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Sample records for albicans predicts arf

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

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    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

  2. A chemometric approach for prediction of antifungal activity of some benzoxazole derivatives against Candida albicans

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    Podunavac-Kuzmanović Sanja O.

    2012-01-01

    Full Text Available The purpose of the article is to promote and facilitate prediction of antifungal activity of the investigated series of benzoxazoles against Candida albicans. The clinical importance of this investigation is to simplify design of new antifungal agents against the fungi which can cause serious illnesses in humans. Quantitative structure activity relationship analysis was applied on nineteen benzoxazole derivatives. A multiple linear regression (MLR procedure was used to model the relationships between the molecular descriptors and the antifungal activity of benzoxazole derivatives. Two mathematical models have been developed as a calibration models for predicting the inhibitory activity of this class of compounds against Candida albicans. The quality of the models was validated by the leave-one-out technique, as well as by the calculation of statistical parameters for the established model. [Projekat Ministarstva nauke Republike Srbije, br. 172012 i br. 172014

  3. Role of Arf GTPases in fungal morphogenesis and virulence

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    Labbaoui, Hayet; Bogliolo, Stéphanie; Ghugtyal, Vikram; Solis, Norma V.

    2017-01-01

    Virulence of the human fungal pathogen Candida albicans depends on the switch from budding to filamentous growth, which requires sustained membrane traffic and polarized growth. In many organisms, small GTPases of the Arf (ADP-ribosylation factor) family regulate membrane/protein trafficking, yet little is known about their role in fungal filamentous growth. To investigate these GTPases in C. albicans, we generated loss of function mutants in all 3 Arf proteins, Arf1-Arf3, and 2 Arf-like proteins, Arl1 and Arl3. Our results indicate that of these proteins, Arf2 is required for viability and sensitivity to antifungal drugs. Repressible ARF2 expression results in defects in filamentous growth, cell wall integrity and virulence, likely due to alteration of the Golgi. Arl1 is also required for invasive filamentous growth and, although arl1/arl1 cells can initiate hyphal growth, hyphae are substantially shorter than that of the wild-type, due to the inability of this mutant to maintain hyphal growth at a single site. We show that this defect does not result from an alteration of phospholipid distribution and is unlikely to result from the sole Golgin Imh1 mislocalization, as Imh1 is not required for invasive filamentous growth. Rather, our results suggest that the arl1/arl1 hyphal growth defect results from increased secretion in this mutant. Strikingly, the arl1/arl1 mutant is drastically reduced in virulence during oropharyngeal candidiasis. Together, our results highlight the importance of Arl1 and Arf2 as key regulators of hyphal growth and virulence in C. albicans and identify a unique function of Arl1 in secretion. PMID:28192532

  4. Concurrent disruption of p16INK4a and the ARF-p53 pathway predicts poor prognosis in aggressive non-Hodgkin's lymphoma

    DEFF Research Database (Denmark)

    Grønbaek, K; de Nully Brown, P; Møller, Michael Boe

    2000-01-01

    %) cases with aggressive histology. For the aggressive lymphomas, the Kaplan-Meier estimate of overall survival for cases with disruption of either p16INK4a or the ARF-p53 pathway was not different from cases with retention of both pathways (5 year survival 45% vs 35%; P= 0.85), suggesting that selective...... inactivation of one of the pathways does not significantly influence overall survival. By contrast, the 5-year survival was only 7% for cases with concurrent disruption of p16INK4a and the ARF-p53 pathway vs 38% for cases with retention of one or both pathways (P = 0.005). Similar results were obtained when...... the analysis was confined to diffuse large B cell lymphomas (P= 0.019). On stepwise multivariate regression analysis including factors from the international prognostic index, concurrent disruption of p16INK4a and the ARF-p53 pathway was an independent negative prognostic factor in NHL with aggressive...

  5. The TRIP from ULF to ARF.

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    Collado, Manuel; Serrano, Manuel

    2010-04-13

    ARF is a key activator of p53, and together they form a critical duo for protection against cancer. Previous evidence had recognized the regulatory potential of ubiquitin-mediated degradation of ARF. The recent identification of TRIP12/ULF as a ubiquitin ligase of ARF adds an important missing piece to the ARF/p53 pathway.

  6. Genomewide identification and expression analysis of the ARF gene family in apple

    Indian Academy of Sciences (India)

    Xiao-Cui Luo; Mei-Hong Sun; Rui-Rui Xu; Huai-Rui Shu; Jai-Wei Wang; Shi-Zhong Zhang

    2014-12-01

    Auxin response factors (ARF) are transcription factors that regulate auxin responses in plants. Although the genomewide analysis of this family has been performed in some species, little is known regarding ARF genes in apple (Malus domestica). In this study, 31 putative apple ARF genes have been identified and located within the apple genome. The phylogenetic analysis revealed that MdARFs could be divided into three subfamilies (groups I, II and III). The predicted MdARFs were distributed across 15 of 17 chromosomes with different densities. In addition, the analysis of exon–intron junctions and of the intron phase inside the predicted coding region of each candidate gene has revealed high levels of conservation within and between phylogenetic groups. Expression profile analyses of MdARF genes were performed in different tissues (root, stem, leaf, flower and fruit), and all the selected genes were expressed in at least one of the tissues that were tested, which indicated that MdARFs are involved in various aspects of physiological and developmental processes of apple. To our knowledge, this report is the first to provide a genomewide analysis of the apple ARF gene family. This study provides valuable information for understanding the classification and putative functions of the ARF signal in apple.

  7. The Drosophila Arf1 homologue Arf79F is essential for lamellipodium formation

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    Humphreys, Daniel; Liu, Tao; Davidson, Anthony C.; Hume, Peter J.; Koronakis, Vassilis

    2012-01-01

    Summary The WAVE regulatory complex (WRC) drives the polymerisation of actin filaments located beneath the plasma membrane to generate lamellipodia that are pivotal to cell architecture and movement. By reconstituting WRC-dependent actin assembly at the membrane, we recently discovered that several classes of Arf family GTPases directly recruit and activate WRC in cell extracts, and that Arf cooperates with Rac1 to trigger actin polymerisation. Here, we demonstrate that the Class 1 Arf1 homologue Arf79F colocalises with the WRC at dynamic lamellipodia. We report that Arf79F is required for lamellipodium formation in Drosophila S2R+ cells, which only express one Arf isoform for each class. Impeding Arf function either by dominant-negative Arf expression or by Arf double-stranded RNA interference (dsRNAi)-mediated knockdown uncovered that Arf-dependent lamellipodium formation was specific to Arf79F, establishing that Class 1 Arfs, but not Class 2 or Class 3 Arfs, are crucial for lamellipodia. Lamellipodium formation in Arf79F-silenced cells was restored by expressing mammalian Arf1, but not by constitutively active Rac1, showing that Arf79F does not act via Rac1. Abolition of lamellipodium formation in Arf79F-silenced cells was not due to Golgi disruption. Blocking Arf79F activation with guanine nucleotide exchange factor inhibitors impaired WRC localisation to the plasma membrane and concomitant generation of lamellipodia. Our data indicate that the Class I Arf GTPase is a central component in WRC-driven lamellipodium formation. PMID:22992458

  8. ARF-Aux/IAA interactions through domain III/IV are not strictly required for auxin-responsive gene expression

    OpenAIRE

    2013-01-01

    Auxin response factors (ARFs), together with auxin/indole acetic acid proteins (Aux/IAAs), are transcription factors that play key roles in regulating auxin-responsive transcription in plants. Current models for auxin signaling predict that auxin response is dependent on ARF-Aux/IAA interactions mediated by the related protein-protein interaction domain (i.e., referred to as the CTD) found in the ARF and Aux/IAA C-terminal regions. When auxin concentrations in a cell are low, ARF activators r...

  9. ARF tumor suppression in the nucleolus.

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    Maggi, Leonard B; Winkeler, Crystal L; Miceli, Alexander P; Apicelli, Anthony J; Brady, Suzanne N; Kuchenreuther, Michael J; Weber, Jason D

    2014-06-01

    Since its discovery close to twenty years ago, the ARF tumor suppressor has played a pivotal role in the field of cancer biology. Elucidating ARF's basal physiological function in the cell has been the focal interest of numerous laboratories throughout the world for many years. Our current understanding of ARF is constantly evolving to include novel frameworks for conceptualizing the regulation of this critical tumor suppressor. As a result of this complexity, there is great need to broaden our understanding of the intricacies governing the biology of the ARF tumor suppressor. The ARF tumor suppressor is a key sensor of signals that instruct a cell to grow and proliferate and is appropriately localized in nucleoli to limit these processes. This article is part of a Special Issue entitled: Role of the Nucleolus in Human Disease.

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

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    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.

  11. Auxin-dependent compositional change in Mediator in ARF7- and ARF19-mediated transcription.

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    Ito, Jun; Fukaki, Hidehiro; Onoda, Makoto; Li, Lin; Li, Chuanyou; Tasaka, Masao; Furutani, Masahiko

    2016-06-07

    Mediator is a multiprotein complex that integrates the signals from transcription factors binding to the promoter and transmits them to achieve gene transcription. The subunits of Mediator complex reside in four modules: the head, middle, tail, and dissociable CDK8 kinase module (CKM). The head, middle, and tail modules form the core Mediator complex, and the association of CKM can modify the function of Mediator in transcription. Here, we show genetic and biochemical evidence that CKM-associated Mediator transmits auxin-dependent transcriptional repression in lateral root (LR) formation. The AUXIN/INDOLE 3-ACETIC ACID 14 (Aux/IAA14) transcriptional repressor inhibits the transcriptional activity of its binding partners AUXIN RESPONSE FACTOR 7 (ARF7) and ARF19 by making a complex with the CKM-associated Mediator. In addition, TOPLESS (TPL), a transcriptional corepressor, forms a bridge between IAA14 and the CKM component MED13 through the physical interaction. ChIP assays show that auxin induces the dissociation of MED13 but not the tail module component MED25 from the ARF7 binding region upstream of its target gene. These findings indicate that auxin-induced degradation of IAA14 changes the module composition of Mediator interacting with ARF7 and ARF19 in the upstream region of their target genes involved in LR formation. We suggest that this regulation leads to a quick switch of signal transmission from ARFs to target gene expression in response to auxin.

  12. Endoftalmite por Candida albicans Candida albicans endophthalmitis

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    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.

  13. Interactions between Rab and Arf GTPases regulate endosomal phosphatidylinositol-4,5-bisphosphate during endocytic recycling.

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    Shi, Anbing; Grant, Barth D

    2013-01-01

    After endocytosis, a selective endocytic recycling process returns many endocytosed molecules back to the plasma membrane. The RAB-10/Rab10 GTPase is known to be a key recycling regulator for specific cargo molecules. New evidence, focused on C. elegans RAB-10 in polarized epithelia, points to a key role of RAB-10 in the regulation of endosomal phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) levels. In turn, PI(4,5)P2 levels strongly influence the recruitment of many peripheral membrane proteins, including those important for vesicle budding through their membrane bending activities. Part of the effect of RAB-10 on endosomal PI(4,5)P2 is through its newly identified effector CNT-1, a predicted GTPase activating protein (GAP) of the small GTPase ARF-6/Arf6. In mammals PI(4,5)P2 generating enzymes are known Arf6 effectors. In C. elegans we found that RAB-10, CNT-1 and ARF-6 are present on the same endosomes, that RAB-10 recruits CNT-1 to endosomes, and that loss of CNT-1 or RAB-10 leads to overaccumulation of endosomal PI(4,5)P2, presumably via hyperactivation of endosomal ARF-6. In turn this leads to over-recruitment of PI(4,5)P2-dependent membrane-bending proteins RME-1/Ehd and SDPN-1/Syndapin/PACSIN. Conversely, in arf-6 mutants, endosomal PI(4,5)P2 levels were reduced and endosomal recruitment of RME-1 and SDPN-1 failed. This work makes an unexpected link between distinct classes of small GTPases that control endocytic recycling, and provides insight into how this interaction affects endosome function at the level of lipid phosphorylation.

  14. Decomposition of Plant Debris by the Nematophagous Fungus ARF

    OpenAIRE

    Wang, Kening; Riggs, R. D.; Crippen, Devany

    2004-01-01

    In the study of the biological control of plant-parasitic nematodes, knowledge of the saprophytic ability of a nematophagous fungus is necessary to understand its establishment and survival in the soil. The objectives of this study were (i) to determine if the nematophagous fungus ARF (Arkansas Fungus) shows differential use of plant residues; and (ii) to determine if ARF still existed in the soil of a field in which ARF was found originally and in which the population level of Heterodera gly...

  15. PH Domain-Arf G Protein Interactions Localize the Arf-GEF Steppke for Cleavage Furrow Regulation in Drosophila.

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    Donghoon M Lee

    Full Text Available The recruitment of GDP/GTP exchange factors (GEFs to specific subcellular sites dictates where they activate small G proteins for the regulation of various cellular processes. Cytohesins are a conserved family of plasma membrane GEFs for Arf small G proteins that regulate endocytosis. Analyses of mammalian cytohesins have identified a number of recruitment mechanisms for these multi-domain proteins, but the conservation and developmental roles for these mechanisms are unclear. Here, we report how the pleckstrin homology (PH domain of the Drosophila cytohesin Steppke affects its localization and activity at cleavage furrows of the early embryo. We found that the PH domain is necessary for Steppke furrow localization, and for it to regulate furrow structure. However, the PH domain was not sufficient for the localization. Next, we examined the role of conserved PH domain amino acid residues that are required for mammalian cytohesins to bind PIP3 or GTP-bound Arf G proteins. We confirmed that the Steppke PH domain preferentially binds PIP3 in vitro through a conserved mechanism. However, disruption of residues for PIP3 binding had no apparent effect on GFP-Steppke localization and effects. Rather, residues for binding to GTP-bound Arf G proteins made major contributions to this Steppke localization and activity. By analyzing GFP-tagged Arf and Arf-like small G proteins, we found that Arf1-GFP, Arf6-GFP and Arl4-GFP, but not Arf4-GFP, localized to furrows. However, analyses of embryos depleted of Arf1, Arf6 or Arl4 revealed either earlier defects than occur in embryos depleted of Steppke, or no detectable furrow defects, possibly because of redundancies, and thus it was difficult to assess how individual Arf small G proteins affect Steppke. Nonetheless, our data show that the Steppke PH domain and its conserved residues for binding to GTP-bound Arf G proteins have substantial effects on Steppke localization and activity in early Drosophila embryos.

  16. The small GTPase Arf1 modulates mitochondrial morphology and function.

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    Ackema, Karin B; Hench, Jürgen; Böckler, Stefan; Wang, Shyi Chyi; Sauder, Ursula; Mergentaler, Heidi; Westermann, Benedikt; Bard, Frédéric; Frank, Stephan; Spang, Anne

    2014-11-18

    The small GTPase Arf1 plays critical roles in membrane traffic by initiating the recruitment of coat proteins and by modulating the activity of lipid-modifying enzymes. Here, we report an unexpected but evolutionarily conserved role for Arf1 and the ArfGEF GBF1 at mitochondria. Loss of function of ARF-1 or GBF-1 impaired mitochondrial morphology and activity in Caenorhabditis elegans. Similarly, mitochondrial defects were observed in mammalian and yeast cells. In Saccharomyces cerevisiae, aberrant clusters of the mitofusin Fzo1 accumulated in arf1-11 mutants and were resolved by overexpression of Cdc48, an AAA-ATPase involved in ER and mitochondria-associated degradation processes. Yeast Arf1 co-fractionated with ER and mitochondrial membranes and interacted genetically with the contact site component Gem1. Furthermore, similar mitochondrial abnormalities resulted from knockdown of either GBF-1 or contact site components in worms, suggesting that the role of Arf1 in mitochondrial functioning is linked to ER-mitochondrial contacts. Thus, Arf1 is involved in mitochondrial homeostasis and dynamics, independent of its role in vesicular traffic.

  17. Decomposition of Plant Debris by the Nematophagous Fungus ARF.

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    Wang, Kening; Riggs, R D; Crippen, Devany

    2004-09-01

    In the study of the biological control of plant-parasitic nematodes, knowledge of the saprophytic ability of a nematophagous fungus is necessary to understand its establishment and survival in the soil. The objectives of this study were (i) to determine if the nematophagous fungus ARF (Arkansas Fungus) shows differential use of plant residues; and (ii) to determine if ARF still existed in the soil of a field in which ARF was found originally and in which the population level of Heterodera glycines had remained very low, despite 15 years of continuous, susceptible soybean. Laboratory studies of the decomposition of wheat straw or soybean root by ARF were conducted in two separate experiments, using a CO collection apparatus, where CO-free air was passed through sterilized cotton to remove the microorganisms in the air and then was passed over the samples, and evolved CO was trapped by KOH. Milligrams of C as CO was used to calculate the percentage decomposition of the plant debris by ARF. Data indicated ARF decomposed 11.7% of total organic carbon of the wheat straw and 20.1% of the soybean roots in 6 weeks. In the field soil study, 21 soil samples were taken randomly from the field. Only 3 months after the infestation of the soil with H. glycines, the percentage of parasitized eggs of H. glycines reached 64 +/- 19%, and ARF was isolated from most parasitized eggs of H. glycines. Research results indicated ARF could use plant residues to survive.

  18. Progressive silencing of p14ARF in oesophageal adenocarcinoma.

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    Huang, Yinghui; Peters, Christopher J; Fitzgerald, Rebecca C; Gjerset, Ruth A

    2009-02-01

    The frequency of oesophageal adenocarcinoma is increasing in Western countries for unknown reasons, and correlates with a corresponding increase in the pre-malignant condition, Barrett's Oesophagus, which raises the risk of adenocarcinoma by some 40- to 125-fold. We have examined how disease progression correlates with changes in expression of the p14ARF (ARF) tumour suppressor, a key regulator of the p53 tumour suppressor pathway that is silenced in some 30% of cancers overall, but for which a role in oesophageal cancer is unclear. We have used quantitative PCR, RT-PCR, methylation-specific PCR and chromatin-immunoprecipitation to examine the regulation and function of ARF in oesophageal adenocarcinoma tissue specimens and cell lines. We find highly significant reductions (Poesophageal epithelium to Barrett's Oesophagus to adenocarcinoma, with 57/76 (75%) adenocarcinomas displaying undetectable levels of ARF expression. Retention of ARF expression in adenocarcinoma is a highly significant indicator of increased survival (Padenocarcinoma cell lines and can be reversed by 5-aza-2'-deoxycytidine. The results suggest that silencing of ARF is involved in the pathogenesis of oesophageal adenocarcinoma and show that either DNA or histone methylation can provide the primary mechanism for ARF gene silencing. Silencing of ARF could provide a useful marker for increased risk of progression and poor prognosis.

  19. On type sequences and Arf rings

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    Dilip Premchand Patil

    2007-06-01

    Full Text Available In this article in Section~2 we give an explicit description to compute the type sequence $mathrm{t}_1,ldots,mathrm{t}_{n}$ of a semigroup $Gamma$ generated by an arithmetic sequence (see 2.7; we show that the $i$-th term $mathrm{t}_i$ is equal to $1$ or to the type $au_Gamma$, depending on its position. In Section 3, for analytically irreducible ring $R$ with the branch sequence $R=R_0 subsetneq R_1 subsetneq ldotssubsetneq R_{m-1} subsetneq R_{m} =overline{R}$, starting from a result proved in [4] we give a characterization (see 3.6 of the ``Arf'' property using the type sequence of $R$ and of the rings $R_j$, $1leq jleq m-1$. Further, we prove (see 3.9, 3.10 some relations among the integers $ell^*(R$ and $ell^*(R_j$, $1leq jleq m-1$. These relations and a result of [6] allow us to obtain a new characterization (see 3.12 of semigroup rings of minimal multiplicity with $ell^*(Rleq au(R$ in terms of the Arf property, type sequences and relations between $ell^*(R$ and $ell^*(R_j$, $1leq jleq m-1$.

  20. Concept Framework for Audio Information Retrieval: ARF

    Institute of Scientific and Technical Information of China (English)

    LI GuoHui(李国辉); WU DeFeng(武德峰); ZHANG Jun(张军)

    2003-01-01

    The majority of researches on content-based retrieval focused on visual media.However audio is also an important medium and information carrier from the viewpoint of humanauditory perception, so it is needed to retrieve for audio collection. Audio is handled by conven-tional methods as an opaque stream medium, which is not suitable for information retrieval byits content. In fact, audio carries rich aural information with the form of speech, musical, andsound effects, so it could be retrieved based on its aural content, such as acoustic features, musicalmelodies and associated semantics. In this paper, a concept framework (ARF) for content-basedaudio retrieval is proposed from systematic perspectives, which describes audio content model,audio retrieval architecture and audio query schemes. Audio contents are represented by a hier-archical model and a set of formal descriptions from physical to acoustic to semantic level, whichdepict acoustic features, logical structure and semantics of audio and audio objects. The archi-tecture consisting of audio meta-database, populating and accessing modules presents a systemstructure view of audio information retrieval. The query schemes give generalized approaches andmodes concerning how users deliver audio information needs to audio collections. Finally, an audioretrieval example implemented is used to explain and specify the application of the components in the proposed ARF.

  1. ArfGAP1 function in COPI mediated membrane traffic: currently debated models and comparison to other coat-binding ArfGAPs.

    Science.gov (United States)

    Shiba, Yoko; Randazzo, Paul A

    2012-09-01

    The ArfGAPs are a family of proteins containing an ArfGAP catalytic domain that induces the hydrolysis of GTP bound to the small guanine nucleotide binding-protein ADP-ribosylation factor (Arf). Functional models for Arfs, which are regulators of membrane traffic, are based on the idea that guanine nucleotide-binding proteins function as switches: Arf with GTP bound is active and binds to effector proteins; the conversion of GTP to GDP inactivates Arf. The cellular activities of ArfGAPs have been examined primarily as regulatory proteins that inactivate Arf; however, Arf function in membrane traffic does not strictly adhere to the concept of a simple switch, adding complexity to models explaining the role of ArfGAPs. Here, we review the literature addressing the function Arf and ArfGAP1 in COPI mediated transport, focusing on two critical and integrated functions of membrane traffic, cargo sorting and vesicle coat polymerization. We briefly discuss other ArfGAPs that may have similar function in Arf-dependent membrane traffic outside the ER-Golgi.

  2. Mutual Regulation of FOXM1, NPM and ARF Proteins.

    Science.gov (United States)

    Pandit, Bulbul; Gartel, Andrei L

    2015-01-01

    ARF, NPM and FOXM1 proteins interact with each other in mammalian cells. We showed previously that proteasome inhibitors suppress not only FOXM1 expression, but also the expression of ARF and NPM proteins. Using RNA interference we found that the depletion of each of these proteins by RNAi in human cancer HeLa cells leads to down-regulation of the two other partners, suggesting that these proteins stabilize each other in human cancer cells. Since the suppression of FOXM1 is one of hallmarks of proteasome inhibition, suppression of ARF and NPM by proteasome inhibitors may be explained in part as a secondary effect of downregulation of FOXM1 that modulate stability of ARF and NPM1 proteins.

  3. 番茄ARF2蛋白的生物信息学分析与亚细胞定位%Bioinformatic Analysis and Subcellular Localization of Solanum lycopersicum ARF2

    Institute of Scientific and Technical Information of China (English)

    冯媛媛; 侯佩; 李颖楠; 刘永胜

    2012-01-01

    克隆番茄(Solanum lycopersicum)ARF2基因,并分析其分子特性和亚细胞定位,为研究其功能提供基础.通过生物信息学方法分析SlARF2基因编码蛋白的理化性质和分子特性.采用RT-PCR技术从番茄果实cDNA中扩增SIARF2基因全长,并构建与黄色荧光蛋白(YFP)融合的pBA-ARF2-YFP表达载体,进而再通过农杆菌介导的遗传转化方法,将重组质粒转化到野生型番茄中,将得到的T1代转基因种子萌发,然后取根尖通过荧光显微镜观察了融合蛋白在活细胞内分布的特点.生物信息学分析结果表明,S1ARF2是富含Ser、Leu、Gly和Pro以及具有ARF家族典型结构域的可溶性蛋白,其氨基酸序列与葡萄、木薯和拟南芥的同源性分别为70.08%、66.94%和60.87%.经酶切和测序分析证实pBA-ARF2-YFP融合表达载体构建成功,此外,PCR分析表明融合蛋白在转基因植株中得到表达.经荧光显微镜观察,ARF2定位在细胞核中.表明转录因子S1ARF2定位在细胞核中,对番茄果实发育和成熟起重要作用.%Auxin response factors (ARFs) are important transcription factors involved in auxin signal transduction pathway. In order to elucidate the function of tomato ARF2, we isolated the SIARF2 gene and analyzed its molecular features, in addition, we observed the subcellular localization of ARF2 in transgenic tomato plants. Physicochemical properties and molecular features of ARF2 were predicted by bioinformatic approaches including physical and chemical properties analysis, hydrophobicity analysis, domain analysis, phylogenetic tree analysis and subcellular localization analysis. Moreover, the full-length of SLARF2 gene was amplified by RT-PCR, and a binary vector consisting of ARF2 fused with the yellow fluorescent protein (YFP) coding sequence was further constructed. Using the method of Agrobacterium-mediated transformation, the recombinant vector was transformed into wild-type tomato, and the transgenic tomato

  4. The Arabidopsis ADP-ribosylation factor (ARF) and ARF-like (ARL) system and its regulation by BIG2, a large ARF-GEF

    DEFF Research Database (Denmark)

    Nielsen, Michael; Albrethsen, Jacob; Larsen, Flemming Hofmann

    2006-01-01

    2 fraction was detected in membranes, especially those deriving from the Golgi apparatus. The activity of the BIG2 Sec7 domain was unaffected by the Sec7 inhibitor brefeldin A, suggesting that BIG2 is a BFA-insensitive GEF for ARF1 or a close homolog. These studies contribute to our understanding...

  5. The Role of ARF6 in Biliary Atresia.

    Directory of Open Access Journals (Sweden)

    Mylarappa Ningappa

    Full Text Available Altered extrahepatic bile ducts, gut, and cardiovascular anomalies constitute the variable phenotype of biliary atresia (BA.To identify potential susceptibility loci, Caucasian children, normal (controls and with BA (cases at two US centers were compared at >550000 SNP loci. Systems biology analysis was carried out on the data. In order to validate a key gene identified in the analysis, biliary morphogenesis was evaluated in 2-5-day post-fertilization zebrafish embryos after morpholino-antisense oligonucleotide knockdown of the candidate gene ADP ribosylation factor-6 (ARF6, Mo-arf6.Among 39 and 24 cases at centers 1 and 2, respectively, and 1907 controls, which clustered together on principal component analysis, the SNPs rs3126184 and rs10140366 in a 3' flanking enhancer region for ARF6 demonstrated higher minor allele frequencies (MAF in each cohort, and 63 combined cases, compared with controls (0.286 vs. 0.131, P = 5.94x10-7, OR 2.66; 0.286 vs. 0.13, P = 5.57x10-7, OR 2.66. Significance was enhanced in 77 total cases, which included 14 additional BA genotyped at rs3126184 only (p = 1.58x10-2, OR = 2.66. Pathway analysis of the 1000 top-ranked SNPs in CHP cases revealed enrichment of genes for EGF regulators (p<1 x10-7, ERK/MAPK and CREB canonical pathways (p<1 x10-34, and functional networks for cellular development and proliferation (p<1 x10-45, further supporting the role of EGFR-ARF6 signaling in BA. In zebrafish embryos, Mo-arf6 injection resulted in a sparse intrahepatic biliary network, several biliary epithelial cell defects, and poor bile excretion to the gall bladder compared with uninjected embryos. Biliary defects were reproduced with the EGFR-blocker AG1478 alone or with Mo-arf6 at lower doses of each agent and rescued with arf6 mRNA.The BA-associated SNPs identify a chromosome 14q21.3 susceptibility locus encompassing the ARF6 gene. arf6 knockdown in zebrafish implicates early biliary dysgenesis as a basis for BA, and also

  6. 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.

  7. Novel frameshift mutation in the p16/INK4A tumor suppressor gene in canine breast cancer alters expression from the p16/INK4A/p14ARF locus.

    Science.gov (United States)

    Lutful Kabir, Farruk M; Agarwal, Payal; Deinnocentes, Patricia; Zaman, Jishan; Bird, Allison Church; Bird, R Curtis

    2013-01-01

    The INK4 family of cyclin-dependent kinase inhibitors (CKI) encode important cell cycle regulators that tightly control cell cycle during G1 to S phase. These related genes are considered tumor suppressors as loss of function contributes to the malignant phenotype. Expression of CKIs p16, p14ARF, or p15 were defective in six different canine mammary tumor (CMT) cell lines compared to normal thoracic canine fibroblasts. This suggests CKI defects are frequently responsible for neoplastic transformation in canine mammary carcinomas. p16 and p14ARF are two alternatively spliced products derived from the canine p16/INK4A/p14ARF gene locus. Despite omissions in the published p16 transcript and canine genome and the presence of GC-rich repeats, we determined the complete coding sequence of canine p16 revealing a deletion and frameshift mutation in p16 exon 1α in CMT28 cells. In addition, we determined canine p14ARF mRNA and protein sequences. Mapping of these mutations uncovered important aspects of p16 and p14ARF expression and defects in CMT28 cells shifting the p16 reading frame into p14ARF making a fusion protein that was predicted to be truncated, unstable and devoid of structural and functional integrity. This data describes an important neoplastic mechanism in the p16/INK4A/p14ARF locus in a spontaneous canine model of breast cancer.

  8. Variation in Efficacy of Isolates of the Fungus ARF Against the Soybean Cyst Nematode Heterodera glycines

    OpenAIRE

    Timper, P.; Riggs, R. D.

    1998-01-01

    An unnamed fungus, designated ARF, that parasitizes eggs and sedentary stages of cyst nematodes is a potential biological control agent of Heterodera glycines. The objectives of this study were to determine whether ARF isolates differ in their ability to suppress nematode numbers in soil and to compare the efficacy of ARF in heat-treated and native soil. The effectiveness of 11 ARF isolates was compared by introducing homogenized mycelium into heat-treated soil. Soybean seedlings were transpl...

  9. Juan de Arfe Villafañe y Sebastiano Serlio

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    Heredia Moreno, Mª del Carmen

    2003-12-01

    Full Text Available Juan de Arfe's awareness and utilization of Italian art treatises, particularly that of Sebastiano Serlio, are analyzed in this study. The author demonstrates that Serlio's influence is perceptible in much of this artisan's production, from the Avila monstrance to that of Valladolid. It is especially manifest in Arfe's creations carried out in Seville, particularly in Books I and IV of his Varia Commensuracion and in the monstrance for the cathedral.

    En este artículo se analiza el conocimiento y la utilización de los tratadistas italianos, particularmente de Sebastiano Serlio, por parte de Juan de Arfe. También se tratará de demostrar que la influencia de Serlio se percibe en buena parte de la producción del artífice, desde la custodia de Ávila hasta la de Valladolid, aunque se manifiesta de manera especial en los trabajos que Arfe realizó en Sevilla, sobre todo en los Libros I y IV de la Varia Commensuracion y en la custodia de la catedral.

  10. The human ARF tumor suppressor senses blastema activity and suppresses epimorphic tissue regeneration.

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    Hesse, Robert G; Kouklis, Gayle K; Ahituv, Nadav; Pomerantz, Jason H

    2015-11-17

    The control of proliferation and differentiation by tumor suppressor genes suggests that evolution of divergent tumor suppressor repertoires could influence species' regenerative capacity. To directly test that premise, we humanized the zebrafish p53 pathway by introducing regulatory and coding sequences of the human tumor suppressor ARF into the zebrafish genome. ARF was dormant during development, in uninjured adult fins, and during wound healing, but was highly expressed in the blastema during epimorphic fin regeneration after amputation. Regenerative, but not developmental signals resulted in binding of zebrafish E2f to the human ARF promoter and activated conserved ARF-dependent Tp53 functions. The context-dependent activation of ARF did not affect growth and development but inhibited regeneration, an unexpected distinct tumor suppressor response to regenerative versus developmental environments. The antagonistic pleiotropic characteristics of ARF as both tumor and regeneration suppressor imply that inducing epimorphic regeneration clinically would require modulation of ARF -p53 axis activation.

  11. 小麦生长素响应因子 TaARF6转基因烟草植株分子鉴定%Regulation effects of an auxin response gene in wheat (TaARF6) in mediating plant growth under conditions of normal growth and Pi deprivation

    Institute of Scientific and Technical Information of China (English)

    智一鸣; 陈芳; 刘晓曼; 肖凯

    2016-01-01

    系数量增多、主侧根长度、根体积、叶面积和根冠比增加。【结论】TaARF6编码典型的生长素响应因子,其编码蛋白具有生长素响应因子特有结构域。 TaARF6对环境中的低磷胁迫逆境能产生明显应答。上调表达 TaARF6基因,具有增加植株根、叶鲜、干重和改善根叶及植株形态的生物学功能。本研究表明,通过对植株体内生长素响应基因的转录调控,TaARF6在介导植株不同供磷水平下的根叶形态建成和干物质累积过程中发挥着重要作用。%[Objectives] Auxin response factors (ARFs) play a critical role in mediating transduction of auxin signaling and regulating expression of downstream auxin-responsive genes. In this study, an ARF type transcription factor gene referred to TaARF6 identified in a root suppression subtractive cDNA library that enriches the differentially expressed genes under Pi sufficiency as the basis was used to investigate molecular characterization of TaARF6 and its expression patterns under various Pi-supply conditions, as well as its functions in regulating plant phenotypes. The objective of this study was aimed to elucidate biological roles of TaARF6 in mediating plant growth features under the conditions of Pi sufficiency and Pi deficiency. [ Methods] The protein characterization of TaARF6 was predicted by the bioinformatics’ tools. The seedlings of wheat (cv. Shixin 828) were cultured under the sufficient-and deficient-Pi conditions by a hydroponic approach and used to investigate the expression patterns of TaARF6 based on semi-quantitative RT-PCR. A DNA recombinant technique was adopted to construct the expression cassette integrating the TaARF6 open reading frame. The transgenic tobacco plants overexpressing TaARF6 were generated based on a genetic transformation approach mediated by Agobacterium-tumefaciens using the leaf discs as explants. Based on the culture methods of agar medium and hydroponic solution, the

  12. SlARF2a plays a negative role in mediating axillary shoot formation

    Science.gov (United States)

    Xu, Tao; Liu, Xin; Wang, Rong; Dong, Xiufen; Guan, Xiaoxi; Wang, Yanling; Jiang, Yun; Shi, Zihang; Qi, Mingfang; Li, Tianlai

    2016-01-01

    SlARF2a is expressed in most plant organs, including roots, leaves, flowers and fruits. A detailed expression study revealed that SlARF2a is mainly expressed in the leaf nodes and cross-sections of the nodes indicated that SlARF2a expression is restricted to vascular organs. Decapitation or the application of 6-benzylaminopurine (BAP) can initially promote axillary shoots, during which SlARF2a expression is significantly reduced. Down-regulation of SlARF2a expression results in an increased frequency of dicotyledons and significantly increased lateral organ development. Stem anatomy studies have revealed significantly altered cambia and phloem in tomato plants expressing down-regulated levels of ARF2a, which is associated with obvious alterations in auxin distribution. Further analysis has revealed that altered auxin transport may occur via altered pin expression. To identify the interactions of AUX/IAA and TPL with ARF2a, four axillary shoot development repressors that are down-regulated during axillary shoot development, IAA3, IAA9, SlTPL1 and SlTPL6, were tested for their direct interactions with ARF2a. Although none of these repressors are directly involved in ARF2a activity, similar expression patterns of IAA3, IAA9 and ARF2a implied they might work tightly in axillary shoot formation and other developmental processes. PMID:27645097

  13. IGF-1 drives chromogranin A secretion via activation of Arf1 in human neuroendocrine tumour cells.

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    Münzberg, Christin; Höhn, Katharina; Krndija, Denis; Maaß, Ulrike; Bartsch, Detlef K; Slater, Emily P; Oswald, Franz; Walther, Paul; Seufferlein, Thomas; von Wichert, Götz

    2015-05-01

    Hypersecretion is the major symptom of functional neuroendocrine tumours. The mechanisms that contribute to this excessive secretion of hormones are still elusive. A key event in secretion is the exit of secretory products from the Golgi apparatus. ADP-ribosylation factor (Arf) GTPases are known to control vesicle budding and trafficking, and have a leading function in the regulation of formation of secretory granula at the Golgi. Here, we show that Arf1 is the predominant Arf protein family member expressed in the neuroendocrine pancreatic tumour cell lines BON and QGP-1. In BON cells Arf1 colocalizes with Golgi markers as well as chromogranin A, and shows significant basal activity. The inhibition of Arf1 activity or expression significantly impaired secretion of chromogranin A. Furthermore, we show that the insulin-like growth factor 1 (IGF-1), a major regulator of growth and secretion in BON cells, induces Arf1 activity. We found that activation of Arf1 upon IGF-1 receptor stimulation is mediated by MEK/ERK signalling pathway in BON and QGP-1 cells. Moreover, the activity of Arf1 in BON cells is mediated by autocrinely secreted IGF-1, and concomitantly, autocrine IGF1 secretion is maintained by Arf1 activity. In summary, our data indicate an important regulatory role for Arf1 at the Golgi in hypersecretion in neuroendocrine cancer cells.

  14. The domain architecture of large guanine nucleotide exchange factors for the small GTP-binding protein Arf

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    Geldner Niko

    2005-02-01

    Full Text Available Abstract Background Small G proteins, which are essential regulators of multiple cellular functions, are activated by guanine nucleotide exchange factors (GEFs that stimulate the exchange of the tightly bound GDP nucleotide by GTP. The catalytic domain responsible for nucleotide exchange is in general associated with non-catalytic domains that define the spatio-temporal conditions of activation. In the case of small G proteins of the Arf subfamily, which are major regulators of membrane trafficking, GEFs form a heterogeneous family whose only common characteristic is the well-characterized Sec7 catalytic domain. In contrast, the function of non-catalytic domains and how they regulate/cooperate with the catalytic domain is essentially unknown. Results Based on Sec7-containing sequences from fully-annotated eukaryotic genomes, including our annotation of these sequences from Paramecium, we have investigated the domain architecture of large ArfGEFs of the BIG and GBF subfamilies, which are involved in Golgi traffic. Multiple sequence alignments combined with the analysis of predicted secondary structures, non-structured regions and splicing patterns, identifies five novel non-catalytic structural domains which are common to both subfamilies, revealing that they share a conserved modular organization. We also report a novel ArfGEF subfamily with a domain organization so far unique to alveolates, which we name TBS (TBC-Sec7. Conclusion Our analysis unifies the BIG and GBF subfamilies into a higher order subfamily, which, together with their being the only subfamilies common to all eukaryotes, suggests that they descend from a common ancestor from which species-specific ArfGEFs have subsequently evolved. Our identification of a conserved modular architecture provides a background for future functional investigation of non-catalytic domains.

  15. Candida albicans: adapting to succeed.

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    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.

  16. ArfGAP1 is a GTPase Activating Protein for LRRK2: Reciprocal Regulation of ArfGAP1 by LRRK2

    Science.gov (United States)

    Xiong, Yulan; Yuan, Changqing; Chen, Rong; Dawson, Ted M.; Dawson, Valina L.

    2012-01-01

    Both sporadic and autosomal dominant forms of Parkinson’s disease (PD) have been causally linked to mutations in leucine-rich repeat kinase 2 (LRRK2), a large protein with multiple domains. The kinase domain plays an important role in LRRK2 mediated toxicity. While a number of investigations have focused on LRRK2 kinase activity, less is known about the GTPase function of LRRK2. The activity of GTPases is regulated by GTPase activating proteins (GAPs) and GTP exchange factors (GEFs). Here, we identify ArfGAP1 as the first GAP for LRRK2. ArfGAP1 binds LRRK2 predominantly via the WD40 and kinase domain of LRRK2 and it increases LRRK2 GTPase activity and regulates LRRK2 toxicity both in vitro and in vivo in Drosophila melanogaster. Unexpectedly, ArfGAP1 is a LRRK2 kinase substrate whose GAP activity is inhibited by LRRK2, while wild type and G2019S LRRK2 autophosphorylation and kinase activity are significantly reduced in the presence of ArfGAP1. Overexpressed ArfGAP1 exhibits toxicity that is reduced by LRRK2 both in vitro and in vivo. Δ64-ArfGAP1, a dominant negative ArfGAP1, and shRNA knockdown of ArfGAP1 reduce LRRK2 toxicity. Thus, LRRK2 and ArfGAP1 reciprocally regulate the activity of each other. Our results provide insight into the basic pathobiology of LRRK2 and indicate an important role for the GTPase domain and ArfGAP1 in LRRK2 mediated toxicity. These data suggest that agents targeted towards regulation of LRRK2 GTP hydrolysis might be therapeutic agents for the treatment of Parkinson’s disease. PMID:22423108

  17. ARF: a versatile DNA damage response ally at the crossroads of development and tumorigenesis

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    Athanassios eKotsinas

    2014-07-01

    Full Text Available ARF is a tumor suppressor protein that senses oncogenic and other stressogenic signals. It can trigger p53-dependent and -independent responses with cell cycle arrest and apoptosis induction being the most prominent ones. Other ARF activities, particularly p53-independent ones, that could help in understanding cancer development and provide potential therapeutic exploitation are underrated. Although ARF is generally not expressed in normal tissues, it is essential for ocular and male germ cells development. The underlying mechanism(s in these processes, while not clearly defined, point towards a functional link between ARF, DNA damage and angiogenesis. Based on a recent study from our group demonstrating a functional interplay between ATM and ARF during carcinogenesis, we discuss the role of ARF at the crossroads of cancer and developmental processes.

  18. Expression of p16INK4A and p14ARF in hematological malignancies.

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    Taniguchi, T; Chikatsu, N; Takahashi, S; Fujita, A; Uchimaru, K; Asano, S; Fujita, T; Motokura, T

    1999-11-01

    The INK4A/ARF locus yields two tumor suppressors, p16INK4A and p14ARF, and is frequently deleted in human tumors. We studied their mRNA expressions in 41 hematopoietic cell lines and in 137 patients with hematological malignancies; we used a quantitative reverse transcription-PCR assay. Normal peripheral bloods, bone marrow and lymph nodes expressed little or undetectable p16INK4A and p14ARF mRNAs, which were readily detected in 12 and 17 of 41 cell lines, respectively. Patients with hematological malignancies frequently lacked p16INK4A expression (60/137) and lost p14ARF expression less frequently (19/137, 13.9%). Almost all patients without p14ARF expression lacked p16INK4A expression, which may correspond to deletions of the INK4A/ARF locus. Undetectable p16INK4A expression with p14ARF expression in 41 patients may correspond to p16INK4A promoter methylation or to normal expression status of the p16INK4A gene. All patients with follicular lymphoma (FL), myeloma or acute myeloid leukemia (AML) expressed p14ARF while nine of 23 patients with diffuse large B cell lymphoma (DLBCL) lost p14ARF expression. Patients with ALL, AML or blast crisis of chronic myelogenous leukemia expressed abundant p16INK4A mRNAs more frequently than patients with other diseases (12/33 vs 6/104, P < 0.01). Patients with FL and high p14ARF expression had a significantly shorter survival time while survival for patients with DLBCL and increased p14ARF expression tended to be longer. These observations indicate that p16INK4A and p14ARF expression is differentially affected among hemato- logical malignancies and that not only inactivation but also increased expression may have clinical significance.

  19. The Arf GTPase-Activating Protein Family Is Exploited by Salmonella enterica Serovar Typhimurium To Invade Nonphagocytic Host Cells

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    Davidson, Anthony C.; Humphreys, Daniel; Brooks, Andrew B. E.; Hume, Peter J.

    2015-01-01

    ABSTRACT To establish intracellular infections, Salmonella bacteria trigger host cell membrane ruffling and invasion by subverting cellular Arf guanine nucleotide exchange factors (GEFs) that activate Arf1 and Arf6 GTPases by promoting GTP binding. A family of cellular Arf GTPase-activating proteins (GAPs) can downregulate Arf signaling by stimulating GTP hydrolysis, but whether they do this during infection is unknown. Here, we uncovered a remarkable role for distinct Arf GAP family members in Salmonella invasion. The Arf6 GAPs ACAP1 and ADAP1 and the Arf1 GAP ASAP1 localized at Salmonella-induced ruffles, which was not the case for the plasma membrane-localized Arf6 GAPs ARAP3 and GIT1 or the Golgi-associated Arf1 GAP1. Surprisingly, we found that loss of ACAP1, ADAP1, or ASAP1 impaired Salmonella invasion, revealing that GAPs cannot be considered mere terminators of cytoskeleton remodeling. Salmonella invasion was restored in Arf GAP-depleted cells by expressing fast-cycling Arf derivatives, demonstrating that Arf GTP/GDP cycles facilitate Salmonella invasion. Consistent with this view, both constitutively active and dominant-negative Arf derivatives that cannot undergo GTP/GDP cycles inhibited invasion. Furthermore, we demonstrated that Arf GEFs and GAPs colocalize at invading Salmonella and collaborate to drive Arf1-dependent pathogen invasion. This study revealed that Salmonella bacteria exploit a remarkable interplay between Arf GEFs and GAPs to direct cycles of Arf GTPase activation and inactivation. These cycles drive Salmonella cytoskeleton remodeling and enable intracellular infections. PMID:25670778

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

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    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.

  1. The Guanine Nucleotide Exchange Factor ARNO mediates the activation of ARF and phospholipase D by insulin

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    Fluharty Eric

    2003-09-01

    Full Text Available Abstract Background Phospholipase D (PLD is involved in many signaling pathways. In most systems, the activity of PLD is primarily regulated by the members of the ADP-Ribosylation Factor (ARF family of GTPases, but the mechanism of activation of PLD and ARF by extracellular signals has not been fully established. Here we tested the hypothesis that ARF-guanine nucleotide exchange factors (ARF-GEFs of the cytohesin/ARNO family mediate the activation of ARF and PLD by insulin. Results Wild type ARNO transiently transfected in HIRcB cells was translocated to the plasma membrane in an insulin-dependent manner and promoted the translocation of ARF to the membranes. ARNO mutants: ΔCC-ARNO and CC-ARNO were partially translocated to the membranes while ΔPH-ARNO and PH-ARNO could not be translocated to the membranes. Sec7 domain mutants of ARNO did not facilitate the ARF translocation. Overexpression of wild type ARNO significantly increased insulin-stimulated PLD activity, and mutations in the Sec7 and PH domains, or deletion of the PH or CC domains inhibited the effects of insulin. Conclusions Small ARF-GEFs of the cytohesin/ARNO family mediate the activation of ARF and PLD by the insulin receptor.

  2. Arf4 is required for Mammalian development but dispensable for ciliary assembly.

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    John A Follit

    2014-02-01

    Full Text Available The primary cilium is a sensory organelle, defects in which cause a wide range of human diseases including retinal degeneration, polycystic kidney disease and birth defects. The sensory functions of cilia require specific receptors to be targeted to the ciliary subdomain of the plasma membrane. Arf4 has been proposed to sort cargo destined for the cilium at the Golgi complex and deemed a key regulator of ciliary protein trafficking. In this work, we show that Arf4 binds to the ciliary targeting sequence (CTS of fibrocystin. Knockdown of Arf4 indicates that it is not absolutely required for trafficking of the fibrocystin CTS to cilia as steady-state CTS levels are unaffected. However, we did observe a delay in delivery of newly synthesized CTS from the Golgi complex to the cilium when Arf4 was reduced. Arf4 mutant mice are embryonic lethal and die at mid-gestation shortly after node formation. Nodal cilia appeared normal and functioned properly to break left-right symmetry in Arf4 mutant embryos. At this stage of development Arf4 expression is highest in the visceral endoderm but we did not detect cilia on these cells. In the visceral endoderm, the lack of Arf4 caused defects in cell structure and apical protein localization. This work suggests that while Arf4 is not required for ciliary assembly, it is important for the efficient transport of fibrocystin to cilia, and also plays critical roles in non-ciliary processes.

  3. Arf6 regulates EGF-induced internalization of E-cadherin in breast cancer cells.

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    Xu, Rui; Zhang, Yujie; Gu, Luo; Zheng, Jianchao; Cui, Jie; Dong, Jing; Du, Jun

    2015-01-01

    E-cadherin internalization facilitates dissolution of adherens junctions and promotes tumor cell epithelial-mesenchymal transition (EMT) and migration. Our previous results have shown that Arf6 exerts pro-migratory action in breast cancer cells after EGF stimulation. Despite the fact that EGF signaling stimulates EMT of breast cancer cells, the effect of Arf6 on internalization of E-cadherin of breast cancer cells under EGF treatment remains to be determined. Here, we showed that EGF dose-dependently stimulated E-cadherin internalization by MCF-7 cells with the maximal effect at 50 ng/ml. Meanwhile, EGF treatment markedly increased Arf6 activation. Arf6 was involved in complexes of E-cadherin, and more E-cadherin was pulled down with Arf6 when the activity of the latter was increased. Immunoblotting and immunofluorescence assays showed that transfection breast cancer cells with Arf6-T27N or Arf6 siRNA suppressed EGF-induced E-cadherin internalization. Taken together, our study demonstrated that Arf6 activation plays a potential role in EGF-induced E-cadherin internalization, providing new mechanism underlying the effect of Arf6 on promoting breast cancer cell metastasis.

  4. The Guanine Nucleotide Exchange Factor ARNO mediates the activation of ARF and phospholipase D by insulin

    Science.gov (United States)

    Li, Hai-Sheng; Shome, Kuntala; Rojas, Raúl; Rizzo, Mark A; Vasudevan, Chandrasekaran; Fluharty, Eric; Santy, Lorraine C; Casanova, James E; Romero, Guillermo

    2003-01-01

    Background Phospholipase D (PLD) is involved in many signaling pathways. In most systems, the activity of PLD is primarily regulated by the members of the ADP-Ribosylation Factor (ARF) family of GTPases, but the mechanism of activation of PLD and ARF by extracellular signals has not been fully established. Here we tested the hypothesis that ARF-guanine nucleotide exchange factors (ARF-GEFs) of the cytohesin/ARNO family mediate the activation of ARF and PLD by insulin. Results Wild type ARNO transiently transfected in HIRcB cells was translocated to the plasma membrane in an insulin-dependent manner and promoted the translocation of ARF to the membranes. ARNO mutants: ΔCC-ARNO and CC-ARNO were partially translocated to the membranes while ΔPH-ARNO and PH-ARNO could not be translocated to the membranes. Sec7 domain mutants of ARNO did not facilitate the ARF translocation. Overexpression of wild type ARNO significantly increased insulin-stimulated PLD activity, and mutations in the Sec7 and PH domains, or deletion of the PH or CC domains inhibited the effects of insulin. Conclusions Small ARF-GEFs of the cytohesin/ARNO family mediate the activation of ARF and PLD by the insulin receptor. PMID:12969509

  5. High yield production of myristoylated Arf6 small GTPase by recombinant N-myristoyl transferase

    Science.gov (United States)

    Padovani, Dominique; Zeghouf, Mahel; Traverso, José A.; Giglione, Carmela; Cherfils, Jacqueline

    2013-01-01

    Small GTP-binding proteins of the Arf family (Arf GTPases) interact with multiple cellular partners and with membranes to regulate intracellular traffic and organelle structure. Understanding the underlying molecular mechanisms requires in vitro biochemical assays to test for regulations and functions. Such assays should use proteins in their cellular form, which carry a myristoyl lipid attached in N-terminus. N-myristoylation of recombinant Arf GTPases can be achieved by co-expression in E. coli with a eukaryotic N-myristoyl transferase. However, purifying myristoylated Arf GTPases is difficult and has a poor overall yield. Here we show that human Arf6 can be N-myristoylated in vitro by recombinant N-myristoyl transferases from different eukaryotic species. The catalytic efficiency depended strongly on the guanine nucleotide state and was highest for Arf6-GTP. Large-scale production of highly pure N-myristoylated Arf6 could be achieved, which was fully functional for liposome-binding and EFA6-stimulated nucleotide exchange assays. This establishes in vitro myristoylation as a novel and simple method that could be used to produce other myristoylated Arf and Arf-like GTPases for biochemical assays. PMID:23319116

  6. Expression of arf tumor suppressor in spermatogonia facilitates meiotic progression in male germ cells.

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    Michelle L Churchman

    2011-07-01

    Full Text Available The mammalian Cdkn2a (Ink4a-Arf locus encodes two tumor suppressor proteins (p16(Ink4a and p19(Arf that respectively enforce the anti-proliferative functions of the retinoblastoma protein (Rb and the p53 transcription factor in response to oncogenic stress. Although p19(Arf is not normally detected in tissues of young adult mice, a notable exception occurs in the male germ line, where Arf is expressed in spermatogonia, but not in meiotic spermatocytes arising from them. Unlike other contexts in which the induction of Arf potently inhibits cell proliferation, expression of p19(Arf in spermatogonia does not interfere with mitotic cell division. Instead, inactivation of Arf triggers germ cell-autonomous, p53-dependent apoptosis of primary spermatocytes in late meiotic prophase, resulting in reduced sperm production. Arf deficiency also causes premature, elevated, and persistent accumulation of the phosphorylated histone variant H2AX, reduces numbers of chromosome-associated complexes of Rad51 and Dmc1 recombinases during meiotic prophase, and yields incompletely synapsed autosomes during pachynema. Inactivation of Ink4a increases the fraction of spermatogonia in S-phase and restores sperm numbers in Ink4a-Arf doubly deficient mice but does not abrogate γ-H2AX accumulation in spermatocytes or p53-dependent apoptosis resulting from Arf inactivation. Thus, as opposed to its canonical role as a tumor suppressor in inducing p53-dependent senescence or apoptosis, Arf expression in spermatogonia instead initiates a salutary feed-forward program that prevents p53-dependent apoptosis, contributing to the survival of meiotic male germ cells.

  7. 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.

  8. A short acidic motif in ARF guards against mitochondrial dysfunction and melanoma susceptibility

    DEFF Research Database (Denmark)

    Christensen, Claus; Bartkova, Jirina; Mistrík, Martin

    2014-01-01

    ARF is a small, highly basic protein that can be induced by oncogenic stimuli and exerts growth-inhibitory and tumour-suppressive activities through the activation of p53. Here we show that, in human melanocytes, ARF is cytoplasmic, constitutively expressed, and required for maintaining low steady...

  9. AKT regulates NPM dependent ARF localization and p53mut stability in tumors.

    Science.gov (United States)

    Hamilton, Garth; Abraham, Aswin G; Morton, Jennifer; Sampson, Oliver; Pefani, Dafni E; Khoronenkova, Svetlana; Grawenda, Anna; Papaspyropoulos, Angelos; Jamieson, Nigel; McKay, Colin; Sansom, Owen; Dianov, Grigory L; O'Neill, Eric

    2014-08-15

    Nucleophosmin (NPM) is known to regulate ARF subcellular localization and MDM2 activity in response to oncogenic stress, though the precise mechanism has remained elusive. Here we describe how NPM and ARF associate in the nucleoplasm to form a MDM2 inhibitory complex. We find that oligomerization of NPM drives nucleolar accumulation of ARF. Moreover, the formation of NPM and ARF oligomers antagonizes MDM2 association with the inhibitory complex, leading to activation of MDM2 E3-ligase activity and targeting of p53. We find that AKT phosphorylation of NPM-Ser48 prevents oligomerization that results in nucleoplasmic localization of ARF, constitutive MDM2 inhibition and stabilization of p53. We also show that ARF promotes p53 mutant stability in tumors and suppresses p73 mediated p21 expression and senescence. We demonstrate that AKT and PI3K inhibitors may be effective in treatment of therapeutically resistant tumors with elevated AKT and carrying gain of function mutations in p53. Our results show that the clinical candidate AKT inhibitor MK-2206 promotes ARF nucleolar localization, reduced p53(mut) stability and increased sensitivity to ionizing radiation in a xenograft model of pancreatic cancer. Analysis of human tumors indicates that phospho-S48-NPM may be a useful biomarker for monitoring AKT activity and in vivo efficacy of AKT inhibitor treatment. Critically, we propose that combination therapy involving PI3K-AKT inhibitors would benefit from a patient stratification rationale based on ARF and p53(mut) status.

  10. Physiological functions of the small GTPase Arf6 in the nervous system.

    Science.gov (United States)

    Akiyama, Masahiro; Kanaho, Yasunori

    2015-01-01

    The small GTPase ADP-ribosylation factor 6 (Arf6) plays important roles in membrane dynamics-based neuronal cell events such as neurite outgrowth and spine formation. However, physiological functions of Arf6 in the nervous system at whole animal level have not yet been explored. We have recently generated conditional knockout mice lacking Arf6 in neurons or oligodendrocytes of central nervous system (CNS) or both cell lineages, and analyzed them. We found that ablation of Arf6 gene from neurons, but not from oligodendrocytes, caused the defect in axon myelination at the fimbria of hippocampus (Fim) and corpus callosum (CC). We also found that migration of oligodendrocyte precursor cells (OPCs) from the subventricular zone to the Fim and CC in mice lacking Arf6 in neurons was impaired. Finally, it was found that secretion of fibroblast growth factor-2 (FGF-2), a guidance factor for OPC migration, from hippocampi lacking Arf6 was impaired. Collectively, these findings demonstrate that Arf6 in neurons of the CNS plays an important role in OPC migration by regulating secretion of FGF-2 from neurons, thereby contributing to the axon myelination. Here, we discuss our current understanding of physiological functions of Arf6 in the nervous system.

  11. Membrane association of the Arabidopsis ARF exchange factor GNOM involves interaction of conserved domains

    DEFF Research Database (Denmark)

    Anders, Nadine; Nielsen, Michael M.; Keicher, Jutta;

    2008-01-01

    The GNOM protein plays a fundamental role in Arabidopsis thaliana development by regulating endosome-to-plasma membrane trafficking required for polar localization of the auxin efflux carrier PIN1. GNOM is a family member of large ARF guanine nucleotide exchange factors (ARF-GEFs), which regulate...

  12. 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...

  13. HYPERMETHYLATION OF p14ARF PROMOTER REGION AND EXPRESION OF p14ARF GENE PRODUCT IN NON-SMALL CELL LUNG CANCER

    Institute of Scientific and Technical Information of China (English)

    TIAN Kai-hua; SHEN Yi; LUO Yi-rne; WANG Ming-zhao; LIU Hong-xu; ZHAO Hui-ru; ZHANG Lin

    2006-01-01

    Objective: This study was designed to investigate promoter methylation status and protein expression of p14ARF gene in non-small cell lung cancer, and value the role of p14ARF promoter methylation in carcinogenesis of non-small cell lung cancer. Methods: Promoter methylation status and protein expression of p14ARF gene in 40 cases of non-small cell lung cancer were analyzed by methylation specific polymerase china reaction (MSP), restriction enzyme-related polymerase chain reaction (RE-PCR) and immunohistochemistry (IHC). Results: The positive rates of p14ARF promoter methylation in tumor tissues and normal tissues adjacent to cancer were 17.5% (7/40) and 2.5% (1/40) respectively. There were statistically significant differences between them, P<0.05. The results of RE-PCR were consistent with that of MSP. The expression rate of p14ARF protein in tumor tissues was significantly lower than that in normal tissues adjacent to cancer, p<0.01. Promoter methylation status and protein expression of p14ARF gene in non-small cell lung cancer showed significantly an inverse correlation (r=-0.56, P<0.01), and both of them did not relate statistically with the clinicopathologic characteristics of patients such as histological classification, clinical stage, differentiation grade and lymph node involvement. Conclusion: Promoter methylation is a crucial mechanism of inactivation of p14ARF gene. Promoter methylation of p14ARF gene might be involved in carcinogenesis of non-small cell lung cancer, and is an early event in development process of non-small cell lung cancer. It might be used as a new target in gene treatments in the future.

  14. Genome-wide analysis of Aux/IAA and ARF gene families in Populus trichocarpa

    Energy Technology Data Exchange (ETDEWEB)

    Kalluri, Udaya C [ORNL; DiFazio, Stephen P [West Virginia University; Brunner, A. [Virginia Polytechnic Institute and State University (Virginia Tech); Tuskan, Gerald A [ORNL

    2007-01-01

    Auxin/Indole-3-Acetic Acid (Aux/IAA) and Auxin Response Factor (ARF) transcription factors are key regulators of auxin responses in plants. A total of 35 Aux/IAA and 39 ARF genes were identified in the Populus genome. Comparative phylogenetic analysis revealed that the subgroups PoptrARF2, 6, 9 and 16 and PoptrIAA3, 16, 27 and 29 have differentially expanded in Populus relative to Arabidopsis. Activator ARFs were found to be two fold-overrepresented in the Populus genome. PoptrIAA and PoptrARF gene families appear to have expanded due to high segmental and low tandem duplication events. Furthermore, expression studies showed that genes in the expanded PoptrIAA3 subgroup display differential expression. The gene-family analysis reported here will be useful in conducting future functional genomics studies to understand how the molecular roles of these large gene families translate into a diversity of biologically meaningful auxin effects.

  15. Regulators and Effectors of Arf GTPases in Neutrophils.

    Science.gov (United States)

    Gamara, Jouda; Chouinard, François; Davis, Lynn; Aoudjit, Fawzi; Bourgoin, Sylvain G

    2015-01-01

    Polymorphonuclear neutrophils (PMNs) are key innate immune cells that represent the first line of defence against infection. They are the first leukocytes to migrate from the blood to injured or infected sites. This process involves molecular mechanisms that coordinate cell polarization, delivery of receptors, and activation of integrins at the leading edge of migrating PMNs. These phagocytes actively engulf microorganisms or form neutrophil extracellular traps (NETs) to trap and kill pathogens with bactericidal compounds. Association of the NADPH oxidase complex at the phagosomal membrane for production of reactive oxygen species (ROS) and delivery of proteolytic enzymes into the phagosome initiate pathogen killing and removal. G protein-dependent signalling pathways tightly control PMN functions. In this review, we will focus on the small monomeric GTPases of the Arf family and their guanine exchange factors (GEFs) and GTPase activating proteins (GAPs) as components of signalling cascades regulating PMN responses. GEFs and GAPs are multidomain proteins that control cellular events in time and space through interaction with other proteins and lipids inside the cells. The number of Arf GAPs identified in PMNs is expanding, and dissecting their functions will provide important insights into the role of these proteins in PMN physiology.

  16. Regulators and Effectors of Arf GTPases in Neutrophils

    Directory of Open Access Journals (Sweden)

    Jouda Gamara

    2015-01-01

    Full Text Available Polymorphonuclear neutrophils (PMNs are key innate immune cells that represent the first line of defence against infection. They are the first leukocytes to migrate from the blood to injured or infected sites. This process involves molecular mechanisms that coordinate cell polarization, delivery of receptors, and activation of integrins at the leading edge of migrating PMNs. These phagocytes actively engulf microorganisms or form neutrophil extracellular traps (NETs to trap and kill pathogens with bactericidal compounds. Association of the NADPH oxidase complex at the phagosomal membrane for production of reactive oxygen species (ROS and delivery of proteolytic enzymes into the phagosome initiate pathogen killing and removal. G protein-dependent signalling pathways tightly control PMN functions. In this review, we will focus on the small monomeric GTPases of the Arf family and their guanine exchange factors (GEFs and GTPase activating proteins (GAPs as components of signalling cascades regulating PMN responses. GEFs and GAPs are multidomain proteins that control cellular events in time and space through interaction with other proteins and lipids inside the cells. The number of Arf GAPs identified in PMNs is expanding, and dissecting their functions will provide important insights into the role of these proteins in PMN physiology.

  17. Arf6 coordinates actin assembly through the WAVE complex, a mechanism usurped by Salmonella to invade host cells

    Science.gov (United States)

    Humphreys, Daniel; Davidson, Anthony C.; Hume, Peter J.; Makin, Laura E.; Koronakis, Vassilis

    2013-01-01

    ADP ribosylation factor (Arf) 6 anchors to the plasma membrane, where it coordinates membrane trafficking and cytoskeleton remodelling, but how it assembles actin filaments is unknown. By reconstituting membrane-associated actin assembly mediated by the WASP family veroprolin homolog (WAVE) regulatory complex (WRC), we recapitulated an Arf6-driven actin polymerization pathway. We show that Arf6 is divergent from other Arf members, as it was incapable of directly recruiting WRC. We demonstrate that Arf6 triggers actin assembly at the membrane indirectly by recruiting the Arf guanine nucleotide exchange factor (GEF) ARNO that activates Arf1 to enable WRC-dependent actin assembly. The pathogen Salmonella usurped Arf6 for host cell invasion by recruiting its canonical GEFs EFA6 and BRAG2. Arf6 and its GEFs facilitated membrane ruffling and pathogen invasion via ARNO, and triggered actin assembly by generating an Arf1–WRC signaling hub at the membrane in vitro and in cells. This study reconstitutes Arf6-dependent actin assembly to reveal a mechanism by which related Arf GTPases orchestrate distinct steps in the WRC cytoskeleton remodelling pathway. PMID:24085844

  18. 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

  19. 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.

  20. 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...

  1. 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.

  2. Molecular analysis of ARF1 expression profiles during development of physic nut (Jatropha curcas L.).

    Science.gov (United States)

    Qin, Xiaobo; Lin, Fanrong; Lii, Yifan; Gou, Chunbao; Chen, Fang

    2011-03-01

    A cDNA clone designated arf1 was isolated from a physic nut (Jatropha curcas L.) endosperm cDNA library which encodes a small GTP-binding protein and has significant homology to ADP-ribosylation factors (ARF) in plants, animals and microbes. The cDNA contains an open reading frame that encodes a polypeptide of 181 amino acids with a calculated molecular mass of 20.7 kDa. The deduced amino acid sequence showed high homology to known ARFs from other organisms. The products of the arf1 obtained by overexpression in E. coli revealed the specific binding activity toward GTP. The expression of arf1 was observed in flowers, roots, stems and leaves as analyzed by RT-PCR, and its transcriptional level was highest in flowers. In particular, the accumulation of arf1 transcripts was different under various environmental stresses in seedlings. The results suggest that arf1 plays distinct physiological roles in Jatropha curcas cells.

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

    Science.gov (United States)

    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.

  4. Neon reduction program on Cymer ArF light sources

    Science.gov (United States)

    Kanawade, Dinesh; Roman, Yzzer; Cacouris, Ted; Thornes, Josh; O'Brien, Kevin

    2016-03-01

    In response to significant neon supply constraints, Cymer has responded with a multi-part plan to support its customers. Cymer's primary objective is to ensure that reliable system performance is maintained while minimizing gas consumption. Gas algorithms were optimized to ensure stable performance across all operating conditions. The Cymer neon support plan contains four elements: 1. Gas reduction program to reduce neon by >50% while maintaining existing performance levels and availability; 2. short-term containment solutions for immediate relief. 3. qualification of additional gas suppliers; and 4. long-term recycling/reclaim opportunity. The Cymer neon reduction program has shown excellent results as demonstrated through the comparison on standard gas use versus the new >50% reduced neon performance for ArF immersion light sources. Testing included stressful conditions such as repetition rate, duty cycle and energy target changes. No performance degradation has been observed over typical gas lives.

  5. Genome-wide identification, isolation and expression analysis of auxin response factor (ARF) gene family in sweet orange (Citrus sinensis).

    Science.gov (United States)

    Li, Si-Bei; OuYang, Wei-Zhi; Hou, Xiao-Jin; Xie, Liang-Liang; Hu, Chun-Gen; Zhang, Jin-Zhi

    2015-01-01

    Auxin response factors (ARFs) are an important family of proteins in auxin-mediated response, with key roles in various physiological and biochemical processes. To date, a genome-wide overview of the ARF gene family in citrus was not available. A systematic analysis of this gene family in citrus was begun by carrying out a genome-wide search for the homologs of ARFs. A total of 19 nonredundant ARF genes (CiARF) were found and validated from the sweet orange. A comprehensive overview of the CiARFs was undertaken, including the gene structures, phylogenetic analysis, chromosome locations, conserved motifs of proteins, and cis-elements in promoters of CiARF. Furthermore, expression profiling using real-time PCR revealed many CiARF genes, albeit with different patterns depending on types of tissues and/or developmental stages. Comprehensive expression analysis of these genes was also performed under two hormone treatments using real-time PCR. Indole-3-acetic acid (IAA) and N-1-napthylphthalamic acid (NPA) treatment experiments revealed differential up-regulation and down-regulation, respectively, of the 19 citrus ARF genes in the callus of sweet orange. Our comprehensive analysis of ARF genes further elucidates the roles of CiARF family members during citrus growth and development process.

  6. p14ARF upregulation of p53 and enhanced effects of 5-fluorouracil in pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    张群华; 倪泉兴; 甘军; 沈兆忠; 罗建民; 金忱; 张妞; 张延龄

    2003-01-01

    Objective To investigate the synergistic antitumor effects of combined use of p14ARF gene and 5-fluorouracil (5-Fu) in pancreatic cancer.Methods A human pancreatic cancer cell line PC-3 was transfected with lipofectin-mediated recombinant p14ARF gene, and was then administered with 5-Fu. Cell growth, morphological changes, cell cycle, apoptosis, and molecular changes were measured using the MTT assay, flow cytometry, RT-PCR, Western blotting, and immunocytochemical assays.Results After transfection of p14ARF, cell growth was obviously inhibited, resulting in an accumulation of cells in the G1 phase. The proportion of cells in the G1 phase was significantly increased from 58.51% to 75.92 %, and in the S and G2/M phases decreased significantly from 20.05% to 12.60%, and from 21.44% to 11.48 %, respectively, as compared with those of the control groups. PC-3/p14ARF cells that underwent 5-Fu treatment had significantly greater G2/M phase accumulation, from 11.48% to 53.47 %. The apoptopic index was increased in PC-3/p14ARF cells from 3.64% to 19.62%. The MTT assay showed p14ARF-expressing cells were significantly more sensitive to 5-Fu (0.01-10 mg/L) than those devoid of p14ARF expression (P<0.01). Western blotting showed p14ARF upregulates p53 expression. Conclusion Combined use of p14ARF gene and 5-Fu acts synergistically to inhibit pancreatic cancer cell proliferation, suggesting a new anticancer strategy.

  7. The DNA damage checkpoint precedes activation of ARF in response to escalating oncogenic stress during tumorigenesis

    DEFF Research Database (Denmark)

    Evangelou, K; Bartkova, J; Kotsinas, A

    2013-01-01

    Oncogenic stimuli trigger the DNA damage response (DDR) and induction of the alternative reading frame (ARF) tumor suppressor, both of which can activate the p53 pathway and provide intrinsic barriers to tumor progression. However, the respective timeframes and signal thresholds for ARF induction...... or p16INK4A, a tumor-suppressor gene overlapping with ARF. Analogous results were obtained in several human clinical settings, including early and progressive lesions of the urinary bladder, head and neck, skin and pancreas. Mechanistic analyses of epithelial and fibroblast cell models exposed...

  8. 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

  9. Structurally Distinct Bacterial TBC-like GAPs Link Arf GTPase to Rab1 Inactivation to Counteract Host Defenses

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Na; Zhu, Yongqun; Lu, Qiuhe; Hu, Liyan; Zheng, Yuqing; Shao, Feng (NIBS-China); (Zhejiang)

    2012-10-10

    Rab GTPases are frequent targets of vacuole-living bacterial pathogens for appropriate trafficking of the vacuole. Here we discover that bacterial effectors including VirA from nonvacuole Shigella flexneri and EspG from extracellular Enteropathogenic Escherichia coli (EPEC) harbor TBC-like dual-finger motifs and exhibits potent RabGAP activities. Specific inactivation of Rab1 by VirA/EspG disrupts ER-to-Golgi trafficking. S. flexneri intracellular persistence requires VirA TBC-like GAP activity that mediates bacterial escape from autophagy-mediated host defense. Rab1 inactivation by EspG severely blocks host secretory pathway, resulting in inhibited interleukin-8 secretion from infected cells. Crystal structures of VirA/EspG-Rab1-GDP-aluminum fluoride complexes highlight TBC-like catalytic role for the arginine and glutamine finger residues and reveal a 3D architecture distinct from that of the TBC domain. Structure of Arf6-EspG-Rab1 ternary complex illustrates a pathogenic signaling complex that rewires host Arf signaling to Rab1 inactivation. Structural distinctions of VirA/EspG further predict a possible extensive presence of TBC-like RabGAP effectors in counteracting various host defenses.

  10. ARF1 and SAR1 GTPases in endomembrane trafficking in plants.

    Science.gov (United States)

    Cevher-Keskin, Birsen

    2013-09-05

    Small GTPases largely control membrane traffic, which is essential for the survival of all eukaryotes. Among the small GTP-binding proteins, ARF1 (ADP-ribosylation factor 1) and SAR1 (Secretion-Associated RAS super family 1) are commonly conserved among all eukaryotes with respect to both their functional and sequential characteristics. The ARF1 and SAR1 GTP-binding proteins are involved in the formation and budding of vesicles throughout plant endomembrane systems. ARF1 has been shown to play a critical role in COPI (Coat Protein Complex I)-mediated retrograde trafficking in eukaryotic systems, whereas SAR1 GTPases are involved in intracellular COPII-mediated protein trafficking from the ER to the Golgi apparatus. This review offers a summary of vesicular trafficking with an emphasis on the ARF1 and SAR1 expression patterns at early growth stages and in the de-etiolation process.

  11. 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.

  12. 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.

  13. Auxin Response Factor SlARF2 Is an Essential Component of the Regulatory Mechanism Controlling Fruit Ripening in Tomato.

    Science.gov (United States)

    Hao, Yanwei; Hu, Guojian; Breitel, Dario; Liu, Mingchun; Mila, Isabelle; Frasse, Pierre; Fu, Yongyao; Aharoni, Asaph; Bouzayen, Mondher; Zouine, Mohamed

    2015-12-01

    Ethylene is the main regulator of climacteric fruit ripening, by contrast the putative role of other phytohormones in this process remains poorly understood. The present study brings auxin signaling components into the mechanism regulating tomato fruit ripening through the functional characterization of Auxin Response Factor2 (SlARF2) which encodes a downstream component of auxin signaling. Two paralogs, SlARF2A and SlARF2B, are found in the tomato genome, both displaying a marked ripening-associated expression but distinct responsiveness to ethylene and auxin. Down-regulation of either SlARF2A or SlARF2B resulted in ripening defects while simultaneous silencing of both genes led to severe ripening inhibition suggesting a functional redundancy among the two ARFs. Tomato fruits under-expressing SlARF2 produced less climacteric ethylene and exhibited a dramatic down-regulation of the key ripening regulators RIN, CNR, NOR and TAGL1. Ethylene treatment failed to reverse the non-ripening phenotype and the expression of ethylene signaling and biosynthesis genes was strongly altered in SlARF2 down-regulated fruits. Although both SlARF proteins are transcriptional repressors the data indicate they work as positive regulators of tomato fruit ripening. Altogether, the study defines SlARF2 as a new component of the regulatory network controlling the ripening process in tomato.

  14. Auxin Response Factor SlARF2 Is an Essential Component of the Regulatory Mechanism Controlling Fruit Ripening in Tomato.

    Directory of Open Access Journals (Sweden)

    Yanwei Hao

    2015-12-01

    Full Text Available Ethylene is the main regulator of climacteric fruit ripening, by contrast the putative role of other phytohormones in this process remains poorly understood. The present study brings auxin signaling components into the mechanism regulating tomato fruit ripening through the functional characterization of Auxin Response Factor2 (SlARF2 which encodes a downstream component of auxin signaling. Two paralogs, SlARF2A and SlARF2B, are found in the tomato genome, both displaying a marked ripening-associated expression but distinct responsiveness to ethylene and auxin. Down-regulation of either SlARF2A or SlARF2B resulted in ripening defects while simultaneous silencing of both genes led to severe ripening inhibition suggesting a functional redundancy among the two ARFs. Tomato fruits under-expressing SlARF2 produced less climacteric ethylene and exhibited a dramatic down-regulation of the key ripening regulators RIN, CNR, NOR and TAGL1. Ethylene treatment failed to reverse the non-ripening phenotype and the expression of ethylene signaling and biosynthesis genes was strongly altered in SlARF2 down-regulated fruits. Although both SlARF proteins are transcriptional repressors the data indicate they work as positive regulators of tomato fruit ripening. Altogether, the study defines SlARF2 as a new component of the regulatory network controlling the ripening process in tomato.

  15. p19Arf suppresses growth, progression, and metastasis of Hras-driven carcinomas through p53-dependent and -independent pathways.

    Directory of Open Access Journals (Sweden)

    Karen S Kelly-Spratt

    2004-08-01

    Full Text Available Ectopic expression of oncogenes such as Ras induces expression of p19(Arf, which, in turn, activates p53 and growth arrest. Here, we used a multistage model of squamous cell carcinoma development to investigate the functional interactions between Ras, p19(Arf, and p53 during tumor progression in the mouse. Skin tumors were induced in wild-type, p19(Arf-deficient, and p53-deficient mice using the DMBA/TPA two-step protocol. Activating mutations in Hras were detected in all papillomas and carcinomas examined, regardless of genotype. Relative to wild-type mice, the growth rate of papillomas was greater in p19(Arf-deficient mice, and reduced in p53-deficient mice. Malignant conversion of papillomas to squamous cell carcinomas, as well as metastasis to lymph nodes and lungs, was markedly accelerated in both p19 (Arf- and p53-deficient mice. Thus, p19(Arf inhibits the growth rate of tumors in a p53-independent manner. Through its regulation of p53, p19(Arf also suppresses malignant conversion and metastasis. p53 expression was upregulated in papillomas from wild-type but not p19( Arf-null mice, and p53 mutations were more frequently seen in wild-type than in p19( Arf-null carcinomas. This indicates that selection for p53 mutations is a direct result of signaling from the initiating oncogenic lesion, Hras, acting through p19(Arf.

  16. 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...

  17. Effect of cell cycle inhibitor p19ARF on senescence of human diploid cell

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To investigate the effect of cell cycle inhibitor p19ARF on replicative senescence of human diploid cell, recombinant p19ARF eukaryotic expression vector was constructed and p19ARF gene was transfected into human diploid fibroblasts (WI-38 cells) by liposome-mediated transfection for overexpression. Then, the effects of p19ARF on replicative senescence of WI-38 cells were observed. The results re- vealed that, compared with control cells, the WI-38 cells in which p19ARF gene was introduced showed significant up-regulation of p53 and p21 expression level, decrease of cell generation by 10 12 generations, decline of cell growth rate with cell cycle being arrested at G1 phase, increase of positive rate of senescent marker SA-β-gal staining, and decrease of mitochondrial membrane potential. The morphology of the transfected fibroblasts presented the characteristics changes similar to senescent cells. These results indicated that high expression of p19ARF may promote the senescent process of human diploid cells.

  18. INK4/ARF transcript expression is associated with chromosome 9p21 variants linked to atherosclerosis.

    Directory of Open Access Journals (Sweden)

    Yan Liu

    Full Text Available Genome-wide association studies (GWAS have linked common single nucleotide polymorphisms (SNPs on chromosome 9p21 near the INK4/ARF (CDKN2A/B tumor suppressor locus with risk of atherosclerotic diseases and type 2 diabetes mellitus. To explore the mechanism of this association, we investigated whether expression of proximate transcripts (p16(INK4a, p15(INK4b, ARF, ANRIL and MTAP correlate with genotype of representative 9p21 SNPs.We analyzed expression of 9p21 transcripts in purified peripheral blood T-cells (PBTL from 170 healthy donors. Samples were genotyped for six selected disease-related SNPs spanning the INK4/ARF locus. Correlations among these variables were determined by univariate and multivariate analysis. Significantly reduced expression of all INK4/ARF transcripts (p15(INK4b, p16(INK4a, ARF and ANRIL was found in PBTL of individuals harboring a common SNP (rs10757278 associated with increased risk of coronary artery disease, stroke and aortic aneurysm. Expression of MTAP was not influenced by rs10757278 genotype. No association of any these transcripts was noted with five other tested 9p21 SNPs.Genotypes of rs10757278 linked to increased risk of atherosclerotic diseases are also associated with decreased expression in PBTL of the INK4/ARF locus, which encodes three related anti-proliferative transcripts of known importance in tumor suppression and aging.

  19. Golgi enlargement in Arf-depleted yeast cells is due to altered dynamics of cisternal maturation

    Science.gov (United States)

    Bhave, Madhura; Papanikou, Effrosyni; Iyer, Prasanna; Pandya, Koushal; Jain, Bhawik Kumar; Ganguly, Abira; Sharma, Chandrakala; Pawar, Ketakee; Austin, Jotham; Day, Kasey J.; Rossanese, Olivia W.; Glick, Benjamin S.; Bhattacharyya, Dibyendu

    2014-01-01

    ABSTRACT Regulation of the size and abundance of membrane compartments is a fundamental cellular activity. In Saccharomyces cerevisiae, disruption of the ADP-ribosylation factor 1 (ARF1) gene yields larger and fewer Golgi cisternae by partially depleting the Arf GTPase. We observed a similar phenotype with a thermosensitive mutation in Nmt1, which myristoylates and activates Arf. Therefore, partial depletion of Arf is a convenient tool for dissecting mechanisms that regulate Golgi structure. We found that in arf1Δ cells, late Golgi structure is particularly abnormal, with the number of late Golgi cisternae being severely reduced. This effect can be explained by selective changes in cisternal maturation kinetics. The arf1Δ mutation causes early Golgi cisternae to mature more slowly and less frequently, but does not alter the maturation of late Golgi cisternae. These changes quantitatively explain why late Golgi cisternae are fewer in number and correspondingly larger. With a stacked Golgi, similar changes in maturation kinetics could be used by the cell to modulate the number of cisternae per stack. Thus, the rates of processes that transform a maturing compartment can determine compartmental size and copy number. PMID:24190882

  20. 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.

  1. 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 ...

  2. 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.

  3. Mutational status of overexpressed p16 in head and neck cancer: evidence for germline mutation of p16/p14ARF.

    Science.gov (United States)

    Lang, J C; Borchers, J; Danahey, D; Smith, S; Stover, D G; Agrawal, A; Malone, J P; Schuller, D E; Weghorst, C M; Holinga, A J; Lingam, K; Patel, C R; Esham, B

    2002-08-01

    Inactivation of the p16 tumor suppressor gene is a common phenomenon in squamous cell carcinoma of the head and neck (SCCHN). Less commonly described is the observation of p16 overexpression in SCCHN. Since overexpression of p16 is a potent predictor of outcome in other cancers, we were interested in determining the level of expression of p16 in our SCCHN specimens as a prerequisite to later prognostic studies. We were also interested in determining the mutational status of p16 in these tumors, in order to determine whether the combination of overexpression and gene alteration may predict a different clinical outcome from overexpression alone. A total of 84 specimens of SCCHN were selected for study. These specimens were obtained from all major sites within the oral cavity, oropharynx, pharynx and larynx. The level of expression of p16 in SCCHN specimens was measured by semi-quantitative RT-PCR. In 35 cases, RNA was also isolated from matched normal tissue obtained from a negative tumor margin. In the other 49 cases, the expression level was compared with the level of expression measured in pooled normal RNA obtained from 10 specimens of normal epithelial tissue. Overexpression of p16 was documented when the level of expression in the tumor specimen was 2-fold or greater above the level of expression found in normal tissue. A total of 46 specimens demonstrated overexpression of p16 (55%). All specimens demonstrating overexpression were then subject to sequence analysis. Thirty specimens (65%) showed p16-specific gene alterations, ranging from intragenic deletions to single point mutations, and 15 of these cases concomitantly affect p14ARF. A single specimen demonstrated a silent point mutation within the p16 reading frame. This mutation produces a stop codon at residue 85 in the context of the p14ARF reading frame, predicting premature termination of p14ARF within a previously determined nucleolar localization signal. This observation suggests that in some cases at

  4. 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.

  5. 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.

  6. E2F-dependent induction of p14ARF during cell cycle re-entry in human T cells

    DEFF Research Database (Denmark)

    del Arroyo, Ana Gutierrez; El Messaoudi, Selma; Clark, Paula A

    2007-01-01

    The ARF protein, encoded by alternate exon usage within the CDKN2A locus, provides a link between the retinoblastoma (pRb) and p53 tumor suppressor pathways. Agents that disable pRb or otherwise impinge on the E2F family of transcription factors induce expression of ARF, resulting in stabilization...... of p53 and activation of p53-regulated genes. However, in some cell types ARF is not induced upon cell cycle re-entry, as expected of a conventional E2F target gene, leading to the suggestion that the ARF promoter only responds to supra-physiological or aberrant levels of E2F. These properties have...

  7. CDK5RAP3 is a novel repressor of p14ARF in hepatocellular carcinoma cells.

    Science.gov (United States)

    Mak, Grace Wing-Yan; Lai, Wai-Lung; Zhou, Yuan; Li, Mingtao; Ng, Irene Oi-Lin; Ching, Yick-Pang

    2012-01-01

    CDK5 regulatory subunit associated protein 3 (CDK5RAP3) is a novel activator of PAK4 and processes important pro-metastatic function in hepatocarcinogenesis. However, it remains unclear if there are other mechanisms by which CDK5RAP3 promotes HCC metastasis. Here, we showed that in CDK5RAP3 stable knockdown SMMC-7721 HCC cells, p14(ARF) tumor suppressor was upregulated at protein and mRNA levels, and ectopic expression of CDK5RAP3 was found to repress the transcription of p14(ARF). Using chromatin immunoprecipitation assay, we demonstrated that CDK5RAP3 bound to p14(ARF) promoter in vivo. Furthermore, knockdown of p14(ARF) in CDK5RAP3 stable knockdown HCC cells reversed the suppression of HCC cell invasiveness mediated by knockdown of CDK5RAP3. Taken together, our findings provide the new evidence that overexpression of CDK5RAP3 promotes HCC metastasis via downregulation of p14(ARF).

  8. CDK5RAP3 is a novel repressor of p14ARF in hepatocellular carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Grace Wing-Yan Mak

    Full Text Available CDK5 regulatory subunit associated protein 3 (CDK5RAP3 is a novel activator of PAK4 and processes important pro-metastatic function in hepatocarcinogenesis. However, it remains unclear if there are other mechanisms by which CDK5RAP3 promotes HCC metastasis. Here, we showed that in CDK5RAP3 stable knockdown SMMC-7721 HCC cells, p14(ARF tumor suppressor was upregulated at protein and mRNA levels, and ectopic expression of CDK5RAP3 was found to repress the transcription of p14(ARF. Using chromatin immunoprecipitation assay, we demonstrated that CDK5RAP3 bound to p14(ARF promoter in vivo. Furthermore, knockdown of p14(ARF in CDK5RAP3 stable knockdown HCC cells reversed the suppression of HCC cell invasiveness mediated by knockdown of CDK5RAP3. Taken together, our findings provide the new evidence that overexpression of CDK5RAP3 promotes HCC metastasis via downregulation of p14(ARF.

  9. Delocalization and destabilization of the Arf tumor suppressor by the leukemia-associated NPM mutant.

    Science.gov (United States)

    Colombo, Emanuela; Martinelli, Paola; Zamponi, Raffaella; Shing, Danielle C; Bonetti, Paola; Luzi, Lucilla; Volorio, Sara; Bernard, Loris; Pruneri, Giancarlo; Alcalay, Myriam; Pelicci, Pier Giuseppe

    2006-03-15

    One third of acute myeloid leukemias (AMLs) are characterized by the aberrant cytoplasmic localization of nucleophosmin (NPM) due to mutations within its putative nucleolar localization signal. NPM mutations are mutually exclusive with major AML-associated chromosome rearrangements and are frequently associated with a normal karyotype, suggesting that they are critical during leukemogenesis. The underlying molecular mechanisms are, however, unknown. NPM is a nucleocytoplasmic shuttling protein that has been implicated in several cellular processes, including ribosome biogenesis, centrosome duplication, cell cycle progression, and stress response. It has been recently shown that NPM is required for the stabilization and proper nucleolar localization of the tumor suppressor p19(Arf). We report here that the AML-associated NPM mutant localizes mainly in the cytoplasm due to an alteration of its nucleus-cytoplasmic shuttling equilibrium, forms a direct complex with p19(Arf), but is unable to protect it from degradation. Consequently, cells or leukemic blasts expressing the NPM mutant have low levels of cytoplasmic Arf. Furthermore, we show that expression of the NPM mutant reduces the ability of Arf to initiate a p53 response and to induce cell cycle arrest. Inactivation of p19(Arf), a key regulator of the p53-dependent cellular response to oncogene expression, might therefore contribute to leukemogenesis in AMLs with mutated NPM.

  10. 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.

  11. 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.

  12. CDK5RAP3 is a novel repressor of p14ARF in hepatocellular carcinoma cells

    OpenAIRE

    Grace Wing-Yan Mak; Wai-Lung Lai; Yuan Zhou; Mingtao Li; Irene Oi-Lin Ng; Yick-Pang Ching

    2012-01-01

    CDK5 regulatory subunit associated protein 3 (CDK5RAP3) is a novel activator of PAK4 and processes important pro-metastatic function in hepatocarcinogenesis. However, it remains unclear if there are other mechanisms by which CDK5RAP3 promotes HCC metastasis. Here, we showed that in CDK5RAP3 stable knockdown SMMC-7721 HCC cells, p14(ARF) tumor suppressor was upregulated at protein and mRNA levels, and ectopic expression of CDK5RAP3 was found to repress the transcription of p14(ARF). Using chro...

  13. Mutual exclusivity analysis of genetic and epigenetic drivers in melanoma identifies a link between p14ARF and retinoic acid receptor β signaling

    DEFF Research Database (Denmark)

    Dahl, Christina; Christensen, Claus; Jonsson, Goran

    2013-01-01

    affecting p14ARF (P melanocytes, and that the steady-state levels of p14ARF in these cells...... are regulated via RARβ. Furthermore, we show that the ability of ATRA to induce senescence is reduced in p14ARF-depleted melanocytes, and we provide proof-of-concept that ATRA can induce irreversible growth arrest in melanoma cells with an intact RARβ-p14ARF axis, independent of p16INK4A and p53 status...

  14. GTPase activity and neuronal toxicity of Parkinson's disease-associated LRRK2 is regulated by ArfGAP1.

    Directory of Open Access Journals (Sweden)

    Klodjan Stafa

    Full Text Available Mutations in the leucine-rich repeat kinase 2 (LRRK2 gene are the most common cause of autosomal dominant familial Parkinson's disease (PD and also contribute to idiopathic PD. LRRK2 encodes a large multi-domain protein with GTPase and kinase activity. Initial data indicates that an intact functional GTPase domain is critically required for LRRK2 kinase activity. PD-associated mutations in LRRK2, including the most common G2019S variant, have variable effects on enzymatic activity but commonly alter neuronal process morphology. The mechanisms underlying the intrinsic and extrinsic regulation of LRRK2 GTPase and kinase activity, and the pathogenic effects of familial mutations, are incompletely understood. Here, we identify a novel functional interaction between LRRK2 and ADP-ribosylation factor GTPase-activating protein 1 (ArfGAP1. LRRK2 and ArfGAP1 interact in vitro in mammalian cells and in vivo in brain, and co-localize in the cytoplasm and at Golgi membranes. PD-associated and functional mutations that alter the GTPase activity of LRRK2 modulate the interaction with ArfGAP1. The GTP hydrolysis activity of LRRK2 is markedly enhanced by ArfGAP1 supporting a role for ArfGAP1 as a GTPase-activating protein for LRRK2. Unexpectedly, ArfGAP1 promotes the kinase activity of LRRK2 suggesting a potential role for GTP hydrolysis in kinase activation. Furthermore, LRRK2 robustly and directly phosphorylates ArfGAP1 in vitro. Silencing of ArfGAP1 expression in primary cortical neurons rescues the neurite shortening phenotype induced by G2019S LRRK2 overexpression, whereas the co-expression of ArfGAP1 and LRRK2 synergistically promotes neurite shortening in a manner dependent upon LRRK2 GTPase activity. Neurite shortening induced by ArfGAP1 overexpression is also attenuated by silencing of LRRK2. Our data reveal a novel role for ArfGAP1 in regulating the GTPase activity and neuronal toxicity of LRRK2; reciprocally, LRRK2 phosphorylates ArfGAP1 and is

  15. 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.

  16. Molecular cloning and characterization of an ADP-ribosylation factor 6 gene (ptARF6) from Pisolithus tinctorius.

    Science.gov (United States)

    Wang, Liling; Li, Haibo; Zhou, Yifeng; Qin, Yuchuan; Wang, Yanbin; Liu, Bentong; Qian, Hua

    2016-05-01

    ADP-ribosylation factor 6 (ARF6) is an evolutionarily conserved molecule that has an essential function in intracellular trafficking and organelle structure. To better understand its role during presymbiosis between plant roots and compatible filamentous fungi, the full-length cDNA sequence of ARF6 from Pisolithus tinctorius was cloned and a variety of bioinformatics analyses performed. The full-length sequence was 849 bp long and contained a 549 bp open reading frame encoding a protein of 182 amino acids. A phylogenetic analysis showed that ptARF6 was the ortholog of the ADP ribosylation factor 6/GTPase SAR1 gene from the white-rot basidiomycete Trametes versicolor. A domain architecture analysis of the ARF6 protein revealed a repeat region, which is a common feature of ARF6 in other species. Recombinant ARF6 protein was expressed with an N-terminal 6×His tag and purified using Ni(2+)-NTA affinity chromatography. The molecular mass of the recombinant protein was estimated by SDS-PAGE to be 25 kDa. The recombinant ARF6 protein bound strongly to 18:1 and 18:2 phosphatidic acids. Thus, ARF6 may participate in the signaling pathways involved in membrane phospholipid composition. The intracellular distribution of ptADP6 in HEK239T cells also indicates that ptADP6 may function not only in plasma membrane events but also in endosomal membranes events. Real-time quantitative PCR revealed that the differential expression of ptARF6 was associated with the presymbiotic stage. ptARF6 may be induced by presymbiosis during the regulation of mycorrhizal formation.

  17. 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.

  18. Rab, Arf, and Arl-Regulated Membrane Traffic in Cortical Neuron Migration.

    Science.gov (United States)

    Tang, Bor Luen

    2016-07-01

    The migration of projection neurons from its birthplace in the subventricular zone to their final destination in the cortical plate is a complex process that requires a series of highly coordinated cellular events. Amongst the key factors involved in the processes are modulators of cytoskeletal dynamics, as well as cellular membrane traffic. Members of the small GTPases family responsible for the latter process, the Rabs and Arfs, have been recently implicated in cortical neuron migration. Rab5 and Rab11, which are key modulators of endocytosis and endocytic recycling respectively, ensure proper surface expression and distribution of N-cadherin, a key adhesion protein that tethers migrating neurons to the radial glia fiber tracts during pia-directed migration. Rab7, which is associated with lysosomal biogenesis and function, is important for the final step of terminal translocation when N-cadherin is downregulated by lysosomal degradation. Arf6 activity, which is known to be important in neuronal processes outgrowth, may negatively impact the multipolar-bipolar transition of cortical neurons undergoing radial migration, but the downstream effector of Arf6 in this regard is not yet known. In addition to the above, members of the Arl family which have been recently shown to be important in radial glia scaffold formation, would also be important for cortical neuron migration. In this short review, we discuss recent advances in our understanding of the importance of membrane traffic regulated by the Rab, Arf, and Arl family members in cortical neuron migration.

  19. Nucleophosmin is required for DNA integrity and p19Arf protein stability

    DEFF Research Database (Denmark)

    Colombo, Emanuela; Bonetti, Paola; Lazzerini Denchi, Eros

    2005-01-01

    Nucleophosmin (NPM) is a nucleolar phosphoprotein that binds the tumor suppressors p53 and p19(Arf) and is thought to be indispensable for ribogenesis, cell proliferation, and survival after DNA damage. The NPM gene is the most frequent target of genetic alterations in leukemias and lymphomas, th...

  20. Properties of human dentin surface after ArF excimer laser irradiation.

    Science.gov (United States)

    Ishida, Tomohiro; Tonami, Ken-ichi; Araki, Kouji; Kurosaki, Norimasa

    2008-03-01

    Recently, improvement of the properties of dentin surface using dental lasers to increase bonding strength has been anticipated in the field of adhesive dentistry. The objective of this study was to investigate changes in the surface properties of human dentin after ArF excimer laser irradiation at different irradiation times, pulse repetition rates and energy densities. The SEM images of the irradiated surfaces were observed, and the contact angle and the roughness of the irradiated surface were measured. As a result, SEM demonstrated that the dentin surface became irregular following ArF excimer laser irradiation. When the energy density increased, the irregularity became more minute and dentinal tubules were more easily identified. By contrast, such changes were not observed when the irradiation time and pulse repetition rate were changed. Moreover, as energy densities increased, the contact angle tended to decrease and the surface roughness tended to increase. These results suggested that the area of the irradiated surface and wettability increased after irradiation with the ArF excimer laser. Consequently, irradiation with ArF excimer lasers could improve the surface properties and be potentially useful for adhesive dentistry.

  1. The clathrin adaptor AP-1 complex and Arf1 regulate planar cell polarity in vivo.

    Science.gov (United States)

    Carvajal-Gonzalez, Jose Maria; Balmer, Sophie; Mendoza, Meg; Dussert, Aurore; Collu, Giovanna; Roman, Angel-Carlos; Weber, Ursula; Ciruna, Brian; Mlodzik, Marek

    2015-04-07

    A key step in generating planar cell polarity (PCP) is the formation of restricted junctional domains containing Frizzled/Dishevelled/Diego (Fz/Dsh/Dgo) or Van Gogh/Prickle (Vang/Pk) complexes within the same cell, stabilized via Flamingo (Fmi) across cell membranes. Although models have been proposed for how these complexes acquire and maintain their polarized localization, the machinery involved in moving core PCP proteins around cells remains unknown. We describe the AP-1 adaptor complex and Arf1 as major regulators of PCP protein trafficking in vivo. AP-1 and Arf1 disruption affects the accumulation of Fz/Fmi and Vang/Fmi complexes in the proximo-distal axis, producing severe PCP phenotypes. Using novel tools, we demonstrate a direct and specific Arf1 involvement in Fz trafficking in vivo. Moreover, we uncover a conserved Arf1 PCP function in vertebrates. Our data support a model whereby the trafficking machinery plays an important part during PCP establishment, promoting formation of polarized PCP-core complexes in vivo.

  2. Which Way In? The RalF Arf-GEF Orchestrates Rickettsia Host Cell Invasion.

    Directory of Open Access Journals (Sweden)

    Kristen E Rennoll-Bankert

    2015-08-01

    Full Text Available Bacterial Sec7-domain-containing proteins (RalF are known only from species of Legionella and Rickettsia, which have facultative and obligate intracellular lifestyles, respectively. L. pneumophila RalF, a type IV secretion system (T4SS effector, is a guanine nucleotide exchange factor (GEF of ADP-ribosylation factors (Arfs, activating and recruiting host Arf1 to the Legionella-containing vacuole. In contrast, previous in vitro studies showed R. prowazekii (Typhus Group RalF is a functional Arf-GEF that localizes to the host plasma membrane and interacts with the actin cytoskeleton via a unique C-terminal domain. As RalF is differentially encoded across Rickettsia species (e.g., pseudogenized in all Spotted Fever Group species, it may function in lineage-specific biology and pathogenicity. Herein, we demonstrate RalF of R. typhi (Typhus Group interacts with the Rickettsia T4SS coupling protein (RvhD4 via its proximal C-terminal sequence. RalF is expressed early during infection, with its inactivation via antibody blocking significantly reducing R. typhi host cell invasion. For R. typhi and R. felis (Transitional Group, RalF ectopic expression revealed subcellular localization with the host plasma membrane and actin cytoskeleton. Remarkably, R. bellii (Ancestral Group RalF showed perinuclear localization reminiscent of ectopically expressed Legionella RalF, for which it shares several structural features. For R. typhi, RalF co-localization with Arf6 and PI(4,5P2 at entry foci on the host plasma membrane was determined to be critical for invasion. Thus, we propose recruitment of PI(4,5P2 at entry foci, mediated by RalF activation of Arf6, initiates actin remodeling and ultimately facilitates bacterial invasion. Collectively, our characterization of RalF as an invasin suggests that, despite carrying a similar Arf-GEF unknown from other bacteria, different intracellular lifestyles across Rickettsia and Legionella species have driven divergent roles

  3. Which Way In? The RalF Arf-GEF Orchestrates Rickettsia Host Cell Invasion.

    Science.gov (United States)

    Rennoll-Bankert, Kristen E; Rahman, M Sayeedur; Gillespie, Joseph J; Guillotte, Mark L; Kaur, Simran J; Lehman, Stephanie S; Beier-Sexton, Magda; Azad, Abdu F

    2015-08-01

    Bacterial Sec7-domain-containing proteins (RalF) are known only from species of Legionella and Rickettsia, which have facultative and obligate intracellular lifestyles, respectively. L. pneumophila RalF, a type IV secretion system (T4SS) effector, is a guanine nucleotide exchange factor (GEF) of ADP-ribosylation factors (Arfs), activating and recruiting host Arf1 to the Legionella-containing vacuole. In contrast, previous in vitro studies showed R. prowazekii (Typhus Group) RalF is a functional Arf-GEF that localizes to the host plasma membrane and interacts with the actin cytoskeleton via a unique C-terminal domain. As RalF is differentially encoded across Rickettsia species (e.g., pseudogenized in all Spotted Fever Group species), it may function in lineage-specific biology and pathogenicity. Herein, we demonstrate RalF of R. typhi (Typhus Group) interacts with the Rickettsia T4SS coupling protein (RvhD4) via its proximal C-terminal sequence. RalF is expressed early during infection, with its inactivation via antibody blocking significantly reducing R. typhi host cell invasion. For R. typhi and R. felis (Transitional Group), RalF ectopic expression revealed subcellular localization with the host plasma membrane and actin cytoskeleton. Remarkably, R. bellii (Ancestral Group) RalF showed perinuclear localization reminiscent of ectopically expressed Legionella RalF, for which it shares several structural features. For R. typhi, RalF co-localization with Arf6 and PI(4,5)P2 at entry foci on the host plasma membrane was determined to be critical for invasion. Thus, we propose recruitment of PI(4,5)P2 at entry foci, mediated by RalF activation of Arf6, initiates actin remodeling and ultimately facilitates bacterial invasion. Collectively, our characterization of RalF as an invasin suggests that, despite carrying a similar Arf-GEF unknown from other bacteria, different intracellular lifestyles across Rickettsia and Legionella species have driven divergent roles for Ral

  4. Repression of ARF10 by microRNA160 plays an important role in the mediation of leaf water loss.

    Science.gov (United States)

    Liu, Xin; Dong, Xiufen; Liu, Zihan; Shi, Zihang; Jiang, Yun; Qi, Mingfang; Xu, Tao; Li, Tianlai

    2016-10-01

    Solanum lycopersicum auxin response factor 10 (SlARF10) is post-transcriptionally regulated by Sl-miR160. Overexpression of a Sl-miR160-resistant SlARF10 (mSlARF10) resulted in narrower leaflet blades with larger stomata but lower densities. 35S:mSlARF10-6 plants with narrower excised leaves had greater water loss, which was in contrast to the wild type (WT). Further analysis revealed that the actual water loss was not consistent with the calculated stomatal water loss in 35S:mSlARF10-6 and the WT under the dehydration treatment, indicating that there is a difference in hydraulic conductance. Pretreatment with abscisic acid (ABA) and HgCl2 confirmed higher hydraulic conductance in 35S:mSlARF10, which is related to the larger stomatal size and higher activity of aquaporins (AQPs). Under ABA treatment, 35S:mSlARF10-6 showed greater sensitivity, and the stomata closed rapidly. Screening by RNA sequencing revealed that five AQP-related genes, fourteen ABA biosynthesis/signal genes and three stomatal development genes were significantly altered in 35S:mSlARF10-6 plants, and this result was verified by qRT-PCR. The promoter analysis showed that upregulated AQPs contain AuxRE and ABRE, implying that these elements may be responsible for the high expression levels of AQPs in 35S:mSlARF10-6. The three most upregulated AQPs (SlTIP1-1-like, SlPIP2;4 and SlNIP-type-like) were chosen to confirm AuxRE and ABRE function. Promoters transient expression demonstrated that the SlPIP2;4 and SlNIP-type-like AuxREs and SlPIP2;4 and SlTIP1-1-like ABREs could significantly enhance the expression of the GUS reporter in 35S:mSlARF10-6, confirming that AuxRE and ABRE may be the main factors inducing the expression of AQPs. Additionally, two upregulated transcription factors in 35S:mSlARF10-6, SlARF10 and SlABI5-like were shown to directly bind to those elements in an electromobility shift assay and a yeast one-hybrid assay. Furthermore, transient expression of down-regulated ARF10 or up

  5. Variation in Efficacy of Isolates of the Fungus ARF Against the Soybean Cyst Nematode Heterodera glycines.

    Science.gov (United States)

    Timper, P; Riggs, R D

    1998-12-01

    An unnamed fungus, designated ARF, that parasitizes eggs and sedentary stages of cyst nematodes is a potential biological control agent of Heterodera glycines. The objectives of this study were to determine whether ARF isolates differ in their ability to suppress nematode numbers in soil and to compare the efficacy of ARF in heat-treated and native soil. The effectiveness of 11 ARF isolates was compared by introducing homogenized mycelium into heat-treated soil. Soybean seedlings were transplanted into pots containing fungus-infested soil and inoculated with H. glycines. After 30 or 60 days, the number of nematodes and the percentage of parasitized eggs were determined. Three isolates (907, 908, and TN14), which were previously reported to be weak egg parasites in vitro, consistently suppressed nematode numbers by 50% to 100%. Of the isolates previously reported to be aggressive egg parasites, four (903, BG2, MS3, and TN12) reduced nematode numbers by 56% to 69% in at least one experimental trial, but the other four had no effect on nematode numbers. When the efficacy of isolate TN14 was tested in heat-treated and native soil, nematode suppression was greater in the heat-treated soil in only one of two trials. In both soil treatments, nematode numbers were reduced by more than 60%. We conclude that virulence toward nematode eggs in vitro is a poor indicator of effectiveness of an ARF isolate in soil, and that the presence of soil microbes may reduce, but does not completely inhibit, activity of isolate TN14.

  6. Activation-Inactivation Cycling of Rab35 and ARF6 Is Required for Phagocytosis of Zymosan in RAW264 Macrophages

    Directory of Open Access Journals (Sweden)

    Youhei Egami

    2015-01-01

    Full Text Available Phagocytosis of zymosan by phagocytes is a widely used model of microbial recognition by the innate immune system. Live-cell imaging showed that fluorescent protein-fused Rab35 accumulated in the membranes of phagocytic cups and then dissociated from the membranes of newly formed phagosomes. By our novel pull-down assay for Rab35 activity, we found that Rab35 is deactivated immediately after zymosan internalization into the cells. Phagosome formation was inhibited in cells expressing the GDP- or GTP-locked Rab35 mutant. Moreover, the simultaneous expression of ACAP2—a Rab35 effector protein—with GTP-locked Rab35 or the expression of plasma membrane-targeted ACAP2 showed a marked inhibitory effect on phagocytosis through ARF6 inactivation by the GAP activity of ACAP2. ARF6, a substrate for ACAP2, was also localized on the phagocytic cups and dissociated from the membranes of internalized phagosomes. In support of the microscopic observations, ARF6-GTP pull-down experiments showed that ARF6 is transiently activated during phagosome formation. Furthermore, the expression of GDP- or GTP-locked ARF6 mutants also suppresses the uptake of zymosan. These data suggest that the activation-inactivation cycles of Rab35 and ARF6 are required for the uptake of zymosan and that ACAP2 is an important component that links Rab35/ARF6 signaling during phagocytosis of zymosan.

  7. 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.

  8. Polycomb Mediated Epigenetic Silencing and Replication Timing at the INK4a/ARF Locus during Senescence

    Science.gov (United States)

    Verthuy, Christophe; Chasson, Lionel; Serrano, Manuel; Djabali, Malek

    2009-01-01

    Background The INK4/ARF locus encodes three tumor suppressor genes (p15Ink4b, Arf and p16Ink4a) and is frequently inactivated in a large number of human cancers. Mechanisms regulating INK4/ARF expression are not fully characterized. Principal Findings Here we show that in young proliferating embryonic fibroblasts (MEFs) the Polycomb Repressive Complex 2 (PRC2) member EZH2 together with PRC1 members BMI1 and M33 are strongly expressed and localized at the INK4/ARF regulatory domain (RD) identified as a DNA replication origin. When cells enter senescence the binding to RD of both PRC1 and PRC2 complexes is lost leading to a decreased level of histone H3K27 trimethylation (H3K27me3). This loss is accompanied with an increased expression of the histone demethylase Jmjd3 and with the recruitment of the MLL1 protein, and correlates with the expression of the Ink4a/Arf genes. Moreover, we show that the Polycomb protein BMI1 interacts with CDC6, an essential regulator of DNA replication in eukaryotic cells. Finally, we demonstrate that Polycomb proteins and associated epigenetic marks are crucial for the control of the replication timing of the INK4a/ARF locus during senescence. Conclusions We identified the replication licencing factor CDC6 as a new partner of the Polycomb group member BMI1. Our results suggest that in young cells Polycomb proteins are recruited to the INK4/ARF locus through CDC6 and the resulting silent locus is replicated during late S-phase. Upon senescence, Jmjd3 is overexpressed and the MLL1 protein is recruited to the locus provoking the dissociation of Polycomb from the INK4/ARF locus, its transcriptional activation and its replication during early S-phase. Together, these results provide a unified model that integrates replication, transcription and epigenetics at the INK4/ARF locus. PMID:19462008

  9. Polycomb mediated epigenetic silencing and replication timing at the INK4a/ARF locus during senescence.

    Directory of Open Access Journals (Sweden)

    Hanane Agherbi

    Full Text Available BACKGROUND: The INK4/ARF locus encodes three tumor suppressor genes (p15(Ink4b, Arf and p16(Ink4a and is frequently inactivated in a large number of human cancers. Mechanisms regulating INK4/ARF expression are not fully characterized. PRINCIPAL FINDINGS: Here we show that in young proliferating embryonic fibroblasts (MEFs the Polycomb Repressive Complex 2 (PRC2 member EZH2 together with PRC1 members BMI1 and M33 are strongly expressed and localized at the INK4/ARF regulatory domain (RD identified as a DNA replication origin. When cells enter senescence the binding to RD of both PRC1 and PRC2 complexes is lost leading to a decreased level of histone H3K27 trimethylation (H3K27me3. This loss is accompanied with an increased expression of the histone demethylase Jmjd3 and with the recruitment of the MLL1 protein, and correlates with the expression of the Ink4a/Arf genes. Moreover, we show that the Polycomb protein BMI1 interacts with CDC6, an essential regulator of DNA replication in eukaryotic cells. Finally, we demonstrate that Polycomb proteins and associated epigenetic marks are crucial for the control of the replication timing of the INK4a/ARF locus during senescence. CONCLUSIONS: We identified the replication licencing factor CDC6 as a new partner of the Polycomb group member BMI1. Our results suggest that in young cells Polycomb proteins are recruited to the INK4/ARF locus through CDC6 and the resulting silent locus is replicated during late S-phase. Upon senescence, Jmjd3 is overexpressed and the MLL1 protein is recruited to the locus provoking the dissociation of Polycomb from the INK4/ARF locus, its transcriptional activation and its replication during early S-phase. Together, these results provide a unified model that integrates replication, transcription and epigenetics at the INK4/ARF locus.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

    Energy Technology Data Exchange (ETDEWEB)

    Kurayoshi, Kenta [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan); Ozono, Eiko [Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary, University of London, John Vane Science Centre, Charterhouse Square, London EC1M 6BQ (United Kingdom); Iwanaga, Ritsuko; Bradford, Andrew P. [Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045 (United States); Komori, Hideyuki [Center for Stem Cell Biology, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109 (United States); Ohtani, Kiyoshi, E-mail: btm88939@kwansei.ac.jp [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)

    2014-07-18

    Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

  15. 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...

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. Structure of an ADP-ribosylation factor, ARF1, from Entamoeba histolytica bound to Mg(2+)-GDP.

    Science.gov (United States)

    Serbzhinskiy, Dmitry A; Clifton, Matthew C; Sankaran, Banumathi; Staker, Bart L; Edwards, Thomas E; Myler, Peter J

    2015-05-01

    Entamoeba histolytica is the etiological agent of amebiasis, a diarrheal disease which causes amoebic liver abscesses and amoebic colitis. Approximately 50 million people are infected worldwide with E. histolytica. With only 10% of infected people developing symptomatic amebiasis, there are still an estimated 100,000 deaths each year. Because of the emergence of resistant strains of the parasite, it is necessary to find a treatment which would be a proper response to this challenge. ADP-ribosylation factor (ARF) is a member of the ARF family of GTP-binding proteins. These proteins are ubiquitous in eukaryotic cells; they generally associate with cell membranes and regulate vesicular traffic and intracellular signalling. The crystal structure of ARF1 from E. histolytica has been determined bound to magnesium and GDP at 1.8 Å resolution. Comparison with other structures of eukaryotic ARF proteins shows a highly conserved structure and supports the interswitch toggle mechanism of communicating the conformational state to partner proteins.

  1. The identification and characterization of specific ARF-Aux/IAA regulatory modules in plant growth and development.

    Science.gov (United States)

    Krogan, Naden T; Berleth, Thomas

    2015-01-01

    The current model of auxin-inducible transcription describes numerous regulatory interactions between AUXIN RESPONSE FACTORs (ARFs) and Aux/IAAs. However, specific relationships between individual members of these families in planta remain largely uncharacterized. Using a systems biology approach, the entire suite of Aux/IAA genes directly regulated by the developmentally pivotal ARF MONOPTEROS (MP) was recently determined for multiple Arabidopsis tissue types. This study showed that MP directly targets distinct subclades of Aux/IAAs, revealing potential regulatory modules of redundantly acting Aux/IAAs involved in MP-dependent processes. Further, functional analyses indicated that the protein products of these targeted Aux/IAAs negatively feedback on MP. Thus, comprehensive identification of Aux/IAAs targeted by individual ARFs will generate biologically meaningful networks of ARF-Aux/IAA regulatory modules controlling distinct plant pathways.

  2. Cahit Arf: Exploring his scientific influence using social network analysis, author co-citation maps and single publication h index1

    Directory of Open Access Journals (Sweden)

    Yasar Tonta

    2013-01-01

    Full Text Available Cahit Arf (1910-1997, a famous Turkish scientist whose picture is depicted in one of the Turkish banknotes, is a well-known figure in mathematics with his discoveries named after him (e.g., Arf invariant, Arf rings, the Hasse-Arf theorem. Although Arf may not be considered as a prolific scientist in terms of number of papers (he authored a total of 23 papers, his influence on mathematics and related disciplines was profound. As he was active before, during, and after World War II, Arf′s contributions are not properly listed in citation indexes, and thus did not generate many citations even though several papers with "Arf" in their titles appeared in literature. This paper traces influence of Arf in scientific world using citation analysis techniques first. It reviews scientific impact of Arf by analyzing both; the papers authored by Arf and papers whose titles or keywords containing various combinations of "Arf invariant," "Arf rings," and so on. The paper then goes on to study Arf′s contributions using social network analysis (SNA and author co-citation analysis (ACA techniques. CiteSpace and pennant diagrams are used to explore scientific impact of Arf by mapping his cited references derived from Thomson Reuters′ Web of Science (WoS database. The direct and indirect influences of Arf′s highly cited paper on Arf invariant are assessed through ACA and single publication h index, respectively. The paper ends with a discussion of whether data analysis techniques used in this study can be useful to study scientific impact of researchers retrospectively.

  3. The Qb-SNARE Memb11 interacts specifically with Arf1 in the Golgi apparatus of Arabidopsis thaliana.

    Science.gov (United States)

    Marais, Claireline; Wattelet-Boyer, Valérie; Bouyssou, Guillaume; Hocquellet, Agnès; Dupuy, Jean-William; Batailler, Brigitte; Brocard, Lysiane; Boutté, Yohann; Maneta-Peyret, Lilly; Moreau, Patrick

    2015-11-01

    The SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins are critical for the function of the secretory pathway. The SNARE Memb11 is involved in membrane trafficking at the ER-Golgi interface. The aim of the work was to decipher molecular mechanisms acting in Memb11-mediated ER-Golgi traffic. In mammalian cells, the orthologue of Memb11 (membrin) is potentially involved in the recruitment of the GTPase Arf1 at the Golgi membrane. However molecular mechanisms associated to Memb11 remain unknown in plants. Memb11 was detected mainly at the cis-Golgi and co-immunoprecipitated with Arf1, suggesting that Arf1 may interact with Memb11. This interaction of Memb11 with Arf1 at the Golgi was confirmed by in vivo BiFC (Bimolecular Fluorescence Complementation) experiments. This interaction was found to be specific to Memb11 as compared to either Memb12 or Sec22. Using a structural bioinformatic approach, several sequences in the N-ter part of Memb11 were hypothesized to be critical for this interaction and were tested by BiFC on corresponding mutants. Finally, by using both in vitro and in vivo approaches, we determined that only the GDP-bound form of Arf1 interacts with Memb11. Together, our results indicate that Memb11 interacts with the GDP-bound form of Arf1 in the Golgi apparatus.

  4. Over-expression of mango (Mangifera indica L.) MiARF2 inhibits root and hypocotyl growth of Arabidopsis.

    Science.gov (United States)

    Wu, Bei; Li, Yun-He; Wu, Jian-Yong; Chen, Qi-Zhu; Huang, Xia; Chen, Yun-Feng; Huang, Xue-Lin

    2011-06-01

    An auxin response factor 2 gene, MiARF2, was cloned in our previous study [1] from the cotyledon section of mango (Mangifera indica L. cv. Zihua) during adventitious root formation, which shares an 84% amino acid sequence similarity to Arabidopsis ARF2. This study was to examine the effects of over-expression of the full-length MiARF2 open reading frame on the root and hypocotyl growth in Arabidopsis. Phenotype analysis showed that the T(3) transgenic lines had about 20-30% reduction in the length of hypocotyls and roots of the seedlings in comparison with the wild-type. The transcription levels of ANT and ARGOS genes which play a role in controlling organ size and cell proliferation in the transgenic seedlings also decreased. Therefore, the inhibited root and hypocotyl growth in the transgenic seedlings may be associated with the down-regulated transcription of ANT and ARGOS by the over-expression of MiARF2. This study also suggests that although MiARF2 only has a single DNA-binding domain (DBD), it can function as other ARF-like proteins containing complete DBD, middle region (MR) and carboxy-terminal dimerization domain (CTD).

  5. [The structural characteristics, alternative splicing and genetic experession analysis of ADP-ribosylation-factor 1 (arf1) in cotton].

    Science.gov (United States)

    Ren, Mao-Zhi; Chen, Quan-Jia; Zhang, Rui; Guo, San-Dui

    2004-08-01

    The full-length cDNA,DNA and promoter of ADP-ribosylation-factor 1 (arf1) was isolated from Gossypium hirsutum Y18 by means of isocaudarner inverse PCR (II-PCR) and rapid isolating cDNA 5' unknown sequence and promoter (RICUP) established in our lab. Results indicated that the gene is 4 360 bp in size, including seven exons and six introns. Interestingly, alterative splicing occurs at intron I. Differential processing of intron 1 yields three different transcripts with 1 026 bp, 1103 bp and 1 544 bp in sizes, respectively. Arf1 encodes 181 amino acids. Sequence analysis indicated that sequence upstream transcription initiation site of arf1 includes typical initiator, TATA box, CCAAT box, GC box and several forward and reverse repeat sequences. And typical promoter structures, such as AT-rich sequence and palindrome structure have been detected in the sequence downstream transcription initiation site. Southern blot analysis indicated that the gene has two copies in the genome of cotton. Northern blot confirmed the predominate expression of arf1 in reproductive organs of cotton, including bud, flower, fiber and boll. Also, the feature and character of arf1 and its promoter have been studied. This study will lay foundation for the other research on function of arf1 in the development of reproductive organs in cotton.

  6. Functional interactions between Lmo2, the Arf tumor suppressor, and Notch1 in murine T-cell malignancies.

    Science.gov (United States)

    Treanor, Louise M; Volanakis, Emmanuel J; Zhou, Sheng; Lu, Taihe; Sherr, Charles J; Sorrentino, Brian P

    2011-05-19

    LMO2 is a target of chromosomal translocations in T-cell tumors and was activated by retroviral vector insertions in T-cell tumors from X-SCID patients in gene therapy trials. To better understand the cooperating genetic events in LMO2-associated T-cell acute lymphoblastic leukemia (T-ALL), we investigated the roles of Arf tumor suppressor loss and Notch activation in murine models of transplantation. Lmo2 overexpression enhanced the expansion of primitive DN2 thymocytes, eventually facilitating the stochastic induction of clonal CD4(+)/CD8(+) malignancies. Inactivation of the Arf tumor suppressor further increased the self-renewal capacity of the primitive, preleukemic thymocyte pool and accelerated the development of aggressive, Lmo2-induced T-cell lympholeukemias. Notch mutations were frequently detected in these Lmo2-induced tumors. The Arf promoter was not directly engaged by Lmo2 or mutant Notch, and use of a mouse model in which activation of a mutant Notch allele depends on previous engagement of the Arf promoter revealed that Notch activation could occur as a subsequent event in T-cell tumorigenesis. Therefore, Lmo2 cooperates with Arf loss to enhance self-renewal in primitive thymocytes. Notch mutation and Arf inactivation appear to independently cooperate in no requisite order with Lmo2 overexpression in inducing T-ALL, and all 3 events remained insufficient to guarantee immediate tumor development.

  7. A presynaptic role for the ADP ribosylation factor (ARF)-specific GDP/GTP exchange factor msec7-1.

    Science.gov (United States)

    Ashery, U; Koch, H; Scheuss, V; Brose, N; Rettig, J

    1999-02-01

    ADP ribosylation factors (ARFs) represent a family of small monomeric G proteins that switch from an inactive, GDP-bound state to an active, GTP-bound state. One member of this family, ARF6, translocates on activation from intracellular compartments to the plasma membrane and has been implicated in regulated exocytosis in neuroendocrine cells. Because GDP release in vivo is rather slow, ARF activation is facilitated by specific guanine nucleotide exchange factors like cytohesin-1 or ARNO. Here we show that msec7-1, a rat homologue of cytohesin-1, translocates ARF6 to the plasma membrane in living cells. Overexpression of msec7-1 leads to an increase in basal synaptic transmission at the Xenopus neuromuscular junction. msec7-1-containing synapses have a 5-fold higher frequency of spontaneous synaptic currents than control synapses. On stimulation, the amplitudes of the resulting evoked postsynaptic currents of msec7-1-overexpressing neurons are increased as well. However, further stimulation leads to a decline in amplitudes approaching the values of control synapses. This transient effect on amplitude is strongly reduced on overexpression of msec7-1E157K, a mutant incapable of translocating ARFs. Our results provide evidence that small G proteins of the ARF family and activating factors like msec7-1 play an important role in synaptic transmission, most likely by making more vesicles available for fusion at the plasma membrane.

  8. Identification of ARF and AUX/IAA gene families in Rafflesia cantleyi

    Science.gov (United States)

    Elias, Nur Atiqah Mohd; Goh, Hoe-Han; Isa, Nurulhikma Md; Wan, Kiew-Lian

    2016-11-01

    Rafflesia is a unique plant that produces the largest flowers in the world. It has a short blooming period of 6 to 7 days. Due to its rarity and limited accessibility, little is known about the growth and developmental process in the Rafflesia plant. In all plant species, auxin is the key hormone that is involved in growth and development. The auxin signal transduction involves members of the ARF transcription factor and AUX/IAA regulator families, which activate or inhibit the regulation of auxin response genes, thereby control the developmental process in plants. To gain a better understanding of molecular regulations in the Rafflesia plant development during flowering, members of the ARF and AUX/IAA gene families were identified from the transcriptome data of flower blooming stages in Rafflesia cantleyi. Based on Rafflesia unique transcripts (UTs) against the Arabidopsis TAIR database using BLASTX search, a total of nine UTs were identified as ARF transcription factors, while another seven UTs were identified as AUX/IAA regulators. These genes were found to be expressed in all three R. cantleyi flower stages i.e. days 1 (F1), 3 (F2), and 5 (F3). Gene expression analysis identified three genes that are differentially expressed in stage F1 vs. F2 i.e. IAA4 is upregulated while IAA8 and ARF3 are downregulated. These genes may be involved in the activation and/or inhibition of the auxin signal transduction pathway. Further analysis of these genes may unravel their function in the phenotypic development of the Rafflesia plant.

  9. Illuga saga Gríðarfóstra in Sweden

    DEFF Research Database (Denmark)

    Lavender, Philip Thomas

    2014-01-01

    This article looks at the intellectual history behind and scholarly preparation towards the first edition of Illuga saga Gríðarfóstra in Sweden in 1695. One of the main questions which the article tries to answer is why an edition of a saga about Danish kings and heroes would end up being produced...... in the middle of the Sweden and Denmark's fiercely competitive nation-building furore....

  10. Continuous veno-venous hemofiltration for ARF in critically Ill patients

    Directory of Open Access Journals (Sweden)

    Wadia F

    2004-01-01

    Full Text Available The mortality of critically ill patients who develop ARF in an ICU setting is extremely high (50-80%. Any mode of renal replacement therapy chosen should be able to achieve solute and water clearance while maintaining hemodynamic stability, have a positive effect on nutrition, and have low complication rates. AIM: To determine the efficacy and feasibility of Continuous Venovenous hemofiltration (CVVH in critically ill patients with ARF. Inclusion criteria: Patients with ARF requiring 2 or more inotropes to maintain systolic blood pressure >100 mm of Hg. Failed or technically impossible hemodialysis or peritoneal dialysis. Time Period: July 2002 - June 2003. MATERIALS AND METHODS: Polysulfone hemofilter 0.7m2, [Aquamax (Edwards or Multimat BL680 (Bellco.] Blood flow of 150-200 ml/minute (Travenol. Volumetrically controlled Ultrafiltration of > 2000 ml per hour (Watson Marlowe and replacement fluid infusion [(Infusomat-P post filter]. Anticoagulation: Heparin infusion or regional heparinisation. RESULTS: 22 patients included, 6 with recent abdominal surgery. 11 underwent hemodiafiltration and hemofiltration each. Severe sepsis was present in 21, and DIC in18. 5 patients were on immunosuppressive therapy. The time from ICU admission to the start of CVVH was 114 + 88.08 hours. The duration of CVVH was 35.93 + 20.91 hours, (range 11 to 84 hours. The mean hourly ultrafiltration of 93.72 + 65.57 ml and total ultrafiltration of 3955.55 + 4132 ml was tolerated by all patients without limiting hypotension. The APACHE II scores had significantly worsened between admission (22.5 + 6.71 to starting CVVH (36.05 + 4.08, [P<0.001]. The daily costs of CVVH were Rs. 5000 compared to Rs. 2150 for PD and Rs. 1500 for extended daily dialysis CONCLUSIONS: CVVH was effective in providing metabolic correction in ARF, in the setting of multi-organ failure. It is technically feasible even when conventional hemodialysis or peritoneal dialysis cannot be performed.

  11. Establishing epithelial glandular polarity: interlinked roles for ARF6, Rac1, and the matrix microenvironment.

    Science.gov (United States)

    Monteleon, Christine L; Sedgwick, Alanna; Hartsell, Alyssa; Dai, Michael; Whittington, Catherine; Voytik-Harbin, Sherry; D'Souza-Schorey, Crislyn

    2012-12-01

    Epithelial cysts comprise the structural units of the glandular epithelium. Although glandular inversion in epithelial tumors is thought to be a potential mechanism for the establishment of metastatic disease, little is known about the morphogenic cues and signaling pathways that govern glandular polarity and organization. Using organotypic cultures of Madin-Darby canine kidney cells in reconstituted basement membrane, we show that cellular depletion of the small GTP-binding protein ARF6 promotes the formation of inverted cysts, wherein the apical cell membrane faces the cyst exterior, and the basal domain faces the central lumen, while individual cell polarity is maintained. These cysts are also defective in interactions with laminin at the cyst-matrix interface. This inversion of glandular orientation is accompanied by Rac1 inactivation during early cystogenesis, and temporal activation of Rac1 is sufficient to recover the normal cyst phenotype. In an unnatural collagen I microenvironment, ARF6-depleted, inverted epithelial cysts exhibit some loss of cell polarity, a marked increase in Rho activation and Rac1 inactivation, and striking rearrangement of the surrounding collagen I matrix. These studies demonstrate the importance of ARF6 as a critical determinant of glandular orientation and the matrix environment in dictating structural organization of epithelial cysts.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Integrative Model of Oxidative Stress Adaptation in the Fungal Pathogen Candida albicans.

    Directory of Open Access Journals (Sweden)

    Chandrasekaran Komalapriya

    Full Text Available The major fungal pathogen of humans, Candida albicans, mounts robust responses to oxidative stress that are critical for its virulence. These responses counteract the reactive oxygen species (ROS that are generated by host immune cells in an attempt to kill the invading fungus. Knowledge of the dynamical processes that instigate C. albicans oxidative stress responses is required for a proper understanding of fungus-host interactions. Therefore, we have adopted an interdisciplinary approach to explore the dynamical responses of C. albicans to hydrogen peroxide (H2O2. Our deterministic mathematical model integrates two major oxidative stress signalling pathways (Cap1 and Hog1 pathways with the three major antioxidant systems (catalase, glutathione and thioredoxin systems and the pentose phosphate pathway, which provides reducing equivalents required for oxidative stress adaptation. The model encapsulates existing knowledge of these systems with new genomic, proteomic, transcriptomic, molecular and cellular datasets. Our integrative approach predicts the existence of alternative states for the key regulators Cap1 and Hog1, thereby suggesting novel regulatory behaviours during oxidative stress. The model reproduces both existing and new experimental observations under a variety of scenarios. Time- and dose-dependent predictions of the oxidative stress responses for both wild type and mutant cells have highlighted the different temporal contributions of the various antioxidant systems during oxidative stress adaptation, indicating that catalase plays a critical role immediately following stress imposition. This is the first model to encapsulate the dynamics of the transcriptional response alongside the redox kinetics of the major antioxidant systems during H2O2 stress in C. albicans.

  17. Integrative Model of Oxidative Stress Adaptation in the Fungal Pathogen Candida albicans.

    Science.gov (United States)

    Komalapriya, Chandrasekaran; Kaloriti, Despoina; Tillmann, Anna T; Yin, Zhikang; Herrero-de-Dios, Carmen; Jacobsen, Mette D; Belmonte, Rodrigo C; Cameron, Gary; Haynes, Ken; Grebogi, Celso; de Moura, Alessandro P S; Gow, Neil A R; Thiel, Marco; Quinn, Janet; Brown, Alistair J P; Romano, M Carmen

    2015-01-01

    The major fungal pathogen of humans, Candida albicans, mounts robust responses to oxidative stress that are critical for its virulence. These responses counteract the reactive oxygen species (ROS) that are generated by host immune cells in an attempt to kill the invading fungus. Knowledge of the dynamical processes that instigate C. albicans oxidative stress responses is required for a proper understanding of fungus-host interactions. Therefore, we have adopted an interdisciplinary approach to explore the dynamical responses of C. albicans to hydrogen peroxide (H2O2). Our deterministic mathematical model integrates two major oxidative stress signalling pathways (Cap1 and Hog1 pathways) with the three major antioxidant systems (catalase, glutathione and thioredoxin systems) and the pentose phosphate pathway, which provides reducing equivalents required for oxidative stress adaptation. The model encapsulates existing knowledge of these systems with new genomic, proteomic, transcriptomic, molecular and cellular datasets. Our integrative approach predicts the existence of alternative states for the key regulators Cap1 and Hog1, thereby suggesting novel regulatory behaviours during oxidative stress. The model reproduces both existing and new experimental observations under a variety of scenarios. Time- and dose-dependent predictions of the oxidative stress responses for both wild type and mutant cells have highlighted the different temporal contributions of the various antioxidant systems during oxidative stress adaptation, indicating that catalase plays a critical role immediately following stress imposition. This is the first model to encapsulate the dynamics of the transcriptional response alongside the redox kinetics of the major antioxidant systems during H2O2 stress in C. albicans.

  18. 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.

  19. Genome-wide identification, isolation and expression analysis of auxin response factor(ARF gene family in sweet orange (Citrus sinensis

    Directory of Open Access Journals (Sweden)

    si-bei eli

    2015-03-01

    Full Text Available Auxin response factors (ARFs are an important family of proteins in auxin-mediated response, with key roles in various physiological and biochemical processes. To date, a genome-wide overview of the ARF gene family in citrus was not available. A systematic analysis of this gene family in citrus was begun by carrying out a genome-wide search for the homologues of auxin response genes. A total of 19 non-redundant ARF genes (CiARF were identified and validated from the sweet orange genome. A comprehensive overview of the CiARF gene family was undertaken, including the gene structures, phylogeny, chromosome locations, conserved motifs, and cis-elements in promoter sequences. Furthermore, expression profiling using real-time PCR revealed many CiARF genes, albeit with different patterns depending on types of tissues and/or developmental stages. Comprehensive expression analysis of these genes was also performed under two hormone treatments using real-time PCR. Indole-3-acetic acid and N-1-napthylphthalamic acid treatment experiments revealed differential up-regulation and down-regulation, respectively, of the 19 citrus ARF genes in the callus of sweet orange. Our comprehensive analysis of ARF genes further elucidates the roles of CiARF family members in citrus growth and development.

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

    Directory of Open Access Journals (Sweden)

    Subhajit Gantait

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  3. 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

  4. Structural Insights into Arl1-Mediated Targeting of the Arf-GEF BIG1 to the trans-Golgi

    Directory of Open Access Journals (Sweden)

    Antonio Galindo

    2016-07-01

    Full Text Available The GTPase Arf1 is the major regulator of vesicle traffic at both the cis- and trans-Golgi. Arf1 is activated at the cis-Golgi by the guanine nucleotide exchange factor (GEF GBF1 and at the trans-Golgi by the related GEF BIG1 or its paralog, BIG2. The trans-Golgi-specific targeting of BIG1 and BIG2 depends on the Arf-like GTPase Arl1. We find that Arl1 binds to the dimerization and cyclophilin binding (DCB domain in BIG1 and report a crystal structure of human Arl1 bound to this domain. Residues in the DCB domain that bind Arl1 are required for BIG1 to locate to the Golgi in vivo. DCB domain-binding residues in Arl1 have a distinct conformation from those in known Arl1-effector complexes, and this plasticity allows Arl1 to interact with different effectors of unrelated structure. The findings provide structural insight into how Arf1 GEFs, and hence active Arf1, achieve their correct subcellular distribution.

  5. Interconversion of two GDP-bound conformations and their selection in an Arf-family small G protein.

    Science.gov (United States)

    Okamura, Hideyasu; Nishikiori, Masaki; Xiang, Hongyu; Ishikawa, Masayuki; Katoh, Etsuko

    2011-07-13

    ADP-ribosylation factor (Arf) and other Arf-family small G proteins participate in many cellular functions via their characteristic GTP/GDP conformational cycles, during which a nucleotide(∗)Mg(2+)-binding site communicates with a remote N-terminal helix. However, the conformational interplay between the nucleotides, the helix, the protein core, and Mg(2+) has not been fully delineated. Herein, we report a study of the dynamics of an Arf-family protein, Arl8, under various conditions by means of NMR relaxation spectroscopy. The data indicated that, when GDP is bound, the protein core, which does not include the N-terminal helix, reversibly transition between an Arf-family GDP form and another conformation that resembles the Arf-family GTP form. Additionally, we found that the N-terminal helix and Mg(2+), respectively, stabilize the aforementioned former and latter conformations in a population-shift manner. Given the dynamics of the conformational changes, we can describe the Arl8 GTP/GDP cycle in terms of an energy diagram.

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

    Science.gov (United States)

    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.

  7. Radiative processes in air excited by an ArF laser

    Science.gov (United States)

    Laufer, Gabriel; Mckenzie, Robert L.; Huo, Winifred M.

    1988-01-01

    The emission spectrum of air that is excited by an ArF laser has been investigated experimentally and theoretically to determine the conditions under which fluorescence from O2 can be used for the measurement of temperature in aerodynamic flows. In addition to the expected fluorescence from O2, the spectrum from excitation with an intense laser beam is shown to contain significant contributions from the near-resonant Raman fundamental and overtone bands, the four-photon fluorescence excitation of C produced from ambient CO2, and possibly the three-photon excitation of O(2+). The nature of the radiative interactions contributing to these additional features is described.

  8. Structure of the catalytic domain of Plasmodium falciparum ARF GTPase-activating protein (ARFGAP)

    Energy Technology Data Exchange (ETDEWEB)

    Cook, William J.; Senkovich, Olga; Chattopadhyay, Debasish (UAB)

    2012-03-26

    The crystal structure of the catalytic domain of the ADP ribosylation factor GTPase-activating protein (ARFGAP) from Plasmodium falciparum has been determined and refined to 2.4 {angstrom} resolution. Multiwavelength anomalous diffraction (MAD) data were collected utilizing the Zn{sup 2+} ion bound at the zinc-finger domain and were used to solve the structure. The overall structure of the domain is similar to those of mammalian ARFGAPs. However, several amino-acid residues in the area where GAP interacts with ARF1 differ in P. falciparum ARFGAP. Moreover, a number of residues that form the dimer interface in the crystal structure are unique in P. falciparum ARFGAP.

  9. Collateral damage-free debridement using 193nm ArF laser

    Science.gov (United States)

    Wynne, James J.; Felsenstein, Jerome M.; Trzcinski, Robert; Zupanski-Nielsen, Donna; Connors, Daniel P.

    2011-03-01

    Burn eschar and other necrotic areas of the skin and soft tissue are anhydrous compared to the underlying viable tissue. A 193 nm ArF excimer laser, emitting electromagnetic radiation at 6.4 eV at fluence exceeding the ablation threshold, will debride such necrotic areas. Because such radiation is strongly absorbed by aqueous chloride ions through the nonthermal process of electron photodetachment, debridement will cease when hydrated (with chloride ions) viable tissue is exposed, avoiding collateral damage to this tissue. Such tissue will be sterile and ready for further treatment, such as a wound dressing and/or a skin graft.

  10. Whatever Happened to Illuga saga Gríðarfóstra?

    DEFF Research Database (Denmark)

    Lavender, Philip Thomas

    Never heard of Illuga saga Gríðarfóstra? You’re not alone. Alongside the canon of world literary treasures there lies a shady world of forgotten and abandoned texts. The focus of my doctoral research has been the revindication of one such work, not simply because humanities research revels....... It is found in 37 manuscript witnesses, but also in a number of other literary and textual formats. The relationships between these various formats - a passage from Saxo Grammaticus’ Gesta Danorum, Faroese ballads, Swedish ‘Stormaktstiden’ academic interventions and post-medieval Icelandic rímur...

  11. Analysis of Arf1 GTPase-dependent membrane binding and remodeling using the exomer secretory vesicle cargo adaptor

    Science.gov (United States)

    Paczkowski, Jon E.; Fromme, J. Christopher

    2016-01-01

    Summary Protein-protein and protein-membrane interactions play a critical role in shaping biological membranes through direct physical contact with the membrane surface. This is particularly evident in many steps of membrane trafficking, in which proteins deform the membrane and induce fission to form transport carriers. The small GTPase Arf1 and related proteins have the ability to remodel membranes by insertion of an amphipathic helix into the membrane. Arf1 and the exomer cargo adaptor coordinate cargo sorting into subset of secretory vesicle carriers in the model organism Saccharomyces cerevisiae. Here, we detail the assays we used to explore the cooperative action of Arf1 and exomer to bind and remodel membranes. We expect these methods are broadly applicable to other small GTPase/effector systems where investigation of membrane binding and remodeling is of interest. PMID:27632000

  12. Arf and RhoA regulate both the cytosolic and the membrane-bound phospholipase D from human placenta

    DEFF Research Database (Denmark)

    Vinggaard, Anne Marie; Hansen, Harald S.; Provost, J.J.;

    1997-01-01

    proteins 1 µM mArf3 (2-fold) and 0.37 nM RhoA (2-fold). This is the first report to show RhoA activation of a cytosolic PLD. The activation by mArf3 was maintained after partial purification on DEAE Sepharose of the enzyme. We have previously reported the existence of a membrane-bound PLD from human...... for the inhibitory effect. Furthermore, placental membrane PLD was activated by 30 µM GTP¿S (4-fold) and by mArf3 (1 µM) and RhoA (0.37 nM) by a factor of 3 and 2, respectively. The solubilized membrane phospholipase D was partially purified to a basal specific activity of 25-37 nmol/min/mg. This preparation...

  13. Under-expression of the Auxin Response Factor Sl-ARF4 improves postharvest behavior of tomato fruits.

    Science.gov (United States)

    Sagar, Maha; Chervin, Christian; Roustant, Jean-Paul; Bouzayen, Mondher; Zouine, Mohamed

    2013-10-01

    Auxin is one of the most prominent phytohormones regulating many aspects of fleshy fruit development including fruit set, fruit size through the control of cell division and cell expansion, and fruit ripening. To shed light on the role of auxin fruit ripening, we have previously shown that Sl-ARF4 is a major player in mediating the auxin control of sugar metabolism in tomato fruit (cv MicroTom). Further extending this study, we show here that down-regulation of Sl-ARF4 in tomato alters some ripening-related fruit quality traits including enhanced fruit density at mature stage, increased firmness, prolonged shelf-life and reduced water (weight) loss at red ripe stage. These findings suggest that Sl-ARF4 plays a role in determining fruit cell wall architecture and thus providing a potential genetic marker for improving post-harvest handling and shelf life of tomato fruits.

  14. 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.

  15. 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.

  16. 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.

  17. The role of NPM, p14arf and MDM2 in precursors of bronchial squamous cell carcinoma.

    Science.gov (United States)

    Mascaux, C; Bex, F; Martin, B; Burny, A; Haller, A; Paesmans, M; Willard-Gallo, K; Ninane, V; Sculier, J-P

    2008-09-01

    Murine double minute clone 2 (MDM2), p14 alternate reading frame (p14arf), and nucleophosmin (NPM) regulate p53 activity. A total of 200 biopsies, including normal bronchial, pre-invasive and invasive tissues, were examined for changes in NPM, p14arf, MDM2 and p53 expression patterns by immunohistochemistry and immunofluorescence with confocal microscopy. NPM and p14arf displayed a diffuse nuclear staining in most normal bronchial tissue. The fraction of biopsies displaying an increased MDM2 staining or a nucleolar relocalisation of NPM increased at mild and moderate dysplasia, respectively. Two different modifications occurred in p14arf expression, i.e. its loss or its nucleolar relocalisation, both increasing at severe dysplasia and both being associated with high MDM2 expression. In addition, the nucleolar relocalisation of p14arf was associated with that of NPM. Immunofluorescence staining indicated that NPM and p14arf either co-localised in the nucleoplasm or in the nucleoli, before and as a result of severe dysplasia, respectively. MDM2 was not detected in the nucleoli. Thus, changes occur in murine double minute clone 2, p14 alternate reading frame and nucleophosmin level of expression and/or cellular distribution during early steps of lung carcinogenesis. Their relative localisation as determined by immunofluorescence, supports the hypothesis that p14 alternate reading frame nucleolar relocalisation impairs p14 alternate reading frame-murine double minute clone 2 complex formation and that nucleophosmin might sequester p14 alternate reading frame. The demonstration of this hypothesis requires further functional studies.

  18. The phosphatase of regenerating liver 3 (PRL-3) promotes cell migration through Arf-activity-dependent stimulation of integrin α5 recycling.

    Science.gov (United States)

    Krndija, Denis; Münzberg, Christin; Maass, Ulrike; Hafner, Margit; Adler, Guido; Kestler, Hans A; Seufferlein, Thomas; Oswald, Franz; von Wichert, Götz

    2012-08-15

    The formation of metastasis is one of the most critical problems in oncology. The phosphatase of regenerating liver 3 (PRL-3) is a new target in colorectal cancer, mediating metastatic behavior through a promigratory function. However, detailed explanations for this effect have remained elusive. Here we show that PRL-3 interacts with the ADP-ribosylation factor 1 (Arf1). PRL-3 colocalizes with Arf1 in an endosomal compartment and associates with transmembrane proteins such as the transferrin receptor and α5 integrins. PRL-3 interacts with Arf1 through a distinct motif and regulates activation of Arf1. PRL-3-mediated migration depends on expression and activation of Arf1 and is sensitive to treatment with Brefeldin A. We also demonstrate that PRL-3 modulates recycling of α5 integrins and that its phosphatase activity as well as Arf activation and compartmentalization with Arf1 are required for this effect. In summary our data identify a new function for PRL-3 and show that Arf1 is a new PRL-3-dependent mediator of enhanced migration of cancer cells through enhanced recycling of matrix receptors.

  19. Isolation of a Mutant of Fer1 Gene, Acting Synergistically with the ARF8 Gene to Control Development of the Anther and Filament in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Chang-En TIAN; Yu-Ping ZHOU; Shun-Zhi LIU; Kotaro YAMAMOTO

    2005-01-01

    Auxin response factors (ARFs) play a central role in plants as transcriptional factors in response to auxin. The Arabidopsis ARF8 gene is a light-inducible gene and ARF8 protein might control auxin homeostasis in a negative feed-back fashion through regulation of GH3 gene expression. In a double mutant designated infertile line including arf8-1 (a T-DNA insertion mutant of ARF8), we isolatedfertility1-1 (fer1-1), a mutant of Fer1, which acts synergistically with ARF8 to control the development of the anther and filament in Arabidopsis. Genetics analysis has demonstrated thatfer1-1 is a T-DNA insertion line,indicating that Fer1 might be cloned by inverse polymerase chain reaction (PCR) or the TAIL-PCR approach.Phenotypic identification and molecular analysis offer1-1 and the infertile line will be helpful to characterize the function of Fer1, to further study the function of ARF8, and to reveal the molecular mechanism underlying the interaction of Fer1 and ARF8 in controlling development of the anther and filament.

  20. Genotypes of Candida albicans involved in development of candidiasis and their distribution in oral cavity of non-candidiasis individuals.

    Science.gov (United States)

    Takagi, Yuki; Hattori, Hisao; Adachi, Hidesada; Takakura, Shunji; Horii, Toshinobu; Chindamporn, Ariya; Kitai, Hiroki; Tanaka, Reiko; Yaguchi, Takashi; Fukano, Hideo; Kawamoto, Fumihiko; Shimozato, Kazuo; Kanbe, Toshio

    2011-01-01

    Genotype characteristics and distribution of commensal Candida albicans should be studied to predict the development of candidiasis, however, extensive genotype analysis of commensal C. albicans has not been made. In this study, 508 C. albicans isolates were collected from patients with/without candidiasis and divided into 4 isolate groups (SG-1, oral cavity of non-candidiasis patients; SG-2, patients with cutaneous candidiasis; SG-3, patients with vaginal candidiasis; SG-4, patients with candidemia). These isolates were characterized to study the relationship between genotypes and pathogenicity using microsatellite analysis. Using CDC3 and CAI, 5 genotypes (I, 111: 115/33: 41; II, 115: 119/23: 23; III, 115: 123/18: 27; IV, 115: 123/33: 40; and V, 123: 127/32: 41) were found in 4.2%, 8.9%, 7.1%, 2.2% and 3.1% of the isolates, respectively. Genotypes II and III were commonly found in all isolate groups. These genotypes were further divided into 28 types by additional HIS3 and CAIII microsatellite markers. In this analysis, C. albicans with type 6 and type 23 was widely distributed as a commensal species in the oral cavity of non-candidiasis patients and found to be related with candidiasis development. Additionally, genotypes I and IV were found in SG-2 and/or SG-4, suggesting that the fungus with those genotypes is also involved in this development. In contrast, genotype V was not identified in any infective isolates.

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

    Science.gov (United States)

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

    2016-01-01

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

  2. 人类ARF1蛋白的重组表达及其与GDP/ADP的弱相互作用%Recombinant Expression and Weak Interactions with GDP/ADP of hARF1

    Institute of Scientific and Technical Information of China (English)

    郑芳芳; 阮路; 刘艳; 吴学记; 赵玉芬

    2011-01-01

    腺苷酸核糖基化因子1(ADP ribosylation factor 1,ARF1)是一种小G蛋白,负责调控细胞内的囊泡运输,从而影响细胞的生长发育.采用分子克隆的方法构建人类ARF1(hARF1)蛋白的重组质粒pET28 a-hARF1,并在大肠杆菌(Escherichia coli)BL21( DE3)中表达纯化,随后利用荧光光谱法和分子对接方法研究hARF1蛋白与嘌呤核苷酸( GDP/ADP)之间的弱相互作用.研究结果表明,重组表达的hARF1蛋白分子质量22 859.29 u,与理论值基本一致,其纯度大于95%,产率为5 mg/L左右;GDP/ADP与hARF1蛋白弱相互作用的结合常数分别为0.022 69和0.007 71(μmol/L)-1,说明hARF1蛋白选择性地结合GDP,这与细胞内hARF1蛋白只结合GDP的结论一致.%ADP ribosylation factor KADP ribosylation factor 1.ARF1) is a small GTP-binding protein,which is widely distributed in eukaryotic cells. ARF1 interacts with Golgi apparatus, plays the role of regulator of vesicle trafficking,and affects the development of various diseases. In this paper, the recombinant plasmid pET28a-hARFl was constructed, and hARFl protein was expressed in Escherichia coli BL2KDE3) and purified by affinity chromatograph and gel filtration. The results showed the molecular mass of hARFl protein was 22 859. 29 u,which was consistent with the theoretical value. The purity of hARFl protein was above 95% .while the yield was about 5 mg/L. At the same time, the interactions between hARFl and GDP/ADP were investigated by using fluorescence spectroscopy and MOE-Docking. It was found that hARFl and GDP/ADP had non-covalent interactions, and the binding constants were 0. 022 69 and 0. 007 71 (μmol/L)-1 respectively. It means that hARFl could bind to GDP selectively. The above-mentioned results were useful for the further study on the structure and function of hARFl.

  3. 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

  4. Resistance mechanisms to TP53-MDM2 inhibition identified by in vivo piggyBac transposon mutagenesis screen in an Arf(-/-) mouse model.

    Science.gov (United States)

    Chapeau, Emilie A; Gembarska, Agnieszka; Durand, Eric Y; Mandon, Emeline; Estadieu, Claire; Romanet, Vincent; Wiesmann, Marion; Tiedt, Ralph; Lehar, Joseph; de Weck, Antoine; Rad, Roland; Barys, Louise; Jeay, Sebastien; Ferretti, Stephane; Kauffmann, Audrey; Sutter, Esther; Grevot, Armelle; Moulin, Pierre; Murakami, Masato; Sellers, William R; Hofmann, Francesco; Jensen, Michael Rugaard

    2017-03-21

    Inhibitors of double minute 2 protein (MDM2)-tumor protein 53 (TP53) interaction are predicted to be effective in tumors in which the TP53 gene is wild type, by preventing TP53 protein degradation. One such setting is represented by the frequent CDKN2A deletion in human cancer that, through inactivation of p14ARF, activates MDM2 protein, which in turn degrades TP53 tumor suppressor. Here we used piggyBac (PB) transposon insertional mutagenesis to anticipate resistance mechanisms occurring during treatment with the MDM2-TP53 inhibitor HDM201. Constitutive PB mutagenesis in Arf(-/-) mice provided a collection of spontaneous tumors with characterized insertional genetic landscapes. Tumors were allografted in large cohorts of mice to assess the pharmacologic effects of HDM201. Sixteen out of 21 allograft models were sensitive to HDM201 but ultimately relapsed under treatment. A comparison of tumors with acquired resistance to HDM201 and untreated tumors identified 87 genes that were differentially and significantly targeted by the PB transposon. Resistant tumors displayed a complex clonality pattern suggesting the emergence of several resistant subclones. Among the most frequent alterations conferring resistance, we observed somatic and insertional loss-of-function mutations in transformation-related protein 53 (Trp53) in 54% of tumors and transposon-mediated gain-of-function alterations in B-cell lymphoma-extra large (Bcl-xL), Mdm4, and two TP53 family members, resulting in expression of the TP53 dominant negative truncations ΔNTrp63 and ΔNTrp73. Enhanced BCL-xL and MDM4 protein expression was confirmed in resistant tumors, as well as in HDM201-resistant patient-derived tumor xenografts. Interestingly, concomitant inhibition of MDM2 and BCL-xL demonstrated significant synergy in p53 wild-type cell lines in vitro. Collectively, our findings identify several potential mechanisms by which TP53 wild-type tumors may escape MDM2-targeted therapy.

  5. Transfer of p14ARF gene in drug-resistant human breast cancer MCF-7/Adr cells inhibits proliferation and reduces doxorubicin resistance

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To elucidate the effect of p14ARF gene on multidrug-resistant tumor cells. Methods: We transferred a p14ARF cDNA into p53-mutated MCF-7/Adr human breast cancer cells. Results: In this report we demonstrated for the first time that p14ARF expression was able to greatly inhibit the MCF-7/Adr cell proliferation. Furthermore, p14ARF expression resulted in decreases in MDR1 mRNA and P-glycoprotein production, which linked with the reducing resistance of MCF-7/Adr cells to doxorubicin. Conclusion: These results imply that drug resistance might be effectively reversed with the wild-type p14ARF expression in human breast cancer cells.

  6. Leonardo da Vinci’s anatomical drawings and Juan de Arfe y Villafañe

    Directory of Open Access Journals (Sweden)

    Röhrl, Boris

    2014-06-01

    Full Text Available The four volumes of the Varia commensuración para la escultura y architectura (1585–87 of the Spanish silversmith and sculptor Juan de Arfe y Villafañe represent an extensive compilation of Italian art techniques of the Renaissance. The sources for the Libro segundo, which includes systematic explanations on the theory of proportions, the skeleton and musculature have yet to be discovered. Its didactic and illustrative structure is unique in the context of sixteenth-century literature. The general layout and some details of the illustrations of the first three chapters seem to be derived from the Windsor convolute of anatomical drawings by Leonardo da Vinci.Los cuatros libros de Varia commensuración para la escultura y architectura (1585-1587 del platero y escultor Juan de Arfe y Villafañe representan un extenso compendio de las teorías y técnicas del Renacimiento italiano. Las fuentes del Libro segundo, que contiene explicaciones sistemáticas sobre la proporción de la figura humana, el esqueleto y la musculatura, aún no han sido descubiertas. La estructura didáctica y las ilustraciones son únicas en el contexto de la literatura del siglo XVI. El formato general y algunos detalles de las ilustraciones de los primeros tres capítulos parecen tener su origen en los dibujos anatómicos de Leonardo da Vinci conservados en el castillo de Windsor.

  7. Interaction between the triglyceride lipase ATGL and the arf1 activator GBF1

    KAUST Repository

    Ellong, Emy Njoh

    2011-07-18

    The Arf1 exchange factor GBF1 (Golgi Brefeldin A resistance factor 1) and its effector COPI are required for delivery of ATGL (adipose triglyceride lipase) to lipid droplets (LDs). Using yeast two hybrid, co-immunoprecipitation in mammalian cells and direct protein binding approaches, we report here that GBF1 and ATGL interact directly and in cells, through multiple contact sites on each protein. The C-terminal region of ATGL interacts with N-terminal domains of GBF1, including the catalytic Sec7 domain, but not with full-length GBF1 or its entire N-terminus. The N-terminal lipase domain of ATGL (called the patatin domain) interacts with two C-terminal domains of GBF1, HDS (Homology downstream of Sec7) 1 and HDS2. These two domains of GBF1 localize to lipid droplets when expressed alone in cells, but not to the Golgi, unlike the full-length GBF1 protein, which localizes to both. We suggest that interaction of GBF1 with ATGL may be involved in the membrane trafficking pathway mediated by GBF1, Arf1 and COPI that contributes to the localization of ATGL to lipid droplets.

  8. Interaction between the triglyceride lipase ATGL and the Arf1 activator GBF1.

    Directory of Open Access Journals (Sweden)

    Emy Njoh Ellong

    Full Text Available The Arf1 exchange factor GBF1 (Golgi Brefeldin A resistance factor 1 and its effector COPI are required for delivery of ATGL (adipose triglyceride lipase to lipid droplets (LDs. Using yeast two hybrid, co-immunoprecipitation in mammalian cells and direct protein binding approaches, we report here that GBF1 and ATGL interact directly and in cells, through multiple contact sites on each protein. The C-terminal region of ATGL interacts with N-terminal domains of GBF1, including the catalytic Sec7 domain, but not with full-length GBF1 or its entire N-terminus. The N-terminal lipase domain of ATGL (called the patatin domain interacts with two C-terminal domains of GBF1, HDS (Homology downstream of Sec7 1 and HDS2. These two domains of GBF1 localize to lipid droplets when expressed alone in cells, but not to the Golgi, unlike the full-length GBF1 protein, which localizes to both. We suggest that interaction of GBF1 with ATGL may be involved in the membrane trafficking pathway mediated by GBF1, Arf1 and COPI that contributes to the localization of ATGL to lipid droplets.

  9. A-RAF kinase functions in ARF6 regulated endocytic membrane traffic.

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    Elena Nekhoroshkova

    Full Text Available BACKGROUND: RAF kinases direct ERK MAPK signaling to distinct subcellular compartments in response to growth factor stimulation. METHODOLOGY/PRINCIPAL FINDINGS: Of the three mammalian isoforms A-RAF is special in that one of its two lipid binding domains mediates a unique pattern of membrane localization. Specific membrane binding is retained by an N-terminal fragment (AR149 that corresponds to a naturally occurring splice variant termed DA-RAF2. AR149 colocalizes with ARF6 on tubular endosomes and has a dominant negative effect on endocytic trafficking. Moreover actin polymerization of yeast and mammalian cells is abolished. AR149/DA-RAF2 does not affect the internalization step of endocytosis, but trafficking to the recycling compartment. CONCLUSIONS/SIGNIFICANCE: A-RAF induced ERK activation is required for this step by activating ARF6, as A-RAF depletion or inhibition of the A-RAF controlled MEK-ERK cascade blocks recycling. These data led to a new model for A-RAF function in endocytic trafficking.

  10. SWI/SNF mediates polycomb eviction and epigenetic reprogramming of the INK4b-ARF-INK4a locus

    NARCIS (Netherlands)

    S.K. Kia; M.M. Gorski (Marcin); S. Giannakopoulos (Stavros); C.P. Verrijzer (Peter)

    2008-01-01

    textabstractStable silencing of the INK4b-ARF-INK4a tumor suppressor locus occurs in a variety of human cancers, including malignant rhabdoid tumors (MRTs). MRTs are extremely aggressive cancers caused by the loss of the hSNF5 subunit of the SWI/SNF chromatin-remodeling complex. We found previously

  11. Four GTPases differentially regulate the Sec7 Arf-GEF to direct traffic at the trans-golgi network.

    Science.gov (United States)

    McDonold, Caitlin M; Fromme, J Christopher

    2014-09-29

    Traffic through the Golgi complex is controlled by small GTPases of the Arf and Rab families. Guanine nucleotide exchange factor (GEF) proteins activate these GTPases to control Golgi function, yet the full assortment of signals regulating these GEFs is unknown. The Golgi Arf-GEF Sec7 and the homologous BIG1/2 proteins are effectors of the Arf1 and Arl1 GTPases. We demonstrate that Sec7 is also an effector of two Rab GTPases, Ypt1 (Rab1) and Ypt31/32 (Rab11), signifying unprecedented signaling crosstalk between GTPase pathways. The molecular basis for the role of Ypt31/32 and Rab11 in vesicle formation has remained elusive. We find that Arf1, Arl1, and Ypt1 primarily affect the membrane localization of Sec7, whereas Ypt31/32 exerts a dramatic stimulatory effect on the nucleotide exchange activity of Sec7. The convergence of multiple signaling pathways on a master regulator reveals a mechanism for balancing incoming and outgoing traffic at the Golgi.

  12. Selective Protection of an ARF1-GTP Signaling Axis by a Bacterial Scaffold Induces Bidirectional Trafficking Arrest

    Directory of Open Access Journals (Sweden)

    Andrey S. Selyunin

    2014-03-01

    Full Text Available Bidirectional vesicular transport between the endoplasmic reticulum (ER and Golgi is mediated largely by ARF and Rab GTPases, which orchestrate vesicle fission and fusion, respectively. How their activities are coordinated in order to define the successive steps of the secretory pathway and preserve traffic directionality is not well understood in part due to the scarcity of molecular tools that simultaneously target ARF and Rab signaling. Here, we take advantage of the unique scaffolding properties of E. coli secreted protein G (EspG to describe the critical role of ARF1/Rab1 spatiotemporal coordination in vesicular transport at the ER-Golgi intermediate compartment. Structural modeling and cellular studies show that EspG induces bidirectional traffic arrest by tethering vesicles through select ARF1-GTP/effector complexes and local inactivation of Rab1. The mechanistic insights presented here establish the effectiveness of a small bacterial catalytic scaffold for studying complex processes and reveal an alternative mechanism of immune regulation by an important human pathogen.

  13. 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.

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

    Science.gov (United States)

    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

  15. Molecular basis of phosphatidylinositol 4-phosphate and ARF1 GTPase recognition by the FAPP1 pleckstrin homology (PH) domain.

    Science.gov (United States)

    He, Ju; Scott, Jordan L; Heroux, Annie; Roy, Siddhartha; Lenoir, Marc; Overduin, Michael; Stahelin, Robert V; Kutateladze, Tatiana G

    2011-05-27

    Four-phosphate-adaptor protein 1 (FAPP1) regulates secretory transport from the trans-Golgi network (TGN) to the plasma membrane. FAPP1 is recruited to the Golgi through binding of its pleckstrin homology (PH) domain to phosphatidylinositol 4-phosphate (PtdIns(4)P) and a small GTPase ADP-ribosylation factor 1 (ARF1). Despite the critical role of FAPP1 in membrane trafficking, the molecular basis of its dual function remains unclear. Here, we report a 1.9 Å resolution crystal structure of the FAPP1 PH domain and detail the molecular mechanisms of the PtdIns(4)P and ARF1 recognition. The FAPP1 PH domain folds into a seven-stranded β-barrel capped by an α-helix at one edge, whereas the opposite edge is flanked by three loops and the β4 and β7 strands that form a lipid-binding pocket within the β-barrel. The ARF1-binding site is located on the outer side of the β-barrel as determined by NMR resonance perturbation analysis, mutagenesis, and measurements of binding affinities. The two binding sites have little overlap, allowing FAPP1 PH to associate with both ligands simultaneously and independently. Binding to PtdIns(4)P is enhanced in an acidic environment and is required for membrane penetration and tubulation activity of FAPP1, whereas the GTP-bound conformation of the GTPase is necessary for the interaction with ARF1. Together, these findings provide structural and biochemical insight into the multivalent membrane anchoring by the PH domain that may augment affinity and selectivity of FAPP1 toward the TGN membranes enriched in both PtdIns(4)P and GTP-bound ARF1.

  16. Theoretical study of potential energy surface and vibrational spectra of ArF2 system

    Institute of Scientific and Technical Information of China (English)

    杨明晖; 谢代前; 鄢国森

    2000-01-01

    An ab initio potential energy surface (PES) of ArF2 system has been obtained by using MP4 calculation with a large basis set including bond functions. There are two local minimums on the PES: one is T-shaped and the other is L-shaped. The L-shaped minimum is the global minimum with a well depth of -119.62 cm- 1 at R = 0.3883nm. The T-shaped minimum has a well depth of -85.93cm -1 at R = 0.3486 nm. A saddle point is found at R = 0.3486 and θ = 61° with the well depth of -61.53 cm-1. The vibrational energy levels have been calculated by using VSCF-CI method. The results show that this PES supports 27 vibrational bound states, and the ground states are two degenerate states assigned to the L-type vibration.

  17. Theoretical study of potential energy surface and vibrational spectra of ArF2 system

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An ab initio potential energy surface (PES) of ArF2 system has been obtained by using MP4 calculation with a large basis set including bond functions. There are two local minimums on the PES: one is T-shaped and the other is L-shaped. The L-shaped minimum is the global minimum with a well depth of -119.62 cm-1 at R = 0.3883nm. The T-shaped minimum has a well depth of -85.93cm-1 at R = 0.3486 nm. A saddle point is found at R = 0.3486 and q = 61° with the well depth of -61.53 cm-1. The vibrational energy levels have been calculated by using VSCF-CI method. The results show that this PES supports 27 vibrational bound states, and the ground states are two degenerate states assigned to the L-type vibration.

  18. Whatever Happened to Illuga saga Gríðarfóstra?

    DEFF Research Database (Denmark)

    Lavender, Philip Thomas

    . It is found in 37 manuscript witnesses, but also in a number of other literary and textual formats. The relationships between these various formats - a passage from Saxo Grammaticus’ Gesta Danorum, Faroese ballads, Swedish ‘Stormaktstiden’ academic interventions and post-medieval Icelandic rímur......Never heard of Illuga saga Gríðarfóstra? You’re not alone. Alongside the canon of world literary treasures there lies a shady world of forgotten and abandoned texts. The focus of my doctoral research has been the revindication of one such work, not simply because humanities research revels...... – will be adumbrated and their production contexts analyzed in an attempt to account for how past audiences interacted with this quirky saga. The result hopefully provides a partial blueprint for the salvaging of similar literary flotsam and jetsam....

  19. Aberrant splicing of the DMP1-ARF-MDM2-p53 pathway in cancer.

    Science.gov (United States)

    Inoue, Kazushi; Fry, Elizabeth A

    2016-07-01

    Alternative splicing (AS) of mRNA precursors is a ubiquitous mechanism for generating numerous transcripts with different activities from one genomic locus in mammalian cells. The gene products from a single locus can thus have similar, dominant-negative or even opposing functions. Aberrant AS has been found in cancer to express proteins that promote cell growth, local invasion and metastasis. This review will focus on the aberrant splicing of tumor suppressor/oncogenes that belong to the DMP1-ARF-MDM2-p53 pathway. Our recent study shows that the DMP1 locus generates both tumor-suppressive DMP1α (p53-dependent) and oncogenic DMP1β (p53-independent) splice variants, and the DMP1β/α ratio increases with neoplastic transformation of breast epithelial cells. This process is associated with high DMP1β protein expression and shorter survival of breast cancer (BC) patients. Accumulating pieces of evidence show that ARF is frequently inactivated by aberrant splicing in human cancers, demonstrating its involvement in human malignancies. Splice variants from the MDM2 locus promote cell growth in culture and accelerate tumorigenesis in vivo. Human cancers expressing these splice variants are associated with advanced stage/metastasis, and thus have negative clinical impacts. Although they lack most of the p53-binding domain, their activities are mostly dependent on p53 since they bind to wild-type MDM2. The p53 locus produces splice isoforms that have either favorable (β/γ at the C-terminus) or negative impact (Δ40, Δ133 at the N-terminus) on patients' survival. As the oncogenic AS products from these loci are expressed only in cancer cells, they may eventually become targets for molecular therapies.

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

    Directory of Open Access Journals (Sweden)

    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

  1. p14ARF post-transcriptional regulation of nuclear cyclin D1 in MCF-7 breast cancer cells: discrimination between a good and bad prognosis?

    Directory of Open Access Journals (Sweden)

    Eileen M McGowan

    Full Text Available As part of a cell's inherent protection against carcinogenesis, p14ARF is upregulated in response to hyperproliferative signalling to induce cell cycle arrest. This property makes p14ARF a leading candidate for cancer therapy. This study explores the consequences of reactivating p14ARF in breast cancer and the potential of targeting p14ARF in breast cancer treatment. Our results show that activation of the p14ARF-p53-p21-Rb pathway in the estrogen sensitive MCF-7 breast cancer cells induces many hallmarks of senescence including a large flat cell morphology, multinucleation, senescence-associated-β-gal staining, and rapid G1 and G2/M phase cell cycle arrest. P14ARF also induces the expression of the proto-oncogene cyclin D1, which is most often associated with a transition from G1-S phase and is highly expressed in breast cancers with poor clinical prognosis. In this study, siRNA knockdown of cyclin D1, p21 and p53 show p21 plays a pivotal role in the maintenance of high cyclin D1 expression, cell cycle and growth arrest post-p14ARF induction. High p53 and p14ARF expression and low p21/cyclin D1 did not cause cell-cycle arrest. Knockdown of cyclin D1 stops proliferation but does not reverse senescence-associated cell growth. Furthermore, cyclin D1 accumulation in the nucleus post-p14ARF activation correlated with a rapid loss of nucleolar Ki-67 protein and inhibition of DNA synthesis. Latent effects of the p14ARF-induced cellular processes resulting from high nuclear cyclin D1 accumulation included a redistribution of Ki-67 into the nucleoli, aberrant nuclear growth (multinucleation, and cell proliferation. Lastly, downregulation of cyclin D1 through inhibition of ER abrogated latent recurrence. The mediation of these latent effects by continuous expression of p14ARF further suggests a novel mechanism whereby dysregulation of cyclin D1 could have a double-edged effect. Our results suggest that p14ARF induced-senescence is related to late

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. 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.

  5. Interleukin 17-Mediated Host Defense against Candida albicans

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Prediction

    CERN Document Server

    Sornette, Didier

    2010-01-01

    This chapter first presents a rather personal view of some different aspects of predictability, going in crescendo from simple linear systems to high-dimensional nonlinear systems with stochastic forcing, which exhibit emergent properties such as phase transitions and regime shifts. Then, a detailed correspondence between the phenomenology of earthquakes, financial crashes and epileptic seizures is offered. The presented statistical evidence provides the substance of a general phase diagram for understanding the many facets of the spatio-temporal organization of these systems. A key insight is to organize the evidence and mechanisms in terms of two summarizing measures: (i) amplitude of disorder or heterogeneity in the system and (ii) level of coupling or interaction strength among the system's components. On the basis of the recently identified remarkable correspondence between earthquakes and seizures, we present detailed information on a class of stochastic point processes that has been found to be particu...

  9. 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.

  10. 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.

  11. Radiolabel release microassay for phagocytic killing of Candida albicans

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. p16INK4A and p14ARF Gene Promoter Hypermethylation as Prognostic Biomarker in Oral and Oropharyngeal Squamous Cell Carcinoma: A Review

    Science.gov (United States)

    Al-Kaabi, A.; van Bockel, L. W.; Pothen, A. J.; Willems, S. M.

    2014-01-01

    Head and neck squamous cell carcinoma is a heterogeneous group of tumors with each subtype having a distinct histopathological and molecular profile. Most tumors share, to some extent, the same multistep carcinogenic pathways, which include a wide variety of genetic and epigenetic changes. Epigenetic alterations represent all changes in gene expression patterns that do not alter the actual DNA sequence. Recently, it has become clear that silencing of cancer related genes is not exclusively a result of genetic changes such as mutations or deletions, but it can also be regulated on epigenetic level, mostly by means of gene promoter hypermethylation. Results from recent studies have demonstrated that DNA methylation patterns contain tumor-type-specific signatures, which could serve as biomarkers for clinical outcome in the near future. The topic of this review discusses gene promoter hypermethylation in oral and oropharyngeal squamous cell carcinoma (OSCC). The main objective is to analyse the available data on gene promoter hypermethylation of the cell cycle regulatory proteins p16INK4A and p14ARF and to investigate their clinical significance as novel biomarkers in OSCC. Hypermethylation of both genes seems to possess predictive properties for several clinicopathological outcomes. We conclude that the methylation status of p16INK4A is definitely a promising candidate biomarker for predicting clinical outcome of OSCC, especially for recurrence-free survival. PMID:24803719

  13. p16INK4A and p14ARF Gene Promoter Hypermethylation as Prognostic Biomarker in Oral and Oropharyngeal Squamous Cell Carcinoma: A Review

    Directory of Open Access Journals (Sweden)

    A. Al-Kaabi

    2014-01-01

    Full Text Available Head and neck squamous cell carcinoma is a heterogeneous group of tumors with each subtype having a distinct histopathological and molecular profile. Most tumors share, to some extent, the same multistep carcinogenic pathways, which include a wide variety of genetic and epigenetic changes. Epigenetic alterations represent all changes in gene expression patterns that do not alter the actual DNA sequence. Recently, it has become clear that silencing of cancer related genes is not exclusively a result of genetic changes such as mutations or deletions, but it can also be regulated on epigenetic level, mostly by means of gene promoter hypermethylation. Results from recent studies have demonstrated that DNA methylation patterns contain tumor-type-specific signatures, which could serve as biomarkers for clinical outcome in the near future. The topic of this review discusses gene promoter hypermethylation in oral and oropharyngeal squamous cell carcinoma (OSCC. The main objective is to analyse the available data on gene promoter hypermethylation of the cell cycle regulatory proteins p16INK4A and p14ARF and to investigate their clinical significance as novel biomarkers in OSCC. Hypermethylation of both genes seems to possess predictive properties for several clinicopathological outcomes. We conclude that the methylation status of p16INK4A is definitely a promising candidate biomarker for predicting clinical outcome of OSCC, especially for recurrence-free survival.

  14. Chimeric negative regulation of p14ARF and TBX1 by a t(9;22) translocation associated with melanoma, deafness, and DNA repair deficiency.

    Science.gov (United States)

    Tan, Xiaohui; Anzick, Sarah L; Khan, Sikandar G; Ueda, Takahiro; Stone, Gary; Digiovanna, John J; Tamura, Deborah; Wattendorf, Daniel; Busch, David; Brewer, Carmen C; Zalewski, Christopher; Butman, John A; Griffith, Andrew J; Meltzer, Paul S; Kraemer, Kenneth H

    2013-09-01

    Melanoma is the most deadly form of skin cancer and DiGeorge syndrome (DGS) is the most frequent interstitial deletion syndrome. We characterized a novel balanced t(9;22)(p21;q11.2) translocation in a patient with melanoma, DNA repair deficiency, and features of DGS including deafness and malformed inner ears. Using chromosome sorting, we located the 9p21 breakpoint in CDKN2A intron 1. This resulted in underexpression of the tumor suppressor p14 alternate reading frame (p14ARF); the reduced DNA repair was corrected by transfection with p14ARF. Ultraviolet radiation-type p14ARF mutations in his melanoma implicated p14ARF in its pathogenesis. The 22q11.2 breakpoint was located in a palindromic AT-rich repeat (PATRR22). We identified a new gene, FAM230A, that contains PATRR22 within an intron. The 22q11.2 breakpoint was located 800 kb centromeric to TBX1, which is required for inner ear development. TBX1 expression was greatly reduced. The translocation resulted in a chimeric transcript encoding portions of p14ARF and FAM230A. Inhibition of chimeric p14ARF-FAM230A expression increased p14ARF and TBX1 expression and improved DNA repair. Expression of the chimera in normal cells produced dominant negative inhibition of p14ARF. Similar chimeric mRNAs may mediate haploinsufficiency in DGS or dominant negative inhibition of other genes such as those involved in melanoma.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Antimicrobial Activity of Five Medicinal Plants on Candida Albicans

    Directory of Open Access Journals (Sweden)

    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.

  20. 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

  1. 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.

  2. 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

  3. PERTUMBUHAN CANDIDA ALBICANS PADA PERMUKAAN POLIESTER EBP-2421

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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.

  6. Interaction of ARF-1.1 and neuronal calcium sensor-1 in the control of the temperature-dependency of locomotion in Caenorhabditis elegans

    Science.gov (United States)

    Todd, Paul A. C.; McCue, Hannah V.; Haynes, Lee P.; Barclay, Jeff W.; Burgoyne, Robert D.

    2016-01-01

    Neuronal calcium sensor-1 (NCS-1) mediates changes in cellular function by regulating various target proteins. Many potential targets have been identified but the physiological significance of only a few has been established. Upon temperature elevation, Caenorhabditis elegans exhibits reversible paralysis. In the absence of NCS-1, worms show delayed onset and a shorter duration of paralysis. This phenotype can be rescued by re-expression of ncs-1 in AIY neurons. Mutants with defects in four potential NCS-1 targets (arf-1.1, pifk-1, trp-1 and trp-2) showed qualitatively similar phenotypes to ncs-1 null worms, although the effect of pifk-1 mutation on time to paralysis was considerably delayed. Inhibition of pifk-1 also resulted in a locomotion phenotype. Analysis of double mutants showed no additive effects between mutations in ncs-1 and trp-1 or trp-2. In contrast, double mutants of arf-1.1 and ncs-1 had an intermediate phenotype, consistent with NCS-1 and ARF-1.1 acting in the same pathway. Over-expression of arf-1.1 in the AIY neurons was sufficient to rescue partially the phenotype of both the arf-1.1 and the ncs-1 null worms. These findings suggest that ARF-1.1 interacts with NCS-1 in AIY neurons and potentially pifk-1 in the Ca2+ signaling pathway that leads to inhibited locomotion at an elevated temperature. PMID:27435667

  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. Intratumoral Immunization by p19Arf and Interferon-β Gene Transfer in a Heterotopic Mouse Model of Lung Carcinoma

    Directory of Open Access Journals (Sweden)

    João Paulo Portela Catani

    2016-12-01

    Full Text Available Therapeutic strategies that act by eliciting and enhancing antitumor immunity have been clinically validated as an effective treatment modality but may benefit from the induction of both cell death and immune activation as primary stimuli. Using our AdRGD-PG adenovector platform, we show here for the first time that in situ gene transfer of p19Arf and interferon-β (IFNβ in the LLC1 mouse model of lung carcinoma acts as an immunotherapy. Although p19Arf is sufficient to induce cell death, only its pairing with IFNβ significantly induced markers of immunogenic cell death. In situ gene therapy with IFNβ, either alone or in combination with p19Arf, could retard tumor progression, but only the combined treatment was associated with a protective immune response. Specifically in the case of combined intratumoral gene transfer, we identified 167 differentially expressed genes when using microarray to evaluate tumors that were treated in vivo and confirmed the activation of CCL3, CXCL3, IL1α, IL1β, CD274, and OSM, involved in immune response and chemotaxis. Histologic evaluation revealed significant tumor infiltration by neutrophils, whereas functional depletion of granulocytes ablated the antitumor effect of our approach. The association of in situ gene therapy with cisplatin resulted in synergistic elimination of tumor progression. In all, in situ gene transfer with p19Arf and IFNβ acts as an immunotherapy involving recruitment of neutrophils, a desirable but previously untested outcome, and this approach may be allied with chemotherapy, thus providing significant antitumor activity and warranting further development for the treatment of lung carcinoma.

  9. Generation of intense 10-ps, 193-nm pulses using simple distributed feedback dye lasers and an ArF(*) amplifier.

    Science.gov (United States)

    Hatten, D L; Cui, Y; Iii, W T; Mikes, T; Goldhar, J

    1992-11-20

    A pair of holographic distributed feedback dye lasers is used to generate 10-ps pulses at two selected wavelengths that are mixed in a BBO crystal to produce a pulse ~ 10 ps in duration at 193 nm. This seed pulse is subsequently amplified in an ArF(*) excimer laser to an energy of 10-15 mJ with <40 microJ in amplified spontaneous emission. The pulses are nearly transform limited and diffraction limited.

  10. ARF6-Regulated Endocytosis of Growth Factor Receptors Links Cadherin-Based Adhesion to Canonical Wnt Signaling in Epithelia

    OpenAIRE

    Pellon-Cardenas, Oscar; Clancy, James; Uwimpuhwe, Henriette; D'Souza-Schorey, Crislyn

    2013-01-01

    Wnt signaling has an essential role in embryonic development as well as stem/progenitor cell renewal, and its aberrant activation is implicated in many diseases, including several cancers. β-Catenin is a critical component of Wnt-mediated transcriptional activation. Here we show that ARF6 activation during canonical Wnt signaling promotes the intracellular accumulation of β-catenin via a mechanism that involves the endocytosis of growth factor receptors and robust activation of extracellular ...

  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. The ArfGEF GBF-1 Is Required for ER Structure, Secretion and Endocytic Transport in C. elegans.

    Directory of Open Access Journals (Sweden)

    Karin B Ackema

    Full Text Available Small GTPases of the Sar/Arf family are essential to generate transport containers that mediate communication between organelles of the secretory pathway. Guanine nucleotide exchange factor (GEFs activate the small GTPases and help their anchorage in the membrane. Thus, GEFs in a way temporally and spatially control Sar1/Arf1 GTPase activation. We investigated the role of the ArfGEF GBF-1 in C. elegans oocytes and intestinal epithelial cells. GBF-1 localizes to the cis-Golgi and is part of the t-ER-Golgi elements. GBF-1 is required for secretion and Golgi integrity. In addition, gbf-1(RNAi causes the ER reticular structure to become dispersed, without destroying ER exit sites (ERES because the ERES protein SEC-16 was still localized in distinct punctae at t-ER-Golgi units. Moreover, GBF-1 plays a role in receptor-mediated endocytosis in oocytes, without affecting recycling pathways. We find that both the yolk receptor RME-2 and the recycling endosome-associated RAB-11 localize similarly in control and gbf-1(RNAi oocytes. While RAB5-positive early endosomes appear to be less prominent and the RAB-5 levels are reduced by gbf-1(RNAi in the intestine, RAB-7-positive late endosomes were more abundant and formed aggregates and tubular structures. Our data suggest a role for GBF-1 in ER structure and endosomal traffic.

  13. The ArfGAP2/3 Glo3 and ergosterol collaborate in transport of a subset of cargoes

    Directory of Open Access Journals (Sweden)

    Alejandro F. Estrada

    2015-07-01

    Full Text Available Proteins reach the plasma membrane through the secretory pathway in which the trans Golgi network (TGN acts as a sorting station. Transport from the TGN to the plasma membrane is maintained by a number of different pathways that act either directly or via the endosomal system. Here we show that a subset of cargoes depends on the ArfGAP2/3 Glo3 and ergosterol to maintain their proper localization at the plasma membrane. While interfering with neither ArfGAP2/3 activity nor ergosterol biosynthesis individually significantly altered plasma membrane localization of the tryptophan transporter Tat2, the general amino acid permease Gap1 and the v-SNARE Snc1, in a Δglo3 Δerg3 strain those proteins accumulated in internal endosomal structures. Export from the TGN to the plasma membrane and recycling from early endosomes appeared unaffected as the chitin synthase Chs3 that travels along these routes was localized normally. Our data indicate that a subset of proteins can reach the plasma membrane efficiently but after endocytosis becomes trapped in endosomal structures. Our study supports a role for ArfGAP2/3 in recycling from endosomes and in transport to the vacuole/lysosome.

  14. 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.

  15. Influence of resin properties to resist performance at ArF lithography

    Science.gov (United States)

    Yoon, Sangwoong; Kim, Myungsun; Lee, Hong; Kim, Do Y.; Kim, Young Hoon; Kim, Boo Deuk; Kim, Jae Hyun; Kim, Kyung-Mee; Lee, Shi Yong; Kim, Young Ho; Chon, Sang-Mun

    2004-05-01

    The ArF resist has been evaluated focusing on resin character such as molecular weight, monomer composition and polydispersity (Pd). The resin properties were investigated to elucidate that which parameter was affected to the line edge roughness (LER). The Pd was correlated with LER. As the Pd was large, the LER was small. The resin molecular weight and monomer composition were affected to their vertical profile. Low molecular weight portion rich resin resulted in round and t-top profile, whilst high molecular weight rich resin resulted in square profile. The amount of lower molecular weight fraction was changed by purification method. The lower molecular weight resin caused severe tapered profile. It was concluded that 1) shift of Mw to smaller and 2) higher content of low molecular size fraction lead to rounded and tapered pattern profile. Lot-to-lot stable good pattern profile has achieved by controlling polymer molecular weight and content of low molecular size fraction in small variation range.

  16. Macrophages, Inflammation, and Tumor Suppressors: ARF, a New Player in the Game

    Directory of Open Access Journals (Sweden)

    Paqui G. Través

    2012-01-01

    Full Text Available The interaction between tumor progression and innate immune system has been well established in the last years. Indeed, several lines of clinical evidence indicate that immune cells such as tumor-associated macrophages (TAMs interact with tumor cells, favoring growth, angiogenesis, and metastasis of a variety of cancers. In most tumors, TAMs show properties of an alternative polarization phenotype (M2 characterized by the expression of a series of chemokines, cytokines, and proteases that promote immunosuppression, tumor proliferation, and spreading of the cancer cells. Tumor suppressor genes have been traditionally linked to the regulation of cancer progression; however, a growing body of evidence indicates that these genes also play essential roles in the regulation of innate immunity pathways through molecular mechanisms that are still poorly understood. In this paper, we provide an overview of the immunobiology of TAMs as well as what is known about tumor suppressors in the context of immune responses. Recent advances regarding the role of the tumor suppressor ARF as a regulator of inflammation and macrophage polarization are also reviewed.

  17. Photo-triggering and secondary electron produced ionization in electric discharge ArF* excimer lasers

    Science.gov (United States)

    Xiong, Zhongmin; Kushner, Mark J.

    2011-10-01

    Electric discharge excimer lasers are sustained in multi-atmosphere attaching gas mixtures that are typically preionized to enable a reproducible, uniform glow, which maximizes optical quality and gain. This preionization is often accomplished using UV light produced by a corona discharge within the plasma cavity. To quantify the relationship between corona discharge properties and those of the laser discharge, the triggering of electron avalanche by preionizing UV light in an electric discharge-pumped ArF* excimer laser was numerically investigated using a two-dimensional model. The preionizing UV fluxes were generated by a corona-bar discharge driven by the same voltage pulse as the main discharge sustained in a multi-atmospheric Ne/Ar/Xe/F2 gas mixture. The resulting peak photo-electron density in the inter-electrode spacing is around 108 cm-3, and its distribution is biased toward the UV source. The preionization density increases with increasing dielectric constant and capacitance of the corona bar. The symmetry and uniformity of the discharge are, however, improved significantly once the main avalanche develops. In addition to bulk electron impact ionization, the ionization generated by sheath accelerated secondary electrons was found to be important in sustaining the discharge current at experimentally observed values. At peak current, the magnitude of the ionization by sheath accelerated electrons is comparable to that from bulk electron impact in the vicinity of the cathode.

  18. Evaluation of IDEALSmile for 90-nm FLASH memory contact holes imaging with ArF scanner

    Science.gov (United States)

    Cantu, Pietro; Capetti, Gianfranco; Loi, Sara; Lupo, Marco; Pepe, Annalisa; Saitoh, Kenji; Yamazoe, Kenji; Hasegawa, Yasuo; Iwasa, Junji; Toublan, Olivier R.

    2004-05-01

    According to sizes dictated by ITRS road map, contact holes are one of the most challenging features to be printed in the semiconductor manufacturing process. The development of 90[nm] technology FLASH memories requires a robust solution for printing contact holes down to 100[nm] on 200[nm] pitch. The delay of NGL development as well as open issues related to 157[nm] scanner introduction pushes the industry to find a solution for printing such tight features using existing ArF scanner. IDEALSmile technology from Canon was proven to be a good candidate for achieving such high resolution with sufficiently large through pitch process window using a binary mask, relatively simple to be manufactured, with a modified illumination and single exposure, with no impact on throughput and without any increase of cost of ownership. This paper analyses main issues related to the introduction of this new resolution enhancement technology on a real FLASH memory device, highlighting advantages as well as known problems still under investigation.

  19. Interaction of ArF laser with dental hard tissue (AEM Study

    Directory of Open Access Journals (Sweden)

    Abbas Majdabadi

    2016-07-01

    Full Text Available Background and Aims: Nowadays lasers are used as alternatives to the tooth preparation because of reducing pain and bloodshed. The aim of this study was to observe the effect of ArF laser on the dental hard tissues. Materials and Methods: For this research human molar teeth with no caries or dental restoration and enamel cracks were used. Irradiation laser energies were taken 95, 70 and 50 mJ for enamel and 80, 70 and 50 mJ for dentine. Then, for each of energy values pulse numbers (repetition rate were adjusted at 200, 400, 600, 800, 1000 and 1500. Ablation was carried out without water spray on both enamel and dentine. Finally, the dimensions of ablated areas were measured by using a camera connected to the computer and results were applied in graphs. Results: For each energy value, the ablation dimension increased by increasing pulse numbers. Ablation depth in dentine was more than that of for enamel. Trends of graphs for dentine and enamel were the same. SEM images of ablations by 95 mJ energy on enamel and 80 mJ energy on dentine showed sharp edges. Conclusion: Ablation depths increased by increasing pulse numbers, for each energy level. However, this increase was not that as expected, because the lack of water spray while irradiating.

  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. 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.

  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. The ARF, AUX/IAA and GH3 gene families in citrus: genome-wide identification and expression analysis during fruitlet drop from abscission zone A.

    Science.gov (United States)

    Xie, Rangjin; Pang, Shaoping; Ma, Yanyan; Deng, Lie; He, Shaolan; Yi, Shilai; Lv, Qiang; Zheng, Yongqiang

    2015-12-01

    Completion of the whole genome sequencing of citrus enabled us to perform genome-wide identification and functional analysis of the gene families involved in agronomic traits and morphological diversity of citrus. In this study, 22 CitARF, 11 CitGH3 and 26 CitAUX/IAA genes were identified in citrus, respectively. Phylogenetic analysis revealed that all the genes of each gene family could be subdivided into three groups and showed strong evolutionary conservation. The GH3 and AUX/IAA gene families shrank and ARF gene family was highly conserved in the citrus genome after speciation from Arabidopsis thaliana. Tissue-specific expression profiles revealed that 54 genes were expressed in at least one tissue while just 5 genes including CitARF07, CitARF20, CitGH3.04, CitAUX/IAA25 and CitAUX/IAA26 with very low expression level in all tissues tested, suggesting that the CitARF, CitGH3 and CitAUX/IAA gene families played important roles in the development of citrus organs. In addition, our data found that the expression of 2 CitARF, 4 CitGH3 and 4 AUX/IAA genes was affected by IAA treatment, and 7 genes including, CitGH3.04, CitGH3.07, CitAUX/IAA03, CitAUX/IAA04, CitAUX/IAA18, CitAUX/IAA19 and CitAUX/IAA23 were related to fruitlet abscission. This study provides a foundation for future studies on elucidating the precise role of citrus ARF, GH3 and AUX/IAA genes in early steps of auxin signal transduction and open up a new opportunity to uncover the molecular mechanism underlying citrus fruitlet abscission.

  4. Lime pretreatment of sugar beet pulp and evaluation of synergy between ArfA, ManA and XynA from Clostridium cellulovorans on the pretreated substrate.

    Science.gov (United States)

    Dredge, Roselyn; Radloff, Sarah E; van Dyk, J Susan; Pletschke, Brett I

    2011-10-01

    Sugar beet pulp (SBP) is a waste product from the sugar beet industry and could be used as a potential biomass feedstock for second generation biofuel technology. Pretreatment of SBP with 'slake lime' (calcium hydroxide) was investigated using a 2(3) factorial design and the factors examined included lime loading, temperature and time. The pretreatment was evaluated for its ability to enhance enzymatic degradation using a combination of three hemicellulases, namely ArfA (an arabinofuranosidase), ManA (an endo-mannanase) and XynA (an endo-xylanase) from C. cellulovorans to determine the conditions under which optimal activity was facilitated. Optimal pretreatment conditions were found to be 0.4 g lime/g SBP, with 36 h digestion at 40 °C. The synergistic interactions between ArfA, ManA and XynA from C. cellulovorans were subsequently investigated on the pretreated SBP. The highest degree of synergy was observed at a protein ratio of 75% ArfA to 25% ManA, with a specific activity of 2.9 U/g protein. However, the highest activity was observed at 4.2 U/g protein at 100% ArfA. This study demonstrated that lime treatment enhanced enzymatic hydrolysis of SBP. The ArfA was the most effective hemicellulase for release of sugars from pretreated SBP, but the synergy with the ManA indicated that low levels of mannan in SBP were probably masking the access of the ArfA to its substrate. XynA displayed no synergy with the other two hemicellulases, indicating that the xylan in the SBP was not hampering the access of ArfA or ManA to their substrates and was not closely associated with the mannan and arabinan in the SBP.

  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. 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.

  7. 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.

  8. 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.

  9. 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, ...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Interactions of Candida albicans with host epithelial surfaces

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

  16. 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.

  17. 香蕉ARF3基因全长克隆及其对枯萎病菌的响应特性分析%Cloning the Full-length cDNA of ARF3 Gene from Banana (Musa acuminata) and Characterizing Its Response to Banana Fusarium

    Institute of Scientific and Technical Information of China (English)

    杨浩; 杜中军; 徐立; 唐志鹏; 李志英

    2013-01-01

    ARF3 gene is one of member of the ARF gene family. The functions of ARF3 gene are considered to involve in cell signal transduction, membrane transportation and vesicle transporting. This study has designed four specific primers according to the core sequence fragment, which was obtained from banana transcriptome. The full cDNA of the ARF3 was cloned from banana (Musa acuminata) by using the approaches of RACE and PCR, the cloned gene was named MuARF3. The gene sequence of 1 427 bp contains an open reading frame (ORF) of 1 166 bp in length that encodes 338 amino acid residuals. BLAST analysis showed that the full-length nucleotide sequence of the ARF3 has a range from 69% to 74% similarities to the reported ARF3 gene of the other plants as well as from 81% to 93% similarities in amino acid sequence. Through infecting banana roots inoculated with banana Fusarium race 4, the expression level of MuARF3 was dramatically elevated to the highest point at 12 h after inoculation and then gradually declined with time elapse. Therefore, the cloned MuARF3 gene has active response to infection of Fusarium physiological race No.4, which might provide a reference for the further use of the gene.%  ARF3基因属于ARF基因家族的成员,主要功能是参与细胞信号转导、跨膜运输及囊泡转运.本研究根据已获得的基因片段设计4条特异性引物,采用RACE技术克隆获得了香蕉ARF3基因cDNA全长序列,命名为MuARF3.该基因序列全长共1427 bp,开放阅读框长度为1166 bp,共编码338个氨基酸.BLAST结果显示,香蕉ARF3基因全长核苷酸序列与已报道的其它植物ARF3具有69%~74%的相似性,氨基酸序列有81%~93%的相似性.用香蕉枯萎病菌4号生理小种侵染香蕉根系后,分析得出的结果表明,侵染根系后香蕉ARF3基因的表达量在侵染后12 h达到最高,并且随着时间推移逐渐降低.由此说明本研究获得的MuARF3基因对香蕉枯萎病菌4号生理小种侵染具有应急

  18. ULAKBİM Cahit Arf Bilgi Merkezinde Belge Sağlamanın Maliyet Analizi

    Directory of Open Access Journals (Sweden)

    Yurdagül Ünal

    2005-06-01

    Full Text Available This study aims to review the document delivery requests submitted to the Cahit Arf Information Center, Document Delivery Services Unit of the National Academic Network and Information Center (ULAKBIM. It aims to determine which one is more economic and dispatch in terms of the length of time (in days it takes to fill a request and the unit cost of supplying requests from printed journals and electronic ones. We tracked the data with regards to document delivery requests that were submitted to the Unit for the year 2000 on October and November. Information (labour cost, corrective maintenance, cleaning, communication, etc. was obtained from the Center to calculate the unit cost. In order to calculate the unit cost, the cost types such as labour cost, raw product and general cost were identified and the total cost was divided to the total number of document delivery request. The unit cost of supplying an article in the year 2000 was found as about 3 million Turkish Liras (According to the Consumer Price Index of September 2004, the unit cost of a supplied document was 8.690.541 Turkish Liras. From submission to the mailing of the document, it took a total of 15 days to fill a document delivery request. Since the procedure of supplying the electronic or printed documents was not different in the Unit, the length of time and unit cost were almost the same for supplying the documents from printed journals and electronic ones. Bu araştırmada amaç, Ulusal Akademik Ağ ve Bilgi Merkezi (ULAKBİM Cahit Arf Bilgi Merkezi (CABİM Belge Sağlama Hizmetleri Biriminde basılı dergilerden sağlanan isteklerle elektronik dergilerden sağlanan istekleri süre ve birim maliyet açısından karşılaştırarak hangisinin daha hızlı ve ekonomik olduğunu belirlemektir. Çalışmada, 2000 yılının Ekim ve Kasım aylarında Birime yapılan 9213 belge sağlama isteği izlenmiş ve bu isteklerin birim maliyetim bulmak için gerekli veriler (işçilik, bak

  19. 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.

  20. ARF6 promotes the formation of Rac1 and WAVE-dependent ventral F-actin rosettes in breast cancer cells in response to epidermal growth factor.

    Directory of Open Access Journals (Sweden)

    Valentina Marchesin

    Full Text Available Coordination between actin cytoskeleton assembly and localized polarization of intracellular trafficking routes is crucial for cancer cell migration. ARF6 has been implicated in the endocytic recycling of surface receptors and membrane components and in actin cytoskeleton remodeling. Here we show that overexpression of an ARF6 fast-cycling mutant in MDA-MB-231 breast cancer-derived cells to mimick ARF6 hyperactivation observed in invasive breast tumors induced a striking rearrangement of the actin cytoskeleton at the ventral cell surface. This phenotype consisted in the formation of dynamic actin-based podosome rosette-like structures expanding outward as wave positive for F-actin and actin cytoskeleton regulatory components including cortactin, Arp2/3 and SCAR/WAVE complexes and upstream Rac1 regulator. Ventral rosette-like structures were similarly induced in MDA-MB-231 cells in response to epidermal growth factor (EGF stimulation and to Rac1 hyperactivation. In addition, interference with ARF6 expression attenuated activation and plasma membrane targeting of Rac1 in response to EGF treatment. Our data suggest a role for ARF6 in linking EGF-receptor signaling to Rac1 recruitment and activation at the plasma membrane to promote breast cancer cell directed migration.

  1. A novel zinc finger protein Zfp277 mediates transcriptional repression of the Ink4a/arf locus through polycomb repressive complex 1

    DEFF Research Database (Denmark)

    Negishi, Masamitsu; Saraya, Atsunori; Mochizuki, Shinobu

    2010-01-01

    . METHODOLOGY/PRINCIPAL FINDINGS: We examined the function of Zinc finger domain-containing protein 277 (Zfp277), a novel zinc finger protein that interacts with the PcG protein Bmi1. Zfp277 binds to the Ink4a/Arf locus in a Bmi1-independent manner and interacts with polycomb repressor complex (PRC) 1 through......BACKGROUND: Polycomb group (PcG) proteins play a crucial role in cellular senescence as key transcriptional regulators of the Ink4a/Arf tumor suppressor gene locus. However, how PcG complexes target and contribute to stable gene silencing of the Ink4a/Arf locus remains little understood...... direct interaction with Bmi1. Loss of Zfp277 in mouse embryonic fibroblasts (MEFs) caused dissociation of PcG proteins from the Ink4a/Arf locus, resulting in premature senescence associated with derepressed p16(Ink4a) and p19(Arf) expression. Levels of both Zfp277 and PcG proteins inversely correlated...

  2. The Solanum lycopersicum AUXIN RESPONSE FACTOR 7 (SlARF7) mediates cross-talk between auxin and gibberellin signalling during tomato fruit set and development

    Science.gov (United States)

    de Jong, Maaike; Wolters-Arts, Mieke; García-Martínez, José L.; Mariani, Celestina; Vriezen, Wim H.

    2011-01-01

    Transgenic tomato plants (Solanum lycopersicum L.) with reduced mRNA levels of AUXIN RESPONSE FACTOR 7 (SlARF7) form parthenocarpic fruits with morphological characteristics that seem to be the result of both increased auxin and gibberellin (GA) responses during fruit growth. This paper presents a more detailed analysis of these transgenic lines. Gene expression analysis of auxin-responsive genes show that SlARF7 may regulate only part of the auxin signalling pathway involved in tomato fruit set and development. Also, part of the GA signalling pathway was affected by the reduced levels of SlARF7 mRNA, as morphological and molecular analyses display similarities between GA-induced fruits and fruits formed by the RNAi SlARF7 lines. Nevertheless, the levels of GAs were strongly reduced compared with that in seeded fruits. These findings indicate that SlARF7 acts as a modifier of both auxin and gibberellin responses during tomato fruit set and development. PMID:20937732

  3. 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...

  4. 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

  5. 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...

  6. 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.

  7. 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...

  8. 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.

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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).

  12. 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.

  13. 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).

  14. Aberrant DNA methylation of ESR1 and p14ARF genes could be useful as prognostic indicators in osteosarcoma

    Directory of Open Access Journals (Sweden)

    Sonaglio V

    2013-06-01

    Full Text Available Viviane Sonaglio,1 Ana C de Carvalho,2 Silvia R C Toledo,3,4 Carolina Salinas-Souza,3,4 André L Carvalho,5 Antonio S Petrilli,3 Beatriz de Camargo,6 André L Vettore21Pediatrics Department, A C Camargo Hospital, São Paulo, Brazil; 2Biological Science Department, Federal University of São Paulo, Diadema, Brazil; 3Department of Pediatrics, Pediatric Oncology Institute, GRAACC/Federal University of São Paulo, São Paulo, Brazil; 4Department of Morphology and Genetics, Federal University of São Paulo, São Paulo, Brazil; 5Department of Head and Neck Surgery, PIO XII Foundation, Barretos Cancer Hospital, Barretos, São Paulo, Brazil; 6Research Program Pediatric Oncology Program, CPNq, Instituto Nacional do Cancer, Rio de Janeiro, BrazilAbstract: Osteosarcoma (OS is the eighth most common form of childhood and adolescence cancer. Approximately 10%–20% of patients present metastatic disease at diagnosis and the 5-year overall survival remains around 70% for nonmetastatic patients and around 30% for metastatic patients. Metastatic disease at diagnosis and the necrosis grade induced by preoperative treatment are the only well-established prognostic factors for osteosarcoma. The DNA aberrant methylation is a frequent epigenetic alteration in humans and has been described as a molecular marker in different tumor types. This study evaluated the DNA aberrant methylation status of 18 genes in 34 OS samples without previous chemotherapy treatment and in four normal bone specimens and compared the methylation profile with clinicopathological characteristics of the patients. We were able to define a three-gene panel (AIM1, p14ARF, and ESR1 in which methylation was correlated with OS cases. The hypermethylation of p14ARF showed a significant association with the absence of metastases at diagnoses, while ESR1 hypermethylation was marginally associated with worse overall survival. This study demonstrated that aberrant promoter methylation is a common event

  15. 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.

  16. Survey of familial glioma and role of germline p16INK4A/p14ARF and p53 mutation

    DEFF Research Database (Denmark)

    Robertson, Lindsay B; Armstrong, Georgina N; Olver, Bianca D

    2010-01-01

    There is increasing recognition of familial propensity to glioma as a distinct clinical entity beyond a few rare syndromes; however its genetic basis is poorly understood. The role of p16(INK4A)/p14(ARF) and p53 mutations in sporadic glioma provides a strong rationale for investigating germline...... mutations in these genes as a cause of familial glioma. To survey the familial glioma phenotype and examine the contribution of germline mutation in p16(INK4A)/p14(ARF) and p53 to the disease we have analyzed a series of 101 index familial cases collected through the GLIOGENE Consortium (http......://braintumor.epigenetic.org/). There was little evidence for within family correlations for tumour histology, suggesting generic susceptibility to glial tumors. We did not detect any functional mutations in p16(INK4A) or p14(ARF). One index case with glioblastoma multiforme (GBM) diagnosed at age 54 and had a family history comprised...

  17. Predicting postoperative acute respiratory failure in critical care using nursing notes and physiological signals.

    Science.gov (United States)

    Huddar, Vijay; Rajan, Vaibhav; Bhattacharya, Sakyajit; Roy, Shourya

    2014-01-01

    Postoperative Acute Respiratory Failure (ARF) is a serious complication in critical care affecting patient morbidity and mortality. In this paper we investigate a novel approach to predicting ARF in critically ill patients. We study the use of two disparate sources of information – semi-structured text contained in nursing notes and investigative reports that are regularly recorded and the respiration rate, a physiological signal that is continuously monitored during a patient's ICU stay. Unlike previous works that retrospectively analyze complications, we exclude discharge summaries from our analysis envisaging a real time system that predicts ARF during the ICU stay. Our experiments, on more than 800 patient records from the MIMIC II database, demonstrate that text sources within the ICU contain strong signals for distinguishing between patients who are at risk for ARF from those who are not at risk. These results suggest that large scale systems using both structured and unstructured data recorded in critical care can be effectively used to predict complications, which in turn can lead to preemptive care with potentially improved outcomes, mortality rates and decreased length of stay and cost.

  18. PI3K regulates endocytosis after insulin secretion by mediating signaling crosstalk between Arf6 and Rab27a.

    Science.gov (United States)

    Yamaoka, Mami; Ando, Tomomi; Terabayashi, Takeshi; Okamoto, Mitsuhiro; Takei, Masahiro; Nishioka, Tomoki; Kaibuchi, Kozo; Matsunaga, Kohichi; Ishizaki, Ray; Izumi, Tetsuro; Niki, Ichiro; Ishizaki, Toshimasa; Kimura, Toshihide

    2016-02-01

    In secretory cells, endocytosis is coupled to exocytosis to enable proper secretion. Although endocytosis is crucial to maintain cellular homeostasis before and after secretion, knowledge about secretagogue-induced endocytosis in secretory cells is still limited. Here, we searched for proteins that interacted with the Rab27a GTPase-activating protein (GAP) EPI64 (also known as TBC1D10A) and identified the Arf6 guanine-nucleotide-exchange factor (GEF) ARNO (also known as CYTH2) in pancreatic β-cells. We found that the insulin secretagogue glucose promotes phosphatidylinositol (3,4,5)-trisphosphate (PIP3) generation through phosphoinositide 3-kinase (PI3K), thereby recruiting ARNO to the intracellular side of the plasma membrane. Peripheral ARNO promotes clathrin assembly through its GEF activity for Arf6 and regulates the early stage of endocytosis. We also found that peripheral ARNO recruits EPI64 to the same area and that the interaction requires glucose-induced endocytosis in pancreatic β-cells. Given that GTP- and GDP-bound Rab27a regulate exocytosis and the late stage of endocytosis, our results indicate that the glucose-induced activation of PI3K plays a pivotal role in exocytosis-endocytosis coupling, and that ARNO and EPI64 regulate endocytosis at distinct stages.

  19. Nonplanar ion-acoustic solitons collision in Xe+-F-- SF6- and Ar+-F-- SF6- plasmas

    Science.gov (United States)

    El-Tantawy, S. A.; Carbonaro, P.

    2016-04-01

    The solitons collision in nonplanar (cylindrical and spherical) plasmas consisting of positive ions, two different negative ions, and isothermal electrons is studied. For this purpose, the Poincaré-Lighthill-Kuo (PLK) method is used to obtain two-coupled nonplanar Korteweg-de Vries (nKdV) equations. Also, the nonplanar phase shifts are calculated. The physical parameters of two plasma experiments; namely Xe+-F-- SF6- and Ar+-F-- SF6- are used to examine the properties of the localized pulses and their phase shifts after collision. It is found that the present model gives rise to the propagation of positive and negative pulses. The effects of the total negative ions concentration, the density ratio of the second-negative ions, the temperature ratio, and the geometrical effects on the behavior of solitons collisions and their phase shifts are investigated. Furthermore, it is found that the phase shifts in the case of the Ar+-F-- SF6- plasma are much larger than those of the Xe+-F-- SF6- plasma. Also, for fixed plasma parameters, the solitons collision received the largest phase shift in spherical geometry, followed by the cylindrical and planar geometries.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  3. 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

  4. 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

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  7. 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.

  8. 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 ...

  9. 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

  10. 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

  11. 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....

  12. 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...

  13. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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

  16. 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

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

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    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. 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.

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

    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.

  1. 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

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

    Directory of Open Access Journals (Sweden)

    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

  3. 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.

  4. 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.

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

    Science.gov (United States)

    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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Antimicrobial effects of liquid anesthetic isoflurane on Candida albicans

    Directory of Open Access Journals (Sweden)

    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.

  13. Candida albicans menengitis in a newborn with classical galactosemia

    Directory of Open Access Journals (Sweden)

    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

  14. 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

  15. 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.

  16. Insights into the localization and function of the membrane trafficking regulator GNOM ARF-GEF at the Golgi apparatus in Arabidopsis.

    Science.gov (United States)

    Naramoto, Satoshi; Otegui, Marisa S; Kutsuna, Natsumaro; de Rycke, Riet; Dainobu, Tomoko; Karampelias, Michael; Fujimoto, Masaru; Feraru, Elena; Miki, Daisuke; Fukuda, Hiroo; Nakano, Akihiko; Friml, Jiří

    2014-07-01

    GNOM is one of the most characterized membrane trafficking regulators in plants, with crucial roles in development. GNOM encodes an ARF-guanine nucleotide exchange factor (ARF-GEF) that activates small GTPases of the ARF (ADP ribosylation factor) class to mediate vesicle budding at endomembranes. The crucial role of GNOM in recycling of PIN auxin transporters and other proteins to the plasma membrane was identified in studies using the ARF-GEF inhibitor brefeldin A (BFA). GNOM, the most prominent regulator of recycling in plants, has been proposed to act and localize at so far elusive recycling endosomes. Here, we report the GNOM localization in context of its cellular function in Arabidopsis thaliana. State-of-the-art imaging, pharmacological interference, and ultrastructure analysis show that GNOM predominantly localizes to Golgi apparatus. Super-resolution confocal live imaging microscopy identified GNOM and its closest homolog GNOM-like 1 at distinct subdomains on Golgi cisternae. Short-term BFA treatment stabilizes GNOM at the Golgi apparatus, whereas prolonged exposures results in GNOM translocation to trans-Golgi network (TGN)/early endosomes (EEs). Malformed TGN/EE in gnom mutants suggests a role for GNOM in maintaining TGN/EE function. Our results redefine the subcellular action of GNOM and reevaluate the identity and function of recycling endosomes in plants.

  17. ASC-J9(®) suppresses castration resistant prostate cancer progression via degrading the enzalutamide-induced androgen receptor mutant AR-F876L.

    Science.gov (United States)

    Wang, Ronghao; Lin, Wanying; Lin, Changyi; Li, Lei; Sun, Yin; Chang, Chawnshang

    2016-08-28

    Androgen deprivation therapy (ADT) with the newly developed powerful anti-androgen enzalutamide (Enz, also known as MDV3100) has promising therapeutic effects to suppress castration resistant prostate cancer (CRPC) and extending patients' lives an extra 4.8 months. However, most Enz therapy eventually fails with the development of Enz resistance. The detailed mechanisms how CRPC develops Enz resistance remain unclear and may involve multiple mechanisms. Among them, the induction of the androgen receptor (AR) mutant AR-F876L in some CRPC patients may represent one driving force that confers Enz resistance. Here, we demonstrate that the AR degradation enhancer, ASC-J9(®), not only degrades wild-type AR, but also has the ability to target AR-F876L. The consequence of suppressing AR-F876L may then abrogate AR-F876L mediated CRPC cell proliferation and metastasis. Thus, developing ASC-J9(®) as a new therapeutic approach may represent a novel therapy to better suppress CRPC that has already developed Enz resistance.

  18. Loss of p19(Arf facilitates the angiogenic switch and tumor initiation in a multi-stage cancer model via p53-dependent and independent mechanisms.

    Directory of Open Access Journals (Sweden)

    Danielle B Ulanet

    Full Text Available The Arf tumor suppressor acts as a sensor of oncogenic signals, countering aberrant proliferation in large part via activation of the p53 transcriptional program, though a number of p53-independent functions have been described. Mounting evidence suggests that, in addition to promoting tumorigenesis via disruptions in the homeostatic balance between cell proliferation and apoptosis of overt cancer cells, genetic alterations leading to tumor suppressor loss of function or oncogene gain of function can also incite tumor development via effects on the tumor microenvironment. In a transgenic mouse model of multi-stage pancreatic neuroendocrine carcinogenesis (PNET driven by inhibition of the canonical p53 and Rb tumor suppressors with SV40 large T-antigen (Tag, stochastic progression to tumors is limited in part by a requirement for initiation of an angiogenic switch. Despite inhibition of p53 by Tag in this mouse PNET model, concomitant disruption of Arf via genetic knockout resulted in a significantly accelerated pathway to tumor formation that was surprisingly not driven by alterations in tumor cell proliferation or apoptosis, but rather via earlier activation of the angiogenic switch. In the setting of a constitutional p53 gene knockout, loss of Arf also accelerated tumor development, albeit to a lesser degree. These findings demonstrate that Arf loss of function can promote tumorigenesis via facilitating angiogenesis, at least in part, through p53-independent mechanisms.

  19. OsARF16 is involved in cytokinin-mediated inhibition of phosphate transport and phosphate signaling in rice (Oryza sativa L..

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    Chenjia Shen

    Full Text Available Plant responses to phytohormone stimuli are the most important biological features for plants to survive in a complex environment. Cytokinin regulates growth and nutrient homeostasis, such as the phosphate (Pi starvation response and Pi uptake in plants. However, the mechanisms underlying how cytokinin participates in Pi uptake and Pi signaling are largely unknown. In this study, we found that OsARF16 is required for the cytokinin response and is involved in the negative regulation of Pi uptake and Pi signaling by cytokinin.The mutant osarf16 showed an obvious resistance to exogenous cytokinin treatment and the expression level of the OsARF16 gene was considerably up-regulated by cytokinin. Cytokinin (6-BA application suppressed Pi uptake and the Pi starvation response in wild-type Nipponbare (NIP and all these responses were compromised in the osarf16 mutant. Our data showed that cytokinin inhibits the transport of Pi from the roots to the shoots and that OsARF16 is involved in this process. The Pi content in the osarf16 mutant was much higher than in NIP under 6-BA treatment. The expressions of PHOSPHATE TRANSPORTER1 (PHT1 genes, phosphate (Pi starvation-induced (PSI genes and purple PAPase genes were higher in the osarf16 mutant than in NIP under cytokinin treatment.Our results revealed a new biological function for OsARF16 in the cytokinin-mediated inhibition of Pi uptake and Pi signaling in rice.

  20. 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.

  1. Somatotropinomas, but not nonfunctioning pituitary adenomas, maintain a functional apoptotic RET/Pit1/ARF/p53 pathway that is blocked by excess GDNF.

    Science.gov (United States)

    Diaz-Rodriguez, Esther; Garcia-Rendueles, Angela R; Ibáñez-Costa, Alejandro; Gutierrez-Pascual, Ester; Garcia-Lavandeira, Montserrat; Leal, Alfonso; Japon, Miguel A; Soto, Alfonso; Venegas, Eva; Tinahones, Francisco J; Garcia-Arnes, Juan A; Benito, Pedro; Angeles Galvez, Maria; Jimenez-Reina, Luis; Bernabeu, Ignacio; Dieguez, Carlos; Luque, Raul M; Castaño, Justo P; Alvarez, Clara V

    2014-11-01

    Acromegaly is caused by somatotroph cell adenomas (somatotropinomas [ACROs]), which secrete GH. Human and rodent somatotroph cells express the RET receptor. In rodents, when normal somatotrophs are deprived of the RET ligand, GDNF (Glial Cell Derived Neurotrophic Factor), RET is processed intracellularly to induce overexpression of Pit1 [Transcription factor (gene : POUF1) essential for transcription of Pituitary hormones GH, PRL and TSHb], which in turn leads to p19Arf/p53-dependent apoptosis. Our purpose was to ascertain whether human ACROs maintain the RET/Pit1/p14ARF/p53/apoptosis pathway, relative to nonfunctioning pituitary adenomas (NFPAs). Apoptosis in the absence and presence of GDNF was studied in primary cultures of 8 ACROs and 3 NFPAs. Parallel protein extracts were analyzed for expression of RET, Pit1, p19Arf, p53, and phospho-Akt. When GDNF deprived, ACRO cells, but not NFPAs, presented marked level of apoptosis that was prevented in the presence of GDNF. Apoptosis was accompanied by RET processing, Pit1 accumulation, and p14ARF and p53 induction. GDNF prevented all these effects via activation of phospho-AKT. Overexpression of human Pit1 (hPit1) directly induced p19Arf/p53 and apoptosis in a pituitary cell line. Using in silico studies, 2 CCAAT/enhancer binding protein alpha (cEBPα) consensus-binding sites were found to be 100% conserved in mouse, rat, and hPit1 promoters. Deletion of 1 cEBPα site prevented the RET-induced increase in hPit1 promoter expression. TaqMan qRT-PCR (real time RT-PCR) for RET, Pit1, Arf, TP53, GDNF, steroidogenic factor 1, and GH was performed in RNA from whole ACRO and NFPA tumors. ACRO but not NFPA adenomas express RET and Pit1. GDNF expression in the tumors was positively correlated with RET and negatively correlated with p53. In conclusion, ACROs maintain an active RET/Pit1/p14Arf/p53/apoptosis pathway that is inhibited by GDNF. Disruption of GDNF's survival function might constitute a new therapeutic route in

  2. Model-based mask data preparation (MB-MDP) for ArF and EUV mask process correction

    Science.gov (United States)

    Hagiwara, Kazuyuki; Bork, Ingo; Fujimura, Aki

    2011-05-01

    Using Model-Based Mask Data Preparation (MB-MDP) complex masks with complex sub-resolution assist features (SRAFs) can be written in practical write times with today's leading-edge production VSB machines by allowing overlapping VSB shots. This simulation-based approach reduces shot count by taking advantage of the added flexibility in being able to overlap shots. The freedom to overlap shots, it turns out, also increases mask fidelity, CDU on the mask, and CDU on the wafer by writing sub-100nm mask features more accurately, and with better dose margin. This paper describes how overlapping shots enhance mask and wafer quality for various sub-100nm features on ArF masks. In addition, this paper describes how EUV mask accuracy can be enhanced uniquely by allowing overlapping shots.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. The ArF laser for the next-generation multiple-patterning immersion lithography supporting green operations

    Science.gov (United States)

    Ishida, Keisuke; Ohta, Takeshi; Miyamoto, Hirotaka; Kumazaki, Takahito; Tsushima, Hiroaki; Kurosu, Akihiko; Matsunaga, Takashi; Mizoguchi, Hakaru

    2016-03-01

    Multiple patterning ArF immersion lithography has been expected as the promising technology to satisfy tighter leading edge device requirements. One of the most important features of the next generation lasers will be the ability to support green operations while further improving cost of ownership and performance. Especially, the dependence on rare gases, such as Neon and Helium, is becoming a critical issue for high volume manufacturing process. The new ArF excimer laser, GT64A has been developed to cope with the reduction of operational costs, the prevention against rare resource shortage and the improvement of device yield in multiple-patterning lithography. GT64A has advantages in efficiency and stability based on the field-proven injection-lock twin-chamber platform (GigaTwin platform). By the combination of GigaTwin platform and the advanced gas control algorithm, the consumption of rare gases such as Neon is reduced to a half. And newly designed Line Narrowing Module can realize completely Helium free operation. For the device yield improvement, spectral bandwidth stability is important to increase image contrast and contribute to the further reduction of CD variation. The new spectral bandwidth control algorithm and high response actuator has been developed to compensate the offset due to thermal change during the interval such as the period of wafer exchange operation. And REDeeM Cloud™, new monitoring system for managing light source performance and operations, is on-board and provides detailed light source information such as wavelength, energy, E95, etc.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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.

  18. 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...

  19. 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

  20. 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.

  1. 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...

  2. [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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  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. MicroRNA390-directed TAS3 cleavage leads to the production of tasiRNA-ARF3/4 during somatic embryogenesis in Dimocarpus longan Lour.

    Directory of Open Access Journals (Sweden)

    Yuling eLin

    2015-12-01

    Full Text Available Trans-acting short-interfering RNAs (tasiRNAs originate from TAS3 families through microRNA (miRNA 390-guided cleavage of primary transcripts and target auxin response factors (ARF3/-4, which are involved in the normal development of lateral roots and flowers in plants. However, their roles in embryo development are still unclear. Here, the pathway miR390-TAS3-ARF3/-4 was identified systematically for the first time during somatic embryo development in Dimocarpus longan. We identified the miR390 primary transcript and promoter. The promoter contained cis-acting elements responsive to stimuli such as light, salicylic acid, anaerobic induction, fungal elicitor, circadian control and heat stress. The longan TAS3 transcript, containing two miR390-binding sites, was isolated; the miR390- guided cleavage site located near the 3' end of the TAS3 transcript was verified. Eight TAS3-tasiRNAs with the 21-nucleotide phase were found among longan small RNA data, further confirming that miR390-directed TAS3 cleavage leads to the production of tasiRNA in longan. Among them, TAS3_5'D5+ and 5'D6+ tasiRNAs were highly abundant, and verified to target ARF3 and -4, implying that miR390-guided TAS3 cleavage with 21-nucleotide phase leading to the production of tasiRNA-ARF is conserved in plants. Pri-miR390 was highly expressed in friable-embryogenic callus (EC, and less expressed in incomplete compact pro-embryogenic cultures,while miR390 showed its lowest expression in EC and highest expression in torpedo-shaped embryo. DlTAS3 and DlARF4 both exhibited their lowest expressions in EC, and reached their peaks in the globular embryos stage, which were mainly inversely proportional to the expression of miR390, especially at the GE to CE stages. While DlARF3 showed little variation from the EC to torpedo-shaped embryos stages, and exhibited its lowest expression in the cotyledonary embryos stage. There was a general lack of correlation between the expressions of DlARF3

  11. 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

  12. 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

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

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    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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

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

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    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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. The H3K27me3 demethylase JMJD3 contributes to the activation of the INK4A-ARF locus in response to oncogene- and stress-induced senescence

    DEFF Research Database (Denmark)

    Agger, Karl; Cloos, Paul A C; Rudkjaer, Lise

    2009-01-01

    The tumor suppressor proteins p16INK4A and p14ARF, encoded by the INK4A-ARF locus, are key regulators of cellular senescence. The locus is epigenetically silenced by the repressive H3K27me3 mark in normally growing cells, but becomes activated in response to oncogenic stress. Here, we show...... that expression of the histone H3 Lys 27 (H3K27) demethylase JMJD3 is induced upon activation of the RAS-RAF signaling pathway. JMJD3 is recruited to the INK4A-ARF locus and contributes to the transcriptional activation of p16INK4A in human diploid fibroblasts. Additionally, inhibition of Jmjd3 expression...... in mouse embryonic fibroblasts results in suppression of p16Ink4a and p19Arf expression and in their immortalization....

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. 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...

  12. 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.

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

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    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.

  14. 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.

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

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    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

  16. 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.

  17. 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.

  18. 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.

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

    Science.gov (United States)

    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

    Science.gov (United States)

    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. 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.

  2. 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.

  3. 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.

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

    Science.gov (United States)

    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.

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

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    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.

  8. Competitive binding inhibition enzyme-linked immunosorbent assay that uses the secreted aspartyl proteinase of Candida albicans as an antigenic marker for diagnosis of disseminated candidiasis.

    Science.gov (United States)

    Morrison, Christine J; Hurst, Steven F; Reiss, Errol

    2003-09-01

    The secreted aspartyl proteinases (Saps) of Candida albicans have been implicated as virulence factors associated with adherence and tissue invasion. The potential use of proteinases as markers of invasive candidiasis led us to develop a competitive binding inhibition enzyme-linked immunosorbent assay (ELISA) to detect Sap in clinical specimens. Daily serum and urine specimens were collected from rabbits that had been immunosuppressed with cyclophosphamide and cortisone acetate and infected intravenously with 10(7) C. albicans blastoconidia. Disseminated infection was confirmed by organ culture and histopathology. Although ELISA inhibition was observed when serum specimens from these rabbits were used, more significant inhibition, which correlated with disease progression, occurred when urine specimens were used. Urine collected as early as 1 day after infection resulted in significant ELISA inhibition (mean inhibition +/- standard error [SE] compared with preinfection control urine, 15.7% +/- 2.7% [P ELISA results. Dissemination to the kidney and spleen occurred in one rabbit challenged by intragastric inoculation, and urine from this rabbit demonstrated significant inhibition in the ELISA (mean inhibition +/- SE by day 3 after infection, 32.9% +/- 2.7% [P test sensitivity was 83%, the specificity was 92%, the positive predictive value was 84%, the negative predictive value was 91%, and the efficiency was 89% (166 urine samples from 33 rabbits tested). The specificity, positive predictive value, and efficiency could be increased to 97, 95, and 92%, respectively, if at least two positive test results were required for a true positive designation. The ELISA was sensitive and specific for the detection of Sap in urine specimens from rabbits with disseminated C. albicans infection, discriminated between colonization and invasive disease, reflected disease progression and severity, and has the potential to be a noninvasive means to diagnose disseminated candidiasis.

  9. Lime pretreatment of sugar beet pulp and evaluation of synergy between ArfA, ManA and XynA from Clostridium cellulovorans on the pretreated substrate

    OpenAIRE

    Dredge, Roselyn; Radloff, Sarah E.; Van Dyk, J. Susan; Brett I. Pletschke

    2011-01-01

    Sugar beet pulp (SBP) is a waste product from the sugar beet industry and could be used as a potential biomass feedstock for second generation biofuel technology. Pretreatment of SBP with ‘slake lime’ (calcium hydroxide) was investigated using a 23 factorial design and the factors examined included lime loading, temperature and time. The pretreatment was evaluated for its ability to enhance enzymatic degradation using a combination of three hemicellulases, namely ArfA (an arabinofuranosidase)...

  10. Reversible bleb formation in mast cells stimulated with antigen is Ca2+/calmodulin-dependent and bleb size is regulated by ARF6.

    Science.gov (United States)

    Yanase, Yuhki; Carvou, Nicolas; Frohman, Michael A; Cockcroft, Shamshad

    2009-12-14

    Mast cells stimulated with antigen undergo extensive changes in their cytoskeleton. In the present study, we assess the impact of actin-modifying drugs and report that, in the presence of cytochalasin D, mast cells stop membrane ruffling, but instead bleb. Bleb formation is reversible following washout of cytochalasin D and occurs in an actin-polymerization-dependent manner. Bleb formation is inhibited by expression of constitutively active ezrin-T567D. Blebbing is also inhibited by blebbistatin, a myosin II inhibitor, implying myosin II activation in the process. We used a selection of inhibitors and observed that myosin II activation is dependent mainly on Ca2+-calmodulin, with only a small contribution from Rho kinase. The signalling pathways stimulated by antigen include PLC (phospholipase C) and PLD (phospholipase D). Bleb formation was dependent on activation of PLC, but not PLD. Primary alcohols, used previously as a means to reduce PLD-derived phosphatidic acid, were potent inhibitors of membrane blebbing, but a more selective inhibitor of PLD, FIPI (5-fluoro-2-indolyl des-chlorohalopemide), was without effect. FIPI also did not inhibit membrane ruffling or degranulation of mast cells, indicating that inhibition by primary alcohols works through an unidentified mechanism rather than via diversion of PLD activity as assumed. We also examined the requirement for ARF6 (ADP-ribosylation factor 6) and observed that its expression led to an increase in bleb size and a further increase was observed with the dominant-active mutant, ARF6-Q67L. Since ARF6-T27N had no effect on bleb size, we conclude that ARF6 needs to be active to regulate the size of the blebs.

  11. ARF-B2: A Protein Complex that Specifically Binds to Part of the Anaerobic Response Element of Maize Adh 11

    Science.gov (United States)

    Ferl, Robert J.

    1990-01-01

    Crude whole cell extracts from maize (Zea mays L.) suspension cells were examined for DNA binding proteins that specifically interact with a portion of the maize Adh 1 promoter that was previously shown to be in contact with a trans-acting factor in vivo. A 17 base pair, double-stranded oligonucleotide probe was constructed that centered around a strong in vivo dimethylsulfate footprint (B2) that coincides with part of the anaerobic response element (ARE). Gel retardation assays were used to characterize a major, specific DNA binding protein activity found in the crude extracts. The activity is present in both aerobic and hypoxically treated cultures and has been designated ARF-B2 (ARE binding factor). ARF-B2 appears to be a multicomponent complex, with a 54 kilodalton subunit termed ARF-B2α in primary contact with the target DNA. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:16667563

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    OpenAIRE

    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...

  15. 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.

  16. 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.

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. The Endosome Localized Arf-GAP AGAP1 Modulates Dendritic Spine Morphology Downstream of the Neurodevelopmental Disorder Factor Dysbindin

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    Miranda Arnold

    2016-09-01

    Full Text Available AGAP1 is an Arf1 GTPase activating protein that interacts with the vesicle-associated protein complexes adaptor protein 3 (AP-3 and Biogenesis of Lysosome Related Organelles Complex-1 (BLOC-1. Overexpression of AGAP1 in non-neuronal cells results in an accumulation of endosomal cargoes, which suggests a role in endosome-dependent traffic. In addition, AGAP1 is a candidate susceptibility gene for two neurodevelopmental disorders, autism spectrum disorder (ASD and schizophrenia (SZ; yet its localization and function in neurons have not been described. Here, we describe that AGAP1 localizes to axons, dendrites, dendritic spines, and synapses, colocalizing preferentially with markers of early and recycling endosomes. Functional studies reveal overexpression and down-regulation of AGAP1 affects both neuronal endosomal trafficking and dendritic spine morphology, supporting a role for AGAP1 in the recycling endosomal trafficking involved in their morphogenesis. Finally, we determined the sensitivity of AGAP1 expression to mutations in the DTNBP1 gene, which is associated with neurodevelopmental disorder, and found that AGAP1 mRNA and protein levels are selectively reduced in the null allele of the mouse orthologue of DTNBP1. We postulate that endosomal trafficking contributes to the pathogenesis of neurodevelopmental disorders affecting dendritic spine morphology, and thus excitatory synapse structure and function.

  20. The Endosome Localized Arf-GAP AGAP1 Modulates Dendritic Spine Morphology Downstream of the Neurodevelopmental Disorder Factor Dysbindin

    Science.gov (United States)

    Arnold, Miranda; Cross, Rebecca; Singleton, Kaela S.; Zlatic, Stephanie; Chapleau, Christopher; Mullin, Ariana P.; Rolle, Isaiah; Moore, Carlene C.; Theibert, Anne; Pozzo-Miller, Lucas; Faundez, Victor; Larimore, Jennifer

    2016-01-01

    AGAP1 is an Arf1 GTPase activating protein that interacts with the vesicle-associated protein complexes adaptor protein 3 (AP-3) and Biogenesis of Lysosome Related Organelles Complex-1 (BLOC-1). Overexpression of AGAP1 in non-neuronal cells results in an accumulation of endosomal cargoes, which suggests a role in endosome-dependent traffic. In addition, AGAP1 is a candidate susceptibility gene for two neurodevelopmental disorders, autism spectrum disorder (ASD) and schizophrenia (SZ); yet its localization and function in neurons have not been described. Here, we describe that AGAP1 localizes to axons, dendrites, dendritic spines and synapses, colocalizing preferentially with markers of early and recycling endosomes. Functional studies reveal overexpression and down-regulation of AGAP1 affects both neuronal endosomal trafficking and dendritic spine morphology, supporting a role for AGAP1 in the recycling endosomal trafficking involved in their morphogenesis. Finally, we determined the sensitivity of AGAP1 expression to mutations in the DTNBP1 gene, which is associated with neurodevelopmental disorder, and found that AGAP1 mRNA and protein levels are selectively reduced in the null allele of the mouse ortholog of DTNBP1. We postulate that endosomal trafficking contributes to the pathogenesis of neurodevelopmental disorders affecting dendritic spine morphology, and thus excitatory synapse structure and function. PMID:27713690

  1. The influence of ArF excimer laser micromachining on physicochemical properties of bioresorbable poly(L-lactide)

    Science.gov (United States)

    Stepak, Bogusz D.; Antończak, Arkadiusz J.; Szustakiewicz, Konrad; Pezowicz, Celina; Abramski, Krzysztof M.

    2016-03-01

    The main advantage of laser processing is a non-contact character of material removal and high precision attainable thanks to low laser beam dimensions. This technique enables forming a complex, submillimeter geometrical shapes such as vascular stents which cannot be manufactured using traditional techniques e.g. injection moulding or mechanical treatment. In the domain of nanosecond laser sources, an ArF excimer laser appears as a good candidate for laser micromachining of bioresorbable polymers such as poly(L-lactide). Due to long pulse duration, however, there is a risk of heat diffusion and accumulation in the material. In addition, due to short wavelength (193 nm) photochemical process can modify the chemical composition of ablated surfaces. The motivation for this research was to evaluate the influence of laser micromachining on physicochemical properties of poly(L-lactide). We performed calorimetric analysis of laser machined samples by using differential scanning calorimetry (DSC). It allowed us to find the optimal process parameters for heat affected zone (HAZ) reduction. The chemical composition of the ablated surface was investigated by FTIR in attenuated total reflectance (ATR) mode.

  2. ARF6-regulated endocytosis of growth factor receptors links cadherin-based adhesion to canonical Wnt signaling in epithelia.

    Science.gov (United States)

    Pellon-Cardenas, Oscar; Clancy, James; Uwimpuhwe, Henriette; D'Souza-Schorey, Crislyn

    2013-08-01

    Wnt signaling has an essential role in embryonic development as well as stem/progenitor cell renewal, and its aberrant activation is implicated in many diseases, including several cancers. β-Catenin is a critical component of Wnt-mediated transcriptional activation. Here we show that ARF6 activation during canonical Wnt signaling promotes the intracellular accumulation of β-catenin via a mechanism that involves the endocytosis of growth factor receptors and robust activation of extracellular signal-regulated kinase (ERK). ERK promotes casein kinase 2-mediated phosphorylation of α-catenin, leading to destabilization of the adherens junctions and a subsequent increase in cytoplasmic pools of active β-catenin and E-cadherin. ERK also phosphorylates LRP6 to amplify the Wnt transduction pathway. The aforementioned Wnt-ERK signaling pathway initiates lumen filling of epithelial cysts by promoting cell proliferation in three-dimensional cell cultures. This study elucidates a mechanism responsible for the switch in β-catenin functions in cell adhesion at the adherens junctions and Wnt-induced nuclear signaling.

  3. Efficiency enhancement using ArF laser induced micro/nanostructures on the polymeric layer of solar cell

    Science.gov (United States)

    Parvin, P.; Reyhani, A.; Mehrabi, M.; Refahizadeh, M.; Mortazavi, S. Z.; Ranjbar, A.

    2017-02-01

    Here, the solar cell surface is irradiated with ArF excimer laser at 193 nm. This process forms regular micro/nanostructures on the samples, most likely due to the surface resonance phenomena. Laser induced surface rippling in the form of the conical micro/nanostructures or micro/nano-pillars are strongly dependent on the energy dose which induces a great number of micro/nano cavities on the surface. Despite the reflection events are taken into account as the major source of the optical losses, however the laser induced self-micro/nano structuring significantly reduces the spectral reflectivity. It leads to enhance the efficiency of solar cell accordingly. The effect of laser fluence is also investigated as to several forms of the micro/nanostructures are created at various UV doses. Finally, the electrical characterization is carried out based on the current-voltage plots. The surface morphology is analyzed using SEM and the spectral reflectivity is measured by the spectrophotometry, indicating that the current density rises due to the light trapping in micro/nano-cavities.

  4. 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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  7. Prevalence of Trichomonas vaginalis and Candida albicans among Brazilian Women of Reproductive Age

    Science.gov (United States)

    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

  8. 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.

  9. 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.

  10. 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.

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

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    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

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

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    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.

  13. 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.

  14. HPV阴性的宫颈癌和癌前病变中p14ARF蛋白表达及其临床意义%Expression and clinical significance of p14ARF protein in HPV - negative patients with cervical cancer and cervical precancerous lesion

    Institute of Scientific and Technical Information of China (English)

    尹香花; 苏悦; 隋玉梅; 成艳

    2011-01-01

    Objective:To explore the relationship between pl4ARF protein, matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and early diagnosis, invasion and metastasis of cervical cancer by detecting their expression levels in cervical canc-er and cervical intraepithelial neoplasia (CIN) of human papillomavirus ( HPV ) - negative patients. Methods: 30 HPV - negative patients with chronic cervicitis, 35 HPV - negative patients with CIN and 35 HPV - negative patients with cervical invasive cancer were selected as study ob-jects by PCR. Immunohistochemical SP staining was used to detect the expression level of pl4ARF protein, clinicopathological characteristics and the correlation with the depth of invasion and lymph node metastasis. Results :P14ARF protein specifically expressed in the nuclei and cyto-plasm of CIN and cervical cancer cells, and it never expressed in normal squamous epithelium and glandular epithelium, there was no correla-tion between P14ARF protein expression and clinical stages, while it was related to the degree of differentiation and lymph node metastasis. Conclusion: pl4ARF protein detection can be used as an index for early diagnosis of cervical cancer among HPV - negative patients, which also can be used as an index to predict the potential of invasion and metastasis of cervical cancer and clinical prognosis.%目的:通过检测人乳头状瘤病毒(HPV)感染阴性的官颈癌和宫颈上皮内瘤变中p14ARF和基质金属蛋白酶MMPs及其抑制物TIMPs的表达,探讨其与官颈癌早期诊断、侵袭转移的关系.方法:以PCR方法筛查HPV阴性的慢性官颈炎30例、官颈上皮内瘤变(CIN) 35例及官颈浸润癌35例作为研究对象,采用SP染色法检测p14ARF蛋白在其中的表达,分析p14ARF蛋白在官颈癌组织中的表达、临床病理特征及其与浸润深度、淋巴结转移的相关性.结果:p14ARF蛋白特异性表达在HPV阴性的CIN病变、宫颈癌细胞核及胞质中,在

  15. 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.

  16. 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.

  17. Dodonaea viscosa var. angustifolia Inhibits Germ Tube and Biofilm Formation by C. albicans

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    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.

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

    Science.gov (United States)

    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.

  19. 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.

  20. 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.

  1. 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.

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

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    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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  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. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Quantitative assessment of S. mutans and C. albicans in patients with Haas and Hyrax expanders

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    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.

  14. 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.

  15. 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.

  16. 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.

  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. 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.

  19. 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.

  20. Antifungal Activity of Coumarin from Ageratum conyzoides L. Leaves on Candida albicans cells

    Directory of Open Access Journals (Sweden)

    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.

  1. 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....

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Human antimicrobial peptide LL-37 inhibits adhesion of Candida albicans by interacting with yeast cell-wall carbohydrates.

    Directory of Open Access Journals (Sweden)

    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.

  7. 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,

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. Hsp90 governs echinocandin resistance in the pathogenic yeast Candida albicans via calcineurin.

    Directory of Open Access Journals (Sweden)

    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

  20. Divergent responses of different endothelial cell types to infection with Candida albicans and Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    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.

  1. Intestinal colonization by Candida albicans alters inflammatory responses in Bruton's tyrosine kinase-deficient mice.

    Directory of Open Access Journals (Sweden)

    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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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....

  8. Molecular analysis of the Ink4a/Rb1-Arf/Tp53 pathways in radon-induced rat lung tumors

    Energy Technology Data Exchange (ETDEWEB)

    Bastide, K.; Guilly, M.N.; Lectard, B.; Levalois, C.; Chevillard, S. [CEA, DSV, IRCM, SREIT, Laboratoire de Cancerologie Experimentale, BP6, Fontenay-aux-Roses Cedex F-92265 (France); Bernaudin, J.F. [Service d' Histologie-Biologie Tumorale, Unite Propre de Recherche de l' Enseignement Superieur EA 3499, Universite Paris 6, Hopital Tenon, Paris F-75020 (France); Joubert, Ch. [CEA, DSV, I2BM, MIRCEN, Laboratoire de Biologie Appliquee, BP6, Fontenay-aux-Roses Cedex F-92265 (France); Malfoy, B. [Institut Curie, Centre de Recherche, Paris F-75248 (France); CNRS, UMR 7147, Paris F-75248 (France); Universite Paris VI, Paris F-75248 (France)

    2009-07-01

    Inhalation of radon is closely associated with an increased risk of lung cancers. While the involvement of Ink4a in lung tumor development has been widely described, the tumor suppressor gene has not been studied in radon-induced lung tumors. In this study, loss of heterozygosity (LOH) analysis of the Cdkn2a locus, common to the Ink4a and Arf genes, was performed on 33 radon-induced rat lung tumors and showed a DNA loss in 50% of cases. The analysis of p16Ink4a protein expression by immunohistochemistry revealed that 50% of the tumors were negative for this protein. Looking for the origin of this lack of expression, we observed a low frequency of homozygous deletion (6%), a lack of mutation, an absence of correlation between promoter methylation and Ink4a mRNA expression and no correlation between LOH and protein expression. However, a tendency for an inverse correlation between p16Ink4a and pRb protein expression was observed. The expressions of p19Arf, Mmd2 and Mdm4 were not deregulated and only 14% of the tumors were mutated for Tp53. These results indicated that Ink4a/Cdk4/Rb1 pathway deregulation, more than Arf/Mdm2/Tp53 pathway, has a major role in the development of these tumors through p16Ink4a deregulation. However, all known mechanisms of inactivation of the pathway do not play a recurrent role in these tumors and the actual origin of the lack of p16Ink4a protein expression remains to be established. (author)

  9. Endogenous target mimics down-regulate miR160 mediation of ARF10, -16 and -17 cleavage during somatic embryogenesis in Dimocarpus longan Lour.

    Directory of Open Access Journals (Sweden)

    yuling elin

    2015-11-01

    Full Text Available MicroRNA160 plays a critical role in plant development by negatively regulating the auxin response factors ARF10, -16 and -17. However, the ways in which miR160 expression is regulated at the transcriptional level, and how miR160 interacts with its targets during plant embryo development, remain unknown. Here, we studied the regulatory relationships among endogenous target mimics (eTMs, and miR160 and its targets, and their involvement in hormone signaling and somatic embryogenesis (SE in Dimocarpus longan. We identified miR160 family members and isolated the miR160 precursor, primary transcript, and promoter. The promoter contained cis-acting elements responsive to stimuli such as light, abscisic acid, salicylic acid and heat stress. The pri-miR160 was down-regulated in response to salicylic acid but up-regulated by gibberellic acid, ethylene, and methyl jasmonate treatment, suggesting that pri-miR160 was associated with hormone transduction. Dlo-miR160a, -a* and -d* reached expression peaks in torpedo-shaped embryos, globular embryos and cotyledonary embryos, respectively, but were barely detectable in embryogenic callus. This suggests that they have expression-related and functional diversity, especially during the middle and later developmental stages of SE. Four potential eTMs for miR160 were identified. Two of them, glucan endo-1,3-beta- glucosidase-like protein 2-like and calpain-type cysteine protease DEK1, were confirmed to control the corresponding dlo-miR160a* expression level. This suggests that they may function to abolish the binding between dlo-miR160a* and its targets. These two eTMs also participated in auxin and ABA signal transduction. DlARF10, -16, and -17 targeting by dlo-miR160a was confirmed; their expression levels were higher in friable-embryogenic callus and incomplete compact pro-embryogenic cultures and responded to 2,4-D, suggesting they may play a major role in the early stages of longan SE dependent on 2,4-D. The e

  10. Promiscuous and specific phospholipid binding by domains in ZAC, a membrane-associated Arabidopsis protein with an ARF GAP zinc finger and a C2 domain

    DEFF Research Database (Denmark)

    Jensen, R B; Lykke-Andersen, K; Frandsen, G I

    2000-01-01

    containing the ZAC-C2 domain bind anionic phospholipids non-specifically, with some variance in Ca2+ and salt dependence. Similar assays demonstrated specific affinity of the ZAC N-terminal region (residues 1-174) for phosphatidylinositol 3-monophosphate (PI-3-P). Binding was dependent in part on an intact...... zinc finger motif, but proteins containing only the zinc finger domain (residues 1-105) did not bind PI-3-P. Recombinant ZAC possessed GTPase-activating activity on Arabidopsis ARF proteins. These data identify a novel PI-3-P-binding protein region and thereby provide evidence...

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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 effects of 6 strains of lactobacilli and their main culture metabolites on the morphogenesis of Candida albicans (C. albicans) so as to screen medicinal strains as antifungal agents. Methods: Spent culture supernatant (SCS) at different culture time points, live lactobacilli, heatkilled bacteria and bacterial short-chain fatty acids (SCFA) with different molarities were incubated with C. albicans respectively. Crystal violet-based germ tube assay was used to detect the germination of C. albicans and the inhibitory efficiency of each addition was tested by germination rate. Results: SCS of lactobacillus spp. decreased the germination significantly and live bacteria of L. rhamnosus. GG, L. acidophilus L050103-12 as well as L. johnsonii JCM1022 could partially inhibit the conversion, however, all the heatkilled bacteria failed to control the germ tube formation. In addition, only butyric acid blocked the conversion of yeast to hypha among all the SCFA. Conclusion: The excellent fungistasis activities make L.rhamnosus. GG, L. acidophilus L050103-12 and L. johnsonii JCM1022 potential strains as antifungal drugs and the inhibition seems to have direct correlation to the metabolites.

  2. Host responses to Candida albicans: Th17 cells and mucosal candidiasis

    OpenAIRE

    Conti, Heather R.; Gaffen, Sarah L.

    2010-01-01

    Candida albicans causes mucosal and disseminated candidiasis, which represent serious problems for the rapidly expanding immunocompromised population. Until recently, Th1-mediated immunity was thought to confer the primary protection, particularly for oral candidiasis. However, emerging data indicate that the newly-defined Th17 compartment appears to play the predominant role in mucosal candidiasis.

  3. Prevalence of non-albican candida infection in Maharashtrian women with leucorrhea

    Directory of Open Access Journals (Sweden)

    Seema M Bankar

    2012-01-01

    Full Text Available Background: Candida is the most common agent causing leucorrhea affecting the women of all strata. It is becoming difficult to completely eradicate the infection mainly due to recurrence caused by non-albican species of Candida. Most of the non-albican species of Candida are resistant to commonly used antifungal agent - azole. Therefore, studying the prevalence of Candida species in vaginal secretion is of great significance. Objective: To study the prevalence of different species of Candida and the efficiency of different Candida detection methods in women from low socio-economic setup of Miraj and Sangli, Maharashtra, India. Materials and Methods: The study was conducted on 150 patients with specific complaints of leucorrhea. In the control group, 50 asymptomatic women were included for comparison. Results: In 33% of the women the leucorrhea was due to Candida infection with highest incidence in women of sexually active age (20-40 years. Sabouraud′s culture was the most efficient method (100% efficiency to detect the Candida compared to wet mount, KOH and gram stain method. Candida albicans was the most common strain identified and Candida krusei was the least common one. Conclusion: Candida infection is the commonest reason for leucorrhea and non-albican candida species significantly contribute to candidiasis in women of Miraj and Sangli.

  4. 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.

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

    Science.gov (United States)

    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

  6. AKTIVITAS ANTIFUNGI EKSTRAK DAUN BELUNTAS, JAWER KOTOK, DAN SIRIH SERTA KOMBINASINYA TERHADAP Candida albicans

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    Umi Yuniarni

    2016-05-01

    Full Text Available Piper betle, Coleus scutellarioides and Pluchea indica have been used empirically to overcome vaginal discharge and scientifically proven to inhibit the growth of Candida albicans. The goal of this research was to search for a combined extract with effective antimicrobial activity against Candida albicans. Single extract,combination of two and three extracts evaluated antimicrobial activity against Candida albicans using agar diffusion method. Inhibitory effect of Piper betle showed the greatest activity against Candida albicans compared to other single extract. Combination of Piper betle and Pluchea indica (26.57±0.56 mm gave greater inhibition than two other combination extracts (Piper betle and Coleus scutellarioides (25.17±0.96 mm; Coleus scutellarioides and Pluchea indica (22.73±0.95 mm.The combination of Piper betle, Pluchea indica and Coleus scutellarioides gave inhibition of 27.53±1.10 mm. extracts did not give a better diameter compared to the betle extract.

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

    Science.gov (United States)

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

    2011-12-01

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

  8. Streptococcus mutans Competence-Stimulating Peptide Inhibits Candida albicans Hypha Formation

    NARCIS (Netherlands)

    Jarosz, Lucja M.; Deng, Dong Mei; van der Mei, Henny C.; Crielaard, Wim; Krom, Bastiaan P.

    2009-01-01

    The oral cavity is colonized by microorganisms growing in biofilms in which interspecies interactions take place. Streptococcus mutans grows in biofilms on enamel surfaces and is considered one of the main etiological agents of human dental caries. Candida albicans is also commonly found in the huma

  9. Antimicrobial effects of Piper hispidum extract, fractions and chalcones against Candida albicans and Staphylococcus aureus.

    Science.gov (United States)

    Costa, G M; Endo, E H; Cortez, D A G; Nakamura, T U; Nakamura, C V; Dias Filho, B P

    2016-09-01

    Three chalcones, 2'-hydroxy-4,4',6'-trimethoxychalcone, 2'-hydroxy-4,4',6'-tetramethoxychalcone, and 3,2'-dihydroxy-4,4',6'-trimethoxychalcone, were isolated from the leaves of Piper hispidum in a bioguided fractionation of crude extract. The antimicrobial activity of crude extract of P. hispidum leaves was determined against bacteria Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus and yeasts Candida albicans, C. parapsilosis and C. tropicalis. Fractions and chalcones were tested against C. albicans and S. aureus. The checkerboard assay was performed to assess synergic interactions between extract and antifungal drugs, and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction assay was used to evaluate anti-biofilm effects of extract. The extract was active against yeasts, S. aureus and B. subtilis with MIC values between 15.6 and 62.5μg/mL. Synergistic effects of extract associated with fluconazole and nystatin were observed against C. albicans, with fractional inhibitory concentration indices of 0.37 and 0.24, respectively. The extract was also effective against C. albicans and S. aureus biofilm cells at concentrations of 62.5 and 200μg/mL, respectively. Thus, P. hispidum may be a possible source of bioactive substances with antimicrobial properties.

  10. 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.

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

    Science.gov (United States)

    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.

  12. The Inflammatory response induced by aspartic proteases of Candida albicans is independent of proteolytic activity.

    NARCIS (Netherlands)

    Pietrella, D.; Rachini, A.; Pandey, N.; Schild, L.; Netea, M.G.; Bistoni, F.; Hube, B.; Vecchiarelli, A.

    2010-01-01

    The secretion of aspartic proteases (Saps) has long been recognized as a virulence-associated trait of the pathogenic yeast Candida albicans. In this study, we report that different recombinant Saps, including Sap1, Sap2, Sap3, and Sap6, have differing abilities to induce secretion of proinflammator

  13. Antifungal properties of Foeniculum vulgare, Carum carvi and Eucalyptus sp. essential oils against Candida albicans strains

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    Skrobonja Jelica M.

    2013-01-01

    Full Text Available Aromatic plants are among the most important sources of biologically active secondary metabolites, with high antimicrobal potential. This study was carried out to examine in vitro antifungal activity of Foeniculum vulgare (Apiaceae, Carum carvi (Apiaceae and Eucalyptus sp.(Myrtaceae essential oils against three Candida albicans strains of different origin (laboratory-CAL, human pulmonary-CAH and ATCC10231-CAR. The essential oils were screened on C. albicans using disc and well-diffusion and microdilution method, and compared to Nystatine and Fluconazole as standard anti-mycotics. The activity of tested oils was expressed by inhibition zone diameter (mm, minimum inhibitory concentration (MIC and minimum fungicidal concentration (MFC (mg/ml. The results indicated that studied essential oils show antifungal activity against all three isolates of C. albicans. It was observed that each oil exhibits different degree of antifungal activity depending on the oil concentration applied as well as on analyzed strain of C. albicans. Carum carvi demonstrated the strongest antifungal effect to all tested strains, showing the lowest MIC values (0.03mg/ml for CAL, 0.06mg/ml for CAH, and 0.11mg/ml for CAR, respectively. Eucalyptus sp. exhibited the lowest antifungal activity, with MIC values ranging from 0.11 mg/ml for CAL to 0.45 mg/ml for both CAH and CAR. [Projekat Ministarstva nauke Republike Srbije, br. 172058

  14. A Concise Synthesis of Antigenic Factor 4 Existing in Candida albicans

    Institute of Scientific and Technical Information of China (English)

    ZHU,Yu-Liang(朱玉亮); CHEN,Lang-Qiu(陈朗秋); KONG,Fan-Zuo(孔繁祚)

    2001-01-01

    A concise synthesis of α-Man12-α-Man1→3-(α-Man1→6)-α-Man12-α-Man12-a-Man12-Man,the antigenic factot 4 existing in Candida albicans,was achieved via TMSOTf promoted condensation of the corresponding acylated tetrasac charide donor with the trisaccharide acceptor.``

  15. Application of surface plasmon resonance biosensor for the detection of Candida albicans

    Science.gov (United States)

    Yodmongkol, Sirasa; Thaweboon, Sroisiri; Thaweboon, Boonyanit; Puttharugsa, Chokchai; Sutapun, Boonsong; Amarit, Ratthasart; Somboonkaew, Armote; Srikhirin, Toemsak

    2016-02-01

    In this study, surface plasmon resonance imaging (SPR imaging) was developed for the detection of Candida albicans which is a causal agent of oral infection. The detection was based on the sandwich assay. The capture antibody was covalently immobilized on the mixed self assemble monolayers (SAMs). The ratio of mixed SAMs between 11-mercaptoundecanoic acid and 3-mercaptopropanol was varied to find the optimal ratio for use as a sensor surface. The results showed that the suitable surface for C. albicans detection was SAM of carboxylic (mixed SAMs 1:0), even though mixed SAMs 1:40 had a high detection signal in comparison to mixed SAMs 1:0, but the non-specific signal was higher. The detection limit was 107 cells/ml for direct detection, and was increased to 106 cells/ml with sandwich antibody. The use of polyclonal C. albicans antibody as capture and sandwich antibody showed good selectivity against the relevant oral bacteria including Escherichia coli, Streptococcus mutan, Staphylococcus aureus, β-streptococci, and Lactobacillus casei. SPR platform in this study could detect C. albicans from the mixed microbial suspension without requirement of skillful technician. This SPR imaging biosensor could be applied for Candida identification after cultivation.

  16. Antifungal susceptibility analysis of berberine, baicalin, eugenol and curcumin on Candida albicans

    Institute of Scientific and Technical Information of China (English)

    Wu Jianhua; Wen Hai

    2009-01-01

    Objective: To analyze the antifungal effects of Chinese herb monomers, i.e. berberine, baicalin, eugenol and curcumin, on Candida albicans. Methods: After Candida albicans strain Y01-09 was incubated for 48 h in YEPD broth which contained different concentrations of Chinese herb components, the cell cycle, fluorescent intensity and the size of cell volume were detected by flow cytometry. Results: The 4 Chinese herb monomers could affect the cell cycle of Candida albicans in different ranges. The ratio of cells in S-G2-M period decreased as the agents concentration increased, indicating that the cell division was inhibited. The fluorescent intensity of Candida albicans cells became weaker after being incubated, which reflected the loss of DNA fragments. The higher the concentration was, the weaker the fluorescent intensity became. The cell size, cell diopter and particle size changed much as the agents concentration increased. Conclusion: Chinese herb monomers play the antifungal role in inhibiting cell division. FCM could be used to determine the susceptibility of antifungal agents.

  17. 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…

  18. Multilocus sequence typing confirms synonymy but highlights differences between Candida albicans and Candida stellatoidea.

    NARCIS (Netherlands)

    Jacobsen, M.D.; Boekhout, T.; Odds, F.C.

    2008-01-01

    We used multi-locus sequence typing (MLST) to investigate 35 yeast isolates representing the two genome-sequenced strains plus the type strain of Candida albicans, four isolates originally identified as Candida stellatoidea type I and 28 representing type strains of other species now regarded as syn

  19. Effect of ethanolic extract of Ecballium elaterium against Staphylococcus aureus and Candida albicans

    Institute of Scientific and Technical Information of China (English)

    Ghaleb Adwan; Yousef Salameh; Kamel Adwan

    2011-01-01

    To evaluate the antimicrobial activity of ethanolic extract of Ecballium elaterium (E.elaterium) fruits alone against Staphylococcus aureus (S. aureus) strains and Candida albicans (C. albicans) strains, or in combination with penicillin against Staphylococcus areus strains. Methods: Evaluation of the antimicrobial activity or synergy interaction was carried out using microdilution method. Results: The results showed that ethanolic extract of E. elaterium fruits has antimicrobial activity against methicillin resistant S. aureus (MRSA), methicillin sensitive S.aureus (MSSA) and C. albicans. This extract showed a significant decrease in minimum inhibitory concentrations (MIC) of penicillin against both MRSA and MSSA strains. Fractional inhibitory concentration index (FIC) between penicillin and ethanolic extract of E. elaterium fruits against these test strains was less than 0.5. Conclusions: This study suggests that ethanolic extract of E. elaterium fruits has antimicrobial activity against S. aureus and C. albicans and there is a possibility of concurrent use of penicillin and E. elaterium extract in combination in the treatment of infections caused by MRSA and MSSA strains. A wider study is needed to identify the effective components, the mode of action and the possible toxic effect in vivo of these ingredients.

  20. Induction of the immune response suppression in mice inoculated with Candida albicans.

    Science.gov (United States)

    Valdez, J C; Mesón, D E; Sirena, A; de Petrino, S F; Eugenia, M; de Jorrat, B B; de Valdex, M G

    1986-03-01

    There is a controversy in respect to the immunological response (humoral or cellular) concerning the defense against Candida albicans. Candidosis would induce sub-populations of suppressor cells in the host cell-immune response. This report tries to show the effect of different doses of C. albicans (alive or heat-killed) on the expression of cell-mediated and humoral immunity. The effect upon cell immunity was determined by inoculating different lots of singeneic mice, doses of varied concentration of C. albicans and checking for delayed-type hipersensitivity (D.T.H.). D.T.H. was also controlled in syngeneic normal mice which had previously been injected with inoculated mice spleen cells. Humoral immunity was assayed by measuring the induced blastogenesis by Pokeweed Mitogen on spleen mononuclear cells with different doses of C. albicans. Results obtained show that the different doses gave origin to: Suppression of humoral and cell response (10(8) alive); Suppression of only humoral response (10(6) alive); Suppression of cell response and increase of humoral response (10(9) dead); Increase of both responses (10(8) dead).

  1. Biofilm formation and Candida albicans morphology on the surface of denture base materials.

    Science.gov (United States)

    Susewind, Sabine; Lang, Reinhold; Hahnel, Sebastian

    2015-12-01

    Fungal biofilms may contribute to the occurrence of denture stomatitis. The objective of the study was to investigate the biofilm formation and morphology of Candida albicans in biofilms on the surface of denture base materials. Specimens were prepared from different denture base materials. After determination of surface properties and salivary pellicle formation, mono- and multispecies biofilm formation including Candida albicans ATCC 10231 was initiated. Relative amounts of adherent cells were determined after 20, 44, 68 and 188 h; C. albicans morphology was analysed employing selective fluorescence microscopic analysis. Significant differences were identified in the relative amount of cells adherent to the denture base materials. Highest blastospore/hyphae index suggesting an increased percentage of hyphae was observed in mono- and multispecies biofilms on the soft denture liner, which did not necessarily respond to the highest relative amount of adherent cells. For both biofilm models, lowest relative amount of adherent cells was identified on the methacrylate-based denture base material, which did not necessarily relate to a significantly lower blastospore/hyphae index. The results indicate that there are significant differences in both biofilm formation as well as the morphology of C. albicans cells in biofilms on the surface of different denture base materials.

  2. In vitro effects of Salvia officinalis L. essential oil on Candida albicans

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    Tularat Sookto

    2013-05-01

    Conclusions: S. officinalis L. essential oil exhibited anticandidal activities against C. albicans and had inhibitory effects on the adhesion of the cel