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Sample records for candida albicans growth

  1. 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.

  2. 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. PMID:24224742

  3. Three prevacuolar compartment Rab GTPases impact Candida albicans hyphal growth.

    PubMed

    Johnston, Douglas A; Tapia, Arturo Luna; Eberle, Karen E; Palmer, Glen E

    2013-07-01

    Disruption of vacuolar biogenesis in the pathogenic yeast Candida albicans causes profound defects in polarized hyphal growth. However, the precise vacuolar pathways involved in yeast-hypha differentiation have not been determined. Previously we focused on Vps21p, a Rab GTPase involved in directing vacuolar trafficking through the late endosomal prevacuolar compartment (PVC). Herein, we identify two additional Vps21p-related GTPases, Ypt52p and Ypt53p, that colocalize with Vps21p and can suppress the hyphal defects of the vps21Δ/Δ mutant. Phenotypic analysis of gene deletion strains revealed that loss of both VPS21 and YPT52 causes synthetic defects in endocytic trafficking to the vacuole, as well as delivery of the virulence-associated vacuolar membrane protein Mlt1p from the Golgi compartment. Transcription of all three GTPase-encoding genes is increased under hyphal growth conditions, and overexpression of the transcription factor Ume6p is sufficient to increase the transcription of these genes. While only the vps21Δ/Δ single mutant has hyphal growth defects, these were greatly exacerbated in a vps21Δ/Δ ypt52Δ/Δ double mutant. On the basis of relative expression levels and phenotypic analysis of gene deletion strains, Vps21p is the most important of the three GTPases, followed by Ypt52p, while Ypt53p has an only marginal impact on C. albicans physiology. Finally, disruption of a nonendosomal AP-3-dependent vacuolar trafficking pathway in the vps21Δ/Δ ypt52Δ/Δ mutant, further exacerbated the stress and hyphal growth defects. These findings underscore the importance of membrane trafficking through the PVC in sustaining the invasive hyphal growth form of C. albicans.

  4. Bacterial peptidoglycan-derived molecules activate Candida albicans hyphal growth.

    PubMed

    Wang, Yue; Xu, Xiao-Li

    2008-01-01

    Serum strongly induces the yeast-to-hypha growth transition in the human fungal pathogen Candida albicans, playing an important role in infection. However, identity of the serum inducer(s) and its sensor remain poorly defined. We used NMR to analyze the chromatographic serum fractionations enriched for the hypha-inducing activity and found structures resembling subunits of bacterial peptidoglycan (PGN). We then confirmed that several purified and synthetic muramyl dipeptides (MDPs), subunits of PGN, can indeed strongly promote C. albicans hyphal growth. Taking cue from the recognition of MDPs by the mammalian bacterial sensor Nod2 using its leucine-rich-repeat (LRR) domain, we discovered that MDPs activate the adenylyl cyclase Cyr1 by binding to its LRR domain. The cAMP/PKA signaling pathway is well known to control hyphal morphogenesis and other infection-related traits. Given the abundance of PGN at the large intestinal epithelial surface, a natural habitat and invasion site for C. albcians, our findings have important implications in the mechanisms of infection by this pathogen. PMID:19704871

  5. Bacterial peptidoglycan-derived molecules activate Candida albicans hyphal growth

    PubMed Central

    Xu, Xiao-Li

    2008-01-01

    Serum strongly induces the yeast-to-hypha growth transition in the human fungal pathogen Candida albicans, playing an important role in infection. However, identity of the serum inducer(s) and its sensor remain poorly defined. We used NMR to analyze the chromatographic serum fractionations enriched for the hypha-inducing activity and found structures resembling subunits of bacterial peptidoglycan (PGN). We then confirmed that several purified and synthetic muramyl dipeptides (MDPs), subunits of PGN, can indeed strongly promote C. albicans hyphal growth. Taking cue from the recognition of MDPs by the mammalian bacterial sensor Nod2 using its leucine-rich-repeat (LRR) domain, we discovered that MDPs activate the adenylyl cyclase Cyr1 by binding to its LRR domain. The cAMP/PKA signaling pathway is well known to control hyphal morphogenesis and other infection-related traits. Given the abundance of PGN at the large intestinal epithelial surface, a natural habitat and invasion site for C. albcians, our findings have important implications in the mechanisms of infection by this pathogen. PMID:19704871

  6. Improved gene ontology annotation for biofilm formation, filamentous growth, and phenotypic switching in Candida albicans.

    PubMed

    Inglis, Diane O; Skrzypek, Marek S; Arnaud, Martha B; Binkley, Jonathan; Shah, Prachi; Wymore, Farrell; Sherlock, Gavin

    2013-01-01

    The opportunistic fungal pathogen Candida albicans is a significant medical threat, especially for immunocompromised patients. Experimental research has focused on specific areas of C. albicans biology, with the goal of understanding the multiple factors that contribute to its pathogenic potential. Some of these factors include cell adhesion, invasive or filamentous growth, and the formation of drug-resistant biofilms. The Gene Ontology (GO) (www.geneontology.org) is a standardized vocabulary that the Candida Genome Database (CGD) (www.candidagenome.org) and other groups use to describe the functions of gene products. To improve the breadth and accuracy of pathogenicity-related gene product descriptions and to facilitate the description of as yet uncharacterized but potentially pathogenicity-related genes in Candida species, CGD undertook a three-part project: first, the addition of terms to the biological process branch of the GO to improve the description of fungus-related processes; second, manual recuration of gene product annotations in CGD to use the improved GO vocabulary; and third, computational ortholog-based transfer of GO annotations from experimentally characterized gene products, using these new terms, to uncharacterized orthologs in other Candida species. Through genome annotation and analysis, we identified candidate pathogenicity genes in seven non-C. albicans Candida species and in one additional C. albicans strain, WO-1. We also defined a set of C. albicans genes at the intersection of biofilm formation, filamentous growth, pathogenesis, and phenotypic switching of this opportunistic fungal pathogen, which provides a compelling list of candidates for further experimentation.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26195510

  8. 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.

  9. 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.

  10. In vitro effects of glycyrrhetinic acid on the growth of clinical isolates of Candida albicans.

    PubMed

    Pellati, Donatella; Fiore, Cristina; Armanini, Decio; Rassu, Mario; Bertoloni, Giulio

    2009-04-01

    Compounds derived from Glycyrrhiza glabra L. root have been used widely for centuries for their numerous therapeutic properties. The present study aimed to test the in vitro activity against Candida albicans strains of the compound 18-beta glycyrrhetinic acid (18-beta GA), derived from the root of Glycyrrhiza species. This antimicrobial activity was assessed using the National Committee for Clinical Laboratory Standards (NCCLS) method on C. albicans strains that were isolated from patients with recurrent vulvovaginal candidiasis (RVVC). The in vitro growth of the C. albicans strains was markedly reduced, in a pH-dependent manner, by relatively low doses (6.2 microg/mL) of 18-beta GA. The results demonstrate that 18-beta GA is a promising biological alternative for the topical treatment of recurrent vulvovaginal candidiasis (RVVC). PMID:19067381

  11. 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

  12. 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.

  13. 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.

  14. Effect of nonylphenol on growth of Neurospora crassa and Candida albicans.

    PubMed

    Karley, A J; Powell, S I; Davies, J M

    1997-04-01

    The effects of the nonionic surfactant nonylphenol on the growth and morphologies of the filamentous fungus Neurospora crassa and the diploid yeast Candida albicans have been examined. Nonylphenol inhibited respiration and growth of N. crassa, effecting a 10-fold decrease in organism yield at 25 microM. Severe morphological defects were also induced: cell shape was abnormal and apical dominance was lost. Nonylphenol monoethoxylate (the parent compound of nonylphenol) was a less potent growth inhibitor and morphogen. The growth of the yeast form of C. albicans was sensitive to nonylphenol (inducing an order of magnitude decrease in specific growth rate with a 10-fold increase in dose concentration) but not nonylphenol monoethoxylate. Similarly, C. albicans ATP content was reduced and glucose-induced extracellular acidification was inhibited only by nonylphenol. Although estrogens may induce the dimorphic transition of C. albicans, nonylphenol (as an environmental estrogen mimic) failed to trigger germ tube formation under nonpermissive conditions and inhibited it under permissive conditions. The effects of nonylphenol are most readily explained as the result of uncoupling of respiration, which produces multiple physiological effects.

  15. Quinacrine inhibits Candida albicans growth and filamentation at neutral pH.

    PubMed

    Kulkarny, Vibhati V; Chavez-Dozal, Alba; Rane, Hallie S; Jahng, Maximillian; Bernardo, Stella M; Parra, Karlett J; Lee, Samuel A

    2014-12-01

    Candida albicans is a common cause of catheter-related bloodstream infections (CR-BSI), in part due to its strong propensity to form biofilms. Drug repurposing is an approach that might identify agents that are able to overcome antifungal drug resistance within biofilms. Quinacrine (QNC) is clinically active against the eukaryotic protozoan parasites Plasmodium and Giardia. We sought to investigate the antifungal activity of QNC against C. albicans biofilms. C. albicans biofilms were incubated with QNC at serially increasing concentrations (4 to 2,048 μg/ml) and assessed using a 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay in a static microplate model. Combinations of QNC and standard antifungals were assayed using biofilm checkerboard analyses. To define a mechanism of action, QNC was assessed for the inhibition of filamentation, effects on endocytosis, and pH-dependent activity. High-dose QNC was effective for the prevention and treatment of C. albicans biofilms in vitro. QNC with fluconazole had no interaction, while the combination of QNC and either caspofungin or amphotericin B demonstrated synergy. QNC was most active against planktonic growth at alkaline pH. QNC dramatically inhibited filamentation. QNC accumulated within vacuoles as expected and caused defects in endocytosis. A tetracycline-regulated VMA3 mutant lacking vacuolar ATPase (V-ATPase) function demonstrated increased susceptibility to QNC. These experiments indicate that QNC is active against C. albicans growth in a pH-dependent manner. Although QNC activity is not biofilm specific, QNC is effective in the prevention and treatment of biofilms. QNC antibiofilm activity likely occurs via several independent mechanisms: vacuolar alkalinization, inhibition of endocytosis, and impaired filamentation. Further investigation of QNC for the treatment and prevention of biofilm-related Candida CR-BSI is warranted. PMID:25288082

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

    PubMed

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

    2013-12-01

    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

  17. The Ess1 prolyl isomerase is required for growth and morphogenetic switching in Candida albicans.

    PubMed Central

    Devasahayam, Gina; Chaturvedi, Vishnu; Hanes, Steven D

    2002-01-01

    Prolyl-isomerases (PPIases) are found in all organisms and are important for the folding and activity of many proteins. Of the 13 PPIases in Saccharomyces cerevisiae only Ess1, a parvulin-class PPIase, is essential for growth. Ess1 is required to complete mitosis, and Ess1 and its mammalian homolog, Pin1, interact directly with RNA polymerase II. Here, we isolate the ESS1 gene from the pathogenic fungus Candida albicans and show that it is functionally homologous to the S. cerevisiae ESS1. We generate conditional-lethal (ts) alleles of C. albicans ESS1 and use these mutations to demonstrate that ESS1 is essential for growth in C. albicans. We also show that reducing the dosage or activity of ESS1 blocks morphogenetic switching from the yeast to the hyphal and pseudohyphal forms under certain conditions. Analysis of double mutants of ESS1 and TUP1 or CPH1, two genes known to be involved in morphogenetic switching, suggests that ESS1 functions in the same pathway as CPH1 and upstream of or in parallel to TUP1. Given that switching is important for virulence of C. albicans, inhibitors of Ess1 might be useful as antifungal agents. PMID:11805043

  18. A Candida albicans Strain Expressing Mammalian Interleukin-17A Results in Early Control of Fungal Growth during Disseminated Infection

    PubMed Central

    Huppler, Anna R.; Whibley, Natasha; Woolford, Carol A.; Childs, Erin E.; He, Jie; Biswas, Partha S.; McGeachy, Mandy J.; Mitchell, Aaron P.

    2015-01-01

    Candida albicans is normally a commensal fungus of the human mucosae and skin, but it causes life-threatening systemic infections in hospital settings in the face of predisposing conditions, such as indwelling catheters, abdominal surgery, or antibiotic use. Immunity to C. albicans involves various immune parameters, but the cytokine interleukin-17A (IL-17A) (also known as IL-17) has emerged as a centrally important mediator of immune defense against both mucosal and systemic candidiasis. Conversely, IL-17A has been suggested to enhance the virulence of C. albicans, indicating that it may exert detrimental effects on pathogenesis. In this study, we hypothesized that a C. albicans strain expressing IL-17A would exhibit reduced virulence in vivo. To that end, we created a Candida-optimized expression cassette encoding murine IL-17A, which was transformed into the DAY286 strain of C. albicans. Candida-derived IL-17A was indistinguishable from murine IL-17A in terms of biological activity and detection in standard enzyme-linked immunosorbent assays (ELISAs). Expression of IL-17A did not negatively impact the growth of these strains in vitro. Moreover, the IL-17A-expressing C. albicans strains showed significantly reduced pathogenicity in a systemic model of Candida infection, mainly evident during the early stages of disease. Collectively, these findings suggest that IL-17A mitigates the virulence of C. albicans. PMID:26150537

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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. PMID:27087525

  4. 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

  5. The inhibitory activity of linalool against the filamentous growth and biofilm formation in Candida albicans.

    PubMed

    Hsu, Chih-Chieh; Lai, Wen-Lin; Chuang, Kuei-Chin; Lee, Meng-Hwan; Tsai, Ying-Chieh

    2013-07-01

    Candida spp. are part of the natural human microbiota, but they also represent important opportunistic human pathogens. Biofilm-associated Candida albicans infections are clinically relevant due to their high levels of resistance to traditional antifungal agents. In this study, we investigated the ability of linalool to inhibit the formation of C. albicans biofilms and reduce existing C. albicans biofilms. Linalool exhibited antifungal activity against C. albicans ATCC 14053, with a minimum inhibitory concentration (MIC) of 8 mM. Sub-MIC concentrations of linalool also inhibited the formation of germ tubes and biofilms in that strain. The defective architecture composition of C. albicans biofilms exposed to linalool was characterized by scanning electron microscopy. The expression levels of the adhesin genes HWP1 and ALS3 were downregulated by linalool, as assessed by real-time RT-PCR. The expression levels of CYR1 and CPH1, which encode components of the cAMP-PKA and MAPK hyphal formation regulatory pathways, respectively, were also suppressed by linalool, as was the gene encoding their upstream regulator, Ras1. The expression levels of long-term hyphae maintenance associated genes, including UME6, HGC1, and EED1, were all suppressed by linalool. These results indicate that linalool may have therapeutic potential in the treatment of candidiasis associated with medical devices because it interferes with the morphological switch and biofilm formation of C. albicans.

  6. 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.

  7. Acetate-mediated growth inhibition in sterol 14alpha-demethylation-deficient cells of Candida albicans.

    PubMed

    Shimokawa, O; Nakayama, H

    1999-01-01

    Candida albicans is a fungus thought to be viable in the presence of a deficiency in sterol 14alpha-demethylation. We showed in a strain of this species that the deficiency, caused either by a mutation or by an azole antifungal agent, made the cells susceptible to growth inhibition by acetate included in the culture medium. Studies with a mutant demonstrated that the inhibition was complete at a sodium acetate concentration of 0.24 M (20 g/liter) and was evident even at a pH of 8, the latter result indicating the involvement of acetate ions rather than the undissociated form of acetic acid. In fluconazole-treated cells, sterol profiles determined by thin-layer chromatography revealed that the minimum sterol 14alpha-demethylation-inhibitory concentrations (MDICs) of the drug, thought to be the most important parameter for clinical purposes, were practically identical in the media with and without 0.24 M acetate and were equivalent to the MIC in the acetate-supplemented medium. The acetate-mediated growth inhibition of azole-treated cells was confirmed with two additional strains of C. albicans and four different agents, suggesting the possibility of generalization. From these results, it was surmised that the acetate-containing medium may find use in azole susceptibility testing, for which there is currently no method capable of measuring MDICs directly for those fungi whose viability is not lost as a result of sterol 14alpha-demethylation deficiency. Additionally, the acetate-supplemented agar medium was found to be useful in detecting reversions from sterol 14alpha-demethylation deficiency to proficiency. PMID:9869573

  8. 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.

  9. Inhibitory activity of hydrosols, herbal teas and related essential oils against filament formation and the growth of Candida albicans.

    PubMed

    Inouye, Shigeharu; Takahashi, Miki; Abe, Shigeru

    2009-01-01

    The antifungal activity of 43 hydrosols, 7 herbal teas and 12 essential oils was determined using Candida albicans as a test organism. All of the hydrosols examined showed more potent inhibition against the filamentous form than the yeast form of C. albicans. In particular, the filamentous form was markedly inhibited by seven hydrosols, of which monarda, santolina and clove water also inhibited the growth of the yeast form. Most of the inhibitory activity of the hydrosols was correlated with that of their respective major components. Poor correlation was observed between the inhibition of filament formation and the growth inhibition of the yeast form among the hydrosols examined, among essential oils and among the major components of hydrosols and essential oils. Seven herbal teas showed moderate or weak activity against the filament formation of C. albicans, but no inhibition against the yeast form.

  10. 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.

  11. 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

  12. 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.

  13. 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

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

    PubMed

    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, K i 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

  15. 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

  16. Candida albicans Biofilms and Human Disease.

    PubMed

    Nobile, Clarissa J; Johnson, Alexander D

    2015-01-01

    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

  17. Candida albicans escapes from mouse neutrophils.

    PubMed

    Ermert, David; Niemiec, Maria J; Röhm, Marc; Glenthøj, Andreas; Borregaard, Niels; Urban, Constantin F

    2013-08-01

    Candida albicans, the most commonly isolated human fungal pathogen, is able to grow as budding yeasts or filamentous forms, such as hyphae. The ability to switch morphology has been attributed a crucial role for the pathogenesis of C. albicans. To mimic disseminated candidiasis in humans, the mouse is the most widely used model organism. Neutrophils are essential immune cells to prevent opportunistic mycoses. To explore potential differences between the rodent infection model and the human host, we compared the interactions of C. albicans with neutrophil granulocytes from mice and humans. We revealed that murine neutrophils exhibited a significantly lower ability to kill C. albicans than their human counterparts. Strikingly, C. albicans yeast cells formed germ tubes upon internalization by murine neutrophils, eventually rupturing the neutrophil membrane and thereby, killing the phagocyte. On the contrary, growth and subsequent escape of C. albicans are blocked inside human neutrophils. According to our findings, this blockage in human neutrophils might be a result of higher levels of MPO activity and the presence of α-defensins. We therefore outline differences in antifungal immune defense between humans and mouse strains, which facilitates a more accurate interpretation of in vivo results.

  18. Disruption of homocitrate synthase genes in Candida albicans affects growth but not virulence.

    PubMed

    Kur, Krzysztof; Gabriel, Iwona; Morschhäuser, Joachim; Barchiesi, Francesco; Spreghini, Elisabetta; Milewski, Sławomir

    2010-12-01

    Two genes, LYS21 and LYS22, encoding isoforms of homocitrate synthase, an enzyme catalysing the first committed step in the lysine biosynthetic pathway, were disrupted in Candida albicans using the SAT1 flipper strategy. The double null lys21Δ/lys22Δ mutant lacked homocitrate synthase activity and exhibited lysine auxotrophy in minimal media that could be fully rescued by the addition of 0.5-0.6 mM L: -lysine. On the other hand, its virulence in vivo in the model of disseminated murine candidiasis appeared identical to that of the mother, wild-type strain. These findings strongly question a possibility of exploitation of homocitrate synthase and possibly also other enzymes of the lysine biosynthetic pathway as targets in chemotherapy of disseminated fungal infections.

  19. Bifidobacterium longum-fermented broccoli supernatant inhibited the growth of Candida albicans and some pathogenic bacteria in vitro.

    PubMed

    Suido, Hirohisa; Miyao, Manabu

    2008-06-01

    The aim of this study is to develop a growth inhibitory material against some pathogenic microorganisms, using beneficial bacteria such as Bifidobacterium species and certain types of vegetables which can be good substrates for the growth of the beneficial bacteria. At first, various vegetable juices were screened for the growth promotion of Bifidobacterium longum etc. Among the vegetables tested, broccoli (Brassica oleracea L. var. botrytis L.) and cabbage (Brassica oleracea L. var. capitata L.) showed excellent growth promoting activities for B. longum. Secondly, the B. longum-fermented broccoli (BFB) and Lactobacillus pentosus-fermented broccoli (LFB) supernatants were prepared and the growth inhibitory activities against Candida albicans were determined. Both of them showed dose-dependent, growth inhibitory effects, and the effect of BFB was superior to LFB. It was thought that the superior effect of BFB could be mainly attributed to the acids, especially acetic acid, produced by B. longum. BFB also inhibited some pathogenic bacteria such as Streptococcus mutans and Porphylomonas gingivalis. In conclusion, broccoli was found to be a good growth-promoting substance for B. longum. The fermented product, BFB, appears to be a usable material that inhibits the growth of C. albicans and some pathogenic bacteria. PMID:18661679

  20. 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.

  1. 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

  2. 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

  3. 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

  4. Small molecules inhibit growth, viability and ergosterol biosynthesis in Candida albicans.

    PubMed

    Rajput, Sandeep B; Karuppayil, S Mohan

    2013-12-01

    The aim of this work was to evaluate the anti-Candida efficacy of twenty five molecules of plant origin. Based on their MICs, effective molecules were categorized into four categories. Susceptibility testing of test compounds was carried out by standard methodology (M27-A2) as per CLSI guidelines. Minimum Fungicidal Concentration (MFC) was determined as the lowest concentration of drug killing 99.9% cells. Effect on sterol profile was evaluated by sterol quantitation method. Among the screened molecules, cinnamaldehyde, piperidine, citral, furfuraldehyde and indole were potent inhibitors of growth and viability. Exposure of Candida cells to cinnamaldehyde, piperidine, citral, furfuraldehyde, indole, α- and β- pinene at MIC's, altered ergosterol profile. Our results indicate that the molecules altering sterol profile may exert their antifungal effect through inhibition of ergosterol biosynthesis and could be good candidates for fungal specific drug development. PMID:23449869

  5. In vitro modification of Candida albicans invasiveness.

    PubMed

    Fontenla de Petrino, S E; de Jorrat, M E; Sirena, A; Valdez, J C; Mesón, O

    1986-05-01

    Candida albicans produces germ-tubes (GT) when it is incubated in animal or human serum. This dimorphism is responsible for its invasive ability. The purpose of the present paper is (1) to evaluate the ability of rat peritoneal macrophages to inhibit GT production of ingested Candida albicans, obtained from immunized rats and then activated in vitro with Candida-induced lymphokines; (2) to determinate any possible alteration of phagocytic and candidacidal activities. The phagocytes were obtained from rats immunized with viable C. albicans. Some of them were exposed to Candida-induced lymphokines in order to activate the macrophages in vitro. The monolayers of activated, immune and normal macrophages were infected with a C. albicans suspension during 4 hr. Activated macrophages presented not only the highest phagocytic and candidacidal activities but a noticeable inhibition of GT formation and incremented candidacidal activity.

  6. In vitro modification of Candida albicans invasiveness.

    PubMed

    Fontenla de Petrino, S E; de Jorrat, M E; Sirena, A; Valdez, J C; Mesón, O

    1986-05-01

    Candida albicans produces germ-tubes (GT) when it is incubated in animal or human serum. This dimorphism is responsible for its invasive ability. The purpose of the present paper is (1) to evaluate the ability of rat peritoneal macrophages to inhibit GT production of ingested Candida albicans, obtained from immunized rats and then activated in vitro with Candida-induced lymphokines; (2) to determinate any possible alteration of phagocytic and candidacidal activities. The phagocytes were obtained from rats immunized with viable C. albicans. Some of them were exposed to Candida-induced lymphokines in order to activate the macrophages in vitro. The monolayers of activated, immune and normal macrophages were infected with a C. albicans suspension during 4 hr. Activated macrophages presented not only the highest phagocytic and candidacidal activities but a noticeable inhibition of GT formation and incremented candidacidal activity. PMID:3523254

  7. GENETIC CONTROL OF CANDIDA ALBICANS BIOFILM DEVELOPMENT

    PubMed Central

    Finkel, Jonathan S.; Mitchell, Aaron P.

    2014-01-01

    Preface Candida species cause frequent infections due to their ability to form biofilms – surface-associated microbial communities – primarily on implanted medical devices. Increasingly, mechanistic studies have identified the gene products that participate directly in Candida albicans biofilm formation, as well as the regulatory circuitry and networks that control their expression and activity. These studies have revealed new mechanisms and signals that govern C. albicans biofilm formation and associated drug resistance, thus providing biological insight and therapeutic foresight. PMID:21189476

  8. 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.

  9. Commercial and Plant Extract Denture Cleansers in Prevention of Candida albicans Growth on Soft Denture Reliner: In Vitro Study

    PubMed Central

    Dhaded, Sunil; Joshi, Shalini

    2016-01-01

    Objective To evaluate and compare the efficacy of two plant extracts and two commercially available denture cleansers against candida albicans adherent to soft denture reline material. Materials and Methods In this study 60 specimens of soft denture reliner material specimens were fabricated with dimensions 10x10x2 mm. The sterile specimens were inoculated by immersion in Sabourand broth containing Candida albicans for 16 hours at 37°C in an incubator. Then the specimens were washed and immersed in denture cleansers which were divided into group five groups from Group I-V for CD Clean®, Nigella sativa, thyme essential oil, Fittydent® and distilled water respectively, for 8 hours at room temperature. Then they were washed, fixed with methanol and stained with crystal violet. Candida cells adherent to the specimens were counted under microscope. The number of cells adherent to test samples were compared with that adherent to control. Results The effectiveness of Fittydent® was more than CD Clean® in reducing the adherent candida albicans and the difference was statically significant (p = <0.001). Both thyme essential oil and nigella sativa were almost same in effectiveness against candida albicans but the difference was not statically significant (p= 0.79). Post-hoc Tukey’s test was performed which indicated that Fittydent® was the most effective amongst the denture cleansers tested in this study, followed by thyme essential oil, nigella sativa and CD Clean®. Conclusion The results of the study showed that all denture cleansers used in the study were significantly effective. The study indicated that Fittydent is more effective amongst the denture cleansers because of its mechanism of action; however the plant extracts used in this study were also significantly effective against candida albicans. PMID:27042584

  10. Growth and pigment production on D-tryptophan medium by Cryptococcus gattii, Cryptococcus neoformans, and Candida albicans.

    PubMed

    Chaskes, Stuart; Frases, Susana; Cammer, Michael; Gerfen, Gary; Casadevall, Arturo

    2008-01-01

    Given the increasing prevalence of cryptococcosis caused by Cryptococcus gattii (serotypes B and C) strains, there is a need for rapid and reliable tests that discriminate C. gattii from Cryptococcus neoformans (serotypes A, D, and AD). Seventy-two C. neoformans strains, sixty-seven C. gattii strains, and five Candida albicans strains were analyzed for their ability to grow and produce pigment on minimal D-tryptophan D-proline (m-DTDP) medium, on yeast carbon base D-tryptophan D-proline (YCB-DTDP) medium, and on fructose D-tryptophan glycine (m-FDTG) medium. Of the C. gattii and C. neoformans isolates, 94% and 0% grew on m-DTDP agar, respectively, and 98% and 0% grew in YCB-DTDP medium, respectively. C. gattii produced large amounts of brown intracellular pigment(s) on m-DTDP agar and smaller amounts of yellow-brown (amber) extracellular pigment(s). C. albicans grew on both media and produced a pink photoactivated pigment on m-DTDP agar. C. gattii produced large amounts of brown intracellular pigments on the differential medium m-FDTG, whereas C. neoformans produced smaller amounts of the brown pigments and C. albicans produced a pink pigment. The pigments produced by C. gattii from D-tryptophan were distinct and were not related to melanin formation from 3,4-dihydroxyphenylalanine. Thin-layer chromatography of the methanol-extracted C. gattii cells detected four different pigments, including brown (two types), yellow, and pink-purple compounds. We conclude that tryptophan-derived pigments are not melanins and that growth on m-DTDP or YCB-DTDP agar can be used to rapidly differentiate C. gattii from C. neoformans.

  11. Growth and pigment production on D-tryptophan medium by Cryptococcus gattii, Cryptococcus neoformans, and Candida albicans.

    PubMed

    Chaskes, Stuart; Frases, Susana; Cammer, Michael; Gerfen, Gary; Casadevall, Arturo

    2008-01-01

    Given the increasing prevalence of cryptococcosis caused by Cryptococcus gattii (serotypes B and C) strains, there is a need for rapid and reliable tests that discriminate C. gattii from Cryptococcus neoformans (serotypes A, D, and AD). Seventy-two C. neoformans strains, sixty-seven C. gattii strains, and five Candida albicans strains were analyzed for their ability to grow and produce pigment on minimal D-tryptophan D-proline (m-DTDP) medium, on yeast carbon base D-tryptophan D-proline (YCB-DTDP) medium, and on fructose D-tryptophan glycine (m-FDTG) medium. Of the C. gattii and C. neoformans isolates, 94% and 0% grew on m-DTDP agar, respectively, and 98% and 0% grew in YCB-DTDP medium, respectively. C. gattii produced large amounts of brown intracellular pigment(s) on m-DTDP agar and smaller amounts of yellow-brown (amber) extracellular pigment(s). C. albicans grew on both media and produced a pink photoactivated pigment on m-DTDP agar. C. gattii produced large amounts of brown intracellular pigments on the differential medium m-FDTG, whereas C. neoformans produced smaller amounts of the brown pigments and C. albicans produced a pink pigment. The pigments produced by C. gattii from D-tryptophan were distinct and were not related to melanin formation from 3,4-dihydroxyphenylalanine. Thin-layer chromatography of the methanol-extracted C. gattii cells detected four different pigments, including brown (two types), yellow, and pink-purple compounds. We conclude that tryptophan-derived pigments are not melanins and that growth on m-DTDP or YCB-DTDP agar can be used to rapidly differentiate C. gattii from C. neoformans. PMID:17989195

  12. 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.

  13. [Effects of combined addition of atovaquone and lithium on the in vitro cell growth of the pathogenic yeast Candida albicans].

    PubMed

    Minagawa, Nobuko; Uehara, Mariko; Seki, Shiori; Nitta, Ayumi; Kogawara, Kento

    2010-02-01

    Atovaquone, an analog of ubiquinone, binds tightly to the ubiquinol oxidation site (Qo site) of parasite cytochrome bc(1) complex to inhibit electron transport at concentrations far lower than those at which the mammalian system is affected. The mode of action is thought similar to that of myxothiazol. To treat Pneumocystis jirovecii and Plasmodium falciparum infections, atovaquone has been used worldwide whereas it is unapproved in Japan. Since the pathogenic Candida species fungi seem resistant to atovaquone, this drug is not clinically available for candidosis, particularly deep mycosis. We examined the effects of atovaquone on cellular respiration and in vitro growth of C. albicans to explore a new therapeutic possibility for fungal infections. Atovaquone strongly inhibited glucose-dependent cellular respiration similarly to antimycin A, stigmatellin, and myxothiazol, specific bc(1) complex inhibitors. However, atovaquone suppressed glucose-dependent cell growth to a much lesser extent versus the comparator agents. When added alone, lithium exerted slight growth inhibition. The combined addition of lithium with atovaquone showed a significant increase in inhibition of growth. Although the way lithium acts synergistically with atovaquone remains to be elucidated, our results suggest a new therapeutic possibility of this combination for the treatment of candidosis.

  14. 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. PMID:22267663

  15. 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

  16. 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.

  17. 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

  18. Distinct and Redundant Roles of the Two MYST Histone Acetyltransferases Esa1 and Sas2 in Cell Growth and Morphogenesis of Candida albicans

    PubMed Central

    Wang, Xiongjun; Chang, Peng; Ding, Jianping

    2013-01-01

    Candida albicans is associated with humans, as both a harmless commensal organism and a pathogen. Adaption to human body temperature is extremely important for its growth and morphogenesis. Saccharomyces cerevisiae Esa1, a member of the MYST family HATs (histone acetyltransferases) and the catalytic subunit of the NuA4 complex, and its homologues in other eukaryotes have been shown to be essential for cell growth. To investigate the functional roles of two MYST family HATs, Esa1 and Sas2 in C. albicans, we deleted ESA1 and SAS2 in the C. albicans genome and performed cell growth analyses. Our results demonstrated that C. albicans Esa1 is not essential for general growth but is essential for filamentous growth. The esa1/esa1 mutant cells exhibited sensitivity to thermal, genotoxic, and oxidative stresses but tolerance to cold, osmotic, and cell wall stresses. In contrast, the sas2/sas2 mutant adapted to growth at higher temperatures and promoted filament formation at lower temperatures, resembling the phenotype of a C. albicans strain overexpressing ESA1. Cells with deletions of both ESA1 and SAS2 were inviable, reflecting the functional redundancy in cell growth. C. albicans Esa1 and Sas2 have distinct and synergistic effects on histone acetylation at H4K5, H4K12, and H4K16. Esa1 contributes mainly to acetylation of H4K5 and H4K12, whereas Sas2 contributes to acetylation of H4K16. Our findings suggest that C. albicans Esa1 and Sas2 play opposite roles in cell growth and morphogenesis and contribute coordinately to histone acetylation and gene regulation. PMID:23355007

  19. Antibiofilm activity of carboxymethyl chitosan on the biofilms of non-Candida albicans Candida species.

    PubMed

    Tan, Yulong; Leonhard, Matthias; Moser, Doris; Schneider-Stickler, Berit

    2016-09-20

    Although most cases of candidiasis have been attributed to Candida albicans, non-C. albicans Candida species have been isolated in increasing numbers in patients. In this study, we determined the inhibition of carboxymethyl chitosan (CM-chitosan) on single and mixed species biofilm of non-albicans Candida species, including Candida tropicalis, Candida parapsilosis, Candida krusei and Candida glabrata. Biofilm by all tested species in microtiter plates were inhibited nearly 70%. CM-chitosan inhibited mixed species biofilm in microtiter plates and also on medical materials surfaces. To investigate the mechanism, the effect of CM-chitosan on cell viability and biofilm growth was employed. CM-chitosan inhibited Candida planktonic growth as well as adhesion. Further biofilm formation was inhibited with CM-chitosan added at 90min, 12h or 24h after biofilm initiation. CM-chitosan was not only able to inhibit the metabolic activity of Candida cells, but was also active upon the establishment and the development of biofilms. PMID:27261732

  20. Antibiofilm activity of carboxymethyl chitosan on the biofilms of non-Candida albicans Candida species.

    PubMed

    Tan, Yulong; Leonhard, Matthias; Moser, Doris; Schneider-Stickler, Berit

    2016-09-20

    Although most cases of candidiasis have been attributed to Candida albicans, non-C. albicans Candida species have been isolated in increasing numbers in patients. In this study, we determined the inhibition of carboxymethyl chitosan (CM-chitosan) on single and mixed species biofilm of non-albicans Candida species, including Candida tropicalis, Candida parapsilosis, Candida krusei and Candida glabrata. Biofilm by all tested species in microtiter plates were inhibited nearly 70%. CM-chitosan inhibited mixed species biofilm in microtiter plates and also on medical materials surfaces. To investigate the mechanism, the effect of CM-chitosan on cell viability and biofilm growth was employed. CM-chitosan inhibited Candida planktonic growth as well as adhesion. Further biofilm formation was inhibited with CM-chitosan added at 90min, 12h or 24h after biofilm initiation. CM-chitosan was not only able to inhibit the metabolic activity of Candida cells, but was also active upon the establishment and the development of biofilms.

  1. Adaptive immune responses to Candida albicans infection.

    PubMed

    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.

  2. 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.

  3. 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.

  4. Milestones in Candida albicans Gene Manipulation

    PubMed Central

    Samaranayake, Dhanushki P.; Hanes, Steven D.

    2011-01-01

    In the United States, candidemia is one of the most common hospital-acquired infections and is estimated to cause 10,000 deaths per year. The species Candida albicans is responsible for the majority of these cases. As C. albicans is capable of developing resistance against the currently available drugs, understanding the molecular basis of drug resistance, finding new cellular targets, and further understanding the overall mechanism of C. albicans pathogenesis are important goals. To study this pathogen it is advantageous to manipulate its genome. Numerous strategies of C. albicans gene manipulation have been introduced. This review evaluates a majority of these strategies and should be a helpful guide for researchers to identify gene targeting strategies to suit their requirements. PMID:21511047

  5. 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.

  6. Molecular epidemiology of Candida albicans and its closely related yeasts Candida dubliniensis and Candida africana.

    PubMed

    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.

  7. 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

  8. Anticandidal action of fungal chitosan against Candida albicans.

    PubMed

    Tayel, Ahmed A; Moussa, Shaaban; el-Tras, Wael F; Knittel, Dierk; Opwis, Klaus; Schollmeyer, Eckhard

    2010-11-01

    The anticandidal activity of four fungal chitosan types, produced from Mucor rouxii DSM-1191, against three Candida albicans strains was determined. The most bioactive chitosan type, to inhibit C. albicans growth, had the lowest molecular weight (32 kDa) and the highest deacetylation degree (94%). Water soluble types had stronger anticandidal activity than soluble types in 1% acetic acid solution. Scanning electron micrographs of treated C. albicans with fungal chitosan proved that chitosan principally interact with yeast cell wall, causing severe swelling and asymmetric rough shapes, and subsequent cell wall lyses with the prolonging of exposure time. Fungal chitosan could be recommended for C. albicans control as a powerful and safe alternative to synthetic and chemical fungicides. PMID:20603144

  9. [Inhibitory activity of hydrosols prepared from 18 Japanese herbs of weak aromatic flavor against filamentous formation and growth of Candida albicans].

    PubMed

    Inouye, Shigeharu; Takahashi, Miki; Abe, Shigeru

    2012-01-01

    Leaf hydrosols prepared from 18 weakly aromatic Japanese herbs used traditionally were tested on the filamentation-inhibitory activity of Candida albicans. These hydrosols were divided into two classes, A and B. The inhibitory activity of 13 hydrosols belonging to class A was markedly altered depending on the drying process of the parent herbs. On the other hand, the remaining 5 hydrosols belonging to class B showed no significant change on the composition and inhibitory activity upon drying. The change of the bioactivity was correlated with the change and concentration of the respective major constituents. Especially strong bioactivity shown by hydrosols of dried Houttuynia cordata and fresh Prunus pendula was ascribed to n-capric acid and cyanide, respectively. Eight hydrosols exhibited weak or moderate activity against the growth of C. albicans.

  10. [Inhibitory activity of hydrosols prepared from 18 Japanese herbs of weak aromatic flavor against filamentous formation and growth of Candida albicans].

    PubMed

    Inouye, Shigeharu; Takahashi, Miki; Abe, Shigeru

    2012-01-01

    Leaf hydrosols prepared from 18 weakly aromatic Japanese herbs used traditionally were tested on the filamentation-inhibitory activity of Candida albicans. These hydrosols were divided into two classes, A and B. The inhibitory activity of 13 hydrosols belonging to class A was markedly altered depending on the drying process of the parent herbs. On the other hand, the remaining 5 hydrosols belonging to class B showed no significant change on the composition and inhibitory activity upon drying. The change of the bioactivity was correlated with the change and concentration of the respective major constituents. Especially strong bioactivity shown by hydrosols of dried Houttuynia cordata and fresh Prunus pendula was ascribed to n-capric acid and cyanide, respectively. Eight hydrosols exhibited weak or moderate activity against the growth of C. albicans. PMID:22467129

  11. The parasexual lifestyle of Candida albicans.

    PubMed

    Bennett, Richard J

    2015-12-01

    Candida albicans is both a prevalent human commensal and the most commonly encountered human fungal pathogen. This lifestyle is dependent on the ability of the fungus to undergo rapid genetic and epigenetic changes, often in response to specific environmental cues. A parasexual cycle in C. albicans has been defined that includes several unique properties when compared to the related model yeast, Saccharomyces cerevisiae. Novel features include strict regulation of mating via a phenotypic switch, enhanced conjugation within a sexual biofilm, and a program of concerted chromosome loss in place of a conventional meiosis. It is expected that several of these adaptations co-evolved with the ability of C. albicans to colonize the mammalian host.

  12. A Candida albicans PeptideAtlas

    PubMed Central

    Vialas, Vital; Sun, Zhi; Penha, Carla Verónica Loureiro y; Carrascal, Montserrat; Abian, Joaquin; Monteoliva, Lucía; Deutsch, Eric W.; Aebersold, Ruedi; Moritz, Robert L.; Gil, Concha

    2013-01-01

    Candida albicans public proteomic data sets, though growing steadily in the last few years, still have a very limited presence in online repositories. We report here the creation of a C. albicans PeptideAtlas comprising near 22000 distinct peptides at a 0.24 % False Discovery Rate (FDR) that account for over 2500 canonical proteins at a 1.2% FDR. Based on data from 16 experiments, we attained coverage of 41% of the C.albicans open reading frame sequences (ORFs) in the database used for the searches. This PeptideAtlas provides several useful features, including comprehensive protein and peptide-centered search capabilities and visualization tools that establish a solid basis for the study of basic biological mechanisms key to virulence and pathogenesis such as dimorphism, adherence, and apoptosis. Further, it is a valuable resource for the selection of candidate proteotypic peptides for targeted proteomic experiments via selected reaction monitoring (SRM) or SWATH-MS. PMID:23811049

  13. Candida albicans adhesion to composite resin materials.

    PubMed

    Bürgers, Ralf; Schneider-Brachert, Wulf; Rosentritt, Martin; Handel, Gerhard; Hahnel, Sebastian

    2009-09-01

    The adhesion of Candida albicans to dental restorative materials in the human oral cavity may promote the occurrence of oral candidosis. This study aimed to compare the susceptibility of 14 commonly used composite resin materials (two compomers, one ormocer, one novel silorane, and ten conventional hybrid composites) to adhere Candida albicans. Differences in the amount of adhering fungi should be related to surface roughness, hydrophobicity, and the type of matrix. Cylindrical specimens of each material were made according to the manufacturers' instructions. Surface roughness R (a) was assessed by perthometer measurements and the degree of hydrophobicity by computerized contact angle analysis. Specimens were incubated with a reference strain of C. albicans (DMSZ 1386), and adhering fungi were quantified by using a bioluminometric assay in combination with an automated plate reader. Statistical differences were analyzed by the Kruskal-Wallis test and Mann-Whitney U test. Spearman's rank correlation coefficients were calculated to assess correlations. Median R (a) of the tested composite resin materials ranged between 0.04 and 0.23 microm, median contact angles between 69.2 degrees and 86.9 degrees . The two compomers and the ormocer showed lower luminescence intensities indicating less adhesion of fungi than all tested conventional hybrid composites. No conclusive correlation was found between surface roughness, hydrophobicity, and the amount of adhering C. albicans.

  14. Adherence ability of Candida africana: a comparative study with Candida albicans and Candida dubliniensis.

    PubMed

    Romeo, Orazio; De Leo, Filomena; Criseo, Giuseppe

    2011-07-01

    In this study, we compared the adherence ability to human Hela cells and biofilm formation of three closely related Candida yeast. In our experiments, Candida africana showed poor adhesion ability to human Hela cells and the absence of biofilm formation on polyvinyl chloride strips. Conversely, Candida albicans and Candida dubliniensis formed mature biofilms and stable attachment to Hela cells. To our knowledge, this is the first comparative study reporting data on biofilm formation and adherence to human Hela cells by C. africana.

  15. In vitro activity of eugenol against Candida albicans biofilms.

    PubMed

    He, Miao; Du, Minquan; Fan, Mingwen; Bian, Zhuan

    2007-03-01

    Most manifestations of candidiasis are associated with biofilm formation occurring on the surfaces of host tissues and medical devices. Candida albicans is the most frequently isolated causative pathogen of candidiasis, and the biofilms display significantly increased levels of resistance to the conventional antifungal agents. Eugenol, the major phenolic component of clove essential oil, possesses potent antifungal activity. The aim of this study was to investigate the effects of eugenol on preformed biofilms, adherent cells, subsequent biofilm formation and cell morphogenesis of C. albicans. Eugenol displayed in vitro activity against C. albicans cells within biofilms, when MIC(50) for sessile cells was 500 mg/L. C. albicans adherent cell populations (after 0, 1, 2 and 4 h of adherence) were treated with various concentrations of eugenol (0, 20, 200 and 2,000 mg/L). The extent of subsequent biofilm formation were then assessed with the tetrazolium salt reduction assay. Effect of eugenol on morphogenesis of C. albicans cells was observed by scanning electron microscopy (SEM). The results indicated that the effect of eugenol on adherent cells and subsequent biofilm formation was dependent on the initial adherence time and the concentration of this compound, and that eugenol can inhibit filamentous growth of C. albicans cells. In addition, using human erythrocytes, eugenol showed low hemolytic activity. These results indicated that eugenol displayed potent activity against C. albicans biofilms in vitro with low cytotoxicity and therefore has potential therapeutic implication for biofilm-associated candidal infections. PMID:17356790

  16. Effect of tunicamycin on Candida albicans biofilm formation and maintenance

    PubMed Central

    Pierce, Christopher G.; Thomas, Derek P.; López-Ribot, José L.

    2009-01-01

    Background Candida albicans is a common opportunistic pathogen of the human body and is the frequent causative agent of candidiasis. Typically, these infections are associated with the formation of biofilms on both host tissues and implanted biomaterials. As a result of the intrinsic resistance of C. albicans biofilms to most antifungal agents, new strategies are needed to combat these infections. Methods Here we have used a 96-well microtitre plate model of C. albicans biofilm formation to study the inhibitory effect of tunicamycin, a nucleoside antibiotic that inhibits N-linked glycosylation affecting cell wall and secreted proteins, on C. albicans biofilm formation. A proteomic approach was used to study the effect of tunicamycin on levels of glycosylation of key secreted mannoproteins in the biofilm matrix. Results Our results revealed that physiological concentrations of tunicamycin displayed significant inhibitory effects on biofilm development and maintenance, while not affecting overall cell growth or morphology. However, tunicamycin exerted a minimal effect on fully mature, pre-formed C. albicans biofilms. Conclusions The effect of tunicamycin on the C. albicans biofilm mode of growth demonstrates the importance of N-linked glycosylation in the developmental stages of biofilm formation. In addition, our results indicate that N-linked glycosylation represents an attractive target for the development of alternative strategies for the prevention of biofilm formation by this important pathogenic fungus. PMID:19098294

  17. 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.

  18. Coaggregation of Candida albicans, Actinomyces naeslundii and Streptococcus mutans is Candida albicans strain dependent.

    PubMed

    Arzmi, Mohd Hafiz; Dashper, Stuart; Catmull, Deanne; Cirillo, Nicola; Reynolds, Eric C; McCullough, Michael

    2015-08-01

    Microbial interactions are necessarily associated with the development of polymicrobial oral biofilms. The objective of this study was to determine the coaggregation of eight strains of Candida albicans with Actinomyces naeslundii and Streptococcus mutans. In autoaggregation assays, C. albicans strains were grown in RPMI-1640 and artificial saliva medium (ASM) whereas bacteria were grown in heart infusion broth. C. albicans, A. naeslundii and S. mutans were suspended to give 10(6), 10(7) and 10(8) cells mL(-1) respectively, in coaggregation buffer followed by a 1 h incubation. The absorbance difference at 620 nm (ΔAbs) between 0 h and 1 h was recorded. To study coaggregation, the same protocol was used, except combinations of microorganisms were incubated together. The mean ΔAbs% of autoaggregation of the majority of RPMI-1640-grown C. albicans was higher than in ASM grown. Coaggregation of C. albicans with A. naeslundii and/or S. mutans was variable among C. albicans strains. Scanning electron microscopy images showed that A. naeslundii and S. mutans coaggregated with C. albicans in dual- and triculture. In conclusion, the coaggregation of C. albicans, A. naeslundii and S. mutans is C. albicans strain dependent.

  19. Phenotypic consequences of LYS4 gene disruption in Candida albicans.

    PubMed

    Gabriel, Iwona; Kur, Krzysztof; Laforce-Nesbitt, Sonia S; Pulickal, Anoop S; Bliss, Joseph M; Milewski, Sławomir

    2014-08-01

    A BLAST search of the Candida Genome Database with the Saccharomyces cerevisiae LYS4 sequence known to encode homoaconitase (HA) revealed ORFs 19.3846 and 19.11327. Both alleles of the LYS4 gene were sequentially disrupted in Candida albicans BWP17 cells using PCR-based methodology. The null lys4Δ mutant exhibited lysine auxotrophy in minimal medium but was able to grow in the presence of l-Lys and α-aminoadipate, an intermediate of the α-aminoadipate pathway, at millimolar concentrations. The presence of d-Lys and pipecolic acid did not trigger lys4Δ growth. The C. albicans lys4Δ mutant cells demonstrated diminished germination ability. However, their virulence in vivo in a murine model of disseminated neonatal candidiasis appeared identical to that of the wild-type strain. Moreover, there was no statistically significant difference in fungal burden of infected tissues between the strains.

  20. 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. PMID:2500596

  1. Germination of Candida albicans induced by proline.

    PubMed Central

    Dabrowa, N; Taxer, S S; Howard, D H

    1976-01-01

    Blastospores of Candida albicans germinated in proline-biotin-buffer medium incubated at 37 C. Certain other amino acids in the glatamate, asparate, and pyruvate families also fostered germinaton but generally to a lesser extent than did proline. L-Cysteine, D-proline, and certain structural analogues of L-proline inhibited proline-stimualted germination. The concentration of phosphate and glucose was crucial to amino acid-stimulated germination of C. albicans. Clinical isolates and stock cultures varied in their response to the germ tube-inducing activity of proline or other amino acids. The proline-buffer medium cannot be used in a diagnostic test for production of germ tubes by isolates of yeasts. PMID:5375

  2. Inhibition of Candida albicans by Lactobacillus acidophilus.

    PubMed

    Collins, E B; Hardt, P

    1980-05-01

    Candida albicans grew at pH 4.6 or above in nutrient broth containing 5% glucose but was retarded at pH 7.7 by filtrates of Lactobacillus acidophilus grown in casitone broth. Vaginal implantation of nonfermented acidophilus milk, yogurt, or low-fat milk for preventing recurrence of monilia vaginitis subsequent to treatment with Nystatin was studied with 30 women. Reinfections within 3 mo according to product received were: no milk product, 3; yogurt, 1; nonfermented acidophilus milk, 1; and low-fat milk, 0. PMID:6771309

  3. 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.

  4. Analysis of the Candida albicans Phosphoproteome

    PubMed Central

    Willger, S. D.; Liu, Z.; Olarte, R. A.; Adamo, M. E.; Myers, L. C.; Kettenbach, A. N.

    2015-01-01

    Candida albicans is an important human fungal pathogen in both immunocompetent and immunocompromised individuals. C. albicans regulation has been studied in many contexts, including morphological transitions, mating competence, biofilm formation, stress resistance, and cell wall synthesis. Analysis of kinase- and phosphatase-deficient mutants has made it clear that protein phosphorylation plays an important role in the regulation of these pathways. In this study, to further our understanding of phosphorylation in C. albicans regulation, we performed a deep analysis of the phosphoproteome in C. albicans. We identified 19,590 unique peptides that corresponded to 15,906 unique phosphosites on 2,896 proteins. The ratios of serine, threonine, and tyrosine phosphosites were 80.01%, 18.11%, and 1.81%, respectively. The majority of proteins (2,111) contained at least two detected phosphorylation sites. Consistent with findings in other fungi, cytoskeletal proteins were among the most highly phosphorylated proteins, and there were differences in Gene Ontology (GO) terms for proteins with serine and threonine versus tyrosine phosphorylation sites. This large-scale analysis identified phosphosites in protein components of Mediator, an important transcriptional coregulatory protein complex. A targeted analysis of the phosphosites in Mediator complex proteins confirmed the large-scale studies, and further in vitro assays identified a subset of these phosphorylations that were catalyzed by Cdk8 (Ssn3), a kinase within the Mediator complex. These data represent the deepest single analysis of a fungal phosphoproteome and lay the groundwork for future analyses of the C. albicans phosphoproteome and specific phosphoproteins. PMID:25750214

  5. 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. PMID:24252340

  6. The genetic basis of fluconazole resistance development in Candida albicans.

    PubMed

    Morschhäuser, Joachim

    2002-07-18

    Infections by the opportunistic fungal pathogen Candida albicans are widely treated with the antifungal agent fluconazole that inhibits the biosynthesis of ergosterol, the major sterol in the fungal plasma membrane. The emergence of fluconazole-resistant C. albicans strains is a significant problem after long-term treatment of recurrent oropharyngeal candidiasis (OPC) in acquired immunodeficiency syndrome (AIDS) patients. Resistance can be caused by alterations in sterol biosynthesis, by mutations in the drug target enzyme, sterol 14alpha-demethylase (14DM), which lower its affinity for fluconazole, by increased expression of the ERG11 gene encoding 14DM, or by overexpression of genes coding for membrane transport proteins of the ABC transporter (CDR1/CDR2) or the major facilitator (MDR1) superfamilies. Different mechanisms are frequently combined to result in a stepwise development of fluconazole resistance over time. The MDR1 gene is not or barely transcribed during growth in vitro in fluconazole-susceptible C. albicans strains, but overexpressed in many fluconazole-resistant clinical isolates, resulting in reduced intracellular fluconazole accumulation. The activation of the gene in resistant isolates is caused by mutations in as yet unknown trans-regulatory factors, and the resulting constitutive high level of MDR1 expression causes resistance to other toxic compounds in addition to fluconazole. Disruption of both alleles of the MDR1 gene in resistant C. albicans isolates abolishes their resistance to these drugs, providing genetic evidence that MDR1 mediates multidrug resistance in C. albicans. PMID:12084466

  7. Karyotyping of Candida albicans and Candida glabrata from patients with Candida sepsis.

    PubMed

    Klempp-Selb, B; Rimek, D; Kappe, R

    2000-01-01

    The aim of this study was to determine the relatedness of Candida strains from patients suffering from Candida septicaemia by typing of Candida isolates from blood cultures and different body sites by pulsed field gel electrophoresis (PFGE using a contour-clamped homogenous electric field, CHEF). We studied 17 isolates of Candida albicans and 10 isolates of Candida glabrata from six patients. Four patients suffered from a C. albicans septicaemia, one patient from a C. glabrata septicaemia, and one patient had a mixed septicaemia with C. albicans and C. glabrata. Eight isolates from blood cultures were compared with 19 isolates of other sites (stool six, urine four, genital swab four, tip of central venous catheter three, tracheal secretion one, sputum one). PFGE typing resulted in 10 different patterns, four with C. albicans and six with C. glabrata. Five of the six patients had strains of identical PFGE patterns in the blood and at other sites. Seven isolates of a 58-year-old female with a C. glabrata septicaemia fell into five different PFGE patterns. However, they showed minor differences only, which may be due to chromosomal rearrangements within a single strain. Thus it appears, that the colonizing Candida strains were identical to the circulating strains in the bloodstream in at least five of six patients.

  8. Candida albicans Transcriptional Profiling Within Biliary Fluid From a Patient With Cholangitis, Before and After Antifungal Treatment and Surgical Drainage

    PubMed Central

    Clancy, Cornelius J.; Meslin, Camille; Badrane, Hassan; Cheng, Shaoji; Losada, Liliana C.; Nierman, William C.; Vergidis, Pascalis; Clark, Nathan L.; Nguyen, M. Hong

    2016-01-01

    We used ribonucleic acid sequencing to profile Candida albicans transcription within biliary fluid from a patient with cholangitis; samples were collected before and after treatment with fluconazole and drainage. Candida albicans transcriptomes at the infection site distinguished treated from untreated cholangitis. After treatment, 1131 C. albicans genes were differentially expressed in biliary fluid. Up-regulated genes were enriched in hyphal growth, cell wall organization, adhesion, oxidation reduction, biofilm, and fatty acid and ergosterol biosynthesis. This is the first study to define Candida global gene expression during deep-seated human infection. Successful treatment of cholangitis induced C. albicans genes involved in fluconazole responses and pathogenesis.

  9. Molecular cloning and characterization of chitinase genes from Candida albicans.

    PubMed Central

    McCreath, K J; Specht, C A; Robbins, P W

    1995-01-01

    Chitinase (EC 3.2.1.14) is an important enzyme for the remodeling of chitin in the cell wall of fungi. We have cloned three chitinase genes (CHT1, CHT2, and CHT3) from the dimorphic human pathogen Candida albicans. CHT2 and CHT3 have been sequenced in full and their primary structures have been analyzed: CHT2 encodes a protein of 583 aa with a predicted size of 60.8 kDa; CHT3 encodes a protein of 567 aa with a predicted size of 60 kDa. All three genes show striking similarity to other chitinase genes in the literature, especially in the proposed catalytic domain. Transcription of CHT2 and CHT3 was greater when C. albicans was grown in a yeast phase as compared to a mycelial phase. A transcript of CHT1 could not be detected in either growth condition. Images Fig. 2 Fig. 5 PMID:7708682

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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.

  15. Antifungal activities of origanum oil against Candida albicans.

    PubMed

    Manohar, V; Ingram, C; Gray, J; Talpur, N A; Echard, B W; Bagchi, D; Preuss, H G

    2001-12-01

    The antimicrobial properties of volatile aromatic oils from medicinal as well as other edible plants has been recognized since antiquity. Origanum oil, which is used as a food flavoring agent, possesses a broad spectrum of in vitro antimicrobial activities attributed to the high content of phenolic derivatives such as carvacrol and thymol. In the present study, antifungal properties of origanum oil were examined both in vitro and in vivo. Using Candida albicans in broth cultures and a micro dilution method, comparative efficacy of origanum oil, carvacrol, nystatin and amphotericin B were examined in vitro. Origanum oil at 0.25 mg/ml was found to completely inhibit the growth of C. albicans in culture. Growth inhibitions of 75% and >50% were observed at 0.125 mg/ml and 0.0625 mg/ml level, respectively. In addition, both the germination and the mycelial growth of C. albicans were found to be inhibited by origanum oil and carvacrol in a dose-dependent manner. Furthermore, the therapeutic efficacy of origanum oil was examined in an experimental murine systemic candidiasis model. Groups of mice (n = 6) infected with C. albicans (5 x LD50) were fed varying amounts of origanum oil in a final vol. of 0.1 ml of olive oil (vehicle). The daily administration of 8.6 mg of origanum oil in 100 microl of olive oil/kg body weight for 30 days resulted in 80% survivability, with no renal burden of C. albicans as opposed to the group of mice fed olive oil alone, who died within 10 days. Similar results were obtained with carvacrol. However, mice fed origanum oil exhibited cosmetically better clinical appearance compared to those cured with carvacrol. The results from our study encourage examination of the efficacy of origanum oil in other forms of systemic and superficial fungal infections and exploration of its broad spectrum effect against other pathogenic manifestations including malignancy. PMID:11855736

  16. 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.

  17. 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

  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. PMID:27492134

  19. 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.

  20. Morphological and physiological changes induced by contact-dependent interaction between Candida albicans and Fusobacterium nucleatum.

    PubMed

    Bor, Batbileg; Cen, Lujia; Agnello, Melissa; Shi, Wenyuan; He, Xuesong

    2016-01-01

    Candida albicans and Fusobacterium nucleatum are well-studied oral commensal microbes with pathogenic potential that are involved in various oral polymicrobial infectious diseases. Recently, we demonstrated that F. nucleatum ATCC 23726 coaggregates with C. albicans SN152, a process mainly mediated by fusobacterial membrane protein RadD and Candida cell wall protein Flo9. The aim of this study was to investigate the potential biological impact of this inter-kingdom interaction. We found that F. nucleatum ATCC 23726 inhibits growth and hyphal morphogenesis of C. albicans SN152 in a contact-dependent manner. Further analysis revealed that the inhibition of Candida hyphal morphogenesis is mediated via RadD and Flo9 protein pair. Using a murine macrophage cell line, we showed that the F. nucleatum-induced inhibition of Candida hyphal morphogenesis promotes C. albicans survival and negatively impacts the macrophage-killing capability of C. albicans. Furthermore, the yeast form of C. albicans repressed F. nucleatum-induced MCP-1 and TNFα production in macrophages. Our study suggests that the interaction between C. albicans and F. nucleatum leads to a mutual attenuation of virulence, which may function to promote a long-term commensal lifestyle within the oral cavity. This finding has significant implications for our understanding of inter-kingdom interaction and may impact clinical treatment strategies. PMID:27295972

  1. Morphological and physiological changes induced by contact-dependent interaction between Candida albicans and Fusobacterium nucleatum

    PubMed Central

    Bor, Batbileg; Cen, Lujia; Agnello, Melissa; Shi, Wenyuan; He, Xuesong

    2016-01-01

    Candida albicans and Fusobacterium nucleatum are well-studied oral commensal microbes with pathogenic potential that are involved in various oral polymicrobial infectious diseases. Recently, we demonstrated that F. nucleatum ATCC 23726 coaggregates with C. albicans SN152, a process mainly mediated by fusobacterial membrane protein RadD and Candida cell wall protein Flo9. The aim of this study was to investigate the potential biological impact of this inter-kingdom interaction. We found that F. nucleatum ATCC 23726 inhibits growth and hyphal morphogenesis of C. albicans SN152 in a contact-dependent manner. Further analysis revealed that the inhibition of Candida hyphal morphogenesis is mediated via RadD and Flo9 protein pair. Using a murine macrophage cell line, we showed that the F. nucleatum-induced inhibition of Candida hyphal morphogenesis promotes C. albicans survival and negatively impacts the macrophage-killing capability of C. albicans. Furthermore, the yeast form of C. albicans repressed F. nucleatum-induced MCP-1 and TNFα production in macrophages. Our study suggests that the interaction between C. albicans and F. nucleatum leads to a mutual attenuation of virulence, which may function to promote a long-term commensal lifestyle within the oral cavity. This finding has significant implications for our understanding of inter-kingdom interaction and may impact clinical treatment strategies. PMID:27295972

  2. Correlation of atherogenesis with an infection of Candida albicans

    PubMed Central

    Nurgeldiyeva, Maya J; Hojakuliyev, Bayram G; Muhammedov, Merdan B

    2014-01-01

    Purpose: To study contents of atherosclerotic plaques for the presence of fungi of the genus Candida; and an analysis of some immunological and biochemical indices in patients with acute coronary syndrome (ACS) that are positive for Candida albicans. Materials and methods: To test for the presence of fungi in an atherosclerotic plaque, we used a method developed by us (patent NO 531, a priority from 6/28/2010). A total of 47 atherosclerotic plaques were obtained during 20 autopsies. In addition, 80 individuals (58 male, 22 female; age range from 29 to 85) with acute coronary syndrome were subjected to a blood biochemical test, including quantification of TNF-α levels and IgG and IgM to Candida albicans was determined. Results: Fungi of the genus Candida were identified in 31.9% (15 out of 47) of atherosclerotic plaques. Particularly, Candida krusii and Candida grabrata were identified in overwhelming majority, although solitary colonies of Candida tropicalis and a single colony of Candida albicans were also detected. 80 (100%) patients were negative for IgM, but 30 (37.5%) were positive for IgG to Candida albicans. TNF-α was detected in a smaller quantity of IgG-negative patients (36.7%) relative to patients of IgG-positive group (70%), however its levels were considerably above in the first group (511.73±195.80 pg/ml) than in the second one (326.68±259.91 pg/ml, P < 0.05). Differences in the levels of ASAT and ALAT in patients positive to Candida albicans and negative for TNF-α were significantly higher than in the rest of patients. Conclusion: It is conceivable that fungi of the genus Candida are capable of inducing an inflammation of the vascular wall that in turn can lead to the development of atherosclerosis. PMID:25232398

  3. 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.

  4. 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. PMID:23602464

  5. Utilising polyphenols for the clinical management of Candida albicans biofilms.

    PubMed

    Shahzad, Muhammad; Sherry, Leighann; Rajendran, Ranjith; Edwards, Christine A; Combet, Emilie; Ramage, Gordon

    2014-09-01

    Polyphenols (PPs) are secondary metabolites abundant in plant-derived foods. They are reported to exhibit antimicrobial activity that may offer an alternative to existing antimicrobials. The aim of this study was to evaluate the antifungal potential of PPs against Candida albicans biofilms that are commonly recalcitrant to antifungal therapy. The antifungal activity of 14 PPs was assessed in terms of planktonic and sessile minimum inhibitory concentrations (PMICs and SMICs, respectively) against various C. albicans clinical isolates. The most active PPs were further tested for their effect on C. albicans adhesion and biofilm growth using standard biomass assays, microscopy and quantitative gene expression. Of the 14 PPs tested, 7 were effective inhibitors of planktonic growth, of which pyrogallol (PYG) was the most effective (PMIC₅₀=78 μg/mL), followed by curcumin (CUR) (PMIC₅₀=100 μg/mL) and pyrocatechol (PMIC₅₀=625 μg/mL). Both PYG and CUR displayed activity against C. albicans biofilms (SMIC₅₀=40 μg/mL and 50 μg/mL, respectively), although they did not disrupt the biofilm or directly affect the cellular structure. Overall, CUR displayed superior biofilm activity, significantly inhibiting initial cell adhesion following pre-coating (P<0.01), biofilm growth (P<0.05) and gene expression (P<0.05). This inhibitory effect diminished with prolonged CUR exposure, although it still inhibited by 50% after 4h adhesion. Overall, CUR exhibited positive antibiofilm properties that could be used at the basis for development of similar molecules, although further cellular and in vivo studies are required to explore its precise mechanism of action. PMID:25104135

  6. 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

  7. 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.

  8. 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. PMID:26223507

  9. 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.

  10. 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. PMID:26781374

  11. Effects of simulated microgravity by RCCS on the biological features of Candida albicans.

    PubMed

    Jiang, Wenjun; Xu, Bingxin; Yi, Yong; Huang, Yuling; Li, Xiao-Ou; Jiang, Fuquan; Zhou, Jinlian; Zhang, Jianzhong; Cui, Yan

    2014-01-01

    During the spaceflight, a wide variety of microorganisms may be carried to the outer space by astronauts and aviation component. The yeast Candida albicans is an important opportunistic pathogen responsible for a variety of cutaneous and systemic human infections in human body, and the yeast cell itself could be affected by various stressful environmental factors including the weightless environment. We evaluated the effects of simulated microgravity on biological features of Candida albicans using the rotary cell culture system (RCCS). The growth curves of Candida albicans cultured in RCCS were recorded by spectrophotometer, the morphogenic switches were observed by optical microscope, and the viability of cells exposed to the various concentrations of fluconazole solution was assayed by flow cytometry at 7th, 14th and 21st day of experiment. The results showed that Candida albicans SC5314 under modeled microgravity were manifested as the growth curves leftward-shifted, lag phase shortened, along with logarithmic phase and stationary phase forwarded (P < 0.05). The simulated microgravity increased the growth rate and mycelia formation of Candida albicans. A statistically significant decrease in viability was detected in cells cultured for 7 d, 14 d and 21 d in group of simulated microgravity compared with the control group (P < 0.05). The increase of exposure time to simulate microgravity resulted in the decrease of viability of cells accordingly in same drug concentration compared with the control group. The study demonstrated that the three weeks' simulated microgravity in RCCS had a noticeable affect on the growth status of mycelia and spores and the morphogenic switches of Candida albicans, meanwhile, the yeast cells under simulated microgravity showed an increased antifungal susceptibility to fluconazole. PMID:25120754

  12. Synthetic arylquinuclidine derivatives exhibit antifungal activity against Candida albicans, Candida tropicalis and Candida parapsilopsis

    PubMed Central

    2011-01-01

    Background Sterol biosynthesis is an essential pathway for fungal survival, and is the biochemical target of many antifungal agents. The antifungal drugs most widely used to treated fungal infections are compounds that inhibit cytochrome P450-dependent C14α-demethylase (CYP51), but other enzymes of this pathway, such as squalene synthase (SQS) which catalyses the first committed step in sterol biosynthesis, could be viable targets. The aim of this study was to evaluate the antifungal activity of SQS inhibitors on Candida albicans, Candida tropicalis and Candida parapsilopsis strains. Methods Ten arylquinuclidines that act as SQS inhibitors were tested as antiproliferative agents against three ATCC strains and 54 clinical isolates of Candida albicans, Candida tropicalis and Candida parapsilopsis. Also, the morphological alterations induced in the yeasts by the experimental compounds were evaluated by fluorescence and transmission electron microscopy. Results The most potent arylquinuclidine derivative (3-[1'-{4'-(benzyloxy)-phenyl}]-quinuclidine-2-ene) (WSP1267) had a MIC50 of 2 μg/ml for all species tested and MIC90 varying from 4 μg/ml to 8 μg/ml. Ultrathin sections of C. albicans treated with 1 μg/ml of WSP1267 showed several ultrastructural alterations, including (a) loss of cell wall integrity, (b) detachment of the plasma membrane from the fungal cell wall, (c) accumulation of small vesicles in the periplasmic region, (d) presence of large electron-dense vacuoles and (e) significantly increased cell size and cell wall thickness. In addition, fluorescence microscopy of cells labelled with Nile Red showed an accumulation of lipid droplets in the cytoplasm of treated yeasts. Nuclear staining with DAPI revealed the appearance of uncommon yeast buds without a nucleus or with two nuclei. Conclusion Taken together, our data demonstrate that arylquinuclidine derivatives could be useful as lead compounds for the rational synthesis of new antifungal drugs. PMID

  13. 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.

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

    PubMed

    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.

  15. 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

  16. 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. PMID:23107627

  17. 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

  18. In Vitro Activity of Caspofungin against Candida albicans Biofilms

    PubMed Central

    Bachmann, Stefano P.; VandeWalle, Kacy; Ramage, Gordon; Patterson, Thomas F.; Wickes, Brian L.; Graybill, John R.; López-Ribot, José L.

    2002-01-01

    Most manifestations of candidiasis are associated with biofilm formation on biological or inanimate surfaces. Candida albicans biofilms are recalcitrant to treatment with conventional antifungal therapies. Here we report on the activity of caspofungin, a new semisynthetic echinocandin, against C. albicans biofilms. Caspofungin displayed potent in vitro activity against sessile C. albicans cells within biofilms, with MICs at which 50% of the sessile cells were inhibited well within the drug's therapeutic range. Scanning electron microscopy and confocal scanning laser microscopy were used to visualize the effects of caspofungin on preformed C. albicans biofilms, and the results indicated that caspofungin affected the cellular morphology and the metabolic status of cells within the biofilms. The coating of biomaterials with caspofungin had an inhibitory effect on subsequent biofilm development by C. albicans. Together these findings indicate that caspofungin displays potent activity against C. albicans biofilms in vitro and merits further investigation for the treatment of biofilm-associated infections. PMID:12384370

  19. New aniline blue dye medium for rapid identification and isolation of Candida albicans.

    PubMed Central

    Goldschmidt, M C; Fung, D Y; Grant, R; White, J; Brown, T

    1991-01-01

    Organic dyes have long been used in diagnostic microbiology to differentiate species by color reactions. We studied the ability of a new noninhibitory medium, YM agar containing 0.01% aniline blue WS dye, Colour Index 42780 (YMAB), to identify Candida albicans among 1,554 yeast specimens obtained from seven clinical laboratories. Appropriate American Type Culture Collection and other characterized strains served as controls. A total of 487 of the clinical strains were identified as C. albicans. The remainder were other Candida species and non-Candida yeasts. Clinical isolates and controls were grown on Sabouraud agar for 18 h at 30 degrees C and then transferred to YMAB. Plates were incubated for 12 to 18 h at 30 degrees C, and colonies were observed for yellow-green fluorescence under long-wave UV light (A365). All control strains of C. albicans and Candida stellatoidea fluoresced, as did 480 of the 490 isolates designated as C. albicans (which included 3 strains of C. stellatoidea). Cells of C. albicans grown on YMAB produced germ tubes in serum. Only five of the other 1,062 non-C. albicans yeasts fluoresced. The sensitivity and specificity were 98.0 and 99.5%, respectively, with a predictive value of 99.1%. A fluorescent metabolite was found in cell wall particulate fractions of C. albicans sonic extracts grown on YMAB but not in non-C. albicans yeasts. This metabolite showed the same spectral curve as those of metabolites from whole cells in a recording spectrofluorometer when it was excited at 400 nm and scanned from 420 to 550 nm. Thus, growth on YMAB generates the production of a fluorescent moiety that can be used to specifically identify C. albicans within 12 to 18 h. Images PMID:1864924

  20. 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. PMID:26416861

  1. 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

  2. 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.

  3. Binding of the extracellular matrix component entactin to Candida albicans.

    PubMed Central

    López-Ribot, J L; Chaffin, W L

    1994-01-01

    We have investigated the interaction between Candida albicans and entactin, a recently characterized glycoprotein present in the extracellular matrix, especially in the basement membrane. Organisms of both the yeast and the hyphal morphologies of the fungus had the ability to bind recombinant entactin, as detected by an indirect immunofluorescence assay. Material present in the 2-mercaptoethanol cell wall extracts from both C. albicans growth forms was capable of binding to immobilized recombinant entactin in a dose-dependent manner. Binding to entactin was approximately twice that observed for laminin. Binding of an extract component(s) to entactin was partially inhibited by an Arg-Gly-Asp-Ser peptide. A polyclonal antientactin antiserum, as well as a pooled antiserum preparation raised against components present in different C. albicans cell wall extracts, completely or almost completely abolished binding. The existence of morphology-specific receptor-like molecules which bind to different domains of the entactin molecule was ruled out in a competition binding assay. The entactin-binding material(s) in the cell wall also displayed some ability to bind laminin and fibronectin, since preadsorption in the presence of these extracellular matrix components resulted in reduction of binding to entactin. Moieties with a molecular mass of approximately 25, 44, and 65 kDa present in the 2-mercaptoethanol cell wall extracts from both blastoconidia and germ tubes were detected in a ligand affinity blotting experiment as having the ability to bind entactin. Interactions between C. albicans and entactin could be important in mediating adhesion of the fungus to the host tissues and may play a role in the establishment of the disseminated form of the disease. Images PMID:7927722

  4. Characterization of extracellular nucleotide metabolism in Candida albicans.

    PubMed

    Rodrigues, Lisa; Russo-Abrahão, Thais; Cunha, Rodrigo A; Gonçalves, Teresa; Meyer-Fernandes, José Roberto

    2016-01-01

    Candida albicans is the most frequent agent of human disseminated fungal infection. Ectophosphatase and ectonucleotidase activities are known to influence the infectious potential of several microbes, including other non-albicans species of Candida. With the present work we aim to characterize these ecto-enzymatic activities in C. albicans. We found that C. albicans does not have a classical ecto-5'-nucleotidase enzyme and 5'AMP is cleaved by a phosphatase instead of exclusively by a nucleotidase that also can use 3'AMP as a substrate. Moreover, these enzymatic activities are not dependent on secreted soluble enzymes and change when the yeast cells are under infection conditions, including low pH, and higher temperature and CO2 content.

  5. 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

  6. 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

  7. Recurrent Candida albicans Ventriculitis Treated with Intraventricular Liposomal Amphotericin B.

    PubMed

    Toprak, Demet; Öcal Demir, Sevliya; Kadayifci, Eda Kepenekli; Türel, Özden; Soysal, Ahmet; Bakir, Mustafa

    2015-01-01

    Central nervous system (CNS) infection with Candida is rare but significant because of its high morbidity and mortality. When present, it is commonly seen among immunocompromised and hospitalized patients. Herein, we describe a case of a four-year-old boy with acute lymphoblastic leukemia (ALL) who experienced recurrent Candida albicans meningitis. The patient was treated successfully with intravenous liposomal amphotericin B at first attack, but 25 days after discharge he was readmitted to hospital with symptoms of meningitis. Candida albicans was grown in CFS culture again and cranial magnetic resonance imaging (MRI) showed ventriculitis. We administered liposomal amphotericin B both intravenously and intraventricularly and favorable result was achieved without any adverse effects. Intraventricular amphotericin B may be considered for the treatment of recurrent CNS Candida infections in addition to intravenous administration. PMID:26558119

  8. Recurrent Candida albicans Ventriculitis Treated with Intraventricular Liposomal Amphotericin B

    PubMed Central

    Toprak, Demet; Öcal Demir, Sevliya; Kadayifci, Eda Kepenekli; Türel, Özden; Soysal, Ahmet; Bakir, Mustafa

    2015-01-01

    Central nervous system (CNS) infection with Candida is rare but significant because of its high morbidity and mortality. When present, it is commonly seen among immunocompromised and hospitalized patients. Herein, we describe a case of a four-year-old boy with acute lymphoblastic leukemia (ALL) who experienced recurrent Candida albicans meningitis. The patient was treated successfully with intravenous liposomal amphotericin B at first attack, but 25 days after discharge he was readmitted to hospital with symptoms of meningitis. Candida albicans was grown in CFS culture again and cranial magnetic resonance imaging (MRI) showed ventriculitis. We administered liposomal amphotericin B both intravenously and intraventricularly and favorable result was achieved without any adverse effects. Intraventricular amphotericin B may be considered for the treatment of recurrent CNS Candida infections in addition to intravenous administration. PMID:26558119

  9. [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.

  10. Molecular concordance of concurrent Candida albicans candidemia and candiduria.

    PubMed

    Huang, Po-Yen; Hung, Min-Hui; Shie, Shian-Sen; Su, Lin-Hui; Chen, Ke-Yuan; Ye, Jung-Jr; Chiang, Ping-Cheng; Leu, Hsieh-Shong; Huang, Ching-Tai

    2013-07-01

    The significance of candiduria remains unclear. We correlated Candida albicans candidemia with candiduria by molecular genotyping. 33 pairs of concurrent blood and urine C. albicans isolates from 31 adult (≥ 18 years) were genotyped with infrequent-restriction-site PCR. The molecular concordance rates of three major genotypes were 100% for I, 82% for II, and 71% for III. The molecular concordance between concurrent C. albicans candidemia and candiduria was frequent. Our findings substantiate the importance of candiduria in appropriate clinical context as the majority of our patients were from intensive care units.

  11. Relationship between salivary flow rates and Candida albicans counts.

    PubMed

    Navazesh, M; Wood, G J; Brightman, V J

    1995-09-01

    Seventy-one persons (48 women, 23 men; mean age, 51.76 years) were evaluated for salivary flow rates and Candida albicans counts. Each person was seen on three different occasions. Samples of unstimulated whole, chewing-stimulated whole, acid-stimulated parotid, and candy-stimulated parotid saliva were collected under standardized conditions. An oral rinse was also obtained and evaluated for Candida albicans counts. Unstimulated and chewing-stimulated whole flow rates were negatively and significantly (p < 0.001) related to the Candida counts. Unstimulated whole saliva significantly (p < 0.05) differed in persons with Candida counts of 0 versus <500 versus < or = 500. Chewing-stimulated saliva was significantly (p < 0.05) different in persons with 0 counts compared with those with a > or = 500 count. Differences in stimulated parotid flow rates were not significant among different levels of Candida counts. The results of this study reveal that whole saliva is a better predictor than parotid saliva in identification of persons with high Candida albicans counts.

  12. 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

  13. HWY-289, a novel semi-synthetic protoberberine derivative with multiple target sites in Candida albicans.

    PubMed

    Park, K S; Kang, K C; Kim, K Y; Jeong, P Y; Kim, J H; Adams, D J; Kim, J H; Paik, Y K

    2001-05-01

    The antifungal properties of 515 synthetic and semi-synthetic protoberberines were investigated. HWY-289 was chosen for further study because it exhibited the most significant anti-Candida activity (MICs were 1.56 mg/L for Candida albicans and Candida krusei; 6.25 mg/L for Candida guilliermondii) but did not demonstrate toxicity in rats. HWY-289 inhibited the incorporation of L-[methyl-(14)C]methionine into the C-24 of ergosterol in whole cells of C. albicans (IC(50) 20 microM). However, HWY-289 (100 microM) had no effect on mammalian cholesterol biosynthesis in rat microsomes while miconazole (100 microM) was a potent inhibitor of cholesterol biosynthesis under identical assay conditions. A second major target site for HWY-289 was identified that involves cell wall biosynthesis in C. albicans. HWY-289 was a potent inhibitor of the chitin synthase isozymes CaCHS1 and CaCHS2, with IC(50) values of 22 microM for each enzyme. The effect was highly specific in that HWY-289 had no significant effect on C. albicans CaCHS3 (IC(50) > 200 microM). Thus, HWY-289 compared favourably with well-established antifungal agents as an inhibitor of the growth of Candida species in vitro, and may have considerable potential as a new class of antifungal agent that lacks toxic side effects in the human host.

  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. 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

  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. 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

  19. Changes in cell morphology and carnitine acetyltransferase activity in Candida albicans following growth on lipids and serum and after in vivo incubation in mice.

    PubMed

    Sheridan, R; Ratledge, C

    1996-11-01

    Candida albicans C316, maintained in the yeast form, showed a proliferation of peroxisomes when grown on triolein or serum as sole carbon source but these structures were absent from glucose-grown cells. Peroxisomes were also apparent in C. albicans obtained after injection into mice and recovery from intraperitoneal washings and kidneys; they may therefore be useful markers to assess a potential in vivo response in cells that are growing in vitro. Transcell-wall structures also occurred in C. albicans grown on triolein or serum, and in cells cultured in vivo, but were not seen in cells grown on glucose. These structures consisted of electron-dense fibrillar material penetrating through the cell wall from the plasmalemma side and protruded out to the exterior of the cell. Endoplasmic reticulum, located at the periphery of the cell, was found to be in close proximity with these cell wall structures. Carnitine acetyltransferase (CAT; EC 2.3.1.7), the key enzyme for the translocation of acetyl units between intracellular compartments, was present in low activities in glucose-grown cells; its activity was increased some 100-fold in triolein-grown cells but only 4-fold in serum-grown cells. It was not possible to assess this activity in the in vivo-cultured cells. Two separate CAT proteins, partially purifed from isolated microchondria and peroxisomes, respectively, were identified, with different specificities and kinetic properties. PMID:8969514

  20. 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

  1. 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.

  2. 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.

  3. Growth inhibition of Candida by human oral epithelial cells.

    PubMed

    Steele, C; Leigh, J; Swoboda, R; Fidel, P L

    2000-11-01

    Oropharyngeal candidiasis (OPC) caused by Candida albicans is a significant problem in human immunodeficiency virus (HIV)-infected persons. Recognizing the paucity of information on innate and/or adaptive mucosal host defenses against C. albicans, we recently reported that human and nonhuman primate and mouse vaginal epithelial cells inhibit the growth of C. albicans in vitro. In the present study, oral epithelial cells collected from saliva of healthy volunteers and a purified oral epithelial cell line were found to inhibit blastoconidia and/or hyphal growth of several Candida species. Cell contact was a strict requirement for the epithelial cell anti-Candida activity; neither saliva nor culture supernatants alone inhibited Candida growth, and addition of saliva to the coculture did not modulate the epithelial cell activity. Finally, epithelial cell anti-Candida activity was significantly lower in HIV-infected persons with OPC. Together, these results suggest that oral epithelial cells may play a role in innate resistance against OPC.

  4. 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.

  5. 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

  6. Rat indwelling urinary catheter model of Candida albicans biofilm infection.

    PubMed

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

    2014-12-01

    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.

  7. 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

  8. 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.

  9. 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.

  10. Effect of Marine Polyunsaturated Fatty Acids on Biofilm Formation of Candida albicans and Candida dubliniensis

    PubMed Central

    Thibane, Vuyisile S.; Kock, Johan L. F.; Ells, Ruan; van Wyk, Pieter W. J.; Pohl, Carolina H.

    2010-01-01

    The effect of marine polyunsaturated fatty acids on biofilm formation by the human pathogens Candida albicans and Candida dubliniensis was investigated. It was found that stearidonic acid (18:4 n-3), eicosapentaenoic acid (20:5 n-3), docosapentaenoic acid (22:5 n-3) and docosahexaenoic acid (22:6 n-3) have an inhibitory effect on mitochondrial metabolism of both C. albicans and C. dubliniensis and that the production of biofilm biomass by C. dubliniensis was more susceptible to these fatty acids than C. albicans. Ultrastructural differences, which may be due to increased oxidative stress, were observed between treated and untreated cells of C. albicans and C. dubliniensis with formation of rough cell walls by both species and fibrillar structures in C. dubliniensis. These results indicate that marine polyunsaturated fatty acids may be useful in the treatment and/or prevention of biofilms formed by these pathogenic yeasts. PMID:21116408

  11. 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.

  12. 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. PMID:16954270

  13. 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.

  14. 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.

  15. Neutrophil activation by Candida glabrata but not Candida albicans promotes fungal uptake by monocytes.

    PubMed

    Duggan, Seána; Essig, Fabian; Hünniger, Kerstin; Mokhtari, Zeinab; Bauer, Laura; Lehnert, Teresa; Brandes, Susanne; Häder, Antje; Jacobsen, Ilse D; Martin, Ronny; Figge, Marc Thilo; Kurzai, Oliver

    2015-09-01

    Candida albicans and Candida glabrata account for the majority of candidiasis cases worldwide. Although both species are in the same genus, they differ in key virulence attributes. Within this work, live cell imaging was used to examine the dynamics of neutrophil activation after confrontation with either C. albicans or C. glabrata. Analyses revealed higher phagocytosis rates of C. albicans than C. glabrata that resulted in stronger PMN (polymorphonuclear cells) activation by C. albicans. Furthermore, we observed differences in the secretion of chemokines, indicating chemotactic differences in PMN signalling towards recruitment of further immune cells upon confrontation with Candida spp. Supernatants from co-incubations of neutrophils with C. glabrata primarily attracted monocytes and increased the phagocytosis of C. glabrata by monocytes. In contrast, PMN activation by C. albicans resulted in recruitment of more neutrophils. Two complex infection models confirmed distinct targeting of immune cell populations by the two Candida spp.: In a human whole blood infection model, C. glabrata was more effectively taken up by monocytes than C. albicans and histopathological analyses of murine model infections confirmed primarily monocytic infiltrates in C. glabrata kidney infection in contrast to PMN-dominated infiltrates in C. albicans infection. Taken together, our data demonstrate that the human opportunistic fungi C. albicans and C. glabrata are differentially recognized by neutrophils and one outcome of this differential recognition is the preferential uptake of C. glabrata by monocytes.

  16. Enhancement of non-Candida antibody responses by Candida albicans cell wall glycoprotein.

    PubMed

    Domer, J E; Elkins, K L; Ennist, D L; Stashak, P W; Garner, R E; Baker, P J

    1987-11-01

    Two cell wall glycoprotein extracts from Candida albicans (glycoprotein [GP] and peptidoglucomannan [PGM]) were tested for their influence on antibody responses to type III pneumococcal polysaccharide and sheep erythrocytes. GP was isolated from lipid-extracted cell walls with ethylenediamine, whereas PGM was extracted with dilute sodium hydroxide. Both glycoproteins increased the number of antibody-producing plaque-forming cells in the spleens of mice immunized with type III polysaccharide or sheep erythrocytes, although PGM appeared to be about 10 times more effective. PGM could be administered up to 3 days prior to immunization with sheep erythrocytes to elicit enhancement; it did not have to be administered by the same route as the immunogen to cause significant enhancement. Enhancement did not appear to be the result of a direct mitogenic effect of GP and PGM on lymphocytes, nor did these glycoproteins appear to stimulate the production of B-cell growth factors or interleukin 2.

  17. Cilofungin (LY121019), an antifungal agent with specific activity against Candida albicans and Candida tropicalis.

    PubMed Central

    Hall, G S; Myles, C; Pratt, K J; Washington, J A

    1988-01-01

    Cilofungin (LY121019) is an antifungal agent that interferes with beta-glucan synthesis in the cells walls of fungi. The activity of this agent against 256 clinical isolates of yeasts was determined. It was found to be very active in vitro against Candida albicans (MIC for 90% of isolates [MIC90], less than or equal to 0.31 microgram/ml; minimal fungicidal concentration for 90% of isolates [MFC90], less than or equal to 0.31 micrograms/ml) and C. tropicalis (MIC90, less than or equal to 0.31 microgram/ml; MFC90, less than or equal to 0.31 microgram/ml) and moderately active against Torulopsis glabrata (MIC90 and MFC90, less than or equal to 20 micrograms/ml). All C. parapsilosis, Cryptococcus, and Saccharomyces cerevisiae strains were resistant. The activity of cilofungin was affected by medium and inoculum size. Antibiotic medium no. 3 was used as the standard medium. Isolates of C. albicans and C. tropicalis demonstrated a paradoxical effect in Sabouraud dextrose broth and yeast nitrogen base broth in that growth was partially inhibited at MICs equivalent to those in antibiotic medium no. 3, but growth continued, in many instances, throughout all concentrations tested. There was decreased activity of cilofungin with inocula greater than 10(5) CFU/ml. The temperature and duration of incubation did not affect its activity. Images PMID:3058017

  18. 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

  19. Oxidative stress of photodynamic antimicrobial chemotherapy inhibits Candida albicans virulence

    NASA Astrophysics Data System (ADS)

    Kato, Ilka Tiemy; Prates, Renato Araujo; Tegos, George P.; Hamblin, Michael R.; Simões Ribeiro, Martha

    2011-03-01

    Photodynamic antimicrobial chemotherapy (PACT) is based on the principal that microorganisms will be inactivated using a light source combined to a photosensitizing agent in the presence of oxygen. Oxidative damage of cell components occurs by the action of reactive oxygen species leading to cell death for microbial species. It has been demonstrated that PACT is highly efficient in vitro against a wide range of pathogens, however, there is limited information for its in vivo potential. In addition, it has been demonstrated that sublethal photodynamic inactivation may alter the virulence determinants of microorganisms. In this study, we explored the effect of sublethal photodynamic inactivation to the virulence factors of Candida albicans. Methylene Blue (MB) was used as photosensitizer for sublethal photodynamic challenge on C. albicans associated with a diode laser irradiation (λ=660nm). The parameters of irradiation were selected in causing no reduction of viable cells. The potential effects of PACT on virulence determinants of C. albicans cells were investigated by analysis of germ tube formation and in vivo pathogenicity assays. Systemic infection was induced in mice by the injection of fungal suspension in the lateral caudal vein. C. albicans exposed to sublethal photodynamic inactivation formed significantly less germ tube than untreated cells. In addition, mice infected with C. albicans submitted to sublethal PACT survived for a longer period of time than mice infected with untreated cells. The oxidative damage promoted by sublethal photodynamic inactivation inhibited virulence determinants and reduced in vivo pathogenicity of C. albicans.

  20. Dental caries in rats associated with Candida albicans.

    PubMed

    Klinke, T; Guggenheim, B; Klimm, W; Thurnheer, T

    2011-01-01

    In addition to occasional opportunistic colonization of the oral mucosa, Candida albicans is frequently found in carious dentin. The yeast's potential to induce dental caries as a consequence of its pronounced ability to produce and tolerate acids was investigated. Eighty caries-active Osborne-Mendel rats were raised on an ampicillin-supplemented diet and exposed to C. albicans and/or Streptococcus mutans, except for controls. Throughout the 28-day test period, the animals were offered the modified cariogenic diet 2000a, containing 40% various sugars. Subsequently, maxillary molars were scored for plaque extent. After dissection, the mandibular molars were evaluated for smooth surface and fissure caries. Test animals exposed to C. albicans displayed considerably more advanced fissure lesions (p < 0.001) than non-exposed controls. While S. mutans yielded similar results, a combined association of C. albicans and S. mutans had no effect on occlusal caries incidence. Substituting dietary sucrose by glucose did not modify caries induction by C. albicans. However, animals fed a diet containing 20% of both sugars showed no differences to non-infected controls. Smooth surface caries was not generated by the yeast. This study provides experimental evidence that C. albicans is capable of causing occlusal caries in rats at a high rate.

  1. Effect of UV irradiation on lethal infection of mice with Candida albicans.

    PubMed

    Denkins, Y M; Kripke, M L

    1993-02-01

    Exposure of mice to UV radiation inhibits the induction and elicitation of the delayed-type hypersensitivity (DTH) response to Candida albicans. To determine whether UV irradiation also affects the pathogenesis of systemic C. albicans infection, C3H mice were exposed to a single dose of 48 kJ/m2 UV-B radiation from FS40 sunlamps 5 days before or 5 days after sensitization with formalin-fixed C. albicans and challenged intravenously (i.v.) with a lethal dose of viable fungi 6 days after sensitization (11 or 1 days after UV irradiation). Exposing unsensitized mice to UV radiation 11 days before lethal challenge had no effect on survival, but the survival time of mice exposed to UV radiation 1 day before challenge was reduced by more than 50%. In the latter group, decreased survival time correlated with persistence of C. albicans in the brain and progressive growth of C. albicans in the kidneys. Sensitization of unirradiated mice with formalin-fixed C. albicans extended their survival time following lethal i.v. challenge with viable C. albicans. Exposing the mice to UV radiation 5 days before sensitization did not abrogate this beneficial effect of sensitization on survival, even though it significantly reduced the DTH response. Thus, immunity to systemic infection did not depend on the ability of the mice to exhibit a DTH response to C. albicans. The beneficial effect of sensitization on survival after lethal infection was abrogated, however, in mice exposed to UV radiation 1 day before lethal challenge with C. albicans. Furthermore, these mice were unable to contain the progressive growth of C. albicans in the kidneys, in contrast to sensitized, unirradiated mice. PMID:8451288

  2. 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.

  3. 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

  4. Beyond the wall: Candida albicans secret(e)s to survive.

    PubMed

    Sorgo, Alice G; Heilmann, Clemens J; Brul, Stanley; de Koster, Chris G; Klis, Frans M

    2013-01-01

    The opportunistic fungal pathogen Candida albicans occupies various niches of the human body such as the skin and the mucosal surfaces of the gastrointestinal and urogenital tracts. It can also enter the blood stream and cause deadly, systemic infections, especially in immunocompromised patients, but also in immunocompetent individuals through inserted medical devices. To survive in these diverse host environments, C. albicans has developed specialized virulence attributes and rapidly adapts itself to local growth conditions and defense mechanisms. Candida albicans secretes a considerable number of proteins that are involved in biofilm formation, tissue invasion, immune evasion, and wall maintenance, as well as acquisition of nutrients including metal ions. The secretome of C. albicans is predicted to comprise 225 proteins. On a proteomic level, however, analysis of the secretome of C. albicans is incomplete as many secreted proteins are only produced under certain conditions. Interestingly, glycosylphosphatidylinositol proteins and known cytoplasmic proteins are also consistently detected in the growth medium. Importantly, a core set of seven wall polysaccharide-processing enzymes seems to be consistently present, including the diagnostic marker Mp65. Overall, we discuss the importance of the secretome for virulence and suggest potential targets for better and faster diagnostic methods.

  5. 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

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

    PubMed

    Johnson, Chad J; Cabezas-Olcoz, Jonathan; Kernien, John F; Wang, Steven X; Beebe, David J; Huttenlocher, Anna; Ansari, Hamayail; Nett, Jeniel E

    2016-09-01

    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

  7. Beyond the wall: Candida albicans secret(e)s to survive.

    PubMed

    Sorgo, Alice G; Heilmann, Clemens J; Brul, Stanley; de Koster, Chris G; Klis, Frans M

    2013-01-01

    The opportunistic fungal pathogen Candida albicans occupies various niches of the human body such as the skin and the mucosal surfaces of the gastrointestinal and urogenital tracts. It can also enter the blood stream and cause deadly, systemic infections, especially in immunocompromised patients, but also in immunocompetent individuals through inserted medical devices. To survive in these diverse host environments, C. albicans has developed specialized virulence attributes and rapidly adapts itself to local growth conditions and defense mechanisms. Candida albicans secretes a considerable number of proteins that are involved in biofilm formation, tissue invasion, immune evasion, and wall maintenance, as well as acquisition of nutrients including metal ions. The secretome of C. albicans is predicted to comprise 225 proteins. On a proteomic level, however, analysis of the secretome of C. albicans is incomplete as many secreted proteins are only produced under certain conditions. Interestingly, glycosylphosphatidylinositol proteins and known cytoplasmic proteins are also consistently detected in the growth medium. Importantly, a core set of seven wall polysaccharide-processing enzymes seems to be consistently present, including the diagnostic marker Mp65. Overall, we discuss the importance of the secretome for virulence and suggest potential targets for better and faster diagnostic methods. PMID:23170918

  8. [Progress on the role of Toll-like receptors in Candida albicans infections].

    PubMed

    Yun, Zhou; Jianping, Pan

    2016-05-25

    Toll like receptors (TLRs) are expressed mainly on innate immunocytes such as dendritic cells and macrophages, and may have the potential to recognize and bind to pathogen-associated molecular patterns (PAMPs) from Candida albicans, thereby triggering the downstream signals. The genetic polymorphism of TLRs is associated with susceptibility to Candida albicans. The activation of TLRs by PAMPs from Candida albicans can induce the production of proinflammatory cytokines that play key roles in the anti-infection of Candida albicans. However, in order to evade the immune response of host,Candida albicans can also change its bacterial phase. Understanding of the interaction between TLRs and Candida albicans will provide novel evidence to further clarify the mechanisms of anti-fungal immune response. PMID:27651197

  9. Specific induction of fibronectin binding activity by hemoglobin in Candida albicans grown in defined media.

    PubMed

    Yan, S; Nègre, E; Cashel, J A; Guo, N; Lyman, C A; Walsh, T J; Roberts, D D

    1996-08-01

    Fibronectin (FN) is a major component of host extracellular matrix that may play an important role in the initiation and dissemination of Candida albicans infections. Expression of FN binding requires growth of C albicans blastoconidia in complex medium, and the regulation of FN receptor expression is poorly understood. We now demonstrate that hemoglobin is a potent and specific inducer of FN receptor expression and describe a defined medium supplemented with hemoglobin that greatly and stably enhances the binding activity of C. albicans for soluble FN. Enhancement of FN binding by hemoglobin in strain 44807 was concentration dependent and was maximal at 0.1% hemoglobin with 20- to 80-fold enhancement. The hemoglobin-induced FN binding to C. albicans was saturable, with a Kd of 2.7 X 10(-8) M. Enhancement required growth of C. albicans in hemoglobin-containing medium, since simply exposing blastoconidia to hemoglobin in a nongrowing status did not enhance binding. Induction was reversible following removal of hemoglobin from the growth medium and not associated with germination. Inorganic or protein-bound iron was not sufficient for the induction, since other iron-containing proteins or inorganic iron salts were inactive. Growth in the simple medium yeast nitrogen base supplemented with hemoglobin increased cell adhesion to immobilized FN and to cultured monolayers of bovine corneal endothelial cells. These data suggest that hemoglobin may be an important regulator of FN binding activity in C. albicans and thus may play a role in its pathogenesis. PMID:8757815

  10. Biotyping of Candida albicans: results of an international collaborative survey.

    PubMed Central

    Odds, F C; Auger, P; Krogh, P; Neely, A N; Segal, E

    1989-01-01

    An agar plate system for biotyping isolates of Candida albicans was evaluated in four laboratories for 18 coded yeast isolates, each tested in triplicate on duplicate series of agar plates. The results showed that the biotyping system gave excellent intralaboratory reproducibility. However, because the concordance of data among laboratories was poor, the method must be regarded as suitable only for research applications and not for routine use. PMID:2671015

  11. 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

  12. Candida albicans mutant construction and characterization of selected virulence determinants.

    PubMed

    Motaung, T E; Albertyn, J; Pohl, C H; Köhler, Gerwald

    2015-08-01

    Candida albicans is a diploid, polymorphic yeast, associated with humans, where it mostly causes no harm. However, under certain conditions it can cause infections ranging from superficial to life threatening. This ability to become pathogenic is often linked to the immune status of the host as well as the expression of certain virulence factors by the yeast. Due to the importance of C. albicans as a pathogen, determination of the molecular mechanisms that allow this yeast to cause disease is important. These studies rely on the ability of researchers to create deletion mutants of specific genes in order to study their function. This article provides a critical review of the important techniques used to create deletion mutants in C. albicans and highlights how these deletion mutants can be used to determine the role of genes in the expression of virulence factors in vitro.

  13. O-mannosylation in Candida albicans enables development of interkingdom biofilm communities.

    PubMed

    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

    2014-04-15

    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. IMPORTANCE In the human mouth, microorganisms form communities known as biofilms that adhere to the surfaces present. Candida albicans is a fungus that is often found within these biofilms. We have focused on the mechanisms by which C. albicans becomes incorporated into communities containing bacteria, such as Streptococcus. We find that

  14. 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.

  15. 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. PMID:26891940

  16. 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.

  17. 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.

  18. The antimicrobial effects of selenium nanoparticle-enriched probiotics and their fermented broth against Candida albicans

    PubMed Central

    2014-01-01

    Background Lactic acid bacteria are considered important probiotics for prevention of some infections. The aim of this work was to investigate the effect of selenium dioxide on the antifungal activity of Lactobacillus plantarum and L. johnsonii against Candida albicans. Methods Lactobacillus plantarum and L. johnsonii cells, grown in the presence and absence of selenium dioxide, and their cell-free spent culture media were tested for antifungal activity against C. albicans ATCC 14053 by a hole-plate diffusion method and a time-kill assay. Results Both L. plantarum and L. johnsonii reduced selenium dioxide to cell-associated elemental selenium nanoparticles. The cell-free spent culture media, from both Lactobacillus species that had been grown with selenium dioxide for 48 h, showed enhanced antifungal activity against C. albicans. Enhanced antifungal activity of cell biomass against C. albicans was also observed in cultures grown with selenium dioxide. Conclusions Selenium dioxide-treated Lactobacillus spp. or their cell-free spent broth inhibited the growth of C. albicans and should be investigated for possible use in anti-Candida probiotic formulations in future. PMID:24906455

  19. Baicalein induces programmed cell death in Candida albicans.

    PubMed

    Dai, Bao-Di; Cao, Ying-Ying; Huang, Shan; Xu, Yong-Gang; Gao, Ping-Hui; Wang, Yan; Jiang, Yuan-Ying

    2009-08-01

    Recent evidence has revealed the occurrence of an apoptotic phenotype in Candida albicans that is inducible with environmental stresses such as acetic acid, hydrogen peroxide, and amphotericin B. In the present study, we found that the Chinese herbal medicine Baicalein (BE), which was one of the skullcapflavones, can induce apoptosis in C. albicans. The apoptotic effects of BE were detected by flow cytometry using Annexin V-FITC and DAPI, and it was confirmed by transmission electron microscopy analysis. After exposure to 4 microg/ml BE for 12 h, about 10% of C. albicans cells were apoptotic. Both the increasing intracellular levels of reactive oxygen species (ROS) and upregulation of some redox-related genes (CAP1, SOD2, TRR1) were observed. Furthermore, we compared the survivals of CAP1 deleted, wild-type, and overexpressed strains and found that Cap1p attenuated BE-initiated cell death, which was coherent with a higher mRNA level of the CAP1 gene. In addition, the mitochondrial membrane potential of C. albicans cells changed significantly ( p<0.001) upon BE treatment compared with control. Taken together, our results indicate that BE treatment induces apoptosis in C.albicans cells, and the apoptosis was associated with the breakdown of mitochondrial membrane potential. PMID:19734718

  20. Oxidative stress responses in the human fungal pathogen, Candida albicans.

    PubMed

    Dantas, Alessandra da Silva; 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. 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

  2. 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. PMID:26480336

  3. 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

  4. Cellular Components Mediating Coadherence of Candida albicans and Fusobacterium nucleatum.

    PubMed

    Wu, T; Cen, L; Kaplan, C; Zhou, X; Lux, R; Shi, W; He, X

    2015-10-01

    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.

  5. 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

  6. Identification of the cell targets important for propolis-induced cell death in Candida albicans.

    PubMed

    de Castro, Patrícia Alves; Bom, Vinícius Leite Pedro; Brown, Neil Andrew; de Almeida, Ricardo Sérgio Couto; Ramalho, Leandra Naira Zambelli; Savoldi, Marcela; Goldman, Maria Helena S; Berretta, Andresa A; Goldman, Gustavo Henrique

    2013-11-01

    Candida albicans is the most common fungal pathogen of humans, forming both commensal and opportunistic pathogenic interactions, causing a variety of skin and soft tissue infections in healthy people. In immunocompromised patients C. albicans can result in invasive, systemic infections that are associated with a high incidence of mortality. Propolis is a complex mixture of several resinous substances which are collected from plants by bees. Here, we demonstrated the fungicidal activity of propolis against all three morphogenetic types of C. albicans and that propolis-induced cell death was mediated via metacaspase and Ras signaling. To identify genes that were involved in propolis tolerance, we screened ~800 C. albicans homozygous deletion mutants for decreased tolerance to propolis. Fifty-one mutant strains were identified as being hypersensitive to propolis including seventeen genes involved in cell adhesion, biofilm formation, filamentous growth, phenotypic switching and pathogenesis (HST7, GIN4, VPS34, HOG1, ISW2, SUV3, MDS3, HDA2, KAR3, YHB1, NUP85, CDC10, MNN9, ACE2, FKH2, and SNF5). We validated these results by showing that propolis inhibited the transition from yeast-like to hyphal growth. Propolis was shown to contain compounds that conferred fluorescent properties to C. albicans cells. Moreover, we have shown that a topical pharmaceutical preparation, based upon propolis, was able to control C. albicans infections in a mouse model for vulvovaginal candidiasis. Our results strongly indicate that propolis could be used as a strategy for controlling candidiasis.

  7. Quorum Sensing in the Dimorphic Fungus Candida albicans Is Mediated by Farnesol

    PubMed Central

    Hornby, Jacob M.; Jensen, Ellen C.; Lisec, Amber D.; Tasto, Joseph J.; Jahnke, Brandon; Shoemaker, Richard; Dussault, Patrick; Nickerson, Kenneth W.

    2001-01-01

    The inoculum size effect in the dimorphic fungus Candida albicans results from production of an extracellular quorum-sensing molecule (QSM). This molecule prevents mycelial development in both a growth morphology assay and a differentiation assay using three chemically distinct triggers for germ tube formation (GTF): l-proline, N-acetylglucosamine, and serum (either pig or fetal bovine). In all cases, the presence of QSM prevents the yeast-to-mycelium conversion, resulting in actively budding yeasts without influencing cellular growth rates. QSM exhibits general cross-reactivity within C. albicans in that supernatants from strain A72 are active on five other strains of C. albicans and vice versa. The QSM excreted by C. albicans is farnesol (C15H26O; molecular weight, 222.37). QSM is extracellular, and is produced continuously during growth and over a temperature range from 23 to 43°C, in amounts roughly proportional to the CFU/milliliter. Production is not dependent on the type of carbon source nor nitrogen source or on the chemical nature of the growth medium. Both commercial mixed isomer and (E,E)-farnesol exhibited QSM activity (the ability to prevent GTF) at a level sufficient to account for all the QSM activity present in C. albicans supernatants, i.e., 50% GTF at ca. 30 to 35 μM. Nerolidol was ca. two times less active than farnesol. Neither geraniol (C10), geranylgeraniol (C20), nor farnesyl pyrophosphate had any QSM activity. PMID:11425711

  8. Candida albicans AGE3, the Ortholog of the S. cerevisiae ARF-GAP-Encoding Gene GCS1, Is Required for Hyphal Growth and Drug Resistance

    PubMed Central

    Lettner, Thomas; Zeidler, Ute; Gimona, Mario; Hauser, Michael; Breitenbach, Michael; Bito, Arnold

    2010-01-01

    Background Hyphal growth and multidrug resistance of C. albicans are important features for virulence and antifungal therapy of this pathogenic fungus. Methodology/Principal Findings Here we show by phenotypic complementation analysis that the C. albicans gene AGE3 is the functional ortholog of the yeast ARF-GAP-encoding gene GCS1. The finding that the gene is required for efficient endocytosis points to an important functional role of Age3p in endosomal compartments. Most C. albicans age3Δ mutant cells which grew as cell clusters under yeast growth conditions showed defects in filamentation under different hyphal growth conditions and were almost completely disabled for invasive filamentous growth. Under hyphal growth conditions only a fraction of age3Δ cells shows a wild-type-like polarization pattern of the actin cytoskeleton and lipid rafts. Moreover, age3Δ cells were highly susceptible to several unrelated toxic compounds including antifungal azole drugs. Irrespective of the AGE3 genotype, C-terminal fusions of GFP to the drug efflux pumps Cdr1p and Mdr1p were predominantly localized in the plasma membrane. Moreover, the plasma membranes of wild-type and age3Δ mutant cells contained similar amounts of Cdr1p, Cdr2p and Mdr1p. Conclusions/Significance The results indicate that the defect in sustaining filament elongation is probably caused by the failure of age3Δ cells to polarize the actin cytoskeleton and possibly of inefficient endocytosis. The high susceptibility of age3Δ cells to azoles is not caused by inefficient transport of efflux pumps to the cell membrane. A possible role of a vacuolar defect of age3Δ cells in drug susceptibility is proposed and discussed. In conclusion, our study shows that the ARF-GAP Age3p is required for hyphal growth which is an important virulence factor of C. albicans and essential for detoxification of azole drugs which are routinely used for antifungal therapy. Thus, it represents a promising antifungal drug target

  9. 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

  10. Effect of ferrocene-substituted porphyrin RL-91 on Candida albicans biofilm formation.

    PubMed

    Lippert, Rainer; Vojnovic, Sandra; Mitrovic, Aleksandra; Jux, Norbert; Ivanović-Burmazović, Ivana; Vasiljevic, Branka; Stankovic, Nada

    2014-08-01

    Ferrocene-substituted porphyrin RL-91 exhibits antifungal activity against opportune human pathogen Candida albicans. RL-91 efficiently inhibits growth of both planktonic C. albicans cells and cells within biofilms without photoactivation. The minimal inhibitory concentration for plankton form (PMIC) was established to be 100 μg/mL and the same concentration killed 80% of sessile cells in the mature biofilm (SMIC80). Furthermore PMIC of RL-91 efficiently prevents C. albicans biofilm formation. RL-91 is cytotoxic for human fibroblasts in vitro in concentration of 10 μg/mL, however it does not cause hemolysis in concentrations of up to 50 μg/mL. These findings open possibility for application of RL-91 as an antifungal agent for external antibiofilm treatment of medical devices as well as a scaffold for further development of porphyrin based systemic antifungals.

  11. D-Erythroascorbic acid activates cyanide-resistant respiration in Candida albicans.

    PubMed

    Huh, Won-Ki; Song, Yong Bhum; Lee, Young-Seok; Ha, Cheol Woong; Kim, Seong-Tae; Kang, Sa-Ouk

    2008-05-01

    Higher plants, protists and fungi possess cyanide-resistant respiratory pathway, which is mediated by alternative oxidase (AOX). The activity of AOX has been found to be dependent on several regulatory mechanisms including gene expression and posttranslational regulation. In the present study, we report that the presence of cyanide in culture medium remarkably retarded the growth of alo1/alo1 mutant of Candida albicans, which lacks d-arabinono-1,4-lactone oxidase (ALO) that catalyzes the final step of d-erythroascorbic acid (EASC) biosynthesis. Measurement of respiratory activity and Western blot analysis revealed that increase in the intracellular EASC level induces the expression of AOX in C. albicans. AOX could still be induced by antimycin A, a respiratory inhibitor, in the absence of EASC, suggesting that several factors may act in parallel pathways to induce the expression of AOX. Taken together, our results suggest that EASC plays important roles in activation of cyanide-resistant respiration in C. albicans.

  12. Innate Immunity and Saliva in Candida albicans-mediated Oral Diseases.

    PubMed

    Salvatori, O; Puri, S; Tati, S; Edgerton, M

    2016-04-01

    The oral cavity is a unique niche where Candida albicans infections occur in immunocompetent as well as immunosuppressed individuals. Here we critically review the significance of human innate immune response in preventing oral candidiasis. One important line of defense against oropharyngeal candidiasis is the oral microbiota that prevents infection by competing for space and nutrients as well as by secreting antagonistic molecules and triggering local inflammatory responses. C. albicans is able to induce mucosal defenses through activation of immune cells and production of cytokines. Also, saliva contains various proteins that affect C. albicans growth positively by promoting mucosal adherence and negatively through immune exclusion and direct fungicidal activity. We further discuss the role of saliva in unifying host innate immune defenses against C. albicans as a communicating medium and how C. albicans overgrowth in the oral cavity may be a result of aberrations ranging from microbial dysbiosis and salivary dysfunction to epithelial damage. Last we underscore select oral diseases in which C. albicans is a contributory microorganism in immune-competent individuals.

  13. 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

  14. Innate Immunity and Saliva in Candida albicans-mediated Oral Diseases.

    PubMed

    Salvatori, O; Puri, S; Tati, S; Edgerton, M

    2016-04-01

    The oral cavity is a unique niche where Candida albicans infections occur in immunocompetent as well as immunosuppressed individuals. Here we critically review the significance of human innate immune response in preventing oral candidiasis. One important line of defense against oropharyngeal candidiasis is the oral microbiota that prevents infection by competing for space and nutrients as well as by secreting antagonistic molecules and triggering local inflammatory responses. C. albicans is able to induce mucosal defenses through activation of immune cells and production of cytokines. Also, saliva contains various proteins that affect C. albicans growth positively by promoting mucosal adherence and negatively through immune exclusion and direct fungicidal activity. We further discuss the role of saliva in unifying host innate immune defenses against C. albicans as a communicating medium and how C. albicans overgrowth in the oral cavity may be a result of aberrations ranging from microbial dysbiosis and salivary dysfunction to epithelial damage. Last we underscore select oral diseases in which C. albicans is a contributory microorganism in immune-competent individuals. PMID:26747422

  15. 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. PMID:19246906

  16. 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

  17. 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.

  18. Factors supporting cysteine tolerance and sulfite production in Candida albicans.

    PubMed

    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; Staib, Peter

    2013-04-01

    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.

  19. 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.

  20. Histone deacetylase-mediated morphological transition in Candida albicans.

    PubMed

    Kim, Jueun; Lee, Ji-Eun; Lee, Jung-Shin

    2015-12-01

    Candida albicans is the most common opportunistic fungal pathogen, which switches its morphology from single-cell yeast to filament through the various signaling pathways responding to diverse environmental cues. Various transcriptional factors such as Nrg1, Efg1, Brg1, Ssn6, and Tup1 are the key components of these signaling pathways. Since C. albicans can regulate its transcriptional gene expressions using common eukaryotic regulatory systems, its morphological transition by these signaling pathways could be linked to the epigenetic regulation by chromatin structure modifiers. Histone proteins, which are critical components of eukaryotic chromatin structure, can regulate the eukaryotic chromatin structure through their own modifications such as acetylation, methylation, phosphorylation and ubiquitylation. Recent studies revealed that various histone modifications, especially histone acetylation and deacetylation, participate in morphological transition of C. albicans collaborating with well-known transcription factors in the signaling pathways. Here, we review recent studies about chromatin-mediated morphological transition of C. albicans focusing on the interaction between transcription factors in the signaling pathways and histone deacetylases.

  1. Detection of Candida albicans by mass spectrometric fingerprinting.

    PubMed

    Zehm, Sarah; Schweinitz, Simone; Würzner, Reinhard; Colvin, Hans Peter; Rieder, Josef

    2012-03-01

    Candida albicans is one of the most frequent causes of fungal infections in humans. Significant correlation between candiduria and invasive candidiasis has previously been described. The existing diagnostic methods are often time-consuming, cost-intensive and lack in sensitivity and specificity. In this study, the profile of low-molecular weight volatile compounds in the headspace of C. albicans-urine suspensions of four different fungal cell concentrations compared to nutrient media and urine without C. albicans was determined using proton-transfer reaction mass spectrometry (PTR-MS). At fungal counts of ≥1.5 × 10(5) colony forming units (CFU)/ml signals at 45, 47 and 73 atomic mass units (amu) highly significantly increased. At fungal counts of <1.5 × 10(5) CFU/ml signals at 47 and 73 amu also increased, but only at 45 amu a statistically significant increase was seen. Time course alterations of signal intensities dependent on different cell concentrations and after addition of Sabouraud nutrient solution were analysed. Recommendations for measurement conditions are given. Our study is the first to describe headspace profiling of C. albicans-urine suspensions of different fungal cell concentrations. PTR-MS represents a promising approach to rapid, highly sensitive and non-invasive clinical diagnostics allowing qualitative and quantitative analysis.

  2. Structure and regulation of the HSP90 gene from the pathogenic fungus Candida albicans.

    PubMed Central

    Swoboda, R K; Bertram, G; Budge, S; Gooday, G W; Gow, N A; Brown, A J

    1995-01-01

    Candida albicans HSP90 sequences were isolated by screening cDNA and genomic libraries with a probe derived from the Saccharomyces cerevisiae homolog, HSP82, which encodes a member of the heat shock protein 90 family of molecular chaperones. Identical sequences were obtained for the 2,197-bp overlap of the cDNA and gene sequences, which were derived from C. albicans 3153A and ATCC 10261, respectively. The C. albicans HSP90 gene contained no introns, and it showed strong homology (61 to 79% identity) to HSP90 sequences from other fungi, vertebrates, and plants. The C-terminal portion of the predicted Hsp90 amino acid sequence was identical to the 47-kDa protein which is thought to be immunoprotective during C. albicans infections (R. C. Matthews, J. Med. Microbiol. 36:367-370, 1992), confirming that this protein represents the C-terminal portion of the 81-kDa Hsp90 protein. Quantitative Northern (RNA) analyses revealed that C. albicans HSP90 mRNA was heat shock inducible and that its levels changed during batch growth, with its maximum levels being reached during the mid-exponential growth phase. HSP90 mRNA levels increased transiently during the yeast-to-hyphal transition but did not correlate directly with germ tube production per se. These data do not exclude a role for Hsp90 in the dimorphic transition. Southern blotting revealed only one HSP90 locus in the diploid C. albicans genome. Repeated attempts to disrupt both alleles and generate a homozygous C. albicans delta hsp90/delta hsp90 null mutant were unsuccessful. These observations suggest the existence of a single HSP90 locus which is essential for viability in C. albicans. PMID:7591093

  3. Low virulent oral Candida albicans strains isolated from smokers.

    PubMed

    de Azevedo Izidoro, Ana Claudia Santos; Semprebom, Andressa Marafon; Baboni, Fernanda Brasil; Rosa, Rosimeire Takaki; Machado, Maria Angela Naval; Samaranayake, Lakshman Perera; Rosa, Edvaldo Antonio Ribeiro

    2012-02-01

    It is widely accepted that tabagism is a predisposing factor to oral candidosis and cumulate data suggest that cigarette compounds may increase candidal virulence. To verify if enhanced virulence occurs in Candida albicans from chronic smokers, a cohort of 42 non-smokers and other of 58 smokers (all with excellent oral conditions and without signs of candidosis) were swabbed on tong dorsum and jugal mucosa. Results showed that oral candidal loads do not differ between smoker and non-smokers. Activities of secreted aspartyl-protease (Sap), phospholipase, chondroitinase, esterase-lipase, and haemolysin secretions were screened for thirty-two C. albicans isolates. There were detected significant increments in phospholipasic and chondroitinasic activities in isolates from non-smokers. For other virulence factors, no differences between both cohorts were achieved. PMID:21924704

  4. 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.

  5. Medical treatment of a pacemaker endocarditis due to Candida albicans and to Candida glabrata.

    PubMed

    Roger, P M; Boissy, C; Gari-Toussaint, M; Foucher, R; Mondain, V; Vandenbos, F; le Fichoux, Y; Michiels, J F; Dellamonica, P

    2000-09-01

    We describe a case of pacemaker infection due to two fungal species: Candida albicans and C. glabrata. Transthoracic echocardiography showed a large vegetation on the intraventricular wires. Because of severe underlying diseases, surgery was believed to be contraindicated. The patient was treated using high dose of fluconazole, resulting in clinical improvement and negative blood cultures. However, 2 months later, the patient underwent a fatal stroke. At autopsy, a large vegetation was found only all along the wires. Postmortem culture of the infected material was positive for both C. albicans and C. glabrata. PMID:11023765

  6. [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.

  7. 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

  8. Interactions between amphotericin B and nitroimidazoles against Candida albicans.

    PubMed

    Cury, A E; Hirschfeld, M P

    1997-10-01

    This work proved that nitroimidazole antiprotozoal agents, such as metronidazole, ornidazole, secnidazole and tinidazole, in concentrations of up to 64 micrograms ml-1 did not present any antifungal activity against 17 strains of Candida albicans. The combination of each drug with amphotericin B showed the occurrence of variable interactions according to the studied strain. Promising results were observed based on synergistic and additive interactions of the polyene with the metronidazole; the inhibitory and lethal activities of the drugs were potentiated against all strains in concentrations reachable in vivo. PMID:9476486

  9. Protective and pathologic immune responses against Candida albicans infection.

    PubMed

    Ashman, Robert B

    2008-05-01

    Candida albicans is an important opportunistic fungal pathogen. Clinical observations have indicated that both innate and adaptive immune responses are involved in recovery from initial infection, but analysis in murine models has shown that the contribution of the two arms of the cellular immune response differ in oral, vaginal, and systemic infections. The relative contributions of T cells and phagocytic cells, and the cytokines that mediate their interactions are discussed for each of the different manifestations of the disease, and the consequences of infection, in terms of protection and pathology, are evaluated.

  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. 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

  12. Systemic Candida albicans infection in two alpacas (Lama pacos).

    PubMed

    Kramer, K; Haist, V; Roth, C; Schröder, C; Siesenhop, U; Baumgärtner, W; Wohlsein, P

    2008-01-01

    Systemic Candida albicans infection was diagnosed in two adult alpaca stallions originating from different herds. Case 1 had a history of chronic dermatitis with unknown aetiology that had been treated long-term with glucocorticoids. Case 2 had suffered from transient facial paralysis and psoroptic mange of the external ear. Both animals died suddenly after recovering from their initial disorders. Necropsy examination of case 1 revealed multifocal erosive dermatitis, thoracic and abdominal serofibrinous effusions, and multiple suppurative foci in lung, myocardium, kidney, pancreas and brain. Case 2 had multiple ulcers of the third gastric compartment and focal suppurative nephritis. Additionally, moderate depletion of lymphoid organs was observed in both animals. Histologically, suppurative to necrotizing inflammation with necrotizing vasculitis was present in the grossly affected organs of both animals. Yeast, pseudohyphae and branching hyphae were present within these lesions and C. albicans was isolated from lesional tissue of both animals. The primary site of Candida invasion was not determined in case 1, but the most likely portal of entry in case 2 was the gastric ulcers. Depletion of lymphoid tissue suggested a possible underlying immune suppression in both animals.

  13. The ABCs of Candida albicans Multidrug Transporter Cdr1

    PubMed Central

    Banerjee, Atanu; Khandelwal, Nitesh Kumar; Dhamgaye, Sanjiveeni

    2015-01-01

    In the light of multidrug resistance (MDR) among pathogenic microbes and cancer cells, membrane transporters have gained profound clinical significance. Chemotherapeutic failure, by far, has been attributed mainly to the robust and diverse array of these proteins, which are omnipresent in every stratum of the living world. Candida albicans, one of the major fungal pathogens affecting immunocompromised patients, also develops MDR during the course of chemotherapy. The pivotal membrane transporters that C. albicans has exploited as one of the strategies to develop MDR belongs to either the ATP binding cassette (ABC) or the major facilitator superfamily (MFS) class of proteins. The ABC transporter Candida drug resistance 1 protein (Cdr1p) is a major player among these transporters that enables the pathogen to outplay the battery of antifungals encountered by it. The promiscuous Cdr1 protein fulfills the quintessential need of a model to study molecular mechanisms of multidrug transporter regulation and structure-function analyses of asymmetric ABC transporters. In this review, we cover the highlights of two decades of research on Cdr1p that has provided a platform to study its structure-function relationships and regulatory circuitry for a better understanding of MDR not only in yeast but also in other organisms. PMID:26407965

  14. SOME CYTOLOGICAL AND PATHOGENIC PROPERTIES OF SPHEROPLASTS OF CANDIDA ALBICANS

    PubMed Central

    Kobayashi, George S.; Friedman, Lorraine; Kofroth, Judith F.

    1964-01-01

    Kobayashi, George S. (Tulane University, New Orleans, La.), Lorraine Friedman, and Judith F. Kofroth. Some cytological and pathogenic properties of spheroplasts of Candida albicans. J. Bacteriol. 88:795–801. 1964.—Spheroplasts of Candida albicans were prepared by use of an enzymatic mixture from the digestive tract of the snail Helix pomatia. Untreated cells exhibited well-defined cell walls, whereas such structures were absent from spheroplasts. The intravenous inoculation of either spheroplasts or intact cells into rabbits produced a fever which was apparent within 30 min, the “immediate” fever response characteristic of microbial endotoxin. Cell-wall fragments of enzyme-treated cells did not induce a convincing pyrogenic response. When the inoculum was viable, body temperatures did not return to normal but remained elevated until death of the animal 1 or more days later, exhibiting the “delayed” fever of infection. The gross pathological picture in animals succumbing to infection by viable spheroplasts was similar to that obtained with untreated yeast cells. Images PMID:14208520

  15. 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.

  16. 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.

  17. 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.

  18. Superantigen-Like Effects of a Candida albicans Polypeptide

    PubMed Central

    Devore-Carter, Denise; Kar, Sujata; Vellucci, Vincent; Bhattacherjee, Vasker; Domanski, Paul; Hostetter, Margaret K.

    2008-01-01

    The amino terminal sequence of the Candida albicans cell wall protein Int1 exhibited partial identity with the major histocompatibility complex (MHC) class II binding site of the Mycoplasma arthritidis superantigen MAM. Int1-positive C. albicans blastospores activated human T lymphocytes and expanded Vβ subsets 2, 3, and/or 14; Int1-negative strains were inactive. Release of interferon-γ (IFN-γ) but not of tumor necrosis factor–α or interleukin-6 was Int1 dependent; interleukin-4 and interleukin-10 were not detected. T lymphocyte activation, Vβ expansion, and IFN-γ release were associated with a soluble polypeptide that encompassed the first 263 amino acids of Int1 (Pep263). Monoclonal antibody 163.5, which recognizes an Int1 epitope that overlaps the region of identity with MAM, significantly inhibited these activities when triggered by Int1-positive blastospores or Pep263 but not by staphylococcal enterotoxin B. Histidine263 was required. Pep263 bound to T lymphocytes and MHC class II and was detected in the urine of a patient with C. albicans fungemia. These studies identify a candidal protein that displays superantigen-like activities. PMID:18419534

  19. 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

  20. Vaginal epithelial cell anti-Candida albicans activity is associated with protection against symptomatic vaginal candidiasis.

    PubMed

    Barousse, Melissa M; Espinosa, Terri; Dunlap, Kathleen; Fidel, Paul L

    2005-11-01

    Vaginal epithelial cell (VEC) anti-Candida albicans activity, despite being measured in vitro, is considered an innate host defense mechanism. This was supported further by the fact that women protected from symptomatic infection following a live intravaginal Candida challenge had increased VEC anti-Candida activity compared to those who acquired a symptomatic infection.

  1. 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.

  2. β-Asarone, an active principle of Acorus calamus rhizome, inhibits morphogenesis, biofilm formation and ergosterol biosynthesis in Candida albicans.

    PubMed

    Rajput, Sandeep B; Karuppayil, S Mohan

    2013-01-15

    Anti-Candida potential of Acorus calamus rhizome and its active principle, β-asarone, was evaluated against the human fungal pathogen, Candida albicans. β-Asarone exhibited promising growth inhibitory activity at 0.5mg/ml and it was fungicidal at 8 mg/ml. Time dependant kill curve assay showed that MFC of β-asarone was highly toxic to C. albicans, killing 99.9% inoculum within 120 min of exposure. β-Asarone caused significant inhibition of C. albicans morphogenesis and biofilm development at sub-inhibitory concentrations. Our data indicate that the growth inhibitory activity of β-asarone might be through inhibition of ergosterol biosynthesis. Hemolytic assay showed that β-asarone is non-toxic, even at concentrations approaching MIC value. Our results suggest that β-asarone may be safe as a topical antifungal agent. PMID:23123225

  3. Activity of Novel Synthetic Peptides against Candida albicans.

    PubMed

    Lum, Kah Yean; Tay, Sun Tee; Le, Cheng Foh; Lee, Vannajan Sanghiran; Sabri, Nadia Hanim; Velayuthan, Rukumani Devi; Hassan, Hamimah; Sekaran, Shamala Devi

    2015-01-01

    Candida spp. are the most common causes of fungal infections worldwide. Among the Candida species, Candida albicans remains the predominant species that causes invasive candidiasis in most countries. In this study, we used two peptides, KABT-AMP and uperin 3.6 as templates to develop novel antifungal peptides. Their anticandidal activity was assessed using a combination of MIC, time-killing assay and biofilm reduction assay. Hybrid peptides, KU2 and KU3 containing a mixed backbone of KABT-AMP and Uperin 3.6 demonstrated the most potent anticandidal activity with MIC values ranging from 8-16 mg/L. The number of Trp residues and the amphipathic structure of peptides probably enhanced the anticandidal activity of peptides. Increasing the cationicity of the uperin 3.6 analogues resulted in reduced MIC from the range of 64-128 mg/L to 16-64 mg/L and this was also correlated with the antibiofilm activity and killing kinetics of the peptides. Peptides showed synergistic effects when used in combination with conventional antifungals. Peptides demonstrated low haemolytic activity but significant toxicity on two normal human epithelial cell lines. This study provides us with a better understanding on the structure-activity relationship and the balance between cationicity and hydrophobicity of the peptides although the therapeutic application of the peptides is limited. PMID:25965506

  4. Flavodoxin-Like Proteins Protect Candida albicans from Oxidative Stress and Promote Virulence.

    PubMed

    Li, Lifang; Naseem, Shamoon; Sharma, Sahil; Konopka, James B

    2015-09-01

    The fungal pathogen Candida albicans causes lethal systemic infections in humans. To better define how pathogens resist oxidative attack by the immune system, we examined a family of four Flavodoxin-Like Proteins (FLPs) in C. albicans. In agreement with previous studies showing that FLPs in bacteria and plants act as NAD(P)H quinone oxidoreductases, a C. albicans quadruple mutant lacking all four FLPs (pst1Δ, pst2Δ, pst3Δ, ycp4Δ) was more sensitive to benzoquinone. Interestingly, the quadruple mutant was also more sensitive to a variety of oxidants. Quinone reductase activity confers important antioxidant effects because resistance to oxidation was restored in the quadruple mutant by expressing either Escherichia coli wrbA or mammalian NQO1, two distinct types of quinone reductases. FLPs were detected at the plasma membrane in C. albicans, and the quadruple mutant was more sensitive to linolenic acid, a polyunsaturated fatty acid that can auto-oxidize and promote lipid peroxidation. These observations suggested that FLPs reduce ubiquinone (coenzyme Q), enabling it to serve as an antioxidant in the membrane. In support of this, a C. albicans coq3Δ mutant that fails to synthesize ubiquinone was also highly sensitive to oxidative stress. FLPs are critical for survival in the host, as the quadruple mutant was avirulent in a mouse model of systemic candidiasis under conditions where infection with wild type C. albicans was lethal. The quadruple mutant cells initially grew well in kidneys, the major site of C. albicans growth in mice, but then declined after the influx of neutrophils and by day 4 post-infection 33% of the mice cleared the infection. Thus, FLPs and ubiquinone are important new antioxidant mechanisms that are critical for fungal virulence. The potential of FLPs as novel targets for antifungal therapy is further underscored by their absence in mammalian cells. PMID:26325183

  5. 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.

  6. 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.

  7. 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

  8. 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. PMID:26162470

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. Ecology of Candida albicans gut colonization: inhibition of Candida adhesion, colonization, and dissemination from the gastrointestinal tract by bacterial antagonism.

    PubMed Central

    Kennedy, M J; Volz, P A

    1985-01-01

    Antibiotic-treated and untreated Syrian hamsters were inoculated intragastrically with Candida albicans to determine whether C. albicans could opportunistically colonize the gastrointestinal tract and disseminate to visceral organs. Antibiotic treatment decreased the total population levels of the indigenous bacterial flora and predisposed hamsters to gastrointestinal overgrowth and subsequent systemic dissemination by C. albicans in 86% of the animals. Both control hamsters not given antibiotics and antibiotic-treated animals reconventionalized with an indigenous microflora showed significantly lower gut populations of C. albicans, and C. albicans organisms were cultured from the visceral organs of 0 and 10% of the animals, respectively. Conversely, non-antibiotic-treated hamsters inoculated repeatedly with C. albicans had high numbers of C. albicans in the gut, and viable C. albicans was recovered from the visceral organs of 53% of the animals. Examination of the mucosal surfaces from test and control animals indicated further that animals which contained a complex indigenous microflora had significantly lower numbers of C. albicans associated with their gut walls than did antibiotic-treated animals. The ability of C. albicans to associate with intestinal mucosal surfaces also was tested by an in vitro adhesion assay. The results indicate that the indigenous microflora reduced the mucosal association of C. albicans by forming a dense layer of bacteria in the mucus gel, out-competing yeast cells for adhesion sites, and producing inhibitor substances (possibly volatile fatty acids, secondary bile acids, or both) that reduced C. albicans adhesion. It is suggested, therefore, that the indigenous intestinal microflora suppresses C. albicans colonization and dissemination from the gut by inhibiting Candida-mucosal association and reducing C. albicans population levels in the gut. Images PMID:3897061

  14. MIG1 Regulates Resistance of Candida albicans against the Fungistatic Effect of Weak Organic Acids.

    PubMed

    Cottier, Fabien; Tan, Alrina Shin Min; Xu, Xiaoli; Wang, Yue; Pavelka, Norman

    2015-10-01

    Candida albicans is the leading cause of fungal infections; but it is also a member of the human microbiome, an ecosystem of thousands of microbial species potentially influencing the outcome of host-fungal interactions. Accordingly, antibacterial therapy raises the risk of candidiasis, yet the underlying mechanism is currently not fully understood. We hypothesize the existence of bacterial metabolites that normally control C. albicans growth and of fungal resistance mechanisms against these metabolites. Among the most abundant microbiota-derived metabolites found on human mucosal surfaces are weak organic acids (WOAs), such as acetic, propionic, butyric, and lactic acid. Here, we used quantitative growth assays to investigate the dose-dependent fungistatic properties of WOAs on C. albicans growth and found inhibition of growth to occur at physiologically relevant concentrations and pH values. This effect was conserved across distantly related fungal species both inside and outside the CTG clade. We next screened a library of transcription factor mutants and identified several genes required for the resistance of C. albicans to one or more WOAs. A single gene, MIG1, previously known for its role in glucose repression, conferred resistance against all four acids tested. Consistent with glucose being an upstream activator of Mig1p, the presence of this carbon source was required for WOA resistance in wild-type C. albicans. Conversely, a MIG1-complemented strain completely restored the glucose-dependent resistance against WOAs. We conclude that Mig1p plays a central role in orchestrating a transcriptional program to fight against the fungistatic effect of this class of highly abundant metabolites produced by the gastrointestinal tract microbiota. PMID:26297702

  15. An Expanded Regulatory Network Temporally Controls Candida albicans Biofilm Formation

    PubMed Central

    Fox, Emily P.; Bui, Catherine K.; Nett, Jeniel E.; Hartooni, Nairi; Mui, Michael M.; Andes, David R.; Nobile, Clarissa J.; Johnson, Alexander D.

    2015-01-01

    Summary Candida albicans biofilms are composed of highly adherent and densely arranged cells with properties distinct from those of free-floating (planktonic) cells. These biofilms are a significant medical problem because they commonly form on implanted medical devices, are drug resistant, and are difficult to remove. C. albicans biofilms are not static structures; rather they are dynamic and develop over time. Here we characterize gene expression in biofilms during their development, and by comparing them to multiple planktonic reference states, we identify patterns of gene expression relevant to biofilm formation. In particular, we document time-dependent changes in genes involved in adhesion and metabolism, both of which are at the core of biofilm development. Additionally, we identify three new regulators of biofilm formation, Flo8, Gal4, and Rfx2, which play distinct roles during biofilm development over time. Flo8 is required for biofilm formation at all timepoints, and Gal4 and Rfx2 are needed for proper biofilm formation at intermediate time points. PMID:25784162

  16. An expanded regulatory network temporally controls Candida albicans biofilm formation.

    PubMed

    Fox, Emily P; Bui, Catherine K; Nett, Jeniel E; Hartooni, Nairi; Mui, Michael C; Andes, David R; Nobile, Clarissa J; Johnson, Alexander D

    2015-06-01

    Candida albicans biofilms are composed of highly adherent and densely arranged cells with properties distinct from those of free-floating (planktonic) cells. These biofilms are a significant medical problem because they commonly form on implanted medical devices, are drug resistant and are difficult to remove. C. albicans biofilms are not static structures; rather they are dynamic and develop over time. Here we characterize gene expression in biofilms during their development, and by comparing them to multiple planktonic reference states, we identify patterns of gene expression relevant to biofilm formation. In particular, we document time-dependent changes in genes involved in adhesion and metabolism, both of which are at the core of biofilm development. Additionally, we identify three new regulators of biofilm formation, Flo8, Gal4, and Rfx2, which play distinct roles during biofilm development over time. Flo8 is required for biofilm formation at all time points, and Gal4 and Rfx2 are needed for proper biofilm formation at intermediate time points.

  17. Scolopendin 2 leads to cellular stress response in Candida albicans.

    PubMed

    Lee, Heejeong; Hwang, Jae-Sam; Lee, Dong Gun

    2016-07-01

    Centipedes, a kind of arthropod, have been reported to produce antimicrobial peptides as part of an innate immune response. Scolopendin 2 (AGLQFPVGRIGRLLRK) is a novel antimicrobial peptide derived from the body of the centipede Scolopendra subspinipes mutilans by using RNA sequencing. To investigate the intracellular responses induced by scolopendin 2, reactive oxygen species (ROS) and glutathione accumulation and lipid peroxidation were monitored over sublethal and lethal doses. Intracellular ROS and antioxidant molecule levels were elevated and lipids were peroxidized at sublethal concentrations. Moreover, the Ca(2+) released from the endoplasmic reticulum accumulated in the cytosol and mitochondria. These stress responses were considered to be associated with yeast apoptosis. Candida albicans cells exposed to scolopendin 2 were identified using diagnostic markers of apoptotic response. Various responses such as phosphatidylserine externalization, chromatin condensation, and nuclear fragmentation were exhibited. Scolopendin 2 disrupted the mitochondrial membrane potential and activated metacaspase, which was mediated by cytochrome c release. In conclusion, treatment of C. albicans with scolopendin 2 induced the apoptotic response at sublethal doses, which in turn led to mitochondrial dysfunction, metacaspase activation, and cell death. The cationic antimicrobial peptide scolopendin 2 from the centipede is a potential antifungal peptide, triggering the apoptotic response. PMID:27207682

  18. [Anti-Candida albicans activity of essential oils including Lemongrass (Cymbopogon citratus) oil and its component, citral].

    PubMed

    Abe, Shigeru; Sato, Yuichi; Inoue, Shigeharu; Ishibashi, Hiroko; Maruyama, Naho; Takizawa, Toshio; Oshima, Haruyuki; Yamaguchi, Hideyo

    2003-01-01

    The effects of 12 essential oils, popularly used as antifungal treatments in aromatherapy, on growth of Candida albicans were investigated. Mycelial growth of C. albicans, which is known to give the fungus the capacity to invade mucosal tissues, was inhibited in the medium containing 100 micro g/ml of the oils: lemongrass (Cymbopogon citratus), thyme (Thymus vulgaris), patchouli (Pogostemon cablin) and cedarwood (Cedrus atlantica). Not only lemongrass oil but also citral, a major component of lemongrass oil (80%), in the range of 25 and 200 micro g/ml inhibited the mycelial growth but allowed yeast-form growth. More than 200 micro g/ml of citral clearly inhibited both mycelial and yeast-form growth of C. albicans. These results provide experimental evidence suggesting the potential value of lemongrass oil for the treatment of oral or vaginal candidiasis.

  19. Comparison of the in vitro activity of echinocandins against Candida albicans, Candida dubliniensis, and Candida africana by time-kill curves.

    PubMed

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

    2015-05-01

    Candida albicans remains the most common fungal pathogen. This species is closely related to 2 phenotypically similar cryptic species, Candida dubliniensis and Candida africana. This study aims to compare the antifungal activities of echinocandins against 7 C. albicans, 5 C. dubliniensis, and 2 C. africana strains by time-kill methodology. MIC values were similar for the 3 species; however, differences in killing activity were observed among species, isolates, and echinocandins. Echinocandins produced weak killing activity against the 3 species. In all drugs, the fungicidal endpoint (99.9% mortality) was reached at ≤31 h with ≥0.5 μg/mL for anidulafungin in 4 C. albicans and 1 C. dubliniensis, for caspofungin in 1 C. albicans and 2 C. dubliniensis, and for micafungin in 4 C. albicans and 1 C. dubliniensis. None of echinocandins showed lethality against C. africana. Identification of these new cryptic species and time-kill studies would be recommendable when echinocandin treatment fails.

  20. A patient with allergic bronchopulmonary mycosis caused by Aspergillus fumigatus and Candida albicans.

    PubMed

    Wardhana; Datau, E A

    2012-10-01

    Allergic Bronchopulmonary Mycosis (ABPM) is an exagregated immunologic response to fungal colonization in the lower airways. It may cause by many kinds of fungal, but Aspergillus fumigatus is the most common cause of ABPM, although other Aspergillus and other fungal organisms, like Candida albicans, have been implicated. Aspergllus fumigatus and Candida albicans may be found as outdoor and indoor fungi, and cause the sensitization, elicitation of the disease pathology, and its clinical manifestations. Several diagnostic procedurs may be impicated to support the diagnosis of ABPM caused by Aspergillus fumigatus and Candida albicans. A case of allergic bronchopulmonary mycosis caused by Aspergillus fumigatus and Candida albicans in a 48 year old man was discussed. The patient was treated with antifungal, corticosteroids, and antibiotic for the secondary bacterial infection. The patient's condition is improved without any significant side effects. PMID:23314973

  1. [Examination of the genetic variability among biofilm-forming Candida albicans clinical isolates].

    PubMed

    Durán, Estela Liliana; Mujica, Maria Teresa; Jewtuchowicz, Virginia Marta; Finquelievich, Jorge Luis; Pinoni, Maria Victoria; Iovannitti, Cristina Adela

    2007-12-31

    Biofilms are microbial communities encased in a self-produced polymeric matrix and represent a common mode of microbial growth. Candida albicans is able to colonize the surface of catheters, prostheses, and epithelia, forming biofilms that are highly resistant to antimicrobial drugs. The objective of this study was the genotypic characterization of biofilm-forming C. albicans clinical isolates using RAPD (Random Amplified Polymorphic DNA). We have studied 25 clinical isolates of C. albicans from oral cavities, blood, skin, nail, stool, oesophagus biopsy and vaginal fluids from patients suffering from candidiasis. For each strain biofilm formation was analysed by measuring the ability to adhere to and grow on polystyrene plastic surfaces using XTT [2,3-bis(2-methoxi-4nitro-5sulfophenil)-2H tetrazolium-5carboxanilide] reduction assay. The similarity coefficients generated by RAPD using four different primers varied from 49 to 91%, indicating a high degree of genetic variability between the clinical isolates. The dendrogram clustered the isolates in four related groups, all groups included strains with very different abilities to form biofilms. The isolates with similar genotypes often showed very different biofilm formation abilities. Strains were grouped into clusters independently of their clinical sources. Our results suggested that a direct correlation does not exist between the biofilm-forming ability of natural populations of C. albicans and the genotype as determined by RAPD.

  2. Antifungal effects of undecylenic acid on the biofilm formation of Candida albicans.

    PubMed

    Shi, Dongmei; Zhao, Yaxin; Yan, Hongxia; Fu, Hongjun; Shen, Yongnian; Lu, Guixia; Mei, Huan; Qiu, Ying; Li, Dongmei; Liu, Weida

    2016-05-01

    Undecylenic acid can effectively control skin fungal infection, but the mechanism of its fungal inhibition is unclear. Hyphal growth of Candida albicans (C. albicans) and biofilm formation have been well recognized as important virulence factors for the initiation of skin infection and late development of disseminated infection. In this study, we seek to investigate antifungal mechanisms of undecylenic acid by evaluating the virulence factors of C. albicans during biofilm formation. We found that undecylenic acid inhibits biofilm formation of C. albicans effectively with optimal concentration above 3 mM. In the presence of this compound, the morphological transition from yeast to filamentous phase is abolished ultimately when the concentration of undecylenic acid is above 4 mM. Meanwhile, the cell surface is crumpled, and cells display an atrophic appearance under scanning electron microscopy even with low concentration of drug treatment. On the other hand, the drug treatment decreases the transcriptions of hydrolytic enzymes such as secreted aspartic protease, lipase, and phospholipase. Hyphal formation related genes, like HWP1, are significantly reduced in transcriptional level in drug-treated biofilm condition as well. The down-regulated profile of these genes leads to a poorly organized biofilm in undecylenic acid treated environment.

  3. Antifungal effects of undecylenic acid on the biofilm formation of Candida albicans.

    PubMed

    Shi, Dongmei; Zhao, Yaxin; Yan, Hongxia; Fu, Hongjun; Shen, Yongnian; Lu, Guixia; Mei, Huan; Qiu, Ying; Li, Dongmei; Liu, Weida

    2016-05-01

    Undecylenic acid can effectively control skin fungal infection, but the mechanism of its fungal inhibition is unclear. Hyphal growth of Candida albicans (C. albicans) and biofilm formation have been well recognized as important virulence factors for the initiation of skin infection and late development of disseminated infection. In this study, we seek to investigate antifungal mechanisms of undecylenic acid by evaluating the virulence factors of C. albicans during biofilm formation. We found that undecylenic acid inhibits biofilm formation of C. albicans effectively with optimal concentration above 3 mM. In the presence of this compound, the morphological transition from yeast to filamentous phase is abolished ultimately when the concentration of undecylenic acid is above 4 mM. Meanwhile, the cell surface is crumpled, and cells display an atrophic appearance under scanning electron microscopy even with low concentration of drug treatment. On the other hand, the drug treatment decreases the transcriptions of hydrolytic enzymes such as secreted aspartic protease, lipase, and phospholipase. Hyphal formation related genes, like HWP1, are significantly reduced in transcriptional level in drug-treated biofilm condition as well. The down-regulated profile of these genes leads to a poorly organized biofilm in undecylenic acid treated environment. PMID:26902505

  4. In Vitro and In Vivo Antifungal Activity of Lichochalcone-A against Candida albicans Biofilms

    PubMed Central

    Seleem, Dalia; Benso, Bruna; Noguti, Juliana; Pardi, Vanessa; Murata, Ramiro Mendonça

    2016-01-01

    Oral candidiasis (OC) is an opportunistic fungal infection with high prevalence among immunocompromised patients. Candida albicans is the most common fungal pathogen responsible for OC, often manifested in denture stomatitis and oral thrush. Virulence factors, such as biofilms formation and secretion of proteolytic enzymes, are key components in the pathogenicity of C. albicans. Given the limited number of available antifungal therapies and the increase in antifungal resistance, demand the search for new safe and effective antifungal treatments. Lichochalcone-A is a polyphenol natural compound, known for its broad protective activities, as an antimicrobial agent. In this study, we investigated the antifungal activity of lichochalcone-A against C. albicans biofilms both in vitro and in vivo. Lichochalcone-A (625 μM; equivalent to 10x MIC) significantly reduced C. albicans (MYA 2876) biofilm growth compared to the vehicle control group (1% ethanol), as indicated by the reduction in the colony formation unit (CFU)/ml/g of biofilm dry weight. Furthermore, proteolytic enzymatic activities of proteinases and phospholipases, secreted by C. albicans were significantly decreased in the lichochalcone-A treated biofilms. In vivo model utilized longitudinal imaging of OC fungal load using a bioluminescent-engineered C. albicans (SKCa23-ActgLUC) and coelenterazine substrate. Mice treated with lichochalcone-A topical treatments exhibited a significant reduction in total photon flux over 4 and 5 days post-infection. Similarly, ex vivo analysis of tongue samples, showed a significant decrease in CFU/ml/mg in tongue tissue sample of lichochalcone-A treated group, which suggest the potential of lichochalcone-A as a novel antifungal agent for future clinical use. PMID:27284694

  5. In Vitro and In Vivo Activities of Pterostilbene against Candida albicans Biofilms

    PubMed Central

    Li, De-Dong; Zhao, Lan-Xue; Mylonakis, Eleftherios; Hu, Gan-Hai; Zou, Yong; Huang, Tong-Kun; Yan, Lan

    2014-01-01

    Pterostilbene (PTE) is a stilbene-derived phytoalexin that originates from several natural plant sources. In this study, we evaluated the activity of PTE against Candida albicans biofilms and explored the underlying mechanisms. In 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assays, biofilm biomass measurement, confocal laser scanning microscopy, and scanning electron microscopy, we found that ≤16 μg/ml PTE had a significant effect against C. albicans biofilms in vitro, while it had no fungicidal effect on planktonic C. albicans cells, which suggested a unique antibiofilm effect of PTE. Then we found that PTE could inhibit biofilm formation and destroy the maintenance of mature biofilms. At 4 μg/ml, PTE decreased cellular surface hydrophobicity (CSH) and suppressed hyphal formation. Gene expression microarrays and real-time reverse transcription-PCR showed that exposure of C. albicans to 16 μg/ml PTE altered the expression of genes that function in morphological transition, ergosterol biosynthesis, oxidoreductase activity, and cell surface and protein unfolding processes (heat shock proteins). Filamentation-related genes, especially those regulated by the Ras/cyclic AMP (cAMP) pathway, including ECE1, ALS3, HWP1, HGC1, and RAS1 itself, were downregulated upon PTE treatment, indicating that the antibiofilm effect of PTE was related to the Ras/cAMP pathway. Then, we found that the addition of exogenous cAMP reverted the PTE-induced filamentous growth defect. Finally, with a rat central venous catheter infection model, we confirmed the in vivo activity of PTE against C. albicans biofilms. Collectively, PTE had strong activities against C. albicans biofilms both in vitro and in vivo, and these activities were associated with the Ras/cAMP pathway. PMID:24514088

  6. In Vitro and In Vivo Antifungal Activity of Lichochalcone-A against Candida albicans Biofilms.

    PubMed

    Seleem, Dalia; Benso, Bruna; Noguti, Juliana; Pardi, Vanessa; Murata, Ramiro Mendonça

    2016-01-01

    Oral candidiasis (OC) is an opportunistic fungal infection with high prevalence among immunocompromised patients. Candida albicans is the most common fungal pathogen responsible for OC, often manifested in denture stomatitis and oral thrush. Virulence factors, such as biofilms formation and secretion of proteolytic enzymes, are key components in the pathogenicity of C. albicans. Given the limited number of available antifungal therapies and the increase in antifungal resistance, demand the search for new safe and effective antifungal treatments. Lichochalcone-A is a polyphenol natural compound, known for its broad protective activities, as an antimicrobial agent. In this study, we investigated the antifungal activity of lichochalcone-A against C. albicans biofilms both in vitro and in vivo. Lichochalcone-A (625 μM; equivalent to 10x MIC) significantly reduced C. albicans (MYA 2876) biofilm growth compared to the vehicle control group (1% ethanol), as indicated by the reduction in the colony formation unit (CFU)/ml/g of biofilm dry weight. Furthermore, proteolytic enzymatic activities of proteinases and phospholipases, secreted by C. albicans were significantly decreased in the lichochalcone-A treated biofilms. In vivo model utilized longitudinal imaging of OC fungal load using a bioluminescent-engineered C. albicans (SKCa23-ActgLUC) and coelenterazine substrate. Mice treated with lichochalcone-A topical treatments exhibited a significant reduction in total photon flux over 4 and 5 days post-infection. Similarly, ex vivo analysis of tongue samples, showed a significant decrease in CFU/ml/mg in tongue tissue sample of lichochalcone-A treated group, which suggest the potential of lichochalcone-A as a novel antifungal agent for future clinical use. PMID:27284694

  7. Assessment of antifungal activity of herbal and conventional toothpastes against clinical isolates of Candida albicans

    PubMed Central

    Adwan, Ghaleb; Salameh, Yousef; Adwan, Kamel; Barakat, Ali

    2012-01-01

    Objective To detect the anticandidal activity of nine toothpastes containing sodium fluoride, sodium monofluorophosphate and herbal extracts as an active ingredients against 45 oral and non oral Candida albicans (C. albicans) isolates. Methods The antifungal activity of these toothpaste formulations was determined using a standard agar well diffusion method. Statistical analysis was performed using a statistical package, SPSS windows version 15, by applying mean values using one-way ANOVA with post-hoc least square differences (LSD) method. A P value of less than 0.05 was considered significant. Results All toothpastes studied in our experiments were effective in inhibiting the growth of all C. albicans isolates. The highest anticandidal activity was obtained from toothpaste that containing both herbal extracts and sodium fluoride as active ingredients, while the lowest activity was obtained from toothpaste containing sodium monofluorophosphate as an active ingredient. Antifungal activity of Parodontax toothpaste showed a significant difference (P< 0.001) against C. albicans isolates compared to toothpastes containing sodium fluoride or herbal products. Conclusions In the present study, it has been demonstrated that toothpaste containing both herbal extracts and sodium fluoride as active ingredients are more effective in control of C. albicans, while toothpaste that containing monofluorophosphate as an active ingredient is less effective against C. albicans. Some herbal toothpaste formulations studied in our experiments, appear to be equally effective as the fluoride dental formulations and it can be used as an alternative to conventional formulations for individuals who have an interest in naturally-based products. Our results may provide invaluable information for dental professionals. PMID:23569933

  8. Staphylococcus aureus adherence to Candida albicans hyphae is mediated by the hyphal adhesin Als3p

    PubMed Central

    Peters, Brian M.; Ovchinnikova, Ekaterina S.; Krom, Bastiaan P.; Schlecht, Lisa Marie; Zhou, Han; Hoyer, Lois L.; Busscher, Henk J.; van der Mei, Henny C.; Jabra-Rizk, Mary Ann

    2012-01-01

    The bacterium Staphylococcus (St.) aureus and the opportunistic fungus Candida albicans are currently among the leading nosocomial pathogens, often co-infecting critically ill patients, with high morbidity and mortality. Previous investigations have demonstrated preferential adherence of St. aureus to C. albicans hyphae during mixed biofilm growth. In this study, we aimed to characterize the mechanism behind this observed interaction. C. albicans adhesin-deficient mutant strains were screened by microscopy to identify the specific receptor on C. albicans hyphae recognized by St. aureus. Furthermore, an immunoassay was developed to validate and quantify staphylococcal binding to fungal biofilms. The findings from these experiments implicated the C. albicans adhesin agglutinin-like sequence 3 (Als3p) in playing a major role in the adherence process. This association was quantitatively established using atomic force microscopy, in which the adhesion force between single cells of the two species was significantly reduced for a C. albicans mutant strain lacking als3. Confocal microscopy further confirmed these observations, as St. aureus overlaid with a purified recombinant Als3 N-terminal domain fragment (rAls3p) exhibited robust binding. Importantly, a strain of Saccharomyces cerevisiae heterologously expressing Als3p was utilized to further confirm this adhesin as a receptor for St. aureus. Although the parental strain does not bind bacteria, expression of Als3p on the cell surface conferred upon the yeast the ability to strongly bind St. aureus. To elucidate the implications of these in vitro findings in a clinically relevant setting, an ex vivo murine model of co-infection was designed using murine tongue explants. Fluorescent microscopic images revealed extensive hyphal penetration of the epithelium typical of C. albicans mucosal infection. Interestingly, St. aureus bacterial cells were only seen within the epithelial tissue when associated with the invasive

  9. Neutrophil-mediated protection of cultured human vascular endothelial cells from damage by growing Candida albicans hyphae

    SciTech Connect

    Edwards, J.E. Jr.; Rotrosen, D.; Fontaine, J.W.; Haudenschild, C.C.; Diamond, R.D.

    1987-05-01

    Interactions were studied between human neutrophils and cultured human umbilical vein endothelial cells invaded by Candida albicans. In the absence of neutrophils, progressive Candida germination and hyphal growth extensively damaged endothelial cell monolayers over a period of 4 to 6 hours, as determined both by morphological changes and release of /sup 51/Cr from radiolabeled endothelial cells. Monolayers were completely destroyed and replaced by hyphae after 18 hours of incubation. In contrast, when added 2 hours after the monolayers had been infected with Candida, neutrophils selectively migrated toward and attached to hyphae at points of hyphal penetration into individual endothelial cells (observed by time-lapse video-microscopy). Attached neutrophils spread over hyphal surfaces both within and beneath the endothelial cells; neutrophil recruitment to initial sites of leukocyte-Candida-endothelial cell interactions continued throughout the first 60 minutes of observation. Neutrophil spreading and stasis were observed only along Candida hyphae and at sites of Candida-endothelial cell interactions. These events resulted in 58.0% killing of Candida at 2 hours and subsequent clearance of Candida from endothelial cell monolayers, as determined by microcolony counts and morphological observation. On introduction of additional neutrophils to yield higher ratios of neutrophils to endothelial cells (10 neutrophils:1 endothelial cell), neutrophil migration toward hyphal elements continued. Despite retraction or displacement of occasional endothelial cells by invading Candida and neutrophils, most endothelial cells remained intact, viable, and motile as verified both by morphological observations and measurement of /sup 51/Cr release from radiolabeled monolayers.

  10. Investigation of minor species Candida africana, Candida stellatoidea and Candida dubliniensis in the Candida albicans complex among Yaoundé (Cameroon) HIV-infected patients.

    PubMed

    Ngouana, Thierry K; Krasteva, Donika; Drakulovski, Pascal; Toghueo, Rufin K; Kouanfack, Charles; Ambe, Akaba; Reynes, Jacques; Delaporte, Eric; Boyom, Fabrice F; Mallié, Michèle; Bertout, Sébastien

    2015-01-01

    Minor species of the Candida albicans complex may cause overestimation of the epidemiology of C. albicans, and misidentifications could mask their implication in human pathology. Authors determined the occurrence of minor species of the C. albicans complex (C. africana, C. dubliniensis and C. stellatoidea) among Yaoundé HIV-infected patients, Cameroon. Stool, vaginal discharge, urine and oropharyngeal samples were analysed by mycological diagnosis. Isolates were identified by conventional methods and mass spectrometry (MS; carried out by the matrix-assisted laser desorption-ionisation time-of-flight MS protocol). Candida albicans isolates were thereafter submitted to the PCR amplification of the Hwp1 gene. The susceptibility of isolates to antifungal drugs was tested using the Clinical and Laboratory Standards Institute M27-A3 protocol. From 115 C. albicans obtained isolates, neither C. dubliniensis nor C. stellatoidea was observed; two strains of C. africana (422PV and 448PV) were identified by PCR electrophoretic profiles at 700 bp. These two C. africana strains were vaginal isolates. The isolate 448PV was resistant to ketoconazole at the minimal inhibitory concentration of 2 μg ml(-1), and showed reduced susceptibility to amphotericin B at 1 μg ml(-1). This first report on C. africana occurrence in Cameroon brings clues for the understanding of the global epidemiology of this yeast as well as that of minor species of the C. albicans complex.

  11. Manipulation of host diet to reduce gastrointestinal colonization by the opportunistic pathogen Candida albicans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Candida albicans, the most common human fungal pathogen, can cause systemic infections with a mortality rate of ~40%. Infections arise from colonization of the gastrointestinal (GI) tract, where C. albicans is part of the normal microflora. Reducing colonization in at-risk patients using antifungal ...

  12. [Meningitis to Candida albicans at the adult, use of the new diagnosis methods].

    PubMed

    Duclos, G; Dumont, J-C; Ranque, S; Zieleskiewicz, L; Bruder, N

    2014-01-01

    Candida albicans or non-albicans are a frequent source of infection but seldom displayed in cerebrospinal fluid although responsible of an important number of nosocomial meningitis. Diagnosis is difficult which often delays treatment, which in turn hinders prognostic. This clinical case shows a patient afflicted with a deadly C. albicans meningitis and allows us to focus on new diagnostic tools and advice against this infection. PMID:25127852

  13. Biotin Auxotrophy and Biotin Enhanced Germ Tube Formation in Candida albicans

    PubMed Central

    Ahmad Hussin, Nur; Pathirana, Ruvini U.; Hasim, Sahar; Tati, Swetha; Scheib-Owens, Jessica A.; Nickerson, Kenneth W.

    2016-01-01

    Due to the increased number of immunocompromised patients, infections with the pathogen Candida albicans have significantly increased in recent years. C. albicans transition from yeast to germ tubes is one of the essential factors for virulence. In this study we noted that Lee’s medium, commonly used to induce filamentation, contained 500-fold more biotin than needed for growth and 40-fold more biotin than is typically added to growth media. Thus, we investigated the effects of excess biotin on growth rate and filamentation by C. albicans in different media. At 37 °C, excess biotin (4 µM) enhanced germ tube formation (GTF) ca. 10-fold in both Lee’s medium and a defined glucose-proline medium, and ca. 4-fold in 1% serum. Two biotin precursors, desthiobiotin and 7-keto-8-aminopelargonic acid (KAPA), also stimulated GTF. During these studies we also noted an inverse correlation between the number of times the inoculum had been washed and the concentration of serum needed to stimulate GTF. C. albicans cells that had been washed eight times achieved 80% GTF with only 0.1% sheep serum. The mechanism by which 1–4 µM biotin enhances GTF is still unknown except to note that equivalent levels of biotin are needed to create an internal supply of stored biotin and biotinylated histones. Biotin did not restore filamentation for any of the four known filamentation defective mutants tested. C. albicans is auxotrophic for biotin and this biotin auxotrophy was fulfilled by biotin, desthiobiotin, or KAPA. However, biotin auxotrophy is not temperature dependent or influenced by the presence of 5% CO2. Biotin starvation upregulated the biotin biosynthetic genes BIO2, BIO3, and BIO4 by 11-, 1500-, and 150-fold, respectively, and BIO2p is predicted to be mitochondrion-localized. Based on our findings, we suggest that biotin has two roles in the physiology of C. albicans, one as an enzymatic cofactor and another as a morphological regulator. Finally, we found no evidence

  14. Biotin Auxotrophy and Biotin Enhanced Germ Tube Formation in Candida albicans.

    PubMed

    Ahmad Hussin, Nur; Pathirana, Ruvini U; Hasim, Sahar; Tati, Swetha; Scheib-Owens, Jessica A; Nickerson, Kenneth W

    2016-01-01

    Due to the increased number of immunocompromised patients, infections with the pathogen Candida albicans have significantly increased in recent years. C. albicans transition from yeast to germ tubes is one of the essential factors for virulence. In this study we noted that Lee's medium, commonly used to induce filamentation, contained 500-fold more biotin than needed for growth and 40-fold more biotin than is typically added to growth media. Thus, we investigated the effects of excess biotin on growth rate and filamentation by C. albicans in different media. At 37 °C, excess biotin (4 µM) enhanced germ tube formation (GTF) ca. 10-fold in both Lee's medium and a defined glucose-proline medium, and ca. 4-fold in 1% serum. Two biotin precursors, desthiobiotin and 7-keto-8-aminopelargonic acid (KAPA), also stimulated GTF. During these studies we also noted an inverse correlation between the number of times the inoculum had been washed and the concentration of serum needed to stimulate GTF. C. albicans cells that had been washed eight times achieved 80% GTF with only 0.1% sheep serum. The mechanism by which 1-4 µM biotin enhances GTF is still unknown except to note that equivalent levels of biotin are needed to create an internal supply of stored biotin and biotinylated histones. Biotin did not restore filamentation for any of the four known filamentation defective mutants tested. C. albicans is auxotrophic for biotin and this biotin auxotrophy was fulfilled by biotin, desthiobiotin, or KAPA. However, biotin auxotrophy is not temperature dependent or influenced by the presence of 5% CO₂. Biotin starvation upregulated the biotin biosynthetic genes BIO2, BIO3, and BIO4 by 11-, 1500-, and 150-fold, respectively, and BIO2p is predicted to be mitochondrion-localized. Based on our findings, we suggest that biotin has two roles in the physiology of C. albicans, one as an enzymatic cofactor and another as a morphological regulator. Finally, we found no evidence supporting

  15. Biotin Auxotrophy and Biotin Enhanced Germ Tube Formation in Candida albicans

    PubMed Central

    Ahmad Hussin, Nur; Pathirana, Ruvini U.; Hasim, Sahar; Tati, Swetha; Scheib-Owens, Jessica A.; Nickerson, Kenneth W.

    2016-01-01

    Due to the increased number of immunocompromised patients, infections with the pathogen Candida albicans have significantly increased in recent years. C. albicans transition from yeast to germ tubes is one of the essential factors for virulence. In this study we noted that Lee’s medium, commonly used to induce filamentation, contained 500-fold more biotin than needed for growth and 40-fold more biotin than is typically added to growth media. Thus, we investigated the effects of excess biotin on growth rate and filamentation by C. albicans in different media. At 37 °C, excess biotin (4 µM) enhanced germ tube formation (GTF) ca. 10-fold in both Lee’s medium and a defined glucose-proline medium, and ca. 4-fold in 1% serum. Two biotin precursors, desthiobiotin and 7-keto-8-aminopelargonic acid (KAPA), also stimulated GTF. During these studies we also noted an inverse correlation between the number of times the inoculum had been washed and the concentration of serum needed to stimulate GTF. C. albicans cells that had been washed eight times achieved 80% GTF with only 0.1% sheep serum. The mechanism by which 1–4 µM biotin enhances GTF is still unknown except to note that equivalent levels of biotin are needed to create an internal supply of stored biotin and biotinylated histones. Biotin did not restore filamentation for any of the four known filamentation defective mutants tested. C. albicans is auxotrophic for biotin and this biotin auxotrophy was fulfilled by biotin, desthiobiotin, or KAPA. However, biotin auxotrophy is not temperature dependent or influenced by the presence of 5% CO2. Biotin starvation upregulated the biotin biosynthetic genes BIO2, BIO3, and BIO4 by 11-, 1500-, and 150-fold, respectively, and BIO2p is predicted to be mitochondrion-localized. Based on our findings, we suggest that biotin has two roles in the physiology of C. albicans, one as an enzymatic cofactor and another as a morphological regulator. Finally, we found no evidence

  16. Function and Regulation of Cph2 in Candida albicans

    PubMed Central

    Lane, Shelley; Di Lena, Pietro; Tormanen, Kati; Baldi, Pierre

    2015-01-01

    Candida albicans is associated with humans as both a harmless commensal organism and a pathogen. Cph2 is a transcription factor whose DNA binding domain is similar to that of mammalian sterol response element binding proteins (SREBPs). SREBPs are master regulators of cellular cholesterol levels and are highly conserved from fungi to mammals. However, ergosterol biosynthesis is regulated by the zinc finger transcription factor Upc2 in C. albicans and several other yeasts. Cph2 is not necessary for ergosterol biosynthesis but is important for colonization in the murine gastrointestinal (GI) tract. Here we demonstrate that Cph2 is a membrane-associated transcription factor that is processed to release the N-terminal DNA binding domain like SREBPs, but its cleavage is not regulated by cellular levels of ergosterol or oxygen. Chromatin immunoprecipitation sequencing (ChIP-seq) shows that Cph2 binds to the promoters of HMS1 and other components of the regulatory circuit for GI tract colonization. In addition, 50% of Cph2 targets are also bound by Hms1 and other factors of the regulatory circuit. Several common targets function at the head of the glycolysis pathway. Thus, Cph2 is an integral part of the regulatory circuit for GI colonization that regulates glycolytic flux. Transcriptome sequencing (RNA-seq) shows a significant overlap in genes differentially regulated by Cph2 and hypoxia, and Cph2 is important for optimal expression of some hypoxia-responsive genes in glycolysis and the citric acid cycle. We suggest that Cph2 and Upc2 regulate hypoxia-responsive expression in different pathways, consistent with a synthetic lethal defect of the cph2 upc2 double mutant in hypoxia. PMID:26342020

  17. Humoral Immunity Links Candida albicans Infection and Celiac Disease

    PubMed Central

    Fradin, Chantal; Salleron, Julia; Damiens, Sébastien; Moragues, Maria Dolores; Souplet, Vianney; Jouault, Thierry; Robert, Raymond; Dubucquoi, Sylvain; Sendid, Boualem; Colombel, Jean Fréderic; Poulain, Daniel

    2015-01-01

    Objective The protein Hwp1, expressed on the pathogenic phase of Candida albicans, presents sequence analogy with the gluten protein gliadin and is also a substrate for transglutaminase. This had led to the suggestion that C. albicans infection (CI) may be a triggering factor for Celiac disease (CeD) onset. We investigated cross-immune reactivity between CeD and CI. Methods Serum IgG levels against recombinant Hwp1 and serological markers of CeD were measured in 87 CeD patients, 41 CI patients, and 98 healthy controls (HC). IgA and IgG were also measured in 20 individuals from each of these groups using microchips sensitized with 38 peptides designed from the N-terminal of Hwp1. Results CI and CeD patients had higher levels of anti-Hwp1 (p=0.0005 and p=0.004) and anti-gliadin (p=0.002 and p=0.0009) antibodies than HC but there was no significant difference between CeD and CI patients. CeD and CI patients had higher levels of anti-transglutaminase IgA than HC (p=0.0001 and p=0.0039). During CI, the increase in anti-Hwp1 paralleled the increase in anti-gliadin antibodies. Microchip analysis showed that CeD patients were more reactive against some Hwp1 peptides than CI patients, and that some deamidated peptides were more reactive than their native analogs. Binding of IgG from CeD patients to Hwp1 peptides was inhibited by γIII gliadin peptides. Conclusions Humoral cross-reactivity between Hwp1 and gliadin was observed during CeD and CI. Increased reactivity to Hwp1 deamidated peptide suggests that transglutaminase is involved in this interplay. These results support the hypothesis that CI may trigger CeD onset in genetically-susceptible individuals. PMID:25793717

  18. Functional characterization of Candida albicans Hos2 histone deacetylase

    PubMed Central

    Karthikeyan, G; Paul-Satyaseela, Maneesh; Dhatchana Moorthy, Nachiappan; Gopalaswamy, Radha; Narayanan, Shridhar

    2014-01-01

    Candida albicans is a mucosal commensal organism capable of causing superficial (oral and vaginal thrush) infections in immune normal hosts, but is a major pathogen causing systemic and mucosal infections in immunocompromised individuals. Azoles have been very effective anti-fungal agents and the mainstay in treating opportunistic mold and yeast infections. Azole resistant strains have emerged compromising the utility of this class of drugs. It has been shown that azole resistance can be reversed by the co-administration of a histone deacetylase (HDAC) inhibitor, suggesting that resistance is mediated by epigenetic mechanisms possibly involving Hos2, a fungal deacetylase. We report here the cloning and functional characterization of  HOS2 (High Osmolarity  Sensitive) , a gene coding for fungal histone deacetylase from  C. albicans. Inhibition studies showed that Hos2 is susceptible to pan inhibitors such as trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), but is not inhibited by class I inhibitors such as MS-275. This  in  vitro enzymatic assay, which is amenable to high throughput could be used for screening potent fungal Hos2 inhibitors that could be a potential anti-fungal adjuvant. Purified Hos2 protein consistently deacetylated tubulins, rather than histones from TSA-treated cells. Hos2 has been reported to be a putative NAD+ dependent histone deacetylase, a feature of sirtuins. We assayed for sirtuin activation with resveratrol and purified Hos2 protein and did not find any sirtuin activity. PMID:25110576

  19. Sampling of Candida albicans and Candida tropicalis by Langerin-positive dendritic cells in mouse Peyer's patches.

    PubMed

    De Jesus, Magdia; Rodriguez, Adam E; Yagita, Hideo; Ostroff, Gary R; Mantis, Nicholas J

    2015-11-01

    Members of the Candida genus, including C. albicans and C. tropicalis are opportunistic fungal pathogens that are increasingly associated with gastrointestinal infections and inflammatory bowel diseases. In healthy populations, however, C. albicans and C. tropicalis are considered benign members of the mycobiome, and are presumably kept in check by the mucosal immune system. In this study, we demonstrate in mice that C. albicans and C. tropicalis are sampled by Peyer's patch (PP) dendritic cells (DCs). Uptake into gut-associated lymphoid tissues occurred rapidly and was at least partly M cell-dependent. C. albicans and C. tropicalis preferentially localized in (and persisted within) a recently identified sub- population of Peyer's patch DCs distinguished by their expression of the C-type lectin receptor, Langerin. This study is the first to identify a subset of PP DCs capable of sampling Candida species.

  20. Ribosomal protein S6 phosphorylation is controlled by TOR and modulated by PKA in Candida albicans.

    PubMed

    Chowdhury, Tahmeena; Köhler, Julia R

    2015-10-01

    TOR and PKA signaling pathways control eukaryotic cell growth and proliferation. TOR activity in model fungi, such as Saccharomyces cerevisiae, responds principally to nutrients, e.g., nitrogen and phosphate sources, which are incorporated into the growing cell mass; PKA signaling responds to the availability of the cells' major energy source, glucose. In the fungal commensal and pathogen, Candida albicans, little is known of how these pathways interact. Here, the signal from phosphorylated ribosomal protein S6 (P-S6) was defined as a surrogate marker for TOR-dependent anabolic activity in C. albicans. Nutritional, pharmacologic and genetic modulation of TOR activity elicited corresponding changes in P-S6 levels. The P-S6 signal corresponded to translational activity of a GFP reporter protein. Contributions of four PKA pathway components to anabolic activation were then examined. In high glucose concentrations, only Tpk2 was required to upregulate P-S6 to physiologic levels, whereas all four tested components were required to downregulate P-S6 in low glucose. TOR was epistatic to PKA components with respect to P-S6. In many host niches inhabited by C. albicans, glucose is scarce, with protein being available as a nitrogen source. We speculate that PKA may modulate TOR-dependent cell growth to a rate sustainable by available energy sources, when monomers of anabolic processes, such as amino acids, are abundant.

  1. Terpenoids of plant origin inhibit morphogenesis, adhesion, and biofilm formation by Candida albicans.

    PubMed

    Raut, Jayant S; Shinde, Ravikumar B; Chauhan, Nitin M; Karuppayil, S Mohan

    2013-01-01

    Biofilm-related infections caused by Candida albicans and associated drug resistant micro-organisms are serious problems for immunocompromised populations. Molecules which can prevent or remove biofilms are needed. Twenty-eight terpenoids of plant origin were analysed for their activity against growth, virulence attributes, and biofilms of C. albicans. Eighteen molecules exhibited minimum inhibitory concentrations of <2 mg ml(-1) for planktonic growth. Selected molecules inhibited yeast to hyphal dimorphism at low concentrations (0.031-0.5 mg ml(-1)), while adhesion to a solid surface was prevented at 0.5-2 mg ml(-1). Treatment with 14 terpenoids resulted in significant (p < 0.05) inhibition of biofilm formation, and of these, linalool, nerol, isopulegol, menthol, carvone, α-thujone, and farnesol exhibited biofilm-specific activity. Eight terpenoids were identified as inhibitors of mature biofilms. This study demonstrated the antibiofilm potential of terpenoids, which need to be further explored as therapeutic strategy against biofilm associated infections of C. albicans. PMID:23216018

  2. Compositional and immunobiological analyses of extracellular vesicles released by Candida albicans.

    PubMed

    Vargas, Gabriele; Rocha, Juliana D B; Oliveira, Debora Leite; Albuquerque, Priscila Costa; Frases, Susana; Santos, Suelen S; Nosanchuk, Joshua Daniel; Gomes, Andre Marco Oliveira; Medeiros, Lia C A S; Miranda, Kildare; Sobreira, Tiago J P; Nakayasu, Ernesto S; Arigi, Emma A; Casadevall, Arturo; Guimaraes, Allan J; Rodrigues, Marcio L; Freire-de-Lima, Celio Geraldo; Almeida, Igor C; Nimrichter, Leonardo

    2015-03-01

    The release of extracellular vesicles (EV) by fungal organisms is considered an alternative transport mechanism to trans-cell wall passage of macromolecules. Previous studies have revealed the presence of EV in culture supernatants from fungal pathogens, such as Cryptococcus neoformans, Histoplasma capsulatum, Paracoccidioides brasiliensis, Sporothrix schenckii, Malassezia sympodialis and Candida albicans. Here we investigated the size, composition, kinetics of internalization by bone marrow-derived murine macrophages (MO) and dendritic cells (DC), and the immunomodulatory activity of C. albicans EV. We also evaluated the impact of EV on fungal virulence using the Galleria mellonella larvae model. By transmission electron microscopy and dynamic light scattering, we identified two populations ranging from 50 to 100 nm and 350 to 850 nm. Two predominant seroreactive proteins (27 kDa and 37 kDa) and a group of polydispersed mannoproteins were observed in EV by immunoblotting analysis. Proteomic analysis of C. albicans EV revealed proteins related to pathogenesis, cell organization, carbohydrate and lipid metabolism, response to stress, and several other functions. The major lipids detected by thin-layer chromatography were ergosterol, lanosterol and glucosylceramide. Short exposure of MO to EV resulted in internalization of these vesicles and production of nitric oxide, interleukin (IL)-12, transforming growth factor-beta (TGF-β) and IL-10. Similarly, EV-treated DC produced IL-12p40, IL-10 and tumour necrosis factor-alpha. In addition, EV treatment induced the up-regulation of CD86 and major histocompatibility complex class-II (MHC-II). Inoculation of G. mellonella larvae with EV followed by challenge with C. albicans reduced the number of recovered viable yeasts in comparison with infected larvae control. Taken together, our results demonstrate that C. albicans EV were immunologically active and could potentially interfere with the host responses in the setting of

  3. Apoptosis induced by environmental stresses and amphotericin B in Candida albicans.

    PubMed

    Phillips, Andrew J; Sudbery, Ian; Ramsdale, Mark

    2003-11-25

    New antifungal agents are urgently required to combat life-threatening infections caused by opportunistic fungal pathogens like Candida albicans. The manipulation of endogenous fungal programmed cell death responses could provide a basis for future therapies. Here we assess the physiology of death in C. albicans in response to environmental stresses (acetic acid and hydrogen peroxide) and an antifungal agent (amphotericin B). Exposure of C. albicans to 40-60 mM acetic acid, 5-10 mM hydrogen peroxide, or 4-8 microg.ml-1 amphotericin B produced cellular changes reminiscent of mammalian apoptosis. Nonviable cells that excluded propidium iodide displayed the apoptotic marker phosphatidylserine (as shown by annexin-V-FITC labeling), were terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL)-positive (indicating nuclease-mediated double-strand DNA breakage), and produced reactive oxygen species. Ultrastructural changes in apoptotic cells included chromatin condensation and margination, separation of the nuclear envelope, and nuclear fragmentation. C. albicans cells treated at higher doses of these compounds showed cellular changes characteristic of necrosis. Necrotic cells displayed reduced TUNEL staining, a lack of surface phosphatidylserine, limited reactive oxygen species production, and an inability to exclude propidium iodide. Necrotic cells lacked defined nuclei and showed extensive intracellular vacuolization. Apoptosis in C. albicans was associated with an accumulation of cells in the G2/M phase of the cell cycle, and under some apoptosis-inducing conditions, significant proportions of yeast cells switched to hyphal growth before dying. This is a demonstration of apoptosis in a medically important fungal pathogen. PMID:14623979

  4. Quercetin sensitizes fluconazole-resistant candida albicans to induce apoptotic cell death by modulating quorum sensing.

    PubMed

    Singh, B N; Upreti, D K; Singh, B R; Pandey, G; Verma, S; Roy, S; Naqvi, A H; Rawat, A K S

    2015-04-01

    Quorum sensing (QS) regulates group behaviors of Candida albicans such as biofilm, hyphal growth, and virulence factors. The sesquiterpene alcohol farnesol, a QS molecule produced by C. albicans, is known to regulate the expression of virulence weapons of this fungus. Fluconazole (FCZ) is a broad-spectrum antifungal drug that is used for the treatment of C. albicans infections. While FCZ can be cytotoxic at high concentrations, our results show that at much lower concentrations, quercetin (QC), a dietary flavonoid isolated from an edible lichen (Usnea longissima), can be implemented as a sensitizing agent for FCZ-resistant C. albicans NBC099, enhancing the efficacy of FCZ. QC enhanced FCZ-mediated cell killing of NBC099 and also induced cell death. These experiments indicated that the combined application of both drugs was FCZ dose dependent rather than QC dose dependent. In addition, we found that QC strongly suppressed the production of virulence weapons-biofilm formation, hyphal development, phospholipase, proteinase, esterase, and hemolytic activity. Treatment with QC also increased FCZ-mediated cell death in NBC099 biofilms. Interestingly, we also found that QC enhances the anticandidal activity of FCZ by inducing apoptotic cell death. We have also established that this sensitization is reliant on the farnesol response generated by QC. Molecular docking studies also support this conclusion and suggest that QC can form hydrogen bonds with Gln969, Thr1105, Ser1108, Arg1109, Asn1110, and Gly1061 in the ATP binding pocket of adenylate cyclase. Thus, this QS-mediated combined sensitizer (QC)-anticandidal agent (FCZ) strategy may be a novel way to enhance the efficacy of FCZ-based therapy of C. albicans infections. PMID:25645848

  5. Candida albicans suppresses nitric oxide generation from macrophages via a secreted molecule.

    PubMed

    Collette, John R; Zhou, Huaijin; Lorenz, Michael C

    2014-01-01

    Macrophages and neutrophils generate a potent burst of reactive oxygen and nitrogen species as a key aspect of the antimicrobial response. While most successful pathogens, including the fungus Candida albicans, encode enzymes for the detoxification of these compounds and repair of the resulting cellular damage, some species actively modulate immune function to suppress the generation of these toxic compounds. We report here that C. albicans actively inhibits macrophage production of nitric oxide (NO). NO production was blocked in a dose-dependent manner when live C. albicans were incubated with either cultured or bone marrow-derived mouse macrophages. While filamentous growth is a key virulence trait, yeast-locked fungal cells were still capable of dose-dependent NO suppression. C. albicans suppresses NO production from macrophages stimulated by exposure to IFN-γ and LPS or cells of the non-pathogenic Saccharomyces cerevisiae. The NO inhibitory activity was produced only when the fungal cells were in direct contact with macrophages, but the compound itself was secreted into the culture media. LPS/IFNγ stimulated macrophages cultured in cell-free conditioned media from co-cultures showed reduced levels of iNOS enzymatic activity and lower amounts of iNOS protein. Initial biochemical characterization of this activity indicates that the inhibitor is a small, aqueous, heat-stable compound. In summary, C. albicans actively blocks NO production by macrophages via a secreted mediator; these findings expand our understanding of phagocyte modulation by this important fungal pathogen and represent a potential target for intervention to enhance antifungal immune responses.

  6. Integration of Posttranscriptional Gene Networks into Metabolic Adaptation and Biofilm Maturation in Candida albicans

    PubMed Central

    Harrison, Paul F.; Lo, Tricia L.; Quenault, Tara; Dagley, Michael J.; Bellousoff, Matthew; Powell, David R.; Beilharz, Traude H.; Traven, Ana

    2015-01-01

    The yeast Candida albicans is a human commensal and opportunistic pathogen. Although both commensalism and pathogenesis depend on metabolic adaptation, the regulatory pathways that mediate metabolic processes in C. albicans are incompletely defined. For example, metabolic change is a major feature that distinguishes community growth of C. albicans in biofilms compared to suspension cultures, but how metabolic adaptation is functionally interfaced with the structural and gene regulatory changes that drive biofilm maturation remains to be fully understood. We show here that the RNA binding protein Puf3 regulates a posttranscriptional mRNA network in C. albicans that impacts on mitochondrial biogenesis, and provide the first functional data suggesting evolutionary rewiring of posttranscriptional gene regulation between the model yeast Saccharomyces cerevisiae and C. albicans. A proportion of the Puf3 mRNA network is differentially expressed in biofilms, and by using a mutant in the mRNA deadenylase CCR4 (the enzyme recruited to mRNAs by Puf3 to control transcript stability) we show that posttranscriptional regulation is important for mitochondrial regulation in biofilms. Inactivation of CCR4 or dis-regulation of mitochondrial activity led to altered biofilm structure and over-production of extracellular matrix material. The extracellular matrix is critical for antifungal resistance and immune evasion, and yet of all biofilm maturation pathways extracellular matrix biogenesis is the least understood. We propose a model in which the hypoxic biofilm environment is sensed by regulators such as Ccr4 to orchestrate metabolic adaptation, as well as the regulation of extracellular matrix production by impacting on the expression of matrix-related cell wall genes. Therefore metabolic changes in biofilms might be intimately linked to a key biofilm maturation mechanism that ultimately results in untreatable fungal disease. PMID:26474309

  7. Characteristics of Candida albicans Biofilms Grown in a Synthetic Urine Medium▿

    PubMed Central

    Uppuluri, Priya; Dinakaran, Hemamalini; Thomas, Derek P.; Chaturvedi, Ashok K.; Lopez-Ribot, Jose L.

    2009-01-01

    Urinary tract infections (UTIs) are the most common type of nosocomial infection, and Candida albicans is the most frequent organism causing fungal UTIs. Presence of an indwelling urinary catheter represents a significant risk factor for UTIs. Furthermore, these infections are frequently associated with the formation of biofilms on the surface of these catheters. Here, we describe the characterization of C. albicans biofilms formed in vitro using synthetic urine (SU) medium and the frequently used RPMI medium and compare the results. Biofilms of C. albicans strain SC5314 were formed in 96-well microtiter plates and on silicon elastomer pieces using both SU and RPMI media. Biofilm formation was monitored by microscopy and a colorimetric XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction assay. As in biofilms grown in RPMI medium, time course studies revealed that biofilm formation using SU medium occurred after an initial adherence phase, followed by growth, proliferation, and maturation. However, microscopy techniques revealed that the architectural complexity of biofilms formed in SU medium was lower than that observed for those formed using RPMI medium. In particular, the level of filamentation of cells within the biofilms formed in SU medium was diminished compared to those in the biofilms grown in RPMI medium. This observation was also corroborated by expression profiling of five filamentation-associated genes using quantitative real-time reverse transcriptase PCR. Sessile C. albicans cells were resistant to fluconazole and amphotericin B, irrespective of the medium used to form the biofilms. However, caspofungin exhibited potent in vitro activity at therapeutic levels against C. albicans biofilms grown in both SU and RPMI media. PMID:19794044

  8. Characteristics of Candida albicans biofilms grown in a synthetic urine medium.

    PubMed

    Uppuluri, Priya; Dinakaran, Hemamalini; Thomas, Derek P; Chaturvedi, Ashok K; Lopez-Ribot, Jose L

    2009-12-01

    Urinary tract infections (UTIs) are the most common type of nosocomial infection, and Candida albicans is the most frequent organism causing fungal UTIs. Presence of an indwelling urinary catheter represents a significant risk factor for UTIs. Furthermore, these infections are frequently associated with the formation of biofilms on the surface of these catheters. Here, we describe the characterization of C. albicans biofilms formed in vitro using synthetic urine (SU) medium and the frequently used RPMI medium and compare the results. Biofilms of C. albicans strain SC5314 were formed in 96-well microtiter plates and on silicon elastomer pieces using both SU and RPMI media. Biofilm formation was monitored by microscopy and a colorimetric XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction assay. As in biofilms grown in RPMI medium, time course studies revealed that biofilm formation using SU medium occurred after an initial adherence phase, followed by growth, proliferation, and maturation. However, microscopy techniques revealed that the architectural complexity of biofilms formed in SU medium was lower than that observed for those formed using RPMI medium. In particular, the level of filamentation of cells within the biofilms formed in SU medium was diminished compared to those in the biofilms grown in RPMI medium. This observation was also corroborated by expression profiling of five filamentation-associated genes using quantitative real-time reverse transcriptase PCR. Sessile C. albicans cells were resistant to fluconazole and amphotericin B, irrespective of the medium used to form the biofilms. However, caspofungin exhibited potent in vitro activity at therapeutic levels against C. albicans biofilms grown in both SU and RPMI media.

  9. Lipopeptides from Bacillus subtilis AC7 inhibit adhesion and biofilm formation of Candida albicans on silicone.

    PubMed

    Ceresa, Chiara; Rinaldi, Maurizio; Chiono, Valeria; Carmagnola, Irene; Allegrone, Gianna; Fracchia, Letizia

    2016-10-01

    Candida albicans is the major fungus that colonises medical implants, causing device-associated infections with high mortality. Antagonistic bacterial products with interesting biological properties, such as biosurfactants, have recently been considered for biofilm prevention. This study investigated the activity of lipopeptide biosurfactant produced by Bacillus subtilis AC7 (AC7 BS) against adhesion and biofilm formation of C. albicans on medical-grade silicone elastomeric disks (SEDs). Chemical analysis, stability, surface activities of AC7 BS crude extract and physicochemical characterisation of the coated silicone disk surfaces were also carried out. AC7 BS showed a good reduction of water surface tension, low critical micelle concentration, good emulsification activity, thermal resistance and pH stability. Co-incubation with 2 mg ml(-1) AC7 BS significantly reduced adhesion and biofilm formation of three C. albicans strains on SEDs in a range of 67-69 % and of 56-57 %, respectively. On pre-coated SEDs, fungal adhesion and biofilm formation were reduced by 57-62 % and 46-47 %, respectively. Additionally, AC7 BS did not inhibit viability of C. albicans strains in both planktonic and sessile form. Chemical analysis of the crude extract revealed the presence of two families of lipopeptides, principally surfactin and a lower percentage of fengycin. The evaluation of surface wettability indicated that AC7 BS coating of SEDs surface was successful although uneven. AC7 BS significantly prohibits the initial deposition of C. albicans and slows biofilm growth, suggesting a potential role of biosurfactant coatings for preventing fungal infection associated with silicone medical devices. PMID:27444239

  10. Blocking of Candida albicans biofilm formation by cis-2-dodecenoic acid and trans-2-dodecenoic acid.

    PubMed

    Zhang, Yuqian; Cai, Chen; Yang, Yuxiang; Weng, Lixing; Wang, Lianhui

    2011-11-01

    Candida is an important opportunistic human fungal pathogen. Infections caused by Candida albicans are related to the formation of a biofilm. The biofilm enhances the resistance of the C. albicans defence system, increases its resistance to antifungal drugs and induces increased drug tolerance, making clinical care more challenging. The in vitro activity of cis-2-dodecenoic acid (BDSF; a diffusible signal factor from Burkholderia cenocepacia) and trans-2-dodecenoic acid (trans-BDSF) against C. albicans growth, germ-tube germination and biofilm formation was estimated by absorbance measurements and microscopic assessments. C. albicans biofilms were prepared using a static microtitre plate model. Quantitative analysis of biofilm formation was performed using a 2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide reduction assay to evaluate the effect of different concentrations of BDSF and trans-BDSF at different stages of biofilm formation. Reductions in biofilm structure and formation were visualized by inverted microscopy. Real-time RT-PCR was employed to estimate the mRNA expression levels of the hyphae-specific genes HWP1 and ALS3. It was found that 30 µM of either BDSF or trans-BDSF reduced germ-tube formation by approximately 70 % without inhibiting yeast growth. Yeast growth was strongly repressed by the exogenous addition of 300 µM BDSF and trans-BDSF at 0 and 1 h after cell attachment, with biofilm formation being reduced by approximately 90 and 60 %, respectively. BDSF and trans-BDSF were more effective against biofilm formation than farnesol and the diffusible signal factor cis-11-methyl-2-dodecenoic acid. None of the four drugs was able to destroy pre-formed biofilms. Real-time RT-PCR analysis showed that HWP1 was downregulated by approximately 90 % and ALS3 was downregulated by 70-80 % by 60 µM BDSF and trans-BDSF, implying that BDSF and trans-BDSF block C. albicans biofilm formation by interfering with the morphological

  11. Identification and characterization of TUP1-regulated genes in Candida albicans.

    PubMed Central

    Braun, B R; Head, W S; Wang, M X; Johnson, A D

    2000-01-01

    TUP1 encodes a transcriptional repressor that negatively controls filamentous growth in Candida albicans. Using subtractive hybridization, we identified six genes, termed repressed by TUP1 (RBT), whose expression is regulated by TUP1. One of the genes (HWP1) has previously been characterized, and a seventh TUP1-repressed gene (WAP1) was recovered due to its high similarity to RBT5. These genes all encode secreted or cell surface proteins, and four out of the seven (HWP1, RBT1, RBT5, and WAP1) encode putatively GPI-modified cell wall proteins. The remaining three, RBT2, RBT4, and RBT7, encode, respectively, an apparent ferric reductase, a plant pathogenesis-related protein (PR-1), and a putative secreted RNase T2. The expression of RBT1, RBT4, RBT5, HWP1, and WAP1 was induced in wild-type cells during the switch from the yeast form to filamentous growth, indicating the importance of TUP1 in regulating this process and implicating the RBTs in hyphal-specific functions. We produced knockout strains in C. albicans for RBT1, RBT2, RBT4, RBT5, and WAP1 and detected no phenotypes on several laboratory media. However, two animal models for C. albicans infection, a rabbit cornea model and a mouse systemic infection model, revealed that rbt1Delta and rbt4Delta strains had significantly reduced virulence. TUP1 appears, therefore, to regulate many genes in C. albicans, a significant fraction of which are induced during filamentous growth, and some of which participate in pathogenesis. PMID:10978273

  12. Convergent Regulation of Candida albicans Aft2 and Czf1 in Invasive and Opaque Filamentation.

    PubMed

    Xu, Ning; Dong, Yi-Jie; Yu, Qi-Lin; Zhang, Bing; Zhang, Meng; Jia, Chang; Chen, Yu-Lu; Zhang, Biao; Xing, Lai-Jun; Li, Ming-Chun

    2015-09-01

    Candida albicans is the most common fungal pathogen of mucosal infections and invasive diseases in immuno-compromised humans. The abilities of yeast-hyphal growth and white-opaque switching affect C. albicans physiology and virulence. Here, we showed that C. albicans Aft2 regulator was required for embedded filamentous growth and opaque cell-type formation. Under low-temperature matrix embedded conditions, Aft2 functioned downstream of Czf1-mediated pathway and was required for invasive filamentation. Moreover, deletion of AFT2 significantly reduced opaque cell-type formation under N-acetylglucosamine (GlcNAc) inducing conditions. Ectopic expression of CZF1 slightly increased the white-opaque switching frequency in the aft2Δ/Δ mutant, but did not completely restore to wild-type levels, suggesting that Czf1 at least partially bypassed the essential requirement for Aft2 in response to opaque-inducing cues. In addition, multiple environmental cues altered AFT2 mRNA and protein levels, such as low temperature, physical environment and GlcNAc. Although the absence of Czf1 or Efg1 also increased the expression level of AFT2 gene, deletion of CZF1 remarkably reduced the stability of Aft2 protein. Furthermore, C. albicans Aft2 physically interacted with Czf1 under all tested conditions, whereas the interaction between Aft2 and Efg1 was barely detectable under embedded conditions, supporting the hypothesis that Aft2, together with Czf1, contributed to activate filamentous growth by antagonizing Efg1-mediated repression under matrix-embedded conditions.

  13. Association of Oral Candida albicans with Severe Early Childhood Caries - A Pilot Study

    PubMed Central

    Thomas, Ann; Mhambrey, Sanjana; Chokshi, Achala; Jana, Sinjana; Thakur, Sneha; Jose, Deepak; Bajpai, Garima

    2016-01-01

    Introduction In early childhood, children are more susceptible to opportunistic microbial colonization in the oral cavity due to immature immune system and not fully established micro flora. The current literature proposes a probable role of Candida albicans, a fungus in the etiopathogenesis of dental caries. Aim This study was conducted to compare the Candida albicans count in children with severe early childhood caries and caries free children. Materials and Methods A cross-sectional study was conducted in 40 randomly selected healthy children between 12 to 71 months of age, who were divided into two groups based on the caries experience as Severe Early Childhood Caries (SECC) (dmfs ≥4) and caries free (dmfs = 0). The caries experiences (dmfs index) of the 40 children were recorded using visible light and diagnostic instruments. A 2ml sample of unstimulated whole saliva collected from the children was transported to the microbiology laboratory in universal containers and evaluated for Candida albicans count using the selective media. The data was statistically analyzed using SPSS software 17.0. Results Candida albicans was found in both the SECC group and caries free group. Median Candida albicans of the SECC group was numerically greater than the caries free group and this difference was highly statistically significant (p=0.012). Conclusion In this present cross-sectional study, we found a 100% prevalence of Candida albicans in the saliva of the study children. There was a highly significant increase in Candida albicans count in SECC children compared to the caries free children. PMID:27656551

  14. Effects of histatin 5 and derived peptides on Candida albicans.

    PubMed Central

    Ruissen, A L; Groenink, J; Helmerhorst, E J; Walgreen-Weterings, E; Van't Hof, W; Veerman, E C; Nieuw Amerongen, A V

    2001-01-01

    Three anti-microbial peptides were compared with respect to their killing activity against Candida albicans and their ability to disturb its cellular and internal membranes. Histatin 5 is an anti-fungal peptide occurring naturally in human saliva, while dhvar4 and dhvar5 are variants of its active domain, with increased anti-microbial activity. dhvar4 has increased amphipathicity compared with histatin 5, whereas dhvar5 has amphipathicity comparable with that of histatin 5. All three peptides caused depolarization of the cytoplasmic and/or mitochondrial membrane, indicating membranolytic activity. For the variant peptides both depolarization and killing occurred at a faster rate. With FITC-labelled peptides, no association with the cytoplasmic membrane was observed, contradicting the formation of permanent transmembrane multimeric peptide pores. Instead, the peptides were internalized and act on internal membranes, as demonstrated with mitochondrion- and vacuole-specific markers. In comparison with histatin 5, the variant peptides showed a more destructive effect on mitochondria. Entry of the peptides and subsequent killing were dependent on the metabolic state of the cells. Blocking of the mitochondrial activity led to complete protection against histatin 5 activity, whereas that of dhvar4 was hardly affected and that of dhvar5 was affected only intermediately. PMID:11368762

  15. Integrating Candida albicans metabolism with biofilm heterogeneity by transcriptome mapping

    PubMed Central

    Rajendran, Ranjith; May, Ali; Sherry, Leighann; Kean, Ryan; Williams, Craig; Jones, Brian L.; Burgess, Karl V.; Heringa, Jaap; Abeln, Sanne; Brandt, Bernd W.; Munro, Carol A.; Ramage, Gordon

    2016-01-01

    Candida albicans biofilm formation is an important virulence factor in the pathogenesis of disease, a characteristic which has been shown to be heterogeneous in clinical isolates. Using an unbiased computational approach we investigated the central metabolic pathways driving biofilm heterogeneity. Transcripts from high (HBF) and low (LBF) biofilm forming isolates were analysed by RNA sequencing, with 6312 genes identified to be expressed in these two phenotypes. With a dedicated computational approach we identified and validated a significantly differentially expressed subnetwork of genes associated with these biofilm phenotypes. Our analysis revealed amino acid metabolism, such as arginine, proline, aspartate and glutamate metabolism, were predominantly upregulated in the HBF phenotype. On the contrary, purine, starch and sucrose metabolism was generally upregulated in the LBF phenotype. The aspartate aminotransferase gene AAT1 was found to be a common member of these amino acid pathways and significantly upregulated in the HBF phenotype. Pharmacological inhibition of AAT1 enzyme activity significantly reduced biofilm formation in a dose-dependent manner. Collectively, these findings provide evidence that biofilm phenotype is associated with differential regulation of metabolic pathways. Understanding and targeting such pathways, such as amino acid metabolism, is potentially useful for developing diagnostics and new antifungals to treat biofilm-based infections. PMID:27765942

  16. Prosthetic joint infections with osteomyelitis due to Candida albicans.

    PubMed

    Lerch, K; Kalteis, T; Schubert, T; Lehn, N; Grifka, J

    2003-12-01

    We report the case of a 78-year-old woman who suffered from a severe soft tissue and bone infection of her left knee 3 years after a total knee-joint replacement without loosening of her endoprosthesis. Cultures from joint aspiration and tissue specimen identified Staphylococcus aureus and Candida albicans. Direct microscopic examination of vital spongy bone and fibrous tissue revealed microabscesses and seeds of yeasts inside the fatty marrow and interface. After removal of the prosthesis several soft tissue and bone specimens were taken during planned re-operations. The histological examination showed no morphological changing, no reduction or extinction of the yeast cells under fluconazole therapy with a dosage of 6 mg kg(-1) body weight (400 mg daily). Curing of the fungal infection with eradication of the yeasts in the bony specimens was achieved with higher doses of 12 mg kg(-1) body weight (800 mg day(-1)) over a 2 month regimen in combination with repeated surgical debridements.

  17. Molecular mechanisms of primary resistance to flucytosine in Candida albicans.

    PubMed

    Hope, William W; Tabernero, Lydia; Denning, David W; Anderson, Michael J

    2004-11-01

    Primary resistance in Candida albicans to flucytosine (5-FC) was investigated in 25 strains by identifying and sequencing the genes FCA1, FUR1, FCY21, and FCY22, which code for cytosine deaminase, uracil phosphoribosyltransferase (UPRT), and two purine-cytosine permeases, respectively. These proteins are involved in pyrimidine salvage and 5-FC metabolism. An association between a polymorphic nucleotide and resistance to 5-FC was found within FUR1 where the substitution of cytidylate for thymidylate at nucleotide position 301 results in the replacement of arginine with cysteine at amino acid position 101 in UPRT. Isolates that are homozygous for this mutation display increased levels of resistance to 5-FC, whereas heterozygous isolates have reduced susceptibility. Three-dimensional protein modeling of UPRT suggests that the Arg101Cys mutation disturbs the quaternary structure of the enzyme, which is postulated to compromise optimal enzyme activity. A single resistant isolate, lacking the above polymorphism in FUR1, has a homozygous polymorphism in FCA1 that results in a glycine-to-aspartate substitution at position 28 in cytosine deaminase.

  18. Molecular mechanisms of action of herbal antifungal alkaloid berberine, in Candida albicans.

    PubMed

    Dhamgaye, Sanjiveeni; Devaux, Frédéric; Vandeputte, Patrick; Khandelwal, Nitesh Kumar; Sanglard, Dominique; Mukhopadhyay, Gauranga; Prasad, Rajendra

    2014-01-01

    Candida albicans causes superficial to systemic infections in immuno-compromised individuals. The concomitant use of fungistatic drugs and the lack of cidal drugs frequently result in strains that could withstand commonly used antifungals, and display multidrug resistance (MDR). In search of novel fungicidals, in this study, we have explored a plant alkaloid berberine (BER) for its antifungal potential. For this, we screened an in-house transcription factor (TF) mutant library of C. albicans strains towards their susceptibility to BER. Our screen of TF mutant strains identified a heat shock factor (HSF1), which has a central role in thermal adaptation, to be most responsive to BER treatment. Interestingly, HSF1 mutant was not only highly susceptible to BER but also displayed collateral susceptibility towards drugs targeting cell wall (CW) and ergosterol biosynthesis. Notably, BER treatment alone could affect the CW integrity as was evident from the growth retardation of MAP kinase and calcineurin pathway null mutant strains and transmission electron microscopy. However, unlike BER, HSF1 effect on CW appeared to be independent of MAP kinase and Calcineurin pathway genes. Additionally, unlike hsf1 null strain, BER treatment of Candida cells resulted in dysfunctional mitochondria, which was evident from its slow growth in non-fermentative carbon source and poor labeling with mitochondrial membrane potential sensitive probe. This phenotype was reinforced with an enhanced ROS levels coinciding with the up-regulated oxidative stress genes in BER-treated cells. Together, our study not only describes the molecular mechanism of BER fungicidal activity but also unravels a new role of evolutionary conserved HSF1, in MDR of Candida. PMID:25105295

  19. Oral administration of the broad-spectrum antibiofilm compound toremifene inhibits Candida albicans and Staphylococcus aureus biofilm formation in vivo.

    PubMed

    De Cremer, Kaat; Delattin, Nicolas; De Brucker, Katrijn; Peeters, Annelies; Kucharíková, Soña; Gerits, Evelien; Verstraeten, Natalie; Michiels, Jan; Van Dijck, Patrick; Cammue, Bruno P A; Thevissen, Karin

    2014-12-01

    We here report on the in vitro activity of toremifene to inhibit biofilm formation of different fungal and bacterial pathogens, including Candida albicans, Candida glabrata, Candida dubliniensis, Candida krusei, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. We validated the in vivo efficacy of orally administered toremifene against C. albicans and S. aureus biofilm formation in a rat subcutaneous catheter model. Combined, our results demonstrate the potential of toremifene as a broad-spectrum oral antibiofilm compound. PMID:25288093

  20. The role of pattern recognition receptors in the innate recognition of Candida albicans.

    PubMed

    Zheng, Nan-Xin; Wang, Yan; Hu, Dan-Dan; Yan, Lan; Jiang, Yuan-Ying

    2015-01-01

    Candida albicans is both a commensal microorganism in healthy individuals and a major fungal pathogen causing high mortality in immunocompromised patients. Yeast-hypha morphological transition is a well known virulence trait of C. albicans. Host innate immunity to C. albicans critically requires pattern recognition receptors (PRRs). In this review, we summarize the PRRs involved in the recognition of C. albicans in epithelial cells, endothelial cells, and phagocytic cells separately. We figure out the differential recognition of yeasts and hyphae, the findings on PRR-deficient mice, and the discoveries on human PRR-related single nucleotide polymorphisms (SNPs).

  1. Cell wall-related bionumbers and bioestimates of Saccharomyces cerevisiae and Candida albicans.

    PubMed

    Klis, Frans M; de Koster, Chris G; Brul, Stanley

    2014-01-01

    Bionumbers and bioestimates are valuable tools in biological research. Here we focus on cell wall-related bionumbers and bioestimates of the budding yeast Saccharomyces cerevisiae and the polymorphic, pathogenic fungus Candida albicans. We discuss the linear relationship between cell size and cell ploidy, the correlation between cell size and specific growth rate, the effect of turgor pressure on cell size, and the reason why using fixed cells for measuring cellular dimensions can result in serious underestimation of in vivo values. We further consider the evidence that individual buds and hyphae grow linearly and that exponential growth of the population results from regular formation of new daughter cells and regular hyphal branching. Our calculations show that hyphal growth allows C. albicans to cover much larger distances per unit of time than the yeast mode of growth and that this is accompanied by strongly increased surface expansion rates. We therefore predict that the transcript levels of genes involved in wall formation increase during hyphal growth. Interestingly, wall proteins and polysaccharides seem barely, if at all, subject to turnover and replacement. A general lesson is how strongly most bionumbers and bioestimates depend on environmental conditions and genetic background, thus reemphasizing the importance of well-defined and carefully chosen culture conditions and experimental approaches. Finally, we propose that the numbers and estimates described here offer a solid starting point for similar studies of other cell compartments and other yeast species.

  2. 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. PMID:27256584

  3. Antifungal activity of Cymbopogon winterianus jowitt ex bor against Candida albicans

    PubMed Central

    de Oliveira, Wylly Araújo; de Oliveira Pereira, Fillipe; de Luna, Giliara Carol Diniz Gomes; Lima, Igara Oliveira; Wanderley, Paulo Alves; de Lima, Rita Baltazar; de Oliveira Lima, Edeltrudes

    2011-01-01

    Candida albicans is an opportunistic yeast and a member of the normal human flora that commonly causes infections in patients with any type of deficiency of the immune system. The essential oils have been tested for antimycotic activity and pose much potential as antifungal agents. This work investigated the activity of the essential oil of Cymbopogon winterianus against C. albicans by MIC, MFC and time-kill methods. The essential oil (EO) was obtained by hydrodistillation using a Clevenger-type apparatus. It was tested fifteen strains of C. albicans. The MIC was determined by the microdilution method and the MFC was determined when an aliquot of the broth microdilution was cultivated in SDA medium. The phytochemical analysis of EO showed presence of citronellal (23,59%), geraniol (18,81%) and citronellol (11,74%). The EO showed antifungal activity, and the concentrations 625 µg/mL and 1250 µg/mL inhibited the growth of all strains tested and it was fungicidal, respectively. The antimicrobial activity of various concentrations of EO was analyzed over time, it was found concentration-dependent antifungal activity, whose behavior was similar to amphotericin B and nystatin. PMID:24031651

  4. Characterisation of the Candida albicans Phosphopantetheinyl Transferase Ppt2 as a Potential Antifungal Drug Target

    PubMed Central

    Dobb, Katharine S.; Kaye, Sarah J.; Beckmann, Nicola; Thain, John L.; Stateva, Lubomira; Birch, Mike; Oliver, Jason D.

    2015-01-01

    Antifungal drugs acting via new mechanisms of action are urgently needed to combat the increasing numbers of severe fungal infections caused by pathogens such as Candida albicans. The phosphopantetheinyl transferase of Aspergillus fumigatus, encoded by the essential gene pptB, has previously been identified as a potential antifungal target. This study investigated the function of its orthologue in C. albicans, PPT2/C1_09480W by placing one allele under the control of the regulatable MET3 promoter, and deleting the remaining allele. The phenotypes of this conditional null mutant showed that, as in A. fumigatus, the gene PPT2 is essential for growth in C. albicans, thus fulfilling one aspect of an efficient antifungal target. The catalytic activity of Ppt2 as a phosphopantetheinyl transferase and the acyl carrier protein Acp1 as a substrate were demonstrated in a fluorescence transfer assay, using recombinant Ppt2 and Acp1 produced and purified from E.coli. A fluorescence polarisation assay amenable to high-throughput screening was also developed. Therefore we have identified Ppt2 as a broad-spectrum novel antifungal target and developed tools to identify inhibitors as potentially new antifungal compounds. PMID:26606674

  5. In vitro activity of xanthorrhizol isolated from the rhizome of Javanese turmeric (Curcuma xanthorrhiza Roxb.) against Candida albicans biofilms.

    PubMed

    Rukayadi, Yaya; Hwang, Jae-Kwan

    2013-07-01

    The purpose of this study was to investigate the activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. on Candida albicans biofilms at adherent, intermediate, and mature phase of growth. C. albicans biofilms were formed in flat-bottom 96-well microtiter plates. The biofilms of C. albicans at different phases of development were exposed to xanthorrhizol at different concentrations (0.5 µg/mL-256 µg/mL) for 24 h. The metabolic activity of cells within the biofilms was quantified using the XTT reduction assay. Sessile minimum inhibitory concentrations (SMICs) were determined at 50% and 80% reduction in the biofilm OD₄₉₀ compared to the control wells. The SMIC₅₀ and SMIC₈₀ of xanthorrhizol against 18 C. albicans biofilms were 4--16 µg/mL and 8--32 µg/mL, respectively. The results demonstrated that the activity of xanthorrhizol in reducing C. albicans biofilms OD₄₉₀ was dependent on the concentration and the phase of growth of biofilm. Xanthorrhizol at concentration of 8 µg/mL completely reduced in biofilm referring to XTT-colorimetric readings at adherent phase, whereas 32 µg/mL of xanthorrhizol reduced 87.95% and 67.48 % of biofilm referring to XTT-colorimetric readings at intermediate and mature phases, respectively. Xanthorrhizol displayed potent activity against C. albicans biofilms in vitro and therefore might have potential therapeutic implication for biofilm-associated candidal infections.

  6. Antifungal susceptibility and molecular typing of 115 Candida albicans isolates obtained from vulvovaginal candidiasis patients in 3 Shanghai maternity hospitals.

    PubMed

    Ying, Chunmei; Zhang, Hongju; Tang, Zhenhua; Chen, Huifen; Gao, Jing; Yue, Chaoyan

    2016-05-01

    In our multicenter study, we studied the distribution of Candida species in vulvovaginal candidiasis patients and investigated antifungal susceptibility profile and genotype of Candida albicans in vaginal swab. A total of 115 Candida albicans strains were detected in 135 clinical isolates. Minimum inhibitory concentration determinations showed that 83% and 81% of the 115 Candida albicans strains were susceptible to fluconazole and voriconazole. Randomly amplified polymorphic DNA analysis (RAPD) was applied to identify clonally related isolates from different patients at the local level. All tested strains were classified into genotype A (77.4%), genotype B (18.3%), and genotype C (4.3%). Genotype A was further classified into five subtypes and genotype B into two subtypes.Candida albicans was the dominant pathogen of vulvovaginal candidiasis, the majority belonging to genotype A in this study. Exposure to azoles is a risk factor for the emergence of azole resistance among Candida albicans isolated from VVC patients.

  7. Silicone colonization by non-Candida albicans Candida species in the presence of urine.

    PubMed

    Silva, Sónia; Negri, Melyssa; Henriques, Mariana; Oliveira, Rosário; Williams, David; Azeredo, Joana

    2010-07-01

    Urinary tract infections (UTIs) are the most common nosocomial infections and 80 % are related to the use of urinary catheters. Furthermore, Candida species are responsible for around 15 % of UTIs and an increasing involvement of non-Candida albicans Candida (NCAC) species (e.g. Candida glabrata, Candida tropicalis and Candida parapsilosis) has been recognized. Given the fact that silicone is frequently used in the manufacture of urinary catheters, the aim of this work was to compare both the adhesion and biofilm formation on silicone of different urinary clinical isolates of NCAC species (i.e. C. glabrata, C. tropicalis and C. parapsilosis) in the presence of urine. Several clinical isolates of NCAC species recovered from patients with UTIs, together with reference strains of each species, were examined. Adhesion and biofilm formation were performed in artificial urine and the biofilm biomass was assessed by crystal violet staining. Hydrophobicity and surface charge of cells was determined by measuring contact angles and zeta potential, respectively. The number of viable cells in biofilms was determined by enumeration of c.f.u. after appropriate culture. The biofilm structure was also examined by confocal laser scanning microscopy (CLSM). The results showed that all isolates adhered to silicone in a species- and strain-dependent manner with C. parapsilosis showing the lowest and C. glabrata the highest levels of adhesion. However, these differences in adhesion abilities cannot be correlated with surface properties since all strains examined were hydrophilic and exhibited a similar zeta potential. Despite a higher number of cultivable cells being recovered after 72 h of incubation, stronger biofilm formation was not observed and CLSM showed an absence of extracellular polymeric material for all isolates examined. In summary, this work demonstrated that all tested NCAC species were able to adhere to and survive on silicone in the presence of urine. Furthermore, C

  8. Host contributions to construction of three device-associated Candida albicans biofilms.

    PubMed

    Nett, Jeniel E; Zarnowski, Robert; Cabezas-Olcoz, Jonathan; Brooks, Erin G; Bernhardt, Jörg; Marchillo, Karen; Mosher, Deane F; Andes, David R

    2015-12-01

    Among the most fascinating virulence attributes of Candida is the ability to transition to a biofilm lifestyle. As a biofilm, Candida cells adhere to a surface, such as a vascular catheter, and become encased in an extracellular matrix. During this mode of growth, Candida resists the normal immune response, often causing devastating disease. Based on scanning electron microscopy images, we hypothesized that host cells and proteins become incorporated into clinical biofilms. As a means to gain an understanding of these host-biofilm interactions, we explored biofilm-associated host components by using microscopy and liquid chromatography-mass spectrometry. Here we characterize the host proteins associated with several in vivo rat Candida albicans biofilms, including those from vascular catheter, denture, and urinary catheter models as well as uninfected devices. A conserved group of 14 host proteins were found to be more abundant during infection at each of the niches. The host proteins were leukocyte and erythrocyte associated and included proteins involved in inflammation, such as C-reactive protein, myeloperoxidase, and alarmin S100-A9. A group of 59 proteins were associated with both infected and uninfected devices, and these included matricellular and inflammatory proteins. In addition, site-specific proteins were identified, such as amylase in association with the denture device. Cellular analysis revealed neutrophils as the predominant leukocytes associating with biofilms. These experiments demonstrate that host cells and proteins are key components of in vivo Candida biofilms, likely with one subset associating with the device and another being recruited by the proliferating biofilm.

  9. Host contributions to construction of three device-associated Candida albicans biofilms.

    PubMed

    Nett, Jeniel E; Zarnowski, Robert; Cabezas-Olcoz, Jonathan; Brooks, Erin G; Bernhardt, Jörg; Marchillo, Karen; Mosher, Deane F; Andes, David R

    2015-12-01

    Among the most fascinating virulence attributes of Candida is the ability to transition to a biofilm lifestyle. As a biofilm, Candida cells adhere to a surface, such as a vascular catheter, and become encased in an extracellular matrix. During this mode of growth, Candida resists the normal immune response, often causing devastating disease. Based on scanning electron microscopy images, we hypothesized that host cells and proteins become incorporated into clinical biofilms. As a means to gain an understanding of these host-biofilm interactions, we explored biofilm-associated host components by using microscopy and liquid chromatography-mass spectrometry. Here we characterize the host proteins associated with several in vivo rat Candida albicans biofilms, including those from vascular catheter, denture, and urinary catheter models as well as uninfected devices. A conserved group of 14 host proteins were found to be more abundant during infection at each of the niches. The host proteins were leukocyte and erythrocyte associated and included proteins involved in inflammation, such as C-reactive protein, myeloperoxidase, and alarmin S100-A9. A group of 59 proteins were associated with both infected and uninfected devices, and these included matricellular and inflammatory proteins. In addition, site-specific proteins were identified, such as amylase in association with the denture device. Cellular analysis revealed neutrophils as the predominant leukocytes associating with biofilms. These experiments demonstrate that host cells and proteins are key components of in vivo Candida biofilms, likely with one subset associating with the device and another being recruited by the proliferating biofilm. PMID:26371129

  10. Host Contributions to Construction of Three Device-Associated Candida albicans Biofilms

    PubMed Central

    Nett, Jeniel E.; Zarnowski, Robert; Cabezas-Olcoz, Jonathan; Brooks, Erin G.; Bernhardt, Jörg; Marchillo, Karen; Mosher, Deane F.

    2015-01-01

    Among the most fascinating virulence attributes of Candida is the ability to transition to a biofilm lifestyle. As a biofilm, Candida cells adhere to a surface, such as a vascular catheter, and become encased in an extracellular matrix. During this mode of growth, Candida resists the normal immune response, often causing devastating disease. Based on scanning electron microscopy images, we hypothesized that host cells and proteins become incorporated into clinical biofilms. As a means to gain an understanding of these host-biofilm interactions, we explored biofilm-associated host components by using microscopy and liquid chromatography-mass spectrometry. Here we characterize the host proteins associated with several in vivo rat Candida albicans biofilms, including those from vascular catheter, denture, and urinary catheter models as well as uninfected devices. A conserved group of 14 host proteins were found to be more abundant during infection at each of the niches. The host proteins were leukocyte and erythrocyte associated and included proteins involved in inflammation, such as C-reactive protein, myeloperoxidase, and alarmin S100-A9. A group of 59 proteins were associated with both infected and uninfected devices, and these included matricellular and inflammatory proteins. In addition, site-specific proteins were identified, such as amylase in association with the denture device. Cellular analysis revealed neutrophils as the predominant leukocytes associating with biofilms. These experiments demonstrate that host cells and proteins are key components of in vivo Candida biofilms, likely with one subset associating with the device and another being recruited by the proliferating biofilm. PMID:26371129

  11. Candida albicans Is Phagocytosed, Killed, and Processed for Antigen Presentation by Human Dendritic Cells

    PubMed Central

    Newman, Simon L.; Holly, Angela

    2001-01-01

    Candida albicans is a component of the normal flora of the alimentary tract and also is found on the mucocutaneous membranes of the healthy host. Candida is the leading cause of invasive fungal disease in premature infants, diabetics, and surgical patients, and of oropharyngeal disease in AIDS patients. As the induction of cell-mediated immunity to Candida is of critical importance in host defense, we sought to determine whether human dendritic cells (DC) could phagocytose and degrade Candida and subsequently present Candida antigens to T cells. Immature DC obtained by culture of human monocytes in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4 phagocytosed unopsonized Candida in a time-dependent manner, and phagocytosis was not enhanced by opsonization of Candida in serum. Like macrophages (Mφ), DC recognized Candida by the mannose-fucose receptor. Upon ingestion, DC killed Candida as efficiently as human Mφ, and fungicidal activity was not enhanced by the presence of fresh serum. Although phagocytosis of Candida by DC stimulated the production of superoxide anion, inhibitors of the respiratory burst (or NO production) did not inhibit killing of Candida, even when phagocytosis was blocked by preincubation of DC with cytochalasin D. Further, although apparently only modest phagolysosomal fusion occurred upon DC phagocytosis of Candida, killing of Candida under anaerobic conditions was almost equivalent to killing under aerobic conditions. Finally, DC stimulated Candida-specific lymphocyte proliferation in a concentration-dependent manner after phagocytosis of both viable and heat-killed Candida cells. These data suggest that, in vivo, such interactions between DC and C. albicans may facilitate the induction of cell-mediated immunity. PMID:11598054

  12. Person-to-person transfer of Candida albicans in the spacecraft environment

    NASA Technical Reports Server (NTRS)

    Pierson, D. L.; Mehta, S. K.; Magee, B. B.; Mishra, S. K.

    1995-01-01

    We assessed the exchange of Candida albicans among crew members during 10 Space Shuttle missions. Throat, nasal, urine and faecal specimens were collected from 61 crew members twice before and once after space flights ranging from 7 to 10 days in duration; crews consisted of groups of five, six or seven men and women. Candida albicans was isolated at least once from 20 of the 61 subjects (33%). Candida strains were identified by restriction-fragment length polymorphism (RFLP) after digestion by the endonucleases EcoRI and HinfI; further discrimination was gained by Southern blot hybridization with the C. albicans repeat fragment 27A. Eighteen of the 20 Candida-positive crew members carried different strains of C. albicans in the specimens collected. Possible transfer of C. albicans between members of the same crew was demonstrated only once in the 10 missions studied. We conclude that the transfer of C. albicans among crew members during Space Shuttle flights is less frequent than had been predicted from earlier reports.

  13. Cell wall protection by the Candida albicans class I chitin synthases

    PubMed Central

    Preechasuth, Kanya; Anderson, Jeffrey C.; Peck, Scott C.; Brown, Alistair J.P.; Gow, Neil A.R.; Lenardon, Megan D.

    2015-01-01

    Candida albicans has four chitin synthases from three different enzyme classes which deposit chitin in the cell wall, including at the polarized tips of growing buds and hyphae, and sites of septation. The two class I enzymes, Chs2 and Chs8, are responsible for most of the measurable chitin synthase activity in vitro, but their precise biological functions in vivo remain obscure. In this work, detailed phenotypic analyses of a chs2Δchs8Δ mutant have shown that C. albicans class I chitin synthases promote cell integrity during early polarized growth in yeast and hyphal cells. This was supported by live cell imaging of YFP-tagged versions of the class I chitin synthases which revealed that Chs2-YFP was localized at sites of polarized growth. Furthermore, a unique and dynamic pattern of localization of the class I enzymes at septa of yeast and hyphae was revealed. Phosphorylation of Chs2 on the serine at position 222 was shown to regulate the amount of Chs2 that is localized to sites of polarized growth and septation. Independently from this post-translational modification, specific cell wall stresses were also shown to regulate the amount of Chs2 that localizes to specific sites in cells, and this was linked to the ability of the class I enzymes to reinforce cell wall integrity during early polarized growth in the presence of these stresses. PMID:26257018

  14. Distinct mechanisms of epithelial adhesion for Candida albicans and Candida tropicalis. Identification of the participating ligands and development of inhibitory peptides.

    PubMed Central

    Bendel, C M; Hostetter, M K

    1993-01-01

    The yeast Candida albicans is the leading cause of disseminated fungal infection in neonates, immunocompromised hosts, diabetics, and postoperative patients; Candida tropicalis is the second most frequent isolate. Because the integrin analogue in C. albicans shares antigenic, structural, and functional homologies with the beta 2-integrin subunits alpha M and alpha X, we investigated the role of integrin analogues in epithelial adhesion of C. albicans and C. tropicalis. On flow cytometry with the monoclonal antibody (mAb) OKM1, surface fluorescence was highest for C. albicans and significantly reduced for C. tropicalis (P < 0.001). However, adhesion to the human epithelial cell line HeLa S3 did not differ for these two candidal species: specific adhesion was highest for C. albicans at 44.0 +/- 1.8%, and only slightly lower for C. tropicalis at 38.8 +/- 3.6% (P = NS). The disparity between expression of the integrin analogue and epithelial adhesion suggested distinct mechanisms for this process in C. albicans versus C. tropicalis. Preincubation of C. albicans with anti-alpha M mAbs, with purified iC3b (the RGD ligand for the integrin analogue), or with 9-15-mer RGD peptides from iC3b all inhibited epithelial adhesion significantly (P < 0.001-0.04). Purified fibronectin or fibronectin-RGD peptides failed to block C. albicans adhesion. In contrast, epithelial adhesion of C. tropicalis was significantly inhibited by purified fibronectin and its RGD peptides (P < or = 0.021), but not by iC3b nor the iC3b-RGD peptides. Both iC3b and fibronectin were identified on the surface of epithelial cells after growth in serum-free medium. A polyclonal antibody to C3 inhibited C. albicans adhesion while a control antibody to fibronectin was ineffective; the converse was true for C. tropicalis. These results indicate that the pathogenic yeasts C. albicans and C. tropicalis recognize distinct RGD ligands present at the surface of the epithelial cell and that these interactions can be

  15. [Activity of ajoene on dermatophytes, Candida albicans and Malassezia furfur.].

    PubMed

    de González, M I; Mendoza, M; Bastardo de Albornoz, M; Apitz-Castro, R

    1998-12-01

    The sensitivity in vitro of an isolate of Trichophyton rubrum and another of Trichophyton mentagrophytes to ajoene. This compound inhibited the growth of both isolates, showing an minimal inhibitory concentration (MIC) of 60 microg/ml and a minimal fungicidal concentration (MFC) of 75 microg/ml. In vivo, the ajoene cream at 0.4% used once a day and every five days in 38 patients (thirty dermatophytosis and eight Candida intertrigo cases) achieved a low percentage of cures (23.3% and 12.5%, respectively). However, an excellent clinic response was obtained in eight patients with pityriasis versicolor, with a cure in 87.5% of the cases.

  16. [A case report of pulmonary infiltration with eosinophilia syndrome induced by Candida albicans].

    PubMed

    Miyagawa, H; Yokota, S; Kajimoto, K; Makimoto, K; Sato, K; Nabe, M; Tada, S; Kimura, I

    1992-01-01

    A sixty six-year-old female who had been treated for bronchial asthma for about 25 years was admitted to the hospital with complaints of episodes of dyspnea, eosinophilia and infiltrative shadows in the chest X-ray film. An infiltrative shadow appeared to move from the left to the right lung field and finally formed a shadow of atelectasis in the middle field of the right lung. A sputum culture showed only Candida albicans. Allergic and immunologic examination revealed high IgE serum levels with specific IgE against Candida albicans in high titer, and Aspergillus fumigatus in low titer. The precipitating antibody was shown only against Candida antigen. Additionally, the blastogenic response to Candida antigen was high in comparison with other fungal antigens including Aspergillus fumigatus. The clinical features and laboratory findings of this patient were found to satisfy Rosenberg's criteria for allergic bronchopulmonary aspergillosis (ABPA), except for the existence of Candida albicans in place of Aspergillus species as the causative antigen. The pathogenesis of PIE syndrome has been studied and various allergic mechanisms against many antigens reported. In this patient Candida albicans could be playing the crucial role in the formation of PIE syndrome, which might be best described as allergic bronchopulmonary candidiasis (ABPC). PMID:1554325

  17. Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis

    PubMed Central

    Lopez-Medina, Eduardo; Fan, Di; Coughlin, Laura A.; Ho, Evi X.; Lamont, Iain L.; Reimmann, Cornelia; Hooper, Lora V.; Koh, Andrew Y.

    2015-01-01

    Bacterial-fungal interactions have important physiologic and medical ramifications, but the mechanisms of these interactions are poorly understood. The gut is host to trillions of microorganisms, and bacterial-fungal interactions are likely to be important. Using a neutropenic mouse model of microbial gastrointestinal colonization and dissemination, we show that the fungus Candida albicans inhibits the virulence of the bacterium Pseudomonas aeruginosa by inhibiting P. aeruginosa pyochelin and pyoverdine gene expression, which plays a critical role in iron acquisition and virulence. Accordingly, deletion of both P. aeruginosa pyochelin and pyoverdine genes attenuates P. aeruginosa virulence. Heat-killed C. albicans has no effect on P. aeruginosa, whereas C. albicans secreted proteins directly suppress P. aeruginosa pyoverdine and pyochelin expression and inhibit P. aeruginosa virulence in mice. Interestingly, suppression or deletion of pyochelin and pyoverdine genes has no effect on P. aeruginosa’s ability to colonize the GI tract but does decrease P. aeruginosa’s cytotoxic effect on cultured colonocytes. Finally, oral iron supplementation restores P. aeruginosa virulence in P. aeruginosa and C. albicans colonized mice. Together, our findings provide insight into how a bacterial-fungal interaction can modulate bacterial virulence in the intestine. Previously described bacterial-fungal antagonistic interactions have focused on growth inhibition or colonization inhibition/modulation, yet here we describe a novel observation of fungal-inhibition of bacterial effectors critical for virulence but not important for colonization. These findings validate the use of a mammalian model system to explore the complexities of polymicrobial, polykingdom infections in order to identify new therapeutic targets for preventing microbial disease. PMID:26313907

  18. Phenylpropanoids of plant origin as inhibitors of biofilm formation by Candida albicans.

    PubMed

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

    2014-09-01

    Biofilm-related infections of Candida albicans are a frequent cause of morbidity and mortality in hospitalized patients, especially those with immunocompromised status. Options of the antifungal drugs available for successful treatment of drug-resistant biofilms are very few, and as such, new strategies need to be explored against them. The aim of this study was to evaluate the efficacy of phenylpropanoids of plant origin against planktonic cells, important virulence factors, and biofilm forms of C. albicans. Standard susceptibility testing protocol was used to evaluate the activities of 13 phenylpropanoids against planktonic growth. Their effects on adhesion and yeast-to-hyphae morphogenesis were studied in microplate-based methodologies. An in vitro biofilm model analyzed the phenylpropanoid-mediated prevention of biofilm development and mature biofilms using XTT-metabolic assay, crystal violet assay, and light microscopy. Six molecules exhibited fungistatic activity at ≤0.5 mg/ml, of which four were fungicidal at low concentrations. Seven phenylpropanoids inhibited yeast-to-hyphae transition at low concentrations (0.031-0.5 mg/ml), whereas adhesion to the solid substrate was prevented in the range of 0.5-2 mg/ml. Treatment with ≤0.5 mg/ml concentrations of at least six small molecules resulted in significant (p < 0.05) inhibition of biofilm formation by C. albicans. Mature biofilms that are highly resistant to antifungal drugs were susceptible to low concentrations of 4 of the 13 molecules. This study revealed phenylpropanoids of plant origin as promising candidates to devise preventive strategies against drug-resistant biofilms of C. albicans. PMID:24851813

  19. The Candida albicans CDR3 gene codes for an opaque-phase ABC transporter.

    PubMed Central

    Balan, I; Alarco, A M; Raymond, M

    1997-01-01

    We report the cloning and functional analysis of a third member of the CDR gene family in Candida albicans, named CDR3. This gene codes for an ABC (ATP-binding cassette) transporter of 1,501 amino acids highly homologous to Cdr1p and Cdr2p (56 and 55% amino acid sequence identity, respectively), two transporters involved in fluconazole resistance in C. albicans. The predicted structure of Cdr3p is typical of the PDR/CDR family, with two similar halves, each comprising an N-terminal hydrophilic domain with consensus sequences for ATP binding and a C-terminal hydrophobic domain with six predicted transmembrane segments. Northern analysis showed that CDR3 expression is regulated in a cell-type-specific manner, with low levels of CDR3 mRNA in CAI4 yeast and hyphal cells, high levels in WO-1 opaque cells, and undetectable levels in WO-1 white cells. Disruption of both alleles of CDR3 in CAI4 resulted in no obvious changes in cell morphology, growth rate, or susceptibility to fluconazole. Overexpression of Cdr3p in C. albicans did not result in increased cellular resistance to fluconazole, cycloheximide, and 4-nitroquinoline-N-oxide, which are known substrates for different transporters of the PDR/CDR family. These results indicate that despite a high degree of sequence conservation with C. albicans Cdr1p and Cdr2p, Cdr3p does not appear to be involved in drug resistance, at least to the compounds tested which include the clinically relevant antifungal agent fluconazole. Rather, the high level of Cdr3p expression in WO-1 opaque cells suggests an opaque-phase-associated biological function which remains to be identified. PMID:9393682

  20. Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis.

    PubMed

    Lopez-Medina, Eduardo; Fan, Di; Coughlin, Laura A; Ho, Evi X; Lamont, Iain L; Reimmann, Cornelia; Hooper, Lora V; Koh, Andrew Y

    2015-08-01

    Bacterial-fungal interactions have important physiologic and medical ramifications, but the mechanisms of these interactions are poorly understood. The gut is host to trillions of microorganisms, and bacterial-fungal interactions are likely to be important. Using a neutropenic mouse model of microbial gastrointestinal colonization and dissemination, we show that the fungus Candida albicans inhibits the virulence of the bacterium Pseudomonas aeruginosa by inhibiting P. aeruginosa pyochelin and pyoverdine gene expression, which plays a critical role in iron acquisition and virulence. Accordingly, deletion of both P. aeruginosa pyochelin and pyoverdine genes attenuates P. aeruginosa virulence. Heat-killed C. albicans has no effect on P. aeruginosa, whereas C. albicans secreted proteins directly suppress P. aeruginosa pyoverdine and pyochelin expression and inhibit P. aeruginosa virulence in mice. Interestingly, suppression or deletion of pyochelin and pyoverdine genes has no effect on P. aeruginosa's ability to colonize the GI tract but does decrease P. aeruginosa's cytotoxic effect on cultured colonocytes. Finally, oral iron supplementation restores P. aeruginosa virulence in P. aeruginosa and C. albicans colonized mice. Together, our findings provide insight into how a bacterial-fungal interaction can modulate bacterial virulence in the intestine. Previously described bacterial-fungal antagonistic interactions have focused on growth inhibition or colonization inhibition/modulation, yet here we describe a novel observation of fungal-inhibition of bacterial effectors critical for virulence but not important for colonization. These findings validate the use of a mammalian model system to explore the complexities of polymicrobial, polykingdom infections in order to identify new therapeutic targets for preventing microbial disease. PMID:26313907

  1. Binary Interactions of Antagonistic Bacteria with Candida albicans Under Aerobic and Anaerobic Conditions.

    PubMed

    Benadé, Eliska; Stone, Wendy; Mouton, Marnel; Postma, Ferdinand; Wilsenach, Jac; Botha, Alfred

    2016-04-01

    We used both aerobic and anaerobic liquid co-cultures, prepared with Luria Bertani broth, to study the effect of bacteria on the survival of Candida albicans in the external environment, away from an animal host. The bacteria were represented by Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Clostridium, Enterobacter, Klebsiella pneumoniae, Kluyvera ascorbata and Serratia marcescens. Under aerobic conditions, the yeast's growth was inhibited in the presence of bacterial growth; however, under anaerobic conditions, yeast and bacterial growth in co-cultures was similar to that observed for pure cultures. Subsequent assays revealed that the majority of bacterial strains aerobically produced extracellular hydrolytic enzymes capable of yeast cell wall hydrolysis, including chitinases and mannan-degrading enzymes. In contrast, except for the A. hydrophila strain, these enzymes were not detected in anaerobic bacterial cultures, nor was the antimicrobial compound prodigiosin found in anaerobic cultures of S. marcescens. When we suspended C. albicans cells in crude extracellular enzyme preparations from K. pneumoniae and S. marcescens, we detected no negative effect on yeast viability. However, we found that these preparations enhance the toxicity of prodigiosin towards the yeast, especially in combination with mannan-degrading enzymes. Analyses of the chitin and mannan content of yeast cell walls revealed that less chitin was produced under anaerobic than aerobic conditions; however, the levels of mannan, known for its low permeability, remained the same. The latter phenomenon, as well as reduced production of the bacterial enzymes and prodigiosin, may contribute to anaerobic growth and survival of C. albicans in the presence of bacteria.

  2. Binary Interactions of Antagonistic Bacteria with Candida albicans Under Aerobic and Anaerobic Conditions.

    PubMed

    Benadé, Eliska; Stone, Wendy; Mouton, Marnel; Postma, Ferdinand; Wilsenach, Jac; Botha, Alfred

    2016-04-01

    We used both aerobic and anaerobic liquid co-cultures, prepared with Luria Bertani broth, to study the effect of bacteria on the survival of Candida albicans in the external environment, away from an animal host. The bacteria were represented by Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Clostridium, Enterobacter, Klebsiella pneumoniae, Kluyvera ascorbata and Serratia marcescens. Under aerobic conditions, the yeast's growth was inhibited in the presence of bacterial growth; however, under anaerobic conditions, yeast and bacterial growth in co-cultures was similar to that observed for pure cultures. Subsequent assays revealed that the majority of bacterial strains aerobically produced extracellular hydrolytic enzymes capable of yeast cell wall hydrolysis, including chitinases and mannan-degrading enzymes. In contrast, except for the A. hydrophila strain, these enzymes were not detected in anaerobic bacterial cultures, nor was the antimicrobial compound prodigiosin found in anaerobic cultures of S. marcescens. When we suspended C. albicans cells in crude extracellular enzyme preparations from K. pneumoniae and S. marcescens, we detected no negative effect on yeast viability. However, we found that these preparations enhance the toxicity of prodigiosin towards the yeast, especially in combination with mannan-degrading enzymes. Analyses of the chitin and mannan content of yeast cell walls revealed that less chitin was produced under anaerobic than aerobic conditions; however, the levels of mannan, known for its low permeability, remained the same. The latter phenomenon, as well as reduced production of the bacterial enzymes and prodigiosin, may contribute to anaerobic growth and survival of C. albicans in the presence of bacteria. PMID:26566932

  3. An Optimized Lock Solution Containing Micafungin, Ethanol and Doxycycline Inhibits Candida albicans and Mixed C. albicans – Staphyloccoccus aureus Biofilms

    PubMed Central

    Lown, Livia; Peters, Brian M.; Walraven, Carla J.; Noverr, Mairi C.; Lee, Samuel A.

    2016-01-01

    Candida albicans is a major cause of catheter-related bloodstream infections and is associated with high morbidity and mortality. Due to the propensity of C. albicans to form drug-resistant biofilms, the current standard of care includes catheter removal; however, reinsertion may be technically challenging or risky. Prolonged exposure of an antifungal lock solution within the catheter in conjunction with systemic therapy has been experimentally attempted for catheter salvage. Previously, we demonstrated excellent in vitro activity of micafungin, ethanol, and high-dose doxycycline as single agents for prevention and treatment of C. albicans biofilms. Thus, we sought to investigate optimal combinations of micafungin, ethanol, and/or doxycycline as a lock solution. We performed two- and three-drug checkerboard assays to determine the in vitro activity of pairwise or three agents in combination for prevention or treatment of C. albicans biofilms. Optimal lock solutions were tested for activity against C. albicans clinical isolates, reference strains and polymicrobial C. albicans-S. aureus biofilms. A solution containing 20% (v/v) ethanol, 0.01565 μg/mL micafungin, and 800 μg/mL doxycycline demonstrated a reduction of 98% metabolic activity and no fungal regrowth when used to prevent fungal biofilm formation; however there was no advantage over 20% ethanol alone. This solution was also successful in inhibiting the regrowth of C. albicans from mature polymicrobial biofilms, although it was not fully bactericidal. Solutions containing 5% ethanol with low concentrations of micafungin and doxycycline demonstrated synergistic activity when used to prevent monomicrobial C. albicans biofilm formation. A combined solution of micafungin, ethanol and doxycycline is highly effective for the prevention of C. albicans biofilm formation but did not demonstrate an advantage over 20% ethanol alone in these studies. PMID:27428310

  4. An Optimized Lock Solution Containing Micafungin, Ethanol and Doxycycline Inhibits Candida albicans and Mixed C. albicans - Staphyloccoccus aureus Biofilms.

    PubMed

    Lown, Livia; Peters, Brian M; Walraven, Carla J; Noverr, Mairi C; Lee, Samuel A

    2016-01-01

    Candida albicans is a major cause of catheter-related bloodstream infections and is associated with high morbidity and mortality. Due to the propensity of C. albicans to form drug-resistant biofilms, the current standard of care includes catheter removal; however, reinsertion may be technically challenging or risky. Prolonged exposure of an antifungal lock solution within the catheter in conjunction with systemic therapy has been experimentally attempted for catheter salvage. Previously, we demonstrated excellent in vitro activity of micafungin, ethanol, and high-dose doxycycline as single agents for prevention and treatment of C. albicans biofilms. Thus, we sought to investigate optimal combinations of micafungin, ethanol, and/or doxycycline as a lock solution. We performed two- and three-drug checkerboard assays to determine the in vitro activity of pairwise or three agents in combination for prevention or treatment of C. albicans biofilms. Optimal lock solutions were tested for activity against C. albicans clinical isolates, reference strains and polymicrobial C. albicans-S. aureus biofilms. A solution containing 20% (v/v) ethanol, 0.01565 μg/mL micafungin, and 800 μg/mL doxycycline demonstrated a reduction of 98% metabolic activity and no fungal regrowth when used to prevent fungal biofilm formation; however there was no advantage over 20% ethanol alone. This solution was also successful in inhibiting the regrowth of C. albicans from mature polymicrobial biofilms, although it was not fully bactericidal. Solutions containing 5% ethanol with low concentrations of micafungin and doxycycline demonstrated synergistic activity when used to prevent monomicrobial C. albicans biofilm formation. A combined solution of micafungin, ethanol and doxycycline is highly effective for the prevention of C. albicans biofilm formation but did not demonstrate an advantage over 20% ethanol alone in these studies. PMID:27428310

  5. Avian pox infection with secondary Candida albicans encephalitis in a juvenile golden eagle (Aquila chrysaetos).

    PubMed

    Shrubsole-Cockwill, Alana N; Millins, Caroline; Jardine, Claire; Kachur, Kelti; Parker, Dennilyn L

    2010-03-01

    Abstract: A juvenile golden eagle (Aquila chrysaetos) was presented with proliferative epithelial lesions, consistent with avian poxvirus infection, around the eyes, on commissures of the beak, and on both feet. Despite treatment, the eagle declined clinically, and, 15 days after presentation, the eagle began seizuring and was euthanatized because of a poor prognosis. On postmortem examination, avian poxvirus infection was confirmed in the nodular skin lesions, and Candida albicans was cultured from the skin, lungs, and brain. Breaks in the skin barrier from poxvirus infection likely led to secondary infection with C albicans. Systemic vascular dissemination of C albicans to the brain resulted in thrombosis, hemorrhage, local hypoxia, and the clinically observed seizures. The combination of the breach in the primary immune system, immunosuppression, and a prolonged course of antibiotics were contributory factors to the opportunistic fungal infection in this eagle. Candida albicans should be considered as a differential diagnosis for encephalitis in an immunocompromised avian patient. PMID:20496607

  6. Study on the Structure of Candida Albicans-Staphylococcus Epidermidis Mixed Species Biofilm on Polyvinyl Chloride Biomaterial.

    PubMed

    Chen, Ying; Wang, Xiao-Yan; Huang, Yun-Chao; Zhao, Guang-Qiang; Lei, Yu-Jie; Ye, Lian-Hua; Huang, Qiu-Bo; Duan, Wan-Shi

    2015-11-01

    The objective of the study was to establish an in vitro model of Candida albicans-Staphylococcus epidermidis mixed species biofilm (BF) on polyvinyl chloride (PVC) material, and to investigate the formation and the structure of mixed species BF formation using a combined approach of confocal laser scanning microscope (CLSM), scanning electron microscope (SEM), and 3D image reconstruction technique. Mixed species BF is achieved by co-incubating Staphylococcus epidermidis bacteria (ATCC35984) and Candida albicans fungal (ATCC10231) with PVC pieces in Tris-buffered saline. BF formation was examined at 2, 6, 12, 24, 48, and 72 h of co-culture. Thickness of these BFs and the number, and percentage of viable cells in BFs were measured. CT scan images of BFs were obtained using CLSM and SEM and reconstructed 3D images of mixed species BF were acquired, in an effort to examine structure of the BF. Staphylococcus epidermidis attached to various forms of candida albicans (spores, pseudohyphae, and hyphae), formed complex and dense mesh arrays. The BF is constituted of a large number of viable and dead pathogens, the surface of mixed species BF is uneven, with living pathogens predominating protrusive portions and dead pathogens aggregating in concaves. Mixed species BF formation on the surface of PVC material was found to be a dynamic process, with rapid growth being at 24 h of co-culture, maximal thickness peaked at 48 h. These mixed species BF matured at 48-72 h. Significant differences were observed in the proportion of viable cells between interior, middle, and outer layers of BFs (p < 0.05). Mixed species BF Candida albicans-Staphylococcus epidermidis is sophisticated in structure. The combined approach involving CLSM, SEM, and 3D image reconstruction technique is ideal for the investigation of mixed species BF on PVC material.

  7. Study on the Structure of Candida Albicans-Staphylococcus Epidermidis Mixed Species Biofilm on Polyvinyl Chloride Biomaterial.

    PubMed

    Chen, Ying; Wang, Xiao-Yan; Huang, Yun-Chao; Zhao, Guang-Qiang; Lei, Yu-Jie; Ye, Lian-Hua; Huang, Qiu-Bo; Duan, Wan-Shi

    2015-11-01

    The objective of the study was to establish an in vitro model of Candida albicans-Staphylococcus epidermidis mixed species biofilm (BF) on polyvinyl chloride (PVC) material, and to investigate the formation and the structure of mixed species BF formation using a combined approach of confocal laser scanning microscope (CLSM), scanning electron microscope (SEM), and 3D image reconstruction technique. Mixed species BF is achieved by co-incubating Staphylococcus epidermidis bacteria (ATCC35984) and Candida albicans fungal (ATCC10231) with PVC pieces in Tris-buffered saline. BF formation was examined at 2, 6, 12, 24, 48, and 72 h of co-culture. Thickness of these BFs and the number, and percentage of viable cells in BFs were measured. CT scan images of BFs were obtained using CLSM and SEM and reconstructed 3D images of mixed species BF were acquired, in an effort to examine structure of the BF. Staphylococcus epidermidis attached to various forms of candida albicans (spores, pseudohyphae, and hyphae), formed complex and dense mesh arrays. The BF is constituted of a large number of viable and dead pathogens, the surface of mixed species BF is uneven, with living pathogens predominating protrusive portions and dead pathogens aggregating in concaves. Mixed species BF formation on the surface of PVC material was found to be a dynamic process, with rapid growth being at 24 h of co-culture, maximal thickness peaked at 48 h. These mixed species BF matured at 48-72 h. Significant differences were observed in the proportion of viable cells between interior, middle, and outer layers of BFs (p < 0.05). Mixed species BF Candida albicans-Staphylococcus epidermidis is sophisticated in structure. The combined approach involving CLSM, SEM, and 3D image reconstruction technique is ideal for the investigation of mixed species BF on PVC material. PMID:27352339

  8. Dentinal Tubule Disinfection with Propolis & Two Extracts of Azadirachta indica Against Candida albicans Biofilm Formed on Tooth Substrate

    PubMed Central

    Joy Sinha, Dakshita; Garg, Paridhi; Verma, Anurag; Malik, Vibha; Maccune, Edgar Richard; Vasudeva, Agrima

    2015-01-01

    Aim: This study evaluates the disinfection of dentinal tubules using Propolis, Azadirachta indica (alcoholic and aqueous extracts), 2% chlorhexidine gel and calcium hydroxide against Candida albicans biofilm formed on tooth substrate. Materials & Method: One hundred and five human teeth were infected with Candida albicans for 2 days. Samples were divided into 7 groups. Group I- Propolis, Group II- Alcoholic extract of Azadirachta indica, Group III- Aqueous extract of Azadirachta indica, Group IV- 2% Chlorhexidine, Group V- Calcium hydroxide, Group VI- Ethanol and Group VII- Saline (negative control). At the end of 1,3 and 5 days, the antimicrobial efficacy of medicaments against Candida albicans was assessed at the depths of 200 µm and 400 µm. Results: The overall percentage inhibition of fungal growth (at 200 µm and 400 µm depth) was 99.2% with 2% chlorhexidine gel. There was no statistical difference between propolis, alcoholic extract of Azadirachta indica (neem) and 2% chlorhexidine. Conclusion: Propolis and alcoholic extract of Azadirachta indica performed equally well as that of 2% Chlorhexidine. PMID:26962368

  9. Reduced inhibition of Candida albicans adhesion by saliva from patients receiving oral cancer therapy.

    PubMed Central

    Umazume, M; Ueta, E; Osaki, T

    1995-01-01

    The effect of saliva on the adhesion of Candida albicans to epithelial cells was examined in vitro by using saliva from healthy controls and patients with oral squamous cell carcinoma. The adhesion of C. albicans to established epithelial tumor cells was reduced by 40% by salivary treatment of the C. albicans or epithelial cells. The inhibitory activity of saliva was almost completely abolished by anti-secretory immunoglobulin A antibody, concanavalin A, and mannose. Compared with saliva from healthy individuals, that from patients who had received chemoradiotherapy for oral carcinoma showed reduced suppression of C. albicans adhesion, which accompanied decreased salivary secretory immunoglobulin A and lactoferrin concentrations. A greater number of C. albicans cells adhered to buccal cells obtained from patients who had received chemoradiotherapy than to those from healthy individuals. Treatment of either epithelial cells or C. albicans with anticancer drugs induced an increase in adherence of epithelial cells and yeast cells. In contrast, concanavalin A- and mannose-pretreated C. albicans exhibited reduced adhesion to epithelial cells. No further decrease of C. albicans adhesion was observed when both epithelial cells and yeast phase C. albicans were treated with mannose. In conclusion, the inhibition of C. albicans adhesion by saliva depends largely on mannose residues on salivary glycoproteins and mannose is one of the binding ligands on both C. albicans and epithelial cells. In addition, anticancer therapy may induce oral C. albicans overgrowth by decreasing salivation and the concentrations of glycoproteins in saliva inhibiting C. albicans adhesion and by increasing the adhesive properties of both C. albicans and oral epithelial cells. PMID:7714204

  10. Examination of the pathogenic potential of Candida albicans filamentous cells in an animal model of haematogenously disseminated candidiasis.

    PubMed

    Cleary, Ian A; Reinhard, Sara M; Lazzell, Anna L; Monteagudo, Carlos; Thomas, Derek P; Lopez-Ribot, Jose L; Saville, Stephen P

    2016-03-01

    The opportunistic fungal pathogen Candida albicans is an increasingly common threat to human health. Candida albicans grows in several morphologies and mutant strains locked in yeast or filamentous forms have attenuated virulence in the murine model of disseminated candidiasis. Thus, the ability to change shape is important for virulence. The transcriptional repressors Nrg1p and Tup1p are required for normal regulation of C. albicans morphology. Strains lacking either NRG1 or TUP1 are constitutively pseudohyphal under yeast growth conditions, and display attenuated virulence in the disseminated model. To dissect the relative importance of hyphae and pseudohyphae during an infection, we used strains in which the morphological transition could be externally manipulated through controlled expression of NRG1 or TUP1. Remarkably, hyphal form inocula retain the capacity to cause disease. Whilst induction of a pseudohyphal morphology through depletion of TUP1 did result in attenuated virulence, this was not due to a defect in the ability to escape the bloodstream. Instead, we observed that pseudohyphal cells are cleared from tissues much more efficiently than either hyphal (virulent) or yeast form (avirulent) cells, indicating that different C. albicans morphologies have distinct interactions with host cells during an infection.

  11. Candida albicans and non-albicans species as etiological agent of vaginitis in pregnant and non-pregnant women.

    PubMed

    Babic, Mirela; Hukic, Mirsada

    2010-02-01

    Pregnancy represents a risk factor in the occurrence of vaginal candidosis. The objectives of our study were: to make determination of the microscopic findings of vaginal swab, frequency of Candida species in the culture of pregnant women and patients who are not pregnant, determine the Candida species in all cultures, and to determine the frequency and differences in the frequency of C. albicans and other non-albicans species. In one year study performed during 2006 year, we tested patients of Gynaecology and Obstetrics clinic of the Clinical Centre in Sarajevo and Gynaecology department of the General hospital in Sarajevo. 447 woman included in the study were separated in two groups: 203 pregnant (in the last trimester of pregnancy), and 244 non-pregnant woman in period of fertility. Each vaginal swab was examined microscopically. The yeast, number of colonies, and the species of Candida were determined on Sabouraud dextrose agar with presence of antibiotics. For determination of Candida species, we used germ tube test for detection of C. albicans, and cultivation on the selective medium and assimilation tests for detection of non-albicans species. The results indicated positive microscopic findings in the test group (40,9%), as well as greater number of positive cultures (46,8%). The most commonly detected species for both groups was C. albicans ( test group 40.9% and control group 23,0%). The most commonly detected non-albicans species for the test group were C. glabrata (4,2 %) and C. krusei (3,2%), and for the control group were C. glabrata (3,2%) and C. parapsilosis (3,2%). The microscopic findings correlated with the number of colonies in positive cultures. In the test group, we found an increased number of yeasts (64,3%), and the pseudopyphae and blastopores by microscopic examination as an indication of infection. In the control group, we found a small number of yeasts (64,6%) , in the form of blastopores, as an indication of the candida colonisation. Our

  12. Detection of Candida albicans mRNA in Archival Histopathology Samples by Reverse Transcription-PCR

    PubMed Central

    Beggs, Kyle T.; Holmes, Ann R.; Cannon, Richard D.; Rich, Alison M.

    2004-01-01

    The feasibility of detecting Candida albicans mRNA in formalin-fixed paraffin-embedded archival human histopathology specimens by reverse transcription-PCR (RT-PCR) was investigated. RT with gene-specific primers was used to detect five single-copy C. albicans gene transcripts, including those of two housekeeping genes, in oral candidiasis samples up to 8 years of age. PMID:15131211

  13. Protective effect of picolinic acid on mice intracerebrally infected with lethal doses of Candida albicans.

    PubMed Central

    Blasi, E; Mazzolla, R; Pitzurra, L; Barluzzi, R; Bistoni, F

    1993-01-01

    We have studied the effects of picolinic acid (PLA), a product of tryptophan degradation, on mouse susceptibility to intracerebral infection with Candida albicans. We show that intraperitoneal administration of PLA significantly enhances the median survival time of mice inoculated with the lethal challenge. Furthermore, intracerebral administration of this agent induces a protective state against the local lethal infection, the phenomenon depending upon the administration schedule and doses of PLA employed. According to survival data, yeast growth in the brain as well as yeast colonization of the kidneys are drastically reduced in PLA-treated mice compared with those for untreated controls. Northern (RNA) blot analysis of brain tissues demonstrates that mRNA levels specific for tumor necrosis factor and interleukin 1 are augmented and induced, respectively, after inoculation of PLA. These results indicate that PLA has a protective effect likely involving elicitation of a cytokine response in vivo against fungal infections. Images PMID:7506894

  14. Solitary Candida albicans Infection Causing Fournier Gangrene and Review of Fungal Etiologies

    PubMed Central

    Perkins, Tiffany A; Bieniek, Jared M; Sumfest, Joel M

    2014-01-01

    Polymicrobial bacterial infections are commonly found in cases of Fournier gangrene (FG), although fungal growth may occur occasionally. Solitary fungal organisms causing FG have rarely been reported. The authors describe a case of an elderly man with a history of diabetes who presented with a necrotizing scrotal and perineal soft tissue infection. He underwent emergent surgical debridement with findings of diffuse urethral stricture disease and urinary extravasation requiring suprapubic tube placement. Candida albicans was found to be the single causative organism on culture, and the patient recovered well following antifungal treatment. Fungal infections should be considered as rare causes of necrotizing fasciitis and antifungal treatment considered in at-risk immunodeficient individuals. PMID:25009452

  15. Solitary Candida albicans Infection Causing Fournier Gangrene and Review of Fungal Etiologies.

    PubMed

    Perkins, Tiffany A; Bieniek, Jared M; Sumfest, Joel M

    2014-01-01

    Polymicrobial bacterial infections are commonly found in cases of Fournier gangrene (FG), although fungal growth may occur occasionally. Solitary fungal organisms causing FG have rarely been reported. The authors describe a case of an elderly man with a history of diabetes who presented with a necrotizing scrotal and perineal soft tissue infection. He underwent emergent surgical debridement with findings of diffuse urethral stricture disease and urinary extravasation requiring suprapubic tube placement. Candida albicans was found to be the single causative organism on culture, and the patient recovered well following antifungal treatment. Fungal infections should be considered as rare causes of necrotizing fasciitis and antifungal treatment considered in at-risk immunodeficient individuals. PMID:25009452

  16. The evaluation of β-(1 → 3)-nonaglucoside as an anti-Candida albicans immune response inducer.

    PubMed

    Paulovičová, Ema; Paulovičová, Lucia; Pilišiová, Ružena; Jančinová, Viera; Yashunsky, Dmitry V; Karelin, Alexander A; Tsvetkov, Yury E; Nifantiev, Nikolay E

    2016-09-01

    Synthetically prepared bovine serum albumin (BSA) conjugate of linear β-(1 → 3)-nonaglucoside ligand (G9) has been applied as a biological response immunomodulator in vivo and ex vivo. Active immunization of Balb/c mice revealed effective induction of specific humoral responses in comparison with Candida β-D-glucan and Candida whole cells. Induced post-vaccination serum exhibited a growth-inhibition effect on the multi-azole-resistant clinical strain Candida albicans CCY 29-3-164 in experimental mucocutaneous infection ex vivo. Evaluation of immune cell proliferation and the cytotoxic potential of the G9-ligand has revealed its bioavailability and an immunostimulative effect in vaccination-sensitized Balb/c mice splenocytes and RAW 264.7 macrophages. PMID:27310441

  17. The synthesis and synergistic antifungal effects of chalcones against drug resistant Candida albicans.

    PubMed

    Wang, Yuan-Hua; Dong, Huai-Huai; Zhao, Fei; Wang, Jie; Yan, Fang; Jiang, Yuan-Ying; Jin, Yong-Sheng

    2016-07-01

    To identify effective and low toxicity synergistic antifungal compounds, 24 derivatives of chalcone were synthesized to restore the effectiveness of fluconazole against fluconazole-resistant Candida albicans. The minimal inhibitory concentration (MIC80) and the fractional inhibitory concentration index (FICI) of the antifungal synergist fluconazole were measured against fluconazole-resistant Candida albicans. This was done via methods established by the clinical and laboratory standards institute (CLSI). Of the synthesized compounds, 2'-hydroxy-4'-methoxychalcone (8) exhibited the most potent in vitro (FICI=0.007) effects. The structure activity relationship of the compounds are then discussed. PMID:27210436

  18. Betamethasone augments the antifungal effect of menadione--towards a novel anti-Candida albicans combination therapy.

    PubMed

    Jakab, Ágnes; Emri, Tamás; Sipos, Lilla; Kiss, Ágnes; Kovács, Renátó; Dombrádi, Viktor; Kemény-Beke, Ádám; Balla, József; Majoros, László; Pócsi, István

    2015-08-01

    The fluorinated glucocorticoid betamethasone stimulated both the extracellular phospholipase production and hypha formation of the opportunistic human pathogen Candida albicans and also decreased the efficiency of the polyene antimycotics amphotericin B and nystatin against C. albicans in a dose-dependent manner. Importantly, betamethasone increased synergistically the anti-Candida activity of the oxidative stress generating agent menadione, which may be exploited in future combination therapies to prevent or cure C. albicans infections, in the field of dermatology.

  19. Cloning of the RHO1 gene from Candida albicans and its regulation of beta-1,3-glucan synthesis.

    PubMed Central

    Kondoh, O; Tachibana, Y; Ohya, Y; Arisawa, M; Watanabe, T

    1997-01-01

    The Saccharomyces cerevisiae RHO1 gene encodes a low-molecular-weight GTPase. One of its recently identified functions is the regulation of beta-1,3-glucan synthase, which synthesizes the main component of the fungal cell wall (J. Drgonova et al., Science 272:277-279, 1996; T. Mazur and W. Baginsky, J. Biol. Chem. 271:14604-14609, 1996; and H. Qadota et al., Science 272:279-281, 1996). From the opportunistic pathogenic fungus Candida albicans, we cloned the RHO1 gene by the PCR and cross-hybridization methods. Sequence analysis revealed that the Candida RHO1 gene has a 597-nucleotide region which encodes a putative 22.0-kDa peptide. The deduced amino acid sequence predicts that Candida albicans Rho1p is 82.9% identical to Saccharomyces Rho1p and contains all the domains conserved among Rho-type GTPases from other organisms. The Candida albicans RHO1 gene could rescue a S. cerevisiae strain containing a rho1 deletion. Furthermore, recombinant Candida albicans Rho1p could reactivate the beta-1,3-glucan synthesis activities of both C. albicans and S. cerevisiae membranes in which endogenous Rho1p had been depleted by Tergitol NP-40-NaCl treatment. Candida albicans Rho1p was copurified with the beta-1,3-glucan synthase putative catalytic subunit, Candida albicans Gsc1p, by product entrapment. Candida albicans Rho1p was shown to interact directly with Candida albicans Gsc1p in a ligand overlay assay and a cross-linking study. These results indicate that Candida albicans Rho1p acts in the same manner as Saccharomyces cerevisiae Rho1p to regulate beta-1,3-glucan synthesis. PMID:9401032

  20. Frequency, pathogenicity and microbiologic outcome of non-Candida albicans candiduria.

    PubMed

    Occhipinti, D J; Gubbins, P O; Schreckenberger, P; Danziger, L H

    1994-06-01

    A retrospective review of urine cultures obtained from patients at the University of Illinois Hospital revealed that the frequency of isolation of non-albicans Candida species increased significantly from 1990 to 1991 (p = 0.0003), while the frequency of isolation of Candida albicans species decreased significantly (p = 0.0006). Patients with urine cultures positive for non-albicans Candida species of Torulopsis glabrata during 1991 were identified for review. Sixty-seven patients were eligible for evaluation. Non-albicans candiduria developed in an average of 12 days. Identical fungal species were isolated from the blood following a positive urine culture in only two patients. Twenty patients were treated; candiduria persisted in 9 (45%), while resolution occurred in 11 (55%). The remaining 47 patients were not treated. Non-albicans candiduria persisted in 30 (64%) of these patients and resolved in 15 (32%); in the remaining two patients (4%) the microbiologic outcome was undetermined. The difference in microbiologic outcomes between treated and untreated patients was not significant using the Chi-square test (p = 0.170). Non-albicans candiduria developed rapidly, frequently persisted whether treated or untreated, and rarely progressed to candidemia.

  1. Systemic Staphylococcus aureus infection mediated by Candida albicans hyphal invasion of mucosal tissue

    PubMed Central

    Schlecht, Lisa Marie; Peters, Brian M.; Krom, Bastiaan P.; Freiberg, Jeffrey A.; Hänsch, Gertrud M.; Filler, Scott G.

    2015-01-01

    Candida albicans and Staphylococcus aureus are often co-isolated in cases of biofilm-associated infections. C. albicans can cause systemic disease through morphological switch from the rounded yeast to the invasive hyphal form. Alternatively, systemic S. aureus infections arise from seeding through breaks in host epithelial layers although many patients have no documented portal of entry. We describe a novel strategy by which S. aureus is able to invade host tissue and disseminate via adherence to the invasive hyphal elements of Candida albicans. In vitro and ex vivo findings demonstrate a specific binding of the staphylococci to the candida hyphal elements. The C. albicans cell wall adhesin Als3p binds to multiple staphylococcal adhesins. Furthermore, Als3p is required for C. albicans to transport S. aureus into the tissue and cause a disseminated infection in an oral co-colonization model. These findings suggest that C. albicans can facilitate the invasion of S. aureus across mucosal barriers, leading to systemic infection in co-colonized patients. PMID:25332378

  2. Study on the comparative activity of echinocandins on murine gut colonization by Candida albicans.

    PubMed

    Maraki, Sofia; Hamilos, George; Dimopoulou, Dimitra; Andrianaki, Angeliki M; Karageorgiadis, Alexander Steven; Kyvernitakis, Andreas; Lionakis, Stelios; Kofteridis, Diamantis P; Samonis, George

    2015-08-01

    Colonization of the gastrointestinal (GI) tract by Candida species is a principal pathogenetic event for development of invasive candidiasis. Importantly, the effect of echinocandins, the preferred antifungal agents for treatment of invasive candidiasis, on GI tract colonization by Candida spp. is currently unknown. Herein, we used an established model of persistent murine GI tract colonization by Candida albicans to test the ability of different echinocandins to eradicate the yeast from murine gut. Adult male Crl:CD1 (ICR) BR mice were fed with chow containing C. albicans and subsequently treated with different echinocandins or normal saline via daily intraperitoneal injections for 10 days. Quantitative stool cultures were performed immediately before (week one), and weekly for three months after discontinuation of treatment. Notably, treatment with all three echinocandins used (caspofungin, anidulafungin, and micafungin) resulted in eradication of Candida albicans from the stools, as evidenced by the significant reduction of yeast cells from a mean of 4.2 log10 CFU/g of stool before treatment (week one of colonization) to undetectable (<2 log10 CFU/g of stool) levels (week 12, P < 0.0001). In contrast, there was no significant reduction of Candida yeast cells in the stools of control mice. Collectively, the ability of echinocandins to eradicate C. albicans from the stools could have important implications in prophylaxis of high-risk patients for development of invasive candidiasis originating from the GI tract.

  3. Heterogeneous distribution of Candida albicans cell-surface antigens demonstrated with an Als1-specific monoclonal antibody

    PubMed Central

    Coleman, David A.; Oh, Soon-Hwan; Zhao, Xiaomin; Hoyer, Lois L.

    2010-01-01

    Despite an abundance of data describing expression of genes in the Candida albicans ALS (agglutinin-like sequence) gene family, little is known about the production of Als proteins on individual cells, their spatial localization or stability. Als proteins are most commonly discussed with respect to function in adhesion of C. albicans to host and abiotic surfaces. Development of a mAb specific for Als1, one of the eight large glycoproteins encoded by the ALS family, provided the opportunity to detect Als1 during growth of yeast and hyphae, both in vitro and in vivo, and to demonstrate the utility of the mAb in blocking C. albicans adhesion to host cells. Although most C. albicans yeast cells in a saturated culture are Als1-negative by indirect immunofluorescence, Als1 is detected on the surface of nearly all cells shortly after transfer into fresh growth medium. Als1 covers the yeast cell surface, with the exception of bud scars. Daughters of the inoculum cells, and sometimes granddaughters, also have detectable Als1, but Als1 is not detectable on cells from subsequent generations. On germ tubes and hyphae, most Als1 is localized proximal to the mother yeast. Once deposited on yeasts or hyphae, Als1 persists long after the culture has reached saturation. Growth stage-dependent production of Als1, coupled with its persistence on the cell surface, results in a heterogeneous population of cells within a C. albicans culture. Anti-Als1 immunolabelling patterns vary depending on the source of the C. albicans cells, with obvious differences between cells recovered from culture and those from a murine model of disseminated candidiasis. Results from this work highlight the temporal parallels for ALS1 expression and Als1 production in yeasts and germ tubes, the specialized spatial localization and persistence of Als1 on the C. albicans cell surface, and the differences in Als1 localization that occur in vitro and in vivo. PMID:20705663

  4. Comparative adherence of Candida albicans and Candida dubliniensis to human buccal epithelial cells and extracellular matrix proteins.

    PubMed

    Jordan, Rachael P C; Williams, David W; Moran, Gary P; Coleman, David C; Sullivan, Derek J

    2014-04-01

    Candida albicans and Candida dubliniensis are very closely related pathogenic yeast species. Despite their close relationship, C. albicans is a far more successful colonizer and pathogen of humans. The purpose of this study was to determine if the disparity in the virulence of the two species is attributed to differences in their ability to adhere to human buccal epithelial cells (BECs) and/or extracellular matrix proteins. When grown overnight at 30°C in yeast extract peptone dextrose, genotype 1 C. dubliniensis isolates were found to be significantly more adherent to human BECs than C. albicans or C. dubliniensis genotypes 2-4 (P < 0.001). However, when the yeast cells were grown at 37°C, no significant difference between the adhesion of C. dubliniensis genotype 1 and C. albicans to human BECs was observed, and C. dubliniensis genotype 1 and C. albicans adhered to BECs in significantly greater numbers than the other C. dubliniensis genotypes (P < 0.001). Using surface plasmon resonance analysis, C. dubliniensis isolates were found to adhere in significantly greater numbers than C. albicans to type I and IV collagen, fibronectin, laminin, vitronectin, and proline-rich peptides. These data suggest that C. albicans is not more adherent to epithelial cells or matrix proteins than C. dubliniensis and therefore other factors must contribute to the greater levels of virulence exhibited by C. albicans.

  5. Inhibitory Effect of Alpha-Mangostin on Adhesion of Candida albicans to Denture Acrylic

    PubMed Central

    Kaomongkolgit, Ruchadaporn; Jamdee, Kusuma

    2015-01-01

    Objective: Candida-associated denture stomatitis is a very common disease affecting denture wearers. It is characterized by the presence of yeast biofilm on the denture, primarily associated with C. albicans. The investigation of agents that can reduce C. albicans adhesion may represent a significant advancement in the prevention and treatment of this disease. This study aims to investigate the effect of alpha-mangostin on the in vitro adhesion of C. albicans to denture acrylic and germ tube formation by C. albicans and to compare its activity with clotrimazole which is a topical antifungal agent commonly used for the treatment of Candida-associated denture stomatitis. Materials and Methodology: Alpha-mangostin was extracted by thin layer chromatography. The effect of alpha-mangostin on adhesion of C. albicans to denture acrylic was determined by using a colorimetric tetrazolium assay and germ tube formation by C. albicans was determined by using the counting chamber. Results: A significant reduction of C. albicans adhesion to denture acrylic was evident after exposure to 2,000 µg/ml of alpha-mangostin for only 15 min. In addition, the 2,000 µg/ml of the alpha-mangostin-treated C. albicans had a reduced ability for germ tube formation. These inhibitory effects of alpha-mangostin were as effective as clotrimazole. Conclusion: Alpha-mangostin has antifungal property against C. albicans by inhibiting the adhesion to denture acrylic and germ tube formation in vitro. These results suggest the potential application of alpha-mangostin as a topical medication or a natural oral hygiene product for treatment of Candida-associated denture stomatitis. PMID:26962371

  6. Presumptive identification of Candida species other than C. albicans, C. krusei, and C. tropicalis with the chromogenic medium CHROMagar Candida

    PubMed Central

    Hospenthal, Duane R; Beckius, Miriam L; Floyd, Karon L; Horvath, Lynn L; Murray, Clinton K

    2006-01-01

    Background CHROMagar Candida (CaC) is increasingly being reported as a medium used to differentiate Candida albicans from non-albicans Candida (NAC) species. Rapid identification of NAC can assist the clinician in selecting appropriate antifungal therapy. CaC is a differential chromogenic medium designed to identify C. albicans, C. krusei, and C. tropicalis based on colony color and morphology. Some reports have proposed that CaC can also reliably identify C. dubliniensis and C. glabrata. Methods We evaluated the usefulness of CaC in the identification of C. dubliniensis, C. famata, C. firmetaria, C. glabrata, C. guilliermondii, C. inconspicua, C. kefyr, C. lipolytica, C. lusitaniae, C. norvegensis, C. parapsilosis, and C. rugosa. Results Most NAC produced colonies that were shades of pink, lavender, or ivory. Several isolates of C. firmetaria and all C. inconspicua produced colonies difficult to differentiate from C. krusei. Most C. rugosa isolates produced unique colonies with morphology like C. krusei except in a light blue-green color. C. glabrata isolates produced small dark violet colonies that could be differentiated from the pink and lavender colors produced by other species. All seventeen isolates of C. dubliniensis produced green colonies similar to those produced by C. albicans. Conclusion C. glabrata and C. rugosa appear distinguishable from other species using CaC. Some NAC, including C. firmetaria and C. inconspicua, could be confused with C. krusei using this medium. PMID:16390552

  7. External ecological niche for Candida albicans within reducing, oxygen-limited zones of wetlands.

    PubMed

    Stone, Wendy; Jones, Barbara-Lee; Wilsenach, Jac; Botha, Alfred

    2012-04-01

    Candida albicans within the human host is well studied; however, identifying environmental reservoirs of pathogens is epidemiologically valuable for disease management. Oxygen-limited, carbohydrate-rich zones of wetlands, to which sewage-borne C. albicans is often exposed, are characteristically similar to the gastrointestinal reservoir. Consequently, using quantitative real-time PCR (qRT-PCR) and gas chromatography-mass spectrometry (GC-MS), we demonstrated that oxygen-limited zones in polluted wetlands may act as potential reservoirs of C. albicans.

  8. Host defence against Candida albicans and the role of pattern-recognition receptors.

    PubMed

    Gauglitz, Gerd G; Callenberg, Helene; Weindl, Günther; Korting, Hans C

    2012-05-01

    Recognition of Candida albicans is mediated by several classes of pattern-recognition receptors, including Toll-like receptors and C-type lectin receptors. Cell wall components of C. albicans, interact with the pattern-recognition receptors, which are expressed by different cells, primarily antigen-presenting cells. This review aims to discuss the different pattern-recognition receptors responsible for recognition of special structures of C. albicans, which are known to activate intracellular signals that finally lead to directed and efficient host defence.

  9. A novel antifungal is active against Candida albicans biofilms and inhibits mutagenic acetaldehyde production in vitro.

    PubMed

    Nieminen, Mikko T; Novak-Frazer, Lily; Rautemaa, Vilma; Rajendran, Ranjith; Sorsa, Timo; Ramage, Gordon; Bowyer, Paul; Rautemaa, Riina

    2014-01-01

    The ability of C. albicans to form biofilms is a major virulence factor and a challenge for management. This is evident in biofilm-associated chronic oral-oesophageal candidosis, which has been shown to be potentially carcinogenic in vivo. We have previously shown that most Candida spp. can produce significant levels of mutagenic acetaldehyde (ACH). ACH is also an important mediator of candidal biofilm formation. We have also reported that D,L-2-hydroxyisocaproic acid (HICA) significantly inhibits planktonic growth of C. albicans. The aim of the present study was to investigate the effect of HICA on C. albicans biofilm formation and ACH production in vitro. Inhibition of biofilm formation by HICA, analogous control compounds or caspofungin was measured using XTT to measure biofilm metabolic activity and PicoGreen as a marker of biomass. Biofilms were visualised by scanning electron microscopy (SEM). ACH levels were measured by gas chromatography. Transcriptional changes in the genes involved in ACH metabolism were measured using RT-qPCR. The mean metabolic activity and biomass of all pre-grown (4, 24, 48 h) biofilms were significantly reduced after exposure to HICA (p<0.05) with the largest reductions seen at acidic pH. Caspofungin was mainly active against biofilms pre-grown for 4 h at neutral pH. Mutagenic levels (>40 µM) of ACH were detected in 24 and 48 h biofilms at both pHs. Interestingly, no ACH production was detected from D-glucose in the presence of HICA at acidic pH (p<0.05). Expression of genes responsible for ACH catabolism was up-regulated by HICA but down-regulated by caspofungin. SEM showed aberrant hyphae and collapsed hyphal structures during incubation with HICA at acidic pH. We conclude that HICA has potential as an antifungal agent with ability to inhibit C. albicans cell growth and biofilm formation. HICA also significantly reduces the mutagenic potential of C. albicans biofilms, which may be important when treating bacterial-fungal biofilm

  10. Antifungal mechanism of essential oil from Anethum graveolens seeds against Candida albicans.

    PubMed

    Chen, Yuxin; Zeng, Hong; Tian, Jun; Ban, Xiaoquan; Ma, Bingxin; Wang, Youwei

    2013-08-01

    This work studied the antifungal mechanism of dill seed essential oil (DSEO) against Candida albicans. Flow cytometric analysis and inhibition of ergosterol synthesis were performed to clarify the mechanism of action of DSEO on C. albicans. Upon treatment of cells with DSEO, propidium iodide penetrated C. albicans through a lesion in its plasma membrane. DSEO also significantly reduced the amount of ergosterol. These findings indicate that the plasma membrane of C. albicans was damaged by DSEO. The effect of DSEO on the functions of the mitochondria in C. albicans was also studied. We assayed the mitochondrial membrane potential (mtΔψ) using rhodamine 123 and determined the production of mitochondrial dysfunction-induced reactive oxygen species (ROS) via flow cytometry. The effects of the antioxidant l-cysteine (Cys) on DSEO-induced ROS production and the antifungal effect of DSEO on C. albicans were investigated. Exposure to DSEO increased mtΔψ. Dysfunctions in the mitochondria caused ROS accumulation in C. albicans. This increase in the level of ROS production and DSEO-induced decrease in cell viability were prevented by the addition of Cys, indicating that ROS are an important mediator of the antifungal action of DSEO. These findings indicate that the cytoplasmic membrane and mitochondria are the main anti-Candida targets of DSEO. PMID:23657528

  11. Micafungin triggers caspase-dependent apoptosis in Candida albicans and Candida parapsilosis biofilms, including caspofungin non-susceptible isolates.

    PubMed

    Shirazi, F; Kontoyiannis, D P

    2015-01-01

    Candida biofilms play an important role in infections associated with medical devices and are resistant to antifungals. We hypothesized that the echinocandin micafungin (MICA) exerts an enhanced antifungal activity against caspofungin (CAS)-susceptible (CAS-S) and CAS-non-susceptible (CAS-NS) Candida albicans and Candida parapsilosis which is at least in part through apoptosis, even in the biofilm environment. Apoptosis was characterized by detecting reactive oxygen species (ROS) accumulation, depolarization of mitochondrial membrane potential (MMP), DNA fragmentation, lack of plasma membrane integrity, and metacaspase activation following exposure of Candida biofilm to MICA for 3h at 37°C in RPMI 1640 medium. The minimum inhibitory concentration was higher for CAS (2.0-16.0 μg/mL) than for MICA (1.0-8.0 μg/mL) for Candida biofilms. Elevated intracellular ROS levels and depolarization of MMP was evident in CAS-S C. albicans (3.0-4.2 fold) and C. parapsilosis (4.8-5.4 fold) biofilms compared with CAS-NS (1.2 fold) after exposure to MICA (0.25x-1xMIC). Elevated intracellular ROS levels and depolarization of MMP was evident in CAS-S C. albicans (3.0-4.2 fold) and C. parapsilosis (4.8-5.4 fold) biofilms compared with CAS-NS (1.2 fold) after exposure to MICA (0.25x-1xMIC). Finally higher ß-1, 3 glucan levels were seen in sessile cells compared to planktonic cells, especially in CAS-NS strains. MICA treatment might induce a metacaspase-dependent apoptotic process in biofilms of both CAS-S C. albicans and C. parapsilosis, and to some degree in CAS-NS strains.

  12. Effect of Nitric Oxide on the Antifungal Activity of Oxidative Stress and Azoles Against Candida albicans.

    PubMed

    Li, De-Dong; Yang, Chang-Chun; Liu, Ping; Wang, Yan; Sun, Yan

    2016-06-01

    Nitric oxide (NO) is a small molecule with a wide range of biological activities in mammalian and bacteria. However, the role of NO in fungi, especially Candida albicans, is not clear. In this study, we confirmed the generation of endogenous NO in C. albicans, and found that the production of endogenous NO in C. albicans was associated with nitric oxide synthase pathway. Our results further indicated that the production of endogenous NO in C. albicans was reduced under oxidative stress such as menadione or H2O2 treatment. Meanwhile, exogenous NO donor, sodium nitroprusside (SNP), synergized with H2O2 against C. albicans. Interestingly, SNP could inhibit the antifungal effect of azoles against C. albicans in vitro, suggesting that NO might be involved in the resistance of C. albicans to antifungals. Collectively, this study demonstrated the production of endogenous NO in C. albicans, and indicated that NO may play an important role in the response of C. albicans to oxidative stress and azoles. PMID:27570314

  13. Human Epithelial Cells Discriminate between Commensal and Pathogenic Interactions with Candida albicans.

    PubMed

    Rast, Timothy J; Kullas, Amy L; Southern, Peter J; Davis, Dana A

    2016-01-01

    The commensal fungus, Candida albicans, can cause life-threatening infections in at risk individuals. C. albicans colonizes mucosal surfaces of most people, adhering to and interacting with epithelial cells. At low concentrations, C. albicans is not pathogenic nor does it cause epithelial cell damage in vitro; at high concentrations, C. albicans causes mucosal infections and kills epithelial cells in vitro. Here we show that while there are quantitative dose-dependent differences in exposed epithelial cell populations, these reflect a fundamental qualitative difference in host cell response to C. albicans. Using transcriptional profiling experiments and real time PCR, we found that wild-type C. albicans induce dose-dependent responses from a FaDu epithelial cell line. However, real time PCR and Western blot analysis using a high dose of various C. albicans strains demonstrated that these dose-dependent responses are associated with ability to promote host cell damage. Our studies support the idea that epithelial cells play a key role in the immune system by monitoring the microbial community at mucosal surfaces and initiating defensive responses when this community is dysfunctional. This places epithelial cells at a pivotal position in the interaction with C. albicans as epithelial cells themselves promote C. albicans stimulated damage.

  14. Antimicrobial blue light therapy for Candida albicans burn infection in mice

    NASA Astrophysics Data System (ADS)

    Zhang, Yunsong; Wang, Yucheng; Murray, Clinton K.; Hamblin, Michael R.; Gu, Ying; Dai, Tianhong

    2015-05-01

    In this preclinical study, we investigated the utility of antimicrobial blue light therapy for Candida albicans infection in acutely burned mice. A bioluminescent strain of C. albicans was used. The susceptibilities to blue light inactivation were compared between C. albicans and human keratinocyte. In vitro serial passaging of C. albicans on blue light exposure was performed to evaluate the potential development of resistance to blue light inactivation. A mouse model of acute thermal burn injury infected with the bioluminescent strain of C. albicans was developed. Blue light (415 nm) was delivered to mouse burns for decolonization of C. albicans. Bioluminescence imaging was used to monitor in real time the extent of fungal infection in mouse burns. Experimental results showed that C. albicans was approximately 42-fold more susceptible to blue light inactivation in vitro than human keratinocyte (P=0.0022). Serial passaging of C. albicans on blue light exposure implied a tendency for the fungal susceptibility to blue light inactivation to decrease with the numbers of passages. Blue light reduced fungal burden by over 4-log10 (99.99%) in acute mouse burns infected with C. albicans in comparison to infected mouse burns without blue light therapy (P=0.015).

  15. Gene expression profile of THP-1 cells treated with heat-killed Candida albicans

    PubMed Central

    Hu, Zhi-De; Wei, Ting-Ting; Tang, Qing-Qin; Ma, Ning; Wang, Li-Li; Qin, Bao-Dong; Yin, Jian-Rong

    2016-01-01

    Background Mechanisms under immune response against Candida albicans (C. albicans) remain largely unknown. To better understand the mechanisms of innate immune response against C. albicans, we analyzed the gene expression profile of THP-1 cells stimulated with heat-killed C. albicans. Methods THP-1 cells were stimulated with heat-killed C. albicans for 9 hours at a ratio of 1:1, and gene expression profile of the cells was analyzed using Whole Human Genome Oligo Microarray. Differentially expressed genes were defined as change folds more than 2 and with statistical significance. Gene ontology (GO) and pathway analysis were used to systematically identify biological connections of differentially expressed genes, as well as the pathways associated with the immune response against C. albicans. Results A total of 355 genes were up-regulated and 715 genes were down-regulated significantly. The up-regulated genes were particularly involved in biological process of RNA processing and pathway of the spliceosome. In case of down-regulated genes, the particularly involved immune-related pathways were G-protein coupled receptor signaling pathway, calcium signaling pathway, MAPK signaling pathway and Ras pathway. Conclusions We depict the gene expression profile of heat-killed C. albicans stimulated THP-1 cells, and identify the major pathways involved in immune response against C. albicans. These pathways are potential candidate targets for developing anti-C. albicans agent. PMID:27275483

  16. Human Epithelial Cells Discriminate between Commensal and Pathogenic Interactions with Candida albicans

    PubMed Central

    Rast, Timothy J.; Kullas, Amy L.; Southern, Peter J.; Davis, Dana A.

    2016-01-01

    The commensal fungus, Candida albicans, can cause life-threatening infections in at risk individuals. C. albicans colonizes mucosal surfaces of most people, adhering to and interacting with epithelial cells. At low concentrations, C. albicans is not pathogenic nor does it cause epithelial cell damage in vitro; at high concentrations, C. albicans causes mucosal infections and kills epithelial cells in vitro. Here we show that while there are quantitative dose-dependent differences in exposed epithelial cell populations, these reflect a fundamental qualitative difference in host cell response to C. albicans. Using transcriptional profiling experiments and real time PCR, we found that wild-type C. albicans induce dose-dependent responses from a FaDu epithelial cell line. However, real time PCR and Western blot analysis using a high dose of various C. albicans strains demonstrated that these dose-dependent responses are associated with ability to promote host cell damage. Our studies support the idea that epithelial cells play a key role in the immune system by monitoring the microbial community at mucosal surfaces and initiating defensive responses when this community is dysfunctional. This places epithelial cells at a pivotal position in the interaction with C. albicans as epithelial cells themselves promote C. albicans stimulated damage. PMID:27088599

  17. Liposomal thymoquinone effectively combats fluconazole-resistant Candida albicans in a murine model.

    PubMed

    Khan, Masood Alam; Aljarbou, Ahmad N; Khan, Arif; Younus, Hina

    2015-05-01

    The aim of the present study was to develop a novel liposomal formulation of thymoquinone (TQ) to treat fluconazole-susceptible and -resistant Candida albicans (C. albicans) infections. The liposomal preparation of TQ (Lip-TQ) was used against a fluconazole-susceptible or -resistant isolate of C. albicans. Various doses of fluconazole (0, 5, 10, 20 and 40 mg/kg) or free TQ or Lip-TQ (0, 1, 2 and 5mg/kg) were used to treat C. albicans infected mice. Mice were observed for 40 days post C. albicans infection, and their kidneys were assessed for the fungal load. Fluconazole showed anti-fungal activity against the drug-susceptible, but not against the -resistant isolate of C. albicans. Free TQ showed its activity against both fluconazole-susceptible or -resistant C. albicans, however, Lip-TQ was found to be the most effective and imparted ∼ 100% and ∼ 90% survival of mice infected with fluconazole-susceptible and -resistant isolates of C. albicans, respectively. Mice treated with Lip-TQ showed highly reduced severity of infection in their tissue homogenates. Therefore, Lip-TQ may effectively be used in the treatment of C. albicans infections, including those which are not responding to fluconazole.

  18. Human Epithelial Cells Discriminate between Commensal and Pathogenic Interactions with Candida albicans.

    PubMed

    Rast, Timothy J; Kullas, Amy L; Southern, Peter J; Davis, Dana A

    2016-01-01

    The commensal fungus, Candida albicans, can cause life-threatening infections in at risk individuals. C. albicans colonizes mucosal surfaces of most people, adhering to and interacting with epithelial cells. At low concentrations, C. albicans is not pathogenic nor does it cause epithelial cell damage in vitro; at high concentrations, C. albicans causes mucosal infections and kills epithelial cells in vitro. Here we show that while there are quantitative dose-dependent differences in exposed epithelial cell populations, these reflect a fundamental qualitative difference in host cell response to C. albicans. Using transcriptional profiling experiments and real time PCR, we found that wild-type C. albicans induce dose-dependent responses from a FaDu epithelial cell line. However, real time PCR and Western blot analysis using a high dose of various C. albicans strains demonstrated that these dose-dependent responses are associated with ability to promote host cell damage. Our studies support the idea that epithelial cells play a key role in the immune system by monitoring the microbial community at mucosal surfaces and initiating defensive responses when this community is dysfunctional. This places epithelial cells at a pivotal position in the interaction with C. albicans as epithelial cells themselves promote C. albicans stimulated damage. PMID:27088599

  19. Association of KPC-producing Klebsiella pneumoniae colonization or infection with Candida isolation and selection of non-albicans species.

    PubMed

    Papadimitriou-Olivgeris, Matthaios; Spiliopoulou, Anastasia; Fligou, Fotini; Manolopoulou, Patroula; Spiliopoulou, Iris; Vrettos, Theofanis; Dodou, Vasiliki; Filos, Kriton S; Anastassiou, Evangelos D; Marangos, Markos; Christofidou, Myrto

    2014-11-01

    Clinical specimens from 565 patients hospitalized in 2 intensive care units (ICUs A and B) during a 28-month period were cultured on appropriate media for isolation of Candida. Forty-nine (9%) patients had at least a Candida spp.-positive sample. Candida albicans was the predominant species isolated from 26 (53%) patients. Seventeen patients (3%) developed candidemia. Multivariate analysis showed that obesity, female gender, hospitalization during summer months, admission at ICU B, parenteral nutrition, administration of metronidazole, transplantation, and KPC-producing Klebsiella pneumoniae (KPC-Kp) infection were independently associated with Candida spp. isolation. Candidemia was associated with cortisone administration, KPC-Kp infection, and presence of colostomy or abdominal catheter. Administration of fluconazole was a protective factor for both Candida spp. isolation and infection, leading to selection of Candida non-albicans species. Among several risk factors, KPC-Kp infection and colonization are identified as statistically significant factors associated with Candida isolation, especially of non-albicans species.

  20. Ras pathway signaling accelerates programmed cell death in the pathogenic fungus Candida albicans.

    PubMed

    Phillips, Andrew J; Crowe, Jonathan D; Ramsdale, Mark

    2006-01-17

    A better understanding of the molecular basis of programmed cell death (PCD) in fungi could provide information that is useful in the design of antifungal drugs that combat life-threatening fungal infections. Harsh environmental stresses, such as acetic acid or hydrogen peroxide, have been shown to induce PCD in the pathogenic fungus Candida albicans. In this study, we show that dying cells progress from an apoptotic state to a secondary necrotic state and that the rate at which this change occurs is proportional to the intensity of the stimulus. Also, we found that the temporal response is modulated by Ras-cAMP-PKA signals. Mutations that block Ras-cAMP-PKA signaling (ras1Delta, cdc35Delta, tpk1Delta, and tpk2Delta) suppress or delay the apoptotic response, whereas mutations that stimulate signaling (RAS1(val13) and pde2Delta) accelerate the rate of entry of cells into apoptosis. Pharmacological stimulation or inhibition of Ras signaling reinforces these findings. Transient increases in endogenous cAMP occur under conditions that stimulate apoptosis but not growth arrest. Death-specific changes in the abundance of different isoforms of the PKA regulatory subunit, Bcy1p, are also observed. Activation of Ras signals may regulate PCD of C. albicans, either by inhibiting antiapoptotic functions (such as stress responses) or by activating proapoptotic functions. PMID:16407097

  1. Positive interaction of thyme (red) essential oil with human polymorphonuclear granulocytes in eradicating intracellular Candida albicans.

    PubMed

    Tullio, Vivian; Mandras, Narcisa; Allizond, Valeria; Nostro, Antonia; Roana, Janira; Merlino, Chiara; Banche, Giuliana; Scalas, Daniela; Cuffini, Anna Maria

    2012-10-01

    The essential oils have started to be recognized for their potential antimicrobial role only in recent years. Clinical experience showed that the efficacy of antimicrobial agents depends not only on their direct effect on a given microorganism but also on the functional activity of the host immune system. Since data on the effects of essential oils on the innate immune system are scanty and fragmentary, the aim of this study was to evaluate the influence of thyme (red) essential oil (EO), at subinhibitory/inhibitory concentrations, on intracellular killing activity by human polymorphonuclear granulocytes (PMNs) against Candida albicans. In order to provide a frame of reference for the activity of this EO, its in vitro killing activity in the absence of PMNs was also evaluated.Results showed that EO at subminimal inhibitory (subMIC)/minimal inhibitory (MIC) concentrations significantly enhanced intracellular killing of C. albicans in comparison with EO-free controls and was comparable to the positive control (fluconazole). In in vitro killing assays without PMNs, we observed progressive growth of the yeast cells in the presence of EO subMIC/MIC concentrations. A positive antifungal interaction with phagocytes could explain why this EO, which appeared to be only fungistatic in time-kill assays, had efficacy in killing yeast cells once incubated with PMNs. PMID:22872591

  2. Click beetle luciferases as dual reporters of gene expression in Candida albicans.

    PubMed

    Kapitan, Mario; Eichhof, Isabel; Lagadec, Quentin; Ernst, Joachim F

    2016-08-01

    Synthetic genes encoding functional luciferases of the click beetle (CB) Pyrophorus plagiophthalamus have been expressed in the human fungal pathogen Candida albicans. Both green- and red-emitting CB luciferases (CaCBGluc and CaCBRluc) were produced with high efficiency in transformants under transcriptional control of the growth-dependent ACT1 promoter, as well as by the HWP1 and UME6 promoters, which are upregulated during hyphal morphogenesis, as well as by the YWP1 and EFG1 promoters, which are downregulated. For all hyphally regulated genes, relative bioluminescence values derived from promoter fusions approximated relative transcript levels of native genes, although downregulation of YWP1 promoter activity required correction for the stability of CB luciferases (approximate half-lives 30 min for CaCBRluc and 80 min for CaCBGluc, as determined by immunoblotting). Importantly, the activity of both luciferases could be separately monitored in a single strain, in intact cells, in lysed cells or in cell extracts using luciferin as single substrate and inhibition of hypha formation by farnesol could be easily detected by the HWP1p-CaCBRluc fusion. The results suggest that CB luciferases are convenient tools to measure gene expression in C. albicans and may facilitate screenings for antifungal compounds. PMID:27339610

  3. Efficacy of 1% sodium fluoride as a preservative in urine samples containing glucose and Candida albicans.

    PubMed

    Lough, P S; Fehn, R

    1993-03-01

    Whether urine samples used in forensic science DUI testing can be compromised by endogenous ethanol production is a recurrent and yet unresolved issue. This study first assessed unpreserved urine samples that were collected, processed, and analyzed repeatedly over 13 to 41 days using a standard gas chromatographic procedure for ethanol analysis. Despite extensive microbial growth, ethanol was not detected in any test sample. The extent of ethanol production in samples supplemented with glucose, Candida albicans, or both was determined to evaluate the potential for ethanol production in urine samples associated with pathological conditions such as urinary tract yeast infections and diabetes mellitus. Ethanol production under each of the above treatment conditions was assessed in the presence and absence of 1% sodium fluoride as a microbial suppressant. Mean ethanol concentrations were determined for unpreserved samples containing urine only (0.003 +/- 0.005 g%), urine plus yeast (0.006 +/- 0.009 g%) and urine plus glucose (0.067 +/- 0.070 g%). Unpreserved samples supplemented with both yeast and glucose attained mean ethanol concentrations of 0.164 +/- 0.057 g% (P < 0.01). Ethanol could not be detected in any corresponding duplicate samples, which were preserved with 1% sodium fluoride. A lack of ethanol production in any of the unpreserved urine samples indicates that false DUI convictions due to endogenous ethanol production are very unlikely. And while endogenous ethanol production is possible in the presence of both glucose and contaminating C. albicans, 1% sodium fluoride completely eliminated microbial fermentation.

  4. Differential effects of antifungal agents on expression of genes related to formation of Candida albicans biofilms.

    PubMed

    Chatzimoschou, Athanasios; Simitsopoulou, Maria; Antachopoulos, Charalampos; Walsh, Thomas J; Roilides, Emmanuel

    2016-01-01

    The purpose of this study was to analyse specific molecular mechanisms involved in the intrinsic resistance of C. albicans biofilms to antifungals. We investigated the transcriptional profile of three genes (BGL2, SUN41, ECE1) involved in Candida cell wall formation in response to voriconazole or anidulafungin after the production of intermediate and mature biofilms. C. albicans M61, a well-documented biofilm producer strain, was used for the development of intermediate (12 h and 18 h) and completely mature biofilms (48 h). After exposure of cells from each biofilm growth mode to voriconazole (128 and 512 mg l(-1)) or anidulafungin (0.25 and 1 mg l(-1)) for 12-24 h, total RNA samples extracted from biofilm cells were analysed by RT-PCR. The voriconazole and anidulafungin biofilm MIC was 512 and 0.5 mg l(-1) respectively. Anidulafungin caused significant up-regulation of SUN41 (3.7-9.3-fold) and BGL2 (2.2-2.8 fold) in intermediately mature biofilms; whereas, voriconazole increased gene expression in completely mature biofilms (SUN41 2.3-fold, BGL2 2.1-fold). Gene expression was primarily down-regulated by voriconazole in intermediately, but not completely mature biofilms. Both antifungals caused down-regulation of ECE1 in intermediately mature biofilms.

  5. The Candida albicans Kar2 protein is essential and functions during the translocation of proteins into the endoplasmic reticulum

    PubMed Central

    Janke, Megan R.; Lund, Kyle; Morrison, Emily P.; Paulson, Benjamin A.

    2012-01-01

    Since the secretory pathway is essential for Candida albicans to transition from a commensal organism to a pathogen, an understanding of how this pathway functions may be beneficial for identifying novel drug targets to prevent candidiasis. We have cloned the C. albicans KAR2 gene, which performs many roles during the translocation of proteins into the endoplasmic reticulum (ER) during the first committed step of the secretory pathway in many eukaryotes. Our results show that C. albicans KAR2 is essential, and that the encoded protein rescues a temperature-sensitive growth defect found in a Saccharomyces cerevisiae strain harboring a mutant form of the Kar2 protein. Additionally, S. cerevisiae containing CaKAR2 as the sole copy of this essential gene are viable, and ER microsomes prepared from this strain exhibit wild-type levels of post-translational translocation during in vitro translocation assays. Finally, ER microsomes isolated from a C. albicans strain expressing reduced amounts of KAR2 mRNA are defective for in vitro translocation of a secreted substrate protein, establishing a new method to study ER translocation in this organism. Together, these results suggest that C. albicans Kar2p functions during the translocation of proteins into the ER during the first step of the secretory pathway. PMID:20886215

  6. Altered hepatic clearance and killing of Candida albicans in the isolated perfused mouse liver model.

    PubMed

    Sawyer, R T; Horst, M N; Garner, R E; Hudson, J; Jenkins, P R; Richardson, A L

    1990-09-01

    The adherence of Candida albicans was studied in situ by using the perfused mouse liver model. After exhaustive washing, 10(6) C. albicans were infused into mouse livers. At the time of recovery, 62 +/- 5% (mean +/- standard error of the mean) of the infused C. albicans were recovered from the liver and 14 +/- 3% were recovered from the effluent for a total recovery of 76 +/- 4%. This indicates that 86 +/- 3% of the original inoculum was trapped by the liver and that 24 +/- 4% was killed within the liver. Chemical pretreatment of C. albicans with 8 M urea, 12 mM dithiothreitol, 2% beta-mercaptoethanol, 1% sodium dodecyl sulfate, 10% Triton X-100, or 3 M potassium chloride or enzyme pretreatment with alpha-mannosidase, alpha-chymotrypsin, subtilisin, beta-N-acetyl-glucosaminidase, pronase, trypsin, papain, or lipase did not alter adherence of C. albicans to hepatic tissue. By contrast, pepsin pretreatment significantly decreased hepatic trapping. Simultaneous perfusion with either 100 mg of C. albicans glycoprotein per liter or 100 mg of C. albicans mannan per liter also decreased trapping. Furthermore, both substances eluted previously trapped C. albicans from hepatic tissue. Chemical pretreatment with 8 M urea, 12 mM dithiothreitol, or 3 M KCI or enzymatic pretreatment with alpha-mannosidase, subtilisin, alpha-chymotrypsin, or papain increased killing of C. albicans three- to fivefold within hepatic tissue. The data suggest that mannose-containing structures on the surface of C. albicans, for example. mannans or glucomannoproteins, mediate adherence of C. albicans within the liver. Indirectly, chemical and enzymatic pretreatment renders C. albicans more susceptible to hepatic killing.

  7. Candida albicans Shaving to Profile Human Serum Proteins on Hyphal Surface

    PubMed Central

    Marín, Elvira; Parra-Giraldo, Claudia M.; Hernández-Haro, Carolina; Hernáez, María L.; Nombela, César; Monteoliva, Lucía; Gil, Concha

    2015-01-01

    Candida albicans is a human opportunistic fungus and it is responsible for a wide variety of infections, either superficial or systemic. C. albicans is a polymorphic fungus and its ability to switch between yeast and hyphae is essential for its virulence. Once C. albicans obtains access to the human body, the host serum constitutes a complex environment of interaction with C. albicans cell surface in bloodstream. To draw a comprehensive picture of this relevant step in host-pathogen interaction during invasive candidiasis, we have optimized a gel-free shaving proteomic strategy to identify both, human serum proteins coating C. albicans cells and fungi surface proteins simultaneously. This approach was carried out with normal serum (NS) and heat inactivated serum (HIS). We identified 214 human and 372 C. albicans unique proteins. Proteins identified in C. albicans included 147 which were described as located at the cell surface and 52 that were described as immunogenic. Interestingly, among these C. albicans proteins, we identified 23 GPI-anchored proteins, Gpd2 and Pra1, which are involved in complement system evasion and 7 other proteins that are able to attach plasminogen to C. albicans surface (Adh1, Eno1, Fba1, Pgk1, Tdh3, Tef1, and Tsa1). Furthermore, 12 proteins identified at the C. albicans hyphae surface induced with 10% human serum were not detected in other hypha-induced conditions. The most abundant human proteins identified are involved in complement and coagulation pathways. Remarkably, with this strategy, all main proteins belonging to complement cascades were identified on the C. albicans surface. Moreover, we identified immunoglobulins, cytoskeletal proteins, metabolic proteins such as apolipoproteins and others. Additionally, we identified more inhibitors of complement and coagulation pathways, some of them serpin proteins (serine protease inhibitors), in HIS vs. NS. On the other hand, we detected a higher amount of C3 at the C. albicans surface in

  8. A single strain of Candida albicans associated with separate episodes of fungemia and meningitis.

    PubMed Central

    Porter, S D; Noble, M A; Rennie, R

    1996-01-01

    Four isolates of Candida albicans recovered from the blood and cerebral spinal fluid of a 66-year-old man during episodes of systemic infection separated by 3 months and antifungal therapy were analyzed by a variety of molecular typing methods. All four isolates were shown to represent the same strain, indicating a relapse of infection rather than reinfection. PMID:8784598

  9. Cerebral macroabscess caused by Candida albicans in an immunocompetent patient: A diagnostic challenge

    PubMed Central

    Figueiredo, Sônia M.; Campolina, Sabrina; Rosa, Carlos A.; Gontijo, Marcus; Tirone, Thelma; Assunção, Claudia B.; Freire, Tarcísio F.A.; Christo, Paulo P.; Caligiorne, Rachel B.

    2014-01-01

    We describe the history of a 24-year-old immunocompetent man with an expansive lesion in the brainstem that, after many misdiagnoses, was found to be caused by a Candida albicans abscess. One year after surgery and 3 months of fluconazole treatment, the patient was asymptomatic and all image and laboratory tests were normal. PMID:24567895

  10. Comparative Susceptibility of Candida albicans to Amphotericin B and Amphotericin B Methyl Ester

    PubMed Central

    Bannatyne, Robert M.; Cheung, Rose

    1977-01-01

    The in vitro antifungal activities of amphotericin B (AMB) and amphotericin B methyl ester (AME) were compared against 465 clinical isolates of Candida albicans. AMB and AME possessed comparable activity against half of the strains, but against the remainder of the strains the activity of AME was slightly lower than that of AMB. Rarely did AME show superior antifungal activity to AMB. PMID:335958

  11. Microevolution of Candida albicans in macrophages restores filamentation in a nonfilamentous mutant.

    PubMed

    Wartenberg, Anja; Linde, Jörg; Martin, Ronny; Schreiner, Maria; Horn, Fabian; Jacobsen, Ilse D; Jenull, Sabrina; Wolf, Thomas; Kuchler, Karl; Guthke, Reinhard; Kurzai, Oliver; Forche, Anja; d'Enfert, Christophe; Brunke, Sascha; Hube, Bernhard

    2014-12-01

    Following antifungal treatment, Candida albicans, and other human pathogenic fungi can undergo microevolution, which leads to the emergence of drug resistance. However, the capacity for microevolutionary adaptation of fungi goes beyond the development of resistance against antifungals. Here we used an experimental microevolution approach to show that one of the central pathogenicity mechanisms of C. albicans, the yeast-to-hyphae transition, can be subject to experimental evolution. The C. albicans cph1Δ/efg1Δ mutant is nonfilamentous, as central signaling pathways linking environmental cues to hyphal formation are disrupted. We subjected this mutant to constant selection pressure in the hostile environment of the macrophage phagosome. In a comparatively short time-frame, the mutant evolved the ability to escape macrophages by filamentation. In addition, the evolved mutant exhibited hyper-virulence in a murine infection model and an altered cell wall composition compared to the cph1Δ/efg1Δ strain. Moreover, the transcriptional regulation of hyphae-associated, and other pathogenicity-related genes became re-responsive to environmental cues in the evolved strain. We went on to identify the causative missense mutation via whole genome- and transcriptome-sequencing: a single nucleotide exchange took place within SSN3 that encodes a component of the Cdk8 module of the Mediator complex, which links transcription factors with the general transcription machinery. This mutation was responsible for the reconnection of the hyphal growth program with environmental signals in the evolved strain and was sufficient to bypass Efg1/Cph1-dependent filamentation. These data demonstrate that even central transcriptional networks can be remodeled very quickly under appropriate selection pressure. PMID:25474009

  12. Production of tyrosol by Candida albicans biofilms and its role in quorum sensing and biofilm development.

    PubMed

    Alem, Mohammed A S; Oteef, Mohammed D Y; Flowers, T Hugh; Douglas, L Julia

    2006-10-01

    Tyrosol and farnesol are quorum-sensing molecules produced by Candida albicans which accelerate and block, respectively, the morphological transition from yeasts to hyphae. In this study, we have investigated the secretion of tyrosol by C. albicans and explored its likely role in biofilm development. Both planktonic (suspended) cells and biofilms of four C. albicans strains, including three mutants with defined defects in the Efg 1 and Cph 1 morphogenetic signaling pathways, synthesized extracellular tyrosol during growth at 37 degrees C. There was a correlation between tyrosol production and biomass for both cell types. However, biofilm cells secreted at least 50% more tyrosol than did planktonic cells when tyrosol production was related to cell dry weight. The addition of exogenous farnesol to a wild-type strain inhibited biofilm formation by up to 33% after 48 h. Exogenous tyrosol appeared to have no effect, but scanning electron microscopy revealed that tyrosol stimulated hypha production during the early stages (1 to 6 h) of biofilm development. Experiments involving the simultaneous addition of tyrosol and farnesol at different concentrations suggested that the action of farnesol was dominant, and 48-h biofilms formed in the presence of both compounds consisted almost entirely of yeast cells. When biofilm supernatants were tested for their abilities to inhibit or enhance germ tube formation by planktonic cells, the results indicated that tyrosol activity exceeds that of farnesol after 14 h, but not after 24 h, and that farnesol activity increases significantly during the later stages (48 to 72 h) of biofilm development. Overall, our results support the conclusion that tyrosol acts as a quorum-sensing molecule for biofilms as well as for planktonic cells and that its action is most significant during the early and intermediate stages of biofilm formation. PMID:16980403

  13. Tetracycline alters drug susceptibility in Candida albicans and other pathogenic fungi

    PubMed Central

    Oliver, Brian G.; Silver, Peter M.; Marie, Chelsea; Hoot, Samantha J.; Leyde, Sarah E.; White, Theodore C.

    2008-01-01

    Summary The tetracycline (TET) promoter has been used in several systems as an inducible regulator of gene expression. In control analyses, the standard Candida albicans laboratory strain SC5314 was found to have altered susceptibility to a variety of antifungal drugs in the presence of relatively high concentrations (50 to 200 μg/ml) of TET. Altered susceptibility was most notable with exposure to amphotericin B (AMB) with a 32 fold increase in susceptibility, and terbinafine (TRB) with a 32 fold decrease in susceptibility. The TET/AMB synergy was observed in several clinical isolates of C. albicans and in distantly related species Aspergillus fumigatus, and Cryptococcus neoformans. The TET/AMB synergy is not related to efflux pump activity, as determined by FACS analyses and by analysis of a strain containing efflux pump deletions. Gene expression analyses by luciferase and by quantitative real time reverse transcriptase PCR failed to identify significant alterations in expression of any genes associated with resistance. C. albicans grown in TET for 48 h does show a reduction in total cellular ergosterol. Analysis of growth curves suggests that the TET effect is associated with lack of a diauxic shift, which is related to a loss of mitochondrial function. MitoTracker fluorescent dye was used to demonstrate that TET has a direct effect on mitochondrial function. These results demonstrate the need for careful analysis of TET effects when using a TET-inducible promoter, especially in studies that involve antifungal drugs. This study defines some limits to the use of the TET inducible promoter, and identifies effects on cells that are the result of TET exposure alone, not the result of expression of a targeted gene. PMID:18310042

  14. pH Regulates White-Opaque Switching and Sexual Mating in Candida albicans.

    PubMed

    Sun, Yuan; Cao, Chengjun; Jia, Wei; Tao, Li; Guan, Guobo; Huang, Guanghua

    2015-11-01

    As a successful commensal and pathogen of humans, Candida albicans encounters a wide range of environmental conditions. Among them, ambient pH, which changes frequently and affects many biological processes in this species, is an important factor, and the ability to adapt to pH changes is tightly linked with pathogenesis and morphogenesis. In this study, we report that pH has a profound effect on white-opaque switching and sexual mating in C. albicans. Acidic pH promotes white-to-opaque switching under certain culture conditions but represses sexual mating. The Rim101-mediated pH-sensing pathway is involved in the control of pH-regulated white-opaque switching and the mating response. Phr2 and Rim101 could play a major role in acidic pH-induced opaque cell formation. Despite the fact that the cyclic AMP (cAMP) signaling pathway does not play a major role in pH-regulated white-opaque switching and mating, white and opaque cells of the cyr1/cyr1 mutant, which is defective in the production of cAMP, showed distinct growth defects under acidic and alkaline conditions. We further discovered that acidic pH conditions repressed sexual mating due to the failure of activation of the Ste2-mediated α-pheromone response pathway in opaque A: cells. The effects of pH changes on phenotypic switching and sexual mating could involve a balance of host adaptation and sexual reproduction in C. albicans.

  15. The Candida albicans ATO Gene Family Promotes Neutralization of the Macrophage Phagolysosome

    PubMed Central

    Danhof, Heather A.

    2015-01-01

    Candida albicans is an opportunistic human fungal pathogen that causes a variety of diseases, ranging from superficial mucosal to life-threatening systemic infections, the latter particularly in patients with defects in innate immune function. C. albicans cells phagocytosed by macrophages undergo a dramatic change in their metabolism in which amino acids are a key nutrient. We have shown that amino acid catabolism allows the cell to neutralize the phagolysosome and initiate hyphal growth. We show here that members of the 10-gene ATO family, which are induced by phagocytosis or the presence of amino acids in an Stp2-dependent manner and encode putative acetate or ammonia transporters, are important effectors of this pH change in vitro and in macrophages. When grown with amino acids as the sole carbon source, the deletion of ATO5 or the expression of a dominant-negative ATO1G53D allele results in a delay in alkalinization, a defect in hyphal formation, and a reduction in the amount of ammonia released from the cell. These strains also form fewer hyphae after phagocytosis, have a reduced ability to escape macrophages, and reside in more acidic phagolysosomal compartments than wild-type cells. Furthermore, overexpression of many of the 10 ATO genes accelerates ammonia release, and an ato5Δ ATO1G53D double mutant strain has additive alkalinization and ammonia release defects. Taken together, these results indicate that the Ato protein family is a key mediator of the metabolic changes that allow C. albicans to overcome the macrophage innate immunity barrier. PMID:26351284

  16. Effect of surface treatments of porcelain on adhesion of Candida albicans.

    PubMed

    Lawaf, Shirin; Azizi, Arash; Farzad, Azin; Adimi, Parvaneh

    2016-01-01

    Surface treatment of porcelain is required to minimize the adhesion of microorganisms to surfaces of the restoration. This study sought to assess the effects of 3 different porcelain surface treatments on adhesion of Candida albicans. This in vitro experimental study was conducted on 60 porcelain disks (10 × 3 mm) randomly divided into 4 groups of 15. The nonglazed group received no surface treatment; specimens in the other 3 groups were glazed in the furnace, overglazed with liquid glaze, or polished using a polishing kit. The specimens were washed, sterilized, and separately incubated with 350 µL of Candida albicans suspension for 24 hours. Specimens were then rinsed for 20 seconds and shaken in 1 mL of saline solution for 1 minute, and 20 µL of this suspension was cultured in a plate and incubated at 37°C for 48 hours. Candida albicans colonies were counted to assess the number of microorganisms adhering to each disk. Data were analyzed with the Kruskal-Wallis test. Statistically significant differences were found among the 4 groups in terms of C albicans adherence (P = 0.001). The nonglazed porcelain had the highest and the overglazed porcelain had the lowest mean adherence value. No statistically significant difference was noted between glazed and polished specimens. Based on the obtained results, overglazing resulted in the least adhesion of C albicans, and polishing provided a surface as smooth as a glazed surface. PMID:27367639

  17. Virulence and pathogenicity of Candida albicans is enhanced in biofilms containing oral bacteria.

    PubMed

    Cavalcanti, Yuri Wanderley; Morse, Daniel James; da Silva, Wander José; Del-Bel-Cury, Altair Antoninha; Wei, Xiaoqing; Wilson, Melanie; Milward, Paul; Lewis, Michael; Bradshaw, David; Williams, David Wynne

    2015-01-01

    This study examined the influence of bacteria on the virulence and pathogenicity of candidal biofilms. Mature biofilms (Candida albicans-only, bacteria-only, C. albicans with bacteria) were generated on acrylic and either analysed directly, or used to infect a reconstituted human oral epithelium (RHOE). Analyses included Candida hyphae enumeration and assessment of Candida virulence gene expression. Lactate dehydrogenase (LDH) activity and Candida tissue invasion following biofilm infection of the RHOE were also measured. Candida hyphae were more prevalent (p < 0.05) in acrylic biofilms also containing bacteria, with genes encoding secreted aspartyl-proteinases (SAP4/SAP6) and hyphal-wall protein (HWP1) up-regulated (p < 0.05). Candida adhesin genes (ALS3/EPA1), SAP6 and HWP1 were up-regulated in mixed-species biofilm infections of RHOE. Multi-species infections exhibited higher hyphal proportions (p < 0.05), up-regulation of IL-18, higher LDH activity and tissue invasion. As the presence of bacteria in acrylic biofilms promoted Candida virulence, consideration should be given to the bacterial component when managing denture biofilm associated candidoses.

  18. Demonstration of synergy with fluconazole and either ibuprofen, sodium salicylate, or propylparaben against Candida albicans in vitro.

    PubMed Central

    Scott, E M; Tariq, V N; McCrory, R M

    1995-01-01

    The combination of fluconazole with either ibuprofen, sodium salicylate, or propylparaben resulted in synergistic activity (fractional inhibitory index, < 0.5) against Candida albicans NCYC 620 in a microdilution checkerboard assay. Synergism between miconazole and ibuprofen was also demonstrated. In three or four clinical isolates of C. albicans from AIDS patients, the combination of fluconazole and ibuprofen was synergistic. Preparation of the inoculum and the growth conditions used were those recommended by the National Committee for Clinical Laboratory Standards for susceptibility testing. A visual estimation of total inhibition of growth and determination of an 80% reduction in the optical density at 492 nm compared with those for the control were taken as endpoints for the calculation of synergy, and a good correlation between both estimates was demonstrated. PMID:8592988

  19. Antifungal activity of silver nanoparticles in combination with nystatin and chlorhexidine digluconate against Candida albicans and Candida glabrata biofilms.

    PubMed

    Monteiro, Douglas R; Silva, Sónia; Negri, Melyssa; Gorup, Luiz F; de Camargo, Emerson R; Oliveira, Rosário; Barbosa, Debora B; Henriques, Mariana

    2013-11-01

    Although silver nanoparticles (SN) have been investigated as an alternative to conventional antifungal drugs in the control of Candida-associated denture stomatitis, the antifungal activity of SN in combination with antifungal drugs against Candida biofilms remains unknown. Therefore, the aim of this study was to evaluate the antifungal efficacy of SN in combination with nystatin (NYT) or chlorhexidine digluconate (CHG) against Candida albicans and Candida glabrata biofilms. The drugs alone or combined with SN were applied on mature Candida biofilms (48 h), and after 24 h of treatment their antibiofilm activities were assessed by total biomass quantification (by crystal violet staining) and colony forming units enumeration. The structure of Candida biofilms was analysed by scanning electron microscopy (SEM) images. The data indicated that SN combined with either NYT or CHG demonstrated synergistic antibiofilm activity, and this activity was dependent on the species and on the drug concentrations used. SEM images showed that some drug combinations were able to disrupt Candida biofilms. The results of this study suggest that the combination of SN with NYT or CHG may have clinical implications in the treatment of denture stomatitis. However, further studies are needed before recommending the use of these drugs safely in clinical situations. PMID:23773119

  20. Impact of brief exposure to antifungal agents on the post-antifungal effect and hemolysin activity of oral Candida albicans

    PubMed Central

    ELLEPOLA, Arjuna Nishantha; KHAJAH, Rana; JAYATILAKE, Sumedha; SAMARANAYAKE, Lakshman; SHARMA, Prem; KHAN, Zia

    2015-01-01

    Post-antifungal effect (PAFE) of Candida and its production of hemolysin are determinants of candidal pathogenicity. Candida albicans is the foremost aetiological agent of oral candidosis, which can be treated with polyene, azole, and echinocandin antifungals. However, once administered, the intraoral concentrations of these drugs tend to be subtherapeutic and transient due to the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, Candida may undergo a brief exposure to antifungal drugs. Objective Therefore, the PAFE and hemolysin production of oral C. albicans isolates following brief exposure to sublethal concentrations of the foregoing antifungals were evaluated. Material and Methods A total of 50 C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sublethal concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for 60 min. Thereafter, the drugs were removed and the PAFE and hemolysin production were determined by previously described turbidometric and plate assays, respectively. Results Nystatin, amphotericin B, caspofungin and ketoconazole induced mean PAFE (hours) of 2.2, 2.18, 2.2 and 0.62, respectively. Fluconazole failed to produce a PAFE. Hemolysin production of these isolates was suppressed with a percentage reduction of 12.27, 13.47, 13.33, 8.53 and 4.93 following exposure to nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole, respectively. Conclusions Brief exposure to sublethal concentrations of antifungal drugs appears to exert an antifungal effect by interfering with the growth as well as hemolysin production of C. albicans. PMID:26398514

  1. Evaluation of Candida albicans formation on feldspathic porcelain subjected to four surface treatment methods.

    PubMed

    Karayazgan, Banu; Atay, Arzu; Saracli, Mehmet Ali; Gunay, Yumushan

    2010-03-01

    Candida albicans, known for its adhesion on prosthetic materials and oral tissues, is the most frequently encountered fungal infection in dentistry. The aim of this study was to evaluate the effects of four different surface treatment methods and immersion in artificial saliva on the surface roughness of and candida adhesion on dental porcelains. The four surface treatment methods were namely: natural glaze, overglaze, dual ion exchange, and polishing. Surface roughness of porcelain was evaluated using a surface profilometer and by SEM. Candida adhesion was examined by culturing two Candida strains on porcelain specimens followed by a colorimetric method using XTT/Coenzyme Q0. It became evident that Candida adhesion was found more in the specimens treated with natural glaze and polishing. Further, by the visual inspection of SEM images and comparison of surface roughness, polished and natural-glazed specimens showed rougher surface characteristics than overglazed and dual-ion-exchanged specimens. PMID:20379024

  2. IL-33 Priming Enhances Peritoneal Macrophage Activity in Response to Candida albicans.

    PubMed

    Tran, Vuvi G; Cho, Hong R; Kwon, Byungsuk

    2014-08-01

    IL-33 is a member of the IL-1 cytokine family and plays a role in the host defense against bacteria, viruses, and fungi. In this study, we investigated the function of IL-33 and its receptor in in vitro macrophage responses to Candida albicans. Our results demonstrate that pre-sensitization of isolated peritoneal macrophages with IL-33 enhanced their pro-inflammatory cytokine production and phagocytic activity in response to C. albicans. These macrophage activities were entirely dependent on the ST2-MyD88 signaling pathway. In addition, pre-sensitization with IL-33 also increased ROS production and the subsequent killing ability of macrophages following C. albicans challenge. These results indicate that IL-33 may increase anti-fungal activity against Candida through macrophage-mediated resistance mechanisms. PMID:25177252

  3. Antifungal Effect of Zataria multiflora Essence on Experimentally Contaminated Acryl Resin Plates With Candida albicans

    PubMed Central

    Jafari, Abbas Ali; Falah Tafti, Abbas; Hoseiny, Seyed Mehdi; Kazemi, Abdolhossein

    2015-01-01

    Background: Adherence and colonization of Candida species particularly C. albicans on denture surfaces, forms a microbial biofilm, which may result denture stomatitis in complete denture users. Objectives: The purpose of the present study was to evaluate the antifungal effect Zataria multiflora essence in removing of Candida albicans biofilms on experimentally contaminated resin acryl plates. Materials and Methods: In the present experimental study, 160 resin acrylic plates (10 × 10 × 1 mm) were contaminated by immersion in 1 × 103 C. albicans suspension for 24 hours to prepare experimental Candida biofilms. The total number of Candida cells, which adhered to 20 randomly selected acryl resin plates was determined as the Candia load before cleaning. The remaining 140 plates were divided to seven groups of 20 and immersed in five concentrations of Zataria multiflora essence from 50 to 3.125 mg/mL as test, 100000 IU nystatin as the positive and sterile physiologic serum as the negative control. The remaining Candida cells on each acryl plate were also enumerated and data were analyzed using the SPSS 16 software with Kruskal-Wallis and Wilcoxon tests. Results: Zataria essence at concentrations of 50 and 25 mg/mL removed 100% of attached Candida cells similar to nystatine (MFC), while weaker Zataria essence solutions cleaned 88%, 60.5% and 44.7% of attached Candida cells. Kruskal-wallis test showed a statistically significant difference between all test groups (P = 0.0001). In this study 12.5 mg/mL concentration of Zataria multiflora was considered as the minimum inhibitory concentration (MIC90). Conclusions: Zataria essence, at concentrations of 50 and 25 mg/mL, effectively removed Candida cells that had adhered to the denture surface, similar to the level of removal observed for 100000 IU nystatin. PMID:25763273

  4. The correlation of virulence, pathogenicity, and itraconazole resistance with SAP activity in Candida albicans strains.

    PubMed

    Feng, Wenli; Yang, Jing; Pan, Yanwei; Xi, Zhiqin; Qiao, Zusha; Ma, Yan

    2016-02-01

    The relationship between SAP2 activity and drug resistance in Candida albicans was investigated by using itraconazole-resistant and itraconazole-sensitive C. albicans isolates. The precipitation zones were measured to analyze SAP2 activity. Mice were classified into itraconazole-resistant and -sensitive C. albicans isolate groups, and a control group, with their survival and mortality rate being observed over 30 days. The relative expression levels of CDR1, CDR2, MDR1, and SAP2 were measured using RT-PCR. It was found that the secreted aspartyl proteinase activity of itraconazole-resistant C. albicans strains was significantly higher than that of itraconazole-sensitive C. albicans strains (P < 0.001). A significantly higher mortality rate was recorded for mice treated with itraconazole-resistant C. albicans than for mice treated with itraconazole-sensitive C. albicans. In regards to the CDR1, CDR2, and MDR1 genes, there was no significant difference between the 2 groups of mice. Positive correlations between SAP2 and MDR1 and between CDR1 and CDR2 were found. The high expression level of SAP2 may relate to the virulence, pathogenicity, and resistance of C. albicans.

  5. Time-course proteomic profile of Candida albicans during adaptation to a fetal serum.

    PubMed

    Aoki, Wataru; Ueda, Tomomi; Tatsukami, Yohei; Kitahara, Nao; Morisaka, Hironobu; Kuroda, Kouichi; Ueda, Mitsuyoshi

    2013-02-01

    Candida albicans is a commensal organism; however, it causes fatal diseases if the host immunity is compromised. The mortality rate is very high due to the lack of effective treatment, leading to ceaseless demand for novel pharmaceuticals. In this study, time-course proteomics of C. albicans during adaptation to fetal bovine serum (FBS) was described. Time-course proteomics is a promising way to understand the exact process of going adaptation in dynamically changing environments. Candida albicans was cultivated in yeast nitrogen base (YNB) ± FBS media, and we identified 1418 proteins in the endpoint samples incubated for 0 or 60 min by a LC-MS/MS system with a long monolithic silica capillary column. Next, we carried out time-course proteomics of the YNB + FBS samples to identify top-priority proteins for adaption to FBS. We identified 16 proteins as nascent/newly synthesized proteins, and they were recognized as candidates of important virulent factors. Gene ontology analysis revealed that transport-related proteins were enriched in the 16 proteins, indicating that C. albicans probably put priority in time on the acquisition of essential elements. Time-course proteomics of C. albicans revealed the order of priority to adapt to FBS. Depicting time-course dynamics will lead to profound understandings of virulence of C. albicans. PMID:23620121

  6. Transcription Factors Efg1 and Bcr1 Regulate Biofilm Formation and Virulence during Candida albicans-Associated Denture Stomatitis.

    PubMed

    Yano, Junko; Yu, Alika; Fidel, Paul L; Noverr, Mairi C

    2016-01-01

    Denture stomatitis (DS) is characterized by inflammation of the oral mucosa in direct contact with dentures and affects a significant number of otherwise healthy denture wearers. The disease is caused by Candida albicans, which readily colonizes and form biofilms on denture materials. While evidence for biofilms on abiotic and biotic surfaces initiating Candida infections is accumulating, a role for biofilms in DS remains unclear. Using an established model of DS in immunocompetent animals, the purpose of this study was to determine the role of biofilm formation in mucosal damage during pathogenesis using C. albicans or mutants defective in morphogenesis (efg1-/-) or biofilm formation (bcr1-/-). For in vivo analyses, rats fitted with custom dentures, consisting of fixed and removable parts, were inoculated with wild-type C. albicans, mutants or reconstituted strains and monitored weekly for fungal burden (denture and palate), body weight and tissue damage (LDH) for up to 8 weeks. C. albicans wild-type and reconstituted mutants formed biofilms on dentures and palatal tissues under in vitro, ex vivo and in vivo conditions as indicated by microscopy demonstrating robust biofilm architecture and extracellular matrix (ECM). In contrast, both efg1-/- and bcr1-/- mutants exhibited poor biofilm growth with little to no ECM. In addition, quantification of fungal burden showed reduced colonization throughout the infection period on dentures and palates of rats inoculated with efg1-/-, but not bcr1-/-, compared to controls. Finally, rats inoculated with efg1-/- and bcr1-/- mutants had minimal palatal tissue damage/weight loss while those inoculated with wild-type or reconstituted mutants showed evidence of tissue damage and exhibited stunted weight gain. These data suggest that biofilm formation is associated with tissue damage during DS and that Efg1 and Bcr1, both central regulators of virulence in C. albicans, have pivotal roles in pathogenesis of DS. PMID:27453977

  7. Transcription Factors Efg1 and Bcr1 Regulate Biofilm Formation and Virulence during Candida albicans-Associated Denture Stomatitis

    PubMed Central

    Yano, Junko; Yu, Alika; Fidel, Paul L.; Noverr, Mairi C.

    2016-01-01

    Denture stomatitis (DS) is characterized by inflammation of the oral mucosa in direct contact with dentures and affects a significant number of otherwise healthy denture wearers. The disease is caused by Candida albicans, which readily colonizes and form biofilms on denture materials. While evidence for biofilms on abiotic and biotic surfaces initiating Candida infections is accumulating, a role for biofilms in DS remains unclear. Using an established model of DS in immunocompetent animals, the purpose of this study was to determine the role of biofilm formation in mucosal damage during pathogenesis using C. albicans or mutants defective in morphogenesis (efg1-/-) or biofilm formation (bcr1-/-). For in vivo analyses, rats fitted with custom dentures, consisting of fixed and removable parts, were inoculated with wild-type C. albicans, mutants or reconstituted strains and monitored weekly for fungal burden (denture and palate), body weight and tissue damage (LDH) for up to 8 weeks. C. albicans wild-type and reconstituted mutants formed biofilms on dentures and palatal tissues under in vitro, ex vivo and in vivo conditions as indicated by microscopy demonstrating robust biofilm architecture and extracellular matrix (ECM). In contrast, both efg1-/- and bcr1-/- mutants exhibited poor biofilm growth with little to no ECM. In addition, quantification of fungal burden showed reduced colonization throughout the infection period on dentures and palates of rats inoculated with efg1-/-, but not bcr1-/-, compared to controls. Finally, rats inoculated with efg1-/- and bcr1-/- mutants had minimal palatal tissue damage/weight loss while those inoculated with wild-type or reconstituted mutants showed evidence of tissue damage and exhibited stunted weight gain. These data suggest that biofilm formation is associated with tissue damage during DS and that Efg1 and Bcr1, both central regulators of virulence in C. albicans, have pivotal roles in pathogenesis of DS. PMID:27453977

  8. Transcription Factors Efg1 and Bcr1 Regulate Biofilm Formation and Virulence during Candida albicans-Associated Denture Stomatitis.

    PubMed

    Yano, Junko; Yu, Alika; Fidel, Paul L; Noverr, Mairi C

    2016-01-01

    Denture stomatitis (DS) is characterized by inflammation of the oral mucosa in direct contact with dentures and affects a significant number of otherwise healthy denture wearers. The disease is caused by Candida albicans, which readily colonizes and form biofilms on denture materials. While evidence for biofilms on abiotic and biotic surfaces initiating Candida infections is accumulating, a role for biofilms in DS remains unclear. Using an established model of DS in immunocompetent animals, the purpose of this study was to determine the role of biofilm formation in mucosal damage during pathogenesis using C. albicans or mutants defective in morphogenesis (efg1-/-) or biofilm formation (bcr1-/-). For in vivo analyses, rats fitted with custom dentures, consisting of fixed and removable parts, were inoculated with wild-type C. albicans, mutants or reconstituted strains and monitored weekly for fungal burden (denture and palate), body weight and tissue damage (LDH) for up to 8 weeks. C. albicans wild-type and reconstituted mutants formed biofilms on dentures and palatal tissues under in vitro, ex vivo and in vivo conditions as indicated by microscopy demonstrating robust biofilm architecture and extracellular matrix (ECM). In contrast, both efg1-/- and bcr1-/- mutants exhibited poor biofilm growth with little to no ECM. In addition, quantification of fungal burden showed reduced colonization throughout the infection period on dentures and palates of rats inoculated with efg1-/-, but not bcr1-/-, compared to controls. Finally, rats inoculated with efg1-/- and bcr1-/- mutants had minimal palatal tissue damage/weight loss while those inoculated with wild-type or reconstituted mutants showed evidence of tissue damage and exhibited stunted weight gain. These data suggest that biofilm formation is associated with tissue damage during DS and that Efg1 and Bcr1, both central regulators of virulence in C. albicans, have pivotal roles in pathogenesis of DS.

  9. Direct identification and recognition of yeast species from clinical material by using albicans ID and CHROMagar Candida plates.

    PubMed Central

    Baumgartner, C; Freydiere, A M; Gille, Y

    1996-01-01

    Two chromogenic media, Albicans ID and CHROMagar Candida agar plates, were compared with a reference medium, Sabouraud-chloramphenicol agar, and standard methods for the identification of yeast species. This study involved 951 clinical specimens. The detection rates for the two chromogenic media for polymicrobial specimens were 20% higher than that for the Sabouraud-chloramphenicol agar plates. The rates of identification of Candida albicans for Albicans ID and CHROMagar Candida agar plates were, respectively, 37.0 and 6.0% after 24 h of incubation and 93.6 and 92.2% after 72 h of incubation, with specificities of 99.8 and 100%. Furthermore, CHROMagar Candida plates identified 13 of 14 Candida tropicalis and 9 of 12 Candida krusei strains after 48 h of incubation. PMID:8789038

  10. The actin-related protein Sac1 is required for morphogenesis and cell wall integrity in Candida albicans.

    PubMed

    Zhang, Bing; Yu, Qilin; Jia, Chang; Wang, Yuzhou; Xiao, Chenpeng; Dong, Yijie; Xu, Ning; Wang, Lei; Li, Mingchun

    2015-08-01

    Candida albicans is a common pathogenic fungus and has aroused widespread attention recently. Actin cytoskeleton, an important player in polarized growth, protein secretion and organization of cell shape, displays irreplaceable role in hyphal development and cell integrity. In this study, we demonstrated a homologue of Saccharomyces cerevisiae Sac1, in C. albicans. It is a potential PIP phosphatase with Sac domain which is related to actin organization, hyphal development, biofilm formation and cell wall integrity. Deletion of SAC1 did not lead to insitiol-auxotroph phenotype in C. albicans, but this gene rescued the growth defect of S. cerevisiae sac1Δ in the insitiol-free medium. Hyphal induction further revealed the deficiency of sac1Δ/Δ in hyphal development and biofilm formation. Fluorescence observation and real time PCR (RT-PCR) analysis suggested both actin and the hyphal cell wall protein Hwp1 were overexpressed and mislocated in this mutant. Furthermore, cell wall integrity (CWI) was largely affected by deletion of SAC1, due to the hypersensitivity to cell wall stress, changed content and distribution of chitin in the mutant. As a result, the virulence of sac1Δ/Δ was seriously attenuated. Taken together, this study provides evidence that Sac1, as a potential PIP phosphatase, is essential for actin organization, hyphal development, CWI and pathogenicity in C. albicans.

  11. Protection of mice from oral Candidiasis by heat-killed enterococcus faecalis, possibly through its direct binding to Candida albicans.

    PubMed

    Ishijima, Sanae A; Hayama, Kazumi; Ninomiya, Kentaro; Iwasa, Masahiro; Yamazaki, Masatoshi; Abe, Shigeru

    2014-01-01

    To develop a new therapy against oral candidiasis, a commensal microorganism, Enterococcus faecalis was tested for its ability to modulate Candida growth in vitro and its therapeutic activities against a murine model in vivo. Addition of heat-killed E. faecalis strain EF2001 (EF2001) isolated from healthy human feces to the culture of C. albicans strain TIMM1768 inhibited adherence of the latter to a microtiter plate in a dose dependent manner and Candida cells surrounded by EF2001 were increased. To examine the protective activities of EF2001 in vivo, heat-killed EF2001 was applied orally before and after inoculation of Candida to the tongue of mice previously immunosuppressed. Two days after inoculation this inoculation, both the symptom score and CFU from swabbed-tongue were significantly reduced in the EF2001-treated animals. Histological analysis indicated that EF2001 may potentiate the accumulation of polymorphnuclear cells near a Candida-infected region. These results suggest that oral administration of EF2001 has protective activity against oral candidiasis and that the in vivo activity may be reflected by direct interaction between EF2001 and Candida cells in vitro and the potentiation of an immunostimulatory effect of EF2001.

  12. DNA content, kinetic complexity, and the ploidy question in Candida albicans.

    PubMed Central

    Riggsby, W S; Torres-Bauza, L J; Wills, J W; Townes, T M

    1982-01-01

    Candida albicans is a dimorphic fungus that is pathogenic for humans. No sexual cycle has been reported for this fungus, and earlier reports have differed on whether typical strains of C. albicans are haploid or diploid. Previous estimates of the DNA content of C. albicans varied by one order of magnitude. We used three independent methods to measure the kinetic complexity of the single-copy DNA from a typical strain of C. albicans (strain H317) to determine the DNA content per haploid genote; we obtained values of 15 and 20 fg per cell by using S1 nuclease and hydroxyapatite assays, respectively. Optical assays for DNA reassociation kinetics, although not definitive in themselves, yielded values in this range. Chemical measurements of the DNA content of several typical strains, including strain H317, yielded values clustered about a mean of 37 fg per cell. We concluded that these strains are diploid. PMID:6765567

  13. Increase of mouse resistance to Candida albicans infection by thymosin alpha 1.

    PubMed Central

    Bistoni, F; Marconi, P; Frati, L; Bonmassar, E; Garaci, E

    1982-01-01

    Studies were carried out to assess the ability of thymosin alpha 1 to prolong the survival of mice challenged with Candida albicans. Two- to four-month-old mice were treated with graded doses of thymosin alpha 1 before, after, or before and after intravenous challenge with C. albicans. Significant resistance ot lethal infection was afforded by 100 micrograms of thymosin alpha 1 per kg given before or before and after challenge, whereas no protection was found in mice treated with thymosin alpha 1 administered at any dose level after inoculation. Pretreatment with thymosin alpha 1 also prevented the increased susceptibility to C. albicans infection of mice pretreated with cyclophosphamide on day -6. The results showed that thymosin alpha 1 was capable of protecting untreated or cyclophosphamide-pretreated mice from C. albicans infection at an optimal dose and schedule of administration. PMID:7085074

  14. Additive potential of ginger starch on antifungal potency of honey against Candida albicans

    PubMed Central

    Moussa, Ahmed; Noureddine, Djebli; SM, Hammoudi; Saad, Aissat; Bourabeh, Akila; Houari, Hemida

    2012-01-01

    Objective To evaluate the additive action of ginger starch on the antifungal activity of honey against Candida albicans (C. albicans). Methods C. albicans was used to determine the minimum inhibitory concentration (MIC) of four varieties of Algerian honey. Lower concentrations of honey than the MIC were incubated with a set of concentrations of starch and then added to media to determine the minimum additive inhibitory concentration (MAIC). Results The MIC for the four varieties of honey without starch against C. albicans ranged between 38% and 42% (v/v). When starch was incubated with honey and then added to media, a MIC drop was noticed with each variety. MAIC of the four varieties ranged between 32% honey (v/v) with 4% starch and 36% honey (v/v) with 2% starch. Conclusions The use of ginger starch allows honey benefit and will constitute an alternative way against the resistance to antifungal agents. PMID:23569909

  15. Ascorbic acid inhibition of Candida albicans Hsp90-mediated morphogenesis occurs via the transcriptional regulator Upc2.

    PubMed

    Van Hauwenhuyse, Frédérique; Fiori, Alessandro; Van Dijck, Patrick

    2014-10-01

    Morphogenetic transitions of the opportunistic fungal pathogen Candida albicans are influenced by temperature changes, with induction of filamentation upon a shift from 30 to 37°C. Hsp90 was identified as a major repressor of an elongated cell morphology at low temperatures, as treatment with specific inhibitors of Hsp90 results in elongated growth forms at 30°C. Elongated growth resulting from a compromised Hsp90 is considered neither hyphal nor pseudohyphal growth. It has been reported that ascorbic acid (vitamin C) interferes with the yeast-to-hypha transition in C. albicans. In the present study, we show that ascorbic acid also antagonizes the morphogenetic change caused by hampered Hsp90 function. Further analysis revealed that Upc2, a transcriptional regulator of genes involved in ergosterol biosynthesis, and Erg11, the target of azole antifungals, whose expression is in turn regulated by Upc2, are required for this antagonism. Ergosterol levels correlate with elongated growth and are reduced in cells treated with the Hsp90 inhibitor geldanamycin (GdA) and restored by cotreatment with ascorbic acid. In addition, we show that Upc2 appears to be required for ascorbic acid-mediated inhibition of the antifungal activity of fluconazole. These results identify Upc2 as a major regulator of ascorbic acid-induced effects in C. albicans and suggest an association between ergosterol content and elongated growth upon Hsp90 compromise. PMID:25084864

  16. Pph3 dephosphorylation of Rad53 is required for cell recovery from MMS-induced DNA damage in Candida albicans.

    PubMed

    Wang, Haitao; Gao, Jiaxin; Li, Wanjie; Wong, Ada Hang-Heng; Hu, Kangdi; Chen, Kun; Wang, Yue; Sang, Jianli

    2012-01-01

    The pathogenic fungus Candida albicans switches from yeast growth to filamentous growth in response to genotoxic stresses, in which phosphoregulation of the checkpoint kinase Rad53 plays a crucial role. Here we report that the Pph3/Psy2 phosphatase complex, known to be involved in Rad53 dephosphorylation, is required for cellular responses to the DNA-damaging agent methyl methanesulfonate (MMS) but not the DNA replication inhibitor hydroxyurea (HU) in C. albicans. Deletion of either PPH3 or PSY2 resulted in enhanced filamentous growth during MMS treatment and continuous filamentous growth even after MMS removal. Moreover, during this growth, Rad53 remained hyperphosphorylated, MBF-regulated genes were downregulated, and hypha-specific genes were upregulated. We have also identified S461 and S545 on Rad53 as potential dephosphorylation sites of Pph3/Psy2 that are specifically involved in cellular responses to MMS. Therefore, our studies have identified a novel molecular mechanism mediating DNA damage response to MMS in C. albicans.

  17. Effect of Candida albicans on Intestinal Ischemia-reperfusion Injury in Rats

    PubMed Central

    Yan, Lei; Wu, Chun-Rong; Wang, Chen; Yang, Chun-Hui; Tong, Guang-Zhi; Tang, Jian-Guo

    2016-01-01

    Background: Inflammation is supposed to play a key role in the pathophysiological processes of intestinal ischemia-reperfusion injury (IIRI), and Candida albicans in human gut commonly elevates inflammatory cytokines in intestinal mucosa. This study aimed to explore the effect of C. albicans on IIRI. Methods: Fifty female Wistar rats were divided into five groups according to the status of C. albicans infection and IIRI operation: group blank and sham; group blank and IIRI; group cefoperazone plus IIRI; group C. albicans plus cefoperazone and IIRI (CCI); and group C. albicans plus cefoperazone and sham. The levels of inflammatory factors tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and diamine oxidase (DAO) measured by enzyme-linked immunosorbent assay were used to evaluate the inflammation reactivity as well as the integrity of small intestine. Histological scores were used to assess the mucosal damage, and the C. albicans blood translocation was detected to judge the permeability of intestinal mucosal barrier. Results: The levels of inflammatory factors TNF-α, IL-6, and IL-1β in serum and intestine were higher in rats undergone both C. albicans infection and IIRI operation compared with rats in other groups. The levels of DAO (serum: 44.13 ± 4.30 pg/ml, intestine: 346.21 ± 37.03 pg/g) and Chiu scores (3.41 ± 1.09) which reflected intestinal mucosal disruption were highest in group CCI after the operation. The number of C. albicans translocated into blood was most in group CCI ([33.80 ± 6.60] ×102 colony forming unit (CFU)/ml). Conclusion: Intestinal C. albicans infection worsened the IIRI-induced disruption of intestinal mucosal barrier and facilitated the subsequent C. albicans translocation and dissemination. PMID:27411459

  18. Candida albicans exposures, sex specificity and cognitive deficits in schizophrenia and bipolar disorder

    PubMed Central

    Severance, Emily G; Gressitt, Kristin L; Stallings, Catherine R; Katsafanas, Emily; Schweinfurth, Lucy A; Savage, Christina L; Adamos, Maria B; Sweeney, Kevin M; Origoni, Andrea E; Khushalani, Sunil; Leweke, F Markus; Dickerson, Faith B; Yolken, Robert H

    2016-01-01

    Immune aberrations in schizophrenia and bipolar disorder have led to the hypotheses that infectious agents or corresponding immune responses might contribute to psychiatric etiopathogeneses. We investigated case–control differences in exposure to the opportunistic fungal pathogen, Candida albicans, and examined associations with cognition, medication, lifestyle, and somatic conditions. We quantified C. albicans IgG antibodies in two cohorts totaling 947 individuals and evaluated odds ratios (OR) of exposure with psychiatric disorder using multivariate regressions. The case–control cohort included 261 with schizophrenia, 270 with bipolar disorder, and 277 non-psychiatric controls; the second included 139 with first-episode schizophrenia, 78 of whom were antipsychotic naive. No differences in C. albicans exposures were found until diagnostic groups were stratified by sex. In males, C. albicans seropositivity conferred increased odds for a schizophrenia diagnosis (OR 2.04–9.53, P⩽0.0001). In females, C. albicans seropositivity conferred increased odds for lower cognitive scores on Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in schizophrenia (OR 1.12, P⩽0.004), with significant decreases on memory modules for both disorders (P⩽0.0007–0.03). C. albicans IgG levels were not impacted by antipsychotic medications. Gastrointestinal (GI) disturbances were associated with elevated C. albicans in males with schizophrenia and females with bipolar disorder (P⩽0.009–0.02). C. albicans exposure was associated with homelessness in bipolar males (P⩽0.0015). In conclusion, sex-specific C. albicans immune responses were evident in psychiatric disorder subsets. Inquiry regarding C. albicans infection or symptoms may expedite amelioration of this treatable comorbid condition. Yeast exposure as a risk factor for schizophrenia and its associated cognitive and GI effects require further investigation including the possible contribution of

  19. Candida albicans exposures, sex specificity and cognitive deficits in schizophrenia and bipolar disorder.

    PubMed

    Severance, Emily G; Gressitt, Kristin L; Stallings, Catherine R; Katsafanas, Emily; Schweinfurth, Lucy A; Savage, Christina L; Adamos, Maria B; Sweeney, Kevin M; Origoni, Andrea E; Khushalani, Sunil; Leweke, F Markus; Dickerson, Faith B; Yolken, Robert H

    2016-01-01

    Immune aberrations in schizophrenia and bipolar disorder have led to the hypotheses that infectious agents or corresponding immune responses might contribute to psychiatric etiopathogeneses. We investigated case-control differences in exposure to the opportunistic fungal pathogen, Candida albicans, and examined associations with cognition, medication, lifestyle, and somatic conditions. We quantified C. albicans IgG antibodies in two cohorts totaling 947 individuals and evaluated odds ratios (OR) of exposure with psychiatric disorder using multivariate regressions. The case-control cohort included 261 with schizophrenia, 270 with bipolar disorder, and 277 non-psychiatric controls; the second included 139 with first-episode schizophrenia, 78 of whom were antipsychotic naive. No differences in C. albicans exposures were found until diagnostic groups were stratified by sex. In males, C. albicans seropositivity conferred increased odds for a schizophrenia diagnosis (OR 2.04-9.53, P⩽0.0001). In females, C. albicans seropositivity conferred increased odds for lower cognitive scores on Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in schizophrenia (OR 1.12, P⩽0.004), with significant decreases on memory modules for both disorders (P⩽0.0007-0.03). C. albicans IgG levels were not impacted by antipsychotic medications. Gastrointestinal (GI) disturbances were associated with elevated C. albicans in males with schizophrenia and females with bipolar disorder (P⩽0.009-0.02). C. albicans exposure was associated with homelessness in bipolar males (P⩽0.0015). In conclusion, sex-specific C. albicans immune responses were evident in psychiatric disorder subsets. Inquiry regarding C. albicans infection or symptoms may expedite amelioration of this treatable comorbid condition. Yeast exposure as a risk factor for schizophrenia and its associated cognitive and GI effects require further investigation including the possible contribution of gut

  20. Treatment with probiotics in experimental oral colonization by Candida albicans in murine model (DBA/2).

    PubMed

    Matsubara, V H; Silva, E G; Paula, C R; Ishikawa, K H; Nakamae, A E M

    2012-04-01

    The aim of this study is to evaluate the oral colonization by Candida albicans in experimental murine immunosuppressed DBA/2 and treatment with probiotic bacteria. To achieve these objectives, 152 DBA/2-immunosuppressed mice were orally inoculated with a suspension of C. albicans containing 10(8) viable yeast cells, the animals were treated with nystatin or with the probiotics (Lactobacillus acidophilus and Lactobacillus rhamnosus). Evaluations were performed by Candida count from oral mucosa swabbing. The oral mucosa colonization by C. albicans started at day 1 after inoculation, remained maximal from day 3 until day 7, and then decreased significantly. Probiotics reduced the C. albicans colonization significantly on the oral mucosa in comparison with the untreated animal group. In the group treated with L. rhamnosus, the reduction in yeast colonization was significantly higher compared with that of the group receiving nystatin. Immunosuppressed animal model DBA/2 is a relevant model for experimental Candida oral colonization, and the treatment with probiotics in this model may be an effective alternative to prevent it.

  1. Candida albicans-induced agglutinin and immunoglobulin E responses in mice.

    PubMed Central

    Winterrowd, G E; Cutler, J E

    1983-01-01

    Mice varied in their ability to make detectable antibody responses to cell surface determinants of Candida albicans depending upon the antigen preparation and the immunization schedule used. Immunoglobulin M (IgM) appeared to be the major class of antibody responsible for the C. albicans-agglutinating activity of the immune sera. Various inbred strains of mice injected with a ribosomal fraction from C. albicans produced a low titer (average, 4 to 8) of yeast cell agglutinins and a higher titer (64 to 512) of IgE antibodies detected by passive cutaneous anaphylaxis (PCA) in rats. The two kinds of antibodies appeared to be specific for different antigens because the agglutinin, but not IgE, could be removed by absorbing the serum with a polysaccharide from the cell wall of C. albicans, but the polysaccharide did not provoke the PCA reaction. C. albicans-specific IgE antibodies showed cross-reactivity (PCA) with ribosomal antigens from a strain of C. albicans and C. tropicalis, but PCA reactions could not be elicited with similar antigen preparations from other yeast species. IgE responses were also detected in over 20% of the mice infected intravenously or intraperitoneally with live C. albicans. PMID:6190755

  2. Candida albicans Amphotericin B-Tolerant Persister Formation is Closely Related to Surface Adhesion.

    PubMed

    Sun, Jing; Li, Zhigang; Chu, Haoyue; Guo, Jing; Jiang, Guangshui; Qi, Qingguo

    2016-02-01

    Candida albicans persisters have so far been observed only in biofilm environment; the biofilm element(s) that trigger(s) persister formation are still unknown. In this study, we tried to further elucidate the possible relationship between C. albicans persisters and the early phases of biofilm formation, especially the surface adhesion phase. Three C. albicans strains were surveyed for the formation of persisters. We tested C. albicans persister formation dynamically at different time points during the process of adhesion and biofilm formation. The number of persister cells was determined based on an assessment of cell viability after amphotericin B treatment and colony-forming unit assay. None of the planktonic cultures contained persisters. Immediately following adhesion of C. albicans cells to the surface, persister cells emerged and the proportion of persisters reached a peak of 0.2-0.69 % in approximately 2-h biofilm. As the biofilm matured, the proportion of persisters decreased and was only 0.01-0.02 % by 24 h, while the number of persisters remained stable with no significant change. Persisters were not detected in the absence of an attachment surface which was pre-coated. Persisters were also absent in biofilms that were scraped to disrupt surface adhesion prior to amphotericin B treatment. These results indicate that C. albicans antifungal-tolerant persisters are produced mainly in surface adhesion phase and surface adhesion is required for the emergence and maintenance of C. albicans persisters.

  3. Essential Functional Modules for Pathogenic and Defensive Mechanisms in Candida albicans Infections

    PubMed Central

    Tsai, I-Chun; Lin, Che; Chuang, Yung-Jen

    2014-01-01

    The clinical and biological significance of the study of fungal pathogen Candida albicans (C. albicans) has markedly increased. However, the explicit pathogenic and invasive mechanisms of such host-pathogen interactions have not yet been fully elucidated. Therefore, the essential functional modules involved in C. albicans-zebrafish interactions were investigated in this study. Adopting a systems biology approach, the early-stage and late-stage protein-protein interaction (PPI) networks for both C. albicans and zebrafish were constructed. By comparing PPI networks at the early and late stages of the infection process, several critical functional modules were identified in both pathogenic and defensive mechanisms. Functional modules in C. albicans, like those involved in hyphal morphogenesis, ion and small molecule transport, protein secretion, and shifts in carbon utilization, were seen to play important roles in pathogen invasion and damage caused to host cells. Moreover, the functional modules in zebrafish, such as those involved in immune response, apoptosis mechanisms, ion transport, protein secretion, and hemostasis-related processes, were found to be significant as defensive mechanisms during C. albicans infection. The essential functional modules thus determined could provide insights into the molecular mechanisms of host-pathogen interactions during the infection process and thereby devise potential therapeutic strategies to treat C. albicans infection. PMID:24757665

  4. Adherence of Candida albicans to a cell surface polysaccharide receptor on Streptococcus gordonii.

    PubMed Central

    Holmes, A R; Gopal, P K; Jenkinson, H F

    1995-01-01

    Candida albicans ATCC 10261 and CA2 bound to cells of the oral bacteria Streptococcus gordonii, Streptococcus oralis, and Streptococcus sanguis when these bacteria were immobilized onto microtiter plate wells, but they did not bind to cells of Streptococcus mutans or Streptococcus salivarius. Cell wall polysaccharide was extracted with alkali from S. gordonii NCTC 7869, the streptococcal species to which C. albicans bound with highest affinity, and was effective in blocking the coaggregation of C. albicans and S. gordonii cells in the fluid phase. When fixed to microtiter plate wells, the S. gordonii polysaccharide was bound by all strains of C. albicans tested. The polysaccharide contained Rha, Glc, GalNAc, GlcNAc, and Gal and was related compositionally to previously characterized cell wall polysaccharides from strains of S. oralis and S. sanguis. The adherence of yeast cells to the immobilized polysaccharide was not inhibitable by a number of saccharides. Antiserum raised to the S. gordonii NCTC 7869 polysaccharide blocked adherence of C. albicans ATCC 10261 to the polysaccharide. The results identify a complex cell wall polysaccharide of S. gordonii as the coaggregation receptor for C. albicans. Adherent interactions of yeast cells with streptococci and other bacteria may be important for colonization of both hard and soft oral surfaces by C. albicans. PMID:7729891

  5. Modulation of Candida albicans virulence by bacterial biofilms on titanium surfaces.

    PubMed

    Cavalcanti, Yuri Wanderley; Wilson, Melanie; Lewis, Michael; Del-Bel-Cury, Altair Antoninha; da Silva, Wander José; Williams, David W

    2016-01-01

    Whilst Candida albicans occurs in peri-implant biofilms, its role in peri-implantitis remains unclear. This study therefore examined the virulence of C. albicans in mixed-species biofilms on titanium surfaces. Biofilms of C. albicans (Ca), C. albicans with streptococci (Streptococcus sanguinis, S. mutans) (Ca-Ss-Sm) and those incorporating Porphyromonas gingivalis (Ca-Pg and Ca-Ss-Sm-Pg) were developed. Expression of C. albicans genes associated with adhesion (ALS1, ALS3, HWP1) and hydrolytic enzymes (SAP2, SAP4, SAP6, PLD1) was measured and hyphal production by C. albicans quantified. Compared with Ca biofilms, significant (p<0.05) up-regulation of ALS3, HWP1, SAP2 and SAP6, and hyphal production occurred in biofilms containing streptococci (Ca-Ss-Sm). In Ca-Pg biofilms, down-regulation of HWP1 and SAP4 expression, with reduced hyphal production occurred. Ca-Ss-Sm-Pg biofilms had increased hyphal proportions and up-regulation of ALS3, SAP2 and SAP6. In conclusion, C. albicans expressed virulence factors in biofilms that could contribute to peri-implantitis, but this was dependent on associated bacterial species.

  6. C3bi-binding protein on Candida albicans: temperature-dependent expression and relationship to human complement receptor type 3.

    PubMed Central

    Eigentler, A; Schulz, T F; Larcher, C; Breitwieser, E M; Myones, B L; Petzer, A L; Dierich, M P

    1989-01-01

    We investigated in detail the previously described capacity of pseudohyphae of Candida albicans to bind C3-coated particles. We show that the expression of the C3bi receptor of C. albicans was dependent upon the growth temperature of the fungi. C. albicans grown at 30 degrees C bound strongly to EAC1423bi, whereas those cells grown at 38.5 degrees C were completely devoid of this capacity. The molecule responsible for the attachment of EAC1423bi was heat labile and trypsin sensitive. Several, but not all, monoclonal antibodies to the alpha-chain of human complement receptor type 3 (CR3) stained C. albicans, and this reactivity was expressed in parallel with the capacity of C. albicans to bind EAC1423bi, i.e., both were dependent on the growth temperature of the fungi and were trypsin sensitive. In contrast to CR3, the binding of EAC1423bi to C. albicans did not require the presence of divalent cations. Rabbit immunoglobulin G antibodies directed against C. albicans inhibited the binding of EAC1423bi to C. albicans but not to human CR3. These inhibiting IgG antibodies recognized antigens expressed on the surface of pseudohyphae but not those of yeast cells. OKM-1, a monoclonal antibody to human CR3 inhibited the attachment of EAC1423bi to CR3 and also to C. albicans. OKM-1 precipitated a 130-kilodalton band from solubilized 125I-labeled C. albicans. We conclude that the complement receptors on C. albicans and human CR3 were antigenically related but not identical and that they differed in their functional characteristics. Images PMID:2521478

  7. Isolation, characterization and mechanism of action of an antimicrobial peptide from Lecythis pisonis seeds with inhibitory activity against Candida albicans.

    PubMed

    Vieira, Maria Eliza Brambila; Vasconcelos, Ilka Maria; Machado, Olga Lima Tavares; Gomes, Valdirene Moreira; Carvalho, André de Oliveira

    2015-09-01

    Antimicrobial peptides (AMPs) are produced by a range of organisms as a first line of defense against invaders or competitors. Owing to their broad antimicrobial activity, AMPs have attracted attention as a potential source of chemotherapeutic drugs. The increasing prevalence of infections caused by Candida species as opportunistic pathogens in immunocompromised patients requires new drugs. Lecythis pisonis is a Lecythydaceae tree that grows in Brazil. The AMPs produced by this tree have not been described previously. We describe the isolation of 12 fractions enriched in peptides from L. pisonis seeds. Of the 12 fractions, at 10 μg/ml, the F4 fraction had the strongest growth inhibitory effect (53.7%) in Candida albicans, in addition to a loss of viability of 94.9%. The F4 fraction was separated into seven sub-fractions by reversed-phase chromatography. The F4.7' fraction had the strongest activity at 10 μg/ml, inhibiting C. albicans growth by 38.5% and a 69.3% loss of viability. The peptide in F4.7' was sequenced and was found to be similar to plant defensins. For this reason, the peptide was named L. pisonis defensin 1 (Lp-Def1). The mechanism of action that is responsible for C. albicans inhibition by Lp-Def1 includes a slight increase of reactive oxygen species induction and a significant loss of mitochondrial function. The results described here support the future development of plant defensins, specifically Lp-Def1, as new therapeutic substances against fungi, especially C. albicans. PMID:26245301

  8. Prevalence and antifungal susceptibility of Candida albicans and its related species Candida dubliniensis and Candida africana isolated from vulvovaginal samples in a hospital of Argentina.

    PubMed

    Theill, Laura; Dudiuk, Catiana; Morano, Susana; Gamarra, Soledad; Nardin, María Elena; Méndez, Emilce; Garcia-Effron, Guillermo

    2016-01-01

    Candida africana taxonomical status is controversial. It was proposed as a separate species within the Candida albicans species complex; however, phylogenetic analyses suggested that it is an unusual variety of C. albicans. The prevalence of C. albicans-related species (Candida dubliniensis and C. africana) as vulvovaginal pathogens is not known in Argentina. Moreover, data on antifungal susceptibility of isolates causing vulvovaginal candidiasis is scarce. The aims of this study were to establish the prevalence of C. dubliniensis and C. africana in vaginal samples and to evaluate the antifungal susceptibilities of vaginal C. albicans species complex strains. We used a molecular-based method coupled with a new pooled DNA extraction methodology to differentiate C. dubliniensis and C. africana in a collection of 287 strains originally identified as C. albicans isolated from an Argentinian hospital during 2013. Antifungal susceptibilities to fluconazole, clotrimazole, itraconazole, voriconazole, nystatin, amphotericin B and terbinafine were evaluated by using the CLSI M27-A3 and M27-S4 documents. Of the 287 isolates, 4 C. dubliniensis and one C. africana strains (1.39% and 0.35% prevalence, respectively) were identified. This is the first description of C. africana in Argentina and its identification was confirmed by sequencing the ITS2 region and the hwp1 gene. C. dubliniensis and C. africana strains showed very low MIC values for all the tested antifungals. Fluconazole-reduced-susceptibility and azole cross-resistance were observed in 3.55% and 1.41% of the C. albicans isolates, respectively. These results demonstrate that antifungal resistance is still a rare phenomenon in this kind of isolates.

  9. Prevalence and antifungal susceptibility of Candida albicans and its related species Candida dubliniensis and Candida africana isolated from vulvovaginal samples in a hospital of Argentina.

    PubMed

    Theill, Laura; Dudiuk, Catiana; Morano, Susana; Gamarra, Soledad; Nardin, María Elena; Méndez, Emilce; Garcia-Effron, Guillermo

    2016-01-01

    Candida africana taxonomical status is controversial. It was proposed as a separate species within the Candida albicans species complex; however, phylogenetic analyses suggested that it is an unusual variety of C. albicans. The prevalence of C. albicans-related species (Candida dubliniensis and C. africana) as vulvovaginal pathogens is not known in Argentina. Moreover, data on antifungal susceptibility of isolates causing vulvovaginal candidiasis is scarce. The aims of this study were to establish the prevalence of C. dubliniensis and C. africana in vaginal samples and to evaluate the antifungal susceptibilities of vaginal C. albicans species complex strains. We used a molecular-based method coupled with a new pooled DNA extraction methodology to differentiate C. dubliniensis and C. africana in a collection of 287 strains originally identified as C. albicans isolated from an Argentinian hospital during 2013. Antifungal susceptibilities to fluconazole, clotrimazole, itraconazole, voriconazole, nystatin, amphotericin B and terbinafine were evaluated by using the CLSI M27-A3 and M27-S4 documents. Of the 287 isolates, 4 C. dubliniensis and one C. africana strains (1.39% and 0.35% prevalence, respectively) were identified. This is the first description of C. africana in Argentina and its identification was confirmed by sequencing the ITS2 region and the hwp1 gene. C. dubliniensis and C. africana strains showed very low MIC values for all the tested antifungals. Fluconazole-reduced-susceptibility and azole cross-resistance were observed in 3.55% and 1.41% of the C. albicans isolates, respectively. These results demonstrate that antifungal resistance is still a rare phenomenon in this kind of isolates. PMID:26922471

  10. Tpd3-Pph21 phosphatase plays a direct role in Sep7 dephosphorylation in Candida albicans.

    PubMed

    Liu, Qizheng; Han, Qi; Wang, Na; Yao, Guangyin; Zeng, Guisheng; Wang, Yanming; Huang, Zhenxing; Sang, Jianli; Wang, Yue

    2016-07-01

    Septins are a component of the cytoskeleton and play important roles in diverse cellular processes including cell cycle control, cytokinesis and polarized growth. In fungi, septin organization, dynamics and function are regulated by phosphorylation, and several kinases responsible for the phosphorylation of several septins have been identified. However, little is known about the phosphatases that dephosphorylate septins. Here, we report the characterization of Tpd3, a structural subunit of the PP2A family of phosphatases, in the pathogenic fungus Candida albicans. We found that tpd3Δ/Δ cells are defective in hyphal growth and grow as pseudohyphae under yeast growth conditions with aberrant septin organization. Western blotting detected hyperphosphorylation of the septin Sep7 in cells lacking Tpd3. Tpd3 and Sep7 colocalize at the bud neck and can coimmunoprecipitate. Furthermore, we discovered similar defects in cells lacking Pph21, a catalytic subunit of the PP2A family, and its physical association with Tpd3. Importantly, purified Tpd3-Pph21 complexes can dephosphorylate Sep7 in vitro. Together, our findings strongly support the idea that the Tpd3-Pph21 complex dephosphorylates Sep7 and regulates morphogenesis and cytokinesis. The tpd3Δ/Δ mutant is greatly reduced in virulence in mice, providing a potential antifungal target.

  11. Transcriptional response of Candida albicans biofilms following exposure to 2-amino-nonyl-6-methoxyl-tetralin muriate

    PubMed Central

    Liang, Rong-mei; Cao, Yong-bing; Zhou, You-jun; Xu, Yi; Gao, Ping-hui; Dai, Bao-di; Yang, Feng; Tang, Hui; Jiang, Yuan-ying

    2010-01-01

    Aim: To identify changes in the gene expression profile of Candida albicans (C albicans) biofilms following exposed to 2-amino-nonyl-6-methoxyl-tetralin muriate(10b) and clarify the mechanism of 10b against C albicans biofilms. Methods: Anti-biofilm activity of 10b was assessed by tetrazolium (XTT) reduction assay and the action mechanism against biofilms was investigated by cDNA microarray analysis and real-time RT-PCR assay. Results: Ten differentially expressed genes were directly linked to biofilm formation and filamentous or hyphal growth (eg, NRG1, ECE1 and CSA1). Decreased gene expression was involved in glycolysis (eg, HXK2 and PFK1) and antioxidant defense (eg, SOD5), while increased gene expression was associated with enzymes that specifically hydrolyzed β-1,3 glucan (XOG1), and with lipid, fatty acid and sterol metabolism (eg, SLD1, ERG6 and ERG2). Functional analysis indicated that addition of anti-oxidant ascorbic acid reduced inhibitory efficiency of 10b on mature biofilm. Conclusion: Inhibition of 10b on biofilm formation possibly depends on impairing the ability of C albicans to change its morphology via altering the expression of biofilm formation genes. Mitochondrial aerobic respiration shift and endogenous ROS augmentation might be a major contribution to reduce mature biofilm metabolic activity. The data may be useful for the development of new strategies to reduce the incidence of device-associated infections. PMID:20383169

  12. Mannan structural complexity is decreased when Candida albicans is cultivated in blood or serum at physiological temperature

    PubMed Central

    Lowman, Douglas W.; Ensley, Harry E.; Greene, Rachel R.; Knagge, Kevin J.; Williams, David L.; Kruppa, Michael D.

    2011-01-01

    The Candida albicans cell wall provides an architecture that allows for the organism to survive environmental stresses as well as interaction with host tissues. Previous work has focused on growing C. albicans on media such as Sabouraud or YPD at 30 °C. Because C. albicans normally colonizes a host, we hypothesized that cultivation on blood or serum at 37 °C would result in structural changes in cell wall mannan. C. albicans SC5314 was inoculated onto YPD, 5% blood, or 5% serum agar media three successive times at 30 °C and 37 °C, then cultivated overnight at 30 °C in YPD. The mannan was extracted and characterized using 1D and 2D 1H NMR techniques. At 30 °C cells grown in blood and serum contain less acid-stable terminal β-(1→2)-linked D-mannose and α-(1→2)-linked D-mannose-containing side chains, while the acid-labile side chains of mannan grown in blood and serum contain fewer β-Man-(1→2)-α-Man-(1→ side chains. The decrement in acid-stable mannan side chains is greater at 37 °C than at 30 °C. Cells grown on blood at 37 °C show fewer →6)-α-Man-(1→ structural motifs in the acid-stable polymer backbone. The data indicate that C. albicans, grown on media containing host derived components, produces less complex mannan. This is accentuated when the cells are cultured at 37 °C. This study demonstrates that the C. albicans cell wall is a dynamic and adaptive organelle, which alters its structural phenotype in response to growth in host-derived media at physiological temperature. PMID:22030461

  13. Roles of IL-33 in Resistance and Tolerance to Systemic Candida albicans Infections

    PubMed Central

    Park, Sang Jun; Cho, Hong Rae

    2016-01-01

    IL-33 is a multifunctional cytokine that is released in response to a variety of intrinsic and extrinsic stimuli. The role of IL-33 in Candida albicans infections is just beginning to be revealed. This cytokine has beneficial effects on host defense against systemic C. albicans infections, and it promotes resistance mechanisms by which the immune system eliminates the invading fungal pathogens; and it also elevates host tolerance by reducing the inflammatory response and thereby, potentially, tissue damage. Thus, IL-33 is classified as a cytokine that has evolved functionally to protect the host from damage by pathogens and immunopathology. PMID:27340384

  14. Comparative Analysis of Protein Glycosylation Pathways in Humans and the Fungal Pathogen Candida albicans

    PubMed Central

    Martínez-Duncker, Iván; Díaz-Jímenez, Diana F.; Mora-Montes, Héctor M.

    2014-01-01

    Protein glycosylation pathways are present in all kingdoms of life and are metabolic pathways found in all the life kingdoms. Despite sharing commonalities in their synthesis, glycans attached to glycoproteins have species-specific structures generated by the presence of different sets of enzymes and acceptor substrates in each organism. In this review, we present a comparative analysis of the main glycosylation pathways shared by humans and the fungal pathogen Candida albicans: N-linked glycosylation, O-linked mannosylation and glycosylphosphatidylinositol-anchorage. The knowledge of similarities and divergences between these metabolic pathways could help find new pharmacological targets for C. albicans infection. PMID:25104959

  15. Dissecting Candida albicans Infection from the Perspective of C. albicans Virulence and Omics Approaches on Host–Pathogen Interaction: A Review

    PubMed Central

    Chin, Voon Kin; Lee, Tze Yan; Rusliza, Basir; Chong, Pei Pei

    2016-01-01

    Candida bloodstream infections remain the most frequent life-threatening fungal disease, with Candida albicans accounting for 70% to 80% of the Candida isolates recovered from infected patients. In nature, Candida species are part of the normal commensal flora in mammalian hosts. However, they can transform into pathogens once the host immune system is weakened or breached. More recently, mortality attributed to Candida infections has continued to increase due to both inherent and acquired drug resistance in Candida, the inefficacy of the available antifungal drugs, tedious diagnostic procedures, and a rising number of immunocompromised patients. Adoption of animal models, viz. minihosts, mice, and zebrafish, has brought us closer to unraveling the pathogenesis and complexity of Candida infection in human hosts, leading towards the discovery of biomarkers and identification of potential therapeutic agents. In addition, the advancement of omics technologies offers a holistic view of the Candida-host interaction in a non-targeted and non-biased manner. Hence, in this review, we seek to summarize past and present milestone findings on C. albicans virulence, adoption of animal models in the study of C. albicans infection, and the application of omics technologies in the study of Candida–host interaction. A profound understanding of the interaction between host defense and pathogenesis is imperative for better design of novel immunotherapeutic strategies in future. PMID:27763544

  16. Activity of antimicrobial peptide mimetics in the oral cavity: I. Activity against biofilms of Candida albicans.

    PubMed

    Hua, J; Yamarthy, R; Felsenstein, S; Scott, R W; Markowitz, K; Diamond, G

    2010-12-01

    Naturally occurring antimicrobial peptides hold promise as therapeutic agents against oral pathogens such as Candida albicans but numerous difficulties have slowed their development. Synthetic, non-peptidic analogs that mimic the properties of these peptides have many advantages and exhibit potent, selective antimicrobial activity. Several series of mimetics (with molecular weight < 1000) were developed and screened against oral Candida strains as a proof-of-principle for their antifungal properties. One phenylalkyne and several arylamide compounds with reduced mammalian cytotoxicities were found to be active against C. albicans. These compounds demonstrated rapid fungicidal activity in liquid culture even in the presence of saliva, and demonstrated synergy with standard antifungal agents. When assayed against biofilms grown on denture acrylic, the compounds exhibited potent fungicidal activity as measured by metabolic and fluorescent viability assays. Repeated passages in sub-minimum inhibitory concentration levels did not lead to resistant Candida, in contrast to fluconazole. Our results demonstrate the proof-of principle for the use of these compounds as anti-Candida agents, and their further testing is warranted as novel anti-Candida therapies.

  17. Activity of Antimicrobial Peptide Mimetics in the Oral Cavity: I. Activity Against Biofilms of Candida albicans

    PubMed Central

    Hua, Jianyuan; Yamarthy, Radha; Felsenstein, Shaina; Scott, Richard W.; Markowitz, Kenneth; Diamond, Gill

    2010-01-01

    Summary Naturally occurring antimicrobial peptides hold promise as therapeutic agents against oral pathogens such as Candida albicans, however numerous difficulties have slowed their development. Synthetic, non-peptidic analogs that mimic the properties of these peptides have many advantages and exhibit potent, selective antimicrobial activity. Several series of mimetics (MW <1,000) were developed and screened against oral Candida strains as a proof-of-principle for their antifungal properties. One phenylalkyne and several arylamide compounds with reduced mammalian cytotoxicities were found to be active against C. albicans. These compounds demonstrated rapid fungicidal activity in liquid culture even in the presence of saliva, and demonstrated synergy with standard antifungal agents. When assayed against biofilms grown on denture acrylic, the compounds exhibited potent fungicidal activity as measured by metabolic and fluorescent viability assays. Repeated passages in sub-MIC levels did not lead to resistant Candida in contrast to fluconazole. Our results demonstrate the proof-of principle for the use of these compounds as anti-Candida agents, and their further testing is warranted as novel anti-Candida therapies. PMID:21040515

  18. Comparison of Switching and Biofilm Formation between MTL-Homozygous Strains of Candida albicans and Candida dubliniensis.

    PubMed

    Pujol, Claude; Daniels, Karla J; Soll, David R

    2015-12-01

    Candida albicans and Candida dubliniensis are highly related species that share the same main developmental programs. In C. albicans, it has been demonstrated that the biofilms formed by strains heterozygous and homozygous at the mating type locus (MTL) differ functionally, but studies rarely identify the MTL configuration. This becomes a particular problem in studies of C. dubliniensis, given that one-third of natural strains are MTL homozygous. For that reason, we have analyzed MTL-homozygous strains of C. dubliniensis for their capacity to switch from white to opaque, the stability of the opaque phenotype, CO2 induction of switching, pheromone induction of adhesion, the effects of minority opaque cells on biofilm thickness and dry weight, and biofilm architecture in comparison with C. albicans. Our results reveal that C. dubliniensis strains switch to opaque at lower average frequencies, exhibit a far lower level of opaque phase stability, are not stimulated to switch by high CO2, exhibit more variability in biofilm architecture, and most notably, form mature biofilms composed predominately of pseudohyphae rather than true hyphae. Therefore, while several traits of MTL-homozygous strains of C. dubliniensis appear to be degenerating or have been lost, others, most notably several related to biofilm formation, have been conserved. Within this context, the possibility is considered that C. dubliniensis is transitioning from a hypha-dominated to a pseudohypha-dominated biofilm and that aspects of C. dubliniensis colonization may provide insights into the selective pressures that are involved.

  19. Clusters of patients with candidaemia due to genotypes of Candida albicans and Candida parapsilosis: differences in frequency between hospitals.

    PubMed

    Marcos-Zambrano, L J; Escribano, P; Sanguinetti, M; Gómez G de la Pedrosa, E; De Carolis, E; Vella, A; Cantón, R; Bouza, E; Guinea, J

    2015-07-01

    The presence of clusters (identical genotypes infecting different patients) suggests patient-to-patient transmission or a common source for strains. We report the results of a genotyping study based on microsatellite markers of Candida albicans (n = 179) and Candida parapsilosis (n = 76) causing candidaemia, to assess and compare the percentage of patients grouped in clusters during the study period (January 2010 to December 2012). The study was performed in two large tertiary hospitals in Madrid, Spain. We detected 145 C. albicans genotypes (21 in clusters) and 63 C. parapsilosis genotypes (seven in clusters). Clusters involved two to seven patients each. Most of the clusters in the two centres involved two patients for both species, but the number of patients included in each cluster differed between hospitals. Considering both species, the percentage of patients per cluster ranged from 19% to 38% (p < 0.05) in Hospital A and B respectively. Up to 2.9% of genotypes were present in both hospitals. Clusters of C. albicans and C. parapsilosis genotypes causing candidaemia differed between hospitals, suggesting differences in strain transmission. Occasionally, the same genotypes were found in patients admitted to different hospitals located in the same city.

  20. Piperazinyl quinolines as chemosensitizers to increase fluconazole susceptibility of Candida albicans clinical isolates.

    PubMed

    Youngsaye, Willmen; Vincent, Benjamin; Hartland, Cathy L; Morgan, Barbara J; Buhrlage, Sara J; Johnston, Stephen; Bittker, Joshua A; MacPherson, Lawrence; Dandapani, Sivaraman; Palmer, Michelle; Whitesell, Luke; Lindquist, Susan; Schreiber, Stuart L; Munoz, Benito

    2011-09-15

    The effectiveness of the potent antifungal drug fluconazole is being compromised by the rise of drug-resistant fungal pathogens. While inhibition of Hsp90 or calcineurin can reverse drug resistance in Candida, such inhibitors also impair the homologous human host protein and fungal-selective chemosensitizers remain rare. The MLPCN library was screened to identify compounds that selectively reverse fluconazole resistance in a Candida albicans clinical isolate, while having no antifungal activity when administered as a single agent. A piperazinyl quinoline was identified as a new small-molecule probe (ML189) satisfying these criteria.

  1. [Killer toxin and enzyme production by Candida albicans isolated from buccal mucosa in patients with cancer].

    PubMed

    de Oliveira, E E; Silva, S C; Soares, A J; Attux, C; Cruvinel, B; Silva, M do R

    1998-01-01

    Opportunistic infections of the oral cavity are primarily caused by Candida and frequently occur in patients with cancer who are undergoing chemotherapy and antibiotic treatment. Of the specimens received from the oral mucosa of 44 patients with cancer, 25 (56.8%) yielded Candida on culture in Sabouraud agar. Twenty four of these isolates were identified as C. albicans (96%) and 1 as C. krusei (4%). The phenotypic characteristics of these isolates showed that all of them were strongly proteolytic, had a high ability to produce phospholipase, and presented the byotypes characterized as 811 (95.8%) and 511 (4.2%) in terms of susceptibility to killer toxins. PMID:9859695

  2. Effects of Chitosan on Candida albicans: Conditions for Its Antifungal Activity

    PubMed Central

    Peña, Antonio; Sánchez, Norma Silvia; Calahorra, Martha

    2013-01-01

    The effects of low molecular weight (96.5 KDa) chitosan on the pathogenic yeast Candida albicans were studied. Low concentrations of chitosan, around 2.5 to 10 μg·mL−1 produced (a) an efflux of K+ and stimulation of extracellular acidification, (b) an inhibition of Rb+ uptake, (c) an increased transmembrane potential difference of the cells, and (d) an increased uptake of Ca2+. It is proposed that these effects are due to a decrease of the negative surface charge of the cells resulting from a strong binding of the polymer to the cells. At higher concentrations, besides the efflux of K+, it produced (a) a large efflux of phosphates and material absorbing at 260 nm, (b) a decreased uptake of Ca2+, (c) an inhibition of fermentation and respiration, and (d) the inhibition of growth. The effects depend on the medium used and the amount of cells, but in YPD high concentrations close to 1 mg·mL−1 are required to produce the disruption of the cell membrane, the efflux of protein, and the growth inhibition. Besides the findings at low chitosan concentrations, this work provides an insight of the conditions required for chitosan to act as a fungistatic or antifungal and proposes a method for the permeabilization of yeast cells. PMID:23844364

  3. Phenotypic Plasticity Regulates Candida albicans Interactions and Virulence in the Vertebrate Host

    PubMed Central

    Mallick, Emily M.; Bergeron, Audrey C.; Jones, Stephen K.; Newman, Zachary R.; Brothers, Kimberly M.; Creton, Robbert; Wheeler, Robert T.; Bennett, Richard J.

    2016-01-01

    Phenotypic diversity is critical to the lifestyles of many microbial species, enabling rapid responses to changes in environmental conditions. In the human fungal pathogen Candida albicans, cells exhibit heritable switching between two phenotypic states, white and opaque, which yield differences in mating, filamentous growth, and interactions with immune cells in vitro. Here, we address the in vivo virulence properties of the two cell states in a zebrafish model of infection. Multiple attributes were compared including the stability of phenotypic states, filamentation, virulence, dissemination, and phagocytosis by immune cells, and phenotypes equated across three different host temperatures. Importantly, we found that both white and opaque cells could establish a lethal systemic infection. The relative virulence of the two cell types was temperature dependent; virulence was similar at 25°C, but at higher temperatures (30 and 33°C) white cells were significantly more virulent than opaque cells. Despite the difference in virulence, fungal burden, and dissemination were similar between cells in the two states. Additionally, both white and opaque cells exhibited robust filamentation during infection and blocking filamentation resulted in decreased virulence, establishing that this program is critical for pathogenesis in both cell states. Interactions between C. albicans cells and immune cells differed between white and opaque states. Macrophages and neutrophils preferentially phagocytosed white cells over opaque cells in vitro, and neutrophils showed preferential phagocytosis of white cells in vivo. Together, these studies distinguish the properties of white and opaque cells in a vertebrate host, and establish that the two cell types demonstrate both important similarities and key differences during infection. PMID:27303374

  4. Phenotypic Consequences of a Spontaneous Loss of Heterozygosity in a Common Laboratory Strain of Candida albicans.

    PubMed

    Ciudad, Toni; Hickman, Meleah; Bellido, Alberto; Berman, Judith; Larriba, Germán

    2016-07-01

    By testing the susceptibility to DNA damaging agents of several Candida albicans mutant strains derived from the commonly used laboratory strain, CAI4, we uncovered sensitivity to methyl methanesulfonate (MMS) in CAI4 and its derivatives, but not in CAF2-1. This sensitivity is not a result of URA3 disruption because the phenotype was not restored after URA3 reintroduction. Rather, we found that homozygosis of a short region of chromosome 3R (Chr3R), which is naturally heterozygous in the MMS-resistant-related strains CAF4-2 and CAF2-1, confers MMS sensitivity and modulates growth polarization in response to MMS. Furthermore, induction of homozygosity in this region in CAF2-1 or CAF4-2 resulted in MMS sensitivity. We identified 11 genes by SNP/comparative genomic hybridization containing only the a alleles in all the MMS-sensitive strains. Four candidate genes, SNF5, POL1, orf19.5854.1, and MBP1, were analyzed by generating hemizygous configurations in CAF2-1 and CAF4-2 for each allele of all four genes. Only hemizygous MBP1a/mbp1b::SAT1-FLIP strains became MMS sensitive, indicating that MBP1a in the homo- or hemizygosis state was sufficient to account for the MMS-sensitive phenotype. In yeast, Mbp1 regulates G1/S genes involved in DNA repair. A second region of homozygosis on Chr2L increased MMS sensitivity in CAI4 (Chr3R homozygous) but not CAF4-2 (Chr3R heterozygous). This is the first example of sign epistasis in C. albicans.

  5. Etiological significance of Candida albicans in otitis externa.

    PubMed

    Jadhav, Vijay J; Pal, M; Mishra, G S

    2003-01-01

    A study covering 79 patients (42 males, 37 females) of different age groups clinically diagnosed as otomycosis were investigated mycologically to elucidate the role of Candia albicans, an opportunistic polymorphic yeast, in otitis externa. C. albicans was diagnosed as the sole pathogen in two patients (1 male and 1 female) aged 18 and 20 years, respectively. The organism was repeatedly demonstrated in the aural specimens both by direct microscopy as well as culture isolation. Both the patients had unilateral otomycosis and used antibiotic solution and removed wax with wooden stick. The topical application of one per cent clotrimazole lotion showed good response both clinically as well as mycologically. The growing significance of opportunistic fungi emphasizes on comprehensive studies to establish the etiologic role in various clinical disorders in human and animal medicine.

  6. Antibacterial and antifungal activity of Iranian propolis against Staphylococcus aureus and Candida albicans.

    PubMed

    Ghasem, Yousef-Beigi; Ownagh, Abdolghaffar; Hasanloei, M

    2007-04-15

    Propolis samples from West North region of Iran were studied for their antibacterial (against Staphylococcus aureus) and antifungal (against Candida albicans) activities. In this article, yield of extracts and their pH values were measured. Antibacterial and antifungal activities of Ethanol-Extracted Propolis (EEP) were investigated by Petri dish bioassay method. Dilutions of EPP in agar with serial concentrations ranging from 0/04 to 10% (W/V) were prepared and antimicrobial activities were determined as Minimal Inhibitory Concentrations (MIC). All samples were active against the fungal and bacterial test strains. MIC values for different propolis samples against Staphylococcus aureus were, respectively 4, 3 and 1.5% (W/V) and against Candida albicans were, respectively 2, 4 and 3% (W/V).

  7. Antifungal Activity of Bee Venom and Sweet Bee Venom against Clinically Isolated Candida albicans

    PubMed Central

    Lee, Seung-Bae

    2016-01-01

    Objectives: The purpose of this study was to investigate the antifungal effect of bee venom (BV) and sweet bee venom (SBV) against Candida albicans (C. albicans) clinical isolates. Methods: In this study, BV and SBV were examined for antifungal activities against the Korean Collection for Type Cultures (KCTC) strain and 10 clinical isolates of C. albicans. The disk diffusion method was used to measure the antifungal activity and minimum inhibitory concentration (MIC) assays were performed by using a broth microdilution method. Also, a killing curve assay was conducted to investigate the kinetics of the anti- fungal action. Results: BV and SBV showed antifungal activity against 10 clinical isolates of C. albicans that were cultured from blood and the vagina by using disk diffusion method. The MIC values obtained for clinical isolates by using the broth microdilution method varied from 62.5 μg/ mL to 125 μg/mL for BV and from 15.63 μg/mL to 62.5 μg/mL for SBV. In the killing-curve assay, SBV behaved as amphotericin B, which was used as positive control, did. The antifungal efficacy of SBV was much higher than that of BV. Conclusion: BV and SBV showed antifungal activity against C. albicans clinical strains that were isolated from blood and the vagina. Especially, SBV might be a candidate for a new antifungal agent against C. albicans clinical isolates. PMID:27280049

  8. Occurrence ofCandida albicans in fresh gull feces in temperate and subtropical areas.

    PubMed

    Buck, J D

    1983-07-01

    The occurrence ofCandida albicans in fresh gull (Larus spp.) feces was compared in temperate and subtropical locations. Of 239 fresh samples, 133 were obtained in southeastern Connecticut and 106 from different sites on the southeastern and central western coasts of Florida. Overall, 60% of all feces containedC. albicans. Of the Connecticut samples, 78% were positive, whereas 38% of the Florida samples revealed the presence of the yeast. Only 1 of 24 samples of fresh brown pelican feces containedC. albicans. Differences inC. albicans occurrence in birds in various locations was ascribed to variations in habitat and feeding behavior. Samples of water from a municipal reservoir in Connecticut were routinely positive, with an average cell density of 20/liter. Two fresh gull samples obtained on the reservoir bank containedC. albicans at an average cell concentration of 5, 200/g. The frequency ofC. albicans in gull droppings was higher than reported by others, and the yeast is common in temperate waters. These findings have important public health implications. PMID:24221652

  9. Potent Synergy between Spirocyclic Pyrrolidinoindolinones and Fluconazole against Candida albicans

    PubMed Central

    Premachandra, Ilandari Dewage Udara Anulal; Scott, Kevin A.; Shen, Chengtian; Wang, Fuqiang; Lane, Shelley; Liu, Haoping

    2015-01-01

    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 C. albicans. A diastereomer of that 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, enhanced the effect of fluconazole with EC50 of 300 pM against a susceptible strain of C. albicans and 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 the antifungal synergy. PMID:26263912

  10. Members of the Candida parapsilosis Complex and Candida albicans are Differentially Recognized by Human Peripheral Blood Mononuclear Cells

    PubMed Central

    Estrada-Mata, Eine; Navarro-Arias, María J.; Pérez-García, Luis A.; Mellado-Mojica, Erika; López, Mercedes G.; Csonka, Katalin; Gacser, Attila; Mora-Montes, Héctor M.

    2016-01-01

    The systemic infections caused by members of the Candida parapsilosis complex are currently associated to high morbility and mortality rates, and are considered as relevant as those caused by Candida albicans. Since the fungal cell wall is the first point of contact with the host cells, here we performed a comparison of this organelle in members of the C. parapsilosis complex, and its relevance during interaction with human peripheral blood mononuclear cells (PBMCs). We found that the wall of the C. parapsilosis complex members is similar in composition, but differs to that from C. albicans, with less mannan content and more β-glucan and porosity levels. Furthermore, lectin-based analysis showed increased chitin and β1,3-glucan exposure at the surface of C. parapsilosis sensu lato when compared to C. albicans. Yeast cells of members of the C. parapsilosis complex stimulated more cytokine production by human PBMCs than C. albicans cells; and this significantly changed upon removal of O-linked mannans, indicating this wall component plays a significant role in cytokine stimulation by C. parapsilosis sensu lato. When inner wall components were exposed on the wall surface, C. parapsilosis sensu stricto and C. metapsilosis, but not C. orthopsilosis, stimulated higher cytokine production. Moreover, we found a strong dependency on β1,3-glucan recognition for the members of the C. parapsilosis complex, but not for live C. albicans cells; whereas TLR4 was required for TNFα production by the three members of the complex, and stimulation of IL-6 by C. orthopsilosis. Mannose receptor had a significant role during TNFα and IL-1β stimulation by members of the complex. Finally, we demonstrated that purified N- and O-mannans from either C. parapsilosis sensu lato or C. albicans are capable to block the recognition of these pathogens by human PBMCs. Together; our results suggest that the innate immune recognition of the members of the C. parapsilosis complex is differential

  11. Mixed Fungal Lung Infection with Aspergillus Fumigatus and Candida Albicans in a Immunocomprimised Patient: Case Report

    PubMed Central

    Vipparti, Haritha

    2014-01-01

    The frequency of invasive, opportunistic mycoses has increased significantly over the past 2 decades. In the immune-compromised host, many fungi, including species of fungi typically considered non-pathogenic, have the potential to cause serious morbidity and mortality. Here we report a rare case of mixed fungal infection of the lung with Candida albicans and Aspergillus fumigatus in a patient on prolonged steroid therapy. PMID:24959447

  12. Candida albicans blastoconidia in peripheral blood smears from non-neutropenic surgical patients.

    PubMed

    Berrouane, Y; Bisiau, H; Le Baron, F; Cattoen, C; Duthilleul, P; Dei Cas, E

    1998-07-01

    An 80 year old woman developed fever 11 days after volvulus surgery. A peripheral blood smear showed numerous yeast cells--both extraleucocytic and intraleucocytic--as well as leucoagglutination. The fungal elements included blastospores, pseudohyphae, and germ tubes. Two days later, blood cultures yielded Candida albicans, Enterobacter aerogenes, and Staphlococcus aureus. The patient had no medical history of immunodeficiency. Several reports indicate that fungal elements may be detected in peripheral blood smears from patients who have a severe intestinal disease.

  13. ML212: A small-molecule probe for investigating fluconazole resistance mechanisms in Candida albicans

    PubMed Central

    Youngsaye, Willmen; Hartland, Cathy L; Morgan, Barbara J; Ting, Amal; Nag, Partha P; Vincent, Benjamin; Mosher, Carrie A; Bittker, Joshua A; Dandapani, Sivaraman; Palmer, Michelle; Whitesell, Luke; Lindquist, Susan; Schreiber, Stuart L

    2013-01-01

    Summary The National Institutes of Health Molecular Libraries and Probe Production Centers Network (NIH-MLPCN) screened >300,000 compounds to evaluate their ability to restore fluconazole susceptibility in resistant Candida albicans isolates. Additional counter screens were incorporated to remove substances inherently toxic to either mammalian or fungal cells. A substituted indazole possessing the desired bioactivity profile was selected for further development, and initial investigation of structure–activity relationships led to the discovery of ML212. PMID:23946849

  14. Ultrastructure of Candida albicans pleomorphic forms: phase-contrast microscopy, scanning and transmission electron microscopy.

    PubMed

    Staniszewska, Monika; Bondaryk, Małgorzata; Siennicka, Katarzyna; Kurzatkowski, Wiesław

    2012-01-01

    A modified method of glutaraldeyde-osmium tetroxide fixation was adjusted to characterize the ultrastructure of Candida albicans pleomorphic forms, using phase-contrast microscopy, scanning electron microscopy and transmission electron microscopy. The discovered morphological criteria defining the individual morphotypes are discussed in terms of mycological and histopathological diagnostics of candidiasis. The relations are discussed between fungal pleomorphism, virulence and susceptibility of different morphotypes to fungicides.

  15. Suppression of humoral response during the course of Candida albicans infection in mice.

    PubMed

    Valdez, J C; Meson, O E; de Valdez, G A; Sirena, A

    1984-10-30

    This paper aims at demonstrating the non-specific immunosuppression as regards thyme-dependent antigens sheep erythrocytes (SRBC) during the course of Candida albicans systemic infection. Three lots of syngeneic/BALB/c mice, 8-12 weeks of age, were used. The first normal lot was inoculated via the intraperitoneal route with a (SRBC) suspension (4 X 10(8) cells ml) in a Hank's balanced saline solution. The primary response of antibodies formed by splenic cells was measured from 4 to 8 days after inoculation using the direct plaque forming cells technique. The second lot was infected by the same route with a suspension of Candida albicans (1 X 10(7) cells). Positive retrocultures from the blood and kidneys of these infected mice were obtained. These yeasts cultivated in a Sabouraud medium were harvested after 20 h at 37 degrees C. Following the same methodology the immune response to SRBC was determined. The serum obtained from infected mice was transferred to a third lot of mice at different intervals during the course of the infection. The immune response to SRBC was done by the direct plaque-forming cells technique. Controls were carried out using normal donors and recipients. A suppression of the immune response was obtained as from the 2nd day of inoculation up to the 28th day. It was not possible to transfer such suppression passively by means of the serum. These results suggest that the systemic infection by Candida albicans induce a non-specific immunosuppression in the organism, already demonstrated in viral infections, bacteria, protozoaria and metazoaria in mammals. In some way, this will contribute to explain the mechanisms of immune response to Candida albicans.

  16. Ibuprofen potentiates the in vivo antifungal activity of fluconazole against Candida albicans murine infection.

    PubMed

    Costa-de-Oliveira, Sofia; Miranda, Isabel M; Silva-Dias, Ana; Silva, Ana P; Rodrigues, Acácio G; Pina-Vaz, Cidália

    2015-07-01

    Candida albicans is the most prevalent cause of fungemia worldwide. Its ability to develop resistance in patients receiving azole antifungal therapy is well documented. In a murine model of systemic infection, we show that ibuprofen potentiates fluconazole antifungal activity against a fluconazole-resistant strain, drastically reducing the fungal burden and morbidity. The therapeutic combination of fluconazole with ibuprofen may constitute a new approach for the management of antifungal therapeutics to reverse the resistance conferred by efflux pump overexpression.

  17. Suppression of humoral response during the course of Candida albicans infection in mice.

    PubMed

    Valdez, J C; Meson, O E; de Valdez, G A; Sirena, A

    1984-10-30

    This paper aims at demonstrating the non-specific immunosuppression as regards thyme-dependent antigens sheep erythrocytes (SRBC) during the course of Candida albicans systemic infection. Three lots of syngeneic/BALB/c mice, 8-12 weeks of age, were used. The first normal lot was inoculated via the intraperitoneal route with a (SRBC) suspension (4 X 10(8) cells ml) in a Hank's balanced saline solution. The primary response of antibodies formed by splenic cells was measured from 4 to 8 days after inoculation using the direct plaque forming cells technique. The second lot was infected by the same route with a suspension of Candida albicans (1 X 10(7) cells). Positive retrocultures from the blood and kidneys of these infected mice were obtained. These yeasts cultivated in a Sabouraud medium were harvested after 20 h at 37 degrees C. Following the same methodology the immune response to SRBC was determined. The serum obtained from infected mice was transferred to a third lot of mice at different intervals during the course of the infection. The immune response to SRBC was done by the direct plaque-forming cells technique. Controls were carried out using normal donors and recipients. A suppression of the immune response was obtained as from the 2nd day of inoculation up to the 28th day. It was not possible to transfer such suppression passively by means of the serum. These results suggest that the systemic infection by Candida albicans induce a non-specific immunosuppression in the organism, already demonstrated in viral infections, bacteria, protozoaria and metazoaria in mammals. In some way, this will contribute to explain the mechanisms of immune response to Candida albicans. PMID:6392889

  18. Ibuprofen Potentiates the In Vivo Antifungal Activity of Fluconazole against Candida albicans Murine Infection

    PubMed Central

    Miranda, Isabel M.; Silva-Dias, Ana; Silva, Ana P.; Rodrigues, Acácio G.; Pina-Vaz, Cidália

    2015-01-01

    Candida albicans is the most prevalent cause of fungemia worldwide. Its ability to develop resistance in patients receiving azole antifungal therapy is well documented. In a murine model of systemic infection, we show that ibuprofen potentiates fluconazole antifungal activity against a fluconazole-resistant strain, drastically reducing the fungal burden and morbidity. The therapeutic combination of fluconazole with ibuprofen may constitute a new approach for the management of antifungal therapeutics to reverse the resistance conferred by efflux pump overexpression. PMID:25845879

  19. Design and Evaluation of Peptide Nucleic Acid Probes for Specific Identification of Candida albicans

    PubMed Central

    Kim, Hyun-Joong

    2014-01-01

    Candida albicans is an important cause of systemic fungal infections, and rapid diagnostics for identifying and differentiating C. albicans from other Candida species are critical for the timely application of appropriate antimicrobial therapy, improved patient outcomes, and pharmaceutical cost savings. In this work, two 28S rRNA-directed peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) probes, P-Ca726 (targeting a novel region of the ribosome) and P-CalB2208 (targeting a previously reported region), were evaluated. Hybridization conditions were optimized by using both fluorescence microscopy (FM) and flow cytometry (FCM), and probes were screened for specificity and discriminative ability against a panel of C. albicans and various nontarget Candida spp. The performance of these PNA probes was compared quantitatively against that of DNA probes or DNA probe/helper combinations directed against the same target regions. Ratiometric analyses of FCM results indicated that both the hybridization quality and yield of the PNA probes were higher than those of the DNA probes. In FCM-based comparisons of the PNA probes, P-Ca726 was found to be highly specific, showing 2.5- to 5.5-fold-higher discriminatory power for C. albicans than P-CalB2208. The use of formamide further improved the performance of the new probe. Our results reinforce the significant practical and diagnostic advantages of PNA probes over their DNA counterparts for FISH and indicate that P-Ca726 may be used advantageously for the rapid and specific identification of C. albicans in clinical and related applications, especially when combined with FCM. PMID:25428160

  20. Antifungal potential of Sideroxylon obtusifolium and Syzygium cumini and their mode of action against Candida albicans.

    PubMed

    Pereira, Jozinete Vieira; Freires, Irlan Almeida; Castilho, Aline Rogéria; da Cunha, Marcos Guilherme; Alves, Harley da Silva; Rosalen, Pedro Luiz

    2016-10-01

    Context The emergence of resistant pathogens and toxicity of antifungals have encouraged an active search for novel candidates to manage Candida biofilms. Objective In this study, the little known species Sideroxylon obtusifolium T.D. Penn (Sapotacea) and Syzygium cumini (L.) Skeels (Myrtaceae), from the Caatinga biome in Brazil were chemically characterized and explored for their antifungal potential against C. albicans. Materials and methods We determined the effects of hydroalcoholic extracts/fractions upon fungal growth (minimum inhibitory and fungicidal concentrations, MIC/MFC), biofilm morphology (scanning electron microscopy) and viability (confocal laser scanning microscopy), proposed their mode of action (sorbitol and ergosterol assays), and finally investigated their effects against macrophage and keratinocyte cells in a cell-based assay. Data were analysed using one-way analysis of variance with Tukey-Kramer post-test (α = 0.05). Results The n-butanol (Nb) fraction from S. obtusifolium and S. cumini extract (Sc) showed flavonoids (39.11 ± 6.62 mg/g) and saponins (820.35 ± 225.38 mg/g), respectively, in their chemical composition and demonstrated antifungal activity, with MICs of 62.5 and 125 μg/mL, respectively. Nb and Sc may complex with ergosterol as there was a 4-16-fold increase in MICs in the presence of exogenous ergosterol, leading to disrupted permeability of cell membrane. Deleterious effects were observed on morphology and viability of treated biofilms from concentrations as low as their MICs and higher. Sc was not toxic to macrophages and keratinocytes at these concentrations (p > 0.05), unlike Nb. Conclusions Nb and Sc demonstrated considerable antifungal activity and should be further investigated as potential alternative candidates to treat Candida biofilms. PMID:26987037

  1. The Role of Isocitrate Lyase (ICL1) in the Metabolic Adaptation of Candida albicans Biofilms

    PubMed Central

    Ishola, Oluwaseun Ayodeji; Ting, Seng Yeat; Tabana, Yasser M; Ahmed, Mowaffaq Adam; Yunus, Muhammad Amir; Mohamed, Rafeezul; Lung Than, Leslie Thian; Sandai, Doblin

    2016-01-01

    Background A major characteristic of Candida biofilm cells that differentiates them from free-floating cells is their high tolerance to antifungal drugs. This high resistance is attributed to particular biofilm properties, including the accumulation of extrapolymeric substances, morphogenetic switching, and metabolic flexibility. Objectives This study evaluated the roles of metabolic processes (in particular the glyoxylate cycle) on biofilm formation, antifungal drug resistance, morphology, and cell wall components. Methods Growth, adhesion, biofilm formation, and cell wall carbohydrate composition were quantified for isogenic Candida albicans ICL1/ICL1, ICL1/icl1, and icl1/icl1 strains. The morphology and topography of these strains were compared by light microscopy and scanning electron microscopy. FKS1 (glucan synthase), ERG11 (14-α-demethylase), and CDR2 (efflux pump) mRNA levels were quantified using qRT-PCR. Results The ICL1/icl1 and icl1/icl1 strains formed similar biofilms and exhibited analogous drug-tolerance levels to the control ICL1/ICL1 strains. Furthermore, the drug sequestration ability of β-1, 3-glucan, a major carbohydrate component of the extracellular matrix, was not impaired. However, the inactivation of ICL1 did impair morphogenesis. ICL1 deletion also had a considerable effect on the expression of the FKS1, ERG11, and CDR2 genes. FKS1 and ERG11 were upregulated in ICL1/icl1 and icl1/icl1 cells throughout the biofilm developmental stages, and CDR2 was upregulated at the early phase. However, their expression was downregulated compared to the control ICL1/ICL1 strain. Conclusions We conclude that the glyoxylate cycle is not a specific determinant of biofilm drug resistance. PMID:27800147

  2. Manipulation of Host Diet To Reduce Gastrointestinal Colonization by the Opportunistic Pathogen Candida albicans

    PubMed Central

    Tornberg-Belanger, Stephanie N.; Matthan, Nirupa R.; Lichtenstein, Alice H.

    2015-01-01

    ABSTRACT Candida albicans, the most common human fungal pathogen, can cause systemic infections with a mortality rate of ~40%. Infections arise from colonization of the gastrointestinal (GI) tract, where C. albicans is part of the normal microflora. Reducing colonization in at-risk patients using antifungal drugs prevents C. albicans-associated mortalities. C. albicans provides a clinically relevant system for studying the relationship between diet and the microbiota as it relates to commensalism and pathogenicity. As a first step toward a dietary intervention to reduce C. albicans GI colonization, we investigated the impact of dietary lipids on murine colonization by C. albicans. Coconut oil and its constituent fatty acids have antifungal activity in vitro; we hypothesized that dietary coconut oil would reduce GI colonization by C. albicans. Colonization was lower in mice fed a coconut oil-rich diet than in mice fed diets rich in beef tallow or soybean oil. Switching beef tallow-fed mice to a coconut oil diet reduced preexisting colonization. Coconut oil reduced colonization even when the diet also contained beef tallow. Dietary coconut oil also altered the metabolic program of colonizing C. albicans cells. Long-chain fatty acids were less abundant in the cecal contents of coconut oil-fed mice than in the cecal contents of beef tallow-fed mice; the expression of genes involved in fatty acid utilization was lower in C. albicans from coconut oil-fed mice than in C. albicans from beef tallow-fed mice. Extrapolating to humans, these findings suggest that coconut oil could become the first dietary intervention to reduce C. albicans GI colonization. IMPORTANCE Candida albicans, the most common human fungal pathogen, can cause infections with a mortality rate of ~40%. C. albicans is part of the normal gut flora, but when a patient’s immune system is compromised, it can leave the gut and cause infections. By reducing the amount of C. albicans in the gut of

  3. Manipulation of Host Diet To Reduce Gastrointestinal Colonization by the Opportunistic Pathogen Candida albicans.

    PubMed

    Gunsalus, Kearney T W; Tornberg-Belanger, Stephanie N; Matthan, Nirupa R; Lichtenstein, Alice H; Kumamoto, Carol A

    2016-01-01

    Candida albicans, the most common human fungal pathogen, can cause systemic infections with a mortality rate of ~40%. Infections arise from colonization of the gastrointestinal (GI) tract, where C. albicans is part of the normal microflora. Reducing colonization in at-risk patients using antifungal drugs prevents C. albicans-associated mortalities. C. albicans provides a clinically relevant system for studying the relationship between diet and the microbiota as it relates to commensalism and pathogenicity. As a first step toward a dietary intervention to reduce C. albicans GI colonization, we investigated the impact of dietary lipids on murine colonization by C. albicans. Coconut oil and its constituent fatty acids have antifungal activity in vitro; we hypothesized that dietary coconut oil would reduce GI colonization by C. albicans. Colonization was lower in mice fed a coconut oil-rich diet than in mice fed diets rich in beef tallow or soybean oil. Switching beef tallow-fed mice to a coconut oil diet reduced preexisting colonization. Coconut oil reduced colonization even when the diet also contained beef tallow. Dietary coconut oil also altered the metabolic program of colonizing C. albicans cells. Long-chain fatty acids were less abundant in the cecal contents of coconut oil-fed mice than in the cecal contents of beef tallow-fed mice; the expression of genes involved in fatty acid utilization was lower in C. albicans from coconut oil-fed mice than in C. albicans from beef tallow-fed mice. Extrapolating to humans, these findings suggest that coconut oil could become the first dietary intervention to reduce C. albicans GI colonization. IMPORTANCE Candida albicans, the most common human fungal pathogen, can cause infections with a mortality rate of ~40%. C. albicans is part of the normal gut flora, but when a patient's immune system is compromised, it can leave the gut and cause infections. By reducing the amount of C. albicans in the gut of susceptible

  4. Eugenol and thymol, alone or in combination, induce morphological alterations in the envelope of Candida albicans.

    PubMed

    Braga, P C; Sasso, M Dal; Culici, M; Alfieri, M

    2007-09-01

    The envelope of Candida albicans, with its outermost array of macromolecules protruding towards the environment, is pivotal to the expression of major virulence factors such as adhesiveness, and the morphological transition to hyphal form. We tested the anticandidal activity of eugenol, main component of clove oil, and thymol, main component of thyme oil, alone or in combination, by investigating their ability to interfere with the architecture of the envelope of C. albicans. Both molecules alterated the morphogenesis of the envelope, but the effects of thymol were more pronounced than those of eugenol. Certain combinations of the two molecules led to a synergistic effect, which is interesting in the view of potentiating their inhibition of C. albicans colonisation and infectiousness. PMID:17590533

  5. Oral Immunization Against Candidiasis Using Lactobacillus casei Displaying Enolase 1 from Candida albicans

    PubMed Central

    Shibasaki, Seiji; Karasaki, Miki; Tafuku, Senji; Aoki, Wataru; Sewaki, Tomomitsu; Ueda, Mitsuyoshi

    2014-01-01

    Abstract Candidiasis is a common fungal infection that is prevalent in immunocompromised individuals. In this study, an oral vaccine against Candida albicans was developed by using the molecular display approach. Enolase 1 protein (Eno1p) of C. albicans was expressed on the Lactobacillus casei cell surface by using poly-gamma-glutamic acid synthetase complex A from Bacillus subtilis as an anchoring protein. The Eno1p-displaying L. casei cells were used to immunize mice, which were later challenged with a lethal dose of C. albicans. The data indicated that the vaccine elicited a strong IgG response and increased the survival rate of the vaccinated mice. Furthermore, L. casei acted as a potent adjuvant and induced high antibody titers that were comparable to those induced by strong adjuvants such as the cholera toxin. Overall, the molecular display method can be used to rapidly develop vaccines that can be conveniently administered and require minimal processing. PMID:25853077

  6. The Role of Autophagy-Related Proteins in Candida albicans Infections

    PubMed Central

    Tam, Jenny M.; Mansour, Michael K.; Acharya, Mridu; Sokolovska, Anna; Timmons, Allison K.; Lacy-Hulbert, Adam; Vyas, Jatin M.

    2016-01-01

    Autophagy plays an important role in maintaining cell homeostasis by providing nutrients during periods of starvation and removing damaged organelles from the cytoplasm. A marker in the autophagic process is the reversible conjugation of LC3, a membrane scaffolding protein, to double membrane autophagosomes. Recently, a role for LC3 in the elimination of pathogenic bacteria and fungi, including Candida albicans (C. albicans), was demonstrated, but these organisms reside in single membrane phagosomes. This process is distinct from autophagy and is termed LC3-associated phagocytosis (LAP). This review will detail the hallmarks of LAP that distinguish it from classical autophagy and review the role of autophagy proteins in host response to C. albicans and other pathogenic fungi. PMID:27043636

  7. Protocol for Determination of the Persister Subpopulation in Candida Albicans Biofilms.

    PubMed

    De Brucker, Katrijn; De Cremer, Kaat; Cammue, Bruno P A; Thevissen, Karin

    2016-01-01

    In contrast to planktonic cultures of the human fungal pathogen Candida albicans, C. albicans biofilms can contain a persister subpopulation that is tolerant to high concentrations of currently used antifungals. In this chapter, the method to determine the persister fraction in a C. albicans biofilm treated with an antifungal compound is described. To this end, a mature biofilm is developed and subsequently treated with a concentration series of the antifungal compound of interest. Upon incubation, the fraction of surviving biofilm cells is determined by plating and plotted versus the used concentrations of the antifungal compound. If a persister subpopulation in the biofilm is present, the dose-dependent killing of the biofilm cells results in a biphasic killing pattern.

  8. Acute labyrinthitis associated with systemic Candida albicans infection in ageing mice.

    PubMed

    Ashman, R B; Papadimitriou, J M; Fulurija, A

    1996-01-01

    The yeast Candida albicans is an important opportunistic pathogen that has been associated with disease of the inner ear. This study describes the histopathology of acute labyrinthitis caused by systemic infection with C. albicans in aging inbred mice. Within four days after infection, yeast and hyphal forms of C.albicans were found in the membranous labyrinth. The utricle and the adjacent parts of the ampullary regions of the semicircular canals were most severely affected, but damage was also seen in the scala media, the scala tympani, the saccule, and the scala vestibuli. In the utricle, the lining epithelium of the membranous labyrinth was disrupted, and the lining cells of the vestibular membrane showed foci in which the membrane was disrupted. The data suggest that age may represent a risk factor for fungal labyrinthitis.

  9. Modulation of Candida albicans attachment to human epithelial cells by bacteria and carbohydrates.

    PubMed Central

    Centeno, A; Davis, C P; Cohen, M S; Warren, M M

    1983-01-01

    The effects of carbohydrates (mannose and dextrose). Escherichia coli 07KL. and Klebsiella pneumoniae on Candida albicans attachment to epithelial cells was studied. Dextrose had no effect on yeast attachment to epithelial cells. Conversely, mannose significantly decreased both yeast and piliated bacterial attachment (E. coli 07KL, heavily piliated K. pneumoniae) whereas having no effect on nonpiliated K. pneumoniae attachment to epithelial cells. The number of yeasts attaching to epithelial cells was enhanced by preincubation of epithelial cells with piliated strains of bacteria, whereas preincubation with nonpiliated strains of bacteria had no effect on yeast attachment. Scanning electron microscopy showed that piliated bacteria and yeasts were juxtaposed on the epithelial cell surface. These data suggest that certain piliated strains of bacteria can enhance C. albicans attachment to epithelial cells and that type 1 pili of bacteria can be a factor in the enhanced attachment of C. albicans to epithelial cells. Images PMID:6132878

  10. Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin.

    PubMed

    Sousa, Fernando Augusto Cervantes Garcia de; Paradella, Thaís Cachuté; Koga-Ito, Cristiane Yumi; Jorge, Antonio Olavo Cardoso

    2009-01-01

    The purpose of this study was to evaluate the effect of 5% sodium bicarbonate on the adherence of Candida albicans to thermally activated acrylic resin. Fifty 4 mm(2) specimens of acrylic resin were obtained using a metallic matrix. The specimens received chemical polishing, were sterilized and then immersed in Sabouraud broth, inoculated with Candida albicans standardized suspension. After 24 hours of incubation at 37 degrees Celsius, the specimens were divided into four groups according to the substance used for disinfection (5% sodium bicarbonate, 0.12% digluconate chlorhexidine, vinegar and Corega Tabs). A control group was included, in which distilled water was used. The adhered microorganisms were dispersed, diluted and plated onto culture media to determine the number of colony-forming units (cfu/mL). The results were analyzed through the Mann-Whitney statistical test at the 5% level of significance. Only 0.12% digluconate chlorhexidine and 5% sodium bicarbonate presented a statistically significant difference (p = 0.0010 and p = 0.0156, respectively) compared to the control group, decreasing the number of cfu/mL. However, when the different disinfecting solutions were compared with each other, only 0.12% digluconate chlorhexidine presented a statistically significant difference in the reduction of cfu/mL. It was concluded that although 0.12% digluconate chlorhexidine was more effective in the reduction of Candida albicans adherence values to thermally activated acrylic resin, 5% sodium bicarbonate also proved to be a viable alternative. PMID:20027444

  11. Analysis of the relationship between fluconazole consumption and non-C. albicans Candida infections.

    PubMed

    Tyczkowska-Sieron, E; Gaszynski, W; Tyczkowski, J; Glowacka, A

    2014-10-01

    The effect of fluconazole consumption on the incidence of nosocomial non-C. albicans Candida infections remains unclear. In this study we investigated such a relationship in an intensive care unit (Poland) over an 11-year period (2002-2012). Statistics relating to the number of candidiasis cases and the number of defined daily doses of fluconazole showed that only a very weak and not statistically significant linear correlation existed between these two variables (r(2) = 0.36, P = 0.052). However, the assumption of a 1-year delay in the infection response to changes in fluconazole concentrations resulted in a strong and statistically significant linear correlation (r(2) = 0.64, P = 0.0053). To more accurately determine the nature of this relationship, a simple epidemiological model was proposed that provided a better than linear correlation (r(2) = 0.78, P = 0.00077). We successfully used this approach to analyze results from the literature that were interpreted as evidence that fluconazole use is not a risk factor for development of non-C. albicans Candida infections. If a time delay in the infection response was assumed, a strong and statistically significant correlation was obtained. These findings suggest the need for a closer look at fluconazole therapy as a possible risk factor for development of non-C. albicans Candida infections.

  12. DLH1 is a functional Candida albicans homologue of the meiosis-specific gene DMC1

    SciTech Connect

    Diener, A.C.; Fink, G.R.

    1996-06-01

    DMC1/LIM15 homologue 1 (DLH1), a gene related to meiosis-specific genes, has been isolated from Candida albicans, a fungus thought not to undergo meiosis. The deduced protein sequence of DLH1 contains 74% amino acid identity with Dmc1p from Saccharomyces cerevisiae and 63% with Lim15p from the plant Lilium longiflorum, meiosis-specific homologous of Escherichia coli RecA. Candida DLH1 complements a dmc1/dmc1 null mutant in S. cerevisiae. High copy expression of DLH1 restores both sporulation and meiotic recombination to a Saccharomyces dmc1/{Delta}/dmc1{Delta} strain. Unlike the DMC1 gene, which is transcribed only in meiotic cells, the heterologous Candida DLH1 gene is transcribed in both vegetative and meiotic cells of S. cerevisiae. Transcription of DLH1 is not detected or induced in C. albicans under conditions that induce DMC1 and meiosis in S. cerevisiae. The presence of an intact homologue of a meiosis-specific gene in C. albicans raises the possibility that this organism has a cryptic meiotic pathway. 25 refs., 6 figs., 3 tabs.

  13. Effect of two monoterpene phenols on antioxidant defense system in Candida albicans.

    PubMed

    Khan, Amber; Ahmad, Aijaz; Ahmad Khan, Luqman; Padoa, Carolyn J; van Vuuren, Sandy; Manzoor, Nikhat

    2015-03-01

    Thymol and carvacrol from the class of monoterpene phenols are one of the most potent plant essential oil components possessing antimicrobial effects. Known for their wide bioactive spectrum, these positional isomers of isopropyl cresol deplete ergosterol content, compromise membrane permeability, block efflux pumps and restore antifungal susceptibility to fluconazole in resistant Candida strains. Exposure to these natural compounds induces a cascade of stress responses, which are important to comprehend their microbicidal mechanisms. This study evaluates the antioxidant defense response to lower concentrations of thymol and carvacrol in Candida albicans. The antioxidant defense responses in C. albicans are important for developmental mechanisms pertaining to resistance against the immune system, infection establishment and drug resistance. In this view, primary and secondary antioxidant defense enzymes, and oxidative stress markers including glutathione and lipid peroxidation were determined in C. albicans cells exposed to lower concentrations of thymol and carvacrol. These compounds were found to induce oxidative stress and compromised the antioxidant defense system in C. albicans at lower concentrations. This study helps in understanding the 'in cell' antifungal mechanisms of natural monoterpene phenols originating from oxidative stress. Thymol and carvacrol induced membrane deterioration reported earlier, is further explained as a result of a toxic radical cascade mediated by lipid peroxidation. Findings reinforce the observed toxic oxidizing effects of these compounds as a consequence of direct damage to antioxidant components and not to their genetic manipulations. PMID:25681060

  14. Effect of serum and surface characteristics on Candida albicans biofilm formation.

    PubMed

    Frade, João Pedro; Arthington-Skaggs, Beth A

    2011-07-01

    Candida spp. biofilms can be established on a wide range of materials, including implanted medical devices, and can display a resistant phenotype to antifungal drugs. Several factors, including host and surface properties, may influence the establishment and the development of Candida albicans biofilms on biotic and abiotic surfaces. We therefore selected a collection of C. albicans clinical isolates to evaluate the effect of surface and serum on biofilm attachment and development. Disc coupons from the CDC biofilm reactor were used in a well plate assay to study biofilm production on six different surfaces with or without the addition of serum: polycarbonate, polystyrene, stainless steel, Teflon, polyvinyl chloride or hydroxyapatite. Our results showed that serum increases in vitro C. albicans biofilm formation on a wide range of distinct surfaces including metallic and non-metallic materials, and that roughness and hydrophobicity can modulate C. albicans biofilm formation. These findings were also confirmed by scanning electron microscopy and it revealed the deposition of extracellular material on hyphae attached to a solid surface. Interestingly, adhesion can be significantly increased in the early stages of colonisation when serum is provided as a conditioning film in a surface-dependent manner.

  15. Application of surface plasmon resonance biosensor for the detection of Candida albicans

    NASA Astrophysics Data System (ADS)

    Yodmongkol, Sirasa; Thaweboon, Sroisiri; Thaweboon, Boonyanit; Puttharugsa, Chokchai; Sutapun, Boonsong; Amarit, Ratthasart; Somboonkaew, Armote; Srikhirin, Toemsak

    2016-02-01

    In this study, surface plasmon resonance imaging (SPR imaging) was developed for the detection of Candida albicans which is a causal agent of oral infection. The detection was based on the sandwich assay. The capture antibody was covalently immobilized on the mixed self assemble monolayers (SAMs). The ratio of mixed SAMs between 11-mercaptoundecanoic acid and 3-mercaptopropanol was varied to find the optimal ratio for use as a sensor surface. The results showed that the suitable surface for C. albicans detection was SAM of carboxylic (mixed SAMs 1:0), even though mixed SAMs 1:40 had a high detection signal in comparison to mixed SAMs 1:0, but the non-specific signal was higher. The detection limit was 107 cells/ml for direct detection, and was increased to 106 cells/ml with sandwich antibody. The use of polyclonal C. albicans antibody as capture and sandwich antibody showed good selectivity against the relevant oral bacteria including Escherichia coli, Streptococcus mutan, Staphylococcus aureus, β-streptococci, and Lactobacillus casei. SPR platform in this study could detect C. albicans from the mixed microbial suspension without requirement of skillful technician. This SPR imaging biosensor could be applied for Candida identification after cultivation.

  16. Nanoscopic cell-wall architecture of an immunogenic ligand in Candida albicans during antifungal drug treatment

    PubMed Central

    Lin, Jia; Wester, Michael J.; Graus, Matthew S.; Lidke, Keith A.; Neumann, Aaron K.

    2016-01-01

    The cell wall of Candida albicans is composed largely of polysaccharides. Here we focus on β-glucan, an immunogenic cell-wall polysaccharide whose surface exposure is often restricted, or “masked,” from immune recognition by Dectin-1 on dendritic cells (DCs) and other innate immune cells. Previous research suggested that the physical presentation geometry of β-glucan might determine whether it can be recognized by Dectin-1. We used direct stochastic optical reconstruction microscopy to explore the fine structure of β-glucan exposed on C. albicans cell walls before and after treatment with the antimycotic drug caspofungin, which alters glucan exposure. Most surface-accessible glucan on C. albicans yeast and hyphae is limited to isolated Dectin-1–binding sites. Caspofungin-induced unmasking caused approximately fourfold to sevenfold increase in total glucan exposure, accompanied by increased phagocytosis efficiency of DCs for unmasked yeasts. Nanoscopic imaging of caspofungin-unmasked C. albicans cell walls revealed that the increase in glucan exposure is due to increased density of glucan exposures and increased multiglucan exposure sizes. These findings reveal that glucan exhibits significant nanostructure, which is a previously unknown physical component of the host–Candida interaction that might change during antifungal chemotherapy and affect innate immune activation. PMID:26792838

  17. Biofilm formation and Candida albicans morphology on the surface of denture base materials.

    PubMed

    Susewind, Sabine; Lang, Reinhold; Hahnel, Sebastian

    2015-12-01

    Fungal biofilms may contribute to the occurrence of denture stomatitis. The objective of the study was to investigate the biofilm formation and morphology of Candida albicans in biofilms on the surface of denture base materials. Specimens were prepared from different denture base materials. After determination of surface properties and salivary pellicle formation, mono- and multispecies biofilm formation including Candida albicans ATCC 10231 was initiated. Relative amounts of adherent cells were determined after 20, 44, 68 and 188 h; C. albicans morphology was analysed employing selective fluorescence microscopic analysis. Significant differences were identified in the relative amount of cells adherent to the denture base materials. Highest blastospore/hyphae index suggesting an increased percentage of hyphae was observed in mono- and multispecies biofilms on the soft denture liner, which did not necessarily respond to the highest relative amount of adherent cells. For both biofilm models, lowest relative amount of adherent cells was identified on the methacrylate-based denture base material, which did not necessarily relate to a significantly lower blastospore/hyphae index. The results indicate that there are significant differences in both biofilm formation as well as the morphology of C. albicans cells in biofilms on the surface of different denture base materials.

  18. Top-down characterization data on the speciation of the Candida albicans immunome in candidemia.

    PubMed

    Pitarch, Aida; Nombela, César; Gil, Concha

    2016-03-01

    The characterization of pathogen-specific antigenic proteins at the protein species level is crucial in the development and molecular optimization of novel immunodiagnostics, vaccines or immunotherapeutics for infectious diseases. The major requirements to achieve this molecular level are to obtain 100% sequence coverage and identify all post-translational modifications of each antigenic protein species. In this article, we show nearly complete sequence information for five discrete antigenic species of Candida albicans Tdh3 (glyceraldehyde-3-phosphate dehydrogenase), which have been reported to be differentially recognized both among candidemia patients and between candidemia and control patients. A comprehensive description of the top-down immunoproteomic strategy used for seroprofiling at the C. albicans protein species level in candidemia as well as for the chemical characterization of this immunogenic protein (based on high-resolution 2-DE, Western blotting, peptide mass fingerprinting, tandem mass spectrometry and de novo peptide sequencing) is also provided. The top-down characterization data on the speciation of the C. albicans immunome in candidemia presented here are related to our research article entitled "Seroprofiling at the Candida albicans protein species level unveils an accurate molecular discriminator for candidemia" (Pitarch et al., J. Proteomics, 2015, http://dx.doi.org/10.1016/j.jprot.2015.10.022). PMID:26862568

  19. Application of benzo[a]phenoxazinium chlorides in Antimicrobial Photodynamic Therapy of Candida albicans biofilms.

    PubMed

    Lopes, Marisa; Alves, Carlos Tiago; Rama Raju, B; Gonçalves, M Sameiro T; Coutinho, Paulo J G; Henriques, Mariana; Belo, Isabel

    2014-12-01

    The use of Antimicrobial Photodynamic Therapy (APDT) as a new approach to treat localized Candida infections is an emerging and promising field nowadays. The aim of this study was to verify the efficacy of photodynamic therapy using two new benzo[a]phenoxazinium photosensitizers against Candida albicans biofilms: N-(5-(3-hydroxypropylamino)-10-methyl-9H-benzo[a]phenoxazin-9-ylidene)ethanaminium chloride (FSc) and N-(5-(11-hydroxyundecylamino)-10-methyl-9H-benzo[a]phenoxazin-9-ylidene)ethanaminium chloride (FSd). The photodynamic activity of dyes against C. albicans biofilms was evaluated by incubating biofilms with dyes in the range of 100-300 μM for 3 or 18 h followed by illumination at 12 or 36 J cm(-2), using a xenon arc lamp (600 ± 2 nm). A total photoinactivation of C. albicans biofilm cells was achieved using 300 μM of FSc with 18 h of incubation, followed by illumination at 36 J cm(-2). Contrarily, FSd had insignificant effect on biofilms inactivation by APDT. The higher uptake of FSc than FSd dye by biofilms during the dark incubation may explain the greater photodynamic effectiveness achieved with FSc. The results obtained stresses out the FSc-mediated APDT potential use to treat C. albicans infections.

  20. The effect of thyme and tea tree oils on morphology and metabolism of Candida albicans.

    PubMed

    Rajkowska, Katarzyna; Kunicka-Styczyńska, Alina; Maroszyńska, Marta; Dąbrowska, Mariola

    2014-01-01

    Members of Candida species cause significant problems in medicine and in many industrial branches also. In order to prevent from Candida sp. development, essential oils are more and more frequently applied as natural, non-toxic, non-pollutive and biodegradable agents with a broad spectrum of antimicrobial activity. The aim of the research was to determine changes in morphology and metabolic properties of Candida albicans in the presence of thyme and tea tree oils. Changes of enzymatic activity of isolates were observed in the presence of both tested essential oils, and they were primarily associated with loss or decrease of activity of all enzymes detected for control. Furthermore, only for 3 out of 11 isolates additional activity of N-acetyl-β-glucosaminidase, α-mannosidase, α-fucosidase and trypsin was detected. Vivid changes in biochemical profiles were found after treatment with tea tree oil and they were related to loss of ability to assimilate D-xylose, D-sorbitol and D-trehalose. The main differences in morphology of isolates compared to the control strain concerned formation of pseudohyphae structures. Both examined essential oils caused changes in cell and colony morphology, as well as in the metabolism of Candida albicans. However, the extent of differences depends on the type and concentration of an essential oil. The most important finding is the broad spectrum of changes in yeast enzymatic profiles induced by thyme and tea tree oils. It can be supposed that these changes, together with loss of ability to assimilate saccharides could significantly impact Candida albicans pathogenicity.

  1. The effect of thyme and tea tree oils on morphology and metabolism of Candida albicans.

    PubMed

    Rajkowska, Katarzyna; Kunicka-Styczyńska, Alina; Maroszyńska, Marta; Dąbrowska, Mariola

    2014-01-01

    Members of Candida species cause significant problems in medicine and in many industrial branches also. In order to prevent from Candida sp. development, essential oils are more and more frequently applied as natural, non-toxic, non-pollutive and biodegradable agents with a broad spectrum of antimicrobial activity. The aim of the research was to determine changes in morphology and metabolic properties of Candida albicans in the presence of thyme and tea tree oils. Changes of enzymatic activity of isolates were observed in the presence of both tested essential oils, and they were primarily associated with loss or decrease of activity of all enzymes detected for control. Furthermore, only for 3 out of 11 isolates additional activity of N-acetyl-β-glucosaminidase, α-mannosidase, α-fucosidase and trypsin was detected. Vivid changes in biochemical profiles were found after treatment with tea tree oil and they were related to loss of ability to assimilate D-xylose, D-sorbitol and D-trehalose. The main differences in morphology of isolates compared to the control strain concerned formation of pseudohyphae structures. Both examined essential oils caused changes in cell and colony morphology, as well as in the metabolism of Candida albicans. However, the extent of differences depends on the type and concentration of an essential oil. The most important finding is the broad spectrum of changes in yeast enzymatic profiles induced by thyme and tea tree oils. It can be supposed that these changes, together with loss of ability to assimilate saccharides could significantly impact Candida albicans pathogenicity. PMID:24918492

  2. Recurrent candidaemia and pacemaker wire infection with Candida albicans.

    PubMed

    Glöckner, A

    2011-12-01

    Recurrent candidaemia is both a cause and a symptom of deep organ candidiasis or infection of foreign bodies (e.g. central venous line, other indwelling catheter or pacemaker wire) and is associated with significant morbidity and mortality. This case report demonstrates that in the event of pacemaker wire infection with Candida and when it is not possible to remove the infected pacemaker wire, treatment with an echinocandin, such as anidulafungin, can be safe and successful.

  3. Photodynamic antimicrobial chemotherapy (PACT) inhibits biofilm formation by Candida albicans, increasing both ROS production and membrane permeability.

    PubMed

    Rosseti, Isabela Bueno; Chagas, Luciene Reginato; Costa, Maricilia Silva

    2014-05-01

    The opportunistic fungal Candida albicans is able to produce both superficial and systemic infections in immunocompromised patients. Photodynamic antimicrobial chemotherapy (PACT) is a process that combines visible light and a photosensitizer, producing reactive oxygen species (ROS) that can kill the treated cells and has been presented as a potential antimicrobial therapy. In this work, we study the effects of PACT, using toluidine blue (TB) as a photosensitizer drug, on ROS production and cell damage and the ability of C. albicans to form biofilm. A significant decrease was observed in the cell growth after PACT in a TB concentration-dependent manner. This effect was dependent on the incubation time after PACT. In addition, an increase in both the ROS production and cell permeability, after PACT, in a TB concentration-dependent manner was observed. PACT, using 0.1 mg/ml TB was able to reduce biofilm formation in 30, 50, and 62%, in cells submitted to incubation times of 1, 2, and 3 h, respectively. These results suggested that PACT, using TB, is able to decrease both growth and biofilm formation by C. albicans, possibly by a mechanism evolving both ROS production and the increase in the cell permeability.

  4. Thiamine antivitamins--an opportunity of therapy of fungal infections caused by Malassezia pachydermatis and Candida albicans.

    PubMed

    Siemieniuk, Magdalena; Czyzewska, Urszula; Strumilo, Slawomir; Tylicki, Adam

    2016-02-01

    Severe skin diseases and systemic fungaemia are caused by Malassezia pachydermatis and Candida albicans respectively. Antifungal therapies are less effective because of chronic character of infections and high percentage of relapses. Therefore, there is a great need to develop new strategies of antifungal therapies. We previously found that oxythiamine decreases proliferation of yeast (Saccharomyces cerevisiae), therefore we suggest that thiamine antivitamins can be considered as antifungal agents. The aim of this study was the comparison of thiamine antivitamins (oxythiamine, amprolium, thiochrome, tetrahydrothiamine and tetrahydrooxythiamine) inhibitory effect on the growth rate and energetic metabolism efficiency in non-pathogenic S. cerevisiae and two potentially pathogenic species M. pachydermatis and C. albicans. Investigated species were cultured on a Sabouraud medium supplemented with trace elements in the presence (40 mg l(-1)) or absence of each tested antivitamins to estimate their influence on growth rate, enzyme activity and kinetic parameters of pyruvate decarboxylase and malate dehydrogenase of each tested species. Oxythiamine was the only antivitamin with antifungal potential. M. pachydermatis and S. cerevisiae were the most sensitive, whereas C. albicans was the least sensitive to oxythiamine action. Oxythiamine can be considered as supportive agent in superficial mycoses treatment, especially those caused by species from the genus Malassezia.

  5. Dithiocarbamates are strong inhibitors of the beta-class fungal carbonic anhydrases from Cryptococcus neoformans, Candida albicans and Candida glabrata.

    PubMed

    Monti, Simona Maria; Maresca, Alfonso; Viparelli, Francesca; Carta, Fabrizio; De Simone, Giuseppina; Mühlschlegel, Fritz A; Scozzafava, Andrea; Supuran, Claudiu T

    2012-01-15

    A series of N-mono- and N,N-disubstituted dithiocarbamates have been investigated as inhibitors of three β-carbonic anhydrases (CAs, EC 4.2.1.1) from the fungal pathogens Cryptococcus neoformans, Candida albicans and Candida glabrata, that is, Can2, CaNce103 and CgNce103, respectively. These enzymes were inhibited with efficacies between the subnanomolar to the micromolar range, depending on the substitution pattern at the nitrogen atom from the dithiocarbamate zinc-binding group. This new class of β-CA inhibitors may have the potential for developing antifungal agents with a diverse mechanism of action compared to the clinically used drugs for which drug resistance was reported, and may also explain the efficacy of dithiocarbamates as agricultural antifungal agents. PMID:22209456

  6. Isolation and chemical characterization of plasma membranes from the yeast and mycelial forms of Candida albicans.

    PubMed

    Marriott, M S

    1975-01-01

    It has been possible to induce the yeast-mycelium transformation in Candida albicans by growth of the organism under completely defined conditions in batch culture. Protoplasts have been obtained from the two forms by using a lytic enzyme preparation from Streptomyces violaceus. A plasma membrane fraction was prepared by osmotic lysis of these protoplasts and fractionated by using a combination of differential and discontinuous sucrose density-gradient flotation centrifugation. The purity of this fraction was determined by radioactive dansylation and iodination of plasma membranes of intact protoplasts followed by localization of the radioactivity upon fractionation. This procedure demonstrated less than 4% contamination of the plasma membrane fraction with other cell membranes. Chemical analysis of this fraction revealed that the major components were protein and lipid. Membranes from the yeast form contained (w/w): 50% protein, 45% lipid, 9% carbohydrate and 0.3% nucleic acid. Plasma membranes from the mycelial form contained significantly more carbohydrate and were found to be composed of (w/w): 43% protein, 31% lipid, 25% carbohydrate and 0.5% nucleic acid. Marked differences were also observed between the phospholipid, free and esterified sterols, and total fatty acids of membranes from the two forms of the organism. PMID:1089750

  7. Signalling mucin Msb2 Regulates adaptation to thermal stress in Candida albicans

    PubMed Central

    Saraswat, Darpan; Kumar, Rohitashw; Pande, Tanaya; Edgerton, Mira; Cullen, Paul J.

    2016-01-01

    Summary Temperature is a potent inducer of fungal dimorphism. Multiple signalling pathways control the response to growth at high temperature, but the sensors that regulate these pathways are poorly defined. We show here that the signalling mucin Msb2 is a global regulator of temperature stress in the fungal pathogen Candida albicans. Msb2 was required for survival and hyphae formation at 42°C. The cytoplasmic signalling domain of Msb2 regulated temperature-dependent activation of the CEK mitogen activated proteins kinase (MAPK) pathway. The extracellular glycosylated domain of Msb2 (100–900 amino acid residues) had a new and unexpected role in regulating the protein kinase C (PKC) pathway. Msb2 also regulated temperature-dependent induction of genes encoding regulators and targets of the unfolded protein response (UPR), which is a protein quality control (QC) pathway in the endoplasmic reticulum that controls protein folding/degradation in response to high temperature and other stresses. The heat shock protein and cell wall component Ssa1 was also required for hyphae formation and survival at 42° C and regulated the CEK and PKC pathways. PMID:26749104

  8. Evaluation of antifungal activity of white-colored mineral trioxide aggregate on different strains of Candida albicans in vitro

    PubMed Central

    Bhardwaj, Archana; Bhardwaj, Abhishek; Rao, Nageshwar

    2014-01-01

    Aim: The purpose of this study was to evaluate the antifungal action of various concentrations of white mineral trioxide aggregate (MTA) against seven different strains of Candida albicans using the tube dilution test. Materials and Methods: Fresh mix of MTA was prepared at concentrations of 100, 50, 25, and 12.5 mg/ml and added to a broth tube containing Sabouraud's liquid medium. A total of 1287 broth tubes were prepared and divided into experimental and control groups. Stock cultures of seven strains of C. albicans were obtained. Fresh inoculate of the microorganism was prepared by growing overnight cultures. Aliquots of the test C. albicans were taken and added to the test tubes. All tubes were incubated at 37°C for 1-, 24-, 72-, and 168-h time periods. At each time period, the presence of C. albicans colonies was assessed. Statistical analysis used: Differences among the groups were statistically analyzed using Kruskal–Wallis and Mann–Whitney U tests. Results: Results showed that one strain showed resistance even after 3 days at the lower MTA concentrations of 12.5 and 25 mg/ml. Growth reoccurred with three strains at MTA concentration of 12.5 mg/ml after 7 days. A significant difference was found between strain 3 and other strains at MTA concentrations of 12.5 and 25 mg/ml at the 3-days time period and between tubes containing 12.5 mg/ml and tubes containing higher concentrations of MTA at the 7-days time period. Conclusion: White MTA in concentrations of 100 and 50 mg/ml is effective in inhibiting the seven tested strains of C. albicans for periods up to 1 week. PMID:24944454

  9. Impaired killing of Candida albicans by granulocytes mobilized for transfusion purposes: a role for granule components

    PubMed Central

    Gazendam, Roel P.; van de Geer, Annemarie; van Hamme, John L.; Tool, Anton T.J.; van Rees, Dieke J.; Aarts, Cathelijn E.M.; van den Biggelaar, Maartje; van Alphen, Floris; Verkuijlen, Paul; Meijer, Alexander B.; Janssen, Hans; Roos, Dirk; van den Berg, Timo K.; Kuijpers, Taco W.

    2016-01-01

    Granulocyte transfusions are used to treat neutropenic patients with life-threatening bacterial or fungal infections that do not respond to anti-microbial drugs. Donor neutrophils that have been mobilized with granulocyte-colony stimulating factor (G-CSF) and dexamethasone are functional in terms of antibacterial activity, but less is known about their fungal killing capacity. We investigated the neutrophil-mediated cytotoxic response against C. albicans and A. fumigatus in detail. Whereas G-CSF/dexamethasone-mobilized neutrophils appeared less mature as compared to neutrophils from untreated controls, these cells exhibited normal ROS production by the NADPH oxidase system and an unaltered granule mobilization capacity upon stimulation. G-CSF/dexamethasone-mobilized neutrophils efficiently inhibited A. fumigatus germination and killed Aspergillus and Candida hyphae, but the killing of C. albicans yeasts was distinctly impaired. Following normal Candida phagocytosis, analysis by mass spectrometry of purified phagosomes after fusion with granules demonstrated that major constituents of the antimicrobial granule components, including major basic protein (MBP), were reduced. Purified MBP showed candidacidal activity, and neutrophil-like Crisp-Cas9 NB4-KO-MBP differentiated into phagocytes were impaired in Candida killing. Together, these findings indicate that G-CSF/dexamethasone-mobilized neutrophils for transfusion purposes have a selectively impaired capacity to kill Candida yeasts, as a consequence of an altered neutrophil granular content. PMID:26802050

  10. Impaired killing of Candida albicans by granulocytes mobilized for transfusion purposes: a role for granule components.

    PubMed

    Gazendam, Roel P; van de Geer, Annemarie; van Hamme, John L; Tool, Anton T J; van Rees, Dieke J; Aarts, Cathelijn E M; van den Biggelaar, Maartje; van Alphen, Floris; Verkuijlen, Paul; Meijer, Alexander B; Janssen, Hans; Roos, Dirk; van den Berg, Timo K; Kuijpers, Taco W

    2016-05-01

    Granulocyte transfusions are used to treat neutropenic patients with life-threatening bacterial or fungal infections that do not respond to anti-microbial drugs. Donor neutrophils that have been mobilized with granulocyte-colony stimulating factor (G-CSF) and dexamethasone are functional in terms of antibacterial activity, but less is known about their fungal killing capacity. We investigated the neutrophil-mediated cytotoxic response against C. albicans and A. fumigatus in detail. Whereas G-CSF/dexamethasone-mobilized neutrophils appeared less mature as compared to neutrophils from untreated controls, these cells exhibited normal ROS production by the NADPH oxidase system and an unaltered granule mobilization capacity upon stimulation. G-CSF/dexamethasone-mobilized neutrophils efficiently inhibited A. fumigatus germination and killed Aspergillus and Candida hyphae, but the killing of C. albicans yeasts was distinctly impaired. Following normal Candida phagocytosis, analysis by mass spectrometry of purified phagosomes after fusion with granules demonstrated that major constituents of the antimicrobial granule components, including major basic protein (MBP), were reduced. Purified MBP showed candidacidal activity, and neutrophil-like Crisp-Cas9 NB4-KO-MBP differentiated into phagocytes were impaired in Candida killing. Together, these findings indicate that G-CSF/dexamethasone-mobilized neutrophils for transfusion purposes have a selectively impaired capacity to kill Candida yeasts, as a consequence of an altered neutrophil granular content. PMID:26802050

  11. Thymol has antifungal activity against Candida albicans during infection and maintains the innate immune response required for function of the p38 MAPK signaling pathway in Caenorhabditis elegans.

    PubMed

    Shu, Chengjie; Sun, Lingmei; Zhang, Weiming

    2016-08-01

    The Caenorhabditis elegans model can be used to study Candida albicans virulence and host immunity, as well as to identify plant-derived natural products to use against C. albicans. Thymol is a hydrophobic phenol compound from the aromatic plant thyme. In this study, the in vitro data demonstrated concentration-dependent thymol inhibition of both C. albicans growth and biofilm formation during different developmental phases. With the aid of the C. elegans system, we performed in vivo assays, and our results further showed the ability of thymol to increase C. elegans life span during infection, inhibit C. albicans colony formation in the C. elegans intestine, and increase the expression levels of host antimicrobial genes. Moreover, among the genes that encode the p38 MAPK signaling pathway, mutation of the pmk-1 or sek-1 gene decreased the beneficial effects of thymol's antifungal activity against C. albicans and thymol's maintenance of the innate immune response in nematodes. Western blot data showed the level of phosphorylation of pmk-1 was dramatically decreased against C. albicans. In nematodes, treatment with thymol recovered the dysregulation of pmk-1 and sek-1 gene expressions, the phosphorylation level of PMK-1 caused by C. albicans infection. Therefore, thymol may act, at least in part, through the function of the p38 MAPK signaling pathway to protect against C. albicans infection and maintain the host innate immune response to C. albicans. Our results indicate that the p38 MAPK signaling pathway plays a crucial role in regulating the beneficial effects observed after nematodes infected with C. albicans were treated with thymol. PMID:26783030

  12. Development of oxidative stress tolerance resulted in reduced ability to undergo morphologic transitions and decreased pathogenicity in a t-butylhydroperoxide-tolerant mutant of Candida albicans.

    PubMed

    Fekete, Andrea; Emri, Tamás; Gyetvai, Agnes; Gazdag, Zoltán; Pesti, Miklós; Varga, Zsuzsa; Balla, József; Cserháti, Csaba; Emody, Levente; Gergely, Lajos; Pócsi, István

    2007-09-01

    We tested the hypothesis that adaptation of Candida albicans to chronic oxidative stress inhibits the formation of hyphae and reduces pathogenicity. Candida albicans cells were exposed to increasing concentrations of t-butylhydroperoxide (tBOOH), a lipid peroxidation-accelerating agent, and mutants with heritable tBOOH tolerance were isolated. Hypha formation by the mutants was negligible on Spider agar, indicating that the development of oxidative stress tolerance prevented Candida cells from undergoing dimorphic switches. One of the mutants, C. albicans AF06, was five times less pathogenic in mice than its parental strain, due to its reduced germ tube-, pseudohypha- and hypha-forming capability, and decreased phospholipase secretion. An increased oxidative stress tolerance may therefore be disadvantageous when this pathogen leaves blood vessels and invades deep organs. The AF06 mutant was characterized by high intracellular concentrations of endogenous oxidants, reduced monounsaturated and polyunsaturated fatty acid contents, the continuous induction of the antioxidative defense system, decreased cytochrome c-dependent respiration, and increased alternative respiration. The mutation did not influence growth rate, cell size, cell surface, cellular ultrastructures, including mitochondria, or recognition by human polymorphonuclear leukocytes. The selection of oxidative stress-tolerant respiratory Candida mutants may also occur in vivo, when reduced respiration helps the fungus to cope with antimycotic agents.

  13. Identification of signature volatiles to discriminate Candida albicans, glabrata, krusei and tropicalis using gas chromatography and mass spectrometry.

    PubMed

    Hertel, Moritz; Hartwig, Stefan; Schütte, Eyke; Gillissen, Bernhard; Preissner, Robert; Schmidt-Westhausen, Andrea Maria; Paris, Sebastian; Kastner, Isabell; Preissner, Saskia

    2016-02-01

    Oral candidiasis is the most frequent fungal infection of the oral cavity. Clinical diagnoses require mycological confirmation, which is time-consuming in case of culture testing. The aim of the study was to identify signature volatiles to develop a chairside breath test to diagnose oral candidiasis. Headspaces above Candida albicans, glabrata, tropicalis, krusei cultures, and growth media as control were analysed after eight and 24 h using offline gas chromatography and mass spectrometry. The identification of signature volatiles was assisted using various microbial databases. Retrieved volatile patterns enabled Candida species discrimination in vitro. For C. albicans 3-methyl-2-butanone and styrene and for C. krusei a combination of p-xylene, 2-octanone, 2-heptanone and n-butyl acetate were found to be specific. 1-hexanol was found in C. tropicalis, but is emitted by a variety of other microorganisms. C. glabrata was characterised through the absence of these volatiles. The development of a breath test is a promising approach in confirming suspicions of oral candidiasis. To confirm the retrieved results in vivo, breath tests in affected and healthy subjects have to be performed.

  14. Identification of signature volatiles to discriminate Candida albicans, glabrata, krusei and tropicalis using gas chromatography and mass spectrometry.

    PubMed

    Hertel, Moritz; Hartwig, Stefan; Schütte, Eyke; Gillissen, Bernhard; Preissner, Robert; Schmidt-Westhausen, Andrea Maria; Paris, Sebastian; Kastner, Isabell; Preissner, Saskia

    2016-02-01

    Oral candidiasis is the most frequent fungal infection of the oral cavity. Clinical diagnoses require mycological confirmation, which is time-consuming in case of culture testing. The aim of the study was to identify signature volatiles to develop a chairside breath test to diagnose oral candidiasis. Headspaces above Candida albicans, glabrata, tropicalis, krusei cultures, and growth media as control were analysed after eight and 24 h using offline gas chromatography and mass spectrometry. The identification of signature volatiles was assisted using various microbial databases. Retrieved volatile patterns enabled Candida species discrimination in vitro. For C. albicans 3-methyl-2-butanone and styrene and for C. krusei a combination of p-xylene, 2-octanone, 2-heptanone and n-butyl acetate were found to be specific. 1-hexanol was found in C. tropicalis, but is emitted by a variety of other microorganisms. C. glabrata was characterised through the absence of these volatiles. The development of a breath test is a promising approach in confirming suspicions of oral candidiasis. To confirm the retrieved results in vivo, breath tests in affected and healthy subjects have to be performed. PMID:26667499

  15. In vivo immune responses to Candida albicans modified by treatment with recombinant murine gamma interferon.

    PubMed

    Garner, R E; Kuruganti, U; Czarniecki, C W; Chiu, H H; Domer, J E

    1989-06-01

    The immunologic effects of in vivo administration of recombinant murine gamma interferon (rMuIFN-gamma) were determined in a murine model of candidiasis. Naive mice were given graded doses of rMuIFN-gamma and then challenged intravenously with Candida albicans. Increased morbidity and mortality were noted in four different strains of mice, viz., BALB/c, A/J, Swiss Webster, and CBA/J, providing the mice had not been immunized with C. albicans before challenge. Quantitative culture of selected organs of Swiss Webster and CBA/J mice surviving treatment with rMuIFN-gamma revealed elevated numbers of C. albicans cells, particularly in the kidneys, but also in the liver, lungs, and spleen. The lungs, livers, and spleen of female CBA/J mice were more protected from increased multiplication of the fungus than were those of males of the same species or female Swiss Webster mice. On the basis of these initial findings, the effect of treatment with 5,000 U of rMuIFN-gamma on immune responses in a gastrointestinal model of candidiasis was determined. CBA/J mice that had been colonized with C. albicans as infants were boosted with a cutaneous inoculation of the fungus when 6 to 10 weeks old; development of delayed hypersensitivity (DH), antibodies, and protective responses was assayed at intervals thereafter. Daily treatment with rMuIFN-gamma (beginning 1 day before cutaneous inoculation) suppressed weak immune responses but had little effect on responses which were strong. For example, DH and anti-C. albicans antibody production were suppressed in animals colonized with C. albicans but not boosted by cutaneous inoculation, and DH was suppressed in uncolonized animals that had been inoculated once cutaneously with the fungus as well. There was no rMuIFN-gamma-induced suppressive effect of DH in mice which had been stimulated maximally with C. albicans, i.e., colonized animals that had been boosted cutaneously with the organisms. Collectively, these data indicate that naive mice

  16. In vivo immune responses to Candida albicans modified by treatment with recombinant murine gamma interferon.<