cell adhesion or consolidation of biofilms, especially in C. krusei. This study suggests a possible application of the of CLOA72 biosurfactant in inhibiting the adhesion and formation of biofilms on biological surfaces by yeasts of the Candida genus.

  6. Pharmacoeconomic analysis of antifungal therapy for primary treatment of invasive candidiasis caused by Candida albicans and non-albicans Candida species.

    PubMed

    Ou, Huang-Tz; Lee, Tsung-Ying; Chen, Yee-Chun; Charbonneau, Claudie

    2017-07-10

    Cost-effectiveness studies of echinocandins for the treatment of invasive candidiasis, including candidemia, are rare in Asia. No study has determined whether echinocandins are cost-effective for both Candida albicans and non-albicans Candida species. There have been no economic evaluations that compare non-echinocandins with the three available echinocandins. This study was aimed to assess the cost-effectiveness of individual echinocandins, namely caspofungin, micafungin, and anidulafungin, versus non-echinocandins for C. albicans and non-albicans Candida species, respectively. A decision tree model was constructed to assess the cost-effectiveness of echinocandins and non-echinocandins for invasive candidiasis. The probability of treatment success, mortality rate, and adverse drug events were extracted from published clinical trials. The cost variables (i.e., drug acquisition) were based on Taiwan's healthcare system from the perspective of a medical payer. One-way sensitivity analyses and probability sensitivity analyses were conducted. For treating invasive candidiasis (all species), as compared to fluconazole, micafungin and caspofungin are dominated (less effective, more expensive), whereas anidulafungin is cost-effective (more effective, more expensive), costing US$3666.09 for each life-year gained, which was below the implicit threshold of the incremental cost-effectiveness ratio in Taiwan. For C. albicans, echinocandins are cost-saving as compared to non-echinocandins. For non-albicans Candida species, echinocandins are cost-effective as compared to non-echinocandins, costing US$652 for each life-year gained. The results were robust over a wide range of sensitivity analyses and were most sensitive to the clinical efficacy of antifungal treatment. Echinocandins, especially anidulafungin, appear to be cost-effective for invasive candidiasis caused by C. albicans and non-albicans Candida species in Taiwan.

  7. Allyl alcohol and garlic (Allium sativum) extract produce oxidative stress in Candida albicans

    PubMed Central

    Lemar, Katey M.; Passa, Ourania; Aon, Miguel A.; Cortassa, Sonia; Müller, Carsten T.; Plummer, Sue; O’Rourke, Brian; Lloyd, David

    2009-01-01

    Both the growth and respiration of Candida albicans are sensitive to extracts of Allium sativum and investigations into the anticandidal activities are now focussing on the purified constituents to determine the targets of inhibition. Of particular interest is allyl alcohol (AA), a metabolic product that accumulates after trituration of garlic cloves. Putative targets for AA were investigated by monitoring changes in intracellular responses after exposure of C. albicans cells to AA or a commercially available garlic extract. Two-photon laser scanning microscopy and other techniques were used. Changes typical of oxidative stress – NADH oxidation and glutathione depletion, and increased reactive oxygen species – were observed microscopically and by flow cytometry. Known targets for AA are alcohol dehydrogenases Adh1 and 2 (in the cytosol) and Adh3 (mitochondrial), although the significant decrease in NAD(P)H after addition of AA is indicative of another mechanism of action. PMID:16207909

  8. Mode of Action of the Polyene Antibiotic Candicidin: Binding Factors in the Wall of Candida albicans

    PubMed Central

    Hammond, S. M.; Kliger, B. N.

    1976-01-01

    The polyene antibiotic candicidin produces a rapid efflux of K+ ions from a suspension of Candida albicans. Onset of K+ leakage depends on the culture age, stationary-phase yeasts leaking K+ more slowly than exponential-phase yeasts. The time taken for potassium leakage to begin represents the time taken by the antibiotic to cross the cell wall and produce membrane damage. It was shown that there were factors in the cell wall of C. albicans that increased their total binding capacity and their affinity for candicidin during growth. An attempt was made to relate changes in the lipid content of the yeast cell with the increased time taken to produce membrane damage. PMID:773298

  9. Contribution of VMA5 to vacuolar function, stress response, ion homeostasis and autophagy in Candida albicans.

    PubMed

    Zhang, Kai; Jia, Chang; Yu, Qilin; Xiao, Chenpeng; Dong, Yijie; Zhang, Meng; Zhang, Dan; Zhao, Qiang; Zhang, Biao; Li, Mingchun

    2017-09-07

    V-ATPase is a conservative multi-subunit enzyme in eukaryotes and modulates several cellular responses. This study aimed to illustrate the roles of Vma5 in vacuolar function, oxidative stress response, calcium homeostasis, autophagy and virulence. The vma5Δ/Δ mutant was obtained using PCR-mediated homologous recombination. The functions of Vma5 were investigated by a series of biochemical and systemic infection methods. Disruption of VMA5 led to growth inhibition, vacuolar dysfunction, disturbance of calcium homeostasis and inhibition of calcium-related oxidative stress response. Furthermore, its deletion caused defects in autophagy completion and hyphal development, and resulted in attenuated Candida albicans virulence. Our findings provide new insights into V-ATPase functions in C. albicans, and reveal a potential candidate for development of antifungal drugs.

  10. Contact-induced apical asymmetry drives the thigmotropic responses of Candida albicans hyphae

    PubMed Central

    Thomson, Darren D; Wehmeier, Silvia; Byfield, FitzRoy J; Janmey, Paul A; Caballero-Lima, David; Crossley, Alison; Brand, Alexandra C

    2015-01-01

    Filamentous hyphae of the human pathogen, Candida albicans, invade mucosal layers and medical silicones. In vitro, hyphal tips reorient thigmotropically on contact with small obstacles. It is not known how surface topography is sensed but hyphae lacking the cortical marker, Rsr1/Bud1, are unresponsive. We show that, on surfaces, the morphology of hyphal tips and the position of internal polarity protein complexes are asymmetrically skewed towards the substratum and biased towards the softer of two surfaces. In nano-fabricated chambers, the Spitzenkörper (Spk) responded to touch by translocating across the apex towards the point of contact, where its stable maintenance correlated with contour-following growth. In the rsr1Δ mutant, the position of the Spk meandered and these responses were attenuated. Perpendicular collision caused lateral Spk oscillation within the tip until after establishment of a new growth axis, suggesting Spk position does not predict the direction of growth in C. albicans. Acute tip reorientation occurred only in cells where forward growth was countered by hyphal friction sufficient to generate a tip force of ∼ 8.7 μN (1.2 MPa), more than that required to penetrate host cell membranes. These findings suggest mechanisms through which the organization of hyphal tip growth in C. albicans facilitates the probing, penetration and invasion of host tissue. PMID:25262778

  11. Contact-induced apical asymmetry drives the thigmotropic responses of Candida albicans hyphae.

    PubMed

    Thomson, Darren D; Wehmeier, Silvia; Byfield, FitzRoy J; Janmey, Paul A; Caballero-Lima, David; Crossley, Alison; Brand, Alexandra C

    2015-03-01

    Filamentous hyphae of the human pathogen, Candida albicans, invade mucosal layers and medical silicones. In vitro, hyphal tips reorient thigmotropically on contact with small obstacles. It is not known how surface topography is sensed but hyphae lacking the cortical marker, Rsr1/Bud1, are unresponsive. We show that, on surfaces, the morphology of hyphal tips and the position of internal polarity protein complexes are asymmetrically skewed towards the substratum and biased towards the softer of two surfaces. In nano-fabricated chambers, the Spitzenkörper (Spk) responded to touch by translocating across the apex towards the point of contact, where its stable maintenance correlated with contour-following growth. In the rsr1Δ mutant, the position of the Spk meandered and these responses were attenuated. Perpendicular collision caused lateral Spk oscillation within the tip until after establishment of a new growth axis, suggesting Spk position does not predict the direction of growth in C. albicans. Acute tip reorientation occurred only in cells where forward growth was countered by hyphal friction sufficient to generate a tip force of ∼ 8.7 μN (1.2 MPa), more than that required to penetrate host cell membranes. These findings suggest mechanisms through which the organization of hyphal tip growth in C. albicans facilitates the probing, penetration and invasion of host tissue. © 2014 The Authors. Cellular Microbiology published by John Wiley & Sons Ltd.

  12. Candida albicans stimulates Streptococcus mutans microcolony development via cross-kingdom biofilm-derived metabolites

    PubMed Central

    Kim, Dongyeop; Sengupta, Arjun; Niepa, Tagbo H. R.; Lee, Byung-Hoo; Weljie, Aalim; Freitas-Blanco, Veronica S.; Murata, Ramiro M.; Stebe, Kathleen J.; Lee, Daeyeon; Koo, Hyun

    2017-01-01

    Candida albicans is frequently detected with heavy infection of Streptococcus mutans in plaque-biofilms from children affected with early-childhood caries, a prevalent and costly oral disease. The presence of C. albicans enhances S. mutans growth within biofilms, yet the chemical interactions associated with bacterial accumulation remain unclear. Thus, this study was conducted to investigate how microbial products from this cross-kingdom association modulate S. mutans build-up in biofilms. Our data revealed that bacterial-fungal derived conditioned medium (BF-CM) significantly increased the growth of S. mutans and altered biofilm 3D-architecture in a dose-dependent manner, resulting in enlarged and densely packed bacterial cell-clusters (microcolonies). Intriguingly, BF-CM induced S. mutans gtfBC expression (responsible for Gtf exoenzymes production), enhancing Gtf activity essential for microcolony development. Using a recently developed nanoculture system, the data demonstrated simultaneous microcolony growth and gtfB activation in situ by BF-CM. Further metabolites/chromatographic analyses of BF-CM revealed elevated amounts of formate and the presence of Candida-derived farnesol, which is commonly known to exhibit antibacterial activity. Unexpectedly, at the levels detected (25–50 μM), farnesol enhanced S. mutans-biofilm cell growth, microcolony development, and Gtf activity akin to BF-CM bioactivity. Altogether, the data provide new insights on how extracellular microbial products from cross-kingdom interactions stimulate the accumulation of a bacterial pathogen within biofilms. PMID:28134351

  13. MIG1 Regulates Resistance of Candida albicans