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Sample records for albicans gene png2

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

    Science.gov (United States)

    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.

  2. Comparative transcript profiling of Candida albicans and Candida dubliniensis identifies SFL2, a C. albicans gene required for virulence in a reconstituted epithelial infection model.

    LENUS (Irish Health Repository)

    Spiering, Martin J

    2010-02-01

    Candida albicans and Candida dubliniensis are closely related species displaying differences in virulence and genome content, therefore providing potential opportunities to identify novel C. albicans virulence genes. C. albicans gene arrays were used for comparative analysis of global gene expression in the two species in reconstituted human oral epithelium (RHE). C. albicans (SC5314) showed upregulation of hypha-specific and virulence genes within 30 min postinoculation, coinciding with rapid induction of filamentation and increased RHE damage. C. dubliniensis (CD36) showed no detectable upregulation of hypha-specific genes, grew as yeast, and caused limited RHE damage. Several genes absent or highly divergent in C. dubliniensis were upregulated in C. albicans. One such gene, SFL2 (orf19.3969), encoding a putative heat shock factor, was deleted in C. albicans. DeltaDeltasfl2 cells failed to filament under a range of hypha-inducing conditions and exhibited greatly reduced RHE damage, reversed by reintroduction of SFL2 into the DeltaDeltasfl2 strain. Moreover, SFL2 overexpression in C. albicans triggered hyphal morphogenesis. Although SFL2 deletion had no apparent effect on host survival in the murine model of systemic infection, DeltaDeltasfl2 strain-infected kidney tissues contained only yeast cells. These results suggest a role for SFL2 in morphogenesis and an indirect role in C. albicans pathogenesis in epithelial tissues.

  3. A Candida albicans CRISPR system permits genetic engineering of essential genes and gene families.

    Science.gov (United States)

    Vyas, Valmik K; Barrasa, M Inmaculada; Fink, Gerald R

    Candida albicans is a pathogenic yeast that causes mucosal and systematic infections with high mortality. The absence of facile molecular genetics has been a major impediment to analysis of pathogenesis. The lack of meiosis coupled with the absence of plasmids makes genetic engineering cumbersome, especially for essential functions and gene families. We describe a C. albicans CRISPR system that overcomes many of the obstacles to genetic engineering in this organism. The high frequency with which CRISPR-induced mutations can be directed to target genes enables easy isolation of homozygous gene knockouts, even without selection. Moreover, the system permits the creation of strains with mutations in multiple genes, gene families, and genes that encode essential functions. This CRISPR system is also effective in a fresh clinical isolate of undetermined ploidy. Our method transforms the ability to manipulate the genome of Candida and provides a new window into the biology of this pathogen.

  4. Cloning and Sequencing of a Candida albicans Catalase Gene and Effects of Disruption of This Gene†

    OpenAIRE

    Wysong, Deborah R.; Christin, Laurent; Sugar, Alan M.; Robbins, Phillips W.; Diamond, Richard D.

    1998-01-01

    Catalase plays a key role as an antioxidant, protecting aerobic organisms from the toxic effects of hydrogen peroxide, and in some cases has been postulated to be a virulence factor. To help elucidate the function of catalase in Candida albicans, a single C. albicans-derived catalase gene, designated CAT1, was isolated and cloned. Degenerate PCR primers based on highly conserved areas of other fungal catalase genes were used to amplify a 411-bp product from genomic DNA of C. albicans ATCC 102...

  5. Identification of Drosophila gene products required for phagocytosis of Candida albicans.

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    Shannon L Stroschein-Stevenson

    2006-01-01

    Full Text Available Phagocytosis is a highly conserved aspect of innate immunity. We used Drosophila melanogaster S2 cells as a model system to study the phagocytosis of Candida albicans, the major fungal pathogen of humans, by screening an RNAi library representing 7,216 fly genes conserved among metazoans. After rescreening the initial genes identified and eliminating certain classes of housekeeping genes, we identified 184 genes required for efficient phagocytosis of C. albicans. Diverse biological processes are represented, with actin cytoskeleton regulation, vesicle transport, signaling, and transcriptional regulation being prominent. Secondary screens using Escherichia coli and latex beads revealed several genes specific for C. albicans phagocytosis. Characterization of one of those gene products, Macroglobulin complement related (Mcr, shows that it is secreted, that it binds specifically to the surface of C. albicans, and that it promotes its subsequent phagocytosis. Mcr is closely related to the four Drosophila thioester proteins (Teps, and we show that TepII is required for efficient phagocytosis of E. coli (but not C. albicans or Staphylococcus aureus and that TepIII is required for the efficient phagocytosis of S. aureus (but not C. albicans or E. coli. Thus, this family of fly proteins distinguishes different pathogens for subsequent phagocytosis.

  6. Inhibition of Candida albicans biofilm formation and modulation of gene expression by probiotic cells and supernatant.

    Science.gov (United States)

    James, K M; MacDonald, K W; Chanyi, R M; Cadieux, P A; Burton, J P

    2016-04-01

    Oral candidiasis is a disease caused by opportunistic species of Candida that normally reside on human mucosal surfaces. The transition of Candida from budding yeast to filamentous hyphae allows for covalent attachment to oral epithelial cells, followed by biofilm formation, invasion and tissue damage. In this study, combinations of Lactobacillus plantarum SD5870, Lactobacillus helveticus CBS N116411 and Streptococcus salivarius DSM 14685 were assessed for their ability to inhibit the formation of and disrupt Candida albicans biofilms. Co-incubation with probiotic supernatants under hyphae-inducing conditions reduced C. albicans biofilm formation by >75 % in all treatment groups. Likewise, combinations of live probiotics reduced biofilm formation of C. albicans by >67 %. When live probiotics or their supernatants were overlaid on preformed C. albicans biofilms, biofilm size was reduced by >63 and >65 % respectively. Quantitative real-time PCR results indicated that the combined supernatants of SD5870 and CBS N116411 significantly reduced the expression of several C. albicans genes involved in the yeast-hyphae transition: ALS3 (adhesin/invasin) by 70 % (P biofilm formation) by >99 % (P formation of and removing preformed C. albicans biofilms. Our novel results point to the downregulation of several Candida genes critical to the yeast-hyphae transition, biofilm formation, tissue invasion and cellular damage.

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

    Science.gov (United States)

    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.

  8. Candida albicans Gene Deletion with a Transient CRISPR-Cas9 System.

    Science.gov (United States)

    Min, Kyunghun; Ichikawa, Yuichi; Woolford, Carol A; Mitchell, Aaron P

    2016-01-01

    Clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated gene 9 (CRISPR-Cas9) systems are used for a wide array of genome-editing applications in organisms ranging from fungi to plants and animals. Recently, a CRISPR-Cas9 system has been developed for the diploid fungal pathogen Candida albicans; the system accelerates genetic manipulation dramatically [V. K. Vyas, M. I. Barrasa, and G. R. Fink, Sci Adv 1(3):e1500248, 2015, http://dx.doi.org/10.1126/sciadv.1500248]. We show here that the CRISPR-Cas9 genetic elements can function transiently, without stable integration into the genome, to enable the introduction of a gene deletion construct. We describe a transient CRISPR-Cas9 system for efficient gene deletion in C. albicans. Our observations suggest that there are two mechanisms that lead to homozygous deletions: (i) independent recombination of transforming DNA into each allele and (ii) recombination of transforming DNA into one allele, followed by gene conversion of the second allele. Our approach will streamline gene function analysis in C. albicans, and our results indicate that DNA can function transiently after transformation of this organism. IMPORTANCE The fungus Candida albicans is a major pathogen. Genetic analysis of this organism has revealed determinants of pathogenicity, drug resistance, and other unique biological features, as well as the identities of prospective drug targets. The creation of targeted mutations has been greatly accelerated recently through the implementation of CRISPR genome-editing technology by Vyas et al. [Sci Adv 1(3):e1500248, 2015, http://dx.doi.org/10.1126/sciadv.1500248]. In this study, we find that CRISPR elements can be expressed from genes that are present only transiently, and we develop a transient CRISPR system that further accelerates C. albicans genetic manipulation.

  9. Nuclear fusion occurs during mating in Candida albicans and is dependent on the KAR3 gene.

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    Bennett, Richard J; Miller, Mathew G; Chua, Penelope R; Maxon, Mary E; Johnson, Alexander D

    2005-02-01

    It is now well established that mating can occur between diploid a and alpha cells of Candida albicans. There is, however, controversy over when, and with what efficiency, nuclear fusion follows cell fusion to create stable tetraploid a/alpha cells. In this study, we have analysed the mating process between C. albicans strains using both cytological and genetic approaches. Using strains derived from SC5314, we used a number of techniques, including time-lapse microscopy, to demonstrate that efficient nuclear fusion occurs in the zygote before formation of the first daughter cell. Consistent with these observations, zygotes micromanipulated from mating mixes gave rise to mononuclear tetraploid cells, even when no selection for successful mating was applied to them. Mating between different clinical isolates of C. albicans revealed that while all isolates could undergo nuclear fusion, the efficiency of nuclear fusion varied in different crosses. We also show that nuclear fusion in C. albicans requires the Kar3 microtubule motor protein. Deletion of the CaKAR3 gene from both mating partners had little or no effect on zygote formation but reduced the formation of stable tetraploids more than 600-fold, as determined by quantitative mating assays. These findings demonstrate that nuclear fusion is an active process that can occur in C. albicans at high frequency to produce stable, mononucleate mating products.

  10. Relationship between antifungal resistance of fluconazole resistant Candida albicans and mutations in ERG11 gene

    Institute of Scientific and Technical Information of China (English)

    FENG Li-juan; WAN Zhe; WANG Xiao-hong; LI Ruo-yu; LIU Wei

    2010-01-01

    Background The cytochrome P450 lanosterol 14α-demethylase(Erg11p) encoded by ERG11 gene is the primary target for azole antifungals.Changes in azole affinity of this enzyme caused by amino acid substitutions have been reported as a mechanism of azole antifungal resistance. This study aimed to investigate the relationship between amino acid substitutions in Erg11p from fluconazole resistant Candida albicans (C.albicans)isolates and their cross-resistance to azoles.Methods Mutations in ERG11 gene were screened in 10 clinical isolates of fluconazole resistant C.albicans strains.DNA sequence of ERG11 was determined by PCR based DNA sequencing.Results In the 10 isolates,19 types of amino acid substitutions were found,of which 10 substitutions (F72S, F103L, F145I, F198L, G206D, G227D, N349S, F416S, F422L and T482A) have not been reported previously. Mutations in ERG11 gene were detected in 9 isolates of fluconazole resistant C. albicans, but were not detected in 1 isolate. Conclusions Although no definite correlation was found between the type of amino acid substitutions in Erg11p and the phenotype of cross-resistance to azoles, the substitutions F72S, F145I and G227D in our study may be highly associated with resistance to azoles because of their special location in Erg11p.

  11. Genome-Wide Screen for Haploinsufficient Cell Size Genes in the Opportunistic Yeast Candida albicans

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    Julien Chaillot

    2017-02-01

    Full Text Available One of the most critical but still poorly understood aspects of eukaryotic cell proliferation is the basis for commitment to cell division in late G1 phase, called Start in yeast and the Restriction Point in metazoans. In all species, a critical cell size threshold coordinates cell growth with cell division and thereby establishes a homeostatic cell size. While a comprehensive survey of cell size genetic determinism has been performed in the saprophytic yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, very little is known in pathogenic fungi. As a number of critical Start regulators are haploinsufficient for cell size, we applied a quantitative analysis of the size phenome, using elutriation-barcode sequencing methodology, to 5639 barcoded heterozygous deletion strains of the opportunistic yeast Candida albicans. Our screen identified conserved known regulators and biological processes required to maintain size homeostasis in the opportunistic yeast C. albicans. We also identified novel C. albicans-specific size genes and provided a conceptual framework for future mechanistic studies. Interestingly, some of the size genes identified were required for fungal pathogenicity suggesting that cell size homeostasis may be elemental to C. albicans fitness or virulence inside the host.

  12. Genome-Wide Screen for Haploinsufficient Cell Size Genes in the Opportunistic Yeast Candida albicans

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    Chaillot, Julien; Cook, Michael A.; Corbeil, Jacques; Sellam, Adnane

    2016-01-01

    One of the most critical but still poorly understood aspects of eukaryotic cell proliferation is the basis for commitment to cell division in late G1 phase, called Start in yeast and the Restriction Point in metazoans. In all species, a critical cell size threshold coordinates cell growth with cell division and thereby establishes a homeostatic cell size. While a comprehensive survey of cell size genetic determinism has been performed in the saprophytic yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, very little is known in pathogenic fungi. As a number of critical Start regulators are haploinsufficient for cell size, we applied a quantitative analysis of the size phenome, using elutriation-barcode sequencing methodology, to 5639 barcoded heterozygous deletion strains of the opportunistic yeast Candida albicans. Our screen identified conserved known regulators and biological processes required to maintain size homeostasis in the opportunistic yeast C. albicans. We also identified novel C. albicans-specific size genes and provided a conceptual framework for future mechanistic studies. Interestingly, some of the size genes identified were required for fungal pathogenicity suggesting that cell size homeostasis may be elemental to C. albicans fitness or virulence inside the host. PMID:28040776

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

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    Jiyoti Verma-Gaur

    2015-10-01

    Full Text Available 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.

  14. Nocvel potential targets and related genes of transcription factor Caplp in Candida albicans 1

    Institute of Scientific and Technical Information of China (English)

    YahWANG; Yong-bingCAO; Xin-mingJIA; De-junWANG; ZhengXU; HuiSHEN; KangYING; Wan-shengCHEN; Yuan-yingJIANG

    2005-01-01

    AIM Capl p, encoded by CAP1 in Candida albicans, is highly homologous to Saccharomyces cerevisiae transcription factor Yapl p. It has been associated with tolerance to oxidative stress and resistance to a variety of toxicants previously. We used homemade microarray to reveal Capl p related genes in a broad spectrum as well as to lucubrate the functions of Capl p. METHODS Microarray analysis was used to identify differentially expressed genes between CAP1 deletion strain CJD21 and its parental strain CAI4. CAP1 over-expression strain was constructed to confirm the relationship between CAP1 and some differentially expressedgenes. Bioinformatics was applied to reveal promoters with Capl p binding site as well as the clusters of differentially expressed genes. RT-PCR and drug efflux analysis were used to lucubrate the functions of Caplp in Candida albicans.

  15. Pseudomonas aeruginosa lipopolysaccharide inhibits Candida albicans hyphae formation and alters gene expression during biofilm development.

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    Bandara, H M H N; K Cheung, B P; Watt, R M; Jin, L J; Samaranayake, L P

    2013-02-01

    Elucidation of bacterial and fungal interactions in multispecies biofilms will have major impacts on understanding the pathophysiology of infections. The objectives of this study were to (i) evaluate the effect of Pseudomonas aeruginosa lipopolysaccharide (LPS) on Candida albicans hyphal development and transcriptional regulation, (ii) investigate protein expression during biofilm formation, and (iii) propose likely molecular mechanisms for these interactions. The effect of LPS on C. albicans biofilms was assessed by XTT-reduction and growth curve assays, light microscopy, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM). Changes in candidal hypha-specific genes (HSGs) and transcription factor EFG1 expression were assessed by real-time polymerase chain reaction and two-dimensional gel electrophoresis, respectively. Proteome changes were examined by mass spectrometry. Both metabolic activities and growth rates of LPS-treated C. albicans biofilms were significantly lower (P GDH1), CaO19.11135(PGK1), CaO19.9877(HNT1) by P. aeruginosa LPS. Our data imply that bacterial LPS inhibit C. albicans biofilm formation and hyphal development. The P. aeruginosa LPS likely target glycolysis-associated mechanisms during candidal filamentation.

  16. The Candida albicans-specific gene EED1 encodes a key regulator of hyphal extension.

    LENUS (Irish Health Repository)

    Martin, Ronny

    2011-04-01

    The extension of germ tubes into elongated hyphae by Candida albicans is essential for damage of host cells. The C. albicans-specific gene EED1 plays a crucial role in this extension and maintenance of filamentous growth. eed1Δ cells failed to extend germ tubes into long filaments and switched back to yeast growth after 3 h of incubation during growth on plastic surfaces. Expression of EED1 is regulated by the transcription factor Efg1 and ectopic overexpression of EED1 restored filamentation in efg1Δ. Transcriptional profiling of eed1Δ during infection of oral tissue revealed down-regulation of hyphal associated genes including UME6, encoding another key transcriptional factor. Ectopic overexpression of EED1 or UME6 rescued filamentation and damage potential in eed1Δ. Transcriptional profiling during overexpression of UME6 identified subsets of genes regulated by Eed1 or Ume6. These data suggest that Eed1 and Ume6 act in a pathway regulating maintenance of hyphal growth thereby repressing hyphal-to-yeast transition and permitting dissemination of C. albicans within epithelial tissues.

  17. Transcript profiling reveals rewiring of iron assimilation gene expression in Candida albicans and C. dubliniensis.

    LENUS (Irish Health Repository)

    Moran, Gary P

    2012-12-01

    Hyphal growth is repressed in Candida albicans and Candida dubliniensis by the transcription factor Nrg1. Transcript profiling of a C. dubliniensis NRG1 mutant identified a common group of 28 NRG1-repressed genes in both species, including the hypha-specific genes HWP1, ECE1 and the regulator of cell elongation UME6. Unexpectedly, C. dubliniensis NRG1 was required for wild-type levels of expression of 10 genes required for iron uptake including seven ferric reductases, SIT1, FTR1 and RBT5. However, at alkaline pH and during filamentous growth in 10% serum, most of these genes were highly induced in C. dubliniensis. Conversely, RBT5, PGA10, FRE10 and FRP1 did not exhibit induction during hyphal growth when NRG1 is downregulated, indicating that in C. dubliniensis NRG1 is also required for optimal expression of these genes in alkaline environments. In iron-depleted medium at pH 4.5, reduced growth of the NRG1 mutant relative to wild type was observed; however, growth was restored to wild-type levels or greater at pH 6.5, indicating that alkaline induction of iron assimilation gene expression could rescue this phenotype. These data indicate that transcriptional control of iron assimilation and pseudohypha formation has been separated in C. albicans, perhaps promoting growth in a wider range of niches.

  18. Heterologous expression and biochemical characterization of an α1,2-mannosidase encoded by the Candida albicans MNS1 gene

    OpenAIRE

    2008-01-01

    Protein glycosylation pathways, commonly found in fungal pathogens, offer an attractive new area of study for the discovery of antifungal targets. In particular, these post-translational modifications are required for virulence and proper cell wall assembly in Candida albicans, an opportunistic human pathogen. The C. albicans MNS1 gene is predicted to encode a member of the glycosyl hydrolase family 47, with 1,2-mannosidase activity. In order to characterise its activity, we first cloned the ...

  19. Development and evaluation of different normalization strategies for gene expression studies in Candida albicans biofilms by real-time PCR

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    Deforce Dieter

    2006-08-01

    Full Text Available Abstract Background Candida albicans biofilms are commonly found on indwelling medical devices. However, the molecular basis of biofilm formation and development is not completely understood. Expression analysis of genes potentially involved in these processes, such as the ALS (Agglutinine Like Sequence gene family can be performed using quantitative PCR (qPCR. In the present study, we investigated the expression stability of eight housekeeping genes potentially useful as reference genes to study gene expression in Candida albicans (C. albicans biofilms, using the geNorm Visual Basic Application (VBA for Microsoft Excel. To validate our normalization strategies we determined differences in ALS1 and ALS3 expression levels between C. albicans biofilm cells and their planktonic counterparts. Results The eight genes tested in this study are ranked according to their expression stability (from most stable to least stable as follows: ACT1 (β-actin/PMA1 (adenosine triphosphatase, RIP (ubiquinol cytochrome-c reductase complex component, RPP2B (cytosolic ribosomal acidic protein P2B, LSC2 (succinyl-CoA synthetase β-subunit fragment, IMH3 (inosine-5'-monophosphate dehydrogenase fragment, CPA1 (carbamoyl-phosphate synthethase small subunit and GAPDH (glyceraldehyde-3-phosphate dehydrogenase. Our data indicate that five genes are necessary for accurate and reliable normalization of gene expression data in C. albicans biofilms. Using different normalization strategies, we found a significant upregulation of the ALS1 gene and downregulation of the ALS3 gene in C. albicans biofilms grown on silicone disks in a continous flow system, the CDC reactor (Centre for Disease Control, for 24 hours. Conclusion In conclusion, we recommend the use of the geometric mean of the relative expression values from the five housekeeping genes (ACT1, PMA1, RIP, RPP2B and LSC2 for normalization, when analysing differences in gene expression levels between C. albicans biofilm

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

    Science.gov (United States)

    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.

  1. ALS1 and ALS3 gene expression and biofilm formation in Candida albicans isolated from vulvovaginal candidiasis

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    Shahla Roudbarmohammadi

    2016-01-01

    Conclusion: The results attained indicated that there is an association between the expression of ALS1 and ALS3 genes and fluconazole resistance in C. albicans. A considerable percent of the isolates expressing the ALS1 and ALS3 genes may have contributed to their adherence to vagina and biofilm formation.

  2. Rapid detection of Candida albicans in clinical samples by DNA amplification of common regions from C. albicans-secreted aspartic proteinase genes.

    Science.gov (United States)

    Flahaut, M; Sanglard, D; Monod, M; Bille, J; Rossier, M

    1998-02-01

    Laboratory diagnosis based on genomic amplification methods such as PCR may provide an alternative and more sensitive method than conventional culture for the early detection of deep-seated candidiasis, an increasing cause of morbidity and mortality among immunocompromised patients. A novel method of DNA extraction from clinical samples based on treatment with proteinase K and isolation of DNA on a silica membrane was developed. The targets used for DNA amplification were the Candida albicans-secreted aspartic proteinase (SAP) genes, a multiple-gene family of at least seven members in C. albicans. A single pair of primers was designed in order to detect six of these SAP genes and, subsequently, to increase the sensitivity of the test. Detection of the PCR product by enzyme-linked immunosorbent assay was found to be as sensitive as Southern blotting with an SAP-labeled probe. The sensitivity of the assay was 1 cell/ml from serially diluted Candida cultures and 1 to 4 cells/ml from seeded blood specimens. The sensitivity and specificity of the present assay were tested in a retrospective study performed blindly with 156 clinical samples and were 100 and 98%, respectively, compared with the results of culture. For the subset of blood culture samples (n = 124), the sensitivity and the specificity were 100%. The two false-positive PCR samples came from patients treated with azole antifungal agents, indicating that PCR was probably able to detect damaged organisms that could not be recovered by culture.

  3. Investigation of ERG11 gene expression among fluconazole-resistant Candida albicans: first report from an Iranian referral paediatric hospital.

    Science.gov (United States)

    Teymuri, M; Mamishi, S; Pourakbari, B; Mahmoudi, S; Ashtiani, M T; Sadeghi, R H; Yadegari, M H

    2015-01-01

    The multiplicity of mechanisms of resistance to azole antifungal agents has been described. As fluconazole-resistant clinical Candida albicans isolates that constitutively over-express ERG11 have been identified in previous studies, the aim of this study is to investigate this molecular mechanism involved in fluconazole resistance of C. albicans clinical isolates. Fluconazole susceptibility testing was carried out on clinical isolates of Candida spp. obtained from hospitalised children in an Iranian referral children's hospital. A polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique was used to differentiate Candida spp. The resistant C. albicans isolates were subjected to RT-qPCR using primers that identify ERG11 gene expression. Of the 142 Candida spp. isolates studied, C. albicans was the most predominant isolate, occurring in 68.3% (97/142) of the patients. According to the CLSI method, the majority of the C. albicans isolates (91.7%, 89/97), categorised as susceptible (minimum inhibitory concentration [MIC] ≤8 μg/mL), five isolates were considered resistant (MIC ≤64 μg/mL) and three had dose-dependent susceptibility (MIC = 8.16-32 μg/mL). The ERG11 gene in the five fluconazole-resistant C. albicans isolates was upregulated 4.15-5.84-fold relative to the ATCC 10231 control strain. In this study, the expression of ERG11 was upregulated in all the fluconazole-resistant C. albicans isolates. There are limited data on the antifungal susceptibility of Candida spp. as well as the molecular mechanism of azole resistance in Iran, especially for isolates causing infections in children. Therefore, the surveillance of antifungal resistance patterns and investigation of other mechanisms of azole resistance in all Candida spp. isolates is recommended.

  4. Identification of genes differentially expressed in hyphae of Candida albicans Identificação de gases em hifa de Candida albicans

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    Analy Salles de Azevedo Melo

    2003-11-01

    Full Text Available The ability to switch from yeast to hyphal forms is essential for Candida albicans virulence. This morphological switch involves the expression of hyphal-specific genes under the control of transcriptional factors. To contribute to the discovery of hyphal-specific genes, we used a differential screening method where clones of a genomic DNA library were hybridized with yeast and hyphal cDNA probes. Two clones with increased expression in hyphae were selected for study. Sequencing these clones, we found that they encoded two important metabolic genes, CaHXT7 (high-affinity hexose transporter and CaYLL34 (member of the AAA ATPase family. CaHXT7 and CaYLL34 ORFs were completely determined. Analyses of the putative proteins show that: (1 CaHxt7p has one hexose transporter domain and (2 CaYll34p has two AAA ATPase domains. These results show, for the first time, increased expression of metabolic genes in C. albicans hyphae. Also, because the proteins encoded by CaHXT7 and CaYLL34 may be necessary for the switching to hyphae, they could be new targets for antifungal drugs.A transição morfológica de levedura para hifa é essencial para a virulência de Candida albicans. Esta transição envolve a expressão de genes hifa-específicos que estão sob o controle de fatores transcricionais. Para descobrir genes hifa-específicos utilizamos um método de triagem diferencial, onde clones de biblioteca de DNA genômico foram hibridizados com sondas de cDNA de levedura e hifa. Dois clones com aumento de expressão em hifa foram selecionados. O sequenciamento dos insertos destes clones permitiu a identificação de dois genes metabólicos importantes: CaHXT7 (high-affinity hexose transporter e CaYLL34 (da família AAA ATPase. As ORFs completas destes genes foram caracterizadas e a análise das proteínas hipotéticas revelou que: (1 CaHxt7p tem um domínio de transportador de hexose e (2 CaYll34 tem dois domínios AAA ATPase. Este é o primeiro estudo que

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

    Science.gov (United States)

    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.

  6. A simple approach for estimating gene expression in Candida albicans directly from a systemic infection site.

    Science.gov (United States)

    Andes, D; Lepak, A; Pitula, A; Marchillo, K; Clark, J

    2005-09-01

    Gene expression analysis after the host-pathogen interaction is revolutionizing our understanding of the host response to infection. Numerous studies have utilized microarray analysis to follow host cell transcriptome alterations in response to interactions with infectious pathogens. However, similar analyses of pathogen transcriptional adaptation at the infection site have been limited. Understanding the nature of this interaction from the pathogen perspective at different sites and stages of infection is central to strategies for development of new anti-infective therapies. Toward this end, we developed a protocol to analyze changes in gene expression for a eukaryotic pathogen, Candida albicans, during systemic infection in mice. The experimental approach takes advantage of the resistance of the cell wall of many fungal pathogens to cell lysis, relative to mammalian cells. After lysis of mammalian cells, the tissue mixture containing fungal cells is depleted of mammalian RNA by centrifugation, followed by enzymatic digestion. RNA-digesting enzymes are then inhibited before eukaryotic cell lysis and RNA isolation. The protocol provides a reproducible quantity of RNA based on pathogen cell number. The quality of the RNA allowed reliable downstream transcriptional analysis using reverse-transcription polymerase chain reaction and microarrays. The in vivo gene expression data confirmed involvement of several putative pathogenesis genes. More importantly, the results provided a wealth of biologically interesting hypotheses to direct future investigation.

  7. A Candida albicans gene expressed in Saccharomyces cerevisiae results in a distinct pattern of mRNA processing.

    Science.gov (United States)

    Iborra, A; Sentandreu, R; Gozalbo, D

    1996-09-01

    Two plasmids (derived from YCplac22 and YEplac112) carrying a Candida albicans gene (including the 5' non-coding promoter sequences) coding for a 30 kDa membrane-bound protein, were used to transform Saccharomyces cerevisiae cells. A 30 kDa protein was immunodetected by Western blot in the membrane fraction of transformants. Northern analysis showed the presence of three mRNA species (of about 1.1, 0.7 and 0.5 kb) hybridizing with the C. albicans gene as a probe. The same result was obtained using the 5' and 3' regions of the gene as probes, whereas only a 1.1 kb mRNA was found in C. albicans and none was detected in S. cerevisiae control transformants. Thus, heterologous expression of this gene in S. cerevisiae results in a distinct pattern of mRNA processing, either due to the location on plasmid vectors and/or to differences in the mRNA processing systems in the two microorganisms.

  8. The expression of genes involved in the ergosterol biosynthesis pathway in Candida albicans and Candida dubliniensis biofilms exposed to fluconazole.

    LENUS (Irish Health Repository)

    2009-03-01

    The expression of the ERG1, ERG3, ERG7, ERG9, ERG11 and ERG25 genes in response to incubation with fluconazole and biofilm formation was investigated using reverse-transcription PCR and real-time PCR in Candida albicans and Candida dubliniensis clinical isolates. The viability of biofilm was measured using an 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay and confocal scanning laser microscopy (CSLM). Expression of the ERG11 gene was found to be low or moderate and it was regulated by fluconazole addition more so than by biofilm formation. Very low or non-detectable expression of ERG1, ERG7 and ERG25 genes was detected in C. albicans. The expression of the ERG9 increased in the presence of fluconazole in some isolates. Following incubation with fluconazole, formation of biofilm by C. dubliniensis was coupled with up-regulation of the ERG3 and ERG25 genes as have been observed previously in C. albicans. Planktonic cells of both Candida species released from biofilm displayed similar resistance mechanisms to fluconazole like attached cells. The XTT reduction assay and CSLM revealed that although incubation with fluconazole decreased the biofilm thickness, these were still comprised metabolically active cells able to disseminate and produce biofilm. Our data indicate that biofilm represents a highly adapted community reflecting the individuality of clinical isolates.

  9. Heterologous expression and biochemical characterization of an α1,2-mannosidase encoded by the Candida albicans MNS1 gene

    Directory of Open Access Journals (Sweden)

    Héctor M Mora-Montes

    2008-11-01

    Full Text Available Protein glycosylation pathways, commonly found in fungal pathogens, offer an attractive new area of study for the discovery of antifungal targets. In particular, these post-translational modifications are required for virulence and proper cell wall assembly in Candida albicans, an opportunistic human pathogen. The C. albicans MNS1 gene is predicted to encode a member of the glycosyl hydrolase family 47, with 1,2-mannosidase activity. In order to characterise its activity, we first cloned the C. albicans MNS1 gene into Escherichia coli, then expressed and purified the enzyme. The recombinant Mns1 was capable of converting a Man9GlcNAc2 N-glycan core into Man8GlcNAc2 isomer B, but failed to process a Man5GlcNAc2-Asn N-oligosaccharide. These properties are similar to those displayed by Mns1 purified from C. albicansmembranes and strongly suggest that the enzyme is an ±1,2-mannosidase that is localised to the endoplasmic reticulum and involved in the processing of N-linked mannans. Polyclonal antibodies specifically raised against recombinant Mns1 also immunoreacted with the soluble ±1,2-mannosidases E-I and E-II, indicating that Mns1 could share structural similarities with both soluble enzymes. Due to the high degree of similarity between the members of family 47, it is conceivable that these antibodies may recognise ±1,2-mannosidases in other biological systems as well.

  10. Candida albicans commensalism in the gastrointestinal tract.

    Science.gov (United States)

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

    2015-11-01

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

  11. Evaluation of gene expression SAP5, LIP9, and PLB2 of Candida albicans biofilms after photodynamic inactivation.

    Science.gov (United States)

    Freire, Fernanda; de Barros, Patrícia Pimentel; da Silva Ávila, Damara; Brito, Graziella Nuernberg Back; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso

    2015-07-01

    With the increasing number of strains of Candida ssp. resistant to antifungal agents, the accomplishment of researches that evaluate the effects of new therapeutic methods, like photodynamic inactivation (PDI), becomes important and necessary. Thus, the objective of this study was to verify the effects of the PDI on Candida albicans biofilms, evaluating their effects on the expression of the gene hydrolytic enzymes aspartyl proteinase (SAP5), lipase (LIP9), and phospholipase (PLB2). Clinical strains of C. albicans (n = 9) isolated from patient bearers of the virus HIV and a pattern strain ATCC 18804 were used. The quantification of gene expression was related to the production of hydrolytic enzymes using the quantitative polymerase chain reaction (qPCR) assay. For PDI, we used laser-aluminum-gallium arsenide low power (red visible, 660 nm) as a light source and the methylene blue at 300 μM as a photosensitizer. We assessed two experimental groups for each strain: (a) PDI: sensitization with methylene blue and laser irradiation and (b) control: without sensitization with methylene blue and light absence. The PDI decreased gene expression in 60 % of samples for gene SAP5 and 50 % of the samples decreased expression of LIP9 and PLB2. When we compared the expression profile for of each gene between the treated and control group, a decrease in all gene expression was observed, however no statistically significant difference (Tukey's test/p = 0.12). It could be concluded that PDI (photosensitization with methylene blue followed by low-level laser irradiation) showed a slight reduction on the expression of hydrolytic enzymes of C. albicans, without statistical significance.

  12. α-Pheromone-Induced “Shmooing” and Gene Regulation Require White-Opaque Switching during Candida albicans Mating

    OpenAIRE

    Lockhart, Shawn R.; Zhao, Rui; Daniels, Karla J.; Soll, David R.

    2003-01-01

    A 14-mer α-pheromone peptide of Candida albicans was chemically synthesized and used to analyze the role of white-opaque switching in the mating process. The α-pheromone peptide blocked cell multiplication and induced “shmooing” in a/a cells expressing the opaque-phase phenotype but not in a/a cells expressing the white-phase phenotype. The α-pheromone peptide induced these effects at 25°C but not at 37°C. An analysis of mating-associated gene expression revealed several categories of gene re...

  13. Effect of long-term exposure to mobile phone radiation on alpha-Int1 gene sequence of Candida albicans.

    Science.gov (United States)

    Shahin-Jafari, Ariyo; Bayat, Mansour; Shahhosseiny, Mohammad Hassan; Tajik, Parviz; Roudbar-Mohammadi, Shahla

    2016-05-01

    Over the last decade, communication industries have witnessed a tremendous expansion, while, the biological effects of electromagnetic waves have not been fully elucidated. Current study aimed at evaluating the mutagenic effect of long-term exposure to 900-MHz radiation on alpha-Int1 gene sequences of Candida albicans. A standard 900 MHz radiation generator was used for radiation. 10 ml volumes from a stock suspension of C. albicans were transferred into 10 polystyrene tubes. Five tubes were exposed at 4 °C to a fixed magnitude of radiation with different time periods of 10, 70, 210, 350 and 490 h. The other 5 tubes were kept far enough from radiation. The samples underwent genomic DNA extraction. PCR amplification of alpha-Int1 gene sequence was done using one set of primers. PCR products were resolved using agarose gel electrophoresis and the nucleotide sequences were determined. All samples showed a clear electrophoretic band around 441 bp and further sequencing revealed the amplified DNA segments are related to alpha-Int1 gene of the yeast. No mutations in the gene were seen in radiation exposed samples. Long-term exposure of the yeast to mobile phone radiation under the above mentioned conditions had no mutagenic effect on alpha-Int1 gene sequence.

  14. Real-time PCR expression profiling of genes encoding potential virulence factors in Candida albicans biofilms: identification of model-dependent and -independent gene expression

    Directory of Open Access Journals (Sweden)

    Řičicová Markéta

    2010-04-01

    Full Text Available Abstract Background Candida albicans infections are often associated with biofilm formation. Previous work demonstrated that the expression of HWP1 (hyphal wall protein and of genes belonging to the ALS (agglutinin-like sequence, SAP (secreted aspartyl protease, PLB (phospholipase B and LIP (lipase gene families is associated with biofilm growth on mucosal surfaces. We investigated using real-time PCR whether genes encoding potential virulence factors are also highly expressed in biofilms associated with abiotic surfaces. For this, C. albicans biofilms were grown on silicone in microtiter plates (MTP or in the Centres for Disease Control (CDC reactor, on polyurethane in an in vivo subcutaneous catheter rat (SCR model, and on mucosal surfaces in the reconstituted human epithelium (RHE model. Results HWP1 and genes belonging to the ALS, SAP, PLB and LIP gene families were constitutively expressed in C. albicans biofilms. ALS1-5 were upregulated in all model systems, while ALS9 was mostly downregulated. ALS6 and HWP1 were overexpressed in all models except in the RHE and MTP, respectively. The expression levels of SAP1 were more pronounced in both in vitro models, while those of SAP2, SAP4 and SAP6 were higher in the in vivo model. Furthermore, SAP5 was highly upregulated in the in vivo and RHE models. For SAP9 and SAP10 similar gene expression levels were observed in all model systems. PLB genes were not considerably upregulated in biofilms, while LIP1-3, LIP5-7 and LIP9-10 were highly overexpressed in both in vitro models. Furthermore, an elevated lipase activity was detected in supernatans of biofilms grown in the MTP and RHE model. Conclusions Our findings show that HWP1 and most of the genes belonging to the ALS, SAP and LIP gene families are upregulated in C. albicans biofilms. Comparison of the fold expression between the various model systems revealed similar expression levels for some genes, while for others model-dependent expression

  15. White-opaque Switching in Different Mating Type-like Locus Gene Types of Clinical Candida albicans Isolates

    Science.gov (United States)

    Li, Hou-Min; Shimizu-Imanishi, Yumi; Tanaka, Reiko; Li, Ruo-Yu; Yaguchi, Takashi

    2016-01-01

    Background: Candida albicans (C. albicans) can become a pathogen causing superficial as well as life-threatening systemic infections, especially in immunocompromised patients. Many phenotypic attributes contribute to its capacity to colonize human organs. In our study, 93 C. albicans isolates from patients of various candidiasis in a hospital of China were surveyed. We aimed to investigate the white-opaque (WO) switching competence, drug sensitivity, and virulence of mating type-like (MTL) a/α isolates. Methods: Internal transcribed spacer (ITS) gene and the MTL configuration were detected in all the isolates by reverse transcription-polymerase chain reaction. White/opaque phenotype and doubling time of cell growth were determined. The minimum inhibitory concentrations of antifungal agent were measured using broth microdilution method. Results: Sixty-four isolates (69.6%) were classified to serotype A, 19 (20.6%) to serotype B, and 9 (9.8%) to serotype C. Moreover, phylogenetic analysis showed that these isolates were divided into four different subgroups of ITS genotypes. Most of our clinical isolates were MTLa/α type, while 6.8% remained MTLa or MTLα type. The frequency of opaque phenotype was 71.0% (66 isolates). Following the guidelines of Clinical and Laboratory Standards Institute M27-A3, all isolates were susceptible to caspofungin and a few (0.6–3.2%) of them showed resistance against amphotericin B, flucytosine, fluconazole, itraconazole, and voriconazole. Conclusions: From these analyses, there were comparatively more C. albicans strains classified into serotype B, and the frequency of opaque phase strains was significant in the clinical isolates from China. Genetic, phenotypic, or drug susceptibility patterns were not significantly different from previous studies. MTLa/α isolates could also undergo WO switching which facilitates their survival. PMID:27824006

  16. cDNA Array Analysis of the Differential Expression Change in Virulence-related Genes During the Development of Resistance in Candida albicans

    Institute of Scientific and Technical Information of China (English)

    Zheng XU; Yuan-Ying JIANG; Yong-Bing CAO; Jun-Dong ZHANG; Ying-Ying CAO; Ping-Hui GAO; De-Jun WANG; Xu-Ping FU; Kang YING; Wan-Sheng CHEN

    2005-01-01

    Candida albicans is the most frequently isolated fungus in immunocompromised patients associated with mucosal and deep-tissue infections. To investigate the correlation between virulence and resistance on a gene expression profile in C. albicans, we examined the changes in virulence-related genes during the development of resistance in C. albicans from bone marrow transplant patients using a constructed cDNA array representing 3096 unigenes. In addition to the genes known to be associated with azole resistance,16 virulence-related genes were identified, whose differential expressions were newly found to be associated with the resistant phenotype. Differential expressions for these genes were confirmed by RT-PCR independently. Furthermore, the up-regulation of EFG1, CPH2, TEC1, CDC24, SAP10, ALS9, SNF1, SPO72 and BDF1, and the down-regulation of RAD32, IPF3636 and UBI4 resulted in stronger virulence and invasiveness in the resistant isolates compared with susceptible ones. These findings provide a link between the expression of virulence genes and development of resistance during C. albicans infection in bone marrow transplant (BMT) patients, where C. albicans induces hyphal formation and expression change in multiple virulence factors.

  17. The MP65 gene is required for cell wall integrity, adherence to epithelial cells and biofilm formation in Candida albicans

    Directory of Open Access Journals (Sweden)

    Girolamo Antonietta

    2011-05-01

    Full Text Available Abstract Background The MP65 gene of Candida albicans (orf19.1779 encodes a putative β-glucanase mannoprotein of 65 kDa, which plays a main role in a host-fungus relationship, morphogenesis and pathogenicity. In this study, we performed an extensive analysis of a mp65Δ mutant to assess the role of this protein in cell wall integrity, adherence to epithelial cells and biofilm formation. Results The mp65Δ mutant showed a high sensitivity to a range of cell wall-perturbing and degrading agents, especially Congo red, which induced morphological changes such as swelling, clumping and formation of hyphae. The mp65Δ mutant showed an activation of two MAPKs (Mkc1p and Cek1p, a high level of expression of two stress-related genes (DDR48 and SOD5, and a modulated expression of β-glucan epitopes, but no gross changes in cell wall polysaccharide composition. Interestingly, the mp65Δ mutant displayed a marked reduction in adhesion to BEC and Caco-2 cells and severe defects in biofilm formation when compared to the wild type. All of the mentioned properties were totally or partially recovered in a revertant strain, demonstrating the specificity of gene deletion. Conclusions We demonstrate that the MP65 gene of Candida albicans plays a significant role in maintaining cell wall integrity, as well as in adherence to epithelia and biofilm formation, which are major virulence attributes of this fungus.

  18. C. albicans Growth, Transition, Biofilm Formation, and Gene Expression Modulation by Antimicrobial Decapeptide KSL-W

    Science.gov (United States)

    2013-11-07

    lies in the pos- sible resistance of microorganisms to conventional anti- microbial strategies used against microbial pathogens in both agriculture ...a critical concentration [45]. Further studies are thus warranted to shed light on the fungicidal mechanism of KSL-W. C. albicans growth and...control in agriculture . J Sci Food Agric 2013, 93:1525–1536. 27. Dhople V, Krukemeyer A, Ramamoorthy A: The human beta-defensin-3, an antibacterial

  19. Lipase Gene Expression of Resistant and Sensitive Candida Albicans to Fluconazole Isolated from Patients Suffering from Oral Candidiasis and Vaginal Candidiasis

    Directory of Open Access Journals (Sweden)

    NasrollahiOmran, A. (PhD

    2015-01-01

    Full Text Available Background and Objective: With the development of drug resistance in strains of fungi, there is a considerable resistance of Candida albicans strains to fluconazole. Molecular studies are developing to determine the relationship of such a drug resistance with the increased gene expression of enzymes produced in drug-resistant Candida isolates. We aimed to evaluate the relationship between extracellular lipase gene (LIP8 expression of Candida albicans isolated from candidiasis and sensitivity or resistance to fluconazole. Material and Methods: Drug susceptibility of Candida albicans was performed in oral and vaginal candidiasis to determine the proportion of strains sensitive or resistant to fluconazole using NCCLS method. To evaluate and compare the expression of these genes in the susceptible and resistant strains, RT real-time PCR reaction was used. Results: Of 46 Candida albicans, 20 were susceptible, 12 were semi-susceptible and 14 were resistant to fluconazole. By using PCR reaction, the results showed that the expression of this gene in fluconazole-susceptible isolates was moderate, while it was high in the isolates resistant to fluconazole. Conclusion: The results of lipase gene (LIP8 expression showed that the additional expression of some genes of the enzymes responsible for virulence of Candida may also play a role in resistance to fluconazole.

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

    Science.gov (United States)

    Bahn, Y S; Sundstrom, P

    2001-05-01

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

  1. Deletion of the SSK1 response regulator gene in Candida albicans contributes to enhanced killing by human polymorphonuclear neutrophils.

    Science.gov (United States)

    Du, Chen; Calderone, Richard; Richert, John; Li, Dongmei

    2005-02-01

    The isolation and partial functional characterization of the two-component response regulator SSK1 gene of Candida albicans was previously reported. Compared to wild-type (CAF2-1) and gene-reconstituted (SSK23) strains, the ssk1 null strain (SSK21) was avirulent in a murine model of hematogenously disseminated candidiasis and less able to adhere to human esophageal cells. More recent data indicate that SSK21 is sensitive to 4 to 8 mM H(2)O(2) in vitro than CAF2-1 and SSK23. Furthermore, microarray studies indicate that the regulation of two classes of genes, those encoding cell wall functions and stress adaptation, are altered in the ssk1 mutant. In the present study, the susceptibility of strains CAF2-1, SSK21, and SSK23 to killing by human polymorphonuclear neutrophils (PMNs) was assessed. Results are also described for a newly constructed ssk1 mutant (SSK24) in which the URA3 gene is integrated into its native locus. Our results indicate that killing of SSK21 and SSK24 was significantly greater than that of CAF2-1 and SSK23 (P killing activity of human PMNs, we compared the signal transduction activity and the inflammatory response gene profiles of PMNs infected with either the wild type or the ssk1 mutant. Phosphorylation of the mitogen-activated protein kinases p42/44 and p38 from neutrophils infected with either CAF2-1 (wild type) or SSK21 (ssk1/ssk1) was similar, while expression and phosphorylation of the JNK mitogen-activated protein kinase was not observed following infection with either strain. On the other hand, we observed an upregulation of seven inflammatory response genes in PMNs infected with the SSK21 mutant only, while an increase in interleukin-10 expression was measured in PMNs infected with either strain. Downregulation of interleukin-2 was observed in PMNs infected with either strain. Verification of the transcriptional profiling was obtained by reverse transcription-PCR for three of the genes that were upregulated in neutrophils infected

  2. [Investigation of mutations in transcription factors of efflux pump genes in fluconazole-resistant Candida albicans strains overexpressing the efflux pumps].

    Science.gov (United States)

    Kalkandelen, Kemal Turan; Doluca Dereli, Mine

    2015-10-01

    In recent years, a significant rise in the number of immunocompromised patients have been observed due to cancer chemotherapy, organ transplantation and HIV infection. As a result of this, the frequency of Candida albicans infections in the clinics have been increased. Fluconazole, as being a well tolerated, easy to use drug with minor side effects, is often the first choice antifungal agent for this patient group, both for therapy and prophylaxis. Especially the long-term use of this drug, causes the selection of resistant strains and leads to the development of fluconazole resistance. The most frequently observed resistance mechanism against fluconazole in C.albicans strains is the transportation of the drug out of the cell via efflux pumps. The efflux pumps mainly involved are Cdr1, Cdr2 ve Mdr1 encoded by CDR1, CDR2 and MDR1 genes. It has been shown that, the overexpression of these efflux pump genes was caused by functional mutations in TAC1 and MRR1 genes which encode the transcription factors Tac1p and Mrr1p. This study was aimed to analyze TAC1 and MRR1 genes of 15 C.albicans strains which consist of six fluconazole-susceptible, four susceptible with trailing effect and five fluconazole-resistant isolates plus one resistant strain (DSY292), known to overexpress Mdr1 efflux pump due to P683H mutation in MRR1 gene and one fluconazole-sensitive ATCC 14053 C.albicans strain in terms of mutations with polymerase chain reaction and sequence analysis. Two of the fluconazole-resistant isolates which had overexpression of Cdr1 and Cdr2 pumps known to have overexpression of TAC1 gene, revealed R673Q and A736V mutations. A P683H point mutation, that overexpressed the Mdr1 pump was detected in a fluconazole-resistant strain, which was known to cause MRR1 overexpression. In conclusion, mutations in the transcription factors of the efflux pump genes may play an important role in the resistance against fluconazole among our selected C.albicans strains.

  3. 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.

    Science.gov (United States)

    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.

  4. Disruption of each of the secreted aspartyl proteinase genes SAP1, SAP2, and SAP3 of Candida albicans attenuates virulence.

    OpenAIRE

    Hube, B.; Sanglard, D; Odds, F C; Hess, D; Monod, M; Schäfer, W.; Brown, A J; Gow, N A

    1997-01-01

    Secreted aspartyl proteinases (Saps), encoded by a gene family with at least nine members (SAP1 to SAP9), are one of the most discussed virulence factors produced by the human pathogen Candida albicans. In order to study the role of each Sap isoenzyme in pathogenicity, we have constructed strains which harbor mutations at selected SAP genes. SAP1, SAP2, and SAP3, which are regulated differentially in vitro, were mutated by targeted gene disruption. The growth rates of all homozygous null muta...

  5. Disruption of the Candida albicans TPS1 Gene Encoding Trehalose-6-Phosphate Synthase Impairs Formation of Hyphae and Decreases Infectivity†

    Science.gov (United States)

    Zaragoza, Oscar; Blazquez, Miguel A.; Gancedo, Carlos

    1998-01-01

    The TPS1 gene from Candida albicans, which encodes trehalose-6-phosphate synthase, has been cloned by functional complementation of a tps1 mutant from Saccharomyces cerevisiae. In contrast with the wild-type strain, the double tps1/tps1 disruptant did not accumulate trehalose at stationary phase or after heat shock. Growth of the tps1/tps1 disruptant at 30°C was indistinguishable from that of the wild type. However, at 42°C it did not grow on glucose or fructose but grew normally on galactose or glycerol. At 37°C, the yeast-hypha transition in the mutant in glucose-calf serum medium did not occur. During growth at 42°C, the mutant did not form hyphae in galactose or in glycerol. Some of the growth defects observed may be traced to an unbalanced sugar metabolism that reduces the cellular content of ATP. Mice inoculated with 106 CFU of the tps1/tps1 mutant did not show visible symptoms of infection 16 days after inoculation, while those similarly inoculated with wild-type cells were dead 12 days after inoculation. PMID:9683476

  6. Rapid detection and identification of Candida albicans and Torulopsis (Candida) glabrata in clinical specimens by species-specific nested PCR amplification of a cytochrome P-450 lanosterol-alpha-demethylase (L1A1) gene fragment.

    Science.gov (United States)

    Burgener-Kairuz, P; Zuber, J P; Jaunin, P; Buchman, T G; Bille, J; Rossier, M

    1994-08-01

    PCR of a Candida albicans cytochrome P-450 lanosterol-alpha-demethylase (P450-L1A1) gene segment is a rapid and sensitive method of detection in clinical specimens. This enzyme is a target for azole antifungal action. In order to directly detect and identify the clinically most important species of Candida, we cloned and sequenced 1.3-kbp fragments of the cytochrome P450-L1A1 genes from Torulopsis (Candida) glabrata and from Candida krusei. These segments were compared with the published sequences from C. albicans and Candida tropicalis. Amplimers for gene sequences highly conserved throughout the fungal kingdom were first used; positive PCR results were obtained for C. albicans, T. glabrata, C. krusei, Candida parapsilosis, C. tropicalis, Cryptococcus neoformans, and Trichosporon beigelii DNA extracts. Primers were then selected for a highly variable region of the gene, allowing the species-specific detection from purified DNA of C. albicans, T. glabrata, C. krusei, and C. tropicalis. The assay sensitivity as tested for C. albicans in seeded clinical specimens such as blood, peritoneal fluid, or urine was 10 to 20 cells per 0.1 ml. Compared with results obtained by culture, the sensitivity, specificity, and efficiency of the species-specific nested PCR tested with 80 clinical specimens were 71, 95, and 83% for C. albicans and 100, 97, and 98% for T. glabrata, respectively.

  7. Prostaglandins from Cytosolic Phospholipase A2α/Cyclooxygenase-1 Pathway and Mitogen-activated Protein Kinases Regulate Gene Expression in Candida albicans-infected Macrophages.

    Science.gov (United States)

    Yun, Bogeon; Lee, HeeJung; Jayaraja, Sabarirajan; Suram, Saritha; Murphy, Robert C; Leslie, Christina C

    2016-03-25

    In Candida albicans-infected resident peritoneal macrophages, activation of group IVA cytosolic phospholipase A2(cPLA2α) by calcium- and mitogen-activated protein kinases triggers the rapid production of prostaglandins I2 and E2 through cyclooxygenase (COX)-1 and regulates gene expression by increasing cAMP. InC. albicans-infected cPLA2α(-/-)or COX-1(-/-)macrophages, expression ofI l10,Nr4a2, and Ptgs2 was lower, and expression ofTnfα was higher, than in wild type macrophages. Expression was reconstituted with 8-bromo-cAMP, the PKA activator 6-benzoyl-cAMP, and agonists for prostaglandin receptors IP, EP2, and EP4 in infected but not uninfected cPLA2α(-/-)or COX-1(-/-)macrophages. InC. albicans-infected cPLA2α(+/+)macrophages, COX-2 expression was blocked by IP, EP2, and EP4 receptor antagonists, indicating a role for both prostaglandin I2 and E2 Activation of ERKs and p38, but not JNKs, by C. albicansacted synergistically with prostaglandins to induce expression of Il10,Nr4a2, and Ptgs2. Tnfα expression required activation of ERKs and p38 but was suppressed by cAMP. Results using cAMP analogues that activate PKA or Epacs suggested that cAMP regulates gene expression through PKA. However, phosphorylation of cAMP-response element-binding protein (CREB), the cAMP-regulated transcription factor involved inIl10,Nr4a2,Ptgs2, andTnfα expression, was not mediated by cAMP/PKA because it was similar inC. albicans-infected wild type and cPLA2α(-/-)or COX-1(-/-)macrophages. CREB phosphorylation was blocked by p38 inhibitors and induced by the p38 activator anisomycin but not by the PKA activator 6-benzoyl-cAMP. Therefore, MAPK activation inC. albicans-infected macrophages plays a dual role by promoting the cPLA2α/prostaglandin/cAMP/PKA pathway and CREB phosphorylation that coordinately regulate immediate early gene expression.

  8. Evaluation of Susceptibility of Strains of Candida Albicans Isolated from AIDS Patients to Fluconazole and Determination of CDR2 Resistance Gene in Resistant Strains by RT-PCR Method

    Directory of Open Access Journals (Sweden)

    E Farahbakhsh

    2011-08-01

    Full Text Available Introduction & Objective: Nowadays, opportunistic fungi especially Candida albicans are the most common cause of life-threatening infections in immunodeficiency patients. Increasing Azole-resistant strains of C.albicans are a main problem in human immunodeficiency virus-infected patients. The aim of this study was to evaluate the CDR2 gene in C.albicans azole resistant strains, isolated from AIDS patients with oropharyngeal candidiasis by RT-PCR method. Materials & Methods: The present experimental study was conducted at Tarbiat Modares University of Medical Sciences in 2009. C. albicans isolates from HIV infected patients were identified by standard procedures, including germ tube formation, clamidospor and color of colonies on CHROM agar. At first, susceptibility of C. albicans isolates was assessed by disk diffusion agar technique. Then, CDR2 resistance gene was analyzed by RT-PCR and electrophoresis of the PCR products. Finally, patterns of the resulted bands were compared with standard fluconazole resistant strains. The collected data was analyzed using the SPSS software. Results: The results of drug sensitivity of 66 C. albicans isolates from AIDS patients revealed that 62.6% were susceptible, 8.6% were susceptible-dose dependent (SDD and 28.7% were resistant. In RT-PCR analysis, 6% of patients had the CDR2 gene. Conclusion: The use of phenotypic methods like disk diffusion agar, which is cheaper, along with genotypic methods, like RT-PCR, which provide the possibility of studying the mechanism of drug resistance, is recommended.

  9. Synergistic effect of fluconazole and doxycycline against Candida albicans biofilms resulting from calcium fluctuation and downregulation of fluconazole-inducible efflux pump gene overexpression.

    Science.gov (United States)

    Gao, Yuan; Li, Hui; Liu, Shuyuan; Zhang, Xiang; Sun, Shujuan

    2014-07-01

    Candida albicans biofilms are intrinsically resistant to antimicrobial agents. Previous work demonstrated that the antifungal activity of fluconazole against C. albicans biofilms is notably enhanced by doxycycline. In order to explore the synergistic mechanism of fluconazole and doxycycline, we investigated the changes of efflux pump gene expression, intracellular calcium concentration and cell cycle distribution after drug intervention in this study. The expression levels of CDR1, CDR2 and MDR1 were determined by real-time PCR, and the results showed that fluconazole alone could stimulate the high expression of CDR1, CDR2 and MDR1, and the combination of doxycycline and fluconazole downregulated the gene overexpression induced by fluconazole. Intracellular calcium concentration was determined using Fluo-3/AM by observing the fluorescence with flow cytometry. A calcium fluctuation, which started 4 h and peaked 8 h after the treatment with fluconazole, was observed. The combined drugs also initiated a calcium fluctuation after 4 h treatment and showed a peak at 16 h, and the peak was higher than that stimulated by fluconazole alone. The cell cycle was measured using flow cytometry. Fluconazole alone and the combined drugs both induced a reduction in the percentages of S-phase cells and an elevation in the percentages of cells in the G2/M phase. The results of this research showed that the synergism of fluconazole and doxycycline against C. albicans biofilms is associated with blockade of the efflux pump genes CDR1, CDR2 and MDR1, and stimulation of high intracellular calcium concentration. The findings of this study are of great significance in the search for new antifungal mechanisms.

  10. White-opaque Switching in Different Mating Type-like Locus Gene Types of Clinical Candida albicans Isolates

    Directory of Open Access Journals (Sweden)

    Hou-Min Li

    2016-01-01

    Conclusions: From these analyses, there were comparatively more C. albicans strains classified into serotype B, and the frequency of opaque phase strains was significant in the clinical isolates from China. Genetic, phenotypic, or drug susceptibility patterns were not significantly different from previous studies. MTL a/α isolates could also undergo WO switching which facilitates their survival.

  11. Candida albicans AGE3, the ortholog of the S. cerevisiae ARF-GAP-encoding gene GCS1, is required for hyphal growth and drug resistance.

    Directory of Open Access Journals (Sweden)

    Thomas Lettner

    Full Text Available 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 age3Delta 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 age3Delta cells shows a wild-type-like polarization pattern of the actin cytoskeleton and lipid rafts. Moreover, age3Delta 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 age3Delta 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 age3Delta cells to polarize the actin cytoskeleton and possibly of inefficient endocytosis. The high susceptibility of age3Delta cells to azoles is not caused by inefficient transport of efflux pumps to the cell membrane. A possible role of a vacuolar defect of age3Delta 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

  12. Mucins Suppress Virulence Traits of Candida albicans

    Science.gov (United States)

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

    2014-01-01

    ABSTRACT Candida albicans is the most prevalent fungal pathogen of humans, causing a variety of diseases ranging from superficial mucosal infections to deep-seated systemic invasions. Mucus, the gel that coats all wet epithelial surfaces, accommodates C. albicans as part of the normal microbiota, where C. albicans resides asymptomatically in healthy humans. Through a series of in vitro experiments combined with gene expression analysis, we show that mucin biopolymers, the main gel-forming constituents of mucus, induce a new oval-shaped morphology in C. albicans in which a range of genes related to adhesion, filamentation, and biofilm formation are downregulated. We also show that corresponding traits are suppressed, rendering C. albicans impaired in forming biofilms on a range of different synthetic surfaces and human epithelial cells. Our data suggest that mucins can manipulate C. albicans physiology, and we hypothesize that they are key environmental signals for retaining C. albicans in the host-compatible, commensal state. PMID:25389175

  13. Genome-wide gene expression profiling and a forward genetic screen show that differential expression of the sodium ion transporter Ena21 contributes to the differential tolerance of Candida albicans and Candida dubliniensis to osmotic stress.

    LENUS (Irish Health Repository)

    Enjalbert, Brice

    2009-04-01

    Candida albicans is more pathogenic than Candida dubliniensis. However, this disparity in virulence is surprising given the high level of sequence conservation and the wide range of phenotypic traits shared by these two species. Increased sensitivity to environmental stresses has been suggested to be a possible contributory factor to the lower virulence of C. dubliniensis. In this study, we investigated, in the first comparison of C. albicans and C. dubliniensis by transcriptional profiling, global gene expression in each species when grown under conditions in which the two species exhibit differential stress tolerance. The profiles revealed similar core responses to stresses in both species, but differences in the amplitude of the general transcriptional responses to thermal, salt and oxidative stress. Differences in the regulation of specific stress genes were observed between the two species. In particular, ENA21, encoding a sodium ion transporter, was strongly induced in C. albicans but not in C. dubliniensis. In addition, ENA21 was identified in a forward genetic screen for C. albicans genomic sequences that increase salt tolerance in C. dubliniensis. Introduction of a single copy of CaENA21 was subsequently shown to be sufficient to confer salt tolerance upon C. dubliniensis.

  14. Role of Bcr1-activated genes Hwp1 and Hyr1 in Candida albicans oral mucosal biofilms and neutrophil evasion.

    Science.gov (United States)

    Dwivedi, Prabhat; Thompson, Angela; Xie, Zhihong; Kashleva, Helena; Ganguly, Shantanu; Mitchell, Aaron P; Dongari-Bagtzoglou, Anna

    2011-01-25

    Candida albicans triggers recurrent infections of the oropharyngeal mucosa that result from biofilm growth. Prior studies have indicated that the transcription factor Bcr1 regulates biofilm formation in a catheter model, both in vitro and in vivo. We thus hypothesized that Bcr1 plays similar roles in the formation of oral mucosal biofilms and tested this hypothesis in a mouse model of oral infection. We found that a bcr1/bcr1 mutant did not form significant biofilm on the tongues of immunocompromised mice, in contrast to reference and reconstituted strains that formed pseudomembranes covering most of the tongue dorsal surface. Overexpression of HWP1, which specifies an epithelial adhesin that is under the transcriptional control of Bcr1, partly but significantly rescued the bcr1/bcr1 biofilm phenotype in vivo. Since HWP1 overexpression only partly reversed the biofilm phenotype, we investigated whether additional mechanisms, besides adhesin down-regulation, were responsible for the reduced virulence of this mutant. We discovered that the bcr1/bcr1 mutant was more susceptible to damage by human leukocytes when grown on plastic or on the surface of a human oral mucosa tissue analogue. Overexpression of HYR1, but not HWP1, significantly rescued this phenotype. Furthermore a hyr1/hyr1 mutant had significantly attenuated virulence in the mouse oral biofilm model of infection. These discoveries show that Bcr1 is critical for mucosal biofilm infection via regulation of epithelial cell adhesin and neutrophil function.

  15. Endoftalmite por Candida albicans Candida albicans endophthalmitis

    Directory of Open Access Journals (Sweden)

    Pedro Duraes Serracarbassa

    2003-10-01

    Full Text Available O autor descreve os aspectos epidemiológicos, histopatológicos e clínicos da endoftalmite endógena por Candida albicans. Apresenta ainda novos métodos diagnósticos e opções terapêuticas utilizadas no tratamento das infecções fúngicas intra-oculares, por meio de revisão bibliográfica.The author describes epidemiological, histopathological and clinical aspects of endogenous Candida albicans endophthalmitis. He also presents new diagnostic methods and therapeutical options to treat intraocular fungal infections, based on literature review.

  16. Chronic Candida albicans Meningitis in a 4-Year-Old Girl with a Homozygous Mutation in the CARD9 Gene (Q295X).

    Science.gov (United States)

    Herbst, Martin; Gazendam, Roel; Reimnitz, Denise; Sawalle-Belohradsky, Julie; Groll, Andreas; Schlegel, Paul-Gerhardt; Belohradsky, Bernd; Renner, Ellen; Klepper, Jörg; Grimbacher, Bodo; Kuijpers, Taco; Liese, Johannes

    2015-09-01

    A 4-year-old Turkish girl of consanguineous parents was hospitalized for the evaluation of headaches and recurrent febrile episodes of unknown origin. Her medical history was unremarkable except for a few episodes of uncomplicated oral thrush. Meningitis was diagnosed, and Candida albicans was the only pathogen identified by polymerase chain reaction and culture. Despite systemic antifungal multidrug therapy, a prolonged course of 16 months of therapy was necessary to clear C. albicans from the cerebrospinal fluid. Molecular genetic analysis revealed a homozygous caspase recruitment domain 9 (CARD9) mutation (Q295X), which was reported to predispose to chronic mucocutaneous candidiasis. Immunologic workup excluded predisposing B-cell and T-cell defects. In addition, T cells producing interleukin-17 were repeatedly measured within the normal range. Analyses of neutrophils demonstrated normal nicotinamide adenine dinucleotide phosphate oxidase activity in response to various stimuli including Staphylococcus aureus and C. albicans. Additional neutrophilic functional testing, however, showed a decreased cytotoxicity to nonopsonized C. albicans, indicating an impaired killing mechanism against Candida spp. independent from the production of reactive oxygen species by the nicotinamide adenine dinucleotide phosphate oxidase system. Because this defect was only demonstrated in the absence of opsonins, it might especially predispose to chronic C. albicans infections in the central nervous system where opsonin concentrations are usually low. We, therefore, suggest that due to an additional neutrophil dependent defect CARD9 deficiency predisposes not only to chronic mucocutaneous candidiasis, but also to invasive chronic Candida infections, especially of the central nervous system.

  17. Candida albicans infection of Caenorhabditis elegans induces antifungal immune defenses.

    Directory of Open Access Journals (Sweden)

    Read Pukkila-Worley

    2011-06-01

    Full Text Available Candida albicans yeast cells are found in the intestine of most humans, yet this opportunist can invade host tissues and cause life-threatening infections in susceptible individuals. To better understand the host factors that underlie susceptibility to candidiasis, we developed a new model to study antifungal innate immunity. We demonstrate that the yeast form of C. albicans establishes an intestinal infection in Caenorhabditis elegans, whereas heat-killed yeast are avirulent. Genome-wide, transcription-profiling analysis of C. elegans infected with C. albicans yeast showed that exposure to C. albicans stimulated a rapid host response involving 313 genes (124 upregulated and 189 downregulated, ~1.6% of the genome many of which encode antimicrobial, secreted or detoxification proteins. Interestingly, the host genes affected by C. albicans exposure overlapped only to a small extent with the distinct transcriptional responses to the pathogenic bacteria Pseudomonas aeruginosa or Staphylococcus aureus, indicating that there is a high degree of immune specificity toward different bacterial species and C. albicans. Furthermore, genes induced by P. aeruginosa and S. aureus were strongly over-represented among the genes downregulated during C. albicans infection, suggesting that in response to fungal pathogens, nematodes selectively repress the transcription of antibacterial immune effectors. A similar phenomenon is well known in the plant immune response, but has not been described previously in metazoans. Finally, 56% of the genes induced by live C. albicans were also upregulated by heat-killed yeast. These data suggest that a large part of the transcriptional response to C. albicans is mediated through "pattern recognition," an ancient immune surveillance mechanism able to detect conserved microbial molecules (so-called pathogen-associated molecular patterns or PAMPs. This study provides new information on the evolution and regulation of the innate

  18. Diversities of interaction of murine macrophages with three strains of Candida albicans represented by MyD88, CARD9 gene expressions and ROS, IL-10 and TNF-α secretion

    OpenAIRE

    Zhang, Xiaohuan; Ge, Yanping; Li, Wenqing; Hu, Yan

    2014-01-01

    Aim: To explore the mechanisms underlying the different responses of macrophages to distinct Candida albicans strains. Methods: Bone marrow was collected from mice. Macrophages were independently incubated with 3 Candida albicans strains. Results: MyD88 expression in Candida albicans 3683 group was significantly higher than that in Candida albicans 3630 group and Candida albicans SC5314 group, and marked difference was also observed between later two groups (P

  19. Candida albicans versus Candida dubliniensis: Why Is C. albicans More Pathogenic?

    LENUS (Irish Health Repository)

    Moran, Gary P

    2012-01-01

    Candida albicans and Candida dubliniensis are highly related pathogenic yeast species. However, C. albicans is far more prevalent in human infection and has been shown to be more pathogenic in a wide range of infection models. Comparison of the genomes of the two species has revealed that they are very similar although there are some significant differences, largely due to the expansion of virulence-related gene families (e.g., ALS and SAP) in C. albicans, and increased levels of pseudogenisation in C. dubliniensis. Comparative global gene expression analyses have also been used to investigate differences in the ability of the two species to tolerate environmental stress and to produce hyphae, two traits that are likely to play a role in the lower virulence of C. dubliniensis. Taken together, these data suggest that C. dubliniensis is in the process of undergoing reductive evolution and may have become adapted for growth in a specialized anatomic niche.

  20. Mutation analysis of ERG 11 gene in Candida albicans isolates from patients with acquired immunodeficiency syndrome (AIDS)%艾滋病患者白念珠菌ERG11基因突变的研究

    Institute of Scientific and Technical Information of China (English)

    王丽; 惠艳; 张丽娟; 张巧巧; 邓淑文; 帕丽达·阿布利孜; 王慧

    2012-01-01

    目的 探讨艾滋病患者的白念珠菌唑类耐药株中唑类抗真菌药物(氟康唑、伊曲康唑、伏立康唑)的作用靶位基因ERG 11基因突变与耐药的关系.方法 用PCR对临床分离的93株白念珠菌的Erg11基因进行扩增、测序,DNAman软件将测序结果与基因库中的X13296进行比对,将突变碱基翻译为氨基酸,确定是否发生错义突变.结果 共检出40个碱基突变位点,包括27个同义突变位点和13个错义突变位点.耐一种药物的突变菌株中每株菌只发生一处错义突变或无错义突变,而耐二种或三种药物的菌株中每株菌还可以同时出现两处或三处错义突变.结论 ERG 11基因错义突变与白念珠菌耐药有关.%Objective To investigate the relationship between the mutation of ERG11 gene,a target of azole antifungal drugs (fluconazole,itraconazole,voriconazole),and azole-resistance in Candida albicans isolates from patients with AIDS.Methods Ninety-three Candida albicans strains were isolated from patients with AIDS.DNA was extracted from these isolates,and ERG11 gene was amplified by PCR followed by bidirectional sequencing.DNAman software was used to compare the resultant sequence with the reference sequence of ERG11 gene (GenBank accession no.X13296).Then,different base sequences were translated into amino acid sequences to determine whether missense mutations occured.Results A total of 40 mutation sites were identified in these isolates,including 27 silent mutations and 13 missense mutations.One or no missense mutation was detected in Candida albicans strains resistant to 1 antifungal agent,while those resistant to 2 or 3 antifungal agents simultaneously harbored 2 or 3 missense mutations.Conclusion The missense mutations in ERG11 gene are probably connected with azole resistance in Candida albicans.

  1. High Virulence and Antifungal Resistance in Clinical Strains of Candida albicans

    OpenAIRE

    Monroy-Pérez, Eric; Paniagua-Contreras, Gloria Luz; Rodríguez-Purata, Pamela; Vaca-Paniagua, Felipe; Vázquez-Villaseñor, Marco; Díaz-Velásquez, Clara; Uribe-García, Alina; Vaca, Sergio

    2016-01-01

    Antifungal resistance and virulence properties of Candida albicans are a growing health problem worldwide. To study the expression of virulence and azole resistance genes in 39 clinical strains of C. albicans, we used a model of infection of human vaginal epithelial cells with C. albicans strains isolated from Mexican women with vulvovaginal candidiasis (VVC). The strains were identified by PCR amplification of the ITS1 and ITS2 regions of rRNA. The detection and expression of virulence genes...

  2. Differentially expressed genes of Candida albicans under starvation conditions%饥饿状态下白色念珠菌差异表达基因的研究

    Institute of Scientific and Technical Information of China (English)

    宁杨; 杜宇; 凌均棨

    2016-01-01

    Objective To explore the gene expression during induction and formation of starvation state of Candida albicans(C.albicans). Methods C.albicans American Type Culture Collection(ATCC) 10231 was cultured and induced into starvation phase. After induction for 0,12,24,and 48 h,the fungal cells were collected. Total RNA was extracted and microarrays were used to identify the gene expression changes under starvation conditions. T⁃test was used to statistically analyze the data of different time points. Results Statistical analysis demonstrated that 14.45%to 29.13%of gene expression has changed during the induction into starvation conditions(P<0.05),these genes are related with many biologic pathways including amino acid metabolism,carbohydrate metabolism,lipid metabolism,nucleic acid metabolism and cell cycles. Especially,the differentially expressed genes included the down⁃regulation of alanine metabolism related genes,ATP synthesis related gene SDH4,mitosis related gene PRE1,and exopolymeric matrix production gene GCA1,and up⁃regulation of PXA2 and VPS34. Conclusions During the induction into starvation conditions,the genes related with metabolic and proliferative activities were down⁃regulated,while the genes related with environment and drug resistance were up⁃regulated. These changes may be contributed to maintain the survival and pathogenic capabilities of C.albicans under starvation conditions.%目的:探讨白色念珠菌饥饿状态的形成机制及差异表达基因。方法将白色念珠菌(ATCC 10231)诱导进入厌氧饥饿状态,收集进入饥饿状态0、12、24和48 h的白色念珠菌,提取总RNA后采用全基因组表达谱芯片技术分析基因的差异表达。采用t检验对不同时间点的基因表达状况进行统计分析。结果统计分析显示,白色念珠菌诱导进入饥饿状态过程中,14.45%~29.13%的基因表达发生改变(P<0.05),涉及氨基酸代谢、糖代谢、脂类代谢、核酸代

  3. 白念珠菌基因组结构与遗传、致病相关基因%Progresses in genomic constructure, heredity- and virulence-related genes of Candida albicans

    Institute of Scientific and Technical Information of China (English)

    米霞; 郑和义

    2010-01-01

    Candida albicans, an important opportunistic pathogen, lives as a harmless commensal in multiple organs of human. It can cause oral and vaginal candidiasis, even life-threatening systemic infection in patients with hypoimmunity or malignancy. The mortality rate of candidia infection has been remaining high because of difficulty in early diagnosis of systemic candidiasis, increasing resistance to antifungals and lack of efficient antifungal agents. Therefore, studies on Candida albicans genome structure, sequence and gene function have become more and more important for the guidance on clinical diagnosis and treatment of candidiasis.%白念珠菌是一种重要的机会致病菌,在人的多个系统或器官与宿主共栖生存,可导致口腔和阴道念珠菌病,在免疫力低下或患严重疾病的患者,可引起系统疾病.由于早期准确诊断系统性念珠菌病存在困难,合适有效的抗真菌药物数量有限,病原体的耐药性增加,导致系统性念珠菌病病死率居高不下.因此,对白念珠菌基因组序列及结构、功能的研究对指导临床的诊断和治疗显得尤为重要.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 (palbicans expressed virulence factors in biofilms that could contribute to peri-implantitis, but this was dependent on associated bacterial species.

  6. Detection of point mutations in genes related to fluconazole resistance in Candida albicans%白念珠菌耐氟康唑相关基因点突变的检测

    Institute of Scientific and Technical Information of China (English)

    景伟芳; 李春莉; 郭雅莉; 刘原君; 亓玉青; 刘全忠; 王惠平

    2013-01-01

    Objective To investigate the relationship of point mutations in ERG11,TAC1,MRR1 and UPC2 genes to fluconazole resistance in Candida albicans.Methods This study included 11 fluconazole-resistant Candida albicans strains.DNA was extracted from these Candida isolates by urea pyrolysis method.PCR was carried out to amplify the full-length EGR11 gene,as well as the corresponding fragments of TAC1,MRR1 and UPC2 genes followed by DNA sequencing.Results Eight mutations were detected in the ERG11 gene,including D116E,Y132H,Y132F,K143Q,T229A,E266D,G448E and G464S.Among them,K143Q was a novel mutation and had not been reported.A G648D mutation was detected in the UpC2 gene.No mutations were detected in the TAC1 or MRR1 gene.Conclusions There is a definite association between fluconazole resistance and ERG11 mutations,while further research is warranted to clarify the relationship between the mutations of TAC1,MRR1,UPC2 genes and resistance to fluconazole.%目的 探讨ERG11、TAC1、MRR1和UPC2点突变与白念珠菌氟康唑耐药之间的关系.方法 收集耐氟康唑的白念珠菌,尿素裂解法提取DNA,PCR扩增ERG11基因全长以及TAC1、MRR1和UPC2基因的相应片段,送交测序.结果 ERG11基因发现8种点突变,即D116E、Y132H、Y132F、K143Q、T229A、E266D、G448E和G464S,其中K143Q此前未见文献报道.UPC2基因发现1种点突变G648D.TAC1和MRR1基因中均未检测到相应点突变.结论 ERG11点突变与耐药的关系比较明确,TAC1、MRR1和UPC2点突变与耐药的关系有待进一步研究.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  9. Comparative genomics of the fungal pathogens Candida dubliniensis and Candida albicans.

    LENUS (Irish Health Repository)

    Jackson, Andrew P

    2009-12-01

    Candida dubliniensis is the closest known relative of Candida albicans, the most pathogenic yeast species in humans. However, despite both species sharing many phenotypic characteristics, including the ability to form true hyphae, C. dubliniensis is a significantly less virulent and less versatile pathogen. Therefore, to identify C. albicans-specific genes that may be responsible for an increased capacity to cause disease, we have sequenced the C. dubliniensis genome and compared it with the known C. albicans genome sequence. Although the two genome sequences are highly similar and synteny is conserved throughout, 168 species-specific genes are identified, including some encoding known hyphal-specific virulence factors, such as the aspartyl proteinases Sap4 and Sap5 and the proposed invasin Als3. Among the 115 pseudogenes confirmed in C. dubliniensis are orthologs of several filamentous growth regulator (FGR) genes that also have suspected roles in pathogenesis. However, the principal differences in genomic repertoire concern expansion of the TLO gene family of putative transcription factors and the IFA family of putative transmembrane proteins in C. albicans, which represent novel candidate virulence-associated factors. The results suggest that the recent evolutionary histories of C. albicans and C. dubliniensis are quite different. While gene families instrumental in pathogenesis have been elaborated in C. albicans, C. dubliniensis has lost genomic capacity and key pathogenic functions. This could explain why C. albicans is a more potent pathogen in humans than C. dubliniensis.

  10. Analysis of genital Candida albicans infection by rapid microsatellite markers genotyping

    Institute of Scientific and Technical Information of China (English)

    SHI Wei-min; MEI Xing-yu; GAO Fei; HUO Ke-ke; SHEN Liang-liang; QIN Hai-hong; WU Zhou-wei; ZHENG Jie

    2007-01-01

    Background Candida albicans (C. albicans) infection, often occurring in genital candidiasis, has increased dramatically recently. Developing an efficient C. albicans typing method may contribute to understanding its epidemiological characteristics and guiding efficient treatment. We used rapid microsatellite genotyping assay for interstrain differentiation of C. albicans isolates and explored some characteristics of its spread.Methods DNA was extracted from C. albicans isolates from gentalia, recta and mouths of 39 female cases and 27 male cases of genital candidiasis. Three fluorescent primers for the microsatellite markers in conserved genes (CDC3, EF3and HIS3) of C. albicans were used to amplify the isolates DNA by PCR. Fluorescent signals were read with an automatic sequencer and analyzed with GeneScan software.Results Analysis of the three microsatellites markers showed 18 gene allelic associations in genital C. albicans infected patients: 10 allelic associations in female and 11 allelic associations in male, of which 3 allelic associations shared by both genders covered 71% of infections. The most dominant allele association of pathogenic strains for both genders was 116:124, 122:131,160:200 that covered about 50% of infection. Gentalia and recta shared the same strains in 80%of female patients, but in only 3.8% of male patients. There were 2.7% female patients, but no males, with same strain in both gentalia and mouths. Five of seven genital C. albicans infected couples had the same allelic associations of which 4were the dominant pathogenic C. albicans susceptible for both genders.Conclusions The predominant allelic association of the pathogenic strain in genital C. albicans infection is 116:124,122:131, 160:200. Vaginal pathogenic strains are probably maintained from the rectal reservoir. Pathogenic strains of male patients are probably from frequent sexual intercourse. The aggressiveness of some strains varies with gender.

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

    Science.gov (United States)

    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 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.

  12. Transcriptional landscape of trans-kingdom communication between Candida albicans and Streptococcus gordonii.

    Science.gov (United States)

    Dutton, L C; Paszkiewicz, K H; Silverman, R J; Splatt, P R; Shaw, S; Nobbs, A H; Lamont, R J; Jenkinson, H F; Ramsdale, M

    2016-04-01

    Recent studies have shown that the transcriptional landscape of the pleiomorphic fungus Candida albicans is highly dependent upon growth conditions. Here using a dual RNA-seq approach we identified 299 C. albicans and 72 Streptococcus gordonii genes that were either upregulated or downregulated specifically as a result of co-culturing these human oral cavity microorganisms. Seventy-five C. albicans genes involved in responses to chemical stimuli, regulation, homeostasis, protein modification and cell cycle were significantly (P ≤ 0.05) upregulated, whereas 36 genes mainly involved in transport and translation were downregulated. Upregulation of filamentation-associated TEC1 and FGR42 genes, and of ALS1 adhesin gene, concurred with previous evidence that the C. albicans yeast to hypha transition is promoted by S. gordonii. Increased expression of genes required for arginine biosynthesis in C. albicans was potentially indicative of a novel oxidative stress response. The transcriptional response of S. gordonii to C. albicans was less dramatic, with only eight S. gordonii genes significantly (P ≤ 0.05) upregulated at least two-fold (glpK, rplO, celB, rplN, rplB, rpsE, ciaR and gat). The expression patterns suggest that signals from S. gordonii cause a positive filamentation response in C. albicans, whereas S. gordonii appears to be transcriptionally less influenced by C. albicans.

  13. Candida albicans: adapting to succeed.

    Science.gov (United States)

    Kadosh, David; Lopez-Ribot, Jose L

    2013-11-13

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

  14. Biofilm gene expression and biofilm-related genes of Candida albicans:an update%白念珠菌生物被膜的基因表达及相关基因研究进展

    Institute of Scientific and Technical Information of China (English)

    商庆华; 曹颖瑛; 苗浩; 姜远英

    2012-01-01

    Candida albicans is an opportunistic fungal pathogen with the ability to form biofilms on in-planted medical devices. Cells in biofilms display a phenotype that is markedly different from their pianktonic and free-living counterparts in both form and function. Recent advances in microarray and genetic manipulation have begun to clarify the mechanisms that govern C, albicans biofilm development and acquisition of such unique phenotype. These studies are considered to be important in finding new targets of antifungal drugs.%白念珠菌是一种条件性致病菌,可在人体植入性器械表面形成生物被膜.与浮游和以个体形式存在的白念珠菌相比,生物被膜在结构及功能上有很大差异,这种差异本质上是由基因表达决定的.近年来,研究者们试图通过芯片和基因敲除等技术手段,探索与白念珠菌生物被膜形成及耐药相关的基因,揭示其分子机制,寻找药物作用的新靶点.

  15. 白念珠菌生物膜耐药性观察及 als3基因表达与成膜相关性的初步探讨%The drug resistance of Candida albicans biofilm and the correlation of als3 gene expression and film forming

    Institute of Scientific and Technical Information of China (English)

    邓可可; 邓琦; 张坚磊; 贺小圆; 江嫣雨

    2016-01-01

    Objective To observe the biofilm structure,drug resistance and related gene expressions of clinically collected drug sensitive strains of Candida albicans ,and to explore preliminarily the film-forming related gene expressions of Candida albicans .Methods A total of 108 strains of Candida albicans from positive blood culture were obtained from Tianjing First Central Hospital from January to December in 2015 and 58 stains which were sensitive to azole drugs were selected.Sterile indwelling catheter was used to establish the Candida albicans biofilm in vitro model.The structure of Candida albicans biofilm was observed with inverted microscope.The ultrastructure was observed with transmission electron microscope.The drug sensitivity was detected by using trace liquid dilution M27-A2 scheme and the als3,xog,bg1,efg1 gene expressions were detected using polymerase chain reaction method.Paired t test was used for data analysis.Results After Candida albicans biofilm model was set up,Candida albicans cells gathering along the hyphae and forming different layers of membrane structure were observed under inverted microscope.The thickened Candida albicans cell membranes with increased mitochondria and cell activity were observed under transmission electron microscope.Drug resistances to fluconazole,voriconazole and itraconazole were increased after the biofilm formation. The minimal inhibitory concentration values of echinocandins, including caspofungin and micafungin increased at different degree,but did not achieve drug resistance.The als3 gene expressions among strains before biofilm formation were different.Candida albicans with high als3 gene expression tended to form biofilm (t= 3.645,P 0.05 ).Conclusions Drug resistances to fluconazole, voriconazole and itraconazole increase after the Candida albicans biofilm formation.But Candida albicans remains sensitive to echinocandins after the formation of biofilm.The expression of als3 gene can be used to screen Candida

  16. Candida albicans skin abscess Abscesso de pele por Candida albicans

    Directory of Open Access Journals (Sweden)

    Felipe Francisco Tuon

    2006-10-01

    Full Text Available Subcutaneous candidal abscess is a very rare infection even in immunocompromised patients. Some cases are reported when breakdown in the skin occurs, as bacterial cellulites or abscess, iatrogenic procedures, trauma and parenteral substance abuse. We describe a case of Candida albicans subcutaneous abscess without fungemia, which can be associated with central venous catheter.Abscesso subcutâneo por Candida é infecção muito rara mesmo em pacientes imunocomprometidos. Alguns casos são relatados quando ocorre dano na pele, como celulite bacteriana ou abscesso, procedimentos iatrogênicos, trauma e abuso de substância parenteral. Relatamos caso de abscesso subcutâneo por Candida albicans sem fungemia, que pode estar associado com cateter venoso central.

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

    Science.gov (United States)

    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.

  18. Transcriptomics Analysis of Candida albicans Treated with Huanglian Jiedu Decoction Using RNA-seq

    Directory of Open Access Journals (Sweden)

    Qianqian Yang

    2016-01-01

    Full Text Available Candida albicans is the major invasive fungal pathogen of humans, causing diseases ranging from superficial mucosal infections to disseminated, systemic infections that are often life-threatening. Resistance of C. albicans to antifungal agents and limited antifungal agents has potentially serious implications for management of infections. As a famous multiherb prescription in China, Huanglian Jiedu Decoction (HLJJD, Orengedokuto in Japan is efficient against Trichophyton mentagrophytes and C. albicans. But the antifungal mechanism of HLJDD remains unclear. In this study, by using RNA-seq technique, we performed a transcriptomics analysis of gene expression changes for C. albicans under the treatment of HLJDD. A total of 6057 predicted protein-encoding genes were identified. By gene expression analysis, we obtained a total of 735 differentially expressed genes (DEGs, including 700 upregulated genes and 35 downregulated genes. Genes encoding multidrug transporters such as ABC transporter and MFS transporter were identified to be significantly upregulated. Meanwhile, by pathway enrichment analysis, we identified 26 significant pathways, in which pathways of DNA replication and transporter activity were mainly involved. These results might provide insights for the inhibition mechanism of HLJDD against C. albicans.

  19. A Human-Curated Annotation of the Candida albicans Genome.

    Directory of Open Access Journals (Sweden)

    2005-07-01

    Full Text Available Recent sequencing and assembly of the genome for the fungal pathogen Candida albicans used simple automated procedures for the identification of putative genes. We have reviewed the entire assembly, both by hand and with additional bioinformatic resources, to accurately map and describe 6,354 genes and to identify 246 genes whose original database entries contained sequencing errors (or possibly mutations that affect their reading frame. Comparison with other fungal genomes permitted the identification of numerous fungus-specific genes that might be targeted for antifungal therapy. We also observed that, compared to other fungi, the protein-coding sequences in the C. albicans genome are especially rich in short sequence repeats. Finally, our improved annotation permitted a detailed analysis of several multigene families, and comparative genomic studies showed that C. albicans has a far greater catabolic range, encoding respiratory Complex 1, several novel oxidoreductases and ketone body degrading enzymes, malonyl-CoA and enoyl-CoA carriers, several novel amino acid degrading enzymes, a variety of secreted catabolic lipases and proteases, and numerous transporters to assimilate the resulting nutrients. The results of these efforts will ensure that the Candida research community has uniform and comprehensive genomic information for medical research as well as for future diagnostic and therapeutic applications.

  20. Extracellular enolase of Candida albicans is involved in colonization of mammalian intestinal epithelium

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    Richard Cardoso Silva

    2014-06-01

    Full Text Available Enolase is secreted by C. albicans and is present in its biofilms although its extracellular function is unknown. Here we show that extracellular enolase mediates the colonization of small intestine mucosa by C. albicans. Assays using intestinal mucosa disks show that C. albicans adhesion is inhibited, in a dose dependent mode, either by pretreatment of intestinal epithelium mucosa disks with recombinant C. albicans enolase (70% at 0.5 mg/ml enolase or by pretreatment of C. albicans yeasts with anti-enolase antibodies (48% with 20 µg antiserum. Also using flow cytometry, immunoblots of conditioned media and confocal microscopy we demonstrate that enolase is present in biofilms and that the extracellular enolase is not an artifact due to cell lysis, but must represent functional secretion of a stable form. This is the first direct evidence that C. albicans extracellular enolase mediates colonization on its primary translocation site. Also, because enolase is encoded by a single locus in C. albicans, its dual role peptide, as glycolytic enzyme and extracellular peptide, is a remarkable example of gene sharing in fungi.

  1. Increased Filamentous Growth of Candida albicans in Simulated Microgravity

    Institute of Scientific and Technical Information of China (English)

    Sara D. Altenburg; Sheila M. Nielsen-Preiss; Linda E. Hyman

    2008-01-01

    Knowledge of simulated microgravity (SMG)-induced changes in the pathogenicity of microorganisms is important for success of long-term spaceflight. In a previous study using the high aspect ratio vessel bioreactor, we showed that the yeast species Saccharomyces cerevisiae underwent a significant phenotypic response when grown in modeled microgravity, which was reflected in the analysis of gene expression profiles. In this study, we establish that Candida albicans responds to SMG in a similar fashion, demonstrating that there is a conserved response among yeast to this environmental stress. We also report that the growth of C. albicans in SMG results in a morphogenic switch that is consistent with enhanced pathogenicity. Specifically, we observed an increase in filamentous forms of the organism and accompanying changes in the expression of two genes associated with the yeasthyphal transition. The morphological response may have significant implications for astronauts' safety, as the fungal pathogen may become more virulent during spaceflight.

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

    Science.gov (United States)

    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.

  3. 白念珠菌ERG11基因突变及高表达对耐药的影响%Different sources of drug resistant Candida albicans clinical strains exist over-expression and novel mutation in ERG11 gene

    Institute of Scientific and Technical Information of China (English)

    王一如; 冯文莉; 杨静; 奚志琴; 乔祖莎

    2014-01-01

    目的 探讨白念珠菌ERG11基因突变、高表达及二者的相互作用在氟康唑耐药中的作用.方法 采用PCR法扩增实验菌株的ERG11基因,并进行测序及生物信息学分析,筛查突变位点;抽提实验菌株总RNA,并逆转录合成cDNA,采用实时荧光定量PCR(FQ-RT-PCR)法检测ERG11基因的表达水平.结果 24株临床菌株中,共检测出ERG 11基因存在24个同义突变位点和5个错义突变位点,其中,E174A、T123I、V234F为新发位点;白念珠菌ERG11基因在耐药组中的表达量高于敏感组,差异具有统计学意义未发生错义突变的白念珠菌耐药株ERG11基因的表达量高于发生错义突变的,差异具有统计学意义.结论 白念珠菌ERG 11基因的5个错义突变A114V、E174A、T123I、Y132H、V234F可能与氟康唑耐药形成有关;ERG11基因的高表达可能与氟康唑耐药有关;ERG11基因的错义突变可能对该基因的高表达存在抑制作用.%Objective To explore ERG11 gene mutations,over-expression and the relation between each other of Candida albicans in the role of fluconazole resistance.Methods ERG11 genes of 24 strains Candida albicans isolated from patients were amplified by PCR and bilaterally sequenced.The sequencing result was analyzed by Blast and compared with published sequence (GenBank AY856352) to analyze gene mutations.Then the total RNA was extracted from 24 strains Candida albicans and cDNA was synthesized.The expression of ERG11 gene was detected by fluorescence quantitative RT-PCR.Results 24 silent mutations and 5 missense mutations were identified in 24 strains Candida albicans isolates.Among missense mutations,E174A,T123I and V234F were not found yet in previous studies.Higher expression of ERG11 gene was observed in fluconazoleresistant isolates compared with fluconazole-susceptible isolates [(3.89 ± 2.4) vs.(0.78 ± 0.31)],with statistically significant difference (P < 0.05).Conclusions Drug resistance of Candida albicans to

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

    Science.gov (United States)

    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.

  5. Global Transcriptome Sequencing Identifies Chlamydospore Specific Markers in Candida albicans and Candida dubliniensis

    LENUS (Irish Health Repository)

    Palige, Katja

    2013-04-15

    Candida albicans and Candida dubliniensis are pathogenic fungi that are highly related but differ in virulence and in some phenotypic traits. During in vitro growth on certain nutrient-poor media, C. albicans and C. dubliniensis are the only yeast species which are able to produce chlamydospores, large thick-walled cells of unknown function. Interestingly, only C. dubliniensis forms pseudohyphae with abundant chlamydospores when grown on Staib medium, while C. albicans grows exclusively as a budding yeast. In order to further our understanding of chlamydospore development and assembly, we compared the global transcriptional profile of both species during growth in liquid Staib medium by RNA sequencing. We also included a C. albicans mutant in our study which lacks the morphogenetic transcriptional repressor Nrg1. This strain, which is characterized by its constitutive pseudohyphal growth, specifically produces masses of chlamydospores in Staib medium, similar to C. dubliniensis. This comparative approach identified a set of putatively chlamydospore-related genes. Two of the homologous C. albicans and C. dubliniensis genes (CSP1 and CSP2) which were most strongly upregulated during chlamydospore development were analysed in more detail. By use of the green fluorescent protein as a reporter, the encoded putative cell wall related proteins were found to exclusively localize to C. albicans and C. dubliniensis chlamydospores. Our findings uncover the first chlamydospore specific markers in Candida species and provide novel insights in the complex morphogenetic development of these important fungal pathogens.

  6. Role of Ess1 in growth, morphogenetic switching, and RNA polymerase II transcription in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Dhanushki Samaranayake

    Full Text Available Candida albicans is a fungal pathogen that causes potentially fatal infections among immune-compromised individuals. The emergence of drug resistant C. albicans strains makes it important to identify new antifungal drug targets. Among potential targets are enzymes known as peptidyl-prolyl cis/trans isomerases (PPIases that catalyze isomerization of peptide bonds preceding proline. We are investigating a PPIase called Ess1, which is conserved in all major human pathogenic fungi. Previously, we reported that C. albicans Ess1 is essential for growth and morphogenetic switching. In the present study, we re-evaluated these findings using more rigorous genetic analyses, including the use of additional CaESS1 mutant alleles, distinct marker genes, and the engineering of suitably-matched isogenic control strains. The results confirm that CaEss1 is essential for growth in C. albicans, but show that reduction of CaESS1 gene dosage by half (δ/+ does not interfere with morphogenetic switching. However, further reduction of CaEss1 levels using a conditional allele does reduce morphogenetic switching. We also examine the role of the linker α-helix that distinguishes C. albicans Ess1 from the human Pin1 enzyme, and present results of a genome-wide transcriptome analysis. The latter analysis indicates that CaEss1 has a conserved role in regulation of RNA polymerase II function, and is required for efficient termination of small nucleolar RNAs and repression of cryptic transcription in C. albicans.

  7. Loss of Heterozygosity at an Unlinked Genomic Locus Is Responsible for the Phenotype of a Candida albicans sap4Δ sap5Δ sap6Δ Mutant ▿

    OpenAIRE

    Dunkel, Nico; Morschhäuser, Joachim

    2011-01-01

    The diploid genome of the pathogenic yeast Candida albicans exhibits a high degree of heterozygosity. Genomic alterations that result in a loss of heterozygosity at specific loci may affect phenotypes and confer a selective advantage under certain conditions. Such genomic rearrangements can also occur during the construction of C. albicans mutants and remain undetected. The SAP2 gene on chromosome R encodes a secreted aspartic protease that is induced and required for growth of C. albicans wh...

  8. Espondilodiscitis por Candida albicans Candida albicans spondylodiscitis: Diagnosis and Treatment

    OpenAIRE

    2008-01-01

    Propósito: Describir los hallazgos radiológicos distintivos en resonancia magnética de las espondilodiscitis fúngicas (Candida albicans) y su importancia en el diagnóstico temprano de estas entidades. Se reporta el caso de un paciente masculino de 51 años de edad, inmunocomprometido, que consulta por fiebre y dolor lumbar. La RM con gadolinio demostró en secuencias T2 hipointensidad de la médula ósea en los cuerpos vertebrales afectados, asociados a cambios en la señal discal y realce intenso...

  9. 阴道白假丝酵母菌的耐药性和ERG11基因突变关系研究%Research on the relationship between the mutations of ERG11 gene and the resistance of pyrrolic antifungal agents in vaginal candida albicans

    Institute of Scientific and Technical Information of China (English)

    谭皓妍; 李倩珺; 冯浩华; 何艳屏

    2014-01-01

    目的 探讨ERG11基因突变与白假丝酵母菌对吡咯类药物敏感性下降的关系.方法 收集VVC患者的白假丝酵母菌60株,用科玛嘉念珠菌显色培养基作菌种鉴定,纸片扩散法进行药敏试验,选取所有中度敏感株和耐药株用聚合酶链反应扩增(PCR)ERG11基因,将PCR产物进行测序分析和比对分析.结果 60株白假丝酵母菌对咪康唑、酮康唑和氟康唑敏感率分别为36.7%、56.1%和80%;将38株中度敏感株和耐药株进行ERG11基因分析后共发现29个有义突变和25个同义突变,其中,有义突变中发现多个新突变位点.结论 有些新发现的突变位点可能与耐药相关;多位点有义突变可能降低菌株对药物的敏感性.%Objective To invesigate the relationship between mutation of ERG11 gene and the decreased sensitivity to pyrrolic antifungal agents in vaginal Candida albicans.Methods sixty strains of Candida albicans from VVC patients were collected and identified by CHROM agar.The drug resistance was detected by disk diffusion method.The ERG11 gene of the moderately susceptible and resistant strains was amplified by PCR.The PCR products were analyzed by DNA sequencing.Results The sensitive rates of sixty strains of Candida albicans strains to miconazole,ketoconazole and fluconazole were 36.7%,56.1% and 80%,respectively.After comparison of ERG11 gene DNA sequences alignment,we found 29 missense mutations and 25 silent mutations in 38 strains of moderately susceptible and resistant strains.Several new mutations were found in ERG11 genein the missense mutations.Conclusion Some new mutations were found in ERG11 gene which might be associated with drug resistance.Multiple amino acid substitutions in Erg11 of vaginal Candida albicans may reduce the sensitivity to pyrrolic antifungal agents.

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

    Science.gov (United States)

    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

  11. Mixed biofilms formed by C. albicans and non-albicans species: a study of microbial interactions.

    Science.gov (United States)

    Santos, Jéssica Diane dos; Piva, Elisabete; Vilela, Simone Furgeri Godinho; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos

    2016-01-01

    Most Candida infections are related to microbial biofilms often formed by the association of different species. The objective of this study was to evaluate the interactions between Candida albicans and non-albicans species in biofilms formed in vitro. The non-albicans species studied were:Candida tropicalis, Candida glabrata and Candida krusei. Single and mixed biofilms (formed by clinical isolates of C. albicans and non-albicans species) were developed from standardized suspensions of each strain (10(7) cells/mL), on flat-bottom 96-well microtiter plates for 48 hour. These biofilms were analyzed by counting colony-forming units (CFU/mL) in Candida HiChrome agar and by determining cell viability, using the XTT 2,3-bis (2-methoxy-4-nitro-5-sulphophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide colorimetric assay. The results for both the CFU/mL count and the XTT colorimetric assay showed that all the species studied were capable of forming high levels of in vitro biofilm. The number of CFU/mL and the metabolic activity of C. albicans were reduced in mixed biofilms with non-albicans species, as compared with a single C. albicans biofilm. Among the species tested, C. krusei exerted the highest inhibitory action against C. albicans. In conclusion, C. albicans established antagonistic interactions with non-albicans Candida species in mixed biofilms.

  12. Adaptation of Candida albicans to commensalism in the gut.

    Science.gov (United States)

    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.

  13. ERG11 mutations associated with azole resistance in Candida albicans isolates from vulvovaginal candidosis patients

    Institute of Scientific and Technical Information of China (English)

    Bin; Wang; Li-Hua; Huang; Ji-Xue; Zhao; Man; Wei; Hua; Fang; Dan-Yang; Wang; Hong-Fa; Wang; Ji-Gang; Yin; Mei; Xiang

    2015-01-01

    Objective: To investigate the azole susceptibility of Candida albicans(C.albicans)from vulvovaginal candidosis patients and to analyze the relationship between ERG11 gene mutations in these isolates and azole resistance.Methods: Three hundred and two clinical isolates of Candida species were collected.Azole susceptibility was tested in vitro in microdilution studies. The ERG11 genes of 17 isolates of C. albicans(2 susceptibles, 5 dose-dependent resistants and 10 resistants) were amplified and sequenced.Results: Of the 302 isolates collected, 70.2% were C. albicans, of which 8.5%, 3.8% and4.2% were resistant to fluconazole, itraconazole and voriconazole, respectively. In total,27 missense mutations were detected in ERG11 genes from resistant/susceptible dosedependent isolates. Among them, Y132 H, A114 S, and Y257 H substitutions were most prevalent and were known to cause fluconazole resistance. G464 S and F72 S also have been proved to cause fluconazole resistance. Two novel substitutions(T285A, S457P) in hotspot regions were identified.Conclusions: Twenty seven mutations in the ERG11 gene were identified in azoleresistant C. albicans isolates, which indicated a possible relation with the increase in resistance to azole drugs and the recurrence of vulvovaginal candidosis. The relationship of two novel substitutions(T285A, S457P) with fluconazole resistance needs to be further verified by site-directed mutagenesis.

  14. ERG11 mutations associated with azole resistance in Candida albicans isolates from vulvovaginal candidosis patients

    Institute of Scientific and Technical Information of China (English)

    Bin Wang; Li-Hua Huang; Ji-Xue Zhao; Man Wei; Hua Fang; Dan-Yang Wang; Hong-Fa Wang; Ji-Gang Yin; Mei Xiang

    2015-01-01

    Objective:To investigate the azole susceptibility of Candida albicans (C. albicans) from vulvovaginal candidosis patients and to analyze the relationship between ERG11 gene mutations in these isolates and azole resistance. Methods:Three hundred and two clinical isolates of Candida species were collected. Azole susceptibility was tested in vitro in microdilution studies. The ERG11 genes of 17 isolates of C. albicans (2 susceptibles, 5 dose-dependent resistants and 10 resistants) were amplified and sequenced. Results:Of the 302 isolates collected, 70.2%were C. albicans, of which 8.5%, 3.8%and 4.2%were resistant to fluconazole, itraconazole and voriconazole, respectively. In total, 27 missense mutations were detected in ERG11 genes from resistant/susceptible dose-dependent isolates. Among them, Y132H, A114S, and Y257H substitutions were most prevalent and were known to cause fluconazole resistance. G464S and F72S also has been proved to cause fluconazole resistance. Two novel substitutions (T285A, S457P) in hotspot regions were identified. Conclusions:Twenty seven mutations in the ERG11 gene were identified in azole-resistant C. albicans isolates, which indicated a possible relation with the increase in resistance to azole drugs and the recurrence of vulvovaginal candidosis. The relationship of two novel substitutions (T285A, S457P) with fluconazole resistance needs to be further verified by site-directed mutagenesis.

  15. Candida albicans escapes from mouse neutrophils

    DEFF Research Database (Denmark)

    Ermert, David; Niemiec, Maria J; Röhm, Marc

    2013-01-01

    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...

  16. Dynamics of Agglutinin-Like Sequence (ALS) Protein Localization on the Surface of Candida Albicans

    Science.gov (United States)

    Coleman, David Andrew

    2009-01-01

    The ALS gene family encodes large cell-surface glycoproteins associated with "C. albicans" pathogenesis. Als proteins are thought to act as adhesin molecules binding to host tissues. Wide variation in expression levels among the ALS genes exists and is related to cell morphology and environmental conditions. "ALS1," "ALS3," and "ALS4" are three of…

  17. Expression of Candida Albicans Secreted Aspartyl Proteinase in Acute Vaginal Candidiasis

    Institute of Scientific and Technical Information of China (English)

    LIN Nengxing; FENG Jing; TU Yating; FENG Aiping

    2007-01-01

    In order to analyze the in vivo expression of Candida albicans secreted aspartyl proteinases (SAP) in human vaginal infection, the vaginal secretion from 29 human subjects was collected by vaginal swab, and the expression of SAP1-SAP6 was detected by reverse-transcriptase polymerase chain reaction using specific primer sets. It was found that Sap2 and Sap5 were the most common genes expressed during infection; Sap3 and Sap4 were detected in all subjects and all 6 SAP genes were simultaneously expressed in some patients with vaginal candidiasis. It was suggested that the SAP family is expressed by Candida albicans during infection in human and that Candida albicans infection is associated with the differential expression of individual SAP genes which may be involved in the pathogenesis of vaginal candidiasis.

  18. Espondilodiscitis por Candida albicans Candida albicans spondylodiscitis: Diagnosis and Treatment

    Directory of Open Access Journals (Sweden)

    Silvina De Luca

    2008-03-01

    Full Text Available Propósito: Describir los hallazgos radiológicos distintivos en resonancia magnética de las espondilodiscitis fúngicas (Candida albicans y su importancia en el diagnóstico temprano de estas entidades. Se reporta el caso de un paciente masculino de 51 años de edad, inmunocomprometido, que consulta por fiebre y dolor lumbar. La RM con gadolinio demostró en secuencias T2 hipointensidad de la médula ósea en los cuerpos vertebrales afectados, asociados a cambios en la señal discal y realce intenso discovertebral. Ante un paciente inmunocomprometido con dolor lumbar que presenta modificaciones disco vertebrales atípicas en la resonancia magnética, debe considerarse la infección micótica dentro de las posibilidades diagnósticas. El diagnóstico de certeza requiere la toma de biopsia del tejido afectado mediante punción aspiración y posterior análisis microbiológico. El tratamiento médico es el de elección, aunque en algunos casos se plantea el drenaje quirúrgico. El reconocimiento de las características radiológicas distintivas evita retardos en el diagnóstico y el tratamiento.Purpose: To describe Candida albicans spondylodiscitis distinctive imaging findings and treatment. The authors reported a 51 years old, male inmunocompromised patient with fever and lumbar pain. MR findings include bone marrow hypointense signal intensity in T2 weighted of affected vertebral bodies and intense discovertebral enhancement. Candida albicans spondylodiscitis should be considered as one of the differential diagnosis of an inmunocompromised patient with lumbar pain and lumbar atypical findings at MR. Biopsy sample is required in order to reach final diagnosis. The first choice treatment is antyfungal drugs although in certain cases surgery is required. Rapid recognition of distinctive imaging findings avoid missdiagnosis and treatment delays.

  19. Anaerobic bacteria grow within Candida albicans biofilms and induce biofilm formation in suspension cultures.

    Science.gov (United States)

    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.

  20. Mechanisms of the antifungal action of marine metagenome-derived peptide, MMGP1, against Candida albicans.

    Directory of Open Access Journals (Sweden)

    Muthuirulan Pushpanathan

    Full Text Available BACKGROUND: Development of resistant variants to existing antifungal drugs continues to be the serious problem in Candida albicans-induced fungal pathogenesis, which has a considerable impact on animal and human health. Identification and characterization of newer drugs against C. albicans is, therefore, essential. MMGP1 is a direct cell-penetrating peptide recently identified from marine metagenome, which was found to possess potent antifungal activity against C. albicans. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we investigated the mechanism of antifungal action of MMGP1 against C. albicans. Agarose gel shift assay found the peptide to be having a remarkable DNA-binding ability. The modification of the absorption spectra and fluorescence quenching of the tryptophyl residue correspond to the stacking between indole ring and nucleotide bases. The formation of peptide-DNA complexes was confirmed by fluorescence quenching of SYTO 9 probe. The interaction of peptide with plasmid DNA afforded protection of DNA from enzymatic degradation by DNase I. In vitro transcription of mouse β-actin gene in the presence of peptide led to a decrease in the level of mRNA synthesis. The C. albicans treated with MMGP1 showed strong inhibition of biosynthetic incorporation of uridine analog 5-ethynyluridine (EU into nascent RNA, suggesting the peptide's role in the inhibition of macromolecular synthesis. Furthermore, the peptide also induces endogenous accumulation of reactive oxygen species (ROS in C. albicans. MMGP1 supplemented with glutathione showed an increased viability of C. albicans cells. The hyper-produced ROS by MMGP1 leads to increased levels of protein carbonyls and thiobarbituric acid reactive substances and it also causes dissipation of mitochondrial membrane potential and DNA fragmentation in C. albicans cells. CONCLUSION: And Significance: Therefore, the antifungal activity of MMGP1 could be attributed to its binding with DNA, causing

  1. Property differences among the four major Candida albicans strain clades.

    Science.gov (United States)

    MacCallum, Donna M; Castillo, Luis; Nather, Kerstin; Munro, Carol A; Brown, Alistair J P; Gow, Neil A R; Odds, Frank C

    2009-03-01

    A selection of 43 Candida albicans isolates, chosen to represent the four major strain clades of the species and also intraclade diversity, was screened for their virulence in the murine intravenous challenge model of C. albicans infection, for a range of properties measurable in vitro that might relate to virulence, and for the numbers of midrepeat sequences in genes of the ALS and HYR families. Heterozygosity at the mating type locus and low whole-cell acid phosphatase activity and growth rate at 40 degrees C were found to be significantly positively associated with the most virulent isolates. Acid phosphatase activity and growth in 2 M NaCl were statistically significant variables between clades by univariate analysis. Isolates in different clades also differed significantly in midrepeat sequence alleles of ALS2, ALS4, ALS6, ALS7, ALS9, HYR1, and HYR2. There was no association between the midrepeat alleles of any ALS or HYR gene and the virulence of isolates to mice. Genome-wide transcript profiles of 20 isolates (5 per clade) grown under two conditions showed considerable variation between individual isolates, but only a small number of genes showed statistically significant differential gene expression between clades. Analysis of the expression profiles by overall strain virulence revealed 18 open reading frames differing significantly between isolates of high, intermediate, and low virulence. Four of these genes encoded functions related to phosphate uptake and metabolism. This finding and the significant association between whole-cell acid phosphatase activity and virulence led us to disrupt PHO100, which encodes a predicted periplasmic acid phosphatase. The pho100Delta mutant was mildly but significantly attenuated in terms of survival curves in the mouse model. The study has extended the range of properties known to differ between C. albicans clades and suggests a possible but minor role of phosphate metabolism in the virulence of the species.

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

    Science.gov (United States)

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

    2014-09-01

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

  3. Capric acid secreted by S. boulardii inhibits C. albicans filamentous growth, adhesion and biofilm formation.

    Directory of Open Access Journals (Sweden)

    Anna Murzyn

    Full Text Available Candidiasis are life-threatening systemic fungal diseases, especially of gastro intestinal track, skin and mucous membranes lining various body cavities like the nostrils, the mouth, the lips, the eyelids, the ears or the genital area. Due to increasing resistance of candidiasis to existing drugs, it is very important to look for new strategies helping the treatment of such fungal diseases. One promising strategy is the use of the probiotic microorganisms, which when administered in adequate amounts confer a health benefit. Such a probiotic microorganism is yeast Saccharomyces boulardii, a close relative of baker yeast. Saccharomyces boulardii cells and their extract affect the virulence factors of the important human fungal pathogen C. albicans, its hyphae formation, adhesion and biofilm development. Extract prepared from S. boulardii culture filtrate was fractionated and GC-MS analysis showed that the active fraction contained, apart from 2-phenylethanol, caproic, caprylic and capric acid whose presence was confirmed by ESI-MS analysis. Biological activity was tested on C. albicans using extract and pure identified compounds. Our study demonstrated that this probiotic yeast secretes into the medium active compounds reducing candidal virulence factors. The chief compound inhibiting filamentous C. albicans growth comparably to S. boulardii extract was capric acid, which is thus responsible for inhibition of hyphae formation. It also reduced candidal adhesion and biofilm formation, though three times less than the extract, which thus contains other factors suppressing C. albicans adherence. The expression profile of selected genes associated with C. albicans virulence by real-time PCR showed a reduced expression of HWP1, INO1 and CSH1 genes in C. albicans cells treated with capric acid and S. boulardii extract. Hence capric acid secreted by S. boulardii is responsible for inhibition of C. albicans filamentation and partially also adhesion and

  4. Honokiol induces reactive oxygen species-mediated apoptosis in Candida albicans through mitochondrial dysfunction

    Science.gov (United States)

    Sun, Lingmei; Liao, Kai; Hang, Chengcheng; Wang, Dayong

    2017-01-01

    Objective To investigate the effects of honokiol on induction of reactive oxygen species (ROS), antioxidant defense systems, mitochondrial dysfunction, and apoptosis in Candida albicans. Methods To measure ROS accumulation, 2′,7′-dichlorofluorescein diacetate fluorescence was used. Lipid peroxidation was assessed using both fluorescence staining and a thiobarbituric acid reactive substances (TBARS) assay. Protein oxidation was determined using dinitrophenylhydrazine derivatization. Antioxidant enzymatic activities were measured using commercially available detection kits. Superoxide dismutase (SOD) genes expression was measured using real time RT-PCR. To assess its antifungal abilities and effectiveness on ROS accumulation, honokiol and the SOD inhibitor N,N′-diethyldithiocarbamate (DDC) were used simultaneously. Mitochondrial dysfunction was assessed by measuring the mitochondrial membrane potential (mtΔψ). Honokiol-induced apoptosis was assessed using an Annexin V-FITC apoptosis detection kit. Results ROS, lipid peroxidation, and protein oxidation occurred in a dose-dependent manner in C. albicans after honokiol treatment. Honokiol caused an increase in antioxidant enzymatic activity. In addition, honokiol treatment induced SOD genes expression in C. albicans cells. Moreover, addition of DDC resulted in increased endogenous ROS levels and potentiated the antifungal activity of honokiol. Mitochondrial dysfunction was confirmed by measured changes to mtΔψ. The level of apoptosis increased in a dose-dependent manner after honokiol treatment. Conclusions Collectively, these results indicate that honokiol acts as a pro-oxidant in C. albicans. Furthermore, the SOD inhibitor DDC can be used to potentiate the activity of honokiol against C. albicans. PMID:28192489

  5. Thiazolidinedione-8 alters symbiotic relationship in C. albicans-S. mutans dual species biofilm

    Directory of Open Access Journals (Sweden)

    Mark eFeldman

    2016-02-01

    Full Text Available The small molecule, thiazolidinedione-8 (S-8 was shown to impair biofilm formation of various microbial pathogens, including the fungus Candida albicans and Streptococcus mutans. Previously, we have evaluated the specific molecular mode of S-8 action against C. albicans biofilm-associated pathogenicity. In this study we investigated the influence of S-8 on dual species, C. albicans-S. mutans biofilm. We show that in the presence of S-8 a reduction of the co-species biofilm formation occurred with a major effect on C. albicans. Biofilm biomass and exopolysaccharide (EPS production were significantly reduced by S-8. Moreover, the agent caused oxidative stress associated with a strong induction of reactive oxygen species (ROS and hydrogen peroxide uptake inhibition by a mixed biofilm. In addition, S-8 altered symbiotic relationship between these species by a complex mechanism. Streptococcal genes associated with quorum sensing (comDE and luxS, EPS production (gtfBCD and gbpB, as well as genes related to protection against oxidative stress (nox and sodA were markedly upregulated by S-8. In contrast, fungal genes related to hyphae formation (hwp1, adhesion (als3, hydrophobicity (csh1 and oxidative stress response (sod1, sod2 and cat1 were downregulated in the presence of S-8. In addition, ywp1 gene associated with yeast form of C. albicans was induced by S-8, which is correlated with appearance of mostly yeast cells in S-8 treated dual species biofilms. We concluded that S-8 disturbs symbiotic balance between C. albicans and S. mutans in dual species biofilm.

  6. Thiazolidinedione-8 Alters Symbiotic Relationship in C. albicans-S. mutans Dual Species Biofilm.

    Science.gov (United States)

    Feldman, Mark; Ginsburg, Isaac; Al-Quntar, Abed; Steinberg, Doron

    2016-01-01

    The small molecule, thiazolidinedione-8 (S-8) was shown to impair biofilm formation of various microbial pathogens, including the fungus Candida albicans and Streptococcus mutans. Previously, we have evaluated the specific molecular mode of S-8 action against C. albicans biofilm-associated pathogenicity. In this study we investigated the influence of S-8 on dual species, C. albicans-S. mutans biofilm. We show that in the presence of S-8 a reduction of the co-species biofilm formation occurred with a major effect on C. albicans. Biofilm biomass and exopolysaccharide (EPS) production were significantly reduced by S-8. Moreover, the agent caused oxidative stress associated with a strong induction of reactive oxygen species and hydrogen peroxide uptake inhibition by a mixed biofilm. In addition, S-8 altered symbiotic relationship between these species by a complex mechanism. Streptococcal genes associated with quorum sensing (QS) (comDE and luxS), EPS production (gtfBCD and gbpB), as well as genes related to protection against oxidative stress (nox and sodA) were markedly upregulated by S-8. In contrast, fungal genes related to hyphae formation (hwp1), adhesion (als3), hydrophobicity (csh1), and oxidative stress response (sod1, sod2, and cat1) were downregulated in the presence of S-8. In addition, ywp1 gene associated with yeast form of C. albicans was induced by S-8, which is correlated with appearance of mostly yeast cells in S-8 treated dual species biofilms. We concluded that S-8 disturbs symbiotic balance between C. albicans and S. mutans in dual species biofilm.

  7. Adaptive immune responses to Candida albicans infection.

    Science.gov (United States)

    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.

  8. In vitro modification of Candida albicans invasiveness.

    Science.gov (United States)

    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.

  9. Triclosan antagonises fluconazole activity against Candida albicans

    OpenAIRE

    2012-01-01

    Epub October 4th Triclosan is a broad-spectrum antimicrobial compound commonly used in oral hygiene products. Investigation of its activity against Candida albicans showed that triclosan was fungicidal at concentrations of 16 mg/L. However, at subinhibitory concentrations (0.5-2 mg/L) triclosan antagonized the activity of fluconazole. Although triclosan induced CDR1 expression in C. albicans, antagonism was still observed in cdr1? and cdr2? strains. Triclosan did not affect fluconazole upt...

  10. Candida albicans escapes from mouse neutrophils.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 albicans Candida strains. The increased IL-1β concentration may be one of the host response components associated with non-albicans Candida infection.

  13. Improved detection of Candida albicans by PCR in blood of neutropenic mice with systemic candidiasis

    NARCIS (Netherlands)

    A.J.M. Munting-van Deventer; W.H.F. Goessens (Wil); A.F. van Belkum (Alex); H.J. van Vliet; E.W.M. van Etten (Els); H.A. Verbrugh (Henri)

    1995-01-01

    textabstractA PCR using primers aimed at the multicopy gene coding for the small subunit rRNA and resulting in the synthesis of a 180-bp fragment was evaluated for its use in diagnosing invasive candidiasis in comparison with blood culture. With the use of a C. albicans

  14. Contribution of Candida albicans ALS1 to the Pathogenesis of Experimental Oropharyngeal Candidiasis

    OpenAIRE

    2002-01-01

    We investigated the contribution of Candida albicans ALS1, which encodes a candidal adhesin, to the pathogenesis of experimental murine oropharyngeal candidiasis. Our results indicate that the ALS1 gene product is important for the adherence of the organism to the oral mucosa during the early stage of the infection.

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

    Science.gov (United States)

    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.

  16. Control of the C. albicans cell wall damage response by transcriptional regulator Cas5.

    Directory of Open Access Journals (Sweden)

    Vincent M Bruno

    2006-03-01

    Full Text Available The fungal cell wall is vital for growth, development, and interaction of cells with their environment. The response to cell wall damage is well understood from studies in the budding yeast Saccharomyces cerevisiae, where numerous cell wall integrity (CWI genes are activated by transcription factor ScRlm1. Prior evidence suggests the hypothesis that both response and regulation may be conserved in the major fungal pathogen Candida albicans. We have tested this hypothesis by using a new C. albicans genetic resource: we have screened mutants defective in putative transcription factor genes for sensitivity to the cell wall biosynthesis inhibitor caspofungin. We find that the zinc finger protein CaCas5, which lacks a unique ortholog in S. cerevisiae, governs expression of many CWI genes. CaRlm1 has a modest role in this response. The transcriptional coactivator CaAda2 is also required for expression of many CaCas5-dependent genes, as expected if CaCas5 recruits CaAda2 to activate target gene transcription. Many caspofungin-induced C. albicans genes specify endoplasmic reticulum and secretion functions. Such genes are not induced in S. cerevisiae, but promote its growth in caspofungin. We have used a new resource to identify a key C. albicans transcriptional regulator of CWI genes and antifungal sensitivity. Our gene expression findings indicate that both divergent and conserved response genes may have significant functional roles. Our strategy may be broadly useful for identification of pathogen-specific regulatory pathways and critical response genes.

  17. Potent Activities of Roemerine against Candida albicans and the Underlying Mechanisms.

    Science.gov (United States)

    Ma, Chaoyu; Du, Faya; Yan, Lan; He, Gonghao; He, Jianchang; Wang, Chengying; Rao, Gaoxiong; Jiang, Yuanying; Xu, Guili

    2015-01-01

    Roemerine (RM) is an aporphine alkaloid isolated from the fresh rattan stem of Fibraurea recisa, and it has been demonstrated to have certain antifungal activity. This study aimed to investigate the antifungal activity of RM and the underlying mechanisms in Candida albicans (C. albicans). The in vitro antifungal activity of RM was evaluated by a series of experiments, including the XTT reduction assay, confocal laser scanning microscopy assay, scanning electron microscope assay. Results showed that 1 μg/mL RM inhibited biofilm formation significantly (p albicans in a dose-dependent manner. The biofilm-specific and hypha-specific genes such as YWP1, SAP5, SAP6, HWP1, ECE1 were up-regulated and EFG1 was down-regulated after 8 μg/mL RM treatment. Furthermore, the toxicity of RM was investigated using C. elegans worms, three cancer cells and one normal cell. The date showed that RM had no significant toxicity. In conclusion, RM could inhibited the formation of C. albicans biofilm in vitro, but it had no fungicidal effect on planktonic C. albicans cells, and the anti-biofilm mechanism may be related to the cAMP pathway.

  18. Potent Activities of Roemerine against Candida albicans and the Underlying Mechanisms

    Directory of Open Access Journals (Sweden)

    Chaoyu Ma

    2015-09-01

    Full Text Available Roemerine (RM is an aporphine alkaloid isolated from the fresh rattan stem of Fibraurea recisa, and it has been demonstrated to have certain antifungal activity. This study aimed to investigate the antifungal activity of RM and the underlying mechanisms in Candida albicans (C. albicans. The in vitro antifungal activity of RM was evaluated by a series of experiments, including the XTT reduction assay, confocal laser scanning microscopy assay, scanning electron microscope assay. Results showed that 1 μg/mL RM inhibited biofilm formation significantly (p < 0.01 both in Spider medium and Lee’s medium. In addition, RM could inhibit yeast-to-hyphae transition of C. albicans in a dose-dependent manner. The biofilm-specific and hypha-specific genes such as YWP1, SAP5, SAP6, HWP1, ECE1 were up-regulated and EFG1 was down-regulated after 8 μg/mL RM treatment. Furthermore, the toxicity of RM was investigated using C. elegans worms, three cancer cells and one normal cell. The date showed that RM had no significant toxicity. In conclusion, RM could inhibited the formation of C. albicans biofilm in vitro, but it had no fungicidal effect on planktonic C. albicans cells, and the anti-biofilm mechanism may be related to the cAMP pathway.

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

    Science.gov (United States)

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

    2016-03-31

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

  20. Genetic control of conventional and pheromone-stimulated biofilm formation in Candida albicans.

    Science.gov (United States)

    Lin, Ching-Hsuan; Kabrawala, Shail; Fox, Emily P; Nobile, Clarissa J; Johnson, Alexander D; Bennett, Richard J

    2013-01-01

    Candida albicans can stochastically switch between two phenotypes, white and opaque. Opaque cells are the sexually competent form of C. albicans and therefore undergo efficient polarized growth and mating in the presence of pheromone. In contrast, white cells cannot mate, but are induced - under a specialized set of conditions - to form biofilms in response to pheromone. In this work, we compare the genetic regulation of such "pheromone-stimulated" biofilms with that of "conventional" C. albicans biofilms. In particular, we examined a network of six transcriptional regulators (Bcr1, Brg1, Efg1, Tec1, Ndt80, and Rob1) that mediate conventional biofilm formation for their potential roles in pheromone-stimulated biofilm formation. We show that four of the six transcription factors (Bcr1, Brg1, Rob1, and Tec1) promote formation of both conventional and pheromone-stimulated biofilms, indicating they play general roles in cell cohesion and biofilm development. In addition, we identify the master transcriptional regulator of pheromone-stimulated biofilms as C. albicans Cph1, ortholog of Saccharomyces cerevisiae Ste12. Cph1 regulates mating in C. albicans opaque cells, and here we show that Cph1 is also essential for pheromone-stimulated biofilm formation in white cells. In contrast, Cph1 is dispensable for the formation of conventional biofilms. The regulation of pheromone- stimulated biofilm formation was further investigated by transcriptional profiling and genetic analyses. These studies identified 196 genes that are induced by pheromone signaling during biofilm formation. One of these genes, HGC1, is shown to be required for both conventional and pheromone-stimulated biofilm formation. Taken together, these observations compare and contrast the regulation of conventional and pheromone-stimulated biofilm formation in C. albicans, and demonstrate that Cph1 is required for the latter, but not the former.

  1. The role of Candida albicans homologous recombination factors Rad54 and Rdh54 in DNA damage sensitivity

    Directory of Open Access Journals (Sweden)

    White Theodore C

    2011-09-01

    Full Text Available Abstract Background The fungal pathogen Candida albicans is frequently seen in immune suppressed patients, and resistance to one of the most widely used antifungals, fluconazole (FLC, can evolve rapidly. In recent years it has become clear that plasticity of the Candida albicans genome contributes to drug resistance through loss of heterozygosity (LOH at resistance genes and gross chromosomal rearrangements that amplify gene copy number of resistance associated genes. This study addresses the role of the homologous recombination factors Rad54 and Rdh54 in cell growth, DNA damage and FLC resistance in Candida albicans. Results The data presented here support a role for homologous recombination in cell growth and DNA damage sensitivity, as Candida albicans rad54Δ/rad54Δ mutants were hypersensitive to MMS and menadione, and had an aberrant cell and nuclear morphology. The Candida albicans rad54Δ/rad54Δ mutant was defective in invasion of Spider agar, presumably due to the altered cellular morphology. In contrast, mutation of the related gene RDH54 did not contribute significantly to DNA damage resistance and cell growth, and deletion of either Candida albicans RAD54 or Candida albicans RDH54 did not alter FLC susceptibility. Conclusions Together, these results support a role for homologous recombination in genome stability under nondamaging conditions. The nuclear morphology defects in the rad54Δ/rad54Δ mutants show that Rad54 performs an essential role during mitotic growth and that in its absence, cells arrest in G2. The viability of the single mutant rad54Δ/rad54Δ and the inability to construct the double mutant rad54Δ/rad54Δ rdh54Δ/rdh54Δ suggests that Rdh54 can partially compensate for Rad54 during mitotic growth.

  2. The parasexual lifestyle of Candida albicans.

    Science.gov (United States)

    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.

  3. The Absence of N-Acetyl-D-glucosamine Causes Attenuation of Virulence of Candida albicans upon Interaction with Vaginal Epithelial Cells In Vitro.

    Science.gov (United States)

    Manczinger, Máté; Bocsik, Alexandra; Kocsis, Gabriella F; Vörös, Andrea; Hegedűs, Zoltán; Ördögh, Lilla; Kondorosi, Éva; Marton, Annamária; Vízler, Csaba; Tubak, Vilmos; Deli, Mária; Kemény, Lajos; Nagy, István; Lakatos, Lóránt

    2015-01-01

    To better understand the molecular events underlying vulvovaginal candidiasis, we established an in vitro system. Immortalized vaginal epithelial cells were infected with live, yeast form C. albicans and C. albicans cultured in the same medium without vaginal epithelial cells were used as control. In both cases a yeast to hyphae transition was robustly induced. Whole transcriptome sequencing was used to identify specific gene expression changes in C. albicans. Numerous genes leading to a yeast to hyphae transition and hyphae specific genes were upregulated in the control hyphae and the hyphae in response to vaginal epithelial cells. Strikingly, the GlcNAc pathway was exclusively triggered by vaginal epithelial cells. Functional analysis in our in vitro system revealed that the GlcNAc biosynthesis is involved in the adherence to, and the ability to kill, vaginal epithelial cells in vitro, thus indicating the key role for this pathway in the virulence of C. albicans upon vulvovaginal candidiasis.

  4. The Absence of N-Acetyl-D-glucosamine Causes Attenuation of Virulence of Candida albicans upon Interaction with Vaginal Epithelial Cells In Vitro

    Directory of Open Access Journals (Sweden)

    Máté Manczinger

    2015-01-01

    Full Text Available To better understand the molecular events underlying vulvovaginal candidiasis, we established an in vitro system. Immortalized vaginal epithelial cells were infected with live, yeast form C. albicans and C. albicans cultured in the same medium without vaginal epithelial cells were used as control. In both cases a yeast to hyphae transition was robustly induced. Whole transcriptome sequencing was used to identify specific gene expression changes in C. albicans. Numerous genes leading to a yeast to hyphae transition and hyphae specific genes were upregulated in the control hyphae and the hyphae in response to vaginal epithelial cells. Strikingly, the GlcNAc pathway was exclusively triggered by vaginal epithelial cells. Functional analysis in our in vitro system revealed that the GlcNAc biosynthesis is involved in the adherence to, and the ability to kill, vaginal epithelial cells in vitro, thus indicating the key role for this pathway in the virulence of C. albicans upon vulvovaginal candidiasis.

  5. The plant defensin RsAFP2 induces cell wall stress, septin mislocalization and accumulation of ceramides in Candida albicans

    Science.gov (United States)

    Thevissen, Karin; de Mello Tavares, Patricia; Xu, Deming; Blankenship, Jill; Vandenbosch, Davy; Idkowiak-Baldys, Jolanta; Govaert, Gilmer; Bink, Anna; Rozental, Sonia; de Groot, Piet W.J.; Davis, Talya R.; Kumamoto, Carol A.; Vargas, Gabriele; Nimrichter, Leonardo; Coenye, Tom; Mitchell, Aaron; Roemer, Terry; Hannun, Yusuf A.; Cammue, Bruno P.A.

    2012-01-01

    Summary The antifungal plant defensin RsAFP2 isolated from radish interacts with fungal glucosylceramides and induces apoptosis in Candida albicans. To further unravel the mechanism of RsAFP2 antifungal action and tolerance mechanisms, we screened a library of 2,868 heterozygous C. albicans deletion mutants and identified 30 RsAFP2-hypersensitive mutants. The most prominent group of RsAFP2 tolerance genes was involved in cell wall integrity and hyphal growth/septin ring formation. Consistent with these genetic data, we demonstrated that RsAFP2 interacts with the cell wall of C. albicans, which also contains glucosylceramides, and activates the cell wall integrity pathway. Moreover, we found that RsAFP2 induces mislocalization of septins and blocks the yeast-to-hypha transition in C. albicans. Increased ceramide levels have previously been shown to result in apoptosis and septin mislocalization. Therefore, ceramide levels in C. albicans membranes were analyzed following RsAFP2 treatment and, as expected, increased accumulation of phytoC24-ceramides in membranes of RsAFP2-treated C. albicans cells was detected. This is the first report on the interaction of a plant defensin with glucosylceramides in the fungal cell wall, causing cell wall stress, and on the effects of a defensin on septin localization and ceramide accumulation. PMID:22384976

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

    Science.gov (United States)

    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.

  7. Candida albicans phospholipomannan triggers inflammatory responses of human keratinocytes through Toll-like receptor 2.

    Science.gov (United States)

    Li, Min; Chen, Qing; Shen, Yongnian; Liu, Weida

    2009-07-01

    The Toll-like receptors (TLRs) play an important role in the recognition of Candida albicans components and activation of innate immunity. Phospholipomannan (PLM), a glycolipid, is expressed at the surface of C. albicans cell wall, which acts as a member of the pathogen-associated molecular patterns family. In this study, we sought to clarify whether C. albicans-native PLM could induce an inflammation response in human keratinocytes and to determine the underlying mechanisms. Exposure of cultured human primary keratinocytes to PLM led to the increased gene expression and secretion of proinflammatory cytokines (IL-6) and chemokines (IL-8). PLM hydrolysed with beta-d-mannoside mannohydrolase failed to induce gene expression and secretion of IL-6 and IL-8. PLM up-regulated the mRNA and protein levels of TLR2, whereas the mRNA level of TLR4 was not altered. Keratinocytes challenged with PLM resulted in the activation of NF-kappaB and mitogen-activated protein kinase (MAPKs) including p38. Anti-TLR2 neutralizing antibody, NFkappaB and p38MAPK inhibitors blocked the PLM-induced secretion of IL-6, IL-8 in keratinocytes, but no such effect was observed in pretreatment with anti-TLR4-neutralizing antibody and lipopolysaccharide inhibitor (polymyxin B). These data suggest C. albicans-native PLM may contribute to the inflammatory responses of cutaneous candidiasis in the TLR2-NF-kappaB and p38MAPK signalling pathway dependent manner.

  8. Candida albicans mannoprotein influences the biological function of dendritic cells.

    Science.gov (United States)

    Pietrella, Donatella; Bistoni, Giovanni; Corbucci, Cristina; Perito, Stefano; Vecchiarelli, Anna

    2006-04-01

    Cell wall components of fungi involved in induction of host immune response are predominantly proteins and glycoproteins, the latter being mainly mannoproteins (MP). In this study we analyse the interaction of the MP from Candida albicans (MP65) with dendritic cells (DC) and demonstrate that MP65 stimulates DC and induces the release of TNF-alpha, IL-6 and the activation of IL-12 gene, with maximal value 6 h post treatment. MP65 induces DC maturation by increasing costimulatory molecules and decreasing CD14 and FcgammaR molecule expression. The latter effect is partly mediated by toll-like receptor 2 (TLR2) and TLR4, and the MyD88-dependent pathway is involved in the process. MP65 enables DC to activate T cell response, its protein core is essential for induction of T cell activation, while its glycosylated portion primarily promotes cytokine production. The mechanisms involved in induction of protective response against C. albicans could be mediated by the MP65 antigen, suggesting that MP65 may be a suitable candidate vaccine.

  9. Candida albicans adhesion to composite resin materials.

    Science.gov (United States)

    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.

  10. Single-strand conformation polymorphism of microsatellite for rapid strain typing of Candida albicans.

    Science.gov (United States)

    Li, Juan; Bai, Feng-Yan

    2007-11-01

    Single-strand conformation polymorphisms (SSCP) of Candida albicans' microsatellite CAI were characterized. Among the 76 clinical isolates recovered from different patients (independent strains), 60 distinct CAI SSCP patterns were recognized, resulting in a discriminatory power of 0.993. The multiple isolates recovered sequentially from the same or different body locations of the same patient showed exactly the same CAI SSCP pattern. The reliability of the SSCP analysis was confirmed by GeneScan and sequence analyses. From the same set of independent strains, 59 distinct CAI genotypes were identified by GeneScan analysis. Sequence comparison showed the advantage of SSCP over GeneSan analysis in the detection of point mutations in the microsatellite. The results indicated that PCR SSCP analysis of CAI microsatellite is a powerful and economical approach for rapid strain typing of C. albicans in clinical laboratories, especially in the detection of microevolutionary changes in microsatellites and in large-scale epidemiological investigation.

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

    Directory of Open Access Journals (Sweden)

    Mikko T Nieminen

    Full Text Available 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 (p40 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 infections.

  12. High Virulence and Antifungal Resistance in Clinical Strains of Candida albicans

    Science.gov (United States)

    Monroy-Pérez, Eric; Paniagua-Contreras, Gloria Luz; Rodríguez-Purata, Pamela; Vaca-Paniagua, Felipe; Vázquez-Villaseñor, Marco; Díaz-Velásquez, Clara; Uribe-García, Alina

    2016-01-01

    Antifungal resistance and virulence properties of Candida albicans are a growing health problem worldwide. To study the expression of virulence and azole resistance genes in 39 clinical strains of C. albicans, we used a model of infection of human vaginal epithelial cells with C. albicans strains isolated from Mexican women with vulvovaginal candidiasis (VVC). The strains were identified by PCR amplification of the ITS1 and ITS2 regions of rRNA. The detection and expression of virulence genes and azole resistance genes MDR1 and CDR1 were performed using PCR and RT-PCR, respectively. All strains were sensitive to nystatin and 38 (97.4%) and 37 (94.9%) were resistant to ketoconazole and fluconazole, respectively. ALS1, SAP4–SAP6, LIP1, LIP2, LIP4, LIP6, LIP7, LIP9, LIP10, and PLB1-PLB2 were present in all strains; SAP1 was identified in 37 (94.8%) isolates, HWP1 in 35 (89.7%), ALS3 in 14 (35.8%), and CDR1 in 26 (66.6%). In nearly all of the strains, ALS1, HWP1, SAP4–SAP6, LIP1–LIP10, PLB1, and PLB2 were expressed, whereas CDR1 was expressed in 20 (51.3%) and ALS3 in 14 (35.8%). In our in vitro model of infection with C. albicans, the clinical strains showed different expression profiles of virulence genes in association with the azole resistance gene CDR1. The results indicate that the strains that infect Mexican patients suffering from VVC are highly virulent and virtually all are insensitive to azoles. PMID:28058052

  13. High Virulence and Antifungal Resistance in Clinical Strains of Candida albicans

    Directory of Open Access Journals (Sweden)

    Eric Monroy-Pérez

    2016-01-01

    Full Text Available Antifungal resistance and virulence properties of Candida albicans are a growing health problem worldwide. To study the expression of virulence and azole resistance genes in 39 clinical strains of C. albicans, we used a model of infection of human vaginal epithelial cells with C. albicans strains isolated from Mexican women with vulvovaginal candidiasis (VVC. The strains were identified by PCR amplification of the ITS1 and ITS2 regions of rRNA. The detection and expression of virulence genes and azole resistance genes MDR1 and CDR1 were performed using PCR and RT-PCR, respectively. All strains were sensitive to nystatin and 38 (97.4% and 37 (94.9% were resistant to ketoconazole and fluconazole, respectively. ALS1, SAP4–SAP6, LIP1, LIP2, LIP4, LIP6, LIP7, LIP9, LIP10, and PLB1-PLB2 were present in all strains; SAP1 was identified in 37 (94.8% isolates, HWP1 in 35 (89.7%, ALS3 in 14 (35.8%, and CDR1 in 26 (66.6%. In nearly all of the strains, ALS1, HWP1, SAP4–SAP6, LIP1–LIP10, PLB1, and PLB2 were expressed, whereas CDR1 was expressed in 20 (51.3% and ALS3 in 14 (35.8%. In our in vitro model of infection with C. albicans, the clinical strains showed different expression profiles of virulence genes in association with the azole resistance gene CDR1. The results indicate that the strains that infect Mexican patients suffering from VVC are highly virulent and virtually all are insensitive to azoles.

  14. Lipopeptides from Bacillus strain AR2 inhibits biofilm formation by Candida albicans.

    Science.gov (United States)

    Rautela, Ria; Singh, Anil Kumar; Shukla, Abha; Cameotra, Swaranjit Singh

    2014-05-01

    The ability of the human fungal pathogen Candida albicans to reversibly switch between different morphological forms and establish biofilms is crucial for establishing infection. Targeting phenotypic plasticity and biofilm formation in C. albicans represents a new concept for antifungal drug discovery. The present study evaluated the influence of cyclic lipopeptide biosurfactant produced by Bacillus amyloliquefaciens strain AR2 on C. albicans biofilms. The biosurfactant was characterized as a mixture of iturin and fengycin by MALDI-TOF and amino acid analysis. The biosurfactant exhibited concentration dependent growth inhibition and fungicidal activity. The biosurfactant at sub-minimum growth inhibition concentration decreased cell surface hydrophobicity, hindered germ tube formation and reduced the mRNA expression of hyphae-specific gene HWP1 and ALS3 without exhibiting significant growth inhibition. The biosurfactants inhibited biofilm formation in the range of 46-100 % depending upon the concentration and Candida strains. The biosurfactant treatment dislodged 25-100 % of preformed biofilm from polystyrene plates. The biosurfactant retained its antifungal and antibiofilm activity even after exposure to extreme temperature. By virtue of the ability to inhibit germ tube and biofilm formation, two important traits of C. albicans involved in establishing infection, lipopeptides from strain AR2 may represent a potential candidate for developing heat stable anti-Candida drugs.

  15. Sulfonylureas have antifungal activity and are potent inhibitors of Candida albicans acetohydroxyacid synthase.

    Science.gov (United States)

    Lee, Yu-Ting; Cui, Chang-Jun; Chow, Eve W L; Pue, Nason; Lonhienne, Thierry; Wang, Jian-Guo; Fraser, James A; Guddat, Luke W

    2013-01-10

    The sulfonylurea herbicides exert their activity by inhibiting plant acetohydroxyacid synthase (AHAS), the first enzyme in the branched-chain amino acid biosynthesis pathway. It has previously been shown that if the gene for AHAS is deleted in Candida albicans , attenuation of virulence is achieved, suggesting AHAS as an antifungal drug target. Herein, we have cloned, expressed, and purified C. albicans AHAS and shown that several sulfonylureas are inhibitors of this enzyme and possess antifungal activity. The most potent of these compounds is ethyl 2-(N-((4-iodo-6-methoxypyrimidin-2-yl)carbamoyl)sulfamoyl)benzoate (10c), which has a K(i) value of 3.8 nM for C. albicans AHAS and an MIC₉₀ of 0.7 μg/mL for this fungus in cell-based assays. For the sulfonylureas tested there was a strong correlation between inhibitory activity toward C. albicans AHAS and fungicidal activity, supporting the hypothesis that AHAS is the target for their inhibitory activity within the cell.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 biofilms also containing bacteria, with genes encoding secreted aspartyl-proteinases (SAP4/SAP6) and hyphal-wall protein (HWP1) up-regulated (p biofilm infections of RHOE. Multi-species infections exhibited higher hyphal proportions (p biofilms promoted Candida virulence, consideration should be given to the bacterial component when managing denture biofilm associated candidoses.

  18. Role of CaECM25 in cell morphogenesis, cell growth and virulence in Candida albicans

    Institute of Scientific and Technical Information of China (English)

    ZHANG TingTing; LI WanJie; LI Di; WANG Yue; SANG JianLi

    2008-01-01

    Candida albicans is the most prominent opportunistic fungal pathogen in humans. Multiple factors are associated with the virulence of C. albicans, including morphogenesis, cell wall organization and growth rate. Here, we describe the identification and functional characterization of CaECM25, a gene that has not been reported before. We constructed Caecm25△/△ mutants and investigated the role of the gene In morphogenesis, cell wall organization and virulence. CaECM25 deletion resulted in defects in cell separation, a slower growth rate, reduced filamentous growth and attenuated adherence to plastic surfaces. The Caecm25△/△ mutant was also significantly less virulent than wild type when tested for systemic infection in mice. Therefore, CaECM25 plays important roles in morphogenesis, cell wall organization and virulence.

  19. Role of CaECM25 in cell morphogenesis, cell growth and virulence in Candida albicans

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Candida albicans is the most prominent opportunistic fungal pathogen in humans. Multiple factors are associated with the virulence of C. albicans, including morphogenesis, cell wall organization and growth rate. Here, we describe the identification and functional characterization of CaECM25, a gene that has not been reported before. We constructed Caecm25?/? mutants and investigated the role of the gene in morphogenesis, cell wall organization and virulence. CaECM25 deletion resulted in defects in cell separation, a slower growth rate, reduced filamentous growth and attenuated adherence to plastic surfaces. The Caecm25?/? mutant was also significantly less virulent than wild type when tested for systemic infection in mice. Therefore, CaECM25 plays important roles in morphogenesis, cell wall organization and virulence.

  20. Development of DNA probes for Candida albicans

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  2. Triclosan antagonizes fluconazole activity against Candida albicans.

    LENUS (Irish Health Repository)

    Higgins, J

    2012-01-01

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

  3. A Candida albicans early stage biofilm detachment event in rich medium

    Directory of Open Access Journals (Sweden)

    Nantel Andre

    2009-02-01

    Full Text Available Abstract Background Dispersal from Candida albicans biofilms that colonize catheters is implicated as a primary factor in the link between contaminated catheters and life threatening blood stream infections (BSI. Appropriate in vitro C. albicans biofilm models are needed to probe factors that induce detachment events. Results Using a flow through system to culture C. albicans biofilms we characterized a detachment process which culminates in dissociation of an entire early stage biofilm from a silicone elastomer surface. We analyzed the transcriptome response at time points that bracketed an abrupt transition in which a strong adhesive association with the surface is weakened in the initial stages of the process, and also compared batch and biofilm cultures at relevant time points. K means analysis of the time course array data revealed categories of genes with similar patterns of expression that were associated with adhesion, biofilm formation and glycoprotein biosynthesis. Compared to batch cultures the biofilm showed a pattern of expression of metabolic genes that was similar to the C. albicans response to hypoxia. However, the loss of strong adhesion was not obviously influenced by either the availability of oxygen in the medium or at the silicone elastomer surface. The detachment phenotype of mutant strains in which selected genes were either deleted or overexpressed was characterized. The microarray data indicated that changes associated with the detachment process were complex and, consistent with this assessment, we were unable to demonstrate that transcriptional regulation of any single gene was essential for loss of the strong adhesive association. Conclusion The massive dispersal of the early stage biofilm from a biomaterial surface that we observed is not orchestrated at the level of transcriptional regulation in an obvious manner, or is only regulated at this level by a small subpopulation of cells that mediate adhesion to the

  4. In vitro evaluation of antifungal activity of monolaurin against Candida albicans biofilms

    OpenAIRE

    Seleem, Dalia; Chen, Emily; Benso, Bruna; Pardi, Vanessa; Murata, Ramiro M.

    2016-01-01

    Monolaurin (also known as glycerol monolaurate) is a natural compound found in coconut oil and is known for its protective biological activities as an antimicrobial agent. The nature of oral candidiasis and the increased antifungal resistance demand the search for novel antifungal therapeutic agents. In this study, we examine the antifungal activity of monolaurin against Candida albicans biofilms (strain ATCC:SC5314/MYA2876) in vitro and investigate whether monolaurin can alter gene expressio...

  5. Overexpression and mutation as a genetic mechanism of fluconazole resistance in Candida albicans isolated from human immunodeficiency virus patients in Indonesia.

    Science.gov (United States)

    Rosana, Yeva; Yasmon, Andi; Lestari, Delly Chipta

    2015-09-01

    Fluconazole is the standard treatment for oropharyngeal candidiasis, which is the third most common opportunistic infection in human immunodeficiency virus (HIV)/AIDS patients in Indonesia. Overuse of this drug could lead to the emergence of resistance. The objective of this study was to analyse the role of ERG11, CDR1, CDR2 and MDR1 gene overexpression and mutations in the ERG11 gene as a genetic mechanism of fluconazole resistance in Candida albicans isolated from HIV patients in Indonesia. Overexpression of ERG11, CDR1, CDR2 and MDR1 was analysed by real-time reverse transcription PCR, while ERG11 gene mutation analysis was performed using sequencing methods. Seventeen isolates out of 92 strains of C. albicans isolated from 108 HIV patients were found to be resistant to azole antifungals. The highest gene overexpression of ERG11 was found in C. albicans resistant to single fluconazole, while the highest gene overexpression of CDR2 was detected in all isolates of C. albicans resistant to multiple azoles. Amino acid substitutions were observed at six positions, i.e. D116E, D153E, I261V, E266D, V437I and V488I. The amino acid substitution I261V was identified in this study and was probably associated with fluconazole resistance. The combination of overexpression of CDR2 and ERG11 and mutation in the ERG11 gene was found to be a genetic mechanism of fluconazole resistance in C. albicans isolated from HIV patients in Indonesia.

  6. An interspecies regulatory network inferred from simultaneous RNA-seq of Candida albicans invading innate immune cells

    Directory of Open Access Journals (Sweden)

    Lanay eTierney

    2012-03-01

    Full Text Available The ability to adapt to diverse micro-environmental challenges encountered within a host is of pivotal importance to the opportunistic fungal pathogen C. albicans. We have quantified C.albicans and M. musculus gene expression dynamics during phagocytosis by dendritic cells in a genome-wide, time-resolved analysis using simultaneous RNA-seq. A robust network inference map was generated from this dataset using NetGenerator, predicting novel interactions between the host and the pathogen. We experimentally verified predicted interdependent sub-networkscomprising Hap3 in C. albicans, and Ptx3 and Mta2 in M. musculus. Remarkably, binding of recombinant Ptx3 to the C. albicans cell wall was found to regulate the expression of fungal Hap3 target genes as predicted by the network inference model. Pre-incubation of C. albicans with recombinant Ptx3 significantly altered the expression of Mta2 target cytokines such as IL-2 and IL-4 in a Hap3-dependent manner, further suggesting a role for Mta2 in host-pathogen interplay as predicted in the network inference model. We propose an integrated model for the functionality of these sub-networks during fungal invasion of immune cells, according to which binding of Ptx3 to the C. albicans cell wall induces remodelling via fungal Hap3 target genes, thereby altering the immune response to the pathogen. We show the applicability of network inference to predict interactions between host-pathogen pairs, demonstrating the usefulness of this systems biology approach to decipher mechanisms of microbial pathogenesis.

  7. IDENTIFIKASI SPESIES CANDIDA ALBICANS PADA PENDERITA ANGULAR CHEILITIS

    OpenAIRE

    Mu`min, Mulia Sari

    2012-01-01

    2011 Abstrak Candida albicans merupakan jenis Candida yang menginfeksi semua organ tubuh manusia, dapat ditemukan pada semua golongan umur, baik pada pria maupun wanita. Candida albicans merupakan fungi patogen oportunistik yang paling sering menginfeksi rongga mulut. Fungi ini dapat ditemukan pada seluruh permukaan rongga mulut, yaitu lidah (punggung lidah merupakan tempat yang disukai Candida albicans untuk tumbuh dan berkembang biak), pipi, mukosa palatal, plak gigi, karies gigi, flo...

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

    Science.gov (United States)

    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. Interactions Between Candida albicans and Host Interações entre Candida albicans e Hospedeiro

    Directory of Open Access Journals (Sweden)

    Tatiane De Rossi

    2011-06-01

    Full Text Available Candida albicans can cause grave infections in patients who are immunocompromised by diseases, by surgery, or by immunesupresive therapy. The high levels of morbidity and mortality resulting from those infections in hospitalized patients show that C. albicans became a prominent human pathogen. Although the host immune system is the major factor balancing the transition from commensalisms to pathogenicity, several virulence attributes expressed by C. albicans, such as adhesion factors, phenotypic switching, dimorphic behavior, and secretion of hydrolytic enzymes, might contribute to the persistence of colonization as well as the development of symptomatic episodes. Host defense against candidiasis relies mainly on the ingestion and elimination of C. albicans by phagocytic cells, which present receptors Toll-like 4, dectin–1 associated to receptors Toll-like2 and mannose receptors. The cytokine IL-10 (IL-10 produced by phagocytes has a crucial role on susceptibility of host fungal infection, whereas IL-10 produced by regulatory T cells is mainly responsible by commensalisms. In contrast, productions of tumour necrosis factor - α (TNF-α, interleukin–1 β (lL-1 β, (IL-6 and (Il-12 provided protective cell–mediated immunity. The interferon-γ produced by natural killer and TH1 cells stimulates migration of phagocytes and major efficacy on destruction of fungi. In epithelial cells from mucosas the NOD-like receptors and defensins-β cytoplasmatic prevent the translocation of C. albicans from microbiota to tissues, which are modulated by IL-1 β, Il-17 and Il-22 cytokines. to pathogenicity, several virulence attributes expressed by C. albicans, such as adhesion factors, phenotypic switching, dimorphic behavior, and secretion of hydrolytic enzymes, might contribute to the persistence of colonization as well as the development of symptomatic episodes. Host defense against candidiasis relies mainly on the ingestion and elimination of C. albicans

  10. Intestinal colonization with Candida albicans and mucosal immunity

    Institute of Scientific and Technical Information of China (English)

    Xiao-Dong Bai; Xian-Hua Liu; Qing-Ying Tong

    2004-01-01

    AIM: To observe the relationship between intestinal lumen colonization with Candida albicans and mucosal secretory IgA (sIgA).METHODS: A total of 82 specific-pathogen-free mice were divided randomly into control and colonization groups. After Candida albicans were inoculated into specific-pathogenfree mice, the number of Candida albicans adhering to cecum and mucosal membrane was counted. The lymphocyte proliferation in Peyer's patch and in lamina propria was shown by BrdU incorporation, while mucosal sIgA (surface membrane) isotype switch in Peyer's patch was investigated. IgA plasma cells in lamina propria were observed by immunohistochemical staining. Specific IgA antibodies to Candida albicans were measured with ELISA.RESULTS: From d 3 to d 14 after Candida albicans gavaging to mice, the number of Candida albicans colonizing in lumen and adhering to mucosal membrane was sharply reduced.Candida albicans translocation to mesenteric lymph nodes occurred at early time points following gavage administration and disappeared at later time points. Meanwhile, the content of specific IgA was increased obviously. Proliferation and differentiation of lymphocytes in lamina propria were also increased.CONCLUSION: Lymphocytes in lamina propria play an important role in intestinal mucosal immunity of specificpathogen-free mice when they are first inoculated with Candida albicans. The decreasing number of Candida albicans in intestine is related to the increased level of specific IgA antibodies in the intestinal mucus.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shulong; Fu, Yingyuan, E-mail: yingyuanfu@126.com; 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

  12. Detecting CPH1, EFG1 gene expression of planktonic cells and biofilm of Candida albicans with fluorescent quantitative PCR assay%荧光定量PCR检测不同状态下白念珠菌CPH1、EFG1基因的表达

    Institute of Scientific and Technical Information of China (English)

    阳隽; 张天托; 朱家馨

    2012-01-01

    Obejectiv To investigate the role of gene expression of transcription factor CPH1 and EFG1 in biofilm formation by detecting the difference of CPH1 ,EFG1 mRNA expression between biofilm and planktonic cells of C. Albicans . Methods Ten C. Albicans strains isolated from respiratory tract were used. The total RNA of planktonic and biofilm cells were extracted separately, the mRNA expression of CPH1 , EFG1 were measured with fluorescent quantitative PCR assay. The Δ ΔCt thai show relative value of mRNA expression were calculated. Results In this study, the mRNA expression of EFG1 in biofilm cells was 1. 42 ~ 7. 14 times higher than that in planktonic cells ( P 0.05). Conclusion The study show that transcription factors CPHI ,EFG1 participated in the regulation of biofilm formation in clinical isolates, and further research in vivo is needed to provide more proffs.%目的 检测转录因子CPH1和EFG1基因在游离态及生物膜态呼吸道白念珠菌临床分离株的表达差异,探讨其在生物膜形成过程中的作用.方法 选取10株白念珠菌临床分离株,分别提取游离态及生物膜态白念珠菌总RNA,用荧光定量PCR的方法测定两种状态下CPH1和EFG1基因的表达,用△△Ct的方法计算其相对表达量.结果 白念珠菌生物膜态转录因子EFG1的表达是游离态表达水平的1.42 ~7.14倍,差异有显著意义(P<0.05),而转录因子CPH1的表达有8株菌生物膜态较游离态增高,1株降低,1株无明显变化,差异无显著意义(P>0.05).结论 白念珠临床株转录因子CPH1和EFG1参与生物膜形成的调控,并需在体内实验中进一步研究.

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

    Science.gov (United States)

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

    2014-04-01

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

  14. Role of Candida albicans-Secreted Aspartyl Proteinases (Saps in Severe Early Childhood Caries

    Directory of Open Access Journals (Sweden)

    Wenqing Li

    2014-06-01

    Full Text Available Candida albicans is strongly associated with severe early childhood caries (S-ECC. However, the roles of secreted aspartyl proteinases (Saps, an important virulence factor of C. albicans, in the progress of S-ECC are not clear. In our study, the Saps activities were evaluated by the yeast nitrogen base–bovine serum albumi (YNB–BSA agar plate method and by the MTT method with bovine serum albumin (BSA as the substrate. Genotypes of C. albicans and gene expression of Sap1–5 were evaluated. The relationships of Saps activities and genotypes with S-ECC were analyzed. The results showed that enzyme activities of Saps in the S-ECC group were significantly higher than those in the caries free (CF group (p < 0.05. Genotypes A, B and C were detected in the S-ECC group, and genotypes A and C were detected in the CF group. In the genotype A group, Saps activity in the S-ECC group was significantly different from that in the CF group (p < 0.05. The gene expression level of Sap1 in the S-ECC group was significantly higher than that in the CF group (p = 0.001, while Sap4 expression was significantly lower than that in the CF group (p = 0.029. It can be concluded that Sap1–5 are the predominant proteinase genes expressed in C. albicans from dental biofilm and Sap1 may play an important role in the development of S-ECC.

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

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    Eduardo Lopez-Medina

    2015-08-01

    Full Text Available 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.

  16. DNA microarray analysis of fluconazole resistance in a laboratory Candida albicans strain

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Several mechanisms are responsible for the acquired fluconazole (FLC) resistance in Candida albicans. In this study, we developed a FLC-resistant C. albicans strain through serial cultures of a FLC-susceptible C. albicans strain with inhibitory concentrations of FLC. Complimen-tary DNA microarray analysis and real-time reverse tran-scription-polymerase chain reaction were used to investi-gate gene expression changes during the acquisition of azole resistance in the susceptible parental strain and the resis-tant daughter strain. The differentially expressed genes rep-resented functions as diverse as transporters (e.g. CDRI, PDR17), ergosterol biosynthesis (e.g. ERG2, ERG9), sterol metabolism (e.g. ARE2, IPF6464), energy metabolism (e.g. ADH3, AOX2) and transcription factors (e.g. FCR1, ECM22). Functional analysis revealed that energy-depen-dent efflux activity of membrane transporters increased and that ergosterol content decreased with the accumulation of sterol intermediates in the resistant strain as compared with the susceptible strain. We found that a point mutation (N977K) in transcription factor TAC1 that resulted in hy-peractivity of Tac1 could be the reason for overexpression of CDR1, CDR2, and PDR17 in the resistant strain.Furthermore, a single amino acid difference (DI9E) in ERG3 that led to the inactivation of Erg3 could account for both sterol precursor accumulation and the changes in the ex-pression of ergosterol biosynthesis genes in this resistant strain. These findings expand the understanding of poten-tial novel molecular targets of FLC resistance in clinical C.albicans isolates.

  17. Lactobacillus paracasei modulates the immune system of Galleria mellonella and protects against Candida albicans infection

    Science.gov (United States)

    Rossoni, Rodnei Dennis; Fuchs, Beth Burgwyn; de Barros, Patrícia Pimentel; Velloso, Marisol dos Santos; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos; Mylonakis, Eleftherios

    2017-01-01

    Probiotics have been described as a potential strategy to control opportunistic infections due to their ability to stimulate the immune system. Using the non-vertebrate model host Galleria mellonella, we evaluated whether clinical isolates of Lactobacillus spp. are able to provide protection against Candida albicans infection. Among different strains of Lactobacillus paracasei, Lactobacillus rhamnosus and Lactobacillus fermentum, we verified that L. paracasei 28.4 strain had the greatest ability to prolong the survival of larvae infected with a lethal dose of C. albicans. We found that the injection of 107 cells/larvae of L. paracasei into G. mellonella larvae infected by C. albicans increased the survival of these insects compared to the control group (P = 0.0001). After that, we investigated the immune mechanisms involved in the protection against C. albicans infection, evaluating the number of hemocytes and the gene expression of antifungal peptides. We found that L. paracasei increased the hemocyte quantity (2.38 x 106 cells/mL) in relation to the control group (1.29 x 106 cells/mL), indicating that this strain is capable of raising the number of circulating hemocytes into the G. mellonella hemolymph. Further, we found that L. paracasei 28.4 upregulated genes that encode the antifungal peptides galiomicin and gallerymicin. In relation to the control group, L. paracasei 28.4 increased gene expression of galiomicin by 6.67-fold and 17.29-fold for gallerymicin. Finally, we verified that the prophylactic provision of probiotic led to a significant reduction of the number of fungal cells in G. mellonella hemolymph. In conclusion, L. paracasei 28.4 can modulate the immune system of G. mellonella and protect against candidiasis. PMID:28267809

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  20. The fungus Candida albicans tolerates ambiguity at multiple codons

    Directory of Open Access Journals (Sweden)

    João Salvador Simões

    2016-03-01

    Full Text Available 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 3% of leucine and 97% of serine are incorporated at CUG sites 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.

  1. Mutations in transcription factor Mrr2p contribute to fluconazole resistance in clinical isolates of Candida albicans.

    Science.gov (United States)

    Wang, Ying; Liu, Jin-Yan; Shi, Ce; Li, Wen-Jing; Zhao, Yue; Yan, Lan; Xiang, Ming-Jie

    2015-11-01

    The Candida albicans zinc cluster proteins are a family of transcription factors (TFs) that play essential roles in the development of antifungal drug resistance. Gain-of-function mutations in several TFs, such as Tac1p, Mrr1p and Upc2p, have been previously well documented in azole-resistant clinical C. albicans isolates. Mrr2p (multidrug resistance regulator 2) is a novel TF controlling expression of the ABC transporter gene CDR1 and mediating fluconazole resistance. In this study, the relationship between naturally occurring mutations in MRR2 and fluconazole resistance in clinical C. albicans isolates was investigated. Among a group of 20 fluconazole-resistant clinical C. albicans and 10 fluconazole-susceptible C. albicans, 12 fluconazole-resistant isolates overexpressed CDR1 by at least two-fold compared with the fluconazole-susceptible isolates. Of these 12 resistant isolates, three (C7, C9, C15) contained 11 identical missense mutations, 6 of which occurred only in the azole-resistant isolates. The contribution of these mutations to CDR1 overexpression and therefore to fluconazole resistance was further verified by generating recombinant strains containing the mutated MRR2 gene. The mutated MRR2 alleles from isolate C9 contributed to an almost six-fold increase in CDR1 expression and an eight-fold increase in fluconazole resistance; the missense mutations S466L and T470N resulted in an increase in CDR1 expression of more than two-fold and a four-fold increase in fluconazole resistance. In contrast, the other four missense mutations conferred only two- to four-fold increases in fluconazole resistance, with no significant increase in CDR1 expression. These findings provide some insight into the mechanism by which MRR2 regulates C. albicans multidrug resistance.

  2. Molecular Identification of Candida Albicans Isolated From the Oncology Patients at Four University Hospitals in Mazandaran Province (2005-6

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    H. Karami, M.D.

    2007-01-01

    Full Text Available AbstractBackground and Purpose: Early detection of Candida species in body site could improve the survival of the immunosuppressed patients by allowing the initiation of specific treatment while the fungal biomass is still low. The aim of this study was the identification of Candida albicans isolated from the oncology patients by molecular methods.Materials and Methods: Sixty two of Candida albicans isolated identified by phenotypic methods (color of colony on CHROMagar medium, germ-tube formation in horse serum, chlamydospore formation on Cornmeal agar with 1% Tween 80. DNA was extracted by using a glass bead/phenol- chloroform method. The oligonucleotide primer pairs (NL1/NL4 were used to amplify a 620-bp fragment of D1/D2 region of large submit (26s ribosomal DNA gene. PCR-products were electrophoresed in a 1.5% agarose gel. Eighteen PCR-amplified products sequenced and results were evaluated by online BLAST software. Multiple sequence alignment was performed by using online CLUSTAL-W (version 1.83 software.Results: The BLAST search revealed that all of products were Candida albicans. All sequences showed >99% similarity when compared with known reference sequences at the Gene-Bank. Four different strains were obtained of albicans species, including: AA 1622b (13 samples, 24698 (3 samples, TA 62 (1samples and 551 FC (1 sample. A total of 131 nucleotide exchange sites were revealed.Conclusion: The dominant species by phenotypic approaches was Candida albicans. In addition, identification of Candida albicans by (26S rDNA sequencing was 100% concordant to the results obtained by the phenotypic metho

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

    Science.gov (United States)

    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

    2016-10-01

    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.

  4. Participation of Candida albicans transcription factor RLM1 in cell wall biogenesis and virulence.

    Science.gov (United States)

    Delgado-Silva, Yolanda; Vaz, Catarina; Carvalho-Pereira, Joana; Carneiro, Catarina; Nogueira, Eugénia; Correia, Alexandra; Carreto, Laura; Silva, Sónia; Faustino, Augusto; Pais, Célia; Oliveira, Rui; Sampaio, Paula

    2014-01-01

    Candida albicans cell wall is important for growth and interaction with the environment. RLM1 is one of the putative transcription factors involved in the cell wall integrity pathway, which plays an important role in the maintenance of the cell wall integrity. In this work we investigated the involvement of RLM1 in the cell wall biogenesis and in virulence. Newly constructed C. albicans Δ/Δrlm1 mutants showed typical cell wall weakening phenotypes, such as hypersensitivity to Congo Red, Calcofluor White, and caspofungin (phenotype reverted in the presence of sorbitol), confirming the involvement of RLM1 in the cell wall integrity. Additionally, the cell wall of C. albicans Δ/Δrlm1 showed a significant increase in chitin (213%) and reduction in mannans (60%), in comparison with the wild-type, results that are consistent with cell wall remodelling. Microarray analysis in the absence of any stress showed that deletion of RLM1 in C. albicans significantly down-regulated genes involved in carbohydrate catabolism such as DAK2, GLK4, NHT1 and TPS1, up-regulated genes involved in the utilization of alternative carbon sources, like AGP2, SOU1, SAP6, CIT1 or GAL4, and genes involved in cell adhesion like ECE1, ALS1, ALS3, HWP1 or RBT1. In agreement with the microarray results adhesion assays showed an increased amount of adhering cells and total biomass in the mutant strain, in comparison with the wild-type. C. albicans mutant Δ/Δrlm1 strain was also found to be less virulent than the wild-type and complemented strains in the murine model of disseminated candidiasis. Overall, we showed that in the absence of RLM1 the modifications in the cell wall composition alter yeast interaction with the environment, with consequences in adhesion ability and virulence. The gene expression findings suggest that this gene participates in the cell wall biogenesis, with the mutant rearranging its metabolic pathways to allow the use of alternative carbon sources.

  5. Participation of Candida albicans transcription factor RLM1 in cell wall biogenesis and virulence.

    Directory of Open Access Journals (Sweden)

    Yolanda Delgado-Silva

    Full Text Available Candida albicans cell wall is important for growth and interaction with the environment. RLM1 is one of the putative transcription factors involved in the cell wall integrity pathway, which plays an important role in the maintenance of the cell wall integrity. In this work we investigated the involvement of RLM1 in the cell wall biogenesis and in virulence. Newly constructed C. albicans Δ/Δrlm1 mutants showed typical cell wall weakening phenotypes, such as hypersensitivity to Congo Red, Calcofluor White, and caspofungin (phenotype reverted in the presence of sorbitol, confirming the involvement of RLM1 in the cell wall integrity. Additionally, the cell wall of C. albicans Δ/Δrlm1 showed a significant increase in chitin (213% and reduction in mannans (60%, in comparison with the wild-type, results that are consistent with cell wall remodelling. Microarray analysis in the absence of any stress showed that deletion of RLM1 in C. albicans significantly down-regulated genes involved in carbohydrate catabolism such as DAK2, GLK4, NHT1 and TPS1, up-regulated genes involved in the utilization of alternative carbon sources, like AGP2, SOU1, SAP6, CIT1 or GAL4, and genes involved in cell adhesion like ECE1, ALS1, ALS3, HWP1 or RBT1. In agreement with the microarray results adhesion assays showed an increased amount of adhering cells and total biomass in the mutant strain, in comparison with the wild-type. C. albicans mutant Δ/Δrlm1 strain was also found to be less virulent than the wild-type and complemented strains in the murine model of disseminated candidiasis. Overall, we showed that in the absence of RLM1 the modifications in the cell wall composition alter yeast interaction with the environment, with consequences in adhesion ability and virulence. The gene expression findings suggest that this gene participates in the cell wall biogenesis, with the mutant rearranging its metabolic pathways to allow the use of alternative carbon sources.

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

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    Katharine S Dobb

    Full Text Available 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.

  7. Melittin induces apoptotic features in Candida albicans

    Energy Technology Data Exchange (ETDEWEB)

    Park, Cana [School of Life Sciences and Biotechnology, College of Natural Sciences, Kyungpook National University, 1370 Sankyuk-dong, Puk-ku, Daegu 702-701 (Korea, Republic of); Lee, Dong Gun, E-mail: dglee222@knu.ac.kr [School of Life Sciences and Biotechnology, College of Natural Sciences, Kyungpook National University, 1370 Sankyuk-dong, Puk-ku, Daegu 702-701 (Korea, Republic of)

    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.

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

    Directory of Open Access Journals (Sweden)

    Govindsamy Vediyappan

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

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

    Science.gov (United States)

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

    2002-06-01

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

  10. Mucosal damage and neutropenia are required for Candida albicans dissemination.

    Directory of Open Access Journals (Sweden)

    Andrew Y Koh

    2008-02-01

    Full Text Available Candida albicans fungemia in cancer patients is thought to develop from initial gastrointestinal (GI colonization with subsequent translocation into the bloodstream after administration of chemotherapy. It is unclear what components of the innate immune system are necessary for preventing C. albicans dissemination from the GI tract, but we have hypothesized that both neutropenia and GI mucosal damage are critical for allowing widespread invasive C. albicans disease. We investigated these parameters in a mouse model of C. albicans GI colonization that led to systemic spread after administration of immunosuppression and mucosal damage. After depleting resident GI intestinal flora with antibiotic treatment and achieving stable GI colonization levels of C. albicans, it was determined that systemic chemotherapy with cyclophosphamide led to 100% mortality, whereas selective neutrophil depletion, macrophage depletion, lymphopenia or GI mucosal disruption alone resulted in no mortality. Selective neutrophil depletion combined with GI mucosal disruption led to disseminated fungal infection and 100% mortality ensued. GI translocation and dissemination by C. albicans was also dependent on the organism's ability to transform from the yeast to the hyphal form. This mouse model of GI colonization and fungemia is useful for studying factors of innate host immunity needed to prevent invasive C. albicans disease as well as identifying virulence factors that are necessary for fungal GI colonization and dissemination. The model may also prove valuable for evaluating therapies to control C. albicans infections.

  11. Genome-wide expression profiling of the response to terbinafine in Candida albicans using a cDNA microarray analysis

    Institute of Scientific and Technical Information of China (English)

    ZENG Yue-bin; QIAN Yuan-shu; MA Lian; GU Hong-ni

    2007-01-01

    Background Candida albicans is the most frequently seen opportunistic human fungal pathogen. Terbinafine is an allylamine antifungal agent that has been proven to have high clinical efficacy in the therapy of fungal infections, the mechanism of action of terbinafine involves the specific inhibition of fungal squalene epoxidase, resulting in ergosterol deficiency and accumulation of intracellular squalene. We used cDNA microarray analysis technology to monitor global expression profile changes of Candida albicans genes in response to terbinafine treatment, and we anticipated a panoramic view of the responses of Candida albicans cells to the representatives of allylamine antifungal agents at the molecular level in an effort to identify drug class-specific and mechanism-independent changes in gene expression.Methods Candida albicans strain ATCC 90028 was exposed to either medium alone or terbinafine at a concentration equivalent to the 1/2 minimal inhibitory concentrations (MICs, 4 mg/L) for 90 minutes. RNA was isolated and gene expression profiles were compared to identify the changes in the gene expression profile using a cDNA microarray analysis. Differential expression of 10 select genes detected by cDNA microarray analysis was confirmed by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR).Results A total of 222 genes were found to be responsive to terbinafine, including 121 up-regulated genes and 101 down-regulated genes. These included genes encoding membrane transport proteins belonging to the members of the ATP-binding cassette (ABC) or major facilitator superfamily (MFS; CDR1, AGP2, GAP6, PHO84, HOL3, FCY23, VCX1),genes involved in stress response and detoxification (CDR1, AGP2, HOL3), and gene involved in the ergosterol biosynthesis pathway (ERG12). The results of semi-quantitative RT-PCR were consistent with that of the cDNA microarray analysis.Conclusions The up-regulation of the gene encoding the multidrug resistance efflux pump

  12. Effects of Two Curcuminoids on Candida albicans

    Institute of Scientific and Technical Information of China (English)

    ZHANG Da; LUO Jiao-yang; YAN Dan; JIN Cheng; DONG Xiao-ping; XIAO Xiao-he

    2012-01-01

    Objective To investigate and compare the action of curcuminoids on the causal pathogens of Candida albicans growth.Methods The effects of curcumin (CUR) and demethoxycurcumin (DMC) on C.albicans growth were first investigated and compared by microcalorimetry coupled with multiple analytical methods.The quantitative thermo-kinetic parameters obtained from these curves were analyzed to show difference of the actions.Results By analyzing the main parameters screened from principal component analysis together with 50% inhibiting concentration values,it was demonstrated that both CUR and DMC showed good antifungal activities and CUR was stronger.It was further concluded from structure-activity relationship that the existence of methoxy group might enhance lipophilicity of the mother nucleus,which made it easier for the molecular to enter into the cell membrane of fungi to inhibit its growth.Conclusion This study provides a new method for screening new antifungal agents with high efficacy and low toxicity.Meanwhile,it contributes to the application of curcuminoids as food additive,colorant,and drug.Microcalorimetry is real-time,online,and dynamic,and it could be used to characterize the subtle difference among the effects of synthetic and natural products on the vital process of fungi.

  13. The MAP kinase-activated protein kinase Rck2p regulates cellular responses to cell wall stresses, filamentation and virulence in the human fungal pathogen Candida albicans.

    Science.gov (United States)

    Li, Xichuan; Du, Wei; Zhao, Jingwen; Zhang, Lilin; Zhu, Zhiyan; Jiang, Linghuo

    2010-06-01

    Rck2p is the Hog1p-MAP kinase-activated protein kinase required for the attenuation of protein synthesis in response to an osmotic challenge in Saccharomyces cerevisiae. Rck2p also regulates rapamycin sensitivity in both S. cerevisiae and Candida albicans. In this study, we demonstrate that the deletion of CaRCK2 renders C. albicans cells sensitive to, and CaRck2p translocates from the cytosol to the nucleus in response to, cell wall stresses caused by Congo red, Calcoflor White, elevated heat and zymolyase. However, the kinase activity of CaRck2p is not required for the cellular response to these cell wall stresses. Furthermore, transcripts of cell wall protein-encoding genes CaBGL2, CaHWP1 and CaXOG1 are reduced in C. albicans cells lacking CaRCK2. The deletion of CaRCK2 also reduces the in vitro filamentation of C. albicans and its virulence in a mouse model of systemic candidasis. The kinase activity of CaRck2p is required for the virulence, but not for the in vitro filamentation, in C. albicans. Therefore, Rck2p regulates cellular responses to cell wall stresses, filamentation and virulence in the human fungal pathogen C. albicans.

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

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    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.

  15. Candida albicans autophagy, no longer a bystander: Its role in tolerance to ER stress-related antifungal drugs.

    Science.gov (United States)

    Yu, Qilin; Jia, Chang; Dong, Yijie; Zhang, Bing; Xiao, Chenpeng; Chen, Yulu; Wang, Yuzhou; Li, Xiaoling; Wang, Lei; Zhang, Biao; Li, Mingchun

    2015-08-01

    Autophagy is a degradation process involved in pathogenicity of many pathogenic fungi. However, its roles in Candida albicans, the leading fungal pathogen in human beings, remain to be detailed. Most recently, we found that endoplasmic reticulum (ER) stress-inducing conditions led to transcriptional up-regulation of C. albicans autophagy-related (ATG) genes, implying a possible link between autophagy and ER stress response in this pathogen. Using a series of C. albicans ATG mutants and autophagy reporting systems, we found that both treatment of ER stress-related drugs and loss of the ER calcium pump Spf1 promoted autophagic flux of Atg8 and Lap41 (a homologue of Saccharomyces cerevisiae Ape1), indicating that these conditions induce autophagy. Moreover, deletion of ATG genes in the spf1Δ/Δ mutant rendered cells hypersensitive to these drugs and caused activation of UPR, revealing a role of autophagy in alleviating ER stress. In addition, only treatment of tunicamycin and loss of Spf1 in combination increased autophagic flux of the ER component Sec63, suggesting that most of the ER stress-related conditions cause non-selective autophagy rather than selective ER phagy. This study uncovers the important role of C. albicans autophagy in ER stress response and tolerance to antifungal drugs.

  16. The role of nutrient regulation and the Gpa2 protein in the mating pheromone response of C. albicans.

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    Bennett, Richard J; Johnson, Alexander D

    2006-10-01

    Although traditionally classified as asexual, the human fungal pathogen Candida albicans can undergo highly efficient mating. A key component of this mating is the response to pheromone, which is mediated by a conserved kinase cascade that transduces the signal from the pheromone receptor to a transcriptional response in the nucleus. In this paper we show (i) that the detailed response of C. albicans to the alpha pheromone differs among clinical isolates, (ii) that the response depends critically on nutritional conditions, (iii) that the entire response is mediated by the Ste2 receptor, and (iv) that, in terms of genes induced, the response to alpha pheromone in C. albicans shows only marginal overlap with the response in Saccharomyces cerevisiae. We further investigated the nutritional control of pheromone induction and identify the GPA2 gene as a critical component. We found that Deltagpa2/Deltagpa2 mutants are hypersensitive to pheromone and, unlike wild-type strains, show efficient cell cycle arrest (including the formation of characteristic halos on solid medium) in response to mating pheromone. These results indicate that C. albicans, like several other fungal species but unlike S. cerevisiae, integrates signals from a nutrient-sensing pathway with those of the pheromone response MAP kinase pathway to generate the final transcriptional response.

  17. Therapeutic potential of thiazolidinedione-8 as an antibiofilm agent against Candida albicans.

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    Mark Feldman

    Full Text Available Candida albicans is known as a commensal microorganism but it is also the most common fungal pathogen in humans, causing both mucosal and systemic infections. Biofilm-associated C. albicans infections present clinically important features due to their high levels of resistance to traditional antifungal agents. Quorum sensing is closely associated with biofilm formation and increasing fungal pathogenicity. We investigated the ability of the novel bacterial quorum sensing quencher thiazolidinedione-8 (S-8 to inhibit the formation of, and eradication of mature C. albicans biofilms. In addition, the capability of S-8 to alter fungal adhesion to mammalian cells was checked. S-8 exhibited specific antibiofilm and antiadhesion activities against C. albicans, at four- to eightfold lower concentrations than the minimum inhibitory concentration (MIC. Using fluorescence microscopy, we observed that S-8 dose-dependently reduces C. albicans-GFP binding to RAW macrophages. S-8 at sub-MICs also interfered with fungal morphogenesis by inhibiting the yeast-to-hyphal form transition. In addition, the tested agent strongly affected fungal cell wall characteristics by modulating its hydrophobicity. We evaluated the molecular mode of S-8 antibiofilm and antiadhesion activities using real-time RT-PCR. The expression levels of genes associated with biofilm formation, adhesion and filamentation, HWP1, ALS3 and EAP1, respectively, were dose-dependently downregulated by S-8. Transcript levels of UME6, responsible for long-term hyphal maintenance, were also significantly decreased by the tested agent. Both signaling pathways of hyphal formation-cAMP-PKA and MAPK-were interrupted by S-8. Their upstream general regulator RAS1 was markedly suppressed by S-8. In addition, the expression levels of MAPK cascade components CST20, HST7 and CPH1 were downregulated by S-8. Finally, transcriptional repressors of filament formation, TUP1 and NRG1, were dramatically upregulated by our

  18. AI-2 of Aggregatibacter actinomycetemcomitans Inhibits Candida albicans Biofilm Formation

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    Endang W. Bachtiar

    2014-07-01

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

  19. Candida species biofilm and Candida albicans ALS3 polymorphisms in clinical isolates

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    Ariane Bruder-Nascimento

    2014-12-01

    Full Text Available 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. Functional characterization of the small heat shock protein Hsp12p from Candida albicans.

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    Man-Shun Fu

    Full Text Available Hsp12p is considered to be a small heat shock protein and conserved among fungal species. To investigate the expression of this heat shock protein in the fungal pathogen Candida albicans we developed an anti-CaHsp12p antibody. We show that this protein is induced during stationary phase growth and under stress conditions including heat shock, osmotic, oxidative and heavy metal stress. Furthermore, we find that CaHsp12p expression is influenced by the quorum sensing molecule farnesol, the change of CO(2 concentration and pH. Notably we show that the key transcription factor Efg1p acts as a positive regulator of CaHsp12p in response to heat shock and oxidative stress and demonstrate that CaHsp12p expression is additionally modulated by Hog1p and the cAMP-PKA signaling pathway. To study the function of Hsp12p in C. albicans we generated a null mutant, in which all four CaHSP12 genes have been deleted. Phenotypic analysis of the strain shows that CaHSP12 is not essential for stress resistance, morphogenesis or virulence when tested in a Drosophila model of infection. However, when overexpressed, CaHSP12 significantly enhanced cell-cell adhesion, germ tube formation and susceptibility to azole antifungal agents whilst desensitizing C. albicans to the quorum sensing molecule farnesol.

  1. Candida species biofilm and Candida albicans ALS3 polymorphisms in clinical isolates.

    Science.gov (United States)

    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.

  2. Co-occurence of filamentation defects and impaired biofilms in Candida albicans protein kinase mutants.

    Science.gov (United States)

    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.

  3. Synergistic Interactions of Eugenol-tosylate and Its Congeners with Fluconazole against Candida albicans.

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    Ahmad, Aijaz; Wani, Mohmmad Younus; Khan, Amber; Manzoor, Nikhat; Molepo, Julitha

    2015-01-01

    We previously reported the antifungal properties of a monoterpene phenol "Eugenol" against different Candida strains and have observed that the addition of methyl group to eugenol drastically increased its antimicrobial potency. Based on the results and the importance of medicinal synthetic chemistry, we synthesized eugenol-tosylate and its congeners (E1-E6) and tested their antifungal activity against different clinical fluconazole (FLC)- susceptible and FLC- resistant C. albicans isolates alone and in combination with FLC by determining fractional inhibitory concentration indices (FICIs) and isobolograms calculated from microdilution assays. Minimum inhibitory concentration (MIC) results confirmed that all the tested C. albicans strains were variably susceptible to the semi-synthetic derivatives E1-E6, with MIC values ranging from 1-62 μg/ml. The test compounds in combination with FLC exhibited either synergy (36%), additive (41%) or indifferent (23%) interactions, however, no antagonistic interactions were observed. The MICs of FLC decreased 2-9 fold when used in combination with the test compounds. Like their precursor eugenol, all the derivatives showed significant impairment of ergosterol biosynthesis in all C. albicans strains coupled with down regulation of the important ergosterol biosynthesis pathway gene-ERG11. The results were further validated by docking studies, which revealed that the inhibitors snugly fitting the active site of the target enzyme, mimicking fluconazole, may well explain their excellent inhibitory activity. Our results suggest that these compounds have a great potential as antifungals, which can be used as chemosensitizing agents with the known antifungal drugs.

  4. Total Protein Profile and Drug Resistance in Candida albicans Isolated from Clinical Samples

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    Kamal Uddin Zaidi

    2016-01-01

    Full Text Available This study was done to assess the antifungal susceptibility of clinical isolates of Candida albicans and to evaluate its total protein profile based on morphological difference on drug resistance. Hundred and twenty clinical isolates of C. albicans from various clinical specimens were tested for susceptibility against four antifungal agents, namely, fluconazole, itraconazole, amphotericin B, and ketoconazole. A significant increase of drug resistance in clinical isolates of C. albicans was observed. The study showed 50% fluconazole and itraconazole resistance at 32 μg mL−1 with a MIC50 and MIC90 values at 34 and 47 and 36 and 49 μg mL−1, respectively. All isolates were sensitive to amphotericin B and ketoconazole. The SDS-PAGE protein profile showed a prevalent band of ~52.5 kDa, indicating overexpression of gene in 72% strains with fluconazole resistance. Since the opportunistic infections of Candida spp. are increasing along with drug resistance, the total protein profile will help in understanding the evolutionary changes in drug resistance and also to characterize them.

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

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

    2013-01-01

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

  6. Encapsulation of Antifungals in Micelles Protects Candida albicans during Gall-Bladder Infection

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    Hsieh, Shih-Hung; Brunke, Sascha; Brock, Matthias

    2017-01-01

    Candida albicans is a dimorphic fungus that colonizes human mucosal surfaces with the potential to cause life-threatening invasive candidiasis. Studies on systemic candidiasis in a murine infection model using in vivo real-time bioluminescence imaging revealed persistence of C. albicans in the gall bladder under antifungal therapy. Preliminary analyses showed that bile conferred resistance against a wide variety of antifungals enabling survival in this cryptic host niche. Here, bile and its components were studied for their ability to reduce antifungal efficacy in order to elucidate the underlying mechanism of protection. While unconjugated bile salts were toxic to C. albicans, taurine, or glycine conjugated bile salts were well tolerated and protective against caspofungin and amphotericin B when exceeding their critical micellar concentration. Microarray experiments indicated that upregulation of genes generally known to mediate antifungal protection is not involved in the protection process. In contrast, rhodamine 6G and crystal violet in- and efflux experiments indicated encapsulation of antifungals in micelles, thereby reducing their bioavailability. Furthermore, farnesol sensing was abolished in the presence of conjugated bile salts trapping C. albicans cells in the hyphal morphology. This suggests that bioavailability of amphiphilic and hydrophobic compounds is reduced in the presence of bile. In contrast, small and hydrophilic molecules, such as cycloheximide, flucytosine, or sodium azide kept their antifungal properties. We therefore conclude that treatment of gall bladder and bile duct infections is hampered by the ability of bile salts to encapsulate antifungals in micelles. As a consequence, treatment of gall bladder or bile duct infections should favor the use of small hydrophilic drugs that are not solubilised in micelles. PMID:28203228

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

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    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.

  8. Molecular mechanisms associated with Fluconazole resistance in clinical Candida albicans isolates from India.

    Science.gov (United States)

    Mane, Arati; Vidhate, Pallavi; Kusro, Chanchal; Waman, Vaishali; Saxena, Vandana; Kulkarni-Kale, Urmila; Risbud, Arun

    2016-02-01

    Resistance to azole antifungals is a significant problem in Candida albicans. An understanding of resistance at molecular level is essential for the development of strategies to tackle resistance and rationale design of newer antifungals and target-based molecular approaches. This study presents the first evaluation of molecular mechanisms associated with fluconazole resistance in clinical C.albicans isolates from India. Target site (ERG11) alterations were determined by DNA sequencing, whereas real-time PCRs were performed to quantify target and efflux pump genes (CDR1, CDR2, MDR1) in 87 [Fluconazole susceptible (n = 30), susceptible-dose dependent (n = 30) and resistant (n = 27)] C.albicans isolates. Cross-resistance to fluconazole, ketoconazole and itraconazole was observed in 74.1% isolates. Six amino acid substitutions were identified, including 4 (E116D, F145L, E226D, I437V) previously reported ones and 2 (P406L, Q474H) new ones. CDR1 over-expression was seen in 77.7% resistant isolates. CDR2 was exclusively expressed with CDR1 and their concomitant over-expression was associated with azole cross-resistance. MDR1 and ERG11 over-expression did not seem to be associated with resistance. Our results show that drug efflux mediated by Adenosine-5'-triphosphate (ATP)-binding cassette transporters, especially CDR1 is the predominant mechanism of fluconazole resistance and azole cross-resistance in C. albicans and indicate the need for research directed towards developing strategies to tackle efflux mediated resistance to salvage azoles.

  9. Anion Exchanger 2 Regulates Dectin-1-Dependent Phagocytosis and Killing of Candida albicans.

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    Katia Urso

    Full Text Available Anion exchanger 2 (Ae2; gene symbol, Slc4a2 is a plasma membrane Cl-/HCO3- exchanger expressed in the gastrointestinal tract, kidney and bone. We have previously shown that Ae2 is required for the function of osteoclasts, bone resorbing cells of the macrophage lineage, to maintain homeostatic cytoplasmic pH and electroneutrality during acid secretion. Macrophages require endosomal acidification for pathogen killing during the process known as phagocytosis. Chloride is thought to be the principal ion responsible for maintaining electroneutrality during organelle acidification, but whether Cl-/HCO3- exchangers such as Ae2 contribute to macrophage function is not known. In this study we investigated the role of Ae2 in primary macrophages during phagocytosis. We find that Ae2 is expressed in macrophages where it regulates intracellular pH and the binding of Zymosan, a fungal cell wall derivative. Surprisingly, the transcription and surface expression of Dectin-1, the major phagocytic receptor for Candida albicans (C. albicans and Zymosan, is reduced in the absence of Ae2. As a consequence, Zymosan-induced Tnfα expression is also impaired in Ae2-deficient macrophages. Similar to Ae2 deficiency, pharmacological alkalinization of lysosomal pH with bafilomycin A decreases both Dectin-1 mRNA and cell surface expression. Finally, Ae2-deficient macrophages demonstrate defective phagocytosis and killing of the human pathogenic fungus C. albicans. Our results strongly suggest that Ae2 is a critical factor in the innate response to C. albicans. This study represents an important contribution to a better understanding of how Dectin-1 expression and fungal clearance is regulated.

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

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    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. Analysis of Repair Mechanisms following an Induced Double-Strand Break Uncovers Recessive Deleterious Alleles in the Candida albicans Diploid Genome

    Science.gov (United States)

    Feri, Adeline; Loll-Krippleber, Raphaël; Commere, Pierre-Henri; Maufrais, Corinne; Sertour, Natacha; Schwartz, Katja; Sherlock, Gavin; Bougnoux, Marie-Elisabeth

    2016-01-01

    ABSTRACT The diploid genome of the yeast Candida albicans is highly plastic, exhibiting frequent loss-of-heterozygosity (LOH) events. To provide a deeper understanding of the mechanisms leading to LOH, we investigated the repair of a unique DNA double-strand break (DSB) in the laboratory C. albicans SC5314 strain using the I-SceI meganuclease. Upon I-SceI induction, we detected a strong increase in the frequency of LOH events at an I-SceI target locus positioned on chromosome 4 (Chr4), including events spreading from this locus to the proximal telomere. Characterization of the repair events by single nucleotide polymorphism (SNP) typing and whole-genome sequencing revealed a predominance of gene conversions, but we also observed mitotic crossover or break-induced replication events, as well as combinations of independent events. Importantly, progeny that had undergone homozygosis of part or all of Chr4 haplotype B (Chr4B) were inviable. Mining of genome sequencing data for 155 C. albicans isolates allowed the identification of a recessive lethal allele in the GPI16 gene on Chr4B unique to C. albicans strain SC5314 which is responsible for this inviability. Additional recessive lethal or deleterious alleles were identified in the genomes of strain SC5314 and two clinical isolates. Our results demonstrate that recessive lethal alleles in the genomes of C. albicans isolates prevent the occurrence of specific extended LOH events. While these and other recessive lethal and deleterious alleles are likely to accumulate in C. albicans due to clonal reproduction, their occurrence may in turn promote the maintenance of corresponding nondeleterious alleles and, consequently, heterozygosity in the C. albicans species. PMID:27729506

  12. Analysis of Repair Mechanisms following an Induced Double-Strand Break Uncovers Recessive Deleterious Alleles in the Candida albicans Diploid Genome.

    Science.gov (United States)

    Feri, Adeline; Loll-Krippleber, Raphaël; Commere, Pierre-Henri; Maufrais, Corinne; Sertour, Natacha; Schwartz, Katja; Sherlock, Gavin; Bougnoux, Marie-Elisabeth; d'Enfert, Christophe; Legrand, Mélanie

    2016-10-11

    The diploid genome of the yeast Candida albicans is highly plastic, exhibiting frequent loss-of-heterozygosity (LOH) events. To provide a deeper understanding of the mechanisms leading to LOH, we investigated the repair of a unique DNA double-strand break (DSB) in the laboratory C. albicans SC5314 strain using the I-SceI meganuclease. Upon I-SceI induction, we detected a strong increase in the frequency of LOH events at an I-SceI target locus positioned on chromosome 4 (Chr4), including events spreading from this locus to the proximal telomere. Characterization of the repair events by single nucleotide polymorphism (SNP) typing and whole-genome sequencing revealed a predominance of gene conversions, but we also observed mitotic crossover or break-induced replication events, as well as combinations of independent events. Importantly, progeny that had undergone homozygosis of part or all of Chr4 haplotype B (Chr4B) were inviable. Mining of genome sequencing data for 155 C. albicans isolates allowed the identification of a recessive lethal allele in the GPI16 gene on Chr4B unique to C. albicans strain SC5314 which is responsible for this inviability. Additional recessive lethal or deleterious alleles were identified in the genomes of strain SC5314 and two clinical isolates. Our results demonstrate that recessive lethal alleles in the genomes of C. albicans isolates prevent the occurrence of specific extended LOH events. While these and other recessive lethal and deleterious alleles are likely to accumulate in C. albicans due to clonal reproduction, their occurrence may in turn promote the maintenance of corresponding nondeleterious alleles and, consequently, heterozygosity in the C. albicans species.

  13. Analysis of Repair Mechanisms following an Induced Double-Strand Break Uncovers Recessive Deleterious Alleles in the Candida albicans Diploid Genome

    Directory of Open Access Journals (Sweden)

    Adeline Feri

    2016-10-01

    Full Text Available The diploid genome of the yeast Candida albicans is highly plastic, exhibiting frequent loss-of-heterozygosity (LOH events. To provide a deeper understanding of the mechanisms leading to LOH, we investigated the repair of a unique DNA double-strand break (DSB in the laboratory C. albicans SC5314 strain using the I-SceI meganuclease. Upon I-SceI induction, we detected a strong increase in the frequency of LOH events at an I-SceI target locus positioned on chromosome 4 (Chr4, including events spreading from this locus to the proximal telomere. Characterization of the repair events by single nucleotide polymorphism (SNP typing and whole-genome sequencing revealed a predominance of gene conversions, but we also observed mitotic crossover or break-induced replication events, as well as combinations of independent events. Importantly, progeny that had undergone homozygosis of part or all of Chr4 haplotype B (Chr4B were inviable. Mining of genome sequencing data for 155 C. albicans isolates allowed the identification of a recessive lethal allele in the GPI16 gene on Chr4B unique to C. albicans strain SC5314 which is responsible for this inviability. Additional recessive lethal or deleterious alleles were identified in the genomes of strain SC5314 and two clinical isolates. Our results demonstrate that recessive lethal alleles in the genomes of C. albicans isolates prevent the occurrence of specific extended LOH events. While these and other recessive lethal and deleterious alleles are likely to accumulate in C. albicans due to clonal reproduction, their occurrence may in turn promote the maintenance of corresponding nondeleterious alleles and, consequently, heterozygosity in the C. albicans species.

  14. A study on relationship between the expression of CDR gene in Candida albicans and fluconazole susceptibility test in vitro%白色念珠菌CDR基因表达与氟康唑体外药敏试验的关系研究

    Institute of Scientific and Technical Information of China (English)

    卜兴胜; 曹毅; 汪浙炯

    2014-01-01

    目的:调查白色念珠菌临床株对氟康唑的耐药情况,研究白色念珠菌临床耐药基因的表达与氟康唑耐药之间的关系。方法采用M27-A2微量肉汤稀释法,对某院微生物实验室2010年分离保存的221株来自就诊患者的痰、中断尿、粪便和咽拭子的白色念珠菌进行氟康唑MIC值测定。以白色念珠菌18S RNA为内参照,采用RT-PCR技术观察比较耐药株和敏感株组在不同氟康唑浓度下CDR1和CDR2基因的转录水平。结果221株白色念珠菌中,有57.47%(127株)对氟康唑敏感,10.86%(24株)剂量依赖敏感,31.67%(70株)耐药。不同药物浓度作用下,耐药株组CDR1和CDR2的表达量相对要高于敏感株组(P<0.05)。结论白色念珠球菌对氟康唑耐药率较高,耐药株组CDR1和CDR2表达量高于敏感株组。%Objective ToinvestigatethefluconazoleresistanceofclinicalstrainsofCandidaalbicansandtoexplorethe relationshipbetweenclinicaldrugresistance(CDR)geneofCandidaalbicansandfluconazoleresistance.Methods Using the M27-A2 micro broth dilution method,221 strains of Candida albicans from sputum separation,interrupt urine,feces and throat swabs which conserved in our laboratory during the year 2010 were measured with fluconazole MIC value. Candida albicans 18S RNA was used as internal reference,the transcription levels of CDR1 and CDR2 gene in resistant and sensitive strain groups were compared under different fluconazole concentrations with RT-PCR technique.Results Amongtherandomlyselected221strainsofCandidaalbicans,127(57.47%)strainsweresusceptibletofluconazole,24 (10.86%)strains were sensitive dependence on dose and 70 (31.67%) strains were resistance.Under different concentration,the expression of CDR1 and CDR2 in resistant strain group was significantly higher than that of sensitive straingroup(P<0.05).Conclusion ThefluconazoleresistantrateofCandidaalbicansisrelativehighandthe expression of CDR1 and CDR2 in

  15. Differential filamentation of Candida albicans and Candida dubliniensis Is governed by nutrient regulation of UME6 expression.

    LENUS (Irish Health Repository)

    O'Connor, Leanne

    2010-09-01

    Candida dubliniensis is closely related to Candida albicans; however, it is responsible for fewer infections in humans and is less virulent in animal models of infection. C. dubliniensis forms fewer hyphae in vivo, and this may contribute to its reduced virulence. In this study we show that, unlike C. albicans, C. dubliniensis fails to form hyphae in yeast extract-peptone-dextrose (YPD) medium supplemented with 10% (vol\\/vol) fetal calf serum (YPDS medium). However, C. dubliniensis filaments in water plus 10% (vol\\/vol) fetal calf serum (WS), and this filamentation is inhibited by the addition of peptone and glucose. Repression of filamentation in YPDS medium could be partly overcome by preculture in synthetic Lee\\'s medium. Unlike C. albicans, inoculation of C. dubliniensis in YPDS medium did not result in increased UME6 transcription. However, >100-fold induction of UME6 was observed when C. dubliniensis was inoculated in nutrient-poor WS medium. The addition of increasing concentrations of peptone to WS medium had a dose-dependent effect on reducing UME6 expression. Transcript profiling of C. dubliniensis hyphae in WS medium identified a starvation response involving expression of genes in the glyoxylate cycle and fatty acid oxidation. In addition, a core, shared transcriptional response with C. albicans could be identified, including expression of virulence-associated genes including SAP456, SAP7, HWP1, and SOD5. Preculture in nutrient-limiting medium enhanced adherence of C. dubliniensis, epithelial invasion, and survival following coculture with murine macrophages. In conclusion, C. albicans, unlike C. dubliniensis, appears to form hyphae in liquid medium regardless of nutrient availability, which may account for its increased capacity to cause disease in humans.

  16. A recently evolved transcriptional network controls biofilm development in Candida albicans.

    Science.gov (United States)

    Nobile, Clarissa J; Fox, Emily P; Nett, Jeniel E; Sorrells, Trevor R; Mitrovich, Quinn M; Hernday, Aaron D; Tuch, Brian B; Andes, David R; Johnson, Alexander D

    2012-01-20

    A biofilm is an organized, resilient group of microbes in which individual cells acquire properties, such as drug resistance, that are distinct from those observed in suspension cultures. Here, we describe and analyze the transcriptional network controlling biofilm formation in the pathogenic yeast Candida albicans, whose biofilms are a major source of medical device-associated infections. We have combined genetic screens, genome-wide approaches, and two in vivo animal models to describe a master circuit controlling biofilm formation, composed of six transcription regulators that form a tightly woven network with ∼1,000 target genes. Evolutionary analysis indicates that the biofilm network has rapidly evolved: genes in the biofilm circuit are significantly weighted toward genes that arose relatively recently with ancient genes being underrepresented. This circuit provides a framework for understanding many aspects of biofilm formation by C. albicans in a mammalian host. It also provides insights into how complex cell behaviors can arise from the evolution of transcription circuits.

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

    Science.gov (United States)

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

    Science.gov (United States)

    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.

  19. "PCR- Detection of Candida albicans in Blood Using a New Primer Pair to Diagnosis of Systemic Candidiasis"

    Directory of Open Access Journals (Sweden)

    SH Mirhendi

    2003-07-01

    Full Text Available The opportunistic pathogen C.albicans is able to cause disseminated infections in immunocompromised patients. Microbiological methods for the diagnosis of invasive candidiasis have many problems including low sensitivity, requirement to invasive clinical sampling such as biopsies or multiple blood cultures and need to expertise laboratory stuff. Since PCR has proven to be a powerful tool in the early diagnosis of several infectious diseases, we applied this approach as a rapid and sensitive method in detection of C.albicans cells in blood samples, for establishment a clinically useful method in diagnosing systemic candidiasis. DNA were extracted from blood samples seeded by serially diluted C.albicans cells, by omitting WBC and RBC followed by enzymatic breaking of fungal cell wall and phenol – chlorophorm extraction and alcohol precipitation of DNA. A new primer pair was designed for PCR-amplification of a part of ribosomal RNA gene. The primer set was able to amplify all medically important Candida species. When PCR was performed for detection of purified DNA, the sensitivity of the method was about 1 picogram fungal DNA, whereas the sensitivity for detection of C.albicans blastospores inoculated in blood was as few as 10 cell per 0.1 ml of blood. This method could be sensitive and useful for early and rapid diagnosis of systemic Candida infections and to simultaneous detection and speciation of Candida species by PCR-RFLP method.

  20. Characterization of extracellular nucleotide metabolism in Candida albicans.

    Science.gov (United States)

    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.

  1. Detection of Candida albicans by mass spectrometric fingerprinting.

    Science.gov (United States)

    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 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. Short peptides allowing preferential detection of Candida albicans hyphae.

    Science.gov (United States)

    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.

  3. Disruption of the transcriptional regulator Cas5 results in enhanced killing of Candida albicans by Fluconazole.

    Science.gov (United States)

    Vasicek, Erin M; Berkow, Elizabeth L; Bruno, Vincent M; Mitchell, Aaron P; Wiederhold, Nathan P; Barker, Katherine S; Rogers, P David

    2014-11-01

    Azole antifungal agents such as fluconazole exhibit fungistatic activity against Candida albicans. Strategies to enhance azole antifungal activity would be therapeutically appealing. In an effort to identify transcriptional pathways that influence the killing activity of fluconazole, we sought to identify transcription factors (TFs) involved in this process. From a collection of C. albicans strains disrupted for genes encoding TFs (O. R. Homann, J. Dea, S. M. Noble, and A. D. Johnson, PLoS Genet. 5:e1000783, 2009, http://dx.doi.org/10.1371/journal.pgen.1000783), four strains exhibited marked reductions in minimum fungicidal concentration (MFCs) in both RPMI and yeast extract-peptone-dextrose (YPD) media. One of these genes, UPC2, was previously characterized with regard to its role in azole susceptibility. Of mutants representing the three remaining TF genes of interest, one (CAS5) was unable to recover from fluconazole exposure at concentrations as low as 2 μg/ml after 72 h in YPD medium. This mutant also showed reduced susceptibility and a clear zone of inhibition by Etest, was unable to grow on solid medium containing 10 μg/ml fluconazole, and exhibited increased susceptibility by time-kill analysis. CAS5 disruption in highly azole-resistant clinical isolates exhibiting multiple resistance mechanisms did not alter susceptibility. However, CAS5 disruption in strains with specific resistance mutations resulted in moderate reductions in MICs and MFCs. Genome-wide transcriptional analysis was performed in the presence of fluconazole and was consistent with the suggested role of CAS5 in cell wall organization while also suggesting a role in iron transport and homeostasis. These findings suggest that Cas5 regulates a transcriptional network that influences the response of C. albicans to fluconazole. Further delineation of this transcriptional network may identify targets for potential cotherapeutic strategies to enhance the activity of the azole class of antifungals.

  4. CaSfl1 plays a dual role in transcriptional regulation in Candida albicans

    Institute of Scientific and Technical Information of China (English)

    ZHANG TingTing; LI Di; LI WanJie; WANG Yue; SANG JianLi

    2008-01-01

    As a newly identified transcription factor in Candida albcians, CaSfl1 has been shown to be involved in cell flocculation and filamentation and in the negative regulation of several genes involved in hyphal growth. In this study, we constructed Casfl1△/△ mutants and confirmed that deletion of this gene in-deed affected cell flocculation and filamentation. In addition, by RT-PCR we found that while Casfl1 repressed the expression of several hypha-specific genes including HWP1, ECE1, ALS1, ALS3, and FL08, it strongly activated the expression of the heat-shock protein genes HSP30 and HSP90 under certain stress conditions. Therefore, we propose that CaSfl1 can act as both positive and negative regulators, thereby playing a dual role in transcriptional controls in Candida albicans.

  5. Lactobacillus acidophilus Probiotic Inhibits the Growth of Candida albicans

    Directory of Open Access Journals (Sweden)

    Sawitri D. Pertami

    2014-04-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Candida albicans is the most common organism causing oral candidiasis. Drug resistance to synthetic antifungal medication is becoming a problem in the treatment of oral candidiasis, especially in immunocompromised patients.Probiotic has been known for its health benefits. It produces lactic acid and bacteriocin that has antibacterial effect. Research focuses on antifungal effect of probiotic, escpecially for C. albicans is still needed. Objective: To determinethe inhibition effect of probiotic in the growth of C. albicans. Methods: Three concentrations of Lactobacillus acidophilus-containing probiotic (McFarland 6, 8, 10 were used to determine their inhibition effect on C. albicans (McFarland 0.5 growing in trypticase yeast-extract cystine (TYC agar. The inhibition effect of probiotic was determined by measuring the inhibition zone produced after 48 hours of culture. Difference in inhibition zone among experimental groups was analyzed using one-way ANOVA and LSD post-test. Results: Probiotic with McFarland 10 had the highest inhibition effect against C. albicans and the difference to other experimental groups was statistically significant (p<0.05. Conclusion: L. acidophilus probiotic has inhibition effect in the growth of C. albicans.DOI: 10.14693/jdi.v20i3.196

  6. Phylogeography of the Neotropical catfish Pimelodus albicans (Siluriformes: Pimelodidae from río de la Plata basin, South America, and conservation remarks

    Directory of Open Access Journals (Sweden)

    Julia Vergara

    Full Text Available Pimelodus albicans Valenciennes, 1840 (common name "moncholo" or "bagre blanco" is an endemic species of the family Pimelodidae in the río de la Plata basin. Phylogenetic approach based on cytochrome b sequences was performed to test the existence of a unique evolutionary lineage in P. albicans and to discriminate populations units or subpopulations related to a migration behavior of this taxon in the río de la Plata basin. This study included 34 samples of P. albicans of different collecting sites in the río de la Plata estuary and in the río Arrecifes belonging to the río Paraná basin. Among 614 base pairs in the cytochrome b sequence data set, 203 were variable and 120 were phylogenetically informative sites in P. albicans. A total of twenty haplotypes, nucleotide diversity (p = 0.032 and haplotype diversity = 0.941 were found. Tajima's test showed significant value D= -1.88 (p<0.05 rejecting the neutral mutation hypothesis for the P. albicans data set. All phylogenetic approaches showed that P. albicans included four monophyletic assemblages that were supported by high bootstrap and Bayesian posterior probability values. Minimum spanning network corroborated these groups for P. albicans haplotypes. High genetic structure was found in P. albicans by means of AMOVA analysis showing that the río Arrecifes samples constitute an isolated lineage. Moreover, the high value of genetic divergence (10% between the río de la Plata and the río Arrecifes populations could suggest that P. albicans may be conformed by a sibling species complex. On the other hand, a degree of genetic structuring was detected among different sites of the río de la Plata. A partial isolation of the 760 site may suggest that P. albicans could migrates to different tributaries for reproduction, generating different schools of haplotypes which could mix in the río de la Plata estuary. The high nucleotide diversity found in the 765 site and the existence of gene flow

  7. The novel Candida albicans transporter Dur31 Is a multi-stage pathogenicity factor.

    Directory of Open Access Journals (Sweden)

    François L Mayer

    Full Text Available Candida albicans is the most frequent cause of oral fungal infections. However, the exact pathogenicity mechanisms that this fungus employs are largely unknown and many of the genes expressed during oral infection are uncharacterized. In this study we sought to functionally characterize 12 previously unknown function genes associated with oral candidiasis. We generated homozygous knockout mutants for all 12 genes and analyzed their interaction with human oral epithelium in vitro. Eleven mutants caused significantly less epithelial damage and, of these, deletion of orf19.6656 (DUR31 elicited the strongest reduction in pathogenicity. Interestingly, DUR31 was not only involved in oral epithelial damage, but in multiple stages of candidiasis, including surviving attack by human neutrophils, endothelial damage and virulence in vivo. In silico analysis indicated that DUR31 encodes a sodium/substrate symporter with 13 transmembrane domains and no human homologue. We provide evidence that Dur31 transports histatin 5. This is one of the very first examples of microbial driven import of this highly cytotoxic antimicrobial peptide. Also, in contrast to wild type C. albicans, dur31Δ/Δ was unable to actively increase local environmental pH, suggesting that Dur31 lies in the extracellular alkalinization hyphal auto-induction pathway; and, indeed, DUR31 was required for morphogenesis. In agreement with this observation, dur31Δ/Δ was unable to assimilate the polyamine spermidine.

  8. Superoxide dismutases and glutaredoxins have a distinct role in the response of Candida albicans to oxidative stress generated by the chemical compounds menadione and diamide

    Directory of Open Access Journals (Sweden)

    Guilherme Maranhão Chaves

    2012-12-01

    Full Text Available To cope with oxidative stress, Candida albicans possesses several enzymes involved in a number of biological processes, including superoxide dismutases (Sods and glutaredoxins (Grxs. The resistance of C. albicans to reactive oxygen species is thought to act as a virulence factor. Genes such as SOD1 and GRX2, which encode for a Sod and Grx, respectively, in C. albicans are widely recognised to be important for pathogenesis. We generated a double mutant, Δgrx2/sod1, for both genes. This strain is very defective in hyphae formation and is susceptible to killing by neutrophils. When exposed to two compounds that generate reactive oxygen species, the double null mutant was susceptible to menadione and resistant to diamide. The reintegration of the SOD1 gene in the null mutant led to recovery in resistance to menadione, whereas reintegration of the GRX2 gene made the null mutant sensitive to diamide. Despite having two different roles in the responses to oxidative stress generated by chemical compounds, GRX2 and SOD1 are important for C. albicans pathogenesis because the double mutant Δgrx2/sod1 was very susceptible to neutrophil killing and was defective in hyphae formation in addition to having a lower virulence in an animal model of systemic infection.

  9. Candida albicans increases tumor cell adhesion to endothelial cells in vitro: intraspecific differences and importance of the mannose receptor.

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    Andoni Ramirez-Garcia

    Full Text Available The dimorphic fungus Candida albicans is able to trigger a cytokine-mediated pro-inflammatory response that increases tumor cell adhesion to hepatic endothelium and metastasis. To check the intraspecific differences in this effect, we used an in vitro murine model of hepatic response against C. albicans, which made clear that tumor cells adhered more to endothelium incubated with blastoconidia, both live and killed, than germ tubes. This finding was related to the higher carbohydrate/protein ratio found in blastoconidia. In fact, destruction of mannose ligand residues on the cell surface by metaperiodate treatment significantly reduced tumor cell adhesion induced. Moreover, we also noticed that the effect of clinical strains was greater than that of the reference one. This finding could not be explained by the carbohydrate/protein data, but to explain these differences between strains, we analyzed the expression level of ten genes (ADH1, APE3, IDH2, ENO1, FBA1, ILV5, PDI1, PGK1, QCR2 and TUF1 that code for the proteins identified previously in a mannoprotein-enriched pro-metastatic fraction of C. albicans. The results corroborated that their expression was higher in clinical strains than the reference one. To confirm the importance of the mannoprotein fraction, we also demonstrate that blocking the mannose receptor decreases the effect of C. albicans and its mannoproteins, inhibiting IL-18 synthesis and tumor cell adhesion increase by around 60%. These findings could be the first step towards a new treatment for solid organ cancers based on the role of the mannose receptor in C. albicans-induced tumor progression and metastasis.

  10. In vitro evaluation of antifungal activity of monolaurin against Candida albicans biofilms.

    Science.gov (United States)

    Seleem, Dalia; Chen, Emily; Benso, Bruna; Pardi, Vanessa; Murata, Ramiro M

    2016-01-01

    Monolaurin (also known as glycerol monolaurate) is a natural compound found in coconut oil and is known for its protective biological activities as an antimicrobial agent. The nature of oral candidiasis and the increased antifungal resistance demand the search for novel antifungal therapeutic agents. In this study, we examine the antifungal activity of monolaurin against Candida albicans biofilms (strain ATCC:SC5314/MYA2876) in vitro and investigate whether monolaurin can alter gene expression of host inflammatory cytokines, IL-1α and IL-1β. In a co-culture model, oral fibroblast cells were cultured simultaneously with C. albicans for 24 hrs followed by the exposure to treatments of monolaurin (3.9-2,500 µM), positive control fluconazole (32.2 µM), and vehicle control group (1% ethanol), which was a model used to evaluate the cytotoxicity of monolaurin on fibroblasts as well as to analyze morphological characteristics of biofilms through fluorescence microscopy. In addition, the co-culture model was used for RNA extraction of oral fibroblasts to assess gene expression of host inflammatory cytokines, using quantitative real-time PCR. Our results showed the MIC and MFC of monolaurin were in the range 62.5-125 µM and 125-250 µM, respectively. Biofilm antifungal assay showed significant reduction in Log (CFU/ml) of biofilms treated with 1,250 and 2,500 µM of 1-monolaurin when compared to the control groups . There was also a significant down-regulation of IL-1α and IL-1β in the co-culture treated with monolaurin. It can be concluded that monolaurin has a potential antifungal activity against C. albicans and can modulate the pro-inflammatory response of the host.

  11. In vitro evaluation of antifungal activity of monolaurin against Candida albicans biofilms

    Directory of Open Access Journals (Sweden)

    Dalia Seleem

    2016-06-01

    Full Text Available Monolaurin (also known as glycerol monolaurate is a natural compound found in coconut oil and is known for its protective biological activities as an antimicrobial agent. The nature of oral candidiasis and the increased antifungal resistance demand the search for novel antifungal therapeutic agents. In this study, we examine the antifungal activity of monolaurin against Candida albicans biofilms (strain ATCC:SC5314/MYA2876 in vitro and investigate whether monolaurin can alter gene expression of host inflammatory cytokines, IL-1α and IL-1β. In a co-culture model, oral fibroblast cells were cultured simultaneously with C. albicans for 24 hrs followed by the exposure to treatments of monolaurin (3.9–2,500 µM, positive control fluconazole (32.2 µM, and vehicle control group (1% ethanol, which was a model used to evaluate the cytotoxicity of monolaurin on fibroblasts as well as to analyze morphological characteristics of biofilms through fluorescence microscopy. In addition, the co-culture model was used for RNA extraction of oral fibroblasts to assess gene expression of host inflammatory cytokines, using quantitative real-time PCR. Our results showed the MIC and MFC of monolaurin were in the range 62.5–125 µM and 125–250 µM, respectively. Biofilm antifungal assay showed significant reduction in Log (CFU/ml of biofilms treated with 1,250 and 2,500 µM of 1-monolaurin when compared to the control groups . There was also a significant down-regulation of IL-1α and IL-1β in the co-culture treated with monolaurin. It can be concluded that monolaurin has a potential antifungal activity against C. albicans and can modulate the pro-inflammatory response of the host.

  12. In vitro evaluation of antifungal activity of monolaurin against Candida albicans biofilms

    Science.gov (United States)

    Benso, Bruna; Pardi, Vanessa

    2016-01-01

    Monolaurin (also known as glycerol monolaurate) is a natural compound found in coconut oil and is known for its protective biological activities as an antimicrobial agent. The nature of oral candidiasis and the increased antifungal resistance demand the search for novel antifungal therapeutic agents. In this study, we examine the antifungal activity of monolaurin against Candida albicans biofilms (strain ATCC:SC5314/MYA2876) in vitro and investigate whether monolaurin can alter gene expression of host inflammatory cytokines, IL-1α and IL-1β. In a co-culture model, oral fibroblast cells were cultured simultaneously with C. albicans for 24 hrs followed by the exposure to treatments of monolaurin (3.9–2,500 µM), positive control fluconazole (32.2 µM), and vehicle control group (1% ethanol), which was a model used to evaluate the cytotoxicity of monolaurin on fibroblasts as well as to analyze morphological characteristics of biofilms through fluorescence microscopy. In addition, the co-culture model was used for RNA extraction of oral fibroblasts to assess gene expression of host inflammatory cytokines, using quantitative real-time PCR. Our results showed the MIC and MFC of monolaurin were in the range 62.5–125 µM and 125–250 µM, respectively. Biofilm antifungal assay showed significant reduction in Log (CFU/ml) of biofilms treated with 1,250 and 2,500 µM of 1-monolaurin when compared to the control groups . There was also a significant down-regulation of IL-1α and IL-1β in the co-culture treated with monolaurin. It can be concluded that monolaurin has a potential antifungal activity against C. albicans and can modulate the pro-inflammatory response of the host. PMID:27366648

  13. A novel role of the ferric reductase Cfl1 in cell wall integrity, mitochondrial function, and invasion to host cells in Candida albicans.

    Science.gov (United States)

    Yu, Qilin; Dong, Yijie; Xu, Ning; Qian, Kefan; Chen, Yulu; Zhang, Biao; Xing, Laijun; Li, Mingchun

    2014-11-01

    Candida albicans is an important opportunistic pathogen, causing both superficial mucosal infections and life-threatening systemic diseases. Iron acquisition is an important factor for pathogen-host interaction and also a significant element for the pathogenicity of this organism. Ferric reductases, which convert ferric iron into ferrous iron, are important components of the high-affinity iron uptake system. Sequence analyses have identified at least 17 putative ferric reductase genes in C. albicans genome. CFL1 was the first ferric reductase identified in C. albicans. However, little is known about its roles in C. albicans physiology and pathogenicity. In this study, we found that disruption of CFL1 led to hypersensitivity to chemical and physical cell wall stresses, activation of the cell wall integrity (CWI) pathway, abnormal cell wall composition, and enhanced secretion, indicating a defect in CWI in this mutant. Moreover, this mutant showed abnormal mitochondrial activity and morphology, suggesting a link between ferric reductases and mitochondrial function. In addition, this mutant displayed decreased ability of adhesion to both the polystyrene microplates and buccal epithelial cells and invasion of host epithelial cells. These findings revealed a novel role of C. albicans Cfl1 in maintenance of CWI, mitochondrial function, and interaction between this pathogen and the host.

  14. Daya hambat xylitol dan nistation terhadap pertumbuhan Candida albicans (in vitro (Inhibition effect of xylitol and nistatin combination on Candida albicans growth (in vitro

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    Sarah Kartimah Djajusman

    2014-09-01

    Full Text Available Background: The growth of Candida albicans can be controlled by using antifungal such as nystatin. These days we found that using antifungal is not enough to control Candida albicans, we also have to control the intake of sugar by using xylitol. Purpose: Purpose of the study was to determine the optimal inhibitory concentration of xylitol-nystatin in the Candida albicans growth. Methods: This was an in-vitro study using an antimicrobial test of serial dilution with xylitol-nystatin and sucrose–nystatin consentration of 1%, 3%, 5%, 7%, 9%, and 10%.Growth inhibition of C. albicans was determined by the inhibition zone of xylitol + nystatin on C. albicans culture media (in vitro Results: The result of study was the inhibitory consentration of xylitol-nystatin to inhibit Candida albicans growth was 3%-10%. Conclusion: The study showed that combination of xylitol and nystation could inhibit the growth of Candida albicans.Latar belakang: Pertumbuhan Candida albicans dapat dikontrol dengan menggunakan antijamur seperti nistatin. Penggunakan antijamur saja tidak cukup untuk mengontrol Candida albicans, namun perlu pula mengontrol asupan gula dengan menggunakan xylitol. Tujuan: Tujuan dari penelitian ini adalah untuk menentukan konsentrasi hambat optimal xylitol-nistatin dalam pertumbuhan Candida albicans. Metode: Penelitian ini merupakan penelitian in vitro menggunakan uji antimikroba pengenceran serial dengan xylitol-nistatin dan nystatin-sukrosa konsentrasi 1%, 3 %, 5 %, 7%, 9%, dan 10%. Daya hambat pertumbuhan C. albicans diukur dari zona hambat xylitol + nistatin pada media kultur C. albicans (in vitro Hasil: Konsentrasi penghambatan xylitol-nistatin untuk menghambat pertumbuhan Candida albicans adalah 3-10%. Simpulan: Hasil penelitian menunjukkan bahwa kombinasi xylitol dan nystation bisa menghambat pertumbuhan Candida albicans.

  15. Cellular responses of Candida albicans to phagocytosis and the extracellular activities of neutrophils are critical to counteract carbohydrate starvation, oxidative and nitrosative stress.

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    Miramón, Pedro; Dunker, Christine; Windecker, Hanna; Bohovych, Iryna M; Brown, Alistair J P; Kurzai, Oliver; Hube, Bernhard

    2012-01-01

    Neutrophils are key players during Candida albicans infection. However, the relative contributions of neutrophil activities to fungal clearance and the relative importance of the fungal responses that counteract these activities remain unclear. We studied the contributions of the intra- and extracellular antifungal activities of human neutrophils using diagnostic Green Fluorescent Protein (GFP)-marked C. albicans strains. We found that a carbohydrate starvation response, as indicated by up-regulation of glyoxylate cycle genes, was only induced upon phagocytosis of the fungus. Similarly, the nitrosative stress response was only observed in internalised fungal cells. In contrast, the response to oxidative stress was observed in both phagocytosed and non-phagocytosed fungal cells, indicating that oxidative stress is imposed both intra- and extracellularly. We assessed the contributions of carbohydrate starvation, oxidative and nitrosative stress as antifungal activities by analysing the resistance to neutrophil killing of C. albicans mutants lacking key glyoxylate cycle, oxidative and nitrosative stress genes. We found that the glyoxylate cycle plays a crucial role in fungal resistance against neutrophils. The inability to respond to oxidative stress (in cells lacking superoxide dismutase 5 or glutathione reductase 2) renders C. albicans susceptible to neutrophil killing, due to the accumulation of reactive oxygen species (ROS). We also show that neutrophil-derived nitric oxide is crucial for the killing of C. albicans: a yhb1Δ/Δ mutant, unable to detoxify NO•, was more susceptible to neutrophils, and this phenotype was rescued by the nitric oxide scavenger carboxy-PTIO. The stress responses of C. albicans to neutrophils are partially regulated via the stress regulator Hog1 since a hog1Δ/Δ mutant was clearly less resistant to neutrophils and unable to respond properly to neutrophil-derived attack. Our data indicate that an appropriate fungal response to all

  16. Activation and alliance of regulatory pathways in C. albicans during mammalian infection.

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    Wenjie Xu

    2015-02-01

    Full Text Available Gene expression dynamics have provided foundational insight into almost all biological processes. Here, we analyze expression of environmentally responsive genes and transcription factor genes to infer signals and pathways that drive pathogen gene regulation during invasive Candida albicans infection of a mammalian host. Environmentally responsive gene expression shows that there are early and late phases of infection. The early phase includes induction of zinc and iron limitation genes, genes that respond to transcription factor Rim101, and genes characteristic of invasive hyphal cells. The late phase includes responses related to phagocytosis by macrophages. Transcription factor gene expression also reflects early and late phases. Transcription factor genes that are required for virulence or proliferation in vivo are enriched among highly expressed transcription factor genes. Mutants defective in six transcription factor genes, three previously studied in detail (Rim101, Efg1, Zap1 and three less extensively studied (Rob1, Rpn4, Sut1, are profiled during infection. Most of these mutants have distinct gene expression profiles during infection as compared to in vitro growth. Infection profiles suggest that Sut1 acts in the same pathway as Zap1, and we verify that functional relationship with the finding that overexpression of either ZAP1 or the Zap1-dependent zinc transporter gene ZRT2 restores pathogenicity to a sut1 mutant. Perturbation with the cell wall inhibitor caspofungin also has distinct gene expression impact in vivo and in vitro. Unexpectedly, caspofungin induces many of the same genes that are repressed early during infection, a phenomenon that we suggest may contribute to drug efficacy. The pathogen response circuitry is tailored uniquely during infection, with many relevant regulatory relationships that are not evident during growth in vitro. Our findings support the principle that virulence is a property that is manifested only in

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

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

    2017-01-01

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

  18. The role of Bgl2p in the transition to filamentous cells during biofilm formation by Candida albicans.

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    Chen, Xinyue; Zhang, Ruoyu; Takada, Ayako; Iwatani, Shun; Oka, Chiemi; Kitamoto, Toshitaka; Kajiwara, Susumu

    2017-02-01

    The fungal pathogen Candida albicans undergoes a transition from yeast cells to filamentous cells that is related to its pathogenicity. The complex multicellular processes involved in biofilm formation by this fungus also include this transition. In this work, we investigated the morphological role of the Bgl2 protein (Bgl2p) in the transition to filamentous cells during biofilm formation by C. albicans. Bgl2p has been identified as a β-1, 3-glucosyltransferase, and transcription of the CaBGL2 gene is upregulated during biofilm formation. We used scanning electron microscopy to observe the microstructure of a bgl2 null mutant during biofilm formation and found a delay in the transition to filamentous cells in the premature phase (24 hours) of biofilm formation. Deletion of the CaBGL2 gene led to a decrease in the expression of CPH2 and TEC1, which encode transcription factors required for the transition to the filamentous form. These findings indicate that Bgl2p plays a role in the transition to filamentous cells during biofilm formation by C. albicans.

  19. Elderly nutritional status effection salivary anticandidal capacity against Candida albicans

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    Ria Puspitawati

    2011-06-01

    Full Text Available Background: Elderly often suffer malnutrition and oral candidiasis. Candida albicans (C. albicans which is the most prominent cause of oral candidiasis, is one of commensal oral micro-flora. Nutritional status affect the characteristic of saliva. Saliva is the regulator in the development of C. albicans from comensal into pathogen. Purpose: The purpose of this study was to determining the correlation between elderly nutritional status with salivary total protein and its activity in inhibiting C. albicans growth and biofilm formation. Methods: Using mini nutritional assessment 30 elderly were classified into normal and malnutrition groups. Total protein of unstimulated saliva was measured using Bradford protein assay. The colony forming unit (CFU of C. albicans was counted on 72 hours on SDA cultures without (control or with 2 hour saliva exposure. Biofilm formation was analyzed from the optical density of 10–5 C. albicans suspension without saliva exposure (control or with exposure of 10.000 μg/ml saliva and incubated in 37° C for 2 days. The suspension was put into 96 well plates, stained with crystal-violet dye, and analyzed using microplate reader. Differences between groups were analyzed using independent t-test or Kruskall-Wallis. Correlation between variables was analyzed using Spearman test. Results: Salivary total protein of normal elderly (1.113.5 ± 1.1143.3 was higher than those of malnutrition (613.6 ± 253.6 but not statistically significant (p > 0.05. The CFU of C. albicans exposed to saliva of normal samples (2.060 cfu/ml was significantly lower than control (24.100 cfu/ml and those exposed to malnutrition saliva (5.513.3 cfu/ml. C. albicans biofilm formation is highest in controls (0.177, lower in those exposed to malnourished saliva (0.151 and lowest in those exposed to saliva of good nourished elderly (0.133. Conclusion: Although does not cause significant decrease of salivary total protein, malnutrition in elderly results

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

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

    2016-11-01

    Oral biofilms comprise of extracellular polysaccharides and polymicrobial microorganisms. The objective of this study was to determine the effect of polymicrobial interactions of Candida albicans, Actinomyces naeslundii, and Streptococcus mutans on biofilm formation with the hypotheses that biofilm biomass and metabolic activity are both C. albicans strain and growth medium dependent. To study monospecific biofilms, C. albicans, A. naeslundii, and S. mutans were inoculated into artificial saliva medium (ASM) and RPMI-1640 in separate vials, whereas to study polymicrobial biofilm formation, the inoculum containing microorganisms was prepared in the same vial prior inoculation into a 96-well plate followed by 72 hours incubation. Finally, biofilm biomass and metabolic activity were measured using crystal violet and XTT assays, respectively. Our results showed variability of monospecies and polymicrobial biofilm biomass between C. albicans strains and growth medium. Based on cut-offs, out of 32, seven RPMI-grown biofilms had high biofilm biomass (HBB), whereas, in ASM-grown biofilms, 14 out of 32 were HBB. Of the 32 biofilms grown in RPMI-1640, 21 were high metabolic activity (HMA), whereas in ASM, there was no biofilm had HMA. Significant differences were observed between ASM and RPMI-grown biofilms with respect to metabolic activity (P biofilm biomass and metabolic activity were both C. albicans strain and growth medium dependent.

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

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    Apurva K Pathak

    2012-02-01

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

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

    Science.gov (United States)

    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 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.

  3. Interleukin 17-Mediated Host Defense against Candida albicans

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    Florian Sparber

    2015-08-01

    Full Text Available Candida albicans is part of the normal microbiota in most healthy individuals. However, it can cause opportunistic infections if host defenses are breached, with symptoms ranging from superficial lesions to severe systemic disease. The study of rare congenital defects in patients with chronic mucocutaneous candidiasis led to the identification of interleukin-17 (IL-17 as a key factor in host defense against mucosal fungal infection. Experimental infections in mice confirmed the critical role of IL-17 in mucocutaneous immunity against C. albicans. Research on mouse models has also contributed importantly to our current understanding of the regulation of IL-17 production by different cellular sources and its effector functions in distinct tissues. In this review, we highlight recent findings on IL-17-mediated immunity against C. albicans in mouse and man.

  4. Oral candidiasis-adhesion of non-albicans Candida species

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    Bokor-Bratić Marija B.

    2008-01-01

    Full Text Available Oral candidiasis is an opportunistic infection caused primarily by Candida albicans. However, in recent years, species of non-albicans Candida have been implicated more frequently in mucosal infection. Candida species usually reside as commensal organisms and are part of normal oral microflora. Determining exactly how transformation from commensal to pathogen takes place and how it can be prevented is continuous challenge for clinical doctors. Candidal adherence to mucosal surfaces is considered as a critical initial step in the pathogenesis of oral candidiasis. Acrylic dentures, acting as reservoirs, play an important role in increasing the risk from Candida colonisation. Thus, this review discusses what is currently known about the adhesion of non-albicans Candida species of oral origin to buccal epithelial cells and denture acrylics.

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

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    Anja Wartenberg

    2014-12-01

    Full Text Available 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.

  6. Cross-feeding and interkingdom communication in dual-species biofilms of Streptococcus mutans and Candida albicans.

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    Sztajer, Helena; Szafranski, Szymon P; Tomasch, Jürgen; Reck, Michael; Nimtz, Manfred; Rohde, Manfred; Wagner-Döbler, Irene

    2014-11-01

    Polymicrobial biofilms are of large medical importance, but relatively little is known about the role of interspecies interactions for their physiology and virulence. Here, we studied two human pathogens co-occuring in the oral cavity, the opportunistic fungus Candida albicans and the caries-promoting bacterium Streptococcus mutans. Dual-species biofilms reached higher biomass and cell numbers than mono-species biofilms, and the production of extracellular polymeric substances (EPSs) by S. mutans was strongly suppressed, which was confirmed by scanning electron microscopy, gas chromatography-mass spectrometry and transcriptome analysis. To detect interkingdom communication, C. albicans was co-cultivated with a strain of S. mutans carrying a transcriptional fusion between a green fluorescent protein-encoding gene and the promoter for sigX, the alternative sigma factor of S. mutans, which is induced by quorum sensing signals. Strong induction of sigX was observed in dual-species biofilms, but not in single-species biofilms. Conditioned media from mixed biofilms but not from C. albicans or S. mutans cultivated alone activated sigX in the reporter strain. Deletion of comS encoding the synthesis of the sigX-inducing peptide precursor abolished this activity, whereas deletion of comC encoding the competence-stimulating peptide precursor had no effect. Transcriptome analysis of S. mutans confirmed induction of comS, sigX, bacteriocins and the downstream late competence genes, including fratricins, in dual-species biofilms. We show here for the first time the stimulation of the complete quorum sensing system of S. mutans by a species from another kingdom, namely the fungus C. albicans, resulting in fundamentally changed virulence properties of the caries pathogen.

  7. Radiolabel release microassay for phagocytic killing of Candida albicans

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    Bistoni, F.; Baccarini, M.; Blasi, E.; Marconi, P. (Perugia Univ. (Italy). Inst. of Microbiology); Puccetti, P. (Perugia Univ. (Italy). Inst. of Pharmacology)

    1982-08-13

    The chromium-51 release technique for quantifying intracellular killing of radiolabelled Candida albicans particles was exploited in a microassay in which murine and human phagocytes acted as effectors under peculiarly simple conditions. At appropriate effector: target ratios and with a 4 h incubation, up to 50% specific chromium release could be detected in the supernatant with no need for opsonization or lysis of phagocytes. This simple microassay permits easy-to-perform, simultaneous testing of a variety of different phagocytes even if only available in limited amounts, and provides an objective measurement of intracellular killing of Candida albicans.

  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.

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    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. Roles of Candida albicans Gat2, a GATA-type zinc finger transcription factor, in biofilm formation, filamentous growth and virulence.

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    Du, Han; Guan, Guobo; Xie, Jing; Sun, Yuan; Tong, Yaojun; Zhang, Lixin; Huang, Guanghua

    2012-01-01

    Candida albicans is the most common human fungal pathogen, causing not only superficial infections, but also life-threatening systemic disease. C. albicans can grow in several morphological forms including unicellular yeast-form, elongated hyphae and pseudohyphae. In certain natural environments, C. albicans also exists as biofilms, which are structured and surface-attached microbial communities. Transcription factors play a critical role in morphogenesis and biofilm development. In this study, we identified four adhesion-promoting transcription factors (Tec1, Cph1, Ume6 and Gat2) by screening a transcription factor overexpression library. Sequence analysis indicates that Gat2 is a GATA-type zinc finger transcription factor. Here we showed that the gat2/gat2 mutant failed to form biofilms on the plastic and silicone surfaces. Overexpression of GAT2 gene promoted filamentous and invasive growth on agar containing Lee's medium, while deletion of this gene had an opposite effect. However, inactivation of Gat2 had no obvious effect on N-acetyl-glucosamine (GlcNAc) induced hyphal development. In a mouse model of systemic infection, the gat2/gat2 mutant showed strongly attenuated virulence. Our results suggest that Gat2 plays a critical role in C. albicans biofilm formation, filamentous growth and virulence.

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

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    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.

  11. Synergistic Effect of Fluconazole and Calcium Channel Blockers against Resistant Candida albicans.

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    Liu, Shuyuan; Yue, Longtao; Gu, Wenrui; Li, Xiuyun; Zhang, Liuping; Sun, Shujuan

    2016-01-01

    Candidiasis has increased significantly recently that threatens patients with low immunity. However, the number of antifungal drugs on the market is limited in comparison to the number of available antibacterial drugs. This fact, coupled with the increased frequency of fungal resistance, makes it necessary to develop new therapeutic strategies. Combination drug therapy is one of the most widely used and effective strategy to alleviate this problem. In this paper, we were aimed to evaluate the combined antifungal effects of four CCBs (calcium channel blockers), amlodipine (AML), nifedipine (NIF), benidipine (BEN) and flunarizine (FNZ) with fluconazole against C. albicans by checkerboard and time-killing method. In addition, we determined gene (CCH1, MID1, CNA1, CNB1, YVC1, CDR1, CDR2 and MDR1) expression by quantitative PCR and investigated the efflux pump activity of resistant candida albicans by rhodamine 6G assay to reveal the potential mechanisms. Finally, we concluded that there was a synergy when fluconazole combined with the four tested CCBs against resistant strains, with fractional inhibitory concentration index (FICI) fluconazole plus amlodipine caused down-regulating of CNA1, CNB1 (encoding calcineurin) and YVC1 (encoding calcium channel protein in vacuole membrane).

  12. White cells facilitate opposite- and same-sex mating of opaque cells in Candida albicans.

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    Li Tao

    2014-10-01

    Full Text Available Modes of sexual reproduction in eukaryotic organisms are extremely diverse. The human fungal pathogen Candida albicans undergoes a phenotypic switch from the white to the opaque phase in order to become mating-competent. In this study, we report that functionally- and morphologically-differentiated white and opaque cells show a coordinated behavior during mating. Although white cells are mating-incompetent, they can produce sexual pheromones when treated with pheromones of the opposite mating type or by physically interacting with opaque cells of the opposite mating type. In a co-culture system, pheromones released by white cells induce opaque cells to form mating projections, and facilitate both opposite- and same-sex mating of opaque cells. Deletion of genes encoding the pheromone precursor proteins and inactivation of the pheromone response signaling pathway (Ste2-MAPK-Cph1 impair the promoting role of white cells (MTLa in the sexual mating of opaque cells. White and opaque cells communicate via a paracrine pheromone signaling system, creating an environment conducive to sexual mating. This coordination between the two different cell types may be a trade-off strategy between sexual and asexual lifestyles in C. albicans.

  13. Synergistic Effect of Fluconazole and Calcium Channel Blockers against Resistant Candida albicans.

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    Shuyuan Liu

    Full Text Available Candidiasis has increased significantly recently that threatens patients with low immunity. However, the number of antifungal drugs on the market is limited in comparison to the number of available antibacterial drugs. This fact, coupled with the increased frequency of fungal resistance, makes it necessary to develop new therapeutic strategies. Combination drug therapy is one of the most widely used and effective strategy to alleviate this problem. In this paper, we were aimed to evaluate the combined antifungal effects of four CCBs (calcium channel blockers, amlodipine (AML, nifedipine (NIF, benidipine (BEN and flunarizine (FNZ with fluconazole against C. albicans by checkerboard and time-killing method. In addition, we determined gene (CCH1, MID1, CNA1, CNB1, YVC1, CDR1, CDR2 and MDR1 expression by quantitative PCR and investigated the efflux pump activity of resistant candida albicans by rhodamine 6G assay to reveal the potential mechanisms. Finally, we concluded that there was a synergy when fluconazole combined with the four tested CCBs against resistant strains, with fractional inhibitory concentration index (FICI <0.5, but no interaction against sensitive strains (FICI = 0.56 ~ 2. The mechanism studies revealed that fluconazole plus amlodipine caused down-regulating of CNA1, CNB1 (encoding calcineurin and YVC1 (encoding calcium channel protein in vacuole membrane.

  14. Immune response to Candida albicans is preserved despite defect in O-mannosylation of secretory proteins.

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    Corbucci, Cristina; Cenci, Elio; Skrzypek, Franck; Gabrielli, Elena; Mosci, Paolo; Ernst, Joachim F; Bistoni, Francesco; Vecchiarelli, Anna

    2007-12-01

    The PMT gene family in Candida albicans encodes five isoforms of the protein mannosyltransferases that initiate O-mannosylation of secretory proteins. Mutations at the Pmt level have been associated with differences in pathogenicity, e.g. in contrast to pmt5/pmt5, pmt2/PMT2 mutants showed poor virulence. Our objective was to determine whether these differences were related to the capacity of pmt2/PMT2 and pmt5/pmt5 to (i) express differences in selected virulence factors, and (ii) stimulate the natural immune system. The results show that pmt mutants (i) form hyphae in serum, (ii) show defective production of proteases but not of phospholipases with respect to the parental strain, (iii) undergo mycelial transition in the kidneys of hematogenously infected animals, (iv) are phagocytosed and killed by macrophages similar to the parental strain, although neutrophils are unable to destroy pmt5/pmt5, (v) engage TLR4 and stimulate MyD88 leading to NF-kappaB activation, and (vi) stimulate cytokine production by macrophages. Collectively our findings suggest that the defect in protein O-mannosylation in C. albicans cause attenuation of the virulence although the antigenic factors that retain the capacity to stimulate an efficient immune response are preserved.

  15. Virulence of the fungal pathogen Candida albicans requires the five isoforms of protein mannosyltransferases.

    Science.gov (United States)

    Rouabhia, Mahmoud; Schaller, Martin; Corbucci, Cristina; Vecchiarelli, Anna; Prill, Stephan K-H; Giasson, Luc; Ernst, Joachim F

    2005-08-01

    The PMT gene family in Candida albicans encodes five isoforms of protein mannosyltransferases (Pmt proteins Pmt1p, Pmt2p, Pmt4p, Pmt5p, and Pmt6p) that initiate O mannosylation of secretory proteins. We compared virulence characteristics of pmt mutants in two complex, three-dimensional models of localized candidiasis, using reconstituted human epithelium (RHE) and engineered human oral mucosa (EHOM); in addition, mutants were tested in a mouse model of hematogenously disseminated candidiasis (HDC). All pmt mutants showed attenuated virulence in the HDC model and at least one model of localized candidiasis. The pmt5 mutant, which lacks in vitro growth phenotypes, was less virulent in the EHOM and HDC assays but had no consistent phenotype in the RHE assay. In contrast, the pmt4 and pmt6 mutants were less virulent in the RHE and HDC assays but not in the EHOM assay. The results stress the contribution of all Pmt isoforms to the virulence of C. albicans and suggest that the importance of individual Pmt isoforms may differ in specific host niches. We propose that Pmt proteins may be suitable targets for future novel classes of antifungal agents.

  16. Isolation and Selection of Anti-Candida albicans Metabolites Producing Lactic Acid Bacteria from Various Sources

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    Tanes SUNGSRI

    2015-02-01

    Full Text Available Five hundred and fifty-two of lactic acid bacteria (LAB have been isolated and screened from fermented foods, natural sources and dairy effluents on De Mann Rogosa Sharpe (MRS agar. Fifty-one isolates, in the percentile of 9.24, produced the secondary metabolites that could inhibit the growth of Candida albicans BCC6120 by using dual culture overlay assay. The culture broth of LAB, moreover, showed anti-C. albicans activity in acidic condition at pH range of 3.0-5.0 by using agar well diffusion method. Interestingly, the isolate L-47-2 showed much more colonization surrounding the surface of sterile toothpick and test tube when growing in MRS broth. The identification of isolate L-47-2 by morphological and biochemical characteristics using API 50 CHL Test Kit and further confirmed by 16S rRNA gene sequence analysis revealed that isolate L47-2 was similar to Lactobacillus paracasei with 99% nucleotide identity.    

  17. Broth dilution testing of Candida albicans susceptibility to ketoconazole.

    OpenAIRE

    Hughes, C E; Bennett, R L; Beggs, W H

    1987-01-01

    We performed a detailed investigation of the kinetics of ketoconazole activity in the setting of broth dilution testing of Candida albicans susceptibility. Turbidimetric readings reflected parallel quantitative colony counts. The method of endpoint determination markedly affected the results. Determinations of 50% inhibitory concentrations clearly separated the ketoconazole-resistant strains from the susceptible strains.

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

    Science.gov (United States)

    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.

  19. Hyphal content determines the compression strength of Candida albicans biofilms

    NARCIS (Netherlands)

    Paramonova, Ekaterina; Krom, Bastiaan P.; van der Mei, Henny C.; Busscher, Henk J.; Sharma, Prashant K.

    2009-01-01

    Candida albicans is the most frequently isolated human fungal pathogen among species causing biofilm-related clinical infections. Mechanical properties of Candida biofilms have hitherto been given no attention, despite the fact that mechanical properties are important for selection of treatment or d

  20. Antimicrobial Activity of Five Medicinal Plants on Candida Albicans

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    Fatemeh Masomi

    2016-10-01

    Full Text Available Background: In recent years, drug resistance to human pathogenic fungi has been increased. Medicinal plants are one way to overcome antibiotic resistance. The aim of this study was to evaluate the antifungal and inhibitory activity of five medicinal plants on the growth of Candida albicans. Methods: This study was done in the Microbiology Lab of Shahid Bahonar University of Kerman, Iran in 2015. Five medicinal plants include: Trachyspermum ammi (seed, Teucrium polium (leaf, Piper nigrum (seed, Pistachia vera (skin, Camelia sinensis (leaf were collected. Collected plant materials were extracted by ethanol and methanol solvent with maceration method. Antifungal activity of the ethanolic and methanolic extracts was evaluated by paper disc diffusion and agar well diffusion methods. Besides, MIC and MBC of each extract was determined. Results: All plant extracts had sufficient inhibitory effect against C. albicans but the extracts of P. vera had the best inhibitory effect on C. albicans (ZOI: 40 mm. The lowest antifungal effect between these five plants related to Piper nigrum (ZOI: 13 mm. Besides, the P. vera extracts had the best MIC and MBC values (6.25 and 12.5 mg/ml. Conclusion: This study strongly evidence the maximum antimicrobial activity of medicinal plants against C. albicans that this inhibitory effect varies with the different solvent-extract form. A more comprehensive study need to identify the effective compounds that have these antifungal properties.

  1. Al-2 of Aggregatibacter actinomycetemcomitans inhibits Candida albicans biofilm formation

    NARCIS (Netherlands)

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

    2014-01-01

    Aggregatibacter actinomycetemcomitans, a Gram-negative bacterium, and Candida albicans, a polymorphic fungus, are both commensals of the oral cavity but both are opportunistic pathogens that can cause oral diseases. A. actinomycetemcomitans produces a quorum-sensing molecule called autoinducer-2 (Al

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

    Science.gov (United States)

    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.

  3. Host defence against disseminated and invasive Candida albicans infections

    NARCIS (Netherlands)

    Vonk, Alouise Gabrielle

    2004-01-01

    The yeast Candida albicans is the primary etiologic agent of disseminated and invasive candidiasis. The incidence of disseminated and invasive candidiasis has paralleled the use of modern medical procedures that adversely affect the immune system, and highlights the difficulty of treating disseminat

  4. PERTUMBUHAN CANDIDA ALBICANS PADA PERMUKAAN POLIESTER EBP-2421

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    Widowati Siswomihardjo

    2015-08-01

    Full Text Available Acrylic resin has been the only polymeric material for denture base for many years. One of the requirements for an ideal polymeric denture base material. It should be resistant to bacterial growth. The growth of Candida albicans on the surface of dentures is a concern for many denture wearers. This organism often is associated with denture stomatitis. A preliminary study showed polyester EBP-2421, a polymeric material for statues can also be manipulated to denture base. This research examined the growth of Candida albicans on the surface of EBP-2421. Research was carried out on strips of polyester EBP-2421 and Selton acrylic resin. Strips were contaminated with Candida albicans for 24 hours. Examinations on polyester EBP-2421 and acrylic resin immersed in saliva significantly differ from the not immersed strips (p<0,05. The lowest frequency were Candida albicans adhered on stripes of polyester EBP-2421 immersed in saliva. This result related with the fact that polyester EBP-2421 has smoother surface topography than acrylic resin.

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

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    Fikadu G Tafesse

    2015-10-01

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

  6. HIV aspartyl protease inhibitors as promising compounds against Candida albicans

    Institute of Scientific and Technical Information of China (English)

    André; Luis; Souza; dos; Santos

    2010-01-01

    Cells of Candida albicans(C.albicans) can invade humans and may lead to mucosal and skin infections or to deep-seated my coses of almost all inner organs,especially in immunocompromised patients.In this context,both the host immune status and the ability of C.albicans to modulate the expression of its virulence factors are relevant aspects that drive the candidal susceptibility or resistance;in this last case,culminating in the establishment of successful infection knownas candidiasis.C.albicans possesses a potent arma-mentarium consisting of several virulence moleculesthat help the fungal cells to escape of the host immuneresponses.There is no doubt that the secretion of aspartyl-type proteases,designated as Saps,are one of the major virulence attributes produced by C.albicans cells,since these hydrolytic enzymes participate in a wide range of fungal physiological processes as well as in different facets of the fungal-host interactions.For these reasons,Saps clearly hold promise as new potential drug targets.Corroborating this hypothesis,the introduction of new anti-human immunodeficiency virus drugs of the as party l protease inhibitor-type(HIV PIs) have emerged as new agents for the inhibition of Saps.The introduction of HIV PIs has revolutionized the treatment of HIV disease,reducing opportunistic infections,especially candidiasis.The attenuation of candidal infections in HIV-infected individuals might not solely have resulted from improved immunological status,but also as a result of direct inhibition of C.albicans Saps.In this article,we review updates on the beneficial effects of HIV PIs against the human fungal pathogen C.albicans,focusing on the effects of these compounds on Sap activity,growth behavior,morphological architecture,cellular differentiation,fungal adhesion to animal cells and abiotic materials,modulation of virulence factors,experimental candidiasis infection,and their synergistic actions with classical antifungal agents.

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

    Science.gov (United States)

    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.

  8. Comparative molecular dynamics studies of heterozygous open reading frames of DNA polymerase eta (η) in pathogenic yeast Candida albicans

    Science.gov (United States)

    Satpati, Suresh; Manohar, Kodavati; Acharya, Narottam; Dixit, Anshuman

    2017-01-01

    Genomic instability in Candida albicans is believed to play a crucial role in fungal pathogenesis. DNA polymerases contribute significantly to stability of any genome. Although Candida Genome database predicts presence of S. cerevisiae DNA polymerase orthologs; functional and structural characterizations of Candida DNA polymerases are still unexplored. DNA polymerase eta (Polη) is unique as it promotes efficient bypass of cyclobutane pyrimidine dimers. Interestingly, C. albicans is heterozygous in carrying two Polη genes and the nucleotide substitutions were found only in the ORFs. As allelic differences often result in functional differences of the encoded proteins, comparative analyses of structural models and molecular dynamic simulations were performed to characterize these orthologs of DNA Polη. Overall structures of both the ORFs remain conserved except subtle differences in the palm and PAD domains. The complementation analysis showed that both the ORFs equally suppressed UV sensitivity of yeast rad30 deletion strain. Our study has predicted two novel molecular interactions, a highly conserved molecular tetrad of salt bridges and a series of π–π interactions spanning from thumb to PAD. This study suggests these ORFs as the homologues of yeast Polη, and due to its heterogeneity in C. albicans they may play a significant role in pathogenicity.

  9. Genome-wide fitness test and mechanism-of-action studies of inhibitory compounds in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Deming Xu

    2007-06-01

    Full Text Available Candida albicans is a prevalent fungal pathogen amongst the immunocompromised population, causing both superficial and life-threatening infections. Since C. albicans is diploid, classical transmission genetics can not be performed to study specific aspects of its biology and pathogenesis. Here, we exploit the diploid status of C. albicans by constructing a library of 2,868 heterozygous deletion mutants and screening this collection using 35 known or novel compounds to survey chemically induced haploinsufficiency in the pathogen. In this reverse genetic assay termed the fitness test, genes related to the mechanism of action of the probe compounds are clearly identified, supporting their functional roles and genetic interactions. In this report, chemical-genetic relationships are provided for multiple FDA-approved antifungal drugs (fluconazole, voriconazole, caspofungin, 5-fluorocytosine, and amphotericin B as well as additional compounds targeting ergosterol, fatty acid and sphingolipid biosynthesis, microtubules, actin, secretion, rRNA processing, translation, glycosylation, and protein folding mechanisms. We also demonstrate how chemically induced haploinsufficiency profiles can be used to identify the mechanism of action of novel antifungal agents, thereby illustrating the potential utility of this approach to antifungal drug discovery.

  10. Serum repressing efflux pump CDR1 in Candida albicans

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    Fan Jen-Chung

    2006-07-01

    Full Text Available Abstract Background In the past decades, the prevalence of candidemia has increased significantly and drug resistance has also become a pressing problem. Overexpression of CDR1, an efflux pump, has been proposed as a major mechanism contributing to the drug resistance in Candida albicans. It has been demonstrated that biological fluids such as human serum can have profound effects on antifungal pharmacodynamics. The aim of this study is to understand the effects of serum in drug susceptibility via monitoring the activity of CDR1 promoter of C. albicans. Results The wild-type C. albicans cells (SC5314 but not the cdr1/cdr1 mutant cells became more susceptible to the antifungal drug when the medium contained serum. To understand the regulation of CDR1 in the presence of serum, we have constructed CDR1 promoter-Renilla luciferase (CDR1p-RLUC reporter to monitor the activity of the CDR1 promoter in C. albicans. As expected, the expression of CDR1p-RLUC was induced by miconazole. Surprisingly, it was repressed by serum. Consistently, the level of CDR1 mRNA was also reduced in the presence of serum but not N-acetyl-D-glucosamine, a known inducer for germ tube formation. Conclusion Our finding that the expression of CDR1 is repressed by serum raises the question as to how does CDR1 contribute to the drug resistance in C. albicans causing candidemia. This also suggests that it is important to re-assess the prediction of in vivo therapeutic outcome of candidemia based on the results of standard in vitro antifungal susceptibility testing, conducted in the absence of serum.

  11. Study of Candida Albicans Vaginitis Model in Kunming Mice

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhuo; KONG Xiaofeng

    2007-01-01

    The model of vaginal candidiasis in Kunming mice was constructed in order to search for the optima construction conditions and provide an economic animal model of Candida albicans (C.albicans) vaginitis. Estrogen benzoate (E2) was given to mice at different concentrations ranging from 0.0 to 0.05 mg/mouse (4 levels) beginning 72 h prior to vaginal inoculation, then mice were inoculated intravaginally with various concentrations of stationary-phase C. albicans blastoconidia (ATCC90028) (5 levels) in 20 μL of phosphate-buffered saline (PBS) in each F2 level. General state,scores of genital pathology, the hyphae and vaginal fungal burden (CFU) in vaginal lavage fluid, the hydrops rate of uterus and vaginal tissues for pathological section in mice were observed and obtained at day 2, 4, 7, 14 and 21 after inoculation. The results showed the infection rate in mice was related to the dosage of E2 and concentration of C. albicans blastoconidia. Additionally there was better cross-effect between the two treated factors. The infection rate was about 80% on the day 4,and could reach 100% on the day 7 until the end of experiment after inoculated intravaginally in groups of E2I3, E2 0.025 mg/mouse injected hypodermically and inoculated intravaginally with 5×104 C. albicans blastoconidia, and large amount of hyphae and blastoconidia could be observe in superficial layer tissue and canal of vaginal by PAS. From the results in our experiment it was concluded that E2I3 was the optima construction condition in kunming mice.

  12. Critical role for CaFEN1 and CaFEN12 of Candida albicans in cell wall integrity and biofilm formation

    Science.gov (United States)

    Alfatah, Md.; Bari, Vinay K.; Nahar, Anubhav S.; Bijlani, Swati; Ganesan, K.

    2017-01-01

    Sphingolipids are involved in several cellular functions, including maintenance of cell wall integrity. To gain insight into the role of individual genes of sphingolipid biosynthetic pathway, we have screened Saccharomyces cerevisiae strains deleted in these genes for sensitivity to cell wall perturbing agents calcofluor white and congo red. Only deletants of FEN1 and SUR4 genes were found to be sensitive to both these agents. Candida albicans strains deleted in their orthologs, CaFEN1 and CaFEN12, respectively, also showed comparable phenotypes, and a strain deleted for both these genes was extremely sensitive to cell wall perturbing agents. Deletion of these genes was reported earlier to sensitise cells to amphotericin B (AmB), which is a polyene drug that kills the cells mainly by binding and sequestering ergosterol from the plasma membrane. Here we show that their AmB sensitivity is likely due to their cell wall defect. Further, we show that double deletant of C. albicans is defective in hyphae formation as well as biofilm development. Together this study reveals that deletion of FEN1 and SUR4 orthologs of C. albicans leads to impaired cell wall integrity and biofilm formation, which in turn sensitise cells to AmB. PMID:28079132

  13. Effect of plagiochin E, an antifungal macrocyclic bis(bibenzyl), on cell wall chitin synthesis in Candida albicans

    Institute of Scientific and Technical Information of China (English)

    Xiu-zhen WU; Ai-xia CHENG; Ling-mei SUN; Hong-xiang LOU

    2008-01-01

    Aim: To investigate the effect of plagiochin E (PLE), an antifungal macrocyclic bis(bibenzyl) isolated from liverwort Marchantia polymorpha L, on cell wall chitin synthesis in Candida albicans. Methods: The effect of PLE on chitin synthesis in Candida albicans was investigated at the cellular and molecular lev-els. First, the ultrastructural changes were observed under transmission electron microscopy (TEM). Second, the effects of PLE on chitin synthetase (Chs) activi-ties in vitro were assayed using 6-O-dansyl-N-acetylglucosamine as a fluorescent substrate, and its effect on chitin synthesis in situ was assayed by spheroplast regeneration. Finally, real-time RT-PCR was performed to assay its effect on the expression of Chs genes (CHS). Results: Observation under TEM showed that the structure of the cell wall in Candida albicans was seriously damaged, which suggested that the antifungal activity of PLE was associated with its effect on the cell wail. Enzymatic assays and spheroplast regeneration showed that PLE inhibited chitin synthesis in vitro and in situ. The results of the PCR showed that PLE significantly downregulated the expression of CHS1, and upregulated the expression of CHS2 and CHS3. Because different Chs is regulated at different stages of transcription and post-translation, the downregulation of CHS1 would decrease the level of Chs 1 and inhibit its activity, and the inhibitory effects of PLE on Chs2 and Chs3 would be at the post-translational level or by the inhibi-tion on the enzyme-active center. Conclusion: These results indicate that the antifungal activity of PLE would be attributed to its inhibitory effect on cell wall chitin synthesis in Candida albicans.

  14. The development of fluconazole resistance in Candida albicans - an example of microevolution of a fungal pathogen.

    Science.gov (United States)

    Morschhäuser, Joachim

    2016-03-01

    The yeast Candida albicans is a member of the microbiota in the gastrointestinal and urogenital tracts of most healthy persons, but it can also cause symptomatic infections, especially in immunocompromised patients. During the life-long association with its human host, C. albicans generates genetically altered variants that are better adapted to changes in their environment. A prime example of this microevolution is the development of resistance to the commonly used drug fluconazole, which inhibits ergosterol biosynthesis, during antimycotic therapy. Fluconazole resistance can be caused by mutations in the drug target, by changes in the sterol biosynthesis pathway, and by gain-of-function mutations in transcription factors that result in the constitutive upregulation of ergosterol biosynthesis genes and multidrug efflux pumps. Fluconazole also induces genomic rearrangements that result in gene amplification and loss of heterozygosity for resistance mutations, which further increases drug resistance. These genome alterations may affect extended chromosomal regions and have additional phenotypic consequences. A striking case is the loss of heterozygosity for the mating type locus MTL in many fluconazole-resistant clinical isolates, which allows the cells to switch to the mating-competent opaque phenotype. This, in turn, raises the possibility that sexual recombination between different variants of an originally clonal, drug-susceptible population may contribute to the generation of highly fluconazole-resistant strains with multiple resistance mechanisms. The gain-of-function mutations in transcription factors, which result in deregulated gene expression, also cause reduced fitness. In spite of this, many clinical isolates that contain such mutations do not exhibit fitness defects, indicating that they have overcome the costs of drug resistance with further evolution by still unknown mechanisms.

  15. Novel role of a family of major facilitator transporters in biofilm development and virulence of Candida albicans.

    Science.gov (United States)

    Shah, Abdul Haseeb; Singh, Ashutosh; Dhamgaye, Sanjiveeni; Chauhan, Neeraj; Vandeputte, Patrick; Suneetha, Korivi Jyothiraj; Kaur, Rupinder; Mukherjee, Pranab K; Chandra, Jyotsna; Ghannoum, Mahmoud A; Sanglard, Dominique; Goswami, Shyamal K; Prasad, Rajendra

    2014-06-01

    The QDR (quinidine drug resistance) family of genes encodes transporters belonging to the MFS (major facilitator superfamily) of proteins. We show that QDR transporters, which are localized to the plasma membrane, do not play a role in drug transport. Hence, null mutants of QDR1, QDR2 and QDR3 display no alterations in susceptibility to azoles, polyenes, echinocandins, polyamines or quinolines, or to cell wall inhibitors and many other stresses. However, the deletion of QDR genes, individually or collectively, led to defects in biofilm architecture and thickness. Interestingly, QDR-lacking strains also displayed attenuated virulence, but the strongest effect was observed with qdr2∆, qdr3∆ and in qdr1/2/3∆ strains. Notably, the attenuated virulence and biofilm defects could be reversed upon reintegration of QDR genes. Transcripts profiling confirmed differential expression of many biofilm and virulence-related genes in the deletion strains as compared with wild-type Candida albicans cells. Furthermore, lipidomic analysis of QDR-deletion mutants suggests massive remodelling of lipids, which may affect cell signalling, leading to the defect in biofilm development and attenuation of virulence. In summary, the results of the present study show that QDR paralogues encoding MFS antiporters do not display conserved functional linkage as drug transporters and perform functions that significantly affect the virulence of C. albicans.

  16. Alcohol dehydrogenase Ⅰ expression correlates with CDR1, CDR2 and FLU1 expression in Candida albicans from patients with vulvovaginal candidiasis

    Institute of Scientific and Technical Information of China (English)

    GUO Hui; ZHANG Xiao-li; GAO Lai-qiang; LI Shui-xiu; SONG Yan-jun; ZHANG Hong

    2013-01-01

    Background The most critical mechanism governing drug resistance in Candida albicans (C.albicans) involves efflux pumps,the functionality of which largely depends on energy metabolism.Alcohol dehydrogenase Ⅰ (ADH1) plays an important role in intracellular energy metabolism.The aim of this study was to explore the relationship between ADH1 and drug resistance in C.albicans.Methods Twenty clinical C.albicans samples isolated from individual patients diagnosed with vulvovaginal candidiasis,and two C.albicans strains obtained from a single parental source (the fluconazole (FLC)-sensitive strain CA-1S and the FLC-resistant strain CA-16R) were included in our study.In accordance with the Clinical and Laboratory Standards Institute (CLSI) M27-A3 guidelines,we used the microdilution method to examine the FLC minimum inhibitory concentrations (MICs) and real-time reverse transcription polymerase chain reaction (RT-PCR) to measure the mRNA expression levels of ADH1 and the azole resistance genes CDR1,CDR2,MDR1,FLU1 and ERG11 in all the isolates.Results A highly significant positive correlation between the mRNA levels of ADH1 and the MICs (rs =0.921,P=0.000),as well as positive correlations between the mRNA level of ADH1 and those of CDR1,CDR2 and FLU1 (rs of 0.704,0.772 and 0.779,respectively,P <0.01),were observed in the 20 clinical C.albicans samples.The relative expression of ADH1 was upregulated 10.63-to 17.61-fold in all of the drug-resistant isolates.No correlations were found between the mRNA levels of ADH1 and those of MDR1 or ERG11 (P >0.05).The mRNA levels of the examined drug resistance genes were higher in the CA-16R strain than in CA-1S,and the mRNA levels of ADH1 in CA-16R were 11.64-fold higher than those in CA-1S (P <0.05).Conclusions These results suggest that high levels of ADH1 transcription are implicated in FLC resistance in C.albicans and that the mRNA expression levels of ADH1 are positively correlated with those of CDR1,CDR2 and FLU1.

  17. Effect of Piper betle and Brucea javanica on the Differential Expression of Hyphal Wall Protein (HWP1) in Non-Candida albicans Candida (NCAC) Species.

    Science.gov (United States)

    Wan Harun, Wan Himratul Aznita; Jamil, Nur Alyaa; Jamaludin, Nor Hazwani; Nordin, Mohd-Al-Faisal

    2013-01-01

    The study aimed to identify the HWP1 gene in non-Candida albicans Candida species and the differential expression of HWP1 following treatment with Piper betle and Brucea javanica aqueous extracts. All candidal suspensions were standardized to 1 × 10(6) cells/mL. The suspension was incubated overnight at 37 °C (C. parapsilosis, 35°C). Candidal cells were treated with each respective extract at 1, 3, and 6 mg/mL for 24 h. The total RNA was extracted and reverse transcription-polymerase chain reaction was carried out with a specific primer of HWP1. HWP1 mRNAs were only detected in C. albicans, C. parapsilosis, and C. tropicalis. Exposing the cells to the aqueous extracts has affected the expression of HWP1 transcripts. C. albicans, C. parapsilosis, and C. tropicalis have demonstrated different intensity of mRNA. Compared to P. betle, B. javanica demonstrated a higher suppression on the transcript levels of HWP1 in all samples. HWP1 was not detected in C. albicans following the treatment of B. javanica at 1 mg/mL. In contrast, C. parapsilosis and C. tropicalis were shown to have HWP1 regulation. However, the expression levels were reduced upon the addition of higher concentration of B. javanica extract. P. betle and B. javanica have potential to be developed as oral health product.

  18. Effect of Piper betle and Brucea javanica on the Differential Expression of Hyphal Wall Protein (HWP1 in Non-Candida albicans Candida (NCAC Species

    Directory of Open Access Journals (Sweden)

    Wan Himratul Aznita Wan Harun

    2013-01-01

    Full Text Available The study aimed to identify the HWP1 gene in non-Candida albicans Candida species and the differential expression of HWP1 following treatment with Piper betle and Brucea javanica aqueous extracts. All candidal suspensions were standardized to 1×106 cells/mL. The suspension was incubated overnight at 37 °C (C. parapsilosis, 35°C. Candidal cells were treated with each respective extract at 1, 3, and 6 mg/mL for 24 h. The total RNA was extracted and reverse transcription-polymerase chain reaction was carried out with a specific primer of HWP1. HWP1 mRNAs were only detected in C. albicans, C. parapsilosis, and C. tropicalis. Exposing the cells to the aqueous extracts has affected the expression of HWP1 transcripts. C. albicans, C. parapsilosis, and C. tropicalis have demonstrated different intensity of mRNA. Compared to P. betle, B. javanica demonstrated a higher suppression on the transcript levels of HWP1 in all samples. HWP1 was not detected in C. albicans following the treatment of B. javanica at 1 mg/mL. In contrast, C. parapsilosis and C. tropicalis were shown to have HWP1 regulation. However, the expression levels were reduced upon the addition of higher concentration of B. javanica extract. P. betle and B. javanica have potential to be developed as oral health product.

  19. Als1 and Als3 regulate the intracellular uptake of copper ions when Candida albicans biofilms are exposed to metallic copper surfaces.

    Science.gov (United States)

    Zheng, Sha; Chang, Wenqiang; Li, Chen; Lou, Hongxiang

    2016-05-01

    Copper surfaces possess efficient antimicrobial effect. Here, we reported that copper surfaces could inactivate Candida albicans biofilms within 40 min. The intracellular reactive oxygen species in C. albicans biofilms were immediately stimulated during the contact of copper surfaces, which might be an important factor for killing the mature biofilms. Copper release assay demonstrated that the copper ions automatically released from the surface of 1 mm thick copper coupons with over 99.9% purity are not the key determinant for the copper-mediated killing action. The susceptibility test to copper surfaces by using C. albicans mutant strains, which were involved in efflux pumps, adhesins, biofilms formation or osmotic stress response showed that als1/als1 and als3/als3 displayed higher resistance to the copper surface contact than other mutants did. The intracellular concentration of copper ions was lower in als1/als1 and als3/als3 than that in wild-type strain. Transcriptional analysis revealed that the expression of copper transporter-related gene, CRP1, was significantly increased in als1/als1, als3/als3, suggesting a potential role of ALS1 and ALS3 in absorbing ions by regulating the expression of CRP1 This study provides a potential application in treating pathogenic fungi by using copper surfaces and uncovers the roles of ALS1 and ALS3 in absorbing copper ions for C. albicans.

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

    Science.gov (United States)

    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 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.

  1. Vulvovaginal candidiasis: species distribution, fluconazole resistance and drug efflux pump gene overexpression.

    Science.gov (United States)

    Zhang, Jie-Yu; Liu, Jin-Hui; Liu, Fa-Di; Xia, Yan-Hua; Wang, Jing; Liu, Xi; Zhang, Zhi-Qin; Zhu, Na; Yan-Yan; Ying, Ying; Huang, Xiao-Tian

    2014-10-01

    The increasing incidence of vulvovaginal candidiasis (VVC) and the emergence of fluconazole resistance are an indisputable fact. However, little information is available regarding the correlation between fluconazole resistance in vaginal Candida albicans and the expression of drug efflux pump genes. In this study, we investigated the species distribution, fluconazole susceptibility profiles and the mechanisms of fluconazole resistance in Candida strains. In total, 785 clinical Candida isolates were collected from patients with VVC. C. albicans was the most frequently isolated species(n = 529) followed by C. glabrata (n = 164) and C. krusei (n = 57). Of all Candida isolates, 4.7% were resistant to fluconazole. We randomly selected 18 fluconazole resistant isolates of C. albicans to evaluate the expression of CDR1, CDR2, MDR1 and FLU1 genes. Compared with fluconazole-susceptible C. albicans isolates, CDR1 gene expression displayed 3.16-fold relative increase, which was statistically significant. CDR2, MDR1 and FLU1 overexpression was observed in several fluconazole-resistant C. albicans isolates, but statistical significance was not achieved. These results demonstrate a high frequency of non-albicans species (32.6%); however, C. albicans is the most common Candida species implicated in vaginitis, and this strain displays considerable fluconazole resistance. Meanwhile, our study further indicates that fluconazole resistance in C. albicans may correlate with CDR1 gene overexpression.

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

    Directory of Open Access Journals (Sweden)

    Sanjiveeni Dhamgaye

    Full Text Available 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.

  3. Marker Recycling in Candida albicans through CRISPR-Cas9-Induced Marker Excision

    Science.gov (United States)

    2017-01-01

    ABSTRACT We describe here a new approach to marker recycling, a controlled sequence of steps in which a genetic marker is selected and then lost. Marker recycling is important for genetic manipulation, because it allows a single selection marker to be used repeatedly. Our approach relies upon the ability of the CRISPR-Cas9 system to make a targeted double-strand break in DNA and the expectation that a double-strand break within a selection marker may promote recombination between directly repeated sequences that flank the marker. We call the approach CRISPR-Cas9-induced marker excision (CRIME). We tested the utility of this approach with the fungal pathogen Candida albicans, which is typically diploid. We used two selection markers, modified to include flanking direct repeats. In a proof-of-principle study, we created successive homozygous deletions in three genes through use of the two markers and had one of the markers available in the final strain for further selection and recycling. This strategy will accelerate the creation of multiple-mutant strains in C. albicans. CRISPR-Cas9 systems have been applied to many organisms, so the genetic design principles described here may be broadly applicable. IMPORTANCE It is critical to be able to alter genes in order to elucidate their functions. These alterations often rely upon markers that allow selection for a rare cell in a population that has incorporated a piece of DNA. The number of alterations that can be accomplished is thus limited by the number of selection markers that are available. This limitation is circumvented by marker recycling strategies, in which a marker is eliminated after its initial use. Then, the marker can be used again. In this report, we describe a new marker recycling strategy that is enabled by recently developed CRISPR-Cas9 technology. PMID:28317025

  4. A Novel Cold-Active Lipase from Candida albicans: Cloning, Expression and Characterization of the Recombinant Enzyme

    OpenAIRE

    Dong-Ming Lan; Yong-Hua Wang; Bo Yang; Ning Yang; Wen-Kai Wang; Yan-Fei Shen

    2011-01-01

    A novel lipase gene lip5 from the yeast Candida albicans was cloned and sequenced. Alignment of amino acid sequences revealed that 86–34% identity exists with lipases from other Candida species. The lipase and its mutants were expressed in the yeast Pichia pastoris, where alternative codon usage caused the mistranslation of 154-Ser and 293-Ser as leucine. 154-Ser to leucine resulted in loss of expression of Lip5, and 293-Ser to leucine caused a marked reduction in the lipase activity. Lip5-DM...

  5. Molecular methods for strain typing of Candida albicans: a review.

    Science.gov (United States)

    Saghrouni, F; Ben Abdeljelil, J; Boukadida, J; Ben Said, M

    2013-06-01

    Candida albicans is one of the most medically important fungi because of its high frequency as a commensal and pathogenic microorganism causing superficial as well as invasive infections. Strain typing and delineation of the species are essential for understanding its biology, epidemiology and population structure. A wide range of molecular techniques have been used for this purpose including non-DNA-based methods (multi-locus enzyme electrophoresis), conventional DNA-based methods (electrophoretic karyotyping, random amplified polymorphic DNA, amplified fragment length polymorphism, restriction enzyme analysis with and without hybridization, rep-PCR) and DNA-based methods called exact typing methods because they generate unambiguous and highly reproducible typing data (including microsatellite length polymorphism and multi-locus sequence typing). In this review, the main molecular methods used for C. albicans strain typing are summarized, and their advantages and limitations are discussed with regard to their discriminatory power, reproducibility, cost and ease of performance.

  6. Tyrosol is a quorum-sensing molecule in Candida albicans

    OpenAIRE

    Chen, Hao; Fujita, Masaki; Feng, Qinghua; Clardy, Jon; Fink, Gerald R.

    2004-01-01

    The human fungal pathogen Candida albicans shows a significant lag in growth when diluted into fresh minimal medium. This lag is abolished by the addition of conditioned medium from a high-density culture. The active component of conditioned medium is tyrosol, which is released into the medium continuously during growth. Under conditions permissive for germ-tube formation, tyrosol stimulates the formation of these filamentous protrusions. Because germ-tube formation is inhibited by farnesol, ...

  7. ANTAGONISTIC EFFECT OF EDIBLE MUSHROOM EXTRACT ON CANDIDA ALBICANS GROWTH

    Directory of Open Access Journals (Sweden)

    Paccola Edneia A. de Souza

    2001-01-01

    Full Text Available Five species of edible mushrooms, Lentinula edodes, Pleurotus ostreatus, Pholiota nameko, Macrolepiota bonaerensis and Agaricus blazei, were tested for their potential to inhibit the in vitro growth of the pathogenic yeast Candida albicans. Only L. edodes had a fungistatic effect on this human pathogen. The inhibitory compound was produced intra and extracellularly in submersed L. edodes culture, and was also present in fresh and dehydrated mushroom basidiocarps. The fungistatic compound was heat sensitive and lost activity after 72 hours.

  8. MOLECULAR TYPING OF Candida albicans ISOLATES FROM HOSPITALIZED PATIENTS

    Directory of Open Access Journals (Sweden)

    Patricia de Souza Bonfim-Mendonca

    2013-12-01

    Full Text Available SUMMARY Introduction: The majority of nosocomial fungal infections are caused by Candida spp. where C. albicans is the species most commonly identified. Molecular methods are important tools for assessing the origin of the yeasts isolated in hospitals. Methods: This is a study on the genetic profifiles of 39 nosocomial clinical isolates of C. albicans using two typing methods: random amplifified polymorphic DNA (RAPD and microsatellite, two different primers for each technique were used. Results: RAPD provided 10 and 11 different profiles with values for SAB of 0.84 ± 0.126 and 0.88 ± 0.08 for primers M2 and P4, respectively. Microsatellite using two markers, CDC3 and HIS3, allowed the observation of six and seven different alleles, respectively, with combined discriminatory power of 0.91. Conclusions: Although genetic variability is clear, it was possible to identify high similarity, suggesting a common origin for at least a part of isolates. It is important to emphasize that common origin was proven from yeasts isolated from colonization (urine, catheter or endotracheal secretions and blood culture from the same patient, indicating that the candidemia must have started from a site of colonization. The combination of RAPD and microsatellite provides a quick and efficient analysis for investigation of similarity among nosocomial isolates of C. albicans.

  9. Antiarthritic effect of lonicerin on Candida albicans arthritis in mice.

    Science.gov (United States)

    Lee, Jue-Hee; Han, Yongmoon

    2011-05-01

    Fungal arthritis is a potentially serious disease resulting in rapid destruction of the joint. Among the various Candida species, Candida albicans is the most commonly associated with fungal arthritis. In the present study, we examined the effect of lonicerin, a flavonoid isolated from Lonicerae Flos, on an arthritis caused by C. albicans cell wall (CACW) in mice. To examine the effect, an emulsified mixture of CACW and complete Freund's adjuvant (CACW/CFA) was injected into BALB/c mice via hind footpad route on days -3, -2, and -1. On Day 0, mice with the swollen footpad received lonicerin at 1 or 2 mg/dose/time intraperitoneally 3 times every other day. The footpad-swelling was measured for 20 days. Results showed that the lonicerin treatment reduced the edema at all dose levels, and, furthermore, there was app. 54% edema reduction in animals given the 2 mg-dose at the peak (day 10) of septic arthritis (p arthritis. In addition, the flavonoid had anticandidal activity (p fungal arthritis due to C. albicans infection.

  10. Distribution of Candida albicans genotypes among family members

    Science.gov (United States)

    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.

  11. Interactions of Candida albicans with host epithelial surfaces

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    David W. Williams

    2013-10-01

    Full Text Available Candida albicans is an opportunistic, fungal pathogen of humans that frequently causes superficial infections of oral and vaginal mucosal surfaces of debilitated and susceptible individuals. The organism is however, commonly encountered as a commensal in healthy individuals where it is a component of the normal microflora. The key determinant in the type of relationship that Candida has with its host is how it interacts with the epithelial surface it colonises. A delicate balance clearly exists between the potentially damaging effects of Candida virulence factors and the nature of the immune response elicited by the host. Frequently, it is changes in host factors that lead to Candida seemingly changing from a commensal to pathogenic existence. However, given the often reported heterogeneity in morphological and biochemical factors that exist between Candida species and indeed strains of C. albicans, it may also be the fact that colonising strains differ in the way they exploit resources to allow persistence at mucosal surfaces and as a consequence this too may affect the way Candida interacts with epithelial cells. The aim of this review is to provide an overview of some of the possible interactions that may occur between C. albicans and host epithelial surfaces that may in turn dictate whether Candida removal, its commensal persistence or infection follows.

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

    Science.gov (United States)

    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.

  13. Rapid redistribution of phosphatidylinositol-(4,5)-bisphosphate and septins during the Candida albicans response to caspofungin.

    Science.gov (United States)

    Badrane, Hassan; Nguyen, M Hong; Blankenship, Jill R; Cheng, Shaoji; Hao, Binghua; Mitchell, Aaron P; Clancy, Cornelius J

    2012-09-01

    We previously showed that phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P2] and septin regulation play major roles in maintaining Candida albicans cell wall integrity in response to caspofungin and other stressors. Here, we establish a link between PI(4,5)P2 signaling and septin localization and demonstrate that rapid redistribution of PI(4,5)P2 and septins is part of the natural response of C. albicans to caspofungin. First, we studied caspofungin-hypersusceptible C. albicans irs4 and inp51 mutants, which have elevated PI(4,5)P2 levels due to loss of PI(4,5)P2-specific 5'-phosphatase activity. PI(4,5)P2 accumulated in discrete patches, rather than uniformly, along surfaces of mutants in yeast and filamentous morphologies, as visualized with a green fluorescent protein (GFP)-pleckstrin homology domain. The patches also contained chitin (calcofluor white staining) and cell wall protein Rbt5 (Rbt5-GFP). By transmission electron microscopy, patches corresponded to plasma membrane invaginations that incorporated cell wall material. Fluorescently tagged septins Cdc10 and Sep7 colocalized to these sites, consistent with well-described PI(4,5)P2-septin physical interactions. Based on expression patterns of cell wall damage response genes, irs4 and inp51 mutants were firmly positioned within a group of caspofungin-hypersusceptible, septin-regulatory protein kinase mutants. irs4 and inp51 were linked most closely to the gin4 mutant by expression profiling, PI(4,5)P2-septin-chitin redistribution and other phenotypes. Finally, sublethal 5-min exposure of wild-type C. albicans to caspofungin resulted in redistribution of PI(4,5)P2 and septins in a manner similar to those of irs4, inp51, and gin4 mutants. Taken together, our data suggest that the C. albicans Irs4-Inp51 5'-phosphatase complex and Gin4 function upstream of PI(4,5)P2 and septins in a pathway that helps govern responses to caspofungin.

  14. A single nucleotide polymorphism uncovers a novel function for the transcription factor Ace2 during Candida albicans hyphal development.

    Directory of Open Access Journals (Sweden)

    Diana M Calderón-Noreña

    2015-04-01

    Full Text Available Candida albicans is a major invasive fungal pathogen in humans. An important virulence factor is its ability to switch between the yeast and hyphal forms, and these filamentous forms are important in tissue penetration and invasion. A common feature for filamentous growth is the ability to inhibit cell separation after cytokinesis, although it is poorly understood how this process is regulated developmentally. In C. albicans, the formation of filaments during hyphal growth requires changes in septin ring dynamics. In this work, we studied the functional relationship between septins and the transcription factor Ace2, which controls the expression of enzymes that catalyze septum degradation. We found that alternative translation initiation produces two Ace2 isoforms. While full-length Ace2, Ace2L, influences septin dynamics in a transcription-independent manner in hyphal cells but not in yeast cells, the use of methionine-55 as the initiation codon gives rise to Ace2S, which functions as the nuclear transcription factor required for the expression of cell separation genes. Genetic evidence indicates that Ace2L influences the incorporation of the Sep7 septin to hyphal septin rings in order to avoid inappropriate activation of cell separation during filamentous growth. Interestingly, a natural single nucleotide polymorphism (SNP present in the C. albicans WO-1 background and other C. albicans commensal and clinical isolates generates a stop codon in the ninth codon of Ace2L that mimics the phenotype of cells lacking Ace2L. Finally, we report that Ace2L and Ace2S interact with the NDR kinase Cbk1 and that impairing activity of this kinase results in a defect in septin dynamics similar to that of hyphal cells lacking Ace2L. Together, our findings identify Ace2L and the NDR kinase Cbk1 as new elements of the signaling system that modify septin ring dynamics in hyphae to allow cell-chain formation, a feature that appears to have evolved in specific C

  15. Elevated aspartic proteinase secretion and experimental pathogenicity of Candida albicans isolates from oral cavities of subjects infected with human immunodeficiency virus.

    OpenAIRE

    De Bernardis, F; Chiani, P; Ciccozzi, M; Pellegrini, G; Ceddia, T; D'Offizzi, G; Quinti, I; Sullivan, P A; Cassone, A

    1996-01-01

    Isolates of Candida albicans from the oral cavities of subjects at different stages of human immunodeficiency virus (HIV) infection or uninfected controls were examined for (i) production of aspartic proteinase(s), a putative virulence-associated factor(s); (ii) the presence in the fungal genome of two major genes (SAP1 and SAP2) of the aspartic proteinase family; and (iii) experimental pathogenicity in a murine model of systemic infection. It was found that the fungal isolates from symptomat...

  16. The mitochondrial protein Mcu1 plays important roles in carbon source utilization, filamentation, and virulence in Candida albicans.

    Science.gov (United States)

    Guan, Guobo; Wang, Haitao; Liang, Weihong; Cao, Chengjun; Tao, Li; Naseem, Shamoon; Konopka, James B; Wang, Yue; Huang, Guanghua

    2015-08-01

    The fungus Candida albicans is both a pathogen and a commensal in humans. The ability to utilize different carbon sources available in diverse host niches is vital for both commensalism and pathogenicity. N-acetylglucosamine (GlcNAc) is an important signaling molecule as well as a carbon source in C. albicans. Here, we report the discovery of a novel gene MCU1 essential for GlcNAc utilization. Mcu1 is located in mitochondria and associated with multiple energy- and metabolism-related proteins including Por1, Atp1, Pet9, and Mdh1. Consistently, inactivating Por1 impaired GlcNAc utilization as well. Deletion of MCU1 also caused defects in utilizing non-fermentable carbon sources and amino acids. Furthermore, MCU1 is required for filamentation in several inducing conditions and virulence in a mouse systemic infection model. We also deleted TGL99 and GUP1, two genes adjacent to MCU1, and found that the gup1/gup1 mutant exhibited mild defects in the utilization of several carbon sources including GlcNAc, maltose, galactose, amino acids, and ethanol. Our results indicate that MCU1 exists in a cluster of genes involved in the metabolism of carbon sources. Given its importance in metabolism and lack of a homolog in humans, Mcu1 could be a potential target for developing antifungal agents.

  17. Elevated Cell Wall Chitin in Candida albicans Confers Echinocandin Resistance In Vivo

    OpenAIRE

    Lee, K K; MacCallum, D.M; Jacobsen, M.D.; Walker, L A; Odds, F C; Gow, N. A. R.; Munro, C.A.

    2012-01-01

    Candida albicans cells with increased cell wall chitin have reduced echinocandin susceptibility in vitro. The aim of this study was to investigate whether C. albicans cells with elevated chitin levels have reduced echinocandin susceptibility in vivo. BALB/c mice were infected with C. albicans cells with normal chitin levels and compared to mice infected with high-chitin cells. Caspofungin therapy was initiated at 24 h postinfection. Mice infected with chitin-normal cells were successfully tre...

  18. Effect of Xylitol on Candida albicans resistance in serum (in vitro study

    Directory of Open Access Journals (Sweden)

    Ria Puspitawati

    2013-07-01

    Full Text Available Xylitol is reported to inhibit the growth of C. albicans. Objectives: Investigating serum factor role in inhibiting the growth of C. albicans and the effect of 1%, 5%, 10% xylitol on C. albicans resistance in serum in vitro. Methods: Identification of C. albicans (oral swab of candidiasis patient was conducted using CHROMAgar, confirmed by germ tube test. The cultures were serially diluted, inoculated in Saburoud Dextrose Broth (SDB contained 0% (control, 1%, 5%, or 10% xylitol, and kept for 3 or 7 days. These inoculations were then exposed to either active or inactive serum (Fetal Bovine Serum heated in 65ºC for 30 minutes for 2 hours in 37ºC. The colony forming unit (CFU of C. albicans in Saburoud Dextrose Agar (SDA were counted after 2 days. C. albicans ATCC 10231 strain was used as a comparison. One-way ANOVA with 0.05 was used. Results: After 3 days cultured in media with or without xylitol, the CFU of C. albicans exposed to active serum were significantly lower than those exposed to inactive serum (p=0.032. Although not statistically significant (p=0.689, increased concentration of xylitol lead to increased resistance of C. albicans in active serum. Only 7 day exposure of 10% xylitol resulted in significantly higher growth of C. albicans (p=0.034. No significant difference of C. albicans CFU in active or inactive serum (p=0.404. Conclusion: Serum factor has role in inhibiting C. albicans growth in vitro. Exposure of 1%, 5%, or 10% xylitol for 3 or 7 days has no significant effect on C. albicans resistance in serum.DOI: 10.14693/jdi.v16i2.98

  19. Sputum Candida albicans presages FEV₁ decline and hospital-treated exacerbations in cystic fibrosis.

    LENUS (Irish Health Repository)

    Chotirmall, Sanjay H

    2010-11-01

    The role of Candida albicans in the cystic fibrosis (CF) airway is underexplored. Considered a colonizer, few question its pathogenic potential despite high isolation frequencies from sputum culture. We evaluated the frequency and identified the strongest predictors of C albicans colonization in CF. Independent associations of colonization with clinical outcomes were determined, and the longitudinal effects of C albicans acquisition on BMI and FEV₁ were evaluated.

  20. Production of Tyrosol by Candida albicans Biofilms and Its Role in Quorum Sensing and Biofilm Development▿

    OpenAIRE

    Alem, M.A.S.; Oteef, M.D.Y.; Flowers, T; Douglas, L J

    2006-01-01

    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 extra...

  1. ERG2 and ERG24 Are Required for Normal Vacuolar Physiology as Well as Candida albicans Pathogenicity in a Murine Model of Disseminated but Not Vaginal Candidiasis.

    Science.gov (United States)

    Luna-Tapia, Arturo; Peters, Brian M; Eberle, Karen E; Kerns, Morgan E; Foster, Timothy P; Marrero, Luis; Noverr, Mairi C; Fidel, Paul L; Palmer, Glen E

    2015-10-01

    Several important classes of antifungal agents, including the azoles, act by blocking ergosterol biosynthesis. It was recently reported that the azoles cause massive disruption of the fungal vacuole in the prevalent human pathogen Candida albicans. This is significant because normal vacuolar function is required to support C. albicans pathogenicity. This study examined the impact of the morpholine antifungals, which inhibit later steps of ergosterol biosynthesis, on C. albicans vacuolar integrity. It was found that overexpression of either the ERG2 or ERG24 gene, encoding C-8 sterol isomerase or C-14 sterol reductase, respectively, suppressed C. albicans sensitivity to the morpholines. In addition, both erg2Δ/Δ and erg24Δ/Δ mutants were hypersensitive to the morpholines. These data are consistent with the antifungal activity of the morpholines depending upon the simultaneous inhibition of both Erg2p and Erg24p. The vacuoles within both erg2Δ/Δ and erg24Δ/Δ C. albicans strains exhibited an aberrant morphology and accumulated large quantities of the weak base quinacrine, indicating enhanced vacuolar acidification compared with that of control strains. Both erg mutants exhibited significant defects in polarized hyphal growth and were avirulent in a mouse model of disseminated candidiasis. Surprisingly, in a mouse model of vaginal candidiasis, both mutants colonized mice at high levels and induced a pathogenic response similar to that with the controls. Thus, while targeting Erg2p or Erg24p alone could provide a potentially efficacious therapy for disseminated candidiasis, it may not be an effective strategy to treat vaginal infections. The potential value of drugs targeting these enzymes as adjunctive therapies is discussed.

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

    Science.gov (United States)

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

    2016-11-01

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

  3. Hyphal development in Candida albicans requires two temporally linked changes in promoter chromatin for initiation and maintenance.

    Directory of Open Access Journals (Sweden)

    Yang Lu

    2011-07-01

    Full Text Available Phenotypic plasticity is common in development. For Candida albicans, the most common cause of invasive fungal infections in humans, morphological plasticity is its defining feature and is critical for its pathogenesis. Unlike other fungal pathogens that exist primarily in either yeast or hyphal forms, C. albicans is able to switch reversibly between yeast and hyphal growth forms in response to environmental cues. Although many regulators have been found involved in hyphal development, the mechanisms of regulating hyphal development and plasticity of dimorphism remain unclear. Here we show that hyphal development involves two sequential regulations of the promoter chromatin of hypha-specific genes. Initiation requires a rapid but temporary disappearance of the Nrg1 transcriptional repressor of hyphal morphogenesis via activation of the cAMP-PKA pathway. Maintenance requires promoter recruitment of Hda1 histone deacetylase under reduced Tor1 (target of rapamycin signaling. Hda1 deacetylates a subunit of the NuA4 histone acetyltransferase module, leading to eviction of the NuA4 acetyltransferase module and blockage of Nrg1 access to promoters of hypha-specific genes. Promoter recruitment of Hda1 for hyphal maintenance happens only during the period when Nrg1 is gone. The sequential regulation of hyphal development by the activation of the cAMP-PKA pathway and reduced Tor1 signaling provides a molecular mechanism for plasticity of dimorphism and how C. albicans adapts to the varied host environments in pathogenesis. Such temporally linked regulation of promoter chromatin by different signaling pathways provides a unique mechanism for integrating multiple signals during development and cell fate specification.

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

    Science.gov (United States)

    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.

  5. Treatment of serum with supernatants from cultures of Candida albicans reduces its serum-dependent phagocytosis

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    Santos Aderbal Antonio dos

    2002-01-01

    Full Text Available Candida albicans is a potent activator of the complement system, and heat labile opsonins produced by activation of C3 (C3b and iC3b enhance phagocytosis of C. albicans mediated by complement receptors. In this study we treated mouse serum with supernatants from cultures of a protease producer strain of C. albicans and evaluated the ability of this serum to enhance phagocytosis of C. albicans. Cell-free supernatants from cultures of C. albicans were concentrated 5 fold and added to mouse serum for 30 min at 37ºC, before using this serum for opsonization of glutaraldehyde-fixed yeast cells. We observed that normal mouse serum increased about 3 fold the phagocytosis of C. albicans by mice peritoneal macrophages, whereas supernatant-treated serum did not increase phagocytosis. This effect of supernatants on serum was prevented by addition of pepstatin (5 µg/ ml; an inhibitor of C. albicans acid proteases to the medium. Serum treated with supernatants from cultures of a protease-deficient mutant of C. albicans also increased about 3 fold phagocytosis of the yeast. These results suggest that a protease produced by C. albicans causes proteolysis of serum opsonins, thereby reducing the phagocytosis of the yeast.

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

    Science.gov (United States)

    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).

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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).

  9. Arachidonic acid affects biofilm formation and PGE2 level in Candida albicans and non-albicans species in presence of subinhibitory concentration of fluconazole and terbinafine.

    Science.gov (United States)

    Mishra, Nripendra Nath; Ali, Shakir; Shukla, Praveen K

    2014-01-01

    Candida albicans utilizes arachidonic acid (AA) released during the course of infection (Candidiasis) from phospholipids of infected host cell membranes and synthesizes extracellular prostaglandin(s) which play an important role in hyphae formation and host cell damage. C. albicans biofilms secrete significantly more prostaglandin(s) and evidence suggests that Candida biofilms have dramatically reduced susceptibility to majority of antifungal drugs. AA influences the saturation level of lipids and fluidity of yeast cell membranes. Therefore the aim of this study was to evaluate the effect of AA alone or in combination with antifungal agents on biofilm formation and production of prostaglandin (PGE2) in C. albicans, C. parapsilosis, C. glabrata, C. tropicalis, and C. albicans amphotericin B resistant strain (AmBR). Maximum biofilm formation was found to be in the case of C. albicans compared to C. non-albicans species. However, among the non-albicans species C. tropicalis exhibited highest biofilm formation. Treatment with AA in combination with subinhibitory concentrations of fluconazole and terbinafine separately exhibited significant (p<0.05) reduction in biofilm formation against C. glabrata, C. parapsilosis, C. tropicalis and AmBR as compared to their individual effect. Further, these two antifungal agents in combination with AA caused an increase in production of prostaglandin from fungal cell itself which was significant (p<0.05) in case of all the strains tested.

  10. Reverse transcription - 3' rapid amplification of cDNA ends-nested PCR of ACT1 and SAP2 mRNA as a means of detecting viable Candida albicans in an in vitro cutaneous candidiasis model.

    Science.gov (United States)

    Okeke, C N; Tsuboi, R; Kawai, M; Yamazaki, M; Reangchainam, S; Ogawa, H

    2000-01-01

    The presence of viable cells of Candida albicans, in broth or in a reconstructed living skin equivalent, was determined by the detection of amplicons of partial mRNA sequences of the genes encoding fungal actin (ACT1) and secreted aspartyl proteinase 2 (SAP2). The mRNA of both genes were amplified by reverse transcription-3' rapid amplification of cDNA ends-nested polymerase chain reaction. Single bands of ACT1 (315 bp) and SAP2 (162 bp) mRNA were amplified from total RNA extracts of C. albicans grown in yeast carbon base-albumin broth or in living skin equivalent tissue; only the former was amplified from Sabouraud broth-grown organisms. Primer pairs targeted for ACT1 and SAP2 were Candida genus-specific and C. albicans-specific, respectively. The sensitivity limits of the assay were 100 fg of total RNA or 10 cells of C. albicans, by ethidium bromide staining. When C. albicans-infected living skin equivalent was exposed to amorolfine, amplicons of ACT1 and SAP2 mRNA were not detected in total RNA extracts. Non-amplification of the mRNA correlated with the absence of C. albicans growth in Sabouraud agar cultures of living skin equivalent samples. Reverse transcription-3' rapid amplification of cDNA ends-nested polymerase chain reaction of the mRNA encoding specific proteins of an organism has potential application in determining the viability of the organism in tissue, thus monitoring the efficacy of an antimicrobial therapy, and in detecting mRNA expressed in very little amounts in tissue.

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

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    Anand Srinivasan

    Full Text Available 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.

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

    Science.gov (United States)

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

    2011-04-22

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

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

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    Mohamed Ahariz

    2010-08-01

    Full Text Available Mohamed Ahariz1, Philippe Courtois1,21Laboratory of Experimental Hormonology, Université Libre de Bruxelles, Brussels, 2UER de Biologie Médicale, Haute Ecole Francisco Ferrer, Brussels, BelgiumAbstract: The present study aimed to document Candida albicans biofilm development on titanium and its modulation by a peroxidase-precoated material which can generate antimicrobials, such as hypoiodite or hypothiocyanite, from hydrogen peroxide, iodide, or thiocyanate. For this purpose, titanium (powder or foil was suspended in Sabouraud liquid medium inoculated with C. albicans ATCC10231. After continuous stirring for 2–21 days at room temperature, the supernatant was monitored by turbidimetry at 600 nm and titanium washed three times in sterile Sabouraud broth. Using the tetrazolium salt MTT-formazan assay, the titanium-adherent fungal biomass was measured as 7.50 ± 0.60 × 106 blastoconidia per gram of titanium powder (n = 30 and 0.50 ± 0.04 × 106 blastoconidia per cm² of titanium foil (n = 12. The presence of yeast on the surface of titanium was confirmed by microscopy both on fresh preparations and after calcofluor white staining. However, in the presence of peroxidase systems (lactoperoxidase with substrates such as hydrogen peroxide donor, iodide, or thiocyanate, Candida growth in both planktonic and attached phases appeared to be inhibited. Moreover, this study demonstrates the possible partition of peroxidase systems between titanium material (peroxidase-precoated and liquid environment (containing peroxidase substrates to limit C. albicans biofilm formation.Keywords: adhesion, material, oral, yeast

  14. Autophagy is redundant for the host defense against systemic Candida albicans infections

    NARCIS (Netherlands)

    Smeekens, S.P.; Malireddi, R.K.; Plantinga, T.S.; Buffen, K.; Oosting, M.; Joosten, L.A.B.; Kullberg, B.J.; Perfect, J.R.; Scott, W.K.; Veerdonk, F.L. van de; Xavier, R.J.; Vosse, E. van de; Kanneganti, T.D.; Johnson, M.D.; Netea, M.G.

    2014-01-01

    Autophagy has been demonstrated to play an important role in the immunity against intracellular pathogens, but very little is known about its role in the host defense against fungal pathogens such as Candida albicans. Therefore, the role of autophagy for the host defense against C. albicans was asse

  15. Multilocus sequence typing of Candida albicans isolates from Burn Intensive Care Unit (BICU) in Iran

    NARCIS (Netherlands)

    Afsarian, Mohammad H; Badali, Hamid; Boekhout, Teun; Shokohi, Tahereh; Katiraee, Farzad

    2015-01-01

    Burn intensive care unit patients are specifically exposed to deep-seated nosocomial infections caused by Candida albicans. Superficial carriage of C. albicans is a potential source of infection and dissemination, and typing methods could be useful to trace the different isolates. Multilocus sequenc

  16. Isolation of a germ-tube-forming revertant from Candida albicans B311V6.

    OpenAIRE

    Buckley, H R; Daneo-Moore, L; Ahrens, J C; Sobel, J D

    1986-01-01

    We describe and partially characterize the isolation of a germ-tube-positive revertant from Candida albicans B311V6. This revertant has all of the properties of a germ-tube-forming strain of C. albicans except that it appears to have a nutrition defect.

  17. Efek Penambahan Glukosa pada Saburoud Dextrose Broth terhadap Pertumbuhan Candida albicans (Uji In Vitro

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    Lakshmi A. Leepel

    2012-10-01

    Full Text Available High carbohydrate intake is one of predisposing factors of oral candidiasis. Objective: Investigating the effect of 1%,5%,10% glucose addition on the growth of C.albicans in vitro. Method: C.albicans sample was taken from oral swab of a male oral candidiasis patient. Identification of C.albicans was conducted using CHROMagar and confirmed by germ tube formation in serum. As a comparison, C.albicans ATCC10231 was used. After 2 days the cultures were serially diluted and inoculated in SDB without glucose, and with 1%,5%,10% addditional glucose, kept for 3 and 7 days in room temperature, then inoculated in SDA. The CFU/ml were counted after 2 days. ANOVA with α0.05 was used. Result: Statisticaly, additional 1% glucose for 3 days lead to significant decreased of growth of both clinical strain and ATCC 10231 C. albicans. However, only additional 5% and 10% glucose in clinical isolate for 7 days increased the growth of C.albicans significantly. Conclusion: The effect of additional glucose on the increased growth of C.albicans in vitro is influenced by the concentration, exposure duration of glucose, and by the strain of C.albicans.DOI: 10.14693/jdi.v16i1.14

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

    Science.gov (United States)

    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 ...

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

    NARCIS (Netherlands)

    Schlecht, L.M.; Peters, B.M.; Krom, B.P.; Freiberg, J.A.; Hänsch, G.M.; Filler, S.G.; Jabra-Rizk, M.A.; Shirtliff, M.E.

    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

  20. Is Candida albicans a trigger in the onset of coeliac disease?

    NARCIS (Netherlands)

    Nieuwenhuizen, W.F.; Pieters, R.H.H.; Knippels, L.M.J.; Jansen, M.C.J.F.; Koppelman, S.J.

    2003-01-01

    Coeliac disease is a T-cell-mediated autoimmune disease of the small intestine that is induced by ingestion of gluten proteins from wheat, barley, or rye. We postulate that Candida albicans is a trigger in the onset of coeliac disease. The virulence factor of C albicans - hyphal wall protein 1 (HWP1

  1. Candida albicans septicemia in a premature infant successfully treated with oral fluconazole

    DEFF Research Database (Denmark)

    Bodé, S; Pedersen-Bjergaard, Lars; Hjelt, K

    1992-01-01

    A premature male infant, birth-weight 1460 g, was treated successfully for a Candida albicans septicemia with orally administered fluconazole for 20 days. Dosage was 5 mg/kg/day. No side effects were seen. Fluconazole may present a major progress in treatment of invasive C. albicans infections in...... in neonatology....

  2. Biochemical characterization of recombinant dihydroorotate dehydrogenase from the opportunistic pathogenic yeast Candida albicans

    DEFF Research Database (Denmark)

    Zameitat, E.; Gojkovic, Zoran; Knecht, Wolfgang

    2006-01-01

    Candida albicans is the most prevalent yeast pathogen in humans, and recently it has become increasingly resistant to the current antifungal agents. In this study we investigated C. albicans dihydroorotate dehydrogenase (DHODH, EC 1.3.99.11), which catalyzes the fourth step of de novo pyrimidine...

  3. Granulocytes govern the transcriptional response, morphology and proliferation of Candida albicans in human blood.

    NARCIS (Netherlands)

    Fradin, C.; de Groot, P.W.J.; Maccallum, D.; Schaller, M.; Klis, F.M.; Odds, F.C.; Hube, B.

    2005-01-01

    Survival in blood and escape from blood vessels into tissues are essential steps for the yeast Candida albicans to cause systemic infections. To elucidate the influence of blood components on fungal growth, morphology and transcript profile during bloodstream infections, we exposed C. albicans to bl

  4. Cigarette Smoke-Exposed Candida albicans Increased Chitin Production and Modulated Human Fibroblast Cell Responses

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    Humidah Alanazi

    2014-01-01

    Full Text Available The predisposition of cigarette smokers for development of respiratory and oral bacterial infections is well documented. Cigarette smoke can also contribute to yeast infection. The aim of this study was to investigate the effect of cigarette smoke condensate (CSC on C. albicans transition, chitin content, and response to environmental stress and to examine the interaction between CSC-pretreated C. albicans and normal human gingival fibroblasts. Following exposure to CSC, C. albicans transition from blastospore to hyphal form increased. CSC-pretreated yeast cells became significantly (P<0.01 sensitive to oxidation but significantly (P<0.01 resistant to both osmotic and heat stress. CSC-pretreated C. albicans expressed high levels of chitin, with 2- to 8-fold recorded under hyphal conditions. CSC-pretreated C. albicans adhered better to the gingival fibroblasts, proliferated almost three times more and adapted into hyphae, while the gingival fibroblasts recorded a significantly (P<0.01 slow growth rate but a significantly higher level of IL-1β when in contact with CSC-pretreated C. albicans. CSC was thus able to modulate both C. albicans transition through the cell wall chitin content and the interaction between C. albicans and normal human gingival fibroblasts. These findings may be relevant to fungal infections in the oral cavity in smokers.

  5. Intestinal Colonization by Candida albicans Alters Inflammatory Responses in Bruton's Tyrosine Kinase-Deficient Mice

    NARCIS (Netherlands)

    Strijbis, Karin; Yilmaz, Omer H; Dougan, Stephanie K; Esteban, Alexandre; Gröne, Andrea; Kumamoto, Carol A; Ploegh, Hidde L

    2014-01-01

    The commensal yeast Candida albicans is part of the human intestinal microflora and is considered a "pathobiont", a resident microbe with pathogenic potential yet harmless under normal conditions. The aim of this study was to investigate the effect of C. albicans on inflammation of the intestinal tr

  6. Paradoxical antifungal activity and structural observations in biofilms formed by echinocandin-resistant Candida albicans clinical isolates.

    Science.gov (United States)

    Walraven, Carla J; Bernardo, Stella M; Wiederhold, Nathan P; Lee, Samuel A

    2014-02-01

    Echinocandin-resistant clinical isolates of Candida albicans have been reported, and key-hot spot mutations in the FKS1 gene, which encodes a major glucan synthase subunit, have been identified in these (caspofungin-resistant [CAS-R]) strains. Although these mutations result in phenotypic resistance to echinocandins in planktonic cells, there is little data on antifungal susceptibilities of CAS-R C. albicans strains within biofilms. Thus, we analyzed biofilms formed by 12 C. albicans CAS-R clinical strains in which we previously identified FKS1 hot-spot mutations and compared the sessile antifungal and paradoxical activity of anidulafungin (ANID), caspofungin (CAS), and micafungin (MICA). Biofilms were formed in a 96-well static microplate model and assayed using both tetrazolium-salt reduction and crystal violet assays, as well as examination by scanning electron microscopy. We first sought to assess biofilm formation and structure in these fks1 mutants and found that the biofilm mass and metabolic activities were reduced in most of the fks1 mutants as compared with reference strain SC5314. Structural analyses revealed that the fks1 mutant biofilms were generally less dense and had a clear predominance of yeast and pseudohyphae, with unusual "pit"-like cell surface structures. We also noted that sessile minimum inhibitory concentrations (MICs) to ANID, CAS, and MICA were higher than planktonic MICs of all but one strain. The majority of strains demonstrated a paradoxical effect (PE) to particular echinocandins, in either planktonic or sessile forms. Overall, biofilms formed by echinocandin-resistant clinical isolates demonstrated varied PEs to echinocandins and were structurally characterized by a preponderance of yeast, pseudohyphae, and pit-like structures.

  7. A large-scale complex haploinsufficiency-based genetic interaction screen in Candida albicans: analysis of the RAM network during morphogenesis.

    Directory of Open Access Journals (Sweden)

    Nike Bharucha

    2011-04-01

    Full Text Available The morphogenetic transition between yeast and filamentous forms of the human fungal pathogen Candida albicans is regulated by a variety of signaling pathways. How these pathways interact to orchestrate morphogenesis, however, has not been as well characterized. To address this question and to identify genes that interact with the Regulation of Ace2 and Morphogenesis (RAM pathway during filamentation, we report the first large-scale genetic interaction screen in C. albicans.Our strategy for this screen was based on the concept of complex haploinsufficiency (CHI. A heterozygous mutant of CBK1(cbk1Δ/CBK1, a key RAM pathway protein kinase, was subjected to transposon-mediated, insertional mutagenesis. The resulting double heterozygous mutants (6,528 independent strains were screened for decreased filamentation on SpiderMedium (SM. From the 441 mutants showing altered filamentation, 139 transposon insertion sites were sequenced,yielding 41 unique CBK1-interacting genes. This gene set was enriched in transcriptional targets of Ace2 and, strikingly, the cAMP-dependent protein kinase A (PKA pathway, suggesting an interaction between these two pathways. Further analysis indicates that the RAM and PKA pathways co-regulate a common set of genes during morphogenesis and that hyperactivation of the PKA pathway may compensate for loss of RAM pathway function. Our data also indicate that the PKA–regulated transcription factor Efg1 primarily localizes to yeast phase cells while the RAM–pathway regulated transcription factor Ace2 localizes to daughter nuclei of filamentous cells, suggesting that Efg1 and Ace2 regulate a common set of genes at separate stages of morphogenesis. Taken together, our observations indicate that CHI–based screening is a useful approach to genetic interaction analysis in C. albicans and support a model in which these two pathways regulate a common set of genes at different stages of filamentation.

  8. Candida albicans Carriage in Children with Severe Early Childhood Caries (S-ECC) and Maternal Relatedness

    Science.gov (United States)

    Xiao, Jin; Moon, Yonghwi; Li, Lihua; Rustchenko, Elena; Wakabayashi, Hironao; Zhao, Xiaoyi; Feng, Changyong; Gill, Steven R.; McLaren, Sean; Malmstrom, Hans; Ren, Yanfang; Quivey, Robert

    2016-01-01

    Introduction Candida albicans has been detected together with Streptococcus mutans in high numbers in plaque-biofilm from children with early childhood caries (ECC). The goal of this study was to examine the C. albicans carriage in children with severe early childhood caries (S-ECC) and the maternal relatedness. Methods Subjects in this pilot cross-sectional study were recruited based on a convenient sample. DMFT(S)/dmft(s) caries and plaque scores were assessed during a comprehensive oral exam. Social-demographic and related background information was collected through a questionnaire. Saliva and plaque sample from all children and mother subjects were collected. C. albicans were isolated by BBL™ CHROMagar™ and also identified using germ tube test. S. mutans was isolated using Mitis Salivarius with Bacitracin selective medium and identified by colony morphology. Genetic relatedness was examined using restriction endonuclease analysis of the C. albicans genome using BssHII (REAG-B). Multilocus sequence typing was used to examine the clustering information of isolated C. albicans. Spot assay was performed to examine the C. albicans Caspofungin susceptibility between S-ECC children and their mothers. All statistical analyses (power analysis for sample size, Spearman’s correlation coefficient and multiple regression analyses) were implemented with SAS 9.4 Results A total of 18 S-ECC child-mother pairs and 17 caries free child-mother pairs were enrolled in the study. Results indicated high C. albicans carriage rate in the oral cavity (saliva and plaque) of both S-ECC children and their mothers (>80%). Spearman’s correlation coefficient also indicated a significant correlation between salivary and plaque C. albicans and S. mutans carriage (p60% of them demonstrated identical C. albicans REAG-B pattern. C. albicans isolated from >65% of child-mother pairs demonstrated similar susceptibility to caspofungin in spot assay, while no caspofungin resistant strains were

  9. Detection of phospholipase activity of Candida albicans and non albicans isolated from women of reproductive age with vulvovaginal candidiasis in rural area

    Directory of Open Access Journals (Sweden)

    S R Fule

    2015-01-01

    Full Text Available Background: Vulvovaginal candidiasis (VVC is most common accounting for 17 to 39% of symptomatic women. Both Candida albicans and non albicans Candida species are involved in VVC. Amongst various virulence factors proposed for Candida, extracellular phospholipases is one of the virulence factor implicated in its pathogenicity. With this background the present study was carried out to find the prevalence of different Candida species and to detect phospholipase producing strains isolated from symptomatic women with VVC. Materials and Methods: At least two vaginal swabs from 156 women of reproductive age with abnormal vaginal discharge were collected. Direct microscopy and Gram′s stained smear examined for presence of budding yeast and pseudo mycelia followed by isolation and identification of Candida species. Extracellular phospholipase activity was studied by inoculating all isolates on Sabouraud′s dextrose egg yolk agar (SDA medium. Results: Of the 156 women with curdy white discharge alone or in combination with other signs, 59 (37.82% women showed laboratory evidence of VVC. A total of 31 (52.54% women had curdy white discharge followed by 12 (20.33% with other signs and symptoms. C. albicans (62.59% and non albicans Candida (37.28% in a ratio of 1.68:1 were isolated. Of the 37 strains of C. albians 30 (81.08% showed the enzyme activity. Seventeen (56.66% strains showed higher Pz value of < 0.70 (++++. Conclusion: Although there may be typical clinical presentation of Candidiasis. all the patients did not show laboratory evidence of infection. Pregnancy was found to be major risk factor for development of VVC. C. albicans was prevalent species but non albicans species were also frequently isolated. Extracellular phospholipase activity was seen in C. albicans and not in non albicans Candida isolates.

  10. Anti-fungal activity of Morinda citrifolia (noni extracts against Candida albicans: An in vitro study

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    K Barani

    2014-01-01

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

  11. Cell wall proteinaceous components in isolates of Candida albicans and non-albicans species from HIV-infected patients with oropharyngeal candidiasis.

    Science.gov (United States)

    López-Ribot, J L; Kirkpatrick, W R; McAtee, R K; Revankar, S G; Patterson, T F

    1998-09-01

    Oropharyngeal candidiasis (OPC) remains a common opportunistic infection in HIV-infected patients. Candida albicans is the most frequent causative agent of OPC. However, non-albicans spp. are being increasingly isolated. Candidal cell wall proteins and mannoproteins play important roles in the biology and patogenesis of candidiasis. In the present study, we have analyzed the proteinaceous components associated with cell wall extracts from C. albicans, Candida tropicalis, Candida pseudotropicalis, Candida krusei, Candida glabrata, Candida parapsilosis, Candida guilliermondii and Candida rugosa obtained from HIV-infected patients with recurrent OPC. Cell wall proteinaceous components were extracted with beta-mercaptoethanol and analyzed using electrophoresis, immunoblotting (with antisera generated against C. albicans cell wall components, and with serum samples and oral saline rinses from patients with OPC), and lectin-blotting (concanavalin A) techniques. Numerous molecular species were solubilized from the various isolates. Major qualitative and quantitative differences in the polypeptidic and antigenic profiles associated with the cell wall extracts from the different Candida spp. were discernible. Some of the antibody preparations generated against C. albicans cell wall components were able to recognize homologous materials present in the extracts from non-albicans spp. Information on cell wall antigens of Candida species may be important in the therapy and prevention of HIV-related OPC.

  12. [The effects of an aroma candy on oral Candida albicans colony-forming units (CFU) and oral hygiene states in healthy elderly carrying Candida albicans].

    Science.gov (United States)

    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 (poral malodor in the test-candy group was significantly decreased after 7 days ingestion of test-candy (poral hygiene states indicated that in the test-candy group, oral malodor, glutinous feeling, and refreshing feeling significantly improved in comparison with control-candy group (poral health care of elderly carrying C. albicans.

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

    Science.gov (United States)

    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

  14. A novel immune evasion strategy of candida albicans: proteolytic cleavage of a salivary antimicrobial peptide.

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    Timothy F Meiller

    Full Text Available Oropharyngeal candidiasis is an opportunistic infection considered to be a harbinger of AIDS. The etiologic agent Candida albicans is a fungal species commonly colonizing human mucosal surfaces. However, under conditions of immune dysfunction, colonizing C. albicans can become an opportunistic pathogen causing superficial or even life-threatening infections. The reasons behind this transition, however, are not clear. In the oral cavity, salivary antimicrobial peptides are considered to be an important part of the host innate defense system in the prevention of microbial colonization. Histatin-5 specifically has exhibited potent activity against C. albicans. Our previous studies have shown histatin-5 levels to be significantly reduced in the saliva of HIV+ individuals, indicating an important role for histatin-5 in keeping C. albicans in its commensal stage. The versatility in the pathogenic potential of C. albicans is the result of its ability to adapt through the regulation of virulence determinants, most notably of which are proteolytic enzymes (Saps, involved in tissue degradation. In this study, we show that C. albicans cells efficiently and rapidly degrade histatin-5, resulting in loss of its anti-candidal potency. In addition, we demonstrate that this cellular activity is due to proteolysis by a member of the secreted aspartic proteases (Sap family involved in C. albicans pathogenesis. Specifically, the proteolysis was attributed to Sap9, in turn identifying histatin-5 as the first host-specific substrate for that isoenzyme. These findings demonstrate for the first time the ability of a specific C. albicans enzyme to degrade and deactivate a host antimicrobial peptide involved in the protection of the oral mucosa against C. albicans, thereby providing new insights into the factors directing the transition of C. albicans from commensal to pathogen, with important clinical implications for alternative therapy. This report characterizes the

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

    Institute of Scientific and Technical Information of China (English)

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

    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.

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

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    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.

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

    Science.gov (United States)

    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.

  18. Modulation of Candida albicans Biofilm by Different Carbon Sources.

    Science.gov (United States)

    Pemmaraju, Suma C; Pruthi, Parul A; Prasad, R; Pruthi, Vikas

    2016-06-01

    In the present investigation, the role of carbon sources (glucose, lactate, sucrose, and arabinose) on Candida albicans biofilm development and virulence factors was studied on polystyrene microtiter plates. Besides this, structural changes in cell wall component β-glucan in presence of different carbon sources have also been highlighted. Biofilm formation was analyzed by XTT (2,3-bis[2-Methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) reduction assay. Glucose-grown cells exhibited the highest metabolic activity during adhesion among all carbon sources tested (p roughness measurements by atomic force microscopy. Exposure to lactate induced hyphal structures with the highest proteinase activity while arabinose-grown cells formed pseudohyphal structures possessing the highest phospholipase activity. Structural changes in β-glucan characterized by Fourier transform infrared (FTIR) spectroscopy displayed characteristic band of β-glucan at 892 cm(-1) in all carbon sources tested. The β(1→6) to β(1→3) glucan ratio calculated as per the band area of the peak was less in lactate (1.15) as compared to glucose (1.73), sucrose (1.62), and arabinose (2.85). These results signify that carbon sources influence C. albicans biofilm development and modulate virulence factors and structural organization of cell wall component β-glucan.

  19. Heat-shock protein 90 in Candida albicans

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Researches on Candidal heat-shock protein 90 (HSP90) in recent years are summarized.Candida albicans is a commensal pathogen in human and animals.In immunocompromised individuals it behaves as an opportunist pathogen,giving rise to superficial or systemic infections.Systemic candidosis is a common cause of death among immunocompromised and debilitated patients,in which the mortality is as high as 70%.HSP90 is now recognized as an immunodominant antigen in C.albicans and plays a key role in systemic candidosis as a molecular chaperone.The 47-ku peptide is the breakdown product of HSP90.Patients who has recovered from systemic candidosis produce high titre of antibodies to 47-ku antigen,whereas the fatal cases have little antibody or falling titres.The three commonest epitopes of candidal HSP90 have been mapped,epitopes C,B and H.Epitopes C and H are immunogenic.The antibody probes of both epitopes may be developed into a new serological test agents for systemic candidosis due to rather high specificity and sensitivity.The recent results establish HSP90 as an ATP-dependent chaperone that is involved in the folding of cell regulatory proteins and in the refolding of stress-denatured polypeptides.Some researches on fungal HSP90 and the treatment of patients with candidosis are reviewed as well.

  20. Antimicrobial effects of liquid anesthetic isoflurane on Candida albicans

    Science.gov (United States)

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

    2006-01-01

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

  1. Antimicrobial effects of liquid anesthetic isoflurane on Candida albicans

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    Armstead Valerie

    2006-11-01

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

  2. Candida albicans menengitis in a newborn with classical galactosemia

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    Hüseyin Altunhan

    2012-12-01

    Full Text Available Classical galactosemia is a rarely seen carbohydrate metabolismdisorder. The frequency of sepsis significantlyincreases in patients with galactosemia. The most commonagent causing sepsis is E. coli. Sepsis due to fungusin patients with galactosemia is rarely reported. Candidais an important cause of sepsis in newborn intensive careunits especially in newborns with underlying risk factorssuch as prematurity and low birth weight. Although themost common etiologic agent of sepsis is E. coli in caseswith galactosemia, it should be kept in mind that candidamay also be causative agent of sepsis and meningitis inthese patients even though there is no underlying risk factor.Also the clinical and laboratory findings of candidiasismay be obscure. For this reason, especially in newborncandida meningitis, the index of suspicion should be kepthigh for early diagnosis and treatment. In such patientscerebrospinal fluid analysis, culture and brain imagingshould be done necessarily, because early diagnosis andtreatment will be life saving. In this article we reported agalactosemia case with the diagnosis of meningitis andCandida albicans grown in his blood culture derived onthe fourth day of admission to clinic.Key words: Candida albicans, galactosemia, meningitis,newborn, sepsis

  3. Candida albicans susceptibility to lactoperoxidase-generated hypoiodite

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    Mohamed Ahariz

    2010-08-01

    Full Text Available Mohamed Ahariz1, Philippe Courtois21Laboratory of Experimental Hormonology, Université Libre de Bruxelles, Brussels, Belgium; 2Laboratory of Experimental Hormonology, Université Libre de Bruxelles, Brussels, Belgium and UER de Biologie Médicale, Haute Ecole Francisco Ferrer, Brussels, BelgiumAbstract: In vivo, lactoperoxidase produces hypothiocyanite (OSCN- from thiocyanate (SCN- in the presence of hydrogen peroxide (H2O2; in vitro, iodide (I- can be oxidized into hypoiodite (OI- by this enzyme. The aim of this study was to compare in vitro the anti-Candida effect of iodide versus thiocyanate used as lactoperoxidase substrate to prevent Candida biofilms development. Candida albicans ATCC 10231 susceptibility upon both peroxidase systems was tested in three different experimental designs: (i in a liquid culture medium, (ii in an interface model between solid culture medium and gel containing the enzymic systems, (iii in a biofilm model onto titanium and acrylic resin. Yeast growth in liquid medium was monitored by turbidimetry at 600 nm. Material-adherent yeast biomass was evaluated by the tetrazolium salt MTT method. The iodide-peroxidase system has been shown to inhibit Candida biofilm formation at lower substrate concentrations (~200 fold less H2O2 donor and for longer incubation periods than the thiocyanate-peroxidase system. In conclusion, efficiency of lactoperoxidase-generated OI- to prevent C. albicans biofilm development allows refining iodine antifungal use in ex vivo conditions.Keywords: denture, iodide, oral, peroxidase, saliva, titanium

  4. Chloroquine sensitizes biofilms of Candida albicans to antifungal azoles

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    Ravikumar Bapurao Shinde

    2013-08-01

    Full Text Available 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 250 µg/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.

  5. Host-Imposed Copper Poisoning Impacts Fungal Micronutrient Acquisition during Systemic Candida albicans Infections.

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    Joanna Mackie

    Full Text Available Nutritional immunity is a process whereby an infected host manipulates essential micronutrients to defend against an invading pathogen. We reveal a dynamic aspect of nutritional immunity during infection that involves copper assimilation. Using a combination of laser ablation inductively coupled mass spectrometry (LA-ICP MS and metal mapping, immunohistochemistry, and gene expression profiling from infected tissues, we show that readjustments in hepatic, splenic and renal copper homeostasis accompany disseminated Candida albicans infections in the mouse model. Localized host-imposed copper poisoning manifests itself as a transient increase in copper early in the kidney infection. Changes in renal copper are detected by the fungus, as revealed by gene expression profiling and fungal virulence studies. The fungus responds by differentially regulating the Crp1 copper efflux pump (higher expression during early infection and down-regulation late in infection and the Ctr1 copper importer (lower expression during early infection, and subsequent up-regulation late in infection to maintain copper homeostasis during disease progression. Both Crp1 and Ctr1 are required for full fungal virulence. Importantly, copper homeostasis influences other virulence traits-metabolic flexibility and oxidative stress resistance. Our study highlights the importance of copper homeostasis for host defence and fungal virulence during systemic disease.

  6. 建立白色念珠菌蛋白指纹库的研究%A study on establishment of peptide mapping database of Candida albicans

    Institute of Scientific and Technical Information of China (English)

    杨永长; 喻华; 刘华; 肖代雯; 黄文芳

    2014-01-01

    目的:探讨白色念珠菌蛋白指纹库的建立,为白色念珠菌感染快速诊断奠定基础。方法收集96株临床分离的白色念珠菌,提取DNA ,采用聚合酶链反应(PCR)扩增其ITS1-5.8S-ITS2基因片段,利用限制性内切酶对其进行鉴定。应用表面增强激光解析电离飞行时间质谱(SELDI-TOF-MS)仪检测念珠菌蛋白指纹,Ciphergen ProteinChip软件自动采集数据,筛选稳定表达蛋白峰建立白色念珠菌蛋白指纹库,运用经准确鉴定的念珠菌对建立的蛋白指纹库进行验证。结果限制性片段长度多态性分析证实临床分离的所有菌株均为白色念珠菌。SELDI-TOF-MS芯片能捕获15个蛋白峰,其中5个蛋白峰在所有白色念珠菌中均稳定表达,利用相似性分析软件建立白色念珠菌蛋白指纹库,白色念珠菌蛋白指纹与建立数据库的相似性大于95%,而其他种类念珠菌蛋白指纹与数据库的相似性均小于50%。结论白色念珠菌蛋白指纹库的建立为快速诊断白色念珠菌感染提供了理论依据。%Objective To explore the establishment of peptide mapping database of Candida albicans ,laying the foundation for rapid diagnosis of Candida albicans infection .Methods 96 Candida albicans were collected clinically ,and its DNA was extracted . Polymerase chain reaction(PCR) was used to amplify the ITS1-5 .8S-ITS2 gene fragments and restriction endonucleases were a-dopted to identify them .Surface enhanced laser desorption ionization-time of flight-mass spectrometry(SELDI-TOF-MS) instrument was applied to detect the Candida albicans peptide mapping ,and Ciphergen ProteinChip software was used to collect data automati-cally .The established peptide mapping database was verified by confirmed Candida .Results According to restriction fragment length polymorphism analysis ,96 strains were confirmed as Candida albicans .15 peptide peaks were captured by SELDI-TOF-MS chips .Five

  7. Analysis of Two Putative Candida albicans Phosphopantothenoylcysteine Decarboxylase / Protein Phosphatase Z Regulatory Subunits Reveals an Unexpected Distribution of Functional Roles

    Science.gov (United States)

    Petrényi, Katalin; Molero, Cristina; Kónya, Zoltán; Erdődi, Ferenc; Ariño, Joaquin; Dombrádi, Viktor

    2016-01-01

    Protein phosphatase Z (Ppz) is a fungus specific enzyme that regulates cell wall integrity, cation homeostasis and oxidative stress response. Work on Saccharomyces cerevisiae has shown that the enzyme is inhibited by Hal3/Vhs3 moonlighting proteins that together with Cab3 constitute the essential phosphopantothenoylcysteine decarboxylase (PPCDC) enzyme. In Candida albicans CaPpz1 is also involved in the morphological changes and infectiveness of this opportunistic human pathogen. To reveal the CaPpz1 regulatory context we searched the C. albicans database and identified two genes that, based on the structure of their S. cerevisiae counterparts, were termed CaHal3 and CaCab3. By pull down analysis and phosphatase assays we demonstrated that both of the bacterially expressed recombinant proteins were able to bind and inhibit CaPpz1 as well as its C-terminal catalytic domain (CaPpz1-Cter) with comparable efficiency. The binding and inhibition were always more pronounced with CaPpz1-Cter, indicating a protective effect against inhibition by the N-terminal domain in the full length protein. The functions of the C. albicans proteins were tested by their overexpression in S. cerevisiae. Contrary to expectations we found that only CaCab3 and not CaHal3 rescued the phenotypic traits that are related to phosphatase inhibition by ScHal3, such as tolerance to LiCl or hygromycin B, requirement for external K+ concentrations, or growth in a MAP kinase deficient slt2 background. On the other hand, both of the Candida proteins turned out to be essential PPCDC components and behaved as their S. cerevisiae counterparts: expression of CaCab3 and CaHal3 rescued the cab3 and hal3 vhs3 S. cerevisiae mutations, respectively. Thus, both CaHal3 and CaCab3 retained the PPCDC related functions and have the potential for CaPpz1 inhibition in vitro. The fact that only CaCab3 exhibits its phosphatase regulatory potential in vivo suggests that in C. albicans CaCab3, but not CaHal3, acts as a

  8. Competitive Interactions between C. albicans, C. glabrata and C. krusei during Biofilm Formation and Development of Experimental Candidiasis.

    Science.gov (United States)

    Rossoni, Rodnei Dennis; Barbosa, Júnia Oliveira; Vilela, Simone Furgeri Godinho; dos Santos, Jéssica Diane; de Barros, Patrícia Pimentel; Prata, Márcia Cristina de Azevedo; Anbinder, Ana Lia; Fuchs, Beth Burgwyn; Jorge, Antonio Olavo Cardoso; Mylonakis, Eleftherios; Junqueira, Juliana Campos

    2015-01-01

    In this study, we evaluated the interactions between Candida albicans, Candida krusei and Candida glabrata in mixed infections. Initially, these interactions were studied in biofilms formed in vitro. CFU/mL values of C. albicans were lower in mixed biofilms when compared to the single biofilms, verifying 77% and 89% of C. albicans reduction when this species was associated with C. glabrata and C. krusei, respectively. After that, we expanded this study for in vivo host models of experimental candidiasis. G. mellonella larvae were inoculated with monotypic and heterotypic Candida suspensions for analysis of survival rate and quantification of fungal cells in the haemolymph. In the groups with single infections, 100% of the larvae died within 18 h after infection with C. albicans. However, interaction groups achieved 100% mortality after 72 h of infection by C. albicans-C. glabrata and 96 h of infection by C. albicans-C. krusei. C. albicans CFU/mL values from larvae hemolymph were lower in the interacting groups compared with the monoespecies group after 12 h of infection. In addition, immunosuppressed mice were also inoculated with monotypic and heterotypic microbial suspensions to induce oral candidiasis. C. albicans CFU/mL values recovered from oral cavity of mice were higher in the group with single infection by C. albicans than the groups with mixed infections by C. albicans-C. glabrata and C. albicans-C. krusei. Moreover, the group with single infection by C. albicans had a higher degree of hyphae and epithelial changes in the tongue dorsum than the groups with mixed infections. We concluded that single infections by C. albicans were more harmful for animal models than mixed infections with non-albicans species, suggesting that C. albicans establish competitive interactions with C. krusei and C. glabrata during biofilm formation and development of experimental candidiasis.

  9. Candida albicans Agglutinin-Like Sequence (Als Family Vignettes: a Review of Als Protein Structure and Function

    Directory of Open Access Journals (Sweden)

    Lois L. Hoyer

    2016-03-01

    Full Text Available Approximately two decades have passed since the description of the first gene in the Candida albicans ALS (agglutinin-like sequence family. Since that time, much has been learned about the composition of the family and the function of its encoded cell-surface glycoproteins. Solution of the structure of the Als adhesive domain provides the opportunity to evaluate the molecular basis for protein function. This review article is formatted as a series of fundamental questions and explores the diversity of the Als proteins, as well as their role in ligand binding, aggregative effects, and attachment to abiotic surfaces. Interaction of Als proteins with each other, their functional equivalence, and the effects of protein abundance on phenotypic conclusions are also examined. Structural features of Als proteins that may facilitate invasive function are considered. Conclusions that are firmly supported by the literature are presented while highlighting areas that require additional investigation to reveal basic features of the Als proteins, their relatedness to each other, and their roles in C. albicans biology.

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

    Science.gov (United States)

    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.

  11. Antimicrobial activity of calcium hydroxide and chlorhexidine on intratubular Candida albicans

    Institute of Scientific and Technical Information of China (English)

    Ronan Jacques Rezende Delgado; Thaís Helena Gasparoto; Carla Renata Sipert; Claudia Ramos Pinheiro; Ivaldo Gomes de Moraes; Roberto Brandāo Garcia; Marco Antonio Hungaro Duarte; Clóvis Monteiro Bramante; Sérgio Aparecido Torres; Gustavo Pompermaier Garlet; Ana Paula Campanelli; Norberti Bernardineli

    2013-01-01

    This study investigated the efficacy of calcium hydroxide and chlorhexidine gel for the elimination of intratubular Candida albicans (C. albicans). Human single-rooted teeth contaminated with C. albicans were treated with calcium hydroxide, 2% chlorhexidine gel, calcium hydroxide plus 2% chlorhexidine gel, or saline (0.9% sodium chloride) as a positive control. The samples obtained at depths of 0-100 and 100-200 μm from the root canal system were analyzed for C. albicans load by counting the number of colony forming units and for the percentage of viable C. albicans using fluorescence microscopy. First, the antimicrobial activity of calcium hydroxide and the 2% chlorhexidine gel was evaluated by counting the number of colony forming units. After 14 days of intracanal medication, there was a significant decrease in the number of C. albicanscolony forming units at a depth of 0-100 lzm with chlorhexidine treatment either with or without calcium hydroxide compared with the calcium hydroxide only treatment. However, there were no differences in the number of colony forming units at the 100-200 μm depth for any of the medications investigated. C. albicans viability was also evaluated by vital staining techniques and fluorescence microscopy analysis. Antifungal activity against C. albicans significantly increased at both depths in the chlorhexidine groups with and without calcium hydroxide compared with the groups treated with calcium hydroxide only. Treatments with only chlorhexidine or chlorhexidine in combination with calcium hydroxide were effective for elimination of C. albicans.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  14. Presence of extracellular DNA in the Candida albicans biofilm matrix and its contribution to biofilms.

    Science.gov (United States)

    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. The effect of squalene on inflammation factors induced by candida albicans in vivo studies

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jun Haeng [Dept. of Radiology, Nambu University, Gwangju (Korea, Republic of)

    2016-09-15

    In the present study, whether squalene treatment relives inflammatory reactions induced by Candida albicans was checked. The experiment was conducted in vivo using seven experimental animals (ICR mice) per experimental group. Among C. albicans-induced inflammatory factors, TNF-α, IL-6, and NO were observed using the ELISA kits method. Through the experiment, the following conclusions were obtained. 1. In the group infected with C. albicans, it could be identified that squalene treatment was inducing NO generation in renal tissues both on the 1st and 3rd days (p < 0.05). 2. In the group pre-treated(intraperitoneal administration) with SQ (80ml/kg) once per day for seven days and infected with C. albicans, it could be identified that squalene treatment was inducing TNF-α generation in renal tissues only on the 3rd day(p < 0.05). 3. In the group pre-treated(intraperitoneal administration) with SQ (80ml/kg) once per day for seven days and infected with C. albicans, it could be identified that squalene treatment was inducing IL-6 generation in renal tissues only on the 3rd day(p < 0.05). In conclusion, it could be seen that for squalene to suppress C. albicans-induced inflammatory factors, preemptively supplying SQ should be effective. Therefore, effects for recovery from C. albicans-induced immunodepression can be expected from SQ treatment.

  16. A viability assay for Candida albicans based on the electron transfer mediator 2,6-dichlorophenolindophenol.

    Science.gov (United States)

    Hassan, Rabeay Y A; Bilitewski, Ursula

    2011-12-01

    Candida albicans is an opportunistic fungal pathogen with comparably high respiratory activity. Thus, we established a viability test based on 2,6-dichlorophenolindophenol (DCIP), a membrane-permeable electron transfer agent. NADH dehydrogenases catalyze the reduction of DCIP by NADH, and the enzymatic activity can be determined either electrochemically via oxidation reactions of DCIP or photometrically. Among the specific respiratory chain inhibitors, only the complex I inhibitor rotenone decreased the DCIP signal from C. albicans, leaving residual activity of approximately 30%. Thus, the DCIP-reducing activity of C. albicans was largely dependent on complex I activity. C. albicans is closely related to the complex I-negative yeast Saccharomyces cerevisiae, which had previously been used in DCIP viability assays. Via comparative studies, in which we included the pathogenic complex I-negative yeast Candida glabrata, we could define assay conditions that allow a distinction of complex I-negative and -positive organisms. Basal levels of DCIP turnover by S.cerevisiae and C. glabrata were only 30% of those obtained from C. albicans but could be increased to the C. albicans level by adding glucose. No significant increases were observed with galactose. DCIP reduction rates from C. albicans were not further increased by any carbon source.

  17. Candida albicans infection in patients with oral squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Čanković Miloš

    2010-01-01

    Full Text Available Bacground/Aim. Systemic candidiasis in intensive care units remains an improtant problem due to antifungal resistance. Patients undergoing radiotherapy for head and neck cancer are at increased risk of developing oral candidiasis and they more frequent have prior fungi colonization. Due to identification of specific risk factors predisposing to fungal infection in order to threat such patients the aim of this study was to determine the presence of Candida species in patients with oral squamous cell carcinoma and compare it to the control subjects (patients with benign oral mucosal lesions. Methods. A total number of 30 consecutive oral cancer examined patients were included in this prospective study (24 men and 6 women with a mean age of 61.47 years, range 41-81 years. The control group consisted of 30 consecutive patients with histologically proven benign oral mucosal lesions (16 men and 14 women with a mean age of 54.53 years, range 16- 83 years. The samples for mycological examination were obtained by using sterile cotton swabs from the cancer lesion surface and in the patients of the control group from the benign mucosal lesion surface. Samples were inoculated in Sabouraud' dextrose agar. For identification purposes, Mackenzie germ tube test was performend on all isolates. Results. The prevalence of Candida was significantly higher in oral cancer patients than in control subjects (χ2 = 5.455, p = 0.020. Candida was found on nine of the 30 cancer surfaces; 5 (16.7% were identified as non-albicans Candida and 4 (13.3% as Candida albicans. In the control group, only Candida albicans was isolated from 2 (6.7% patients. In this study, no statistically significant differences in the presence of Candida species was found with respect to gender, age, smoking, alcohol consumption, wearing of dental protheses and the site of cancer lesion. Conclusion. The increased prevalence of yeasts on the surfaces of oral carcinoma indicates a need for their

  18. Lipidomics of Candida albicans biofilms reveals phase-dependent production of phospholipid molecular classes and role for lipid rafts in biofilm formation.

    Science.gov (United States)

    Lattif, Ali Abdul; Mukherjee, Pranab K; Chandra, Jyotsna; Roth, Mary R; Welti, Ruth; Rouabhia, Mahmoud; Ghannoum, Mahmoud A

    2011-11-01

    Candida albicans-associated bloodstream infections are linked to the ability of this yeast to form biofilms. In this study, we used lipidomics to compare the lipid profiles of C. albicans biofilms and planktonic cells, in early and mature developmental phases. Our results showed that significant differences exist in lipid composition in both developmental phases. Biofilms contained higher levels of phospholipid and sphingolipids than planktonic cells (nmol per g biomass, Pbiofilms compared to planktonic cells (P≤0.05). The ratio of phosphatidylcholine to phosphatidylethanolamine was lower in biofilms compared to planktonic cells in both early (1.17 vs 2.52, P≤0.001) and late (2.34 vs 3.81, P≤0.001) developmental phases. The unsaturation index of phospholipids decreased with time, with this effect being particularly strong for biofilms. Inhibition of the biosynthetic pathway for sphingolipid [mannosyl diinositolphosphoryl ceramide, M(IP)₂C] by myriocin or aureobasidin A, and disruption of the gene encoding inositolphosphotransferase (Ipt1p), abrogated the ability of C. albicans to form biofilms. The differences in lipid profiles between biofilms and planktonic Candida cells may have important implications for the biology and antifungal resistance of biofilms.

  19. CaMac1, a Candida albicans Copper Ion-sensing Transcription Factor, Pro- motes Filamentous and Invasive Growth in Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    Guang-Hua HUANG; Xin-Yi NIE; Jiang-Ye CHEN

    2006-01-01

    Molecular mechanisms of morphogenesis share many common components between Candida albicans and Saccharomyces cerevisiae. The Kssl-associated MAPK cascade and the cAMP/PKA pathway are two important signal transduction pathways that control morphogenesis in S. cerevisiae. A C. albicans copper ion-sensing transcription factor gene, CaMAC1, was cloned from C. albicans SC5314. Ectopic expression of CaMAC1 in S. cerevisiae promoted filamentous and invasive growth. In diploid cells, CaMacl could suppress the filamentous growth defect of mutants in the Kss 1-associated MAPK pathway and the cAMP/PKA pathway. In haploid strains, ectopic expression of CaMAC1 suppressed the invasive growth defect of mutants in the MAPK pathway (ste7, stel2 and tecl), but failed to suppress the invasive growth defect of thefio8 mutant. Our results suggest that the activation of CaMacl is independent of the MAPK and cAMP/PKA pathways in filament formation, but requires Flo8 factor for invasive growth. In the media containing a high concentration of CuSO4, the yeast filamentous and invasive growth was blocked. The activating effect of CaMacl is inhibited by copper ions.

  20. Antifungal activity of four honeys of different types from Algeria against pathogenic yeast:Candida albicans and Rhodotorula sp.

    Institute of Scientific and Technical Information of China (English)

    Ahmed Moussa; Djebli Noureddine; Aissat Saad; Meslem Abdelmelek; Benhalima Abdelkader

    2012-01-01

    Objective: To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Methods:Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50%and 70%w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains. Results:The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7-23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09-93.48)%and (4.90-99.70)%v/v, respectively. Conclusions:This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans.

  1. Particular Candida albicans strains in the digestive tract of dyspeptic patients, identified by multilocus sequence typing.

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    Yan-Bing Gong

    Full Text Available BACKGROUND: Candida albicans is a human commensal that is also responsible for chronic gastritis and peptic ulcerous disease. Little is known about the genetic profiles of the C. albicans strains in the digestive tract of dyspeptic patients. The aim of this study was to evaluate the prevalence, diversity, and genetic profiles among C. albicans isolates recovered from natural colonization of the digestive tract in the dyspeptic patients. METHODS AND FINDINGS: Oral swab samples (n = 111 and gastric mucosa samples (n = 102 were obtained from a group of patients who presented dyspeptic symptoms or ulcer complaints. Oral swab samples (n = 162 were also obtained from healthy volunteers. C. albicans isolates were characterized and analyzed by multilocus sequence typing. The prevalence of Candida spp. in the oral samples was not significantly different between the dyspeptic group and the healthy group (36.0%, 40/111 vs. 29.6%, 48/162; P > 0.05. However, there were significant differences between the groups in the distribution of species isolated and the genotypes of the C. albicans isolates. C. albicans was isolated from 97.8% of the Candida-positive subjects in the dyspeptic group, but from only 56.3% in the healthy group (P < 0.001. DST1593 was the dominant C. albicans genotype from the digestive tract of the dyspeptic group (60%, 27/45, but not the healthy group (14.8%, 4/27 (P < 0.001. CONCLUSIONS: Our data suggest a possible link between particular C. albicans strain genotypes and the host microenvironment. Positivity for particular C. albicans genotypes could signify susceptibility to dyspepsia.

  2. Multi-Step Pathogenesis and Induction of Local Immune Response by Systemic Candida Albicans Infection in an Intravenous Challenge Mouse Model

    Directory of Open Access Journals (Sweden)

    Voon-Kin Chin

    2014-08-01

    Full Text Available Different murine species differ in their susceptibility to systemic infection with Candida albicans, giving rise to varied host immune responses, and this is compounded by variations in virulence of the different yeast strains used. Hence, this study was aimed at elucidating the pathogenesis of a clinical C. albicans isolate (HVS6360 in a murine intravenous challenge model by examining the different parameters which included the counts of red blood cells and associated components as well as the organ-specific expression profiles of cytokines and chemokines. Kidneys and brains of infected mice have higher fungal recovery rates as compared to other organs and there were extensive yeast infiltration with moderate to severe inflammation seen in kidney and brain tissues. Red blood cells (RBCs and haemoglobin (Hb counts were reduced throughout the infection period. Pattern recognition receptors (PRRs, chemokines and cytokine transcription profiles were varied among the different organs (kidney, spleen and brain over 72 h post infections. Transcription of most of the PRRs, cytokines and chemokines were suppressed at 72 h post infection in spleen while continuous expression of PRRs, cytokines and chemokines genes were seen in brain and kidney. Reduction in red blood cells and haemoglobin counts might be associated with the action of extracellular haemolysin enzyme and haeme oxygenase of C. albicans in conjunction with iron scavenging for the fungal growth. Renal cells responsible for erythropoietin production may be injured by the infection and hence the combined effect of haemolysis plus lack of erythropoietin-induced RBC replenishment leads to aggravated reduction in RBC numbers. The varied local host immune profiles among target organs during systemic C. albicans infection could be of importance for future work in designing targeted immunotherapy through immunomodulatory approaches.

  3. Influence of pH of Candida albicans biofilm in the susceptibility to fluconazole

    OpenAIRE

    2012-01-01

    Resumo: Na cavidade oral, a colonização por Candida albicans em nichos com valores distintos de pH contribui para o desenvolvimento de candidose associada ao uso de prótese. O tratamento dessa infecção tem sido facilitado utilizando-se o fluconazol (FLZ). Entretanto, não está claro se o pH dos biofilmes de C. albicans interfere na susceptibilidade destes ao FLZ. Dessa forma, neste trabalho foi avaliada a influência do pH de biofilmes de C. albicans na susceptibilidade ao FLZ. Testes de suscep...

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

    Science.gov (United States)

    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 terpenoids resulted in significant (p 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.

  5. [Cutaneous candidiosis in an European beaver, Castor fiber. Epidimiological aspect and parasitic form of Candida albicans].

    Science.gov (United States)

    Saëz, H

    1976-12-01

    On the thigh of an Europa Beaver, Castor fiber L., dead after 8 years of captivity, a candidiasis has been found due to Candida albicans. Were reported successively: the frequence of C. albicans in the Europa Beaver and the Canada Beaver, the diagnosis, an epidemiologic aspect and the morphologic parasitic form of that yeast. In the epiderma parasited of the Beaver, C. albicans has developed in a yeast-form in the superficial strates of the skin and in the filamentous-form in the deeper.

  6. An Unusual Cause of Renal and Perirenal Abscesses: Candida albicans

    Directory of Open Access Journals (Sweden)

    Serhan PİŞKİNPAŞA

    2014-01-01

    Full Text Available A 42-year-old female with history of surgery due to urolithiasis was admitted to hospital with complaints of fever, left fl ank pain and vomiting. She was found to have acute kidney injury due to urinary tract infection. Abdominal computed tomography revealed right atrophic kidney and left renal and perirenal abscesses together with urolithiasis. Urine, blood and abscess cultures yielded C. albicans. The patient was treated with fl uconazole and percutaneous drainage of the perirenal abscess, which was 60 mm in diameter. Her serum creatinine returned to the normal ranges within two weeks of hospitalization. Nearly 18 months following this presentation, she has normal serum creatinine and no abscesses in the kidneys.

  7. Phage displaying epitope of Candida albicans HSP90 and serodiagnosis

    Institute of Scientific and Technical Information of China (English)

    杨琼; 王丽; 卢大宁; 邢沈阳; 尹东; 朱筱娟

    2004-01-01

    @@ Recently, the frequent use of immunosuppressants and chemotherapeutic drugs for cancers has caused an increase in the frequency of life-threatening systemic candidiasis.1 Studies by Matthews et al2 indicated HSP90 fragments are major targets for the immune system in infection due to C. albicans, and anti-epitope LKVIRK of HSP90 antibody is a serological marker for diagnosis of invasive candidiasis. Cloning and sequencing HSP90 antigen revealed that the linear epitope LKVIRK, localized near the C-terminus of the 47 kDa protein which circulates in the sera of patients with invasive candidiasis, as a heat-stable breakdown product of large more heat-labile antigen HSP90.2 In this study, epitope LKVIRK was displayed on the surface of phage fd to develop a new serological test for systemic candidiasis.

  8. Humoral immunity links Candida albicans infection and celiac disease.

    Directory of Open Access Journals (Sweden)

    Marion Corouge

    Full Text Available 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.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.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.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.

  9. PENGHAMBATAN CAJUPUTS CANDY TERHADAP VIABILITAS KHAMIR Candida albicans SECARA IN VITRO [Inhibition of Cajuputs Candy Toward the Viability of Candida albicans by using In Vitro Assay

    Directory of Open Access Journals (Sweden)

    C. Hanny Wijaya1*

    2014-12-01

    Full Text Available The utilization of cajuput essential oil as a flavor in candy may produce a physiological active added value. Some compounds of cajuput plant (Melaleuca cajuputi L have been reported for their anti-microbial activities. Candida albicans is a normal commensal organism in human mouth. However, it may become virulent and responsible for oral diseases known as oral candidiasis. This study aimed to determine the effect of cajuput and peppermint oil in cajuputs candy in inhibiting the C. albicans biofilms formation by using in vitro biofilm assay and viability assay. Furthermore, the influence of concentration of cajuput oil on the anti-microbial activities had been analyzed. All the tested concentration of cajuput oil in cajuputs candy was effective to inhibit the viability of C. albicans. The provision of flavor components of cajuput and peppermint oil could produce synergistic effects compared to a single flavor component. The addition of cajuput oil at 0.6% was able to inhibit the viability of C. albicans. The activities of the cajuput oil showed positive correlation to the concentration. The variable of plus and minus 0.1% addition of the cajuput oil concentration, however, produced no significant difference to inhibit the growth of C. albicans in biofilm. Sensory test, hedonic test, was conducted to evaluate the flavor, aroma, and overall attributes, resulting in no significant difference between 0.6 to 0.8% additions of cajuput oil upon the sensory acceptance.

  10. Gene

    Data.gov (United States)

    U.S. Department of Health & Human Services — Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes,...

  11. Structure of the transcriptional network controlling white-opaque switching in Candida albicans.

    Science.gov (United States)

    Hernday, Aaron D; Lohse, Matthew B; Fordyce, Polly M; Nobile, Clarissa J; DeRisi, Joseph L; Johnson, Alexander D

    2013-10-01

    The human fungal pathogen Candida albicans can switch between two phenotypic cell types, termed 'white' and 'opaque'. Both cell types are heritable for many generations, and the switch between the two types occurs epigenetically, that is, without a change in the primary DNA sequence of the genome. Previous work identified six key transcriptional regulators important for white-opaque switching: Wor1, Wor2, Wor3, Czf1, Efg1, and Ahr1. In this work, we describe the structure of the transcriptional network that specifies the white and opaque cell types and governs the ability to switch between them. In particular, we use a combination of genome-wide chromatin immunoprecipitation, gene expression profiling, and microfluidics-based DNA binding experiments to determine the direct and indirect regulatory interactions that form the switch network. The six regulators are arranged together in a complex, interlocking network with many seemingly redundant and overlapping connections. We propose that the structure (or topology) of this network is responsible for the epigenetic maintenance of the white and opaque states, the switching between them, and the specialized properties of each state.

  12. Chitin synthetases in Candida albicans: a review on their subcellular distribution and biological function.

    Science.gov (United States)

    Martínez, J P; Gozalbo, D

    1994-09-01

    In the light of recent genetic advances, some results regarding chitin biosynthetic activities are reviewed in this paper. Genes coding for distinct enzymes displaying chitin synthetase activities have been characterized in Saccharomyces cerevisiae as well as in other fungal species including Candida albicans. Several activities seem to exist in the cells: (i) one zymogenic, located in cytoplasmic vesicles called chitosomes, although the presence of other types of vesicles with zymogenic activity cannot be completely discarded, and (ii) plasma membrane associated activities (the active enzyme and probably two distinct pools of zymogenic activity). Possible relationships between these activities, if any, remain to be determined. These multiplicity of enzymes is not surprising taking into account that chitin biosynthesis is required during very well defined temporal and spatial events of the cell cycle. A general repair function for one of the chitin biosynthetic activities is proposed as a possible salvage mechanism to warrant cell survival after wall damage has been caused, since chitin appears to be the most suitable polymer to carry out this function due to its particular physico-chemical properties.

  13. Optimal Production and Biochemical Properties of a Lipase from Candida albicans

    Directory of Open Access Journals (Sweden)

    Bo Yang

    2011-10-01

    Full Text Available Lipases from microorganisms have multi-faceted properties and play an important role in ever-growing modern biotechnology and, consequently, it is of great significance to develop new ones. In the present work, a lipase gene from Candida albicans (CaLIP10 was cloned and two non-unusual CUG serine codons were mutated into universal codons, and its expression in Pichia pastoris performed optimally, as shown by response surface methodology. Optimal conditions were: initial pH of culture 6.86, temperature 25.53 °C, 3.48% of glucose and 1.32% of yeast extract. The corresponding maximal lipolytic activity of CaLIP10 was 8.06 U/mL. The purified CaLIP10 showed maximal activity at pH 8.0 and 25 °C, and a good resistance to non-ionic surfactants and polar organic solvent was noticed. CaLIP10 could effectively hydrolyze coconut oil, but exhibited no obvious preference to the fatty acids with different carbon length, and diacylglycerol was accumulated in the reaction products, suggesting that CaLIP10 is a potential lipase for the oil industry.

  14. Optimal production and biochemical properties of a lipase from Candida albicans.

    Science.gov (United States)

    Lan, Dongming; Hou, Shulin; Yang, Ning; Whiteley, Chris; Yang, Bo; Wang, Yonghua

    2011-01-01

    Lipases from microorganisms have multi-faceted properties and play an important role in ever-growing modern biotechnology and, consequently, it is of great significance to develop new ones. In the present work, a lipase gene from Candida albicans (CaLIP10) was cloned and two non-unusual CUG serine codons were mutated into universal codons, and its expression in Pichia pastoris performed optimally, as shown by response surface methodology. Optimal conditions were: initial pH of culture 6.86, temperature 25.53 °C, 3.48% of glucose and 1.32% of yeast extract. The corresponding maximal lipolytic activity of CaLIP10 was 8.06 U/mL. The purified CaLIP10 showed maximal activity at pH 8.0 and 25 °C, and a good resistance to non-ionic surfactants and polar organic solvent was noticed. CaLIP10 could effectively hydrolyze coconut oil, but exhibited no obvious preference to the fatty acids with different carbon length, and diacylglycerol was accumulated in the reaction products, suggesting that CaLIP10 is a potential lipase for the oil industry.

  15. Perbandingan Daya Hambat Larutan Antiseptik Povidone iodine dengan Ekstrak Daun Sirih terhadap Candida albicans secara In Vitro

    Directory of Open Access Journals (Sweden)

    Septriana Putri

    2015-09-01

    Full Text Available Abstrak Candida albicansb (C. albicans adalah salah satu mikroorganisme penyebab masalah kesehatan reproduksi wanita, yaitu keputihan (fluor albus. Penggunaan larutan povidone iodine dan bahan alam seperti ekstrak daun sirih menjadi pilihan masyarakat sebagai pembersih alat kewanitaan. Tujuan penelitian ini adalah untuk membandingkandaya hambat larutan antiseptik povidone iodine dan ekstrak daun sirih terhadap jamur C. albicans secara in vitro. Penelitian dilakukan terhadap lima isolat jamur C. albicans dengan larutan kontrol akuades.Perlakuan terdiri dari povidone iodine, ekstrak daun sirih dengan konsentrasi 5%, 10%, dan 20%.Hasil penelitian menunjukkan bahwa povidone iodine memiliki daya hambat terhadap C. albicans. Ekstrak daun sirih dengan konsentrasi 5% dan 10% tidak memiliki daya hambat terhadap C. albicans, namun ekstrak daun sirih konsentrasi 20% memiliki daya hambat terhadap C. albicans. Analisis statistik dengan uji ANOVA yang dilanjutkan dengan uji Post-hoc menunjukkan perbedaan bermakna antara daya hambat larutan povidone iodine dan ekstrak daun sirih 20% terhadap kontrol(p < 0.05.Larutan povidone iodine memiliki daya hambat dua kali lebih besar terhadap pertumbuhan C. albicans dibandingkan ekstrak daun sirih 20%. Dari penelitian ini dapat disimpulkan bahwa larutan povidone iodine dan ekstrak daun sirih 20% dapat menghambat pertumbuhan jamur C. albicans secara in vitro. Kata kunci: povidone iodine, ekstrak daun sirih, Candida albicansAbstract Candida albicans (C. albicans is one of the frequent causes of  reproductive health problems in women, namely vaginal discharge (fluor albus. The antiseptic solution, povidone iodine, is still an option to overcome vaginal discharge. The use of natural materials such as betel (Piper betle L. leaves extract also become a popular choice as adouche for women. The objective of this study was to compare the inhibitory activity of povidone iodine solution and betel leaf extract against the growth of

  16. Functional genomics identifies type I interferon pathway as central for host defense against Candida albicans

    NARCIS (Netherlands)

    Smeekens, Sanne P.; Ng, Aylwin; Kumar, Vinod; Johnson, Melissa D.; Plantinga, Theo S.; van Diemen, Cleo; Arts, Peer; Verwiel, Eugene T. P.; Gresnigt, Mark S.; Fransen, Karin; van Sommeren, Suzanne; Oosting, Marije; Cheng, Shih-Chin; Joosten, Leo A. B.; Hoischen, Alexander; Kullberg, Bart-Jan; Scott, William K.; Perfect, John R.; van der Meer, Jos W. M.; Wijmenga, Cisca; Netea, Mihai G.; Xavier, Ramnik J.

    2013-01-01

    Candida albicans is the most common human fungal pathogen causing mucosal and systemic infections. However, human antifungal immunity remains poorly defined. Here by integrating transcriptional analysis and functional genomics, we identified Candida-specific host defence mechanisms in humans. Candid

  17. In Vitro Study on the Adhesion and Colonization of Candida Albicans on Metal and Acrylic Piercings

    Directory of Open Access Journals (Sweden)

    Stamenov N.

    2016-03-01

    Full Text Available Oral/perioral piercing may provide an ideal environment for adhesion and colonization of microorganisms. The aim of this study is to perform an “in vitro” research on the capabilities of adhesion of Candida albicans on oral piercings made of plastic and metal. Acrylic and metal piercings were incubated with Candida albicans and then were observed using scanning electron microscopy under different magnifications. A lot of irregularities and roughness were observed on the surface of the plastic piercing unlike the surface of the metal one, which is not so rough. Nevertheless, the number of Candida albicans colonies was considerably larger on the scanned metal surface in comparison to the plastic surface. In vitro the metal surface of the piercing creates better environment for the adhesion and colonization of microorganisms than the acrylic. This could be attributed to the electrostatic forces that most likely attract Candida albicans to the metal piercing in the early stages of biofilm formation.

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

    NARCIS (Netherlands)

    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; Shirtliff, Mark E.

    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

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

    Science.gov (United States)

    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 albicans, C. dubliniensis and C. metapsilosis.

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

    Institute of Scientific and Technical Information of China (English)

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

    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.

  1. Phenotypic aspects of oral strains of Candida albicans in children with down's syndrome

    Directory of Open Access Journals (Sweden)

    E. L. Ribeiro

    Full Text Available The aim of this article is to characterize the biological aspects of oral strains of C. albicans in children with Down's syndrome. These yeasts were analyzed as to their macromorphological and enzymatic aspects and were tested as to their in vitro susceptibility to antifungal drugs using broth microdilution to determine the minimum inhibitory concentration (MIC. The morphotyping revealed that all oral C. albicans isolates from children with Down's syndrome promoted the formation of fringes regardless of size, while the control group presented smaller fringes. All oral C. albicans strains produced proteinase, but those with phospholipolytic activity showed greater enzyme capacity in the test group. In vitro susceptibility showed that all oral C. albicans isolates were sensitive to the drugs used.

  2. In Vitro Effect of Local Anesthetics on Candida albicans Germ Tube Formation

    Directory of Open Access Journals (Sweden)

    Acácio Rodrigues

    1994-01-01

    Full Text Available Objective: This study was planned to clarify the in vitro effect of lidocaine and bupivacaine on germ tube formation by Candida albicans isolates from cases of clinical vaginal candidiasis.

  3. Candida albicans is not always the preferential yeast colonizing humans: a study in Wayampi Amerindians.

    Science.gov (United States)

    Angebault, Cécile; Djossou, Félix; Abélanet, Sophie; Permal, Emmanuelle; Ben Soltana, Mouna; Diancourt, Laure; Bouchier, Christiane; Woerther, Paul-Louis; Catzeflis, François; Andremont, Antoine; d'Enfert, Christophe; Bougnoux, Marie-Elisabeth

    2013-11-15

    In industrialized countries Candida albicans is considered the predominant commensal yeast of the human intestine, with approximately 40% prevalence in healthy adults. We discovered a highly original colonization pattern that challenges this current perception by studying in a 4- year interval a cohort of 151 Amerindians living in a remote community (French Guiana), and animals from their environment. The prevalence of C. albicans was persistently low (3% and 7% of yeast carriers). By contrast, Candida krusei and Saccharomyces cerevisiae were detected in over 30% of carriers. We showed that C. krusei and S. cerevisiae carriage was of food or environmental origin, whereas C. albicans carriage was associated with specific risk factors (being female and living in a crowded household). We also showed using whole-genome sequence comparison that C. albicans strains can persist in the intestinal tract of a healthy individual over a 4-year period.

  4. Differential virulence of Candida albicans and C. dubliniensis: A role for Tor1 kinase?

    LENUS (Irish Health Repository)

    Sullivan, Derek J

    2011-01-01

    Candida albicans and Candida dubliniensis are two very closely related species of pathogenic yeast. C. albicans is the most prevalent species in the human gastrointestinal tract and is responsible for far more opportunistic infections in comparison with C. dubliniensis. This disparity is likely to be due to the reduced ability of C. dubliniensis to undergo the yeast to hypha transition, a change in morphology that plays an important role in C. albicans virulence. We have recently shown that hypha formation by C. dubliniensis is specifically repressed by nutrients at alkaline pH. In this article, we present new data showing that this can be partly reversed by treatment with rapamycin, an inhibitor of the nutrient sensing kinase Tor1 (Target Of Rapamycin). We also provide a speculative model to describe why C. albicans filaments more efficiently in nutrient rich environments, citing recently described data on Mds3, a pH responsive regulator of Tor1 kinase activity.

  5. Lactobacillus acidophilus ATCC 4356 inhibits biofilm formation by C. albicans and attenuates the experimental candidiasis in Galleria mellonella.

    Science.gov (United States)

    Vilela, Simone F G; Barbosa, Júnia O; Rossoni, Rodnei D; Santos, Jéssica D; Prata, Marcia C A; Anbinder, Ana Lia; Jorge, Antonio O C; Junqueira, Juliana C

    2015-01-01

    Probiotic strains of Lactobacillus have been studied for their inhibitory effects on Candida albicans. However, few studies have investigated the effect of these strains on biofilm formation, filamentation and C. albicans infection. The objective of this study was to evaluate the influence of Lactobacillus acidophilus ATCC 4356 on C. albicans ATCC 18804 using in vitro and in vivo models. In vitro analysis evaluated the effects of L. acidophilus on the biofilm formation and on the capacity of C. albicans filamentation. For in vivo study, Galleria mellonella was used as an infection model to evaluate the effects of L. acidophilus on candidiasis by survival analysis, quantification of C. albicans CFU/mL, and histological analysis. The direct effects of L. acidophilus cells on C. albicans, as well as the indirect effects using only a Lactobacillus culture filtrate, were evaluated in both tests. The in vitro results showed that both L. acidophilus cells and filtrate were able to inhibit C. albicans biofilm formation and filamentation. In the in vivo study, injection of L. acidophilus into G. mellonella larvae infected with C. albicans increased the survival of these animals. Furthermore, the number of C. albicans CFU/mL recovered from the larval hemolymph was lower in the group inoculated with L. acidophilus compared to the control group. In conclusion, L. acidophilus ATCC 4356 inhibited in vitro biofilm formation by C. albicans and protected G. mellonella against experimental candidiasis in vivo.

  6. Lactobacillus acidophilus ATCC 4356 inhibits biofilm formation by C. albicans and attenuates the experimental candidiasis in Galleria mellonella

    Science.gov (United States)

    Vilela, Simone FG; Barbosa, Júnia O; Rossoni, Rodnei D; Santos, Jéssica D; Prata, Marcia CA; Anbinder, Ana Lia; Jorge, Antonio OC; Junqueira, Juliana C

    2015-01-01

    Probiotic strains of Lactobacillus have been studied for their inhibitory effects on Candida albicans. However, few studies have investigated the effect of these strains on biofilm formation, filamentation and C. albicans infection. The objective of this study was to evaluate the influence of Lactobacillus acidophilus ATCC 4356 on C. albicans ATCC 18804 using in vitro and in vivo models. In vitro analysis evaluated the effects of L. acidophilus on the biofilm formation and on the capacity of C. albicans filamentation. For in vivo study, Galleria mellonella was used as an infection model to evaluate the effects of L. acidophilus on candidiasis by survival analysis, quantification of C. albicans CFU/mL, and histological analysis. The direct effects of L. acidophilus cells on C. albicans, as well as the indirect effects using only a Lactobacillus culture filtrate, were evaluated in both tests. The in vitro results showed that both L. acidophilus cells and filtrate were able to inhibit C. albicans biofilm formation and filamentation. In the in vivo study, injection of L. acidophilus into G. mellonella larvae infected with C. albicans increased the survival of these animals. Furthermore, the number of C. albicans CFU/mL recovered from the larval hemolymph was lower in the group inoculated with L. acidophilus compared to the control group. In conclusion, L. acidophilus ATCC 4356 inhibited in vitro biofilm formation by C. albicans and protected G. mellonella against experimental candidiasis in vivo. PMID:25654408

  7. Control of Candida albicans metabolism and biofilm formation by Pseudomonas aeruginosa phenazines.

    Science.gov (United States)

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

    2013-01-29

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

  8. Contact-Free Inactivation of Candida albicans Biofilms by Cold Atmospheric Air Plasma

    OpenAIRE

    Maisch, Tim; Shimizu, Tetsuji; Isbary, Georg; Heinlin, Julia; Karrer, Sigrid; Klämpfl, Tobias G.; Li, Yang-Fang; Morfill, Gregor; Julia L Zimmermann

    2012-01-01

    Candida albicans is one of the main species able to form a biofilm on almost any surface, causing both skin and superficial mucosal infections. The worldwide increase in antifungal resistance has led to a decrease in the efficacy of standard therapies, prolonging treatment time and increasing health care costs. Therefore, the aim of this work was to demonstrate the applicability of atmospheric plasma at room temperature for inactivating C. albicans growing in biofilms without thermally damagi...

  9. Beneficial effects of Plantago albicans on high-fat diet-induced obesity in rats.

    Science.gov (United States)

    Samout, Noura; Ettaya, Amani; Bouzenna, Hafsia; Ncib, Sana; Elfeki, Abdelfattah; Hfaiedh, Najla

    2016-12-01

    Obesity is a one of the main global public health problems associated with chronic diseases such as coronary heart disease, diabetes and cancer. As a solution to obesity, we suggest Plantago albicans, which is a medicinal plant with several biological effects. This study assesses the possible anti-obesity protective properties of Plantago albicans in high fat diet-fed rats. 28 male Wistar rats were divided into 4 groups; a group which received normal diet (C), the second group was fed HDF diet (HDF), the third group was given normal diet supplemented with Plantago albicans (P.AL), and the fourth group received HDF supplemented with Plantago albicans (HDF+P.AL) (30mg/kg/day) for 7 weeks. Our results showed an increase in body weight of HDF rats by ∼16% as compared to the control group with an increase in the levels of total cholesterol (TC) as well as LDL-cholesterol, triglycerides (TG) in serum. Also, the concentration of TBARS increased in the liver and heart of HDF-fed rats as compared to the control group. The oral gavage of Plantago albicans extract to obese rats induced a reduction in their body weight, lipid accumulation in liver and heart tissue, compared to the high-fat diet control rats. The obtained results proved that the antioxidant potency of Plantago albicans extracts was correlated with their phenolic and flavonoid contents. The antioxidant capacity of the extract was evaluated by DPPH test (as EC50=250±2.12μg/mL) and FRAP tests (as EC50=27.77±0.14μg/mL). These results confirm the phytochemical and antioxidant impact of Plantago albicans extracts. Plantago albicans content was determined using validated HPLC methodology.

  10. Fungal inhibitory effect of Citrus Limon peel essential oil on Candida albicans

    Directory of Open Access Journals (Sweden)

    Iwan Hernawan

    2015-06-01

    Full Text Available Background: Oral candidiasis is an opportunistic infections due to Candida albicans that often found in people with HIV/AIDS. Anti-fungi, polyne and azole, are used in the treatment of oral candidiasis, but often cause persistence and recurrence. Citrus Limon peel contains terpenoids capable of inhibiting the synthesis of ergosterol, a component of the fungal cell wall that helps to maintain cell membrane permeability. Essential oil derived from citrus limon peel, thus, is expected to inhibit the growth of Candida albicans. Purpose: This research was aimed to know how essential oil derived from citrus Limon peel can inhibit the growth of Candida albicans. Method: This research was a laboratory experimental research carried out in three phases. First, essential oil was made with cold pressing method, and then the concentration of 100% was diluted to 50%, 12.5%, 6.25%, 3.125%, 1.56% and 0.78%. A test was conducted on the culture of Candida albicans in Sabouraud broth, accompanied by control (+ and (-. Second, the dilution of essential oil was conducted to alter the concentration with inhibitory power, from the strongest one to the weakest one, and then it was tested on the culture of Candida albicans. Third, spreading was carried out from liquid culture to agar media in order to measure the number of colonies. Result: Candida albicans did not grow on media with 100% essential oil treatment, but it grew on media with 50% essential oil treatment. In the second phase, dilution of 100%, 90%, 80%, 70%, 60% and 50% was conducted. The growth of Candida albicans was found on the treatment media of 60% and 50%. On the agar media, the growth occurred in the cultured medium treated with 70%. Conclusion: The minimum inhibitory power of essential oil derived from citrus Limon peel against Candida albicans was in the concentration of 80%. Essential oil derived from citrus Limon peel has antifungal effect and potential as a therapeutic agent for oral candidiasis.

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

    Science.gov (United States)

    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.

  12. Exopolysaccharide matrix of developed candida albicans biofilms after exposure to antifungal agents

    OpenAIRE

    2012-01-01

    This study aimed to evaluate the effects of fluconazole or nystatin exposure on developed Candida albicans biofilms regarding their exopolysaccharide matrix. The minimal inhibitory concentration (MIC) against fluconazole or nystatin was determined for C. albicans reference strain (ATCC 90028). Poly(methlymethacrylate) resin (PMMA) specimens were fabricated according to the manufacturer's instructions and had their surface roughness measured. Biofilms were developed on specimens surfaces for 4...

  13. Histatin 5 inhibits adhesion of C. albicans to Reconstructed Human Oral Epithelium.

    Science.gov (United States)

    Moffa, Eduardo B; Mussi, Maria C M; Xiao, Yizhi; Garrido, Saulo S; Machado, Maria A A M; Giampaolo, Eunice T; Siqueira, Walter L

    2015-01-01

    Candida albicans is the most pathogenic fungal species, commonly colonizing on human mucosal surfaces. As a polymorphic species, C. albicans is capable of switching between yeast and hyphal forms, causing an array of mucosal and disseminated infections with high mortality. While the yeast form is most commonly associated with systemic disease, the hyphae are more adept at adhering to and penetrating host tissue and are therefore frequently observed in mucosal fungal infections, most commonly oral candidiasis. The formation of a saliva-derived protein pellicle on the mucosa surface can provide protection against C. albicans on oral epithelial cells, and narrow information is available on the mucosal pellicle composition. Histatins are one of the most abundant salivary proteins and presents antifungal and antibacterial activities against many species of the oral microbiota, however, its presence has never been studied in oral mucosa pellicle. The objective of this study was to evaluate the potential of histatin 5 to protect the Human Oral Epithelium against C. albicans adhesion. Human Oral Epithelial Tissues (HOET) were incubated with PBS containing histatin 5 for 2 h, followed by incubation with C. albicans for 1 h at 37°C. The tissues were then washed several times in PBS, transferred to fresh RPMI and incubated for 16 h at 37°C at 5% CO2. HOET were then prepared for histopathological analysis using light microscopy. In addition, the TUNEL assay was employed to evaluate the apoptosis of epithelial cells using fluorescent microscopy. HOET pre-incubated with histatin 5 showed a lower rate of C. albicans growth and cell apoptosis when compared to the control groups (HOET alone and HOET incubated with C. albicans). The data suggest that the coating with histatin 5 is able to reduce C. albicans colonization on epithelial cell surfaces and also protect the basal cell layers from undergoing apoptosis.

  14. Antimicrobial activity of plant extracts on Candida albicans: An in vitro study

    OpenAIRE

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

    2013-01-01

    Background and Objectives: Plants as sources of medicinal compounds have continued to play a predominant role in the maintenance of human health since ancient times. Even though several effective antifungal agents are available for oral candida infections, the failure is not uncommon because isolates of Candida albicans may exhibits resistance to the drug during therapy. The present study was conducted to evaluate the antimicrobial effects of few plant extracts on Candida albicans. An additio...

  15. Candida albicans SUR7 contributes to secretion, biofilm formation, and macrophage killing

    Directory of Open Access Journals (Sweden)

    Bernardo Stella M

    2010-04-01

    Full Text Available Abstract Background Candida albicans SUR7 has been shown to be required for plasma membrane organization and cell wall synthesis, but its role in virulence is not known. Using a bioinformatics strategy, we previously identified several novel putative secretion pathway proteins potentially involved in virulence, including the C. albicans homolog of the Saccharomyces cerevisiae endocytosis-related protein Sur7p. We therefore generated a C. albicans sur7Δ null mutant and examined its contribution to key virulence attributes. Results Structurally, the C. albicans sur7Δ mutant was impaired in response to filamentation-inducing conditions, and formed aberrant hyphae with extensive accumulation of plasma membrane-derived structures within the cell. Absence of SUR7 resulted in a temperature-sensitive growth defect at high temperatures (42°C, which was partially rescued by addition of NaCl. We next examined the role of the SUR7 paralog C. albicans FMP45 in this temperature-sensitive phenotype. Analysis of C. albicans Fmp45p-GFP demonstrated co-localization of Fmp45p with Sur7p and increased fluorescence in the plasma membrane in the presence of high salt. We next focused on key virulence-related phenotypes. The C. albicans sur7Δ null mutant exhibited secretory defects: reduced lipase secretion, and increased levels of secreted Sap2p. The null mutant was hyper-susceptible to sub-inhibitory concentrations of caspofungin, but not amphotericin B and 5-fluorocytosine. Functionally, the sur7Δ mutant demonstrated increased adhesion to polystyrene and of note, was markedly defective in biofilm formation. In an in vitro macrophage model of virulence, the sur7Δ mutant was impaired in macrophage killing. Conclusions Plasma membrane and cell wall organization are important for cell morphology, and alterations of these structures contributed to impairment of several key virulence-associated phenotypes in the C. albicans sur7Δ mutant.

  16. A virtual infection model quantifies innate effector mechanisms and Candida albicans immune escape in human blood.

    Directory of Open Access Journals (Sweden)

    Kerstin Hünniger

    2014-02-01

    Full Text Available Candida albicans bloodstream infection is increasingly frequent and can result in disseminated candidiasis associated with high mortality rates. To analyze the innate immune response against C. albicans, fungal cells were added to human whole-blood samples. After inoculation, C. albicans started to filament and predominantly associate with neutrophils, whereas only a minority of fungal cells became attached to monocytes. While many parameters of host-pathogen interaction were accessible to direct experimental quantification in the whole-blood infection assay, others were not. To overcome these limitations, we generated a virtual infection model that allowed detailed and quantitative predictions on the dynamics of host-pathogen interaction. Experimental time-resolved data were simulated using a state-based modeling approach combined with the Monte Carlo method of simulated annealing to obtain quantitative predictions on a priori unknown transition rates and to identify the main axis of antifungal immunity. Results clearly demonstrated a predominant role of neutrophils, mediated by phagocytosis and intracellular killing as well as the release of antifungal effector molecules upon activation, resulting in extracellular fungicidal activity. Both mechanisms together account for almost [Formula: see text] of C. albicans killing, clearly proving that beside being present in larger numbers than other leukocytes, neutrophils functionally dominate the immune response against C. albicans in human blood. A fraction of C. albicans cells escaped phagocytosis and remained extracellular and viable for up to four hours. This immune escape was independent of filamentation and fungal activity and not linked to exhaustion or inactivation of innate immune cells. The occurrence of C. albicans cells being resistant against phagocytosis may account for the high proportion of dissemination in C. albicans bloodstream infection. Taken together, iterative experiment

  17. Efek Antijamur Minyak Atsiri Jahe Merah (Zingiber officinale Var. Rubrum terhadap Candida albicans

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    Hermina Karuna Atmaja

    2015-10-01

    Full Text Available The prevalence of Candida albicans infections is increasing in the society. Therefore, an effective and affordable antifungal drug with minimal side effect is needed. Ginger (Zingiber officinale is a traditional herb which has an antifungal effect in its volatile oil. Objective: To investigate antifungal effect of volatile oil from Zingiber officinale var rubrum against C. albicans in vitro, to determine the optimum concentration, and finally to determine the correlation between the various concentrations of the oil and the inhibition zone. Material and method: Strain C. albicans tested was obtained from the Department of Parasitology, Medical Faculty, University of Indonesia. Volatile oil of Zingiber officinale var. rubrum was produced from water and steam distillation of fresh ginger in BALLITRO, Bogor. Concentrations of the volatile oil used were 100%, 50%, 25%, 12,5% 6.25%, 3.125%, 1.56% and 0.78%. Methods used were colony counting and disk diffusion method (by using 6 mm blank disk. The specimens were divided into two groups, treatment group (C. albicans with application of volatile oil and control group (C. albicans without application of volatile oil. Result: There was a significant decrease in the amount of C. albicans colonies from 3.125% to 6.25% of concentration. The amount of C. albicans colonies at concentration 6.25% was also significantly lower than in the control group. Moreover, there was strong and positive correlation between the concentration of the volatile oil and the inhibition zone. Conclusion: Volatile oil from Zingiber officinale var. rubrum has an antifungal effect against C. albicans in vitro with optimum concentration at 6.25%. Increasing concentrations of the oil correlates with increasing inhibition zome.

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

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

    2014-01-01

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

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

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    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.

  20. Commensal Protection of Staphylococcus aureus against Antimicrobials by Candida albicans Biofilm Matrix

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    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

  1. Antimicrobial activity of plant extracts on Candida albicans: An in vitro study

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    Sunitha Jagalur Doddanna

    2013-01-01

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

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

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    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.

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

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    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.

  4. Commensal Protection of Staphylococcus aureus against Antimicrobials by Candida albicans Biofilm Matrix

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    Eric F. Kong

    2016-10-01

    Full Text Available 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.

  5. Oral candidosis by Candida albicans in normal and xerostomic mice Candidose oral por Candida albicans em camundongos normais e xerostômicos

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    Marilda Aparecida Gonçalves Totti

    2004-09-01

    Full Text Available The aim of this study was to analyze the effect of sialoadenectomy on the development of oral candidosis after one or four inoculations of Candida albicans. Initially, a suspension containing 10(8 cells/ml of C. albicans ATCC 36801 was prepared. Seventy-eight sialoadenectomized mice and a similar amount of mice with normal salivary flow received a single inoculation of C. albicans suspension. Another group with a similar number of mice received 4 inoculations. The control group consisted of 6 sialoadenectomized mice and 6 mice with normal salivary flow that were not inoculated with C. albicans. Candidosis development was studied histologically in the tongue of the animals 1, 2, 3, 5, and 8 days after inoculation and at 15-day intervals up to 165 days. According to the results obtained, it could be concluded that sialoadenectomy and a higher frequency of yeast inoculation influenced the presence and extension of candidosis lesions.O objetivo deste estudo foi analisar o efeito da sialoadenectomia sobre o desenvolvimento da candidose oral após uma ou quatro inoculações de Candida albicans. Inicialmente, uma suspensão contendo 10(8 células/ml de C. albicans ATCC 36801 foi preparada. Setenta e oito camundongos sialoadenectomizados e mesma quantidade de camundongos com fluxo salivar normal receberam uma única inoculação de suspensão de C. albicans. Outro grupo, com o mesmo número de camundongos, recebeu 4 inoculações. O grupo controle consistiu de 6 camundongos sialoadenectomizados e 6 com fluxo salivar normal que não foram inoculados com C. albicans. O desenvolvimento de candidose foi estudado histologicamente na língua dos animais em períodos de 1, 2, 3, 5 e 8 dias após a inoculação e em intervalos de 15 dias até 165 dias. De acordo com os resultados obtidos, conclui-se que a sialoadenectomia e uma maior freqüência de inoculação influenciaram na presença e extensão das lesões de candidose.

  6. Lactobacillus crispatus Modulates Vaginal Epithelial Cell Innate Response to Candida albicans

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    Niu, Xiao-Xi; Li, Ting; Zhang, Xu; Wang, Su-Xia; Liu, Zhao-Hui

    2017-01-01

    Background: Vulvovaginal candidiasis is caused by Candida albicans. The vaginal epithelium, as the first site of the initial stage of infection by pathogens, plays an important role in resisting genital tract infections. Moreover, lactobacilli are predominant members of the vaginal microbiota that help to maintain a normal vaginal microenvironment. Therefore, Lactobacillus crispatus was explored for its capacity to intervene in the immune response of vaginal epithelial cells VK2/E6E7 to C. albicans. Methods: We examined the interleukin-2 (IL-2), 4, 6, 8, and 17 produced by VK2/E6E7 cells infected with C. albicans and treated with L. crispatus in vitro. The capacity of L. crispatus to adhere to VK2/E6E7 and inhibit C. albicans growth was also tested by scanning electron microscopy (SEM) and adhesion experiments. Results: Compared with group VK2/E6E7 with C. albicans, when treated with L. crispatus, the adhesion of C. albicans to VK2/E6E7 cells decreased significantly by 52.87 ± 1.22%, 47.03 ± 1.35%, and 42.20 ± 1.55% under competition, exclusion, and displacement conditions, respectively. SEM revealed that the invasion of C. albicans into VK2/E6E7 cells was caused by induced endocytosis and active penetration. L. crispatus could effectively protect the cells from the virulence of hyphae and spores of C. albicans and enhance the local immune function of the VK2/E6E7 cells. The concentrations of IL-2, 6, and 17 were upregulated significantly (P < 0.01) and that of IL-8 were downregulated significantly (P < 0.01) in infected VK2/E6E7 cells treated with L. crispatus. The concentration of IL-4 was similar to that of the group VK2/E6E7 with C. albicans (24.10 ± 0.97 vs. 23.12 ± 0.76 pg/ml, P = 0.221). Conclusions: L. crispatus can attenuate the virulence of C. albicans, modulate the secretion of cytokines and chemokines, and enhance the immune response of VK2/E6E7 cells in vitro. The vaginal mucosa has a potential function in the local immune responses against

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

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    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.

  8. Effects of Rosmarinus officinalis essential oil on germ tube formation by Candida albicans isolated from denture wearers

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    Lurdete Maria Rocha Gauch; Fabíola Silveira-Gomes; Renata Antunes Esteves; Simone Soares Pedrosa; Ely Simone Cajueiro Gurgel; Alberto Cardoso Arruda; Silvia Helena Marques-da-Silva

    2014-01-01

    Introduction The aim of this study was to investigate the effects of Rosmarinus officinalis essential oil on germ tube formation by Candida albicans isolated from denture wearers. Methods Ten C. albicans isolates recovered from denture wearers were tested using 10% fetal bovine serum with or without 4% R. officinalis essential oil. Results The essential oil from R. officinalis completely inhibited germ tube formation in the investigated C. albicans isolates. Conclusions The results demo...

  9. Candida albicans interface infection after deep anterior lamellar keratoplasty

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    Mohammad Reza Sedaghat

    2012-01-01

    Full Text Available The clinical features of interface Candida keratitis after deep anterior lamellar keratoplasty (DALK, may imitate rejection or crystalline keratopathy. We report here an 18-year-old woman presented with red eye, 4 months after undergoing DALK. Slit lamp examination revealed keratic precipitates (KPs and cojunctival injection. She was prescribed corticosteroid treatment for endothelial rejection by another ophthalmologist because of misdiagnosis, but suffered a recurrence of symptoms after reduction of the corticosteroid treatment. At that time, she was referred to our office. The recurrence persisted despite antibiotic and antifungal therapies. Ten days after treatment with interface irrigation with amphotericin, the infiltration and hypopyon were resolved. Topical steroid was added after 3 months of antifungal monotherapy. Irrigant cultures confirmed the presence of Candida albicans. The corneal graft appeared semi-clear with no signs of infection at 17-month follow-up. We recommend a close follow-up and a timely intervention to prevent the need for more invasive treatment such as penetrating keratoplasty.

  10. Effects of Rosmarinus officinalis essential oil on germ tube formation by Candida albicans isolated from denture wearers

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    Lurdete Maria Rocha Gauch

    2014-06-01

    Full Text Available Introduction The aim of this study was to investigate the effects of Rosmarinus officinalis essential oil on germ tube formation by Candida albicans isolated from denture wearers. Methods Ten C. albicans isolates recovered from denture wearers were tested using 10% fetal bovine serum with or without 4% R. officinalis essential oil. Results The essential oil from R. officinalis completely inhibited germ tube formation in the investigated C. albicans isolates. Conclusions The results demonstrate that the essential oil of R. officinalis modulates C. albicans pathogenicity through its primary virulence factor (i.e., germ tube formation was suppressed.

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

    Science.gov (United States)

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

    2015-01-01

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

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

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    Sandra Gil-Alonso

    Full Text Available 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.

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

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

    2011-10-15

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

  14. Prevalence of Trichomonas vaginalis and Candida albicans among Brazilian Women of Reproductive Age

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    Glehn, Mateus De Paula; Ferreira, Lana Cristina Evangelista Sá; Da Silva, Hian Delfino Ferreira; Machado, Eleuza Rodrigues

    2016-01-01

    Introduction There are no studies assessing the simultaneous occurrence of Candida albicans (C. albicans) and Trichomonas vaginalis (T. vaginalis) in the primary health care in Brazil. Despite different conditions to establishment of each one, the co-detection of both has been reported by some authors in previous studies from other regions. Aim To compare the prevalence of T. vaginalis and C. albicans in correlation with associated variables. Materials and Methods A cross-sectional study conducted in a family health clinic in the Federal District of Brazil, between November 2014 and March 2015. Vaginal swabs were collected from 201 women of the reproductive age selected from women registered at the family health clinic. Minors and pregnant women were excluded. The rates of T. vaginalis and Candida albicans prevalence were evaluated with vaginal pH, the whiff test, sexual practices and other social and demographic variables. Difference between proportions was assessed by Z-Test. Results C. albicans was present in 20% of the women, while 16% of them had T. vaginalis. The simultaneous occurrence of the agents was found in 1.5%. Significant differences were found between prevalence rates for the variables race/skin colour, practice of anilingus and lifetime number of sexual partners. Conclusion The prevalence of T. vaginalis exceeds C.albicans among women with higher numbers of sexual partners. The prevalence of C. albicans was higher than T. vaginalis among white women and those who practice active and receptive anilingus. The simultaneous occurrence of the two microorganisms was uncommon. PMID:28050410

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

    Science.gov (United States)

    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.

  16. Novel insight into neutrophil immune responses by dry mass determination of Candida albicans morphotypes.

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    Ava Hosseinzadeh

    Full Text Available The common fungal pathogen Candida albicans has the ability to grow as a yeast or as a hypha and can alternate between these morphotypes. The overall biomass of both morphotypes increases with growth. However, only yeasts, but not hyphae, exist as discrete cellular entities. Multiplicity of infection (MOI is a useful parameter to determine the initial inoculum of yeasts for in vitro infection assays. Since the amount of hyphae is difficult to quantify, comparable starting conditions in such assays cannot be determined accurately for yeasts and hyphae using MOI. To circumvent this problem, we have established a set of correlation coefficients to convert fungal metabolic activity and optical density to dry mass. Using these correlations, we were able to accurately compare ROS production and IL-8 release by polymorphonuclear neutrophils upon infection with equal dry mass amounts of yeast and hyphal morphotypes. Neutrophil responses depended on the initial form of infection, irrespective of C. albicans wild-type yeasts transforming to hyphal growth during the assay. Infection with a high mass of live C. albicans yeasts resulted in lower neutrophil ROS and this decrease stems from efficient ROS detoxification by C. albicans without directly affecting the phagocyte ROS machinery. Moreover, we show that dead C. albicans induces significantly less ROS and IL-8 release than live fungi, but thimerosal-killed C. albicans were still able to detoxify neutrophil ROS. Thus, the dry mass approach presented in this study reveals neutrophil responses to different amounts and morphotypes of C. albicans and serves as a template for studies that aim to identify morphotype-specific responses in a variety of immune cells.

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

    Directory of Open Access Journals (Sweden)

    Jan Krause

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

  18. Differential association of fluconazole dose and dose/MIC ratio with mortality in patients with Candida albicans and non-albicans bloodstream infection.

    Science.gov (United States)

    Brosh-Nissimov, T; Ben-Ami, R

    2015-11-01

    Targeting fluconazole therapy to achieve predefined pharmacodynamic goals has been suggested as a means of optimizing the treatment of patients with candidaemia. However, data regarding species-specific dosing targets are inconclusive. We retrospectively analysed a cohort of 75 adult patients with Candida bloodstream infection (BSI) who received initial treatment with fluconazole for ≥48 h (36 Candida albicans and 39 non-albicans Candida (NAC)). Fluconazole dose, the dose/MIC ratio and the 24-h area under the concentration-time curve (AUC24)/MIC ratio were determined for each patient, and classification and regression tree analysis was used to determine breakpoints for significant interactions with 30-day survival. Both fluconazole exposure parameters and patient-related and disease-related variables were assessed in univariable and multivariable survival models. The crude 30-day mortality rate was 32% (44% and 21% for C. albicans and NAC, respectively). An average fluconazole dose of >200 mg/day, a dose/MIC ratio of >400 and an AUC24/MIC ratio of >400 were associated with a higher 30-day survival rate and better microbiological response in patients with C. albicans BSI but not in those with NAC BSI. Baseline chronic kidney disease was a risk factor for fluconazole underdosing and mortality. Severity of sepsis (Sequential Organ Failure Assessment score) was the only significant predictor of death in patients with NAC BSI. We conclude that, although pharmacodynamic target-directed fluconazole dosing may help to optimize outcomes for patients with C. albicans BSI, additional studies are needed to define the role of fluconazole in the treatment of NAC BSI.

  19. Comparison of microsatellite length polymorphism and multilocus sequence typing for DNA-Based typing of Candida albicans.

    Science.gov (United States)

    Garcia-Hermoso, Dea; Cabaret, Odile; Lecellier, Gael; Desnos-Ollivier, Marie; Hoinard, Damien; Raoux, Dorothée; Costa, Jean-Marc; Dromer, Françoise; Bretagne, Stéphane

    2007-12-01

    For genotyping Candida albicans isolates, two PCR-based methods have recently emerged: multilocus sequence typing (MLST), based on the sequence of selected genes, and microsatellite length polymorphism (MLP), based on the length of PCR products containing variable numbers of short DNA repeats. To compare the two methods in their abilities to differentiate and group C. albicans isolates, we selected 50 independent isolates collected at the National Reference Center for Mycoses and Antifungals. MLST typing was performed using sequencing of seven loci as described at (http://test1.mlst.net). The MLP method consisted of a single multiplex PCR testing three different loci. Dendrograms were constructed by the unweighted pair group cluster method with Euclidean metric for both methods. The correlation between the distance matrices was performed with a Mantel test tested with 1,000 random permutations. The sensitivity and specificity of the MLP typing system were determined after allocating MLST groups for the greater number of isolates of each distinct MLP group. The discriminatory power index was >0.99, and the distances between the isolates were highly correlated with both systems. The Mantel coefficient and the Pearson product-moment correlation coefficient were 35,699 and 0.32, respectively (P < or = 1.2 x 10(-6)). Using MLP, the average specificity and sensitivity of clustering compared to MLST were 83% and 73%, respectively, when the singletons were excluded. The two methods are similarly discriminatory and can be interchangeable depending on the objectives. MLP is less expensive and faster than MLST. However, MLST is currently more accurate and additional standardization is needed for MLP.

  20. Candida albicans modulates host defense by biosynthesizing the pro-resolving mediator resolvin E1.

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    Eric J Haas-Stapleton

    Full Text Available Candida albicans is an opportunistic fungal pathogen of humans that resides commensally on epithelial surfaces, but can cause inflammation when pathogenic. Resolvins are a class of anti-inflammatory lipids derived from omega-3 polyunsaturated fatty acids (PUFA that attenuate neutrophil migration during the resolution phase of inflammation. In this report we demonstrate that C. albicans biosynthesizes resolvins that are chemically identical to those produced by human cells. In contrast to the trans-cellular biosynthesis of human Resolvin E1 (RvE1, RvE1 biosynthesis in C. albicans occurs in the absence of other cellular partners. C. albicans biosynthesis of RvE1 is sensitive to lipoxygenase and cytochrome P450 monoxygenase inhibitors. We show that 10nM RvE1 reduces neutrophil chemotaxis in response to IL-8; 1nM RvE1 enhanced phagocytosis of Candida by human neutrophils, as well as intracellular ROS generation and killing, while having no direct affect on neutrophil motility. In a mouse model of systemic candidiasis, RvE1 stimulated clearance of the fungus from circulating blood. These results reveal an inter-species chemical signaling system that modulates host immune functions and may play a role in balancing host carriage of commensal and pathogenic C. albicans.

  1. A comprehensive Candida albicans PeptideAtlas build enables deep proteome coverage.

    Science.gov (United States)

    Vialas, Vital; Sun, Zhi; Reales-Calderón, Jose A; Hernáez, María L; Casas, Vanessa; Carrascal, Montserrat; Abián, Joaquín; Monteoliva, Lucía; Deutsch, Eric W; Moritz, Robert L; Gil, Concha

    2016-01-10

    To provide new and expanded proteome documentation of the opportunistically pathogen Candida albicans, we have developed new protein extraction and analysis routines to provide a new, extended and enhanced version of the C. albicans PeptideAtlas. Two new datasets, resulting from experiments consisting of exhaustive subcellular fractionations and different growing conditions, plus two additional datasets from previous experiments on the surface and the secreted proteomes, have been incorporated to increase the coverage of the proteome. High resolution precursor mass spectrometry (MS) and ion trap tandem MS spectra were analyzed with three different search engines using a database containing allele-specific sequences. This approach, novel for a large-scale C. albicans proteomics project, was combined with the post-processing and filtering implemented in the Trans Proteomic Pipeline consistently used in the PeptideAtlas project and resulted in 49,372 additional peptides (3-fold increase) and 1630 more proteins (1.6-fold increase) identified in the new C. albicans PeptideAtlas with respect to the previous build. A total of 71,310 peptides and 4174 canonical (minimal non-redundant set) proteins (4115 if one protein per pair of alleles is considered) were identified representing 66% of the 6218 proteins in the predicted proteome. This makes the new PeptideAtlas build the most comprehensive C. albicans proteomics resource available and the only large-scale one with detections of individual alleles.

  2. Dodonaea viscosa var. angustifolia Inhibits Germ Tube and Biofilm Formation by C. albicans

    Directory of Open Access Journals (Sweden)

    Serisha Devi Naicker

    2013-01-01

    Full Text Available The virulence factors of Candida albicans are germ tube and biofilm formation, adherence to host tissues, and production of hydrolytic enzymes. This study investigated the effect of Dodonaea viscosa var. angustifolia extract on the germ tube and biofilm formation of C. albicans. Serum containing the three subinhibitory concentrations of leaf extract was inoculated with C. albicans, incubated, and viewed under a light microscope. Number of cells with germ tube was recorded and the results were analysed using Scheffe test for pairwise comparison. Biofilms were grown on coverslips in the presence of plant extracts and processed for scanning electron microscopy (SEM. Planktonic cells were grown in the presence of plant extract for 6 h and processed for electron microscopy (TEM. The crude plant extract significantly (P<0.01 reduced the germ tube formation of C. albicans at 3.125 (85.36%, 1.56 (61.91%, and 0.78 mg/mL (26.27% showing a concentration dependent effect. SEM results showed concentration dependent reduction in biofilm and hyphae formation. TEM results showed that the plant extract caused damage to the cell wall and cell membrane. DVA extract has ability to reduce virulence of C. albicans by inhibiting germ tube and biofilm formation through damage to the cell wall. Therefore, it has therapeutic potential.

  3. Histatin 5 inhibits adhesion of C. albicans to Reconstructed Human Oral Epithelium

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    Eduardo Buozi Moffa

    2015-08-01

    Full Text Available As a polymorphic species, C. albicans is capable of switching between yeast and hyphal forms. While the yeast form is most commonly associated with systemic disease, the hyphae are more adept at adhering to and penetrating host tissue and are therefore frequently observed in mucosal fungal infections, most commonly oral candidiasis. The objective of this study was to evaluate the potential of Histatin 5 to protect the Human Oral Epithelium against C. albicans adhesion. Human Oral Epithelial Tissues (HOET were incubated with PBS containing histatin 5 for 2 h, followed by incubation with C. albicans for 1 h at 37 °C, after HOET were washed with PBS, transferred to fresh RPMI and incubated for 16 h at 37°C at 5 % CO2. HOET were then prepared for histopathological analysis using light microscopy. In addition, the TUNEL assay was employed to evaluate the apoptosis of epithelial cells using fluorescent microscopy. HOET pre-incubated with histatin-5 showed a lower rate of C. albicans growth and cell apoptosis when compared to the control groups. The data suggest that the coating with histatin-5 is able to reduce C. albicans colonization on epithelial cell surfaces and also protect the basal cell layers from undergoing apoptosis.

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

    Science.gov (United States)

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

    2016-03-01

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

  5. The Structure-Activity Relationship of Pterostilbene Against Candida albicans Biofilms

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    Dan-Dan Hu

    2017-02-01

    Full Text Available Candida albicans biofilms contribute to invasive infections and dramatic drug resistance, and anti-biofilm agents are urgently needed in the clinic. Pterostilbene (PTE is a natural plant product with potentials to be developed as an anti-biofilm agent. In this study, we evaluated the structure-activity relationship (SAR of PTE analogues against C. albicans biofilms. XTT (Sodium 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl-2H-tetrazolium-5-carboxanilide inner salt reduction assay was used to evaluate the activity of the analogues against C. albicans biofilms. Knowing that hyphal formation is essential for C. albicans biofilms, anti-hyphal assay was further carried out. By comparing a series of compounds tested in this study, we found that compounds with para-hydroxy (–OH in partition A exhibited better activity than those with other substituents in the para position, and the double bond in partition B and meta-dimethoxy (–OCH3 in partition C both contributed to the best activity. Consistent results were obtained by anti-hyphal assay. Collectively, para-hydroxy (–OH, double bond and meta-dimethoxy (–OCH3 are all needed for the best activity of PTE against C. albicans biofilms.

  6. Genotype comparisons of strains of Candida albicans from patients with cutaneous candidiasis and vaginal candidiasis

    Institute of Scientific and Technical Information of China (English)

    SHE Xiao-dong; WANG Xue-jun; FU Mei-hua; SHEN Yong-nian; LIU Wei-da

    2008-01-01

    Background It is uncertain whether genotypes of Candida albicans (C. Albicans) are associated with colonizing body locations or variant conditions of infection. The aim of this study was to investigate whether there are significant associations between strain genotypes and body sites of infection and to determine the potential pathogenesis of cutaneous candidiasis at multiple locations.Methods A total of 151 strains of C. Albicans were isolated from 74 infant patients with cutaneous candidiasis and 61 female patients with vaginal candidiasis. Patients were grouped according to the body sites and underlying conditions of infection. Genolypes were identified by polymerase chain reaction (PCR) of the 25S rDNA and PCR-restriction fragment length polymorphism (RFLP) of ALT repeals digested with EcoRI and Clal.Results Ten genotypes were detected. There were significant differences in genotype frequencies between the two groups. However, we found no clear association between genotypes and the sites of cutaneous infection or the underlying conditions of vaginal candidiasis (VVC). In addition, strains of C. Albicans from multiple cutaneous locations of the same patient had identical genotypes.Conclusions Populations of C. Albicans from patients with cutaneous and vaginal candidiasis were genetically different. However, the lack of genetic difference between strains from different body sites with cutaneous infections or from different underlying conditions for VVC suggests no evidence of genotype selection for different skin surfaces or patients with different underlying conditions for VVC.

  7. Antifungal Activity of Lavandula Angustifolia and Quergues Infectoria Extracts in Comparison with Nystatin on Candida Albicans

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    F. Nouri

    2016-07-01

    Full Text Available Introduction & Objective: Nowadays,herbal extracts are used to treat diseases, especially infec-tious ones. Candida albicans is the most common causes of oral opportunistic infections.In this study, antifungal effects of two herbal extracts were evaluated on an oral pathogen i.e. Candida albicans. Materials & Methods: In this descriptive- analytic study, the Department of Prosthodontics, ,Tehran University of Medical Sciences, school of Dentistry the oral samples of 25 patients with denture stomatitis were collected using sterile swabs. Then the isolated candida albicans and standard candida albicans PTCC 5027 were cultured. The antifungal effect was evaluated with disk plate method. Nystatin and methanol were used as positive and negative control groups, respectively. The power of antifungal activity was evaluated with the inhibition zone diameter of each of the extracts. At the end, the data were analyzed by ANOVA and Fried-man statistical tests. Results: Results showed that extracts of Querques infectoria had great antifungal effects. There was not statistically significant difference between nystatine and Querques infectoria extract (P>0.05 however , Querques infectoria was statistically more effective than lavender extract and nystatin showed the highest antifungal activity (P <0.001. Conclusion: This study showed that plant extracts had positive effects on Candida albicans as compared to nystatin. Thus, we hope to find new herbal medicines and compounds to treat candidiasis in the future. (Sci J Hamadan Univ Med Sci 2016; 23 (2:172-178

  8. Microsatellite-based genotyping of Candida albicans isolated from patients with superficial candidiasis.

    Science.gov (United States)

    Shimizu, Kazue; Hattori, Hisao; Adachi, Hidesada; Oshima, Ryosuke; Horii, Toshinobu; Tanaka, Reiko; Yaguchi, Takashi; Tomita, Yasushi; Akiyama, Masashi; Kawamoto, Fumihiko; Kanbe, Toshio

    2011-01-01

    This study aimed to examine the genotype distribution of Candida albicans and the major genotypes involved in superficial candidiasis. The genotypes of C. albicans isolated from the infection sites of patients with superficial candidiasis (referred to as infection isolates) were analyzed by fragment analysis using 4 microsatellite markers (HIS3, CDC3, CAI and CAIII). Genotypes of the infection isolates were compared with those of C. albicans isolated from oral mucosa of non-candidiasis patients (referred to as oral isolates). Isolates of C. albicans showed 4 major genotypes for HIS3/CAI (" a " for 148 : 148 / 23 : 23," b " for 148 : 160 / 33 : 41," c " for 148 : 164 / 32 : 41 and " d " for 152 : 152 / 18 : 27). The genotypes " a "," b " and " d " were commonly found in oral (4.7, 8.8 and 7.6%, respectively) and infection (6.6, 9.2 and 15.4%, respectively) isolates. No isolates of genotype " c " were isolated from infection sites. The genotype " a " was found in the isolates from patients with genitalia candidiasis. Genotyping of multiple isolates from an individual patient showed that C. albicans from infection sites was genetically homogenous as compared with that of oral isolates, even in the same patient with candidiasis.

  9. Effects of carbapenems and their combination with amikacin on murine gut colonisation by Candida albicans.

    Science.gov (United States)

    Samonis, George; Galanakis, Emmanouil; Ntaoukakis, Markos; Sarchianaki, Emmanouela; Spathopoulou, Thomai; Dimopoulou, Dimitra; Kofteridis, Diamantis P; Maraki, Sofia

    2013-03-01

    Carbapenems are broad-spectrum antibiotics increasingly used for the treatment of severe infections. We evaluated the effects of four carbapenems given as monotherapies or in combination with amikacin on the level of gastrointestinal colonisation by Candida albicans in a previously established mouse model. Adult male Crl : CD1 (ICR) BR mice were fed chow containing C. albicans or regular chow. The mice fed with Candida chow had their gut colonised by the yeast. Both groups were subsequently given imipenem, meropenem, ertapenem, doripenem or their combination with amikacin or normal saline subcutaneously for 10 days. Stool cultures were performed immediately before, at the end and 1 week after discontinuation of treatment. Candida-colonised mice treated with the antibiotics had higher counts of the yeast in their stools than control C. albicans-colonised animals treated with saline. All four carbapenems and their combination with amikacin caused a significant increase in C. albicans concentration. Mice fed regular chow and treated with the study antibiotics or saline did not have any Candida in their stools. Dissemination of Candida was not detected in any animal. These data suggest that carbapenems and carbapenem plus amikacin induce substantial increases in the murine intestinal concentration of C. albicans.

  10. Candida albicans biofilm inhibition by synergistic action of terpenes and fluconazole.

    Science.gov (United States)

    Pemmaraju, Suma C; Pruthi, Parul A; Prasad, R; Pruthi, Vikas

    2013-11-01

    The current treatment options for Candida albicans biofilm-device related infections are very scarce due to their intrinsic increased tolerance to antimycotics. The aim of this work was to study synergistic action of terpenes (eugenol, menthol and thymol) with fluconazole (FLA) on C. albicans biofilm inhibition. The minimum inhibitory concentration (MIC) assayed using CLSI M27-A3 broth micro-dilution method showed antifungal activity against C. albicans MTCC 227 at a concentration of 0.12 % (v/v) for both thymol and eugenol as compared to 0.25 % (v/v) for menthol. FLA was taken as positive control. The effect of these terpenes on metabolic activity of preformed C. albicans biofilm cells was evaluated using 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay in 96-well polystyrene microtiter plate. Thymol and eugenol were more effective at lower concentrations of > or = 1.0 % (v/v) than menthol. Synergistic studies using checkerboard micro-dilution assay showed fractional inhibitory concentration index (sigma FIC = 0.31) between thymol/FLA followed by eugenol/FLA (sigma FIC = 0.37) and menthol/FLA (sigma FIC terpenes with fluconazole on C. albicans biofilm, which could be future medications for biofilm infections.

  11. Quantitative assessment of S. mutans and C. albicans in patients with Haas and Hyrax expanders

    Directory of Open Access Journals (Sweden)

    Matheus Melo Pithon

    2012-06-01

    Full Text Available OBJECTIVE: To assess and compare the number of Streptococcus mutans and Candida albicans colonies in patients with Haas and Hyrax appliances before and after insertion. METHODS: The sample consisted of 84 patients requiring orthodontic treatment. For all patients a midpalatal suture expansion was indicated. Patients were randomly divided into Group HA, who used the Haas appliance (n = 42 and Group HY, who used the Hyrax appliance (n = 42. Initially and thirty days after appliance insertion all patients were submitted to saliva collections. The saliva was diluted followed by seeding in Mitis Salivarius and CHROMagar media, for growth of S. mutans and C. albicans respectively. RESULTS: Results showed statistically significant difference between groups HA and HY for Streptococcus mutans and Candida albicans (p <0.05. Haas appliance promoted greater S. mutans and C. albicans proliferation when compared to Hyrax appliance. CONCLUSION: The Haas appliance favored greater proliferation of S. mutans and C. albicans when compared with the Hyrax appliance. Insertion of the appliances resulted in greater buildup of microorganisms.

  12. Adherence of Streptococcus mutans and Candida albicans to different bracket materials

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    Shrinivaasan Nambi Rammohan

    2012-01-01

    Full Text Available Objective: To quantify the adherence of Streptococcus mutans and Candida albicans on brackets made of stainless steel, plastic, ceramic, titanium, and gold, and to evaluate the various sites of adherence of these microorganisms with scanning electron microscopy (SEM. Materials and Methods: Brackets made of stainless steel, plastic, ceramic, titanium, and gold were used. The adherence of S. mutans and C. albicans were studied. The brackets were placed in flat-bottomed vials containing basal medium with 20% sucrose added; the flasks were inoculated with each of the microbial suspensions. The samples were incubated at 37°C for 48 h, after which the brackets were removed. The cells adhering to the glass were counted and the brackets were studied with SEM. Results: When evaluated together, the adherence of S. mutans and C. albicans was increased in the ceramic bracket group. When evaluated separately, metallic brackets had increased number of colony-forming units (CFUs of S. mutans and the use of titanium brackets increased the CFUs of C. albicans. SEM demonstrated that the adherence of S. mutans and C. albicans together varied according to the bracket materials, with ceramic having the greatest and stainless steel having the least adherence. Conclusions: Oral hygiene may be of greater concern with esthetic brackets since this study shows that microbial adhesion is greater with these brackets.

  13. Mapping of functional domains and characterization of the transcription factor Cph1 that mediate morphogenesis in Candida albicans.

    Science.gov (United States)

    Maiti, Protiti; Ghorai, Priyanka; Ghosh, Sumit; Kamthan, Mohan; Tyagi, Rakesh Kumar; Datta, Asis

    2015-10-01

    Cph1, a transcription factor of the Mitogen Activated Protein (MAP) kinase pathway, regulates morphogenesis in human fungal pathogen Candida albicans. Here, by following a systemic deletion approach, we have identified functional domains and motifs of Cph1 that are involved in transcription factor activity and cellular morphogenesis. We found that the N-terminal homeodomain is essential for the DNA binding activity; however, C-terminal domain and polyglutamine motif (PQ) are indispensable for the transcriptional activation function. Complementation analysis of the cph1Δ null mutant using various deletion derivatives revealed functional significance of the N- and C-terminal domains and PQ motif in filamentation process, chlamydospore formation and sensitivity to the cell wall interfering compounds. Genome-wide identification of the Cph1 binding site and quantitative RT-PCR transcript analysis in cph1Δ null mutant revealed that a number of genes which are associated with the filamentous growth, maintaining cell wall organization and mitochondrial function, and the genes of the pH response pathway are the transcriptional targets of Cph1. The data also suggest that Cph1 may function as a positive or negative regulator depending on the morphological state and physiological conditions. Moreover, differential expression of the upstream MAP kinase pathway genes in wild type and cph1Δ null mutant indicated the existence of a feedback regulation.

  14. Candida albicans and non-C. albicans Candida species: comparison of biofilm production and metabolic activity in biofilms, and putative virulence properties of isolates from hospital environments and infections.

    Science.gov (United States)

    Ferreira, A V; Prado, C G; Carvalho, R R; Dias, K S T; Dias, A L T

    2013-04-01

    Candida albicans and, more recently, non-C. albicans Candida spp. are considered the most frequent fungi in hospitals. This study analyzed Candida spp. isolates and compared the frequency of different species, that is, C. albicans and non-C. albicans Candida spp., and the origins of isolates, that is, from hospital environments or infections. Yeast virulence factors were evaluated based on biofilm production and metabolic activity. Hemolysin production and the antifungal susceptibility profiles of isolates were also evaluated. Candida spp. were highly prevalent in samples collected from hospital environments, which may provide a reservoir for continuous infections with these yeasts. There were no differences in the biofilm productivity levels and metabolic activities of the environmental and clinical isolates, although the metabolic activities of non-C. albicans Candida spp. biofilms were greater than those of the C. albicans biofilms (p albicans Candida spp. predominated in samples collected from hospital environments and infections (p albicans, which may explain the increased incidence of fungal infections with these yeasts during recent years.

  15. Protocol for Determination of the Persister Subpopulation in Candida Albicans Biofilms.

    Science.gov (United States)

    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.

  16. Myeloperoxidase-deficient zebrafish show an augmented inflammatory response to challenge with Candida albicans.

    Science.gov (United States)

    Wang, Kun; Fang, Xiao; Ma, Ning; Lin, Qing; Huang, Zhibin; Liu, Wei; Xu, Mengchang; Chen, Xiaohui; Zhang, Wenqing; Zhang, Yiyue

    2015-05-01

    Myeloperoxidase is a key component of neutrophil granules involved in killing engulfed microorganisms. We obtained a zebrafish mutant (smu681) lacking Sudan black staining by large-scale screening, which was a neutrophil-replete but myeloperoxidase-deficient mutant. When infiltrated with Candida albicans, smu681 embryos and sibling embryos showed similar survival after infection. Proliferation of C. albicans was more rapid in smu681 embryos than in sibling embryos, although it was eventually suppressed. In addition, the number of neutrophils accumulating at the site of infection was significantly larger in mutant embryos than in sibling embryos, and mutant embryos showed increased expression of several inflammatory cytokines after C. albicans infection. These findings indicate that myeloperoxidase deficiency alters the inflammatory response to fungal infection.

  17. A sticky situation: untangling the transcriptional network controlling biofilm development in Candida albicans.

    Science.gov (United States)

    Fox, Emily P; Nobile, Clarissa J

    2012-01-01

    Candida albicans is a commensal microorganism of the human microbiome; it is also the most prevalent fungal pathogen of humans. Many infections caused by C. albicans are a direct consequence of its proclivity to form biofilms--resilient, surface-associated communities of cells where individual cells acquire specialized properties that are distinct from those observed in suspension cultures. We recently identified the transcriptional network that orchestrates the formation of biofilms in C. albicans. These results set the stage for understanding how biofilms are formed and, once formed, how the specialized properties of biofilms are elaborated. This information will provide new insight for understanding biofilms in more detail and may lead to improvements in preventing and treating biofilm-based infections in the future.

  18. Antifungal Activity of Coumarin from Ageratum conyzoides L. Leaves on Candida albicans cells

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    Gunawan Pamudji Widodo

    2012-07-01

    Full Text Available The aim of this study was to identify the antifungal activity of coumarin isolated from Ageratum conyzoides L. leaves and to observe its influence on Candida albicans cells by scanning electron microscope (SEM and transmission electron microscope (TEM. Antifungal activity testing by disk diffusion method showed coumarin was active toward pathogenic fungus, Candida albicans with the MIC value of coumarin of 125 g mL-1. The influence of this substance on C. albicans cells was observed by scanning and transmission electron microscopies. The result showed that this compound damaged the cell by pores formation on the cell wall. The death of cells occurred due to leakage and necrotic of cytoplasmic content.

  19. Complement plays a central role in Candida albicans-induced cytokine production by human PBMCs

    DEFF Research Database (Denmark)

    Cheng, Shih-Chin; Sprong, Tom; Joosten, Leo A B

    2012-01-01

    In experimental studies, the role of complement in antifungal host defense has been attributed to its opsonizing capability. In this study, we report that in humans an activated complement system mainly augments Candida albicans-induced host proinflammatory cytokine production via C5a-C5a......R signaling, while phagocytosis and intracellular killing of Candida are not influenced. By blocking the C5a-C5aR signaling pathway, either with anti-C5a antagonist antibodies or with the C5aR antagonist W-54001, C. albicans-induced IL-6 and IL-1β levels were significantly reduced. Recombinant C5a augmented...... in augmenting host proinflammatory cytokine production upon contact with C. albicans, and define the role of the complement system in anti-Candida host defense in humans....

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

    Science.gov (United States)

    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.

  1. Oral Immunization Against Candidiasis Using Lactobacillus casei Displaying Enolase 1 from Candida albicans.

    Science.gov (United States)

    Shibasaki, Seiji; Karasaki, Miki; Tafuku, Senji; Aoki, Wataru; Sewaki, Tomomitsu; Ueda, Mitsuyoshi

    2014-01-01

    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.

  2. Growth of Candida albicans cells on the physiologically relevant carbon source lactate affects their recognition and phagocytosis by immune cells

    NARCIS (Netherlands)

    Ene, I.V.; Cheng, S.C.; Netea, M.G.; Brown, A.J.

    2013-01-01

    Candida albicans is a normal resident of the human gastrointestinal and urogenital tracts and also a prevalent fungal pathogen. During both commensalism and infection, it must match the immunological defenses of its host while adapting to environmental cues and the local nutrient status. C. albicans

  3. Comparison of virulence factors of oral Candida dubliniensis and Candida albicans isolates in healthy people and patients with chronic candidosis.

    Science.gov (United States)

    Hannula, J; Saarela, M; Dogan, B; Paatsama, J; Koukila-Kähkölä, P; Pirinen, S; Alakomi, H L; Perheentupa, J; Asikainen, S

    2000-08-01

    We determined differences in the expression of certain virulence factors between oral Candida dubliniensis and Candida albicans species. In addition, clonal differences were sought among C. albicans isolates recovered from patients with and without compromised immune system. The material comprised 93 clinical yeast isolates originated in 40 subjects (1-5 isolates per subject). All 26 C. dubliniensis isolates and 46 C. albicans isolates originated from healthy routine dental clinic patients. Additionally, 21 C. albicans isolates were collected from patients with autoimmune polyendocrinopathy-candidosis-ectodermal dystrophy (APECED), who have chronic candidosis as one manifestation of their immunocompromising disease. Polymerase chain reaction amplification using the random sequence primer OPE-03 enabled grouping of the C. dubliniensis isolates in 2 genotypes (I and II) and C. albicans isolates in 15 genotypes (I-XV). No significant difference was found in the distribution of genotypes between the patients with APECED and the healthy subjects. C. dubliniensis isolates exhibited high-frequency phenotypic switching significantly more frequently than did C. albicans isolates, and vice versa regarding phospholipase and proteinase production. Proteinase production was significantly more frequent among C. albicans genotype V than genotype IX isolates. No significant difference was found in expression of virulence factors of C. albicans isolates between the patients with APECED and the healthy subjects.

  4. Human antimicrobial peptide LL-37 inhibits adhesion of Candida albicans by interacting with yeast cell-wall carbohydrates.

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    Pei-Wen Tsai

    Full Text Available Candida albicans is the major fungal pathogen of humans. Fungal adhesion to host cells is the first step of mucosal infiltration. Antimicrobial peptides play important roles in the initial mucosal defense against C. albicans infection. LL-37 is the only member of the human cathelicidin family of antimicrobial peptides and is commonly expressed in various tissues and cells, including epithelial cells of both the oral cavity and urogenital tract. We found that, at sufficiently low concentrations that do not kill the fungus, LL-37 was still able to reduce C. albicans infectivity by inhibiting C. albicans adhesion to plastic surfaces, oral epidermoid OECM-1 cells, and urinary bladders of female BALB/c mice. Moreover, LL-37-treated C. albicans floating cells that did not adhere to the underlying substratum aggregated as a consequence of LL-37 bound to the cell surfaces. According to the results of a competition assay, the inhibitory effects of LL-37 on cell adhesion and aggregation were mediated by its preferential binding to mannan, the main component of the C. albicans cell wall, and partially by its ability to bind chitin or glucan, which underlie the mannan layer. Therefore, targeting of cell-wall carbohydrates by LL-37 provides a new strategy to prevent C. albicans infection, and LL-37 is a useful, new tool to screen for other C. albicans components involved in adhesion.

  5. Influence of aeration of Candida albicans during culturing on their surface aggregation in the presence of adhering Streptococcus gordonii

    NARCIS (Netherlands)

    Millsap, KW; van der Mei, HC; Busscher, HJ; Bos, R.R.M.

    1999-01-01

    Candida albicans surfaces are extremely sensitive to changes in growth conditions. In this study, adhesion to glass of aerated and non-aerated C. albicans ATCC 10261 in the presence and absence of adhering Streptococcus gordonii NCTC 7869 was determined in a parallel plate flow chamber. In addition,

  6. Effects of Low-Level Laser Irradiation on the Pathogenicity of Candida albicans: In Vitro and in Vivo Study

    NARCIS (Netherlands)

    Seyedmousavi Tasieh, S.; Hashemi, S.J.; Rezaie, S.; Fateh, M.; Djavid, G.E.; Zibafar, E.; Morsali, F.; Zand, N.; Alinaghizadeh, M.; Ataie-Fashtami, L.

    2014-01-01

    Abstract Objective: The purpose of this study was to evaluate the effects of low-level laser irradiation (LLLI) on the in vitro growth characteristics and in vivo pathogenicity of Candida albicans in a murine model in the absence of a photosensitizer. Background data: C. albicans is an opportunistic

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

    Science.gov (United States)

    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 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 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.

  8. Induction of ERK-kinase signalling triggers morphotype-specific killing of Candida albicans filaments by human neutrophils.

    Science.gov (United States)

    Wozniok, Iwona; Hornbach, Anke; Schmitt, Corinna; Frosch, Matthias; Einsele, Hermann; Hube, Bernhard; Löffler, Jürgen; Kurzai, Oliver

    2008-03-01

    Candida albicans is among the most important fungal pathogens in humans. Morphological plasticity has been linked to its pathogenic potential as filamentous forms are associated with tissue invasion and infection. Here we show that human neutrophils discriminate between yeasts and filaments of C. albicans. Whereas filaments induced targeted motility, resulting in the establishment of close contact between neutrophils and fungal cells, yeast forms were largely ignored during coincubation. In transwell assays, C. albicans filaments induced significantly higher migratory activity in neutrophils than yeasts. Neutrophil motility based on actin rearrangement was essential for killing of C. albicans filaments but not involved in killing of yeast forms. Using inhibitors for MAP-kinase cascades, it was shown that recognition of C. albicans filaments by neutrophils is mediated via the MEK/ERK cascade and independent of JNK or p38 activation. Inhibition of the ERK signalling pathway abolished neutrophil migration induced by C. albicans filaments and selectively impaired the ability to kill this morphotype. These data show that invasive filamentous forms of C. albicans trigger a morphotype-specific activation of neutrophils, which is strongly dependent on neutrophil motility. Therefore, human neutrophils are capable of sensing C. albicans invasion and initiating an appropriate early immune response.

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

    Science.gov (United States)

    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.

  10. The transcription factor Ndt80 does not contribute to Mrr1-, Tac1-, and Upc2-mediated fluconazole resistance in Candida albicans.

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    Christoph Sasse

    Full Text Available The pathogenic yeast Candida albicans can develop resistance to the widely used antifungal agent fluconazole, which inhibits ergosterol biosynthesis, by the overexpression of genes encoding multidrug efflux pumps or ergosterol biosynthesis enzymes. Zinc cluster transcription factors play a central role in the transcriptional regulation of drug resistance. Mrr1 regulates the expression of the major facilitator MDR1, Tac1 controls the expression of the ABC transporters CDR1 and CDR2, and Upc2 regulates ergosterol biosynthesis (ERG genes. Gain-of-function mutations in these transcription factors result in constitutive overexpression of their target genes and are responsible for fluconazole resistance in many clinical C. albicans isolates. The transcription factor Ndt80 contributes to the drug-induced upregulation of CDR1 and ERG genes and also binds to the MDR1 and CDR2 promoters, suggesting that it is an important component of all major transcriptional mechanisms of fluconazole resistance. However, we found that Ndt80 is not required for the induction of MDR1 and CDR2 expression by inducing chemicals. CDR2 was even partially derepressed in ndt80Δ mutants, indicating that Ndt80 is a repressor of CDR2 expression. Hyperactive forms of Mrr1, Tac1, and Upc2 promoted overexpression of MDR1, CDR1/CDR2, and ERG11, respectively, with the same efficiency in the presence and absence of Ndt80. Mrr1- and Tac1-mediated fluconazole resistance was even slightly enhanced in ndt80Δ mutants compared to wild-type cells. These results demonstrate that Ndt80 is dispensable for the constitutive overexpression of Mrr1, Tac1, and Upc2 target genes and the increased fluconazole resistance of strains that have acquired activating mutations in these transcription factors.

  11. Melanocytes and melanin represent a first line of innate immunity against Candida albicans.

    Science.gov (United States)

    Tapia, Cecilia V; Falconer, Maryanne; Tempio, Fabián; Falcón, Felipe; López, Mercedes; Fuentes, Marisol; Alburquenque, Claudio; Amaro, José; Bucarey, Sergio A; Di Nardo, Anna

    2014-07-01

    Melanocytes are dendritic cells located in the skin and mucosae that synthesize melanin. Some infections induce hypo- or hyperpigmentation, which is associated with the activation of Toll-like receptors (TLRs), especially TLR4. Candida albicans is an opportunist pathogen that can switch between blastoconidia and hyphae forms; the latter is associated with invasion. Our objectives in this study were to ascertain whether C. albicans induces pigmentation in melanocytes and whether this process is dependent on TLR activation, as well as relating this with the antifungal activity of melanin as a first line of innate immunity against fungal infections. Normal human melanocytes were stimulated with C. albicans supernatants or with crude extracts of the blastoconidia or hyphae forms, and pigmentation and TLR2/TLR4 expression were measured. Expression of the melanosomal antigens Melan-A and gp100 was examined for any correlation with increased melanin levels or antifungal activity in melanocyte lysates. Melanosomal antigens were induced earlier than cell pigmentation, and hyphae induced stronger melanization than blastoconidia. Notably, when melanocytes were stimulated with crude extracts of C. albicans, the cell surface expression of TLR2/TLR4 began at 48 h post-stimulation and peaked at 72 h. At this time, blastoconidia induced both TLR2 and TLR4 expression, whereas hyphae only induced TLR4 expression. Taken together, these results suggest that melanocytes play a key role in innate immune responses against C. albicans infections by recognizing pathogenic forms of C. albicans via TLR4, resulting in increased melanin content and inhibition of infection.

  12. Denture Stomatitis and Candida Albicans in Iranian Population: A Systematic Review and Meta-Analysis

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    Mahmood Moosazadeh

    2016-09-01

    Full Text Available Statement of the Problem: Denture stomatitis is the common form of oral candidiasis, which is seen in the form of diffused inflammation in the areas covered by dentures. Many primary studies report the prevalence of denture stomatitis and candida albicans among patients in the Iranian population; therefore, using meta-analysis is valuable for health policy makers. Purpose: The purpose of the present study is to determine the prevalence of denture stomatitis and candida albicans in Iran. Materials and Method: Using relevant keywords, national and international databases were searched. After limiting the search strategy and deleting the duplicates, the remaining papers were screened by examining the title and abstract. In order to increase the sensitivity of search reference lists of papers were examined. Finally the index of heterogeneity between studies was defined using Cochran test (Q and I-squared (I2. According to heterogeneity, the random effects model was used to estimate the prevalence of denture stomatitis and candida albicans in Iran. Result: The prevalence of denture stomatitis in 12 studies, and the prevalence of candida albicans in patients with denture stomatitis have been reported in 6 studies. The number of sample under investigated and its age range among primary studies included meta- analysis was 2271 individuals and 32.7 till 87.5 years respectively. The prevalence of denture stomatitis in preliminary studies imported to a meta-analysis varied from 1.9% to 54.6%, and its rate in Iran using the meta-analysis was estimated 28.9 % (CI 95%: 18.2-39.6. Also the overall prevalence of candida albicans in patients with denture stomatitis in Iran was estimated 60.6% (CI 95%:50.1-71.2. Conclusion: This study showed that the prevalence of denture stomatitis and candida albicans among patient infected denture stomatitis is relatively significant in Iran.

  13. Sensitization of Candida albicans biofilms to fluconazole by terpenoids of plant origin.

    Science.gov (United States)

    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

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

    Institute of Scientific and Technical Information of China (English)

    Ghaleb Adwan; Yousef Salameh; Kamel Adwan; Ali Barakat

    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.

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

    Science.gov (United States)

    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

  16. Hsp90 governs echinocandin resistance in the pathogenic yeast Candida albicans via calcineurin.

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    Sheena D Singh

    2009-07-01

    Full Text Available Candida albicans is the leading fungal pathogen of humans, causing life-threatening disease in immunocompromised individuals. Treatment of candidiasis is hampered by the limited number of antifungal drugs whose efficacy is compromised by host toxicity, fungistatic activity, and the emergence of drug resistance. We previously established that the molecular chaperone Hsp90, which regulates the form and function of diverse client proteins, potentiates resistance to the azoles in C. albicans and in the model yeast Saccharomyces cerevisiae. Genetic studies in S. cerevisiae revealed that Hsp90's role in azole resistance is to enable crucial cellular responses to the membrane stress exerted by azoles via the client protein calcineurin. Here, we demonstrate that Hsp90 governs cellular circuitry required for resistance to the only new class of antifungals to reach the clinic in decades, the echinocandins, which inhibit biosynthesis of a critical component of the fungal cell wall. Pharmacological or genetic impairment of Hsp90 function reduced tolerance of C. albicans laboratory strains and resistance of clinical isolates to the echinocandins and created a fungicidal combination. Compromising calcineurin function phenocopied compromising Hsp90 function. We established that calcineurin is an Hsp90 client protein in C. albicans: reciprocal co-immunoprecipitation validated physical interaction; Hsp90 inhibition blocked calcineurin activation; and calcineurin levels were depleted upon genetic reduction of Hsp90. The downstream effector of calcineurin, Crz1, played a partial role in mediating calcineurin-dependent stress responses activated by echinocandins. Hsp90's role in echinocandin resistance has therapeutic potential given that genetic compromise of C. albicans HSP90 expression enhanced the efficacy of an echinocandin in a murine model of disseminated candidiasis. Our results identify the first Hsp90 client protein in C. albicans, establish an entirely

  17. Divergent responses of different endothelial cell types to infection with Candida albicans and Staphylococcus aureus.

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    Kati Seidl

    Full Text Available Endothelial cells are important in the pathogenesis of bloodstream infections caused by Candida albicans and Staphylococcus aureus. Numerous investigations have used human umbilical vein endothelial cells (HUVECs to study microbial-endothelial cell interactions in vitro. However, the use of HUVECs requires a constant supply of umbilical cords, and there are significant donor-to-donor variations in these endothelial cells. The use of an immortalized endothelial cell line would obviate such difficulties. One candidate in this regard is HMEC-1, an immortalized human dermal microvascular endothelial cell line. To determine if HMEC-1 cells are suitable for studying the interactions of C. albicans and S. aureus with endothelial cells in vitro, we compared the interactions of these organisms with HMEC-1 cells and HUVECs. We found that wild-type C. albicans had significantly reduced adherence to and invasion of HMEC-1 cells as compared to HUVECs. Although wild-type S. aureus adhered to and invaded HMEC-1 cells similarly to HUVECs, an agr mutant strain had significantly reduced invasion of HMEC-1 cells, but not HUVECs. Furthermore, HMEC-1 cells were less susceptible to damage induced by C. albicans, but more susceptible to damage caused by S. aureus. In addition, HMEC-1 cells secreted very little IL-8 in response to infection with either organism, whereas infection of HUVECs induced substantial IL-8 secretion. This weak IL-8 response was likely due to the anatomic site from which HMEC-1 cells were obtained because infection of primary human dermal microvascular endothelial cells with C. albicans and S. aureus also induced little increase in IL-8 production above basal levels. Thus, C. albicans and S. aureus interact with HMEC-1 cells in a substantially different manner than with HUVECs, and data obtained with one type of endothelial cell cannot necessarily be extrapolated to other types.

  18. Intestinal colonization by Candida albicans alters inflammatory responses in Bruton's tyrosine kinase-deficient mice.

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    Karin Strijbis

    Full Text Available The commensal yeast Candida albicans is part of the human intestinal microflora and is considered a "pathobiont", a resident microbe with pathogenic potential yet harmless under normal conditions. The aim of this study was to investigate the effect of C. albicans on inflammation of the intestinal tract and the role of Bruton's tyrosine kinase (Btk. Btk is an enzyme that modulates downstream signaling of multiple receptors involved in innate and adaptive immunity, including the major anti-fungal receptor Dectin-1. Colitis was induced in wild type and Btk-/- mice by treatment with dextran sodium sulfate (DSS and the gastrointestinal tract of selected treatment groups were then colonized with C. albicans. Colonization by C. albicans neither dampened nor exacerbated inflammation in wild type mice, but colon length and spleen weight were improved in Btk-deficient mice colonized with C. albicans. Neutrophil infiltration was comparable between wild type and Btk-/- mice, but the knockout mice displayed severely reduced numbers of macrophages in the colon during both DSS and DSS/Candida treatment. Smaller numbers and reduced responsiveness of Btk-/- macrophages might partially explain the improved colon length of Btk-/- mice as a result of Candida colonization. Surprisingly, DSS/Candida-treated Btk-/- animals had higher levels of certain pro-inflammatory cytokines and levels of the anti-inflammatory cytokine TGF-β were reduced compared to wild type. A clustering and correlation analysis showed that for wild type animals, spleen TGF-β and colon IL-10 and for Btk-/- spleen and colon levels of IL-17A best correlated with the inflammatory parameters. We conclude that in Btk-/- immunocompromised animals, colonization of the gastrointestinal tract by the commensal yeast C. albicans alters inflammatory symptoms associated with colitis.

  19. Multilocus Sequence Typing of Candida Albicans%白念珠菌多位点序列分型研究

    Institute of Scientific and Technical Information of China (English)

    郭雅莉; 李春莉; 刘原君; 王惠平

    2012-01-01

    Objective To characterize different Candida alb icons isolated through mullilocus sequence typing(MLST), a molecular epidemiologic method was established. Methods Extract the DNA of 33 C.albicans isolated. Seven house-keeping genes were selected as target genes,and PCR was applied. Sequencing,analysis and comparison of the genes were conducted. The MLST results were compared with results obtained by ABC (ATP-binding cassette)-typing. Results Thirty-three isolated C.albwans were typed and 33 STs(sequence types)were found by MLST. ABC-typing produce three types. Conclusion The MLST assay had higher discrimination power.As a convenient and fast molecular typing method,MLST could be used to study the diversity of C.albicans and be applied to epidemiological research.%目的 研究白念珠菌的分子特征,建立分子流行病学研究方法—多位点序列分型技术(MLST),并对临床分离白念珠菌进行分型研究.方法 对33株白念珠菌提取DNA,选择7对管家基因进行PCR扩增并将目的基因产物测序,然后将测序结果与标准序列比对后上传至数据库,获得相应的由7对管家基因组成的等位基因谱,最后将等位基因谱再次提交网站确认序列分型(sequence types,STs).同时与ABC (ATP-binding cassette)分型结果进行比较.结果 33株临床白念珠菌通过MLST产生了33个STs,通过ABC分类为3型.结论 MLST具有较高的分辨力,是一种方便、快速的分子生物学方法,可用于流行病学和菌群多态性的研究.

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

    Science.gov (United States)

    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.

  1. In vitro effects of Salvia officinalis L. essential oil on Candida albicans

    Institute of Scientific and Technical Information of China (English)

    Tularat Sookto; Theerathavaj Srithavaj; Sroisiri Thaweboon; Boonyanit Thaweboon; Binit Shrestha

    2013-01-01

    Objective: To determine the anticandidal activities of Salvia officinalis L. (S. officinalis) essential oil against Candida albicans (C. albicans) and the inhibitory effects on the adhesion of C. albicans to polymethyl methacrylate (PMMA) resin surface. Methods: Disc diffusion method was first used to test the anticandidal activities of the S. officinalis L. essential oil against the reference strain (ATCC 90028) and 2 clinical strains of C. albicans. Then the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were determined by modified membrane method. The adhesion of C. albicans to PMMA resin surface was assessed after immersion with S. officinalis L. essential oil at various concentrations of 1×MIC, 0.5×MIC and 0.25×MIC at room temperature for 30 min. One-way ANOVA was used to compare the Candida cell adhesion with the pretreatment agents and Tukey’s test was used for multiple comparisons. Results: S. officinalis L. essential oil exhibited anticandidal activity against all strains of C. albicans with inhibition zone ranging from 40.5 mm to 19.5 mm. The MIC and MLC of the oil were determined as 2.780 g/L against all test strains. According to the effects on C. albicans adhesion to PMMA resin surface, it was found that immersion in the essential oil at concentrations of 1×MIC (2.780 g/L), 0.5×MIC (1.390 g/L) and 0.25×MIC (0.695 g/L) for 30 min significantly reduced the adhesion of all 3 test strains to PMMA resin surface in a dose dependent manner (P<0.05). Conclusions: S. officinalis L. essential oil exhibited anticandidal activities against C. albicans and had inhibitory effects on the adhesion of the cells to PMMA resin surface. With further testing and development, S. officinalis essential oil may be used as an antifungal denture cleanser to prevent candidal adhesion and thus reduce the risk of candida-associated denture stomatitis.

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

    Science.gov (United States)

    Liu, Ning-Ning; Köhler, Julia R

    2016-02-01

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

  3. Effect of Inula viscosa extract on chitin synthesis in dermatophytes and Candida albicans.

    Science.gov (United States)

    Maoz, M; Neeman, I

    2000-08-01

    An antimycotic effect of an extract from Inula viscosa leaves was demonstrated affecting chitin synthesis in dermatophytes and Candida albicans. The antimycotic effect was compared to the effect caused by miconazole nitrate--an antifungal drug. The inhibition effect on chitin synthesis was not correlated to the extent of growth inhibition caused by the antifungal agents: both miconazole nitrate and the I. viscosa extract inhibited the growth of dermatophytes and C. albicans. Miconazole nitrate did not affect chitin synthesis--except for M. canis--whereas I. viscosa extract caused a significant decline in chitin content.

  4. In vitro activity of zinc oxide-eugenol and glass ionomer cements on Candida albicans

    OpenAIRE

    2005-01-01

    The aim of this study was to evaluate in vitro the antimicrobial activity of glass ionomer (GIC) and zinc oxide-eugenol (ZOE) cements against Candida albicans. Standardized GIC and ZOE specimens were maintained in contact with C. albicans suspension (1 ´ 10(6) cells/ml) at 37°C for 24 h, 48 h or 7 days. A control group without any testing cement was included. After the incubation period, aliquots of 0.1 ml were plated on Sabouraud's agar, and then the number of colonies was counted....

  5. 侵袭性白色假丝酵母菌院内传播的分子机制研究%Molecular mechanism of nosocomial transmission of invasive Candida albicans

    Institute of Scientific and Technical Information of China (English)

    栗方; 王春雷; 曹彬; 巫琳; 李晓莉; 刘颖梅; 曲久鑫; 黎斌斌; 王珊珊; 杨春霞; 刘振嘉

    2012-01-01

    OBJECTIVE To investigate epidemiological characteristics, diversity and genotyping distribution of invasive Candida albicans from 2000 to 2010 in Beijing Chaoyang Hospital, to investigate molecular mechanisms of nosocomial transmission of invasive C. albicans. METHODS A total of 82 strains of invasive C. albicans were collected, the identification of the strains was performed by Chromagar agar with vitek 2 compact YST card; the microsatellite sequences in stable genes CAI were amplified and genotyped by single-strand conformation polymorphisms (SSCP) of C. albicans' microsatellite CAI combined with the GeneScan data for invasive C. albicans genotype comparative analysis. The determination of MIC of 5 drugs (5-fluorocytosine, amphotericin B, fluconazole, itraconazole, voriconazole) was performed by ATB FUNGUS 3 system. RESULTS From Jan 2000 to Dec 2010, of 2320 strains of pathogens causing bloodstream infections, there were 148 (6. 4%) strains of invasive Candida, among which C. albicans accounted for 41. 22% (61 strains), ranking the first place; a total of 4093 strains of pathogens were isolated from sterile fluids,among which invasive Candida were 253 strains (6. 2%) , C. albicans accounted for 59. 29% (150 strains); of 82 independent strains, 38 distinct CAI genotypes were identified by GeneScan analysis; the genotypes of C, albicans isolated from various specimens from 6 patients showed exactly the same; the invasive C. albicans infection was the most common in ICU, which was worthy of attentions the drug susceptibility testing results showed that the drug susceptibility rates of invasive Candida albicans to 5-fluorocytosine, amphotericin B, voriconazole, and posaconazole were all 100. 00%, fluconazole 97. 56%. CONCLUSION C. albicans infection remains the first place among invasive Candida infections, the genotyping indicates that invasive C. albicans is polymorphic, and the genotype of the invasive C, albicans are associated with that oi the coionized isolates

  6. Molecular typing of Candida albicans strains isolated from nosocomial candidemia Tipificação molecular de espécies de Candida albicans isoladas de candidemia hospitalar

    Directory of Open Access Journals (Sweden)

    Maria Luiza Moretti Branchini

    1995-12-01

    Full Text Available Yeasts of the genus Candida have been recognized as important microorganisms responsible for nosocomial fungemia. Six blood-stream and two intravenous central catheter C. albicans strains were isolated from eight patients and studied by electrophoretic karyotyping of chromosomal DNA by pulsed-field gel electrophoresis. Seven chromosomal DNA profiles were identified. Two patients showed isolates with the same profile, suggesting nosocomial transmission. Karyotyping of C. albicans revealed an excellent discriminatory power among the isolates and may therefore be useful in the study of nosocomial candidemia.Leveduras do gênero Candida têm sido reconhecidas como importantes causadoras de fungemias hospitalares. Foram estudados os DNA cromossômicos de oito cepas de C. albicans, obtidas de oito pacientes com fungemia hospitalar, por cariotipagem eletroforética através de "pulsed-field gel electrophoresis". As cepas foram obtidas pelo isolamento da levedura em seis hemoculturas e duas infecções relacionadas ao uso de cateter intra-venoso central. Foram identificados sete perfis de DNA cromossômico. Dois pacientes mostraram cepas com o mesmo perfil de DNA sugerindo transmissão nosocomial. A cariotipagem eletroforética revelou excelente capacidade discriminatória entre os isolados sendo útil no estudo das candidemias hospitalares.

  7. Expression of secretory aspartyl proteinase2 gene of Candida albicans in Escherichia coli and purification of its product%白念珠菌天冬氨酸蛋白酶基因SAP2在大肠杆菌中的表达及产物纯化

    Institute of Scientific and Technical Information of China (English)

    李蕾; 仇萌; 邹先彪

    2013-01-01

    Objective To construct the SAP 2 prokaryotic expression vector, to express and purify solvable protein, so as to lay a foundation for antibody preparation and Sap2 antigen detection. Methods After the target gene fragment SAP 2 was obtained by standard PCR amplification, the SAP 2 and plasmids pMAL-c2x ( + ) were cleaved with two restriction endonucleases, and the digestion products were connected. Ligation products were transformed into competent cell, E. coli TOP10. Then positive clones of re-combined plasmid were screened and identified by DNA sequencing. After recombinant plasmid pMAL-c2x/SAP2 was transformed into E. coli strain BL21 ( DE3) which was induced by IPTG subsequently. The fusion protein was purified by Amylose Resin affinity chromatography, and then was cleaved by Xa factor. Results The target gene SAP 2 amplified by PCR had the same molecular size as predicted. It was inserted directionally into vector pMAL-c2x ( + ). Procaryotic expression plasmid pMAL-c2x/SAP2 can express soluble fusion protein MBP-Sap2 by IPTG induction 14 h later. Total 32 mg target protein Sap2 was obtained after purifying and cleaving label. Conclusion The recombined plasmid pMAL-c2x/SAP2 is successfully and highly expressed in BL21 (DE3) with soluble form. Target protein Sap2 was successfully obtained through affinity chromatography and proteinase cleavage.%目的 构建SAP2重组原核表达载体并表达、纯化出可溶性的蛋白,为抗体制备及Sap2抗原检测奠定基础.方法 提取白念珠菌基因组DNA为模板,经PCR方法获取SAP2目的基因.双酶切SAP2基因与原核表达载体pMAL-c2x(+),连接酶切产物,转化大肠杆菌TOP10感受态细菌,筛选菌落和测序鉴定.将pMAL-c2x/SAP2重组质粒转化大肠杆菌BL21(DE3)感受态细胞,经异丙基硫代-β-D-半乳糖苷(IPTG)诱导表达出可溶性的融合蛋白,经直链淀粉树脂亲和层析、蛋白酶Factor Xa切割标签获得纯化的Sap2蛋白.结果

  8. Functional characterization of Candida albicans Hos2 histone deacetylase [v3; ref status: indexed, http://f1000r.es/3xh

    Directory of Open Access Journals (Sweden)

    G Karthikeyan

    2014-07-01

    Full Text Available 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 (HighOsmolarity 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.

  9. The NDR/LATS kinase Cbk1 controls the activity of the transcriptional regulator Bcr1 during biofilm formation in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Pilar Gutiérrez-Escribano

    Full Text Available In nature, many microorganisms form specialized complex, multicellular, surface-attached communities called biofilms. These communities play critical roles in microbial pathogenesis. The fungal pathogen Candida albicans is associated with catheter-based infections due to its ability to establish biofilms. The transcription factor Bcr1 is a master regulator of C. albicans biofilm development, although the full extent of its regulation remains unknown. Here, we report that Bcr1 is a phosphoprotein that physically interacts with the NDR kinase Cbk1 and undergoes Cbk1-dependent phosphorylation. Mutating the two putative Cbk1 phosphoacceptor residues in Bcr1 to alanine markedly impaired Bcr1 function during biofilm formation and virulence in a mouse model of disseminated candidiasis. Cells lacking Cbk1, or any of its upstream activators, also had reduced biofilm development. Notably, mutating the two putative Cbk1 phosphoacceptor residues in Bcr1 to glutamate in cbk1Δ cells upregulated the transcription of Bcr1-dependent genes and partially rescued the biofilm defects of a cbk1Δ strain. Therefore, our data uncovered a novel role of the NDR/LATS kinase Cbk1 in the regulation of biofilm development through the control of Bcr1.

  10. Bisbibenzyls, a new type of antifungal agent, inhibit morphogenesis switch and biofilm formation through upregulation of DPP3 in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Li Zhang

    Full Text Available The yeast-to-hypha transition plays a crucial role in the pathogenesis of C. albicans. Farnesol, a quorum sensing molecule (QSM secreted by the fungal itself, could prevent the formation of hyphae and subsequently lead to the defect of biofilm formation. The DPP3, encoding phosphatase, is a key gene in regulating farnesol synthesis. In this study, we screened 24 bisbibenzyls and 2 bibenzyls that were isolated from bryophytes or chemically synthesized by using CLSI method for antifungal effect. Seven bisbibenzyls were found to have antifungal effects with IC(80 less than 32 µg/ml, and among them, plagiochin F, isoriccardin C and BS-34 were found to inhibit the hyphae and biofilm formation of C. albicans in a dose-dependent manner. To uncover the underlying relationship between morphogenesis switch and QSM formation, we measured the farnesol production by HPLC-MS and quantified Dpp3 expression by detecting the fluorescent intensity of green fluorescent protein tagged strain using Confocal Laser Scanning microscopy and Multifunction Microplate Reader. The DPP3 transcripts were determined by real-time PCR. The data indicated that the bisbibenzyls exerted antifungal effects through stimulating the synthesis of farnesol via upregulation of Dpp3, suggesting a potential antifungal application of bisbibenzyls. In addition, our assay provides a novel, visual and convenient method to measure active compounds against morphogenesis switch.

  11. Tratamiento opcional de la diarrea producida por Cándida albicans en el cerdito (Optional treatment of scout caused for Candida albicans in piglets

    Directory of Open Access Journals (Sweden)

    Montejo Cuenca, Emilio

    2007-11-01

    Full Text Available Resumen Con el objetivo de comparar la eficacia de los tratamientos con la tintura de la hojas de guayaba (Psidium guajava L., tintura de las flores de manzanilla (Chrysantellum americanum L y el Hefrotrin 120 en las diarreas producidas por Candida albicans en el cerdito. Se trataron 80 crías porcinas entre 7 y 33 días de nacidas, afectadas por diarreas producidas por Candida albicans. Los resultados se analizaron utilizándose una comparación de proporciones mediante un análisis de varianza para %. El agente etiológico se aisló en el 90% de las muestras de heces fecales antes del tratamiento y en 100% de las muestras de pienso enviadas al laboratorio. Las diarreas se caracterizaron por 72,5% de heces líquidas y amarillas. El 45% de los animales estaba deshidratado y el 90% con anorexia. Se demostró que el tratamiento con la tintura de las hojas de guayaba y con la tintura de las flores de manzanilla es efectivo en la terapéutica de los trastornos gastroentéricos originados por la Cándida albicans en el cerdo; se observaron resultados similares a los obtenidos con Hefrotrin 120. Abstract The objective of the survey was to compare the effectiveness of a treatment using guava tincture, manzanilla tincture and Hefrotrine-120. In diarrheas produced by Candida Albicans were treated eighty piglets from 7 to 33 days affected by this diarrhea. The results were analized using a proportion comparation by means a variance analisys as %. The etiologic agent was isolated in the 90% of the feces samples before treatment and in three feed samples send to the lab. The scoun was characterized for 72,5% of liquid and yellow feces. The 45% of the animal were dehydrated and the 90% with anorexia. It was shown that the treatment with guava leaves tincture and chamomile flowers was clearly effective in the therapy in the gastrointestinal disturbances caused for Candida albicans in swine. The results obtained were similar to the ones got by using Hefrotrin

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

    Science.gov (United States)

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

    2002-01-01

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

  13. Dendritic cell interaction with Candida albicans critically depends on N-linked mannan.

    NARCIS (Netherlands)

    Cambi, A.; Netea, M.G.; Mora-Montes, H.M.; Gow, N.A.; Hato, S.V.; Lowman, D.W.; Kullberg, B.J.; Torensma, R.; Williams, D.L.; Figdor, C.G.

    2008-01-01

    The fungus Candida albicans is the most common cause of mycotic infections in immunocompromised hosts. Little is known about the initial interactions between Candida and immune cell receptors, because a detailed characterization at the structural level is lacking. Antigen-presenting dendritic cells

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

    Science.gov (United States)

    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 (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.

  15. Differential adaptation of Candida albicans in vivo modulates immune recognition by dectin-1

    NARCIS (Netherlands)

    Marakalala, M.J.; Vautier, S.; Potrykus, J.; Walker, L.A.; Shepardson, K.M.; Hopke, A.; Mora-Montes, H.M.; Kerrigan, A.; Netea, M.G.; Murray, G.I.; MacCallum, D.M.; Wheeler, R.; Munro, C.A.; Gow, N.A.; Cramer, R.A.; Brown, A.J.; Brown, G.D.

    2013-01-01

    The beta-glucan receptor Dectin-1 is a member of the C-type lectin family and functions as an innate pattern recognition receptor in antifungal immunity. In both mouse and man, Dectin-1 has been found to play an essential role in controlling infections with Candida albicans, a normally commensal fun

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

    Science.gov (United States)

    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.

  17. Control of Candida albicans morphology and pathogenicity by post-transcriptional mechanisms.

    Science.gov (United States)

    Kadosh, David

    2016-11-01

    Candida albicans is a major human fungal pathogen responsible for both systemic and mucosal infections in a wide variety of immunocompromised individuals. Because the ability of C. albicans to undergo a reversible morphological transition from yeast to filaments is important for virulence, significant research efforts have focused on mechanisms that control this transition. While transcriptional and post-translational mechanisms have been well-studied, considerably less is known about the role of post-transcriptional mechanisms. However, in recent years several discoveries have begun to shed light on this important, but understudied, area. Here, I will review a variety of post-transcriptional mechanisms that have recently been shown to control C. albicans morphology, virulence and/or virulence-related processes, including those involving alternative transcript localization, mRNA stability and translation. I will also discuss the role that these mechanisms play in other pathogens as well as the potential they may hold to serve as targets for new antifungal strategies. Ultimately, gaining a better understanding of C. albicans post-transcriptional mechanisms will significantly improve our knowledge of how morphogenesis and virulence are controlled in fungal pathogens and open new avenues for the development of novel and more effective antifungals.

  18. Candida albicans-associated necrotizing vasculitis producing life-threatening gastrointestinal hemorrhage.

    LENUS (Irish Health Repository)

    Sargent, Jeremy

    2012-02-01

    Patients undergoing treatment of acute lymphoblastic leukemia are at risk for fungal infections including disseminated candidiasis. We describe a case of systemic Candida albicans infection associated with life-threatening gastrointestinal hemorrhage due to unusual necrotizing vasculitis involving the gastrointestinal tract. We explore the association between Candida and such vasculopathy.

  19. Systemic neonatal candidosis: the karyotyping of Candida albicans strains isolated from neonates and health-workers.

    Science.gov (United States)

    Ben Abdeljelil, J; Ben Saida, N; Saghrouni, F; Fathallah, A; Boukadida, J; Sboui, H; Ben Said, M

    2010-01-01

    Candida albicans has become an important cause of nosocomial infections in neonatal intensive care units (NICUs). The aim of the present study was to compare C. albicans strains isolated from neonates (NN) suffering from systemic candidosis and from nurses in order to determine the relatedness between NN and health workers' strains. Thirty-one C. albicans strains were isolated from 18 NN admitted to the NICU of the neonatology service of Farhat Hached Hospital of Sousse, Tunisia and suffering from systemic candidosis, together with five strains recovered from nurses suffering from C. albicans onychomycosis. Two additional strains were tested, one from an adult patient who developed a systemic candidosis and the second from an adult with inguinal intertrigo. All strains were karyotyped by pulsed-field gel electrophoresis (PFGE) with a CHEF-DR II system. Analysis of PFGE patterns yielded by the 38 strains tested led to the identification of three pulsotypes that were designated I, II and III, and consisted of six chromosomal bands with a size ranging from 700 to >2500 kbp. The most widespread was the pulsotype I, which was shared by 17 NN and the five nurses' strains. The identity between NN and nurses' strains is very suggestive of a nosocomial acquisition from health-workers.

  20. Inhibition of germ tube's formation of Candida albicans by lactobacillus spp.

    Institute of Scientific and Technical Information of China (English)

    TANG Huan; WEI Hong

    2006-01-01

    Objective:To investigate the effec