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  1. Candida albicans morphology and dendritic cell subsets determine T helper cell differentiation

    OpenAIRE

    Kashem, Sakeen W.; Igyarto, Botond Z.; Gerami-Nejad, Maryam; Kumamoto, Yosuke; Mohammed, Javed A.; Jarrett, Elizabeth; Drummond, Rebecca A.; Zurawski, Sandra M.; Zurawski, Gerard; Berman, Judith; Iwasaki, Akiko; Brown, Gordon D.; Kaplan, Daniel H.

    2015-01-01

    Candida albicans is a dimorphic fungus responsible for chronic mucocutaneous and systemic infections. Mucocutaneous immunity to C. albicans requires T helper-17 (Th17) cell differentiation that is thought to depend on recognition of filamentous C. albicans. Systemic immunity is considered T cell independent. Using a murine skin infection model, we compared T helper cell responses to yeast and filamentous C. albicans, We found that only yeast induced Th17 cell responses through a mechanism tha...

  2. Ultrastructural and biochemical studies of two dynamically expressed cell surface determinants on Candida albicans.

    OpenAIRE

    Brawner, D L; Cutler, J E

    1986-01-01

    Variability in the expression of two different cell surface carbohydrate determinants was examined with two agglutinating immunoglobulin M monoclonal antibodies (H9 and C6) and immunoelectron microscopy during growth of three strains of Candida albicans. A single strain of Candida parapsilosis did not express either antigen at any time during growth. Antigens were detected on the surface of C. albicans by agglutination tests with either H9 or C6 over a 48-h growth period. The difference in sp...

  3. Stage specific assessment of Candida albicans phagocytosis by macrophages identifies cell wall composition and morphogenesis as key determinants.

    Directory of Open Access Journals (Sweden)

    Leanne E Lewis

    Full Text Available Candida albicans is a major life-threatening human fungal pathogen. Host defence against systemic Candida infection relies mainly on phagocytosis of fungal cells by cells of the innate immune system. In this study, we have employed video microscopy, coupled with sophisticated image analysis tools, to assess the contribution of distinct C. albicans cell wall components and yeast-hypha morphogenesis to specific stages of phagocytosis by macrophages. We show that macrophage migration towards C. albicans was dependent on the glycosylation status of the fungal cell wall, but not cell viability or morphogenic switching from yeast to hyphal forms. This was not a consequence of differences in maximal macrophage track velocity, but stems from a greater percentage of macrophages pursuing glycosylation deficient C. albicans during the first hour of the phagocytosis assay. The rate of engulfment of C. albicans attached to the macrophage surface was significantly delayed for glycosylation and yeast-locked morphogenetic mutant strains, but enhanced for non-viable cells. Hyphal cells were engulfed at a slower rate than yeast cells, especially those with hyphae in excess of 20 µm, but there was no correlation between hyphal length and the rate of engulfment below this threshold. We show that spatial orientation of the hypha and whether hyphal C. albicans attached to the macrophage via the yeast or hyphal end were also important determinants of the rate of engulfment. Breaking down the overall phagocytic process into its individual components revealed novel insights into what determines the speed and effectiveness of C. albicans phagocytosis by macrophages.

  4. A rapid [3H]glucose incorporation assay for determination of lymphoid cell-mediated inhibition of Candida albicans growth

    International Nuclear Information System (INIS)

    [3H]glucose uptake by Candida albicans after interaction with lymphoid effector cells was used to provide a quick, accurate and objective assessment of the growth inhibitory potential of lymphoid cells on candida. After 18 h coincubation of effector cells with candida, [3H]glucose was added for 3 h and the amount of radiolabel incorporated into residual candida was measured. The results showed that [3H]glucose uptake was proportional to the number of candida organisms left in the microwell and is dose dependent on the effector/target (E/T) ratio. At an E/T ratio of 300/1, complete inhibition of candida was seen, with significant inhibition still present at 30/1. In addition, monocytes and polymorphonuclear cells were found to be the primary cells responsible for eliminating candida. (Auth.)

  5. Melanin Externalization in Candida albicans Depends on Cell Wall Chitin Structures▿

    OpenAIRE

    Walker, Claire A; Gómez, Beatriz L.; Mora-Montes, Héctor M.; Mackenzie, Kevin S; Munro, Carol A.; Brown, Alistair J. P.; Gow, Neil A. R.; Kibbler, Christopher C.; Odds, Frank C.

    2010-01-01

    The fungal pathogen Candida albicans produces dark-pigmented melanin after 3 to 4 days of incubation in medium containing l-3,4-dihydroxyphenylalanine (l-DOPA) as a substrate. Expression profiling of C. albicans revealed very few genes significantly up- or downregulated by growth in l-DOPA. We were unable to determine a possible role for melanin in the virulence of C. albicans. However, we showed that melanin was externalized from the fungal cells in the form of electron-dense melanosomes tha...

  6. Quantitative and qualitative analyses of the cell death process in Candida albicans treated by antifungal agents.

    Science.gov (United States)

    Kim, Kyung Sook; Kim, Young-Sun; Han, Ihn; Kim, Mi-Hyun; Jung, Min Hyung; Park, Hun-Kuk

    2011-01-01

    The death process of Candida albicans was investigated after treatment with the antifungal agents flucytosine and amphotericin B by assessing morphological and biophysical properties associated with cell death. C. albicans was treated varying time periods (from 6 to 48 hours) and examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). SEM and AFM images clearly showed changes in morphology and biophysical properties. After drug treatment, the membrane of C. albicans was perforated, deformed, and shrunken. Compared to the control, C. albicans treated with flucytosine was softer and initially showed a greater adhesive force. Conversely, C. albicans treated with amphotericin B was harder and had a lower adhesive force. In both cases, the surface roughness increased as the treatment time increased. The relationships between morphological changes and the drugs were observed by AFM clearly; the surface of C. albicans treated with flucytosine underwent membrane collapse, expansion of holes, and shrinkage, while the membranes of cells treated with amphotericin B peeled off. According to these observations, the death process of C. albicans was divided into 4 phases, CDP(0), CDP(1), CDP(2), and CDP(4), which were determined based on morphological changes. Our results could be employed to further investigate the antifungal activity of compounds derived from natural sources. PMID:22174777

  7. Innate immune cell response upon Candida albicans infection.

    Science.gov (United States)

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

    2016-07-01

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

  8. Blood group glycolipids as epithelial cell receptors for Candida albicans.

    OpenAIRE

    Cameron, B J; Douglas, L J

    1996-01-01

    The role of glycosphingolipids as possible epithelial cell receptors for Candida albicans was examined by investigating the binding of biotinylated yeasts to lipids extracted from human buccal epithelial cells and separated on thin-layer chromatograms. Binding was visualized by the addition of 125I-streptavidin followed by autoradiography. Five C. albicans strains thought from earlier work to have a requirement for fucose-containing receptors all bound to the same three components in the lipi...

  9. Improved assay for surface hydrophobic avidity of Candida albicans cells.

    OpenAIRE

    Hazen, K C; LeMelle, W G

    1990-01-01

    A simple method that distinguishes among hydrophobic avidity levels of highly hydrophobic isolates of the pathogenic fungus Candida albicans is described. This method involves mixing polystyrene microspheres at different concentrations with a constant concentration of yeast cells and plotting the data in accordance with the Langmuir isotherm equation. A 10-fold difference between the C. albicans isolates with the lowest and highest avidity (KH) values was found. This method may also demonstra...

  10. Induction of apoptosis in oral epithelial cells by Candida albicans.

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    Villar, C Cunha; Chukwuedum Aniemeke, J; Zhao, X-R; Huynh-Ba, G

    2012-12-01

    During infection, interactions between Candida albicans and oral epithelial cells result in oral epithelial cell death. This is clinically manifested by the development of oral mucosal ulcerations generally associated with discomfort. In vitro studies have shown that C. albicans induces early apoptotic alterations in oral epithelial cells; however, these studies have also shown that treatment of infected cells with caspase inhibitors does not prevent their death. The reasons for these contradictory results are unknown and it is still not clear if C. albicans stimulates oral epithelial signaling pathways that promote apoptotic cell death. Activation of specific death pathways in response to microbial organisms plays an essential role in modulating the pathogenesis of a variety of infectious diseases. The aim of this study was to (i) characterize C. albicans-induced apoptotic morphological alterations in oral epithelial cells, and (ii) investigate the activation of apoptotic signaling pathways and expression of apoptotic genes during infection. Candida albicans induced early apoptotic changes in over 50% of oral epithelial cells. However, only 15% of those showed mid-late apoptotic alterations. At the molecular level, C. albicans caused a loss of the mitochondrial transmembrane potential and translocation of mitochondrial cytochrome c. Caspase-3/9 activities increased only during the first hours of infection. Moreover, poly[ADP ribose] polymerase 1 was cleaved into apoptotic and necrotic-like fragments. Finally, five anti-apoptotic genes were significantly upregulated and two pro-apoptotic genes were downregulated during infection. Altogether, these findings indicate that epithelial apoptotic pathways are activated in response to C. albicans, but fail to progress and promote apoptotic cell death. PMID:23134609

  11. Cell Wall Polysaccharides of Candida albicans Induce Mast Cell Degranulation in the Gut

    OpenAIRE

    Sakurai, Atsuko; Yamaguchi, Natsu; Sonoyama, Kei

    2012-01-01

    We investigated Candida albicans-induced mast cell degranulation in vitro and in vivo. Cell wall fraction but not culture supernatant and cell membrane fraction prepared from hyphally grown C. albicans induced β-hexosaminidase release in RBL-2H3 cells. Cell wall mannan and soluble β-glucan fractions also induced β-hexosaminidase release. Histological examination of mouse forestomach showed that C. albicans gut colonization induces mast cell degranulation. However, intragastric administration ...

  12. Binding of Candida albicans yeast cells to mouse popliteal lymph node tissue is mediated by macrophages.

    OpenAIRE

    Han, Y.; Van Rooijen, N.; Cutler, J E

    1993-01-01

    We previously reported that Candida albicans yeast cells adhere to the macrophage-rich medullary and subcapsular sinus areas of mouse lymph node tissue. To determine whether the yeast cell-lymph node interaction is mediated by macrophages, the effect of specific elimination of macrophages on yeast cell binding was studied, and yeast cell adherence was correlated with the ingestion of India ink by lymph node cells. Macrophage elimination was done by use of liposome-containing dichloromethylene...

  13. Baicalein induces programmed cell death in Candida albicans.

    Science.gov (United States)

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

    2009-08-01

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

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

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    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

  15. Anti-Candida albicans activity of Pichia anomala as determined by a growth rate reduction assay.

    OpenAIRE

    Sawant, A D; Abdelal, A T; Ahearn, D G

    1988-01-01

    Killer toxin activity of Pichia anomala WC65 appeared fungicidal for P. bimundalis WC38 and fungistatic for Candida albicans RC1. Inhibitory activity against sensitive C. albicans showed a linear relationship between toxin concentrations and the inverse of the reduced growth rates. The plot of toxin concentrations against growth rates was hyperbolic, as is characteristic of saturation kinetics. Sensitivity of C. albicans to the toxin decreased with increased cell age. The measurement of growt...

  16. Variability in expression of cell surface antigens of Candida albicans during morphogenesis.

    OpenAIRE

    Brawner, D L; Cutler, J. E.

    1986-01-01

    The location and expression of two different cell surface antigens on germinating and nongerminating Candida albicans cells was examined by using transmission electron microscopy after labeling with monoclonal antibodies (H9 or C6) and immunocolloidal gold. Immunodeterminant expression of the two carbohydrate antigens was followed from early germination events through 20 h of development. The determinant detected by H9 antibody, which was initially lost from the mother cell surface and prefer...

  17. Effect of surface treatments of titanium on amphotericin B-treated Candida albicans persister cells

    OpenAIRE

    Tsang, CSP; Tang, DYK

    2010-01-01

    Although persister cells in Candida albicans biofilm may contribute to its increased resistance to antifungal drugs, little information is available on the formation of Candida persister cells on titanium surfaces. The effect of different surface treatments of Ti on persister cells was determined in the present study. Titanium discs were surface-treated by three different methods (Group A - polishing, Group B - sandblasting followed by acid-etching, and Group C - sandblasting alone). Persiste...

  18. Bax-induced cell death in Candida albicans.

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    De Smet, Kris; Eberhardt, Ines; Reekmans, Rieka; Contreras, Roland

    2004-12-01

    Bax is a pro-apoptotic member of the Bcl-2 family of proteins involved in the regulation of genetically programmed cell death in mammalian cells. It has been shown that heterologous expression of Bax in several yeast species, such as Saccharomyces cerevisiae, Schizosaccharomyces pombe and Pichia pastoris, also induces cell death. In this study we investigated the effects of Bax expression in the pathogenic yeast Candida albicans. Cell death inducing expression of Bax required a synthetic BAX gene that was codon-optimized for expression in Candida albicans. Expression of this BAX gene resulted in growth inhibition and cell death. By fusing Bax with the yeast enhanced green fluorescent protein of Aequoria victoria, the cell death-inducing effect of Bax was increased due to reduced proteolytic degradation of Bax. Using this fusion protein we showed that, upon expression in C. albicans, Bax co-localizes with the mitochondria. Furthermore, we showed for the first time that expression of Bax in yeast causes the mitochondria, which are normally distributed throughout the cell, to cluster in the perinuclear region. PMID:15565645

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

    International Nuclear Information System (INIS)

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

  20. 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. PMID:27088599

  1. Influence of Various Ultraviolet Light Intensities on Pathogenic Determinants of Candida albicans

    OpenAIRE

    Mohammad K. Abu Sini; Khaled H. Abu-Elteen; Ali Z. Elkarmi; Mawieh A. Hamad; Rula F. Khuzaie

    2007-01-01

    The effect of pretreatment of Candida albicans with different UV light (360 nm) intensities (4, 6 and 10 W m-2) at different time intervals (6, 12, 24 and 48 h) in an attempt to investigate its influence on proteinase and phospholipase activities in correlation with in vitro adherence to Buccal Epithelial Cells (BECs) and lethality to mice were studied. Irradiated C. albicans cells were found to be less virulent than non-irradiated. Exposure of C. albicans to various doses of radiation led to...

  2. Th17 cells confer long-term adaptive immunity to oral mucosal Candida albicans infections.

    Science.gov (United States)

    Hernández-Santos, N; Huppler, A R; Peterson, A C; Khader, S A; McKenna, K C; Gaffen, S L

    2013-09-01

    Oropharyngeal candidiasis (OPC) is an opportunistic infection caused by Candida albicans. Despite its prevalence, little is known about C. albicans-specific immunity in the oral mucosa. Vaccines against Candida generate both T helper type 1 (Th1) and Th17 responses, and considerable evidence implicates interleukin (IL)-17 in immunity to OPC. However, IL-17 is also produced by innate immune cells that are remarkably similar to Th17 cells, expressing the same markers and localizing to similar mucosal sites. To date, the relative contribution(s) of Th1, Th17, and innate IL-17-producing cells in OPC have not been clearly defined. Here, we sought to determine the nature and function of adaptive T-cell responses to OPC, using a new recall infection model. Mice subjected to infection and re-challenge with Candida mounted a robust and stable antigen-specific IL-17 response in CD4+ but not CD8+ T cells. There was little evidence for Th1 or Th1/Th17 responses. The Th17 response promoted accelerated fungal clearance, and Th17 cells could confer protection in Rag1-/- mice upon adoptive transfer. Surprisingly, CD4 deficiency did not cause OPC but was instead associated with compensatory IL-17 production by Tc17 and CD3+CD4-CD8- cells. Therefore, classic CD4+Th17 cells protect from OPC but can be compensated by other IL-17-producing cells in CD4-deficient hosts. PMID:23250275

  3. 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.

  4. Cigarette smoke-exposed Candida albicans increased chitin production and modulated human fibroblast cell responses.

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    Alanazi, Humidah; Semlali, Abdelhabib; Perraud, Laura; Chmielewski, Witold; Zakrzewski, Andrew; Rouabhia, Mahmoud

    2014-01-01

    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. PMID:25302312

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

    OpenAIRE

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

    1995-01-01

    Candida albicans ATCC 10261 and CA2 bound to cells of the oral bacteria Streptococcus gordonii, Streptococcus oralis, and Streptococcus sanguis when these bacteria were immobilized onto microtiter plate wells, but they did not bind to cells of Streptococcus mutans or Streptococcus salivarius. Cell wall polysaccharide was extracted with alkali from S. gordonii NCTC 7869, the streptococcal species to which C. albicans bound with highest affinity, and was effective in blocking the coaggregation ...

  6. Influence of growth conditions on cell surface hydrophobicity of Candida albicans and Candida glabrata.

    OpenAIRE

    Hazen, K C; Plotkin, B. J.; Klimas, D M

    1986-01-01

    The effect of cultural conditions on cell surface hydrophobicity of Candida albicans and Candida glabrata was tested. C. albicans cells grown at room temperature were more hydrophobic than cells grown at 37 degrees C. No consistent pattern was observed with C. glabrata. Relative hydrophobicity was found to vary with the growth phase and growth medium for both species. The implications for pathogenesis studies are discussed.

  7. Memory IL-22-producing CD4+ T cells specific for Candida albicans are present in humans.

    Science.gov (United States)

    Liu, Yun; Yang, Binyan; Zhou, Maohua; Li, Li; Zhou, Hui; Zhang, Jianping; Chen, Hui; Wu, Changyou

    2009-06-01

    Co-expression of IL-22 and IL-17 has been identified and demonstrated to be involved in the immunopathogenesis of some autoimmune diseases as well as the defense against pathogenic infections in animal studies. However, the properties of IL-22-producing cells in humans remain largely unclear. In the present study, we showed that IL-22 could be induced from human PBMC following various polyclonal stimulations. The majority of IL-22-producing cells in PBMC were CD4(+) T cells with a memory cell phenotype. In addition, we found that a subset of IL-22(+) T cells produced IL-22 alone, whereas other IL-22(+) T cells co-expressed cytokines typical of Th1, Th2 and Th17 cells. Importantly, stimulation of PBMC from healthy adults with heat-inactivated Candida albicans (C. albicans) yeast or hyphae resulted in IL-22 production by central and effector memory CD4(+) T cells. Moreover, CD4(+)CCR6(+) but not CD4(+)CCR6(-) T cells produced IL-22 when stimulated with either C. albicans or PMA and ionomycin. In addition, PBMC from the individuals infected with C. albicans produced a significantly higher amount of IL-22 compared with healthy controls following stimulation with C. albicans. These data demonstrate that IL-22-producing T cells in humans may play an important role in the defense against fungal infections such as C. albicans. PMID:19449309

  8. A transmission electron microscopy study of the diversity of Candida albicans cells induced by Euphorbia hirta L. leaf extract in vitro

    Institute of Scientific and Technical Information of China (English)

    Abu Arra Basma; Zakaria Zuraini; Sreenivasan Sasidharan

    2011-01-01

    Objective: To determine the major changes in the microstructure of Candida albicans (C. albicans) after treatment with Euphorbia hirta (E. hirta) L. leaf extract. Methods: Transmission electron microscopy was used to study the ultrastructural changes caused by E. hirta extract on C.albicans cells at various exposure time. Results: It was found that the main abnormalities were the alterations in morphology, lysis and complete collapse of the yeast cells after 36 h of exposure to the extract. Whereas the control cultures showed a typical morphology of Candida with a uniform central density, typically structured nucleus, and a cytoplasm with several elements of endomembrane system and enveloped by a regular, intact cell wall. Conclusions: The significant antifungal activity shown by this methanol extract of E. hirta L. suggests its potential against infections caused by C. albicans. The extract may be developed as an anticandidal agent.

  9. A transmission electron microscopy study of the diversity of Candida albicans cells induced by Euphorbia hirta L.leaf extract in vitro

    Institute of Scientific and Technical Information of China (English)

    Abu; Arra; Basma; Zakaria; Zuraini; Sreenivasan; Sasidharan

    2011-01-01

    Objective:To determine the major changes in the microstructure of Candida albicans(C. albicans) after treatment with Euphorbia hirta(E.hirta) L.leaf extract.Methods:Transmission electron microscopy was used to study the ultrastructural changes caused by E.hirta extract on C. albicans cells al various exposure time.Results:It was found that the main abnormalities were the alterations in morphology,lysis and complete collapse of the yeast cells after 36 h of exposure to the extract.Whereas the control cultures showed a typical morphology of Candida with a uniform central density,typically structured nucleus,and a cytoplasm with several elements of endomembrane system and enveloped by a regular,intact cell wall.Conclusions:The significant antifungal activity shown by this methanol extract of E.hirta L.suggests its potential against infections caused by C.albicans.The extract may be developed as an anticandidal agent.

  10. Th17 cells confer long term adaptive immunity to oral mucosal Candida albicans infections

    OpenAIRE

    Hernández-Santos, Nydiaris; Huppler, Anna R; Peterson, Alanna C.; Khader, Shabaana A.; McKenna, Kyle C.; Sarah L Gaffen

    2012-01-01

    Oropharyngeal candidiasis (OPC) is an opportunistic infection caused by Candida albicans. Despite its prevalence, little is known about C. albicans-specific immunity in the oral mucosa. Vaccines against Candida generate both Th1 and Th17 responses, and considerable evidence implicates IL-17 in immunity to OPC. However, IL-17 is also produced by innate immune cells that are remarkably similar to Th17 cells, expressing the same markers and localizing to similar mucosal sites. To date, the relat...

  11. Silver colloidal nanoparticles : antifungal effect against Candida albicans and Candida glabrata adhered cells and biofilms

    OpenAIRE

    Monteiro, D. R.; Gorup, L. F.; Silva, Sónia Carina; Negri, M.; E. R. Camargo; Oliveira, Rosário; Barbosa, D. B.; Henriques, Mariana

    2011-01-01

    The aim of this study was to evaluate the effect of silver nanoparticles (SN) against Candida albicans and Candida glabrata adhered cells and biofilms. SN (average diameter 5 nm) were synthesized by silver nitrate reduction with sodium citrate and stabilized with ammonia. Minimal inhibitory concentration (MIC) tests were performed for C. albicans (n = 2) and C. glabrata (n = 2) grown in suspension following the Clinical Laboratory Standards Institute microbroth dilution method. SN were applie...

  12. Killed Candida albicans Yeasts and Hyphae Inhibit Gamma Interferon Release by Murine Natural Killer Cells

    OpenAIRE

    Murciano, Celia; Villamón, Eva; O'Connor, José-Enrique; Gozalbo, Daniel; Gil, M. Luisa

    2006-01-01

    Killed yeasts and hyphae of Candida albicans inhibit gamma interferon secretion by highly purified murine NK cells in response to the Toll-like receptor ligands lipopolysaccharide and zymosan. This effect, which is also observed in the presence of NK-activating cytokines (interleukin-2 [IL-2], IL-12, and IL-15), may represent a novel mechanism of immune evasion that contributes to the virulence of C. albicans.

  13. Killed Candida albicans yeasts and hyphae inhibit gamma interferon release by murine natural killer cells.

    Science.gov (United States)

    Murciano, Celia; Villamón, Eva; O'Connor, José-Enrique; Gozalbo, Daniel; Gil, M Luisa

    2006-02-01

    Killed yeasts and hyphae of Candida albicans inhibit gamma interferon secretion by highly purified murine NK cells in response to the Toll-like receptor ligands lipopolysaccharide and zymosan. This effect, which is also observed in the presence of NK-activating cytokines (interleukin-2 [IL-2], IL-12, and IL-15), may represent a novel mechanism of immune evasion that contributes to the virulence of C. albicans. PMID:16428793

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

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

  16. Candida albicans stimulates IL-23 release by human dendritic cells and downstream IL-17 secretion by Vδ1 T cells.

    Science.gov (United States)

    Maher, Christina O; Dunne, Katie; Comerford, Ross; O'Dea, Siobhán; Loy, Aisling; Woo, James; Rogers, Thomas R; Mulcahy, Fiona; Dunne, Pádraic J; Doherty, Derek G

    2015-06-15

    γδ T cells expressing the Vδ1 TCR are expanded in patients with HIV infection. We show in this article that circulating Vδ1 T cell numbers are particularly high in patients with HIV and candidiasis, and that these cells expand and produce IL-17 in response to Candida albicans in vitro. Although C. albicans could directly stimulate IL-17 production by a subset of Vδ1 T cells, fungus-treated dendritic cells (DCs) were required to expand C. albicans-responsive Vδ1 T cells to generate sufficient numbers of cells to release IL-17 at levels detectable by ELISA. C. albicans induced the release of IL-1β, IL-6, and IL-23 by DCs, but addition of these cytokines or supernatants of C. albicans-treated DCs to Vδ1 T cells was not sufficient to induce proliferation. We found that direct contact with DCs was required for Vδ1 T cell proliferation, whereas IL-23R-blocking studies showed that IL-23 was required for optimal C. albicans-induced IL-17 production. Because IL-17 affords protection against both HIV and C. albicans, and because Vδ1 T cells are not depleted by HIV, these cells are likely to be an important source of IL-17 in HIV-infected patients with candidiasis, in whom CD4(+) Th17 responses are impaired. These data show that C. albicans stimulates proliferation and IL-17 production by Vδ1 T cells by a mechanism that involves IL-23 release by DCs. PMID:25964489

  17. Glycosylation of Candida albicans cell wall proteins is critical for induction of innate immune responses and apoptosis of epithelial cells.

    OpenAIRE

    Wagener, Jeanette; Weindl, Günther; de Groot, Piet W. J.; de Boer, Albert D.; Kaesler, Susanne; Thavaraj, Selvam; Bader, Oliver; Mailänder-Sanchez, Daniela; Borelli, Claudia; Weig, Michael; Biedermann, Tilo; Naglik, Julian R.; Korting, Hans Christian; Schaller, Martin

    2012-01-01

    C. albicans is one of the most common fungal pathogen of humans, causing local and superficial mucosal infections in immunocompromised individuals. Given that the key structure mediating host-C. albicans interactions is the fungal cell wall, we aimed to identify features of the cell wall inducing epithelial responses and be associated with fungal pathogenesis. We demonstrate here the importance of cell wall protein glycosylation in epithelial immune activation with a predominant role for the ...

  18. 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.

  19. Comparison of cell wall proteins in putative Candida albicans & Candida dubliniensis by using modified staining method & SDS-PAGE

    OpenAIRE

    Yazdanparast, Seyed Amir; Nezarati, Seyedeh Shahrzad Mahdavi; Heshmati, Fariba; Hamzehlou, Sepideh

    2012-01-01

    Background Candida species are among the most common causes of opportunistic fungal diseases. Among Candida species, Candida albicans is responsible for most infections. Having many strains, C. albicans is very polymorph. C. dubliniensis is very similar to albicans species both morphologically and physiologically. For an infection to occur, cell wall proteins play an important role as they enable yeast to adhere to host cells and begin pathogenesis. Therefore, we decided to extract these prot...

  20. 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 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. PMID:26847045

  1. 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.

  2. Adherence of Candida albicans to oral epithelial cells differentiated by Papanicolaou staining.

    OpenAIRE

    Williams, D. W.; Walker, R; Lewis, M.A.; Allison, R T; Potts, A J

    1999-01-01

    OBJECTIVE: To examine the relative adherence of Candida albicans to oral epithelial cells differentiated by Papanicolaou staining. METHODS: Oral epithelial cells were collected from 10 healthy adults (five male, five female) and counted. Equal volumes of oral epithelial cells and candida were mixed and incubated. The epithelial cells from this mix were collected by filtration through 10 microns polycarbonate membrane filters. Cells retained on the membrane filters were stained with crystal vi...

  3. Higher concentration of CO2 and 37℃ stabilize the less virulent opaque cell of Candida albicans

    Institute of Scientific and Technical Information of China (English)

    LIU Ze-hu; LI Min; LU Xue-lian; SHE Xiao-dong; HU Su-quan; CHEN Wei; LIU Wei-da

    2010-01-01

    Background Candida albicans (C. albicans) strains can spontaneously switch at a very low frequency from white to opaque phase. The ability to switch reversibly between white and opaque phenotype and contributes to the pathogenicity of C. albicans. White and opaque switching can be induced by various environmental signals. Previous study showed that opaque cells switch en masse to white when transferred in vitro to 37℃, the temperature of their animal host. The objective of the present study was to determine the effect of different concentration of carbon dioxide and temperature on white-opaque switching, and to determine the different anti-candida killing activity of white and opaque form by human monocyte-macrophage cell line THP-1.Methods White-opaque switching and opaque-white switching were assayed. Modified Lee's medium supplemented with phloxine B was used to detect white and opaque forms of C. albicans under 0.03% CO2 at 25℃, 0.03% CO2 at 37℃ and 5% CO2 at 37℃. Growth curve of C. albicans was monitored using OD value at 630 nm simultaneously. White and opaque forms of C. albicans and THP-1 cells were cocultured at ratio of 1:10. Colony serial dilutions were used to assay for intracellular candidacidal activity. MTT assay was used to measure the extracellular candidacidal activity.Results Phenotype switching was successfully induced in vitro in all three strains of C. albicans. When evaluating white to opaque switching, opaque colony proportion of all colonies was 0.572±0.087, 0.920±0.030 and 0.985±0.026 exposure of white cells to 0.03% CO2 at 25℃, 0.03% CO2 at 37℃ and 5% CO2 at 37℃. When evaluating opaque to white switching, opaque colony proportion of all colonies was 0.600±0.114, 0.983±0.003 and 0.998±0.003 exposure of white cells to 0.03% CO2 at 25℃, 0.03% CO2 at 37℃ and 5% CO2 at 37℃. No significant difference of white or opaque form growth rate was found among three conditions (P>0.05). THP-1 mediated

  4. Endothelial Cell Injury Caused by Candida albicans Is Dependent on Iron

    OpenAIRE

    Fratti, Rutilio A.; Belanger, Paul H.; Ghannoum, Mahmoud A.; Edwards, John E.; Filler, Scott G.

    1998-01-01

    Although it is known that Candida albicans causes endothelial cell injury, in vitro and in vivo, the mechanism by which this process occurs remains unknown. Iron is critical for the induction of injury in many types of host cells. Therefore, we investigated the role of iron in Candida-induced endothelial cell injury. We found that pretreatment of endothelial cells with the iron chelators phenanthroline and deferoxamine protected them from candidal injury, even though the organisms germinated ...

  5. Enhancement of Candida albicans killing activity of separated human epidermal cells by ultraviolet radiation

    International Nuclear Information System (INIS)

    Ultraviolet irradiation enhanced the Candida albicans killing activity of freshly separated human epidermal cells in vitro. The simulation was dose-dependent and was not due to soluble extracellular factors acting on non-irradiated epidermal cells. The enhancement of the killing activity remained unchanged when epidermal cells were depleted of Langerhans cells. Protein synthesis inhibitors and prostaglandin antagonists inhibited the ultraviolet-induced augmentation of killing activity. (author)

  6. Differential adherence of hydrophobic and hydrophilic Candida albicans yeast cells to mouse tissues.

    OpenAIRE

    Hazen, K C; Brawner, D L; Riesselman, M H; Jutila, M A; Cutler, J E

    1991-01-01

    Using an ex vivo binding assay, we previously demonstrated that yeast cells grown at 37 degrees C display binding specificity in mouse spleen, lymph node, and kidney tissues. In spleen and lymph node tissues, binding was predominantly in regions rich in macrophages. Here, we tested the possibility that hydrophobic and hydrophilic cells bind differentially to host tissues. Hydrophobic and hydrophilic yeast cells of four Candida albicans strains were incubated for 15 min at 4 degrees C with cry...

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

    Science.gov (United States)

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

    2015-04-01

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

  8. In vitro Effects of Lemongrass Extract on Candida albicans Biofilms, Human Cells Viability, and Denture Surface

    Science.gov (United States)

    Madeira, Petrus L. B.; Carvalho, Letícia T.; Paschoal, Marco A. B.; de Sousa, Eduardo M.; Moffa, Eduardo B.; da Silva, Marcos A. dos Santos; Tavarez, Rudys de Jesus Rodolfo; Gonçalves, Letícia M.

    2016-01-01

    The purpose of this study was to investigate whether immersion of a denture surface in lemongrass extract (LGE) has effects on C. albicans biofilms, human cell viability and denture surface. Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) were performed for LGE against C. albicans. For biofilm analysis, discs were fabricated using a denture acrylic resin with surface roughness standardization. C. albicans biofilms were developed on saliva-coated discs, and the effects of LGE at MIC, 5XMIC, and 10XMIC were investigated during biofilm formation and after biofilm maturation. Biofilms were investigated for cell counting, metabolic activity, and microscopic analysis. The cytotoxicity of different concentrations of LGE to peripheral blood mononuclear cells (PBMC) was analyzed using MTT. The effects of LGE on acrylic resin were verified by measuring changes in roughness, color and flexural strength after 28 days of immersion. Data were analyzed by ANOVA, followed by a Tukey test at a 5% significance level. The minimal concentration of LGE required to inhibit C. albicans growth was 0.625 mg/mL, while MFC was 2.5 mg/mL. The presence of LGE during biofilm development resulted in a reduction of cell counting (p 0.05). There were no verified differences in color perception, roughness, or flexural strength after immersion in LGE at MIC compared to the control (p > 0.05). It could be concluded that immersion of the denture surface in LGE was effective in reducing C. albicans biofilms with no deleterious effects on acrylic properties at MIC. MIC was also an effective and safe concentration for use. PMID:27446818

  9. Protection against murine disseminated candidiasis mediated by a Candida albicans-specific T-cell line.

    OpenAIRE

    Sieck, T G; Moors, M A; Buckley, H R; Blank, K J

    1993-01-01

    The role of T lymphocytes in disseminated candidiasis in a mouse model of irradiation-induced immunosuppression was investigated. A continuously cultured Candida albicans-specific T-cell line mediated protection of sublethally irradiated mice from disseminated candidiasis as measured by both the fungal load in the kidneys and mortality. These results are the first to demonstrate directly a role for antigen-specific T cells in the protective immune response against murine disseminated candidia...

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

    Science.gov (United States)

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

    2015-08-01

    Microbial interactions are necessarily associated with the development of polymicrobial oral biofilms. The objective of this study was to determine the coaggregation of eight strains of Candida albicans with Actinomyces naeslundii and Streptococcus mutans. In autoaggregation assays, C. albicans strains were grown in RPMI-1640 and artificial saliva medium (ASM) whereas bacteria were grown in heart infusion broth. C. albicans, A. naeslundii and S. mutans were suspended to give 10(6), 10(7) and 10(8) cells mL(-1) respectively, in coaggregation buffer followed by a 1 h incubation. The absorbance difference at 620 nm (ΔAbs) between 0 h and 1 h was recorded. To study coaggregation, the same protocol was used, except combinations of microorganisms were incubated together. The mean ΔAbs% of autoaggregation of the majority of RPMI-1640-grown C. albicans was higher than in ASM grown. Coaggregation of C. albicans with A. naeslundii and/or S. mutans was variable among C. albicans strains. Scanning electron microscopy images showed that A. naeslundii and S. mutans coaggregated with C. albicans in dual- and triculture. In conclusion, the coaggregation of C. albicans, A. naeslundii and S. mutans is C. albicans strain dependent. PMID:26054855

  11. Evaluation of the Role of Candida albicans Agglutinin-Like Sequence (Als) Proteins in Human Oral Epithelial Cell Interactions

    OpenAIRE

    Murciano, Celia; Moyes, David L.; Runglall, Manohursingh; Tobouti, Priscila; Islam, Ayesha; HOYER, LOIS L.; Naglik, Julian R.

    2012-01-01

    The fungus C. albicans uses adhesins to interact with human epithelial surfaces in the processes of colonization and pathogenesis. The C. albicans ALS (agglutinin-like sequence) gene family encodes eight large cell-surface glycoproteins (Als1-Als7 and Als9) that have adhesive function. This study utilized C. albicans Δals mutant strains to investigate the role of the Als family in oral epithelial cell adhesion and damage, cytokine induction and activation of a MAPK-based (MKP1/c-Fos) signalin...

  12. Mast cells phagocyte Candida albicans and produce nitric oxide by mechanisms involving TLR2 and Dectin-1.

    Science.gov (United States)

    Pinke, Karen Henriette; Lima, Heliton Gustavo de; Cunha, Fernando Queiroz; Lara, Vanessa Soares

    2016-02-01

    Candida albicans (C. albicans) is a fungus commonly found in the human mucosa, which may cause superficial and systemic infections, especially in immunosuppression. Until now, the main actors in the defense against this fungus are the epithelial cells, neutrophils, macrophages/monocytes and dendritic cells. However, mast cells are strategically located to play a first line of anti-Candida defense and it has appropriate mechanisms to do it. As with other cells, the recognition of C. albicans occurs meanly via TLR2 and Dectin-1. We assess the TLR2/Dectin-1 involvement in phagocytosis and production of nitric oxide (NO) and reactive oxygen species (ROS) by mast cells challenged with C. albicans. Bone marrow-derived mast cells (MC) from wild type (Wt) or knockout (TLR2-/-) mice C57BL/6 were subjected to in vitro Dectin-1 blockade. After challenged with FITC-labeled C. albicans or zymosan, phagocytosis was analyzed by microscopy. The intracellular production of NO and ROS was measured by DAF-FM diacetate and CellROX Deep/Red Reagent kits. The nitrite formation and hydrogen peroxide release were analyzed by Griess reaction and Amplex Red Hydrogen Peroxide/Peroxidase Assay Kit. Wt/MC phagocytose C. albicans with production of intracellular NO, but not ROS. Moreover, increased levels of nitrite were also observed. The absence and/or blockade of TLR2/Dectin-1 caused significant decreased in C. albicans phagocytosis and NO production. Our results showed that mast cells are able to phagocytose and produce NO against C. albicans via TLR2/Dectin-1. Therefore, mast cells could be important during the course of Candida infection and as a therapeutic target. PMID:26421959

  13. A subset of IL-17+ mesenchymal stem cells possesses anti-Candida albicans effect

    Institute of Scientific and Technical Information of China (English)

    Ruili Yang; Yi Liu; Peyman Kelk; Cunye Qu; Kentaro Akiyama; Chider Chen; Ikiru Atsuta

    2013-01-01

    Bone marrow mesenchymal stem cells (MSCs) comprise a heterogeneous population of postnatal progenitor cells with profound immunomodulatory properties,such as upregulation of Foxp3+ regulatory T cells (Tregs) and downregulation of Th17 cells.However,it is unknown whether different MSC subpopulations possess the same range of immunomodulatory function.Here,we show that a subset of single colony-derived MSCs producing IL-17 is different from bulk MSC population in that it cannot upregulate Tregs,downregulate Th17 cells,or ameliorate disease phenotypes in a colitis mouse model.Mechanistically,we reveal that IL-17,produced by these MSCs,activates the NFκB pathway to downregulate TGF-β production in MSCs,resulting in abolishment of MSC-based immunomodulation.Furthermore,we show that NFκB is able to directly bind to TGF-β promoter region to regulate TGF-β expression in MSCs.Moreover,these IL-17+ MSCs possess anti-Candida albicans growth effects in vitro and therapeutic effect in C.albicans-infected mice.In summary,this study shows that MSCs contain an IL-17+ subset capable of inhibiting C.albicans growth,but attenuating MSC-based immunosuppression via NFκB-mediated downregulation of TGF-β.

  14. Sequential Dysfunction and Progressive Depletion of Candida albicans-Specific CD4 T Cell Response in HIV-1 Infection

    Science.gov (United States)

    Liu, Fengliang; Fan, Xiuzhen; Auclair, Sarah; Ferguson, Monique; Sun, Jiaren; Soong, Lynn; Hou, Wei; Redfield, Robert R.; Birx, Deborah L.; Ratto-Kim, Silvia; Robb, Merlin L.; Kim, Jerome H.; Michael, Nelson L.; Hu, Haitao

    2016-01-01

    Loss of immune control over opportunistic infections can occur at different stages of HIV-1 (HIV) disease, among which mucosal candidiasis caused by the fungal pathogen Candida albicans (C. albicans) is one of the early and common manifestations in HIV-infected human subjects. The underlying immunological basis is not well defined. We have previously shown that compared to cytomegalovirus (CMV)-specific CD4 cells, C. albicans-specific CD4 T cells are highly permissive to HIV in vitro. Here, based on an antiretroviral treatment (ART) naïve HIV infection cohort (RV21), we investigated longitudinally the impact of HIV on C. albicans- and CMV-specific CD4 T-cell immunity in vivo. We found a sequential dysfunction and preferential depletion for C. albicans-specific CD4 T cell response during progressive HIV infection. Compared to Th1 (IFN-γ, MIP-1β) functional subsets, the Th17 functional subsets (IL-17, IL-22) of C. albicans-specific CD4 T cells were more permissive to HIV in vitro and impaired earlier in HIV-infected subjects. Infection history analysis showed that C. albicans-specific CD4 T cells were more susceptible to HIV in vivo, harboring modestly but significantly higher levels of HIV DNA, than CMV-specific CD4 T cells. Longitudinal analysis of HIV-infected individuals with ongoing CD4 depletion demonstrated that C. albicans-specific CD4 T-cell response was preferentially and progressively depleted. Taken together, these data suggest a potential mechanism for earlier loss of immune control over mucosal candidiasis in HIV-infected patients and provide new insights into pathogen-specific immune failure in AIDS pathogenesis. PMID:27280548

  15. Identification of two germ-tube-specific cell wall antigens of Candida albicans.

    OpenAIRE

    Ponton, J; J. M. Jones

    1986-01-01

    Outer cell wall layers of intact yeast- and mycelial-phase Candida albicans B311 were extracted with dithiothreitol. Antisera against mycelial-phase organisms were absorbed with yeast-phase organisms or yeast-phase extract and used to stain Western blots of sodium dodecyl sulfate-polyacrylamide gels loaded with yeast- and mycelial-phase extracts. Autoradiography of gels loaded with extracts from organisms surface labeled with 125I was used to detect surface antigens containing proteins. Antig...

  16. Relationship between germination of Candida albicans and increased adherence to human buccal epithelial cells.

    OpenAIRE

    Kimura, L H; Pearsall, N N

    1980-01-01

    A strong correlation was shown between germination and increased adherence of Candida albicans to human buccal epithelial cells, indicating that germination or other changes in the fungi accompanying germination were responsible for enhanced adherence. Partial inhibition of germination by cysteine resulted in a comparably lower adherence. Preferential adherence of germinated fungi occurred in competition assays with nongerminated and germinated fungi. The enhanced adherence to human mucosal c...

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

    Science.gov (United States)

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

    2015-11-01

    Members of the Candida genus, including C. albicans and C. tropicalis are opportunistic fungal pathogens that are increasingly associated with gastrointestinal infections and inflammatory bowel diseases. In healthy populations, however, C. albicans and C. tropicalis are considered benign members of the mycobiome, and are presumably kept in check by the mucosal immune system. In this study, we demonstrate in mice that C. albicans and C. tropicalis are sampled by Peyer's patch (PP) dendritic cells (DCs). Uptake into gut-associated lymphoid tissues occurred rapidly and was at least partly M cell-dependent. C. albicans and C. tropicalis preferentially localized in (and persisted within) a recently identified sub- population of Peyer's patch DCs distinguished by their expression of the C-type lectin receptor, Langerin. This study is the first to identify a subset of PP DCs capable of sampling Candida species. PMID:26386376

  18. Effects of Aspirin and Other Nonsteroidal Anti-Inflammatory Drugs on Biofilms and Planktonic Cells of Candida albicans

    OpenAIRE

    Alem, Mohammed A. S.; Douglas, L. Julia

    2004-01-01

    Prostaglandins are now known to be produced by Candida albicans and may play an important role in fungal colonization. Their synthesis in mammalian cells is decreased by inhibitors of the cyclooxygenase isoenzymes required for prostaglandin formation. In the present study, a catheter disk model system was used to investigate the effects of nonsteroidal anti-inflammatory drugs (all cyclooxygenase inhibitors) on biofilm formation by three strains of C. albicans. Seven of nine drugs tested at a ...

  19. An Interspecies Regulatory Network Inferred from Simultaneous RNA-seq of Candida albicans Invading Innate Immune Cells

    OpenAIRE

    LanayTierney; JörgLinde; SaschaBrunke; BernhardHube; UlrikeSchöck

    2012-01-01

    The ability to adapt to diverse micro-environmental challenges encountered within a host is of pivotal importance to the opportunistic fungal pathogen Candida 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. ...

  20. SLA2 mutations cause SWE1-mediated cell cycle phenotypes in Candida albicans and Saccharomyces cerevisiae

    OpenAIRE

    Gale, Cheryl A.; Leonard, Michelle D.; Finley, Kenneth R.; Christensen, Leah; McClellan, Mark; Abbey, Darren; Kurischko, Cornelia; Bensen, Eric; Tzafrir, Iris; Kauffman, Sarah; Becker, Jeff; Berman, Judith

    2009-01-01

    The early endocytic patch protein Sla2 is important for morphogenesis and growth rates in Saccharomyces cerevisiae and Candida albicans, but the mechanism that connects these processes is not clear. Here we report that growth defects in cells lacking CaSLA2 or ScSLA2 are associated with a cell cycle delay that is influenced by Swe1, a morphogenesis checkpoint kinase. To establish how Swe1 monitors Sla2 function, we compared actin organization and cell cycle dynamics in strains lacking other c...

  1. Oral mucosal cell response to Candida albicans in transgenic mice expressing HIV-1.

    Science.gov (United States)

    de Repentigny, Louis; Lewandowski, Daniel; Aumont, Francine; Hanna, Zaher; Jolicoeur, Paul

    2009-01-01

    Controlled studies on the immunopathogenesis of mucosal candidiasis in HIV infection have been hampered by the lack of a relevant animal model. We have previously reported that oral Candida infection in CD4C/HIV transgenic mice expressing gene products of HIV-1 in immune cells and developing an AIDS-like disease closely mimics oropharyngeal candidiasis in human HIV infection. The role of defective dendritic cells and CD4+ T cells in impaired induction of protective immunity and in the phenotype of chronic oral carriage of C. albicans can now be investigated under controlled conditions in these transgenic mice. PMID:19089395

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

    International Nuclear Information System (INIS)

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

  3. Cytotoxicity of antimicrobial photodynamic inactivation on epithelial cells when co-cultured with Candida albicans.

    Science.gov (United States)

    Pellissari, Claudia Viviane Guimarães; Pavarina, Ana Claudia; Bagnato, Vanderlei Salvador; Mima, Ewerton Garcia de Oliveira; Vergani, Carlos Eduardo; Jorge, Janaina Habib

    2016-05-11

    This study assessed the cytotoxicity of antimicrobial Photodynamic Inactivation (aPDI), mediated by curcumin, using human keratinocytes co-cultured with Candida albicans. Cells and microorganisms were grown separately for 24 hours and then kept in contact for an additional 24 hours. After this period, aPDI was applied. The conditions tested were: P+L+ (experimental group aPDI); P-L+ (light emitting diode [LED] group); P+L- (curcumin group); and P-L- (cells in co-culture without curcumin nor LED). In addition, keratinocytes and C. albicans were grown separately, were not placed in the co-culture and did not receive aPDI (control group). Cell proliferation was assessed using Alamar Blue, MTT, XTT and CFU tests. Qualitative and quantitative analyses were performed. Analysis of variance (ANOVA) was applied to the survival percentages of cells compared to the control group (considered as 100% viability), complemented by multiple comparisons using Tukey's test. A 5% significance level was adopted. The results of this study showed no interference in the metabolism of the cells in co-culture, since no differences were observed between the control group (cultured cells by themselves) and the P-L- group (co-culture cells without aPDI). The aPDI group reached the highest reduction (p = 0.009), which was equivalent to 1.7 log10 when compared to the control group. The P+L-, P-L+, P-L- and control groups were not statistically different (ρ > 0.05). aPDI inhibited the growth of keratinocytes and C. albicans in all tests, so the therapy was considered slightly (inhibition between 25 and 50% compared to the control group) to moderately (inhibition between 50 and 75% compared to the control group) cytotoxic. PMID:27110908

  4. Effects of 8-methoxypsoralen plus 365nm UVA light on Candida albicans cells

    International Nuclear Information System (INIS)

    Candida (C.) albicans cells were exposed to 8-Methoxypsoralen (8-MOP) concentrations of 1.0 μg/ml and 10.0 μg/ml medium and irradiated with 365 nm light. The amount of energy emitted was 4.8J/cm2. Two divergent types of cell damage occured concerning yeast cell cytoplasm and cell wall. Two hours after exposure cytoplasmic changes involving mitochondria, which showed irregularities in shape, blurred appearance or loss of mitochondrial cristae and outer membrane were seen. The number of vacuoles was increased. The cytoplasm showed large electron transparent areas, the cytoplasmic membrane disappeared in some areas completely. Nucleus and nuclear envelope usually remained intact in early stages. 24h after exposure conspicuous cell wall alterations were observed in addition to cytoplasmic changes. Newly produced cell wall material formed ball-like protrusions or was adherent sickle-shaped to the cell wall. The investigations strongly suggest that the results found after 8-MOP-UVA treatment of C. albicans cells can not be interpreted in the sense of a general cytotoxic effect. Apparently it takes the form of a combination of events involving regressive and progressive alterations. (orig.)

  5. [Determination of a Candida albicans antigen using an amperometric immunoenzyme sensor].

    Science.gov (United States)

    Kutyreva, M P; Mediantseva, E P; Khaldeeva, E V; Glushko, N I; Budnikov, G K

    1998-01-01

    Determination new variant enzyme immunoassay with amperometric enzyme immunosensor, including the immobilizing enzyme-choline esterase and antibodies against Candida albicans (CA) in biosensitivity part of sensor, for diagnose disease of CA. The method for determination of CA based on combination immunochemical reactions and voltammetric indication of analytical signal was developed. Amperometric enzyme immunosensor developed has been used as detector. Differences dilutions of antibody (Ab) against antigen (Ag) of CA immobilizing in common with choline esterase (CE). The method of immobilization developed allows to receive the sensor with including the immobilized CE and Ab in common. The method of determination of CA based on combination the reaction of forming immune complex tAb-AgI with enzyme immunosensor for its detection. The dynamic range of concentrations determined of Ag depends on degree of dilution of Ab used for manufactory biosensitivity part of sensor. The data indicate that the [Ab-Ag] immune complexes are stable. This is also confirmed by the values of [Ab-Ag] binding constants, obtained in Scatchard coordinates. This method of determination doesn't require special preparation of a sample. Selectivity, sensitivity, simplicity and quickness are characterize of this method which could be used for manufacturing test-sistem for determination CA in blood. PMID:9634720

  6. Candida albicans killing by RAW 264.7 mouse macrophage cells: effects of Candida genotype, infection ratios, and gamma interferon treatment.

    Science.gov (United States)

    Marcil, A; Harcus, D; Thomas, D Y; Whiteway, M

    2002-11-01

    Phagocytic cells such as neutrophils and macrophages are potential components of the immune defense that protects mammals against Candida albicans infection. We have tested the interaction between the mouse macrophage cell line RAW 264.7 and a variety of mutant strains of C. albicans. We used an end point dilution assay to monitor the killing of C. albicans at low multiplicities of infection (MOIs). Several mutants that show reduced virulence in mouse systemic-infection models show reduced colony formation in the presence of macrophage cells. To permit analysis of the macrophage-Candida interaction at higher MOIs, we introduced a luciferase reporter gene into wild-type and mutant Candida cells and used loss of the luminescence signal to quantify proliferation. This assay gave results similar to those for the end point dilution assay. Activation of the macrophages with mouse gamma interferon did not enhance anti-Candida activity. Continued coculture of the Candida and macrophage cells eventually led to death of the macrophages, but for the RAW 264.7 cell line this was not due to apoptotic pathways involving caspase-8 or -9 activation. In general Candida cells defective in the formation of hyphae were both less virulent in animal models and more sensitive to macrophage engulfment and growth inhibition. However the nonvirulent, hypha-defective cla4 mutant line was considerably more resistant to macrophage-mediated inhibition than the wild-type strain. Thus although mutants sensitive to engulfment are typically less virulent in systemic-infection models, sensitivity to phagocytic macrophage cells is not the unique determinant of C. albicans virulence. PMID:12379711

  7. Single-cell force spectroscopy of the medically important Staphylococcus epidermidis-Candida albicans interaction

    Science.gov (United States)

    Beaussart, Audrey; Herman, Philippe; El-Kirat-Chatel, Sofiane; Lipke, Peter N.; Kucharíková, Soňa; van Dijck, Patrick; Dufrêne, Yves F.

    2013-10-01

    Despite the clinical importance of bacterial-fungal interactions, their molecular details are poorly understood. A hallmark of such medically important interspecies associations is the interaction between the two nosocomial pathogens Staphylococcus aureus and Candida albicans, which can lead to mixed biofilm-associated infections with enhanced antibiotic resistance. Here, we use single-cell force spectroscopy (SCFS) to quantify the forces engaged in bacterial-fungal co-adhesion, focusing on the poorly investigated S. epidermidis-C. albicans interaction. Force curves recorded between single bacterial and fungal germ tubes showed large adhesion forces (~5 nN) with extended rupture lengths (up to 500 nm). By contrast, bacteria poorly adhered to yeast cells, emphasizing the important role of the yeast-to-hyphae transition in mediating adhesion to bacterial cells. Analysis of mutant strains altered in cell wall composition allowed us to distinguish the main fungal components involved in adhesion, i.e. Als proteins and O-mannosylations. We suggest that the measured co-adhesion forces are involved in the formation of mixed biofilms, thus possibly as well in promoting polymicrobial infections. In the future, we anticipate that this SCFS platform will be used in nanomedicine to decipher the molecular mechanisms of a wide variety of pathogen-pathogen interactions and may help in designing novel anti-adhesion agents.

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

    Science.gov (United States)

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

    2016-07-01

    We evaluated the inhibitory effects of the probiotic Lactobacillus species on different phases of Candida albicans biofilm development. Quantification of biofilm growth and ultrastructural analyses were performed on C. albicans biofilms treated with Lactobacillus rhamnosus, Lactobacillus casei, and Lactobacillus acidophilus planktonic cell suspensions as well as their supernatants. Planktonic lactobacilli induced a significant reduction (p probiotic strain and the biofilm phase. L. rhamnosus supernatants had no significant effect on the mature biofilm (p > 0.05), but significantly reduced the early stages of Candida biofilm formation (p probiotic Lactobacillus on C. albicans entailed both cell-cell interactions and secretion of exometabolites that may impact on pathogenic attributes associated with C. albicans colonization on host surfaces and yeast filamentation. This study clarifies, for the first time, the mechanics of how Lactobacillus species may antagonize C. albicans host colonization. Our data elucidate the inhibitory mechanisms that define the probiotic candicidal activity of lactobacilli, thus supporting their utility as an adjunctive therapeutic mode against mucosal candidal infections. PMID:27087525

  9. Adherence and Blocking of Candida Albicans to Cultured Vaginal Epithelial Cells: Treatments to Decrease Adherence

    Directory of Open Access Journals (Sweden)

    Bryan Larsen

    2006-06-01

    Full Text Available Background. Pathogenesis of mucosal microorganisms depends on adherence to the tissues they colonize and infect. For Candida albicans, cell surface hydrophobicity may play a significant role in tissue binding ability. Methods. A continuous cell line of vaginal epithelial cells (VEC was grown in keratinocyte serum-free medium (KSFM with supplements and harvested by trypsinization. VEC were combined with yeast cells to evaluate adherence and inhibition of adherence. In this experimental setup, yeast stained with fluorescein isothiocyanate were allowed to attach to VEC and the resulting fluorescent VEC were detected by flow cytometry. Results. VEC were cultured and examined daily after plating and showed morphology similar to basal epithelial cells. Culture media supplemented with estradiol showed increased VEC proliferation initially (first 24 h but cell morphology was not altered. Fluorescinated Candida cells bound effectively to the cultured VEC. Using fresh cells exposed to various preparations of K-Y, we showed that all formulations of the product reduced Candida binding to VEC by 25% to 50%. While VEC were generally harvested for use in experiments when they were near confluent growth, we allowed some cultures to grow beyond that point and discovered that cells allowed to become overgrown or stressed appeared to bind yeast cells more effectively. Conclusion. Flow cytometry is a useful method for evaluating binding of stained yeast cells to cultured VEC and has demonstrated that commercially available products have the ability to interfere with the process of yeast adherence to epithelial cells.

  10. Trifluoromethanesulfonic acid-based proteomic analysis of cell wall and secreted proteins of the ascomycetous fungi Neurospora crassa and Candida albicans

    OpenAIRE

    Maddi, Abhiram; Bowman, Shaun M.; Free, Stephen J.

    2009-01-01

    Cell wall proteins from purified Candida albicans and Neurospora crassa cell walls were released using trifluoromethanesulfonic acid (TFMS) which cleaves the cell wall glucan/chitin matrix and deglycosylates the proteins. The cell wall proteins were then characterized by SDS PAGE and identified by proteomic analysis. The analyses for C. albicans identified 15 cell wall proteins and 6 secreted proteins. For N. crassa, the analyses identified 26 cell wall proteins and 9 secreted proteins. Most ...

  11. Members of the Candida parapsilosis complex and Candida albicans are differentially recognized by human peripheral blood mononuclear cells

    Directory of Open Access Journals (Sweden)

    Eine eEstrada-Mata

    2016-01-01

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

  12. Evaluation of caries-associated virulence of biofilms from Candida albicans isolated from saliva of pediatric patients with sickle-cell anemia.

    Science.gov (United States)

    Brighenti, Fernanda Lourenção; Medeiros, Amanda Coelho; Matos, Bruno Mello; Ribeiro, Zulene Eveline Abreu; Koga-Ito, Cristiane Yumi

    2014-01-01

    A previous study demonstrated that the amount of Candida spp. in saliva is higher in children with sickle-cell disease. The results from a recent study demonstrate its participation in the etiology of dental caries. Objective This study assessed caries-associated virulence (production of acid, extracellular polysaccharides, proteins and metabolic activity) of biofilms from Candida albicans isolated from saliva of patients with sickle-cell anemia in comparison to isolates obtained from matched healthy children. Material and Methods The isolates were previously obtained from 25 children (4-6 years) and their matched controls (healthy children). One isolate of C. albicans per children was used, totaling 25 isolates per group. The C. albicans biofilms were grown for five days and analyzed regarding the production of lactic acid, extracellular polysaccharides, proteins and metabolic activity. The production of lactic acid was determined by the enzymatic method. The concentration of extracellular polysaccharides was determined by the phenol-sulphuric acid method, and the concentration of the protein was analyzed using the QuantiPro BCA kit. The XTT reduction was used to verify the metabolic activity. The data were analyzed with GraphPad Prism at 5%. Results The Mean±standard deviation for acid production, extracellular polysaccharides, proteins and metabolic activity of isolates from sickle-cell group was, respectively: 7.1±5.0 mmol/L; 15.6±2.5 μg glucose/mg biofilm; 7,503±3,097 μg/mL; A490 3.5±0.7. For isolates from control group the values obtained were: 3.5±3.3 mmol/L; 12.8±3.4 μg glucose/mg biofilm; 4,995±682 μg/mL; A490 3.4±0.5. The C. albicans isolates from patients with sickle-cell anemia produced a significantly greater quantity of acids (p=0.025), polysaccharides (p=0.025) and proteins (p=0.047) compared with the isolates from control group. However, there was no difference in metabolic activity (XTT) between groups (p=0.750). Conclusion The C

  13. Evaluation of caries-associated virulence of biofilms from Candida albicans isolated from saliva of pediatric patients with sickle-cell anemia

    Directory of Open Access Journals (Sweden)

    Fernanda Lourenção BRIGHENTI

    2014-12-01

    Full Text Available A previous study demonstrated that the amount of Candida spp. in saliva is higher in children with sickle-cell disease. The results from a recent study demonstrate its participation in the etiology of dental caries. Objective This study assessed caries-associated virulence (production of acid, extracellular polysaccharides, proteins and metabolic activity of biofilms from Candida albicans isolated from saliva of patients with sickle-cell anemia in comparison to isolates obtained from matched healthy children. Material and Methods The isolates were previously obtained from 25 children (4-6 years and their matched controls (healthy children. One isolate of C. albicans per children was used, totaling 25 isolates per group. The C. albicans biofilms were grown for five days and analyzed regarding the production of lactic acid, extracellular polysaccharides, proteins and metabolic activity. The production of lactic acid was determined by the enzymatic method. The concentration of extracellular polysaccharides was determined by the phenol-sulphuric acid method, and the concentration of the protein was analyzed using the QuantiPro BCA kit. The XTT reduction was used to verify the metabolic activity. The data were analyzed with GraphPad Prism at 5%. Results The Mean±standard deviation for acid production, extracellular polysaccharides, proteins and metabolic activity of isolates from sickle-cell group was, respectively: 7.1±5.0 mmol/L; 15.6±2.5 μg glucose/mg biofilm; 7,503±3,097 μg/mL; A490 3.5±0.7. For isolates from control group the values obtained were: 3.5±3.3 mmol/L; 12.8±3.4 μg glucose/mg biofilm; 4,995±682 μg/mL; A490 3.4±0.5. The C. albicans isolates from patients with sickle-cell anemia produced a significantly greater quantity of acids (p=0.025, polysaccharides (p=0.025 and proteins (p=0.047 compared with the isolates from control group. However, there was no difference in metabolic activity (XTT between groups (p=0.750. Conclusion

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Expression of surface hydrophobic proteins by Candida albicans in vivo.

    OpenAIRE

    Glee, P M; Sundstrom, P; Hazen, K C

    1995-01-01

    Candida albicans modulates cell surface hydrophobicity during growth and morphogenesis in vitro. To determine if surface hydrophobicity is expressed during pathogenesis, we generated a polyclonal antiserum against yeast hydrophobic proteins. The antiserum was then used for indirect immunofluorescence analysis of tissues from mice colonized and chronically infected with C. albicans. Results demonstrated that yeast hydrophobic proteins are exposed on fungal cells present in host tissues. The po...

  16. Deletion of a Yci1 Domain Protein of Candida albicans Allows Homothallic Mating in MTL Heterozygous Cells

    Science.gov (United States)

    Sun, Yuan; Gadoury, Christine; Hirakawa, Matthew P.; Bennett, Richard J.; Harcus, Doreen; Marcil, Anne

    2016-01-01

    ABSTRACT It has been proposed that the ancestral fungus was mating competent and homothallic. However, many mating-competent fungi were initially classified as asexual because their mating capacity was hidden behind layers of regulation. For efficient in vitro mating, the essentially obligate diploid ascomycete pathogen Candida albicans has to change its mating type locus from heterozygous MTLa/α to homozygous MTLa/a or MTLα/α and then undergo an environmentally controlled epigenetic switch to the mating-competent opaque form. These requirements greatly reduce the potential for C. albicans mating. Deletion of the Yci1 domain gene OFR1 bypasses the need for C. albicans cells to change the mating type locus from heterozygous to homozygous prior to switching to the opaque form and mating and allows homothallic mating of MTL heterozygous strains. This bypass is carbon source dependent and does not occur when cells are grown on glucose. Transcriptional profiling of ofr1 mutant cells shows that in addition to regulating cell type and mating circuitry, Ofr1 is needed for proper regulation of histone and chitin biosynthesis gene expression. It appears that OFR1 is a key regulator in C. albicans and functions in part to maintain the cryptic mating phenotype of the pathogen. PMID:27118591

  17. Candida albicans up-regulates the Fas-L expression in liver Natural Killer and Natural Killer T cells.

    Science.gov (United States)

    Renna, María Sol; Figueredo, Carlos Mauricio; Rodríguez-Galán, María Cecilia; Icely, Paula Alejandra; Cejas, Hugo; Cano, Roxana; Correa, Silvia Graciela; Sotomayor, Claudia Elena

    2015-11-01

    After Candida albicans arrival to the liver, the local production of proinflammatory cytokines and the expanded intrahepatic lymphocytes (IHL) can be either beneficial or detrimental to the host. Herein we explored the balance between protective inflammatory reaction and liver damage, focusing our study on the contribution of TNF-α and Fas-Fas-L pathways in the hepatocellular apoptosis associated to C. albicans infection. A robust tissue reaction and a progressive increase of IL-1β, IL-6 and TNF-α were observed in infected animals. Blocking the biological activity of TNF-α did not modify the number of apoptotic cells observed in C. albicans infected animals. Fas-L molecule was up regulated on purified hepatic mononuclear cells and its expression progressed with the infection. In the IHL compartment, the absolute number of Fas-L+ NK and NKT cells increased on days 1 and 3 of the infection. C. albicans was also able to up regulate Fas-L expression in normal liver NK and NKT cells after in vitro contact. The innate receptor TLR2 was involved in this phenomenon. In the interplay between host factors and evasion strategies exploited by pathogens, the mechanism supported here could represent an additional way that allows this fungus to circumvent protective immune responses in the liver. PMID:26101139

  18. Proanthocyanidins polymeric tannin from Stryphnodendron adstringens are active against Candida albicans biofilms

    OpenAIRE

    Luiz, Raul Leal Faria; Vila, Taissa Vieira Machado; de Mello, João Carlos Palazzo; Nakamura, Celso Vataru; Rozental, Sonia; Ishida, Kelly

    2015-01-01

    Background Biofilm formation is important in Candida albicans pathogenesis and constitutes a mechanism of antifungal resistance. Thus, we evaluated the effect of proanthocyanidins polymer-rich fractions from Stryphnodendron adstringens (fraction F2 and subfraction F2.4) against C. albicans biofilms. Methods Firstly, the antifungal activity of F2 and F2.4 against planktonic cells of Candida albicans (ATCC 10231) was determined using broth microdilution method. Anti-biofilm effect of F2 and F2....

  19. Candida albicans Hyphal Formation and Virulence Assessed Using a Caenorhabditis elegans Infection Model ▿

    OpenAIRE

    Pukkila-Worley, Read; Peleg, Anton Y.; Tampakakis, Emmanouil; Mylonakis, Eleftherios

    2009-01-01

    Candida albicans colonizes the human gastrointestinal tract and can cause life-threatening systemic infection in susceptible hosts. We study here C. albicans virulence determinants using the nematode Caenorhabditis elegans in a pathogenesis system that models candidiasis. The yeast form of C. albicans is ingested into the C. elegans digestive tract. In liquid media, the yeast cells then undergo morphological change to form hyphae, which results in aggressive tissue destruction and death of th...

  20. Sap6, a secreted aspartyl proteinase, participates in maintenance the cell surface integrity of Candida albicans

    OpenAIRE

    Buu, Leh-Miauh; Chen, Yee-Chun

    2013-01-01

    Background The polymorphic species Candida albicans is the major cause of candidiasis in humans. The secreted aspartyl proteinases (Saps) of C. albicans, encoded by a family of 10 SAP genes, have been investigated as the virulent factors during candidiasis. However, the biological functions of most Sap proteins are still uncertain. In this study, we applied co-culture system of C. albicans and THP-1 human monocytes to explore the pathogenic roles and biological functions of Sap proteinases. R...

  1. Determination of germ tube, phospholipase, and proteinase production by bloodstream isolates of Candida albicans

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    Antonella Souza Mattei

    2013-06-01

    Full Text Available Introduction Candida albicans is a commensal and opportunistic agent that causes infection in immunocompromised individuals. Several attributes contribute to the virulence and pathogenicity of this yeast, including the production of germ tubes (GTs and extracellular hydrolytic enzymes, particularly phospholipase and proteinase. This study aimed to investigate GT production and phospholipase and proteinase activities in bloodstream isolates of C. albicans. Methods One hundred fifty-three C. albicans isolates were obtained from blood samples and analyzed for GT, phospholipase, and proteinase production. The assays were performed in duplicate in egg yolk medium containing bovine serum albumin and human serum. Results Detectable amounts of proteinase were produced by 97% of the isolates, and 78% of the isolates produced phospholipase. GTs were produced by 95% of the isolates. A majority of the isolates exhibited low levels of phospholipase production and high levels of proteinase production. Conclusions Bloodstream isolates of C. albicans produce virulence factors such as GT and hydrolytic enzymes that enable them to cause infection under favorable conditions.

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

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    Girolamo Antonietta

    2011-05-01

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

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

    Science.gov (United States)

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

    2011-03-01

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

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

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    LanayTierney

    2012-03-01

    comprising 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.

  5. The Cell Wall Protein Ecm33 of Candida albicans is Involved in Chronological Life Span, Morphogenesis, Cell Wall Regeneration, Stress Tolerance, and Host–Cell Interaction

    Science.gov (United States)

    Gil-Bona, Ana; Reales-Calderon, Jose A.; Parra-Giraldo, Claudia M.; Martinez-Lopez, Raquel; Monteoliva, Lucia; Gil, Concha

    2016-01-01

    Ecm33 is a glycosylphosphatidylinositol-anchored protein in the human pathogen Candida albicans. This protein is known to be involved in fungal cell wall integrity (CWI) and is also critical for normal virulence in the mouse model of hematogenously disseminated candidiasis, but its function remains unknown. In this work, several phenotypic analyses of the C. albicans ecm33/ecm33 mutant (RML2U) were performed. We observed that RML2U displays the inability of protoplast to regenerate the cell wall, activation of the CWI pathway, hypersensitivity to temperature, osmotic and oxidative stresses and a shortened chronological lifespan. During the exponential and stationary culture phases, nuclear and actin staining revealed the possible arrest of the cell cycle in RML2U cells. Interestingly, a “veil growth,” never previously described in C. albicans, was serendipitously observed under static stationary cells. The cells that formed this structure were also observed in cornmeal liquid cultures. These cells are giant, round cells, without DNA, and contain large vacuoles, similar to autophagic cells observed in other fungi. Furthermore, RML2U was phagocytozed more than the wild-type strain by macrophages at earlier time points, but the damage caused to the mouse cells was less than with the wild-type strain. Additionally, the percentage of RML2U apoptotic cells after interaction with macrophages was fewer than in the wild-type strain. PMID:26870022

  6. Determination of antibody levels to Candida albicans in healthy and hospitalised adults using a radioimmunoassay

    International Nuclear Information System (INIS)

    A radioimmunoassay for antibody to Candida albicans is described. The test uses whole, killed of organisms as the antigen and radiolabelled sheep anti-human globulins to quantitate different classes of antibody to C. albicans. The assay has been compared with an Ouchterlony precipitin method and found to be simpler, more rapid, and more sensitive than the latter. Results obtained from two groups of symptomless adults indicated that the range of antibody level was wider for a hospitalised group than for a group of blood transfusion donors, particularly in respect of IgG and IgA antibody. The reason for the increase of antibody in hospital patients was not clear but may have been related to antibiotic therapy. The difficulties in interpretation of Candida serology have therefore been re-assessed in the light of more detailed knowledge of the range and type of antibody to be expected in normal individuals. (author)

  7. Trifluoromethanesulfonic acid-based proteomic analysis of cell wall and secreted proteins of the ascomycetous fungi Neurospora crassa and Candida albicans.

    Science.gov (United States)

    Maddi, Abhiram; Bowman, Shaun M; Free, Stephen J

    2009-10-01

    Cell wall proteins from purified Candida albicans and Neurospora crassa cell walls were released using trifluoromethanesulfonic acid (TFMS) which cleaves the cell wall glucan/chitin matrix and deglycosylates the proteins. The cell wall proteins were then characterized by SDS-PAGE and identified by proteomic analysis. The analyses for C. albicans identified 15 cell wall proteins and six secreted proteins. For N. crassa, the analyses identified 26 cell wall proteins and nine secreted proteins. Most of the C. albicans cell wall proteins are found in the cell walls of both yeast and hyphae cells, but some cell type-specific cell wall proteins were observed. The analyses showed that the pattern of cell wall proteins present in N. crassa vegetative hyphae and conidia (asexual spores) are quite different. Almost all of the cell wall proteins identified in N. crassa have close homologs in the sequenced fungal genomes, suggesting that these proteins have important conserved functions within the cell wall. PMID:19555771

  8. Herpes Simplex Virus (HSV) Modulation of Staphylococcus aureus and Candida albicans Initiation of HeLa 299 Cell-Associated Biofilm.

    Science.gov (United States)

    Plotkin, Balbina J; Sigar, Ira M; Tiwari, Vaibhav; Halkyard, Scott

    2016-05-01

    Although herpes simplex virus type-1 (HSV-1), and type-2 (HSV-2), Staphylococcus aureus and Candida albicans co-habit the oral and genital mucosa, their interaction is poorly understood. We determined the effect HSV has on bacterial and/or fungal adherence, the initial step in biofilm formation. HeLa229 cells were infected with HSV-1 (KOS) gL86 or HSV-2 (KOS) 333gJ (-) at a multiplicity of infection (MOI) of 50 and 10. S. aureus (ATCC 25923) and/or C. albicans (yeast forms or germ tube forms) were co-incubated for 30 min (37 °C; 5 % CO2; 5:1 organism: HeLa cell ratio; n = 16) with virus-infected HeLa cells or uninfected HeLa cell controls. Post-incubation, the monolayers were washed (3x; PBS), lysed (RIPA), and the lysate plated onto Fungisel and/or mannitol salts agar for standard colony count. The level of HeLa-associated S. aureus was significantly decreased (P albicans yeast forms and germ tube approximately two-fold, respectively. The effect of S. aureus on germ tube and yeast form adherence to HSV-1- and HSV-2-infected cells was specific for the Candida phenotype tested. Our study suggests that HSV, while antagonist towards S. aureus adherence enhances Candida adherence. Furthermore, the combination of the three pathogens results in S. aureus adherence that is either unaffected, or partially restored depending on both the herpes viral species and the fungal phenotype present. PMID:26758707

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

    Science.gov (United States)

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

    2015-01-01

    To better understand the molecular events underlying vulvovaginal candidiasis, we established an in vitro system. Immortalized vaginal epithelial cells were infected with live, yeast form C. albicans and C. albicans cultured in the same medium without vaginal epithelial cells were used as control. In both cases a yeast to hyphae transition was robustly induced. Whole transcriptome sequencing was used to identify specific gene expression changes in C. albicans. Numerous genes leading to a yeast to hyphae transition and hyphae specific genes were upregulated in the control hyphae and the hyphae in response to vaginal epithelial cells. Strikingly, the GlcNAc pathway was exclusively triggered by vaginal epithelial cells. Functional analysis in our in vitro system revealed that the GlcNAc biosynthesis is involved in the adherence to, and the ability to kill, vaginal epithelial cells in vitro, thus indicating the key role for this pathway in the virulence of C. albicans upon vulvovaginal candidiasis. PMID:26366412

  10. Imbalanced Macrophage and Dendritic Cell Activations in Response to Candida albicans in a Murine Model of Diabetes Mellitus.

    Science.gov (United States)

    Venturini, James; Fraga-Silva, Thais Fernanda Campos; Marchetti, Camila Martins; Mimura, Luiza Ayumi Nishiyama; Conti, Bruno José; Golim, Márjorie de Assis; Mendes, Rinaldo Poncio; de Arruda, Maria Sueli Parreira

    2016-07-01

    Bloodstream infections caused by Candida species are responsible for high morbidity and mortality, and diabetes mellitus (DM) is an important underlying disease in candidemia episodes. Although DM patients show an enhanced proinflammatory profile, they are highly susceptible to mycobacterial and mycotic infections. Attempting to understand this paradox, we investigated if imbalanced macrophage and dendritic cell (DC) activations could be associated to high incidence and/or severity of Candida albicans infection in the hypoinsulinemia-hyperglycemia (HH) milieu. HH alloxan-induced mice were infected with C. albicans and peritoneal aderent phagocytes were co-cultured with or without lipopolyssaccharide or heat-killed C. albicans, and the production of cytotoxic metabolites, cytokines, and chemokines was evaluated. We also evaluated the surface expression of MHC-II and CD86 in splenic DCs. Our findings showed that both uninfected and C. albicans-infected HH mice showed less production of CCL2 and reduced expression of CD86 by peritoneal phagocytes and splenic DCs, respectively. PMID:27105208

  11. Intestinal Cell Tight Junctions Limit Invasion of Candida albicans through Active Penetration and Endocytosis in the Early Stages of the Interaction of the Fungus with the Intestinal Barrier.

    Directory of Open Access Journals (Sweden)

    Marianne Goyer

    Full Text Available C. albicans is a commensal yeast of the mucous membranes in healthy humans that can also cause disseminated candidiasis, mainly originating from the digestive tract, in vulnerable patients. It is necessary to understand the cellular and molecular mechanisms of the interaction of C. albicans with enterocytes to better understand the basis of commensalism and pathogenicity of the yeast and to improve the management of disseminated candidiasis. In this study, we investigated the kinetics of tight junction (TJ formation in parallel with the invasion of C. albicans into the Caco-2 intestinal cell line. Using invasiveness assays on Caco-2 cells displaying pharmacologically altered TJ (i.e. differentiated epithelial cells treated with EGTA or patulin, we were able to demonstrate that TJ protect enterocytes against invasion of C. albicans. Moreover, treatment with a pharmacological inhibitor of endocytosis decreased invasion of the fungus into Caco-2 cells displaying altered TJ, suggesting that facilitating access of the yeast to the basolateral side of intestinal cells promotes endocytosis of C. albicans in its hyphal form. These data were supported by SEM observations of differentiated Caco-2 cells displaying altered TJ, which highlighted membrane protrusions engulfing C. albicans hyphae. We furthermore demonstrated that Als3, a hypha-specific C. albicans invasin, facilitates internalization of the fungus by active penetration and induced endocytosis by differentiated Caco-2 cells displaying altered TJ. However, our observations failed to demonstrate binding of Als3 to E-cadherin as the trigger mechanism of endocytosis of C. albicans into differentiated Caco-2 cells displaying altered TJ.

  12. Analysis of cell wall extracts of Candida albicans by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot techniques.

    OpenAIRE

    Ponton, J; J. M. Jones

    1986-01-01

    Cell walls of intact yeast- and mycelial-phase Candida albicans B311 were extracted with different compounds: dithiothreitol, dithiothreitol with protease, dithiothreitol with lyticase, and dithiothreitol with protease followed by beta-glucuronidase with chitinase. Extracts were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot techniques. Dithiothreitol extracts contained the most satisfactory array of components for study. Analysis of these extracts demo...

  13. Langerhans cells require MyD88-dependent signals for Candida albicans response but not for contact hypersensitivity or migration.

    Science.gov (United States)

    Haley, Krystal; Igyártó, Botond Z; Ortner, Daniela; Bobr, Aleh; Kashem, Sakeen; Schenten, Dominik; Kaplan, Daniel H

    2012-05-01

    Langerhans cells (LC) are a subset of skin-resident dendritic cells (DC) that reside in the epidermis as immature DC, where they acquire Ag. A key step in the life cycle of LC is their activation into mature DC in response to various stimuli, including epicutaneous sensitization with hapten and skin infection with Candida albicans. Mature LC migrate to the skin-draining LN, where they present Ag to CD4 T cells and modulate the adaptive immune response. LC migration is thought to require the direct action of IL-1β and IL-18 on LC. In addition, TLR ligands are present in C. albicans, and hapten sensitization produces endogenous TLR ligands. Both could contribute to LC activation. We generated Langerin-Cre MyD88(fl) mice in which LC are insensitive to IL-1 family members and most TLR ligands. LC migration in the steady state, after hapten sensitization and postinfection with C. albicans, was unaffected. Contact hypersensitivity in Langerin-Cre MyD88(fl) mice was similarly unaffected. Interestingly, in response to C. albicans infection, these mice displayed reduced proliferation of Ag-specific CD4 T cells and defective Th17 subset differentiation. Surface expression of costimulatory molecules was intact on LC, but expression of IL-1β, IL-6, and IL-23 was reduced. Thus, sensitivity to MyD88-dependent signals is not required for LC migration, but is required for the full activation and function of LC in the setting of fungal infection. PMID:22442445

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

  15. Live Candida albicans suppresses production of reactive oxygen species in phagocytes.

    Science.gov (United States)

    Wellington, Melanie; Dolan, Kristy; Krysan, Damian J

    2009-01-01

    Production of reactive oxygen species (ROS) is an important aspect of phagocyte-mediated host responses. Since phagocytes play a crucial role in the host response to Candida albicans, we examined the ability of Candida to modulate phagocyte ROS production. ROS production was measured in the murine macrophage cell line J774 and in primary phagocytes using luminol-enhanced chemiluminescence. J774 cells, murine polymorphonuclear leukocytes (PMN), human monocytes, and human PMN treated with live C. albicans produced significantly less ROS than phagocytes treated with heat-killed C. albicans. Live C. albicans also suppressed ROS production in murine bone marrow-derived macrophages from C57BL/6 mice, but not from BALB/c mice. Live C. albicans also suppressed ROS in response to external stimuli. C. albicans and Candida glabrata suppressed ROS production by phagocytes, whereas Saccharomyces cerevisiae stimulated ROS production. The cell wall is the initial point of contact between Candida and phagocytes, but isolated cell walls from both heat-killed and live C. albicans stimulated ROS production. Heat-killed C. albicans has increased surface exposure of 1,3-beta-glucan, a cell wall component that can stimulate phagocytes. To determine whether surface 1,3-beta-glucan exposure accounted for the difference in ROS production, live C. albicans cells were treated with a sublethal dose of caspofungin to increase surface 1,3-beta-glucan exposure. Caspofungin-treated C. albicans was fully able to suppress ROS production, indicating that suppression of ROS overrides stimulatory signals from 1,3-beta-glucan. These studies indicate that live C. albicans actively suppresses ROS production in phagocytes in vitro, which may represent an important immune evasion mechanism. PMID:18981256

  16. Apoptosis of Candida albicans during the Interaction with Murine Macrophages: Proteomics and Cell-Death Marker Monitoring.

    Science.gov (United States)

    Cabezón, Virginia; Vialás, Vital; Gil-Bona, Ana; Reales-Calderón, Jose A; Martínez-Gomariz, Montserrat; Gutiérrez-Blázquez, Dolores; Monteoliva, Lucía; Molero, Gloria; Ramsdale, Mark; Gil, Concha

    2016-05-01

    Macrophages may induce fungal apoptosis to fight against C. albicans, as previously hypothesized by our group. To confirm this hypothesis, we analyzed proteins from C. albicans cells after 3 h of interaction with macrophages using two quantitative proteomic approaches. A total of 51 and 97 proteins were identified as differentially expressed by DIGE and iTRAQ, respectively. The proteins identified and quantified were different, with only seven in common, but classified in the same functional categories. The analyses of their functions indicated that an increase in the metabolism of amino acids and purine nucleotides were taking place, while the glycolysis and translation levels dropped after 3 h of interaction. Also, the response to oxidative stress and protein translation were reduced. In addition, seven substrates of metacaspase (Mca1) were identified (Cdc48, Fba1, Gpm1, Pmm1, Rct1, Ssb1, and Tal1) as decreased in abundance, plus 12 proteins previously described as related to apoptosis. Besides, the monitoring of apoptotic markers along 24 h of interaction (caspase-like activity, TUNEL assay, and the measurement of ROS and cell examination by transmission electron microscopy) revealed that apoptotic processes took place for 30% of the fungal cells, thus supporting the proteomic results and the hypothesis of macrophages killing C. albicans by apoptosis. PMID:27048922

  17. Adherence of cell surface mutants of Candida albicans to buccal epithelial cells and analyses of the cell surface proteins of the mutants.

    OpenAIRE

    Fukayama, M; Calderone, R A

    1991-01-01

    Strains of Candida albicans, selected on the basis of their reduced agglutination with a polyclonal anti-Candida antiserum, were tested for their adherence to human buccal epithelial cells (BEC). Of four strains, one (A9V2) had reduced binding to BEC in vitro. Adherence of wild type (wt) yeast cells (A9), as measured by the percentage of BEC with adhering Candida cells, was 73.4% +/- 3.8% compared with 49.3% +/- 3.1% for A9V2 (P less than 0.01). From yeast cells of A9 and A9V2, whole-cell ext...

  18. The Rbf1, Hfl1 and Dbp4 of Candida albicans regulate common as well as transcription factor-specific mitochondrial and other cell activities

    OpenAIRE

    Khamooshi, Kasra; Sikorski, Patricia; Sun, Nuo; Calderone, Richard; Li, Dongmei

    2014-01-01

    Background Our interest in Candida albicans mitochondria began with the identification of GOA1. We demonstrated its role in cell energy production, cross-talk among mitochondria and peroxisomes, non-glucose energy metabolism, maintenance of stationary phase growth, and prevention of premature apoptosis. Its absence results in avirulence. However, what regulated transcription of GOA1 was unknown. Results To identify transcriptional regulators (TRs) of GOA1, we screened a C. albicans TF knockou...

  19. Analysis of the response of Candida albicans cells to Silver(I).

    Science.gov (United States)

    Rowan, Raymond; McCann, Malachy; Kavanagh, Kevin

    2010-05-01

    The response of the pathogenic yeast Candida albicans to the silver(I) perchlorate salt (AgClO(4)) was assessed. By employing an anti-phospho-p38 MAPK antibody, dual phosphorylation of a high osmolarity protein (Hog1p) in C. albicans in the presence of AgClO(4) was demonstrated. Phosphorylation of C. albicans Hog1p in response to hydrogen peroxide or AgClO(4) resulted in the translocation of this mitogen-activated protein (MAP) kinase to the nucleus. Nuclear translocation of C. albicans activating protein-1 (Cap1p) was demonstrated by Western blot analysis and detected using polyclonal anti-Cap1p antibody. Upon AgClO(4)-induced translocation of Cap1p there was a concomitant activation of genes coding for glutathione reductase-1 and Mn-superoxide dismutase but no increase in the expression of flavin oxidoreductase or mitochondrial processing protease was recorded. In addition, exposure to AgClO(4) increased the activity of superoxide dismutase, glutathione reductase and catalase. The activation of C. albicans oxidative stress response genes and enzymes following exposure to AgClO(4) is evidence of the generation of oxidative stress within this medically important yeast. PMID:20370363

  20. Krüppel-like Factor 4 modulates interleukin-6 release in human dendritic cells after in vitro stimulation with Aspergillus fumigatus and Candida albicans.

    Science.gov (United States)

    Czakai, Kristin; Leonhardt, Ines; Dix, Andreas; Bonin, Michael; Linde, Joerg; Einsele, Hermann; Kurzai, Oliver; Loeffler, Jürgen

    2016-01-01

    Invasive fungal infections are associated with high mortality rates and are mostly caused by the opportunistic fungi Aspergillus fumigatus and Candida albicans. Immune responses against these fungi are still not fully understood. Dendritic cells (DCs) are crucial players in initiating innate and adaptive immune responses against fungal infections. The immunomodulatory effects of fungi were compared to the bacterial stimulus LPS to determine key players in the immune response to fungal infections. A genome wide study of the gene regulation of human monocyte-derived dendritic cells (DCs) confronted with A. fumigatus, C. albicans or LPS was performed and Krüppel-like factor 4 (KLF4) was identified as the only transcription factor that was down-regulated in DCs by both fungi but induced by stimulation with LPS. Downstream analysis demonstrated the influence of KLF4 on the interleukine-6 expression in human DCs. Furthermore, KLF4 regulation was shown to be dependent on pattern recognition receptor ligation. Therefore KLF4 was identified as a controlling element in the IL-6 immune response with a unique expression pattern comparing fungal and LPS stimulation. PMID:27346433

  1. Tetracycline Effects on Candida Albicans Virulence Factors

    OpenAIRE

    Logan McCool; Hanh Mai; Michael Essmann; Bryan Larsen

    2008-01-01

    Object. To determine if tetracycline, previously reported to increase the probability of developing symptomatic vaginal yeast infections, has a direct effect on Candida albicans growth or induction of virulent phenotypes. Method. In vitro, clinical isolates of yeast were cultivated with sublethal concentrations of tetracycline and yeast cell counts, hyphal formation, drug efflux pump activity, biofilm production, and hemolysin production were determined by previously reported methods. Resul...

  2. Oropharyngeal Candidiasis in HIV Infection: Analysis of Impaired Mucosal Immune Response to Candida albicans in Mice Expressing the HIV-1 Transgene

    OpenAIRE

    Louis de Repentigny; Mathieu Goupil; Paul Jolicoeur

    2015-01-01

    IL-17-producing Th17 cells are of critical importance in host defense against oropharyngeal candidiasis (OPC). Speculation about defective Th17 responses to oral C. albicans infection in the context of HIV infection prompted an investigation of innate and adaptive immune responses to Candida albicans in transgenic mice expressing the genome of HIV-1 in immune cells and displaying an AIDS-like disease. Defective IL-17 and IL-22-dependent mucosal responses to C. albicans were found to determin...

  3. EFFECTS OF SYSTEMIC FLUCONAZOLE THERAPY ON IN VITRO ADHESION OF CANDIDA ALBICANS TO BUCCAL EPITHELIAL CELLS AND CHANGES OF THE CELL SURFACE PROTEINS OF THE EPITHELIAL CELLS

    Institute of Scientific and Technical Information of China (English)

    吴绍熙; 郭宁如; 侯幼红

    1996-01-01

    This paper presented the effects of systemic fluconazole therapy via intravenous (IV) and oral (PO) administrations on the adhesion of Candida albicans (C. albicans) to the huccal epithelial ceils (BEC) from five treated patients with three candidosis, one mucornlycosis and one sporotrichosis and at the same time,an analysis of the cell surface proteins involving candidal adherent receptor in the BEC of the patients in the course of 7 days were exposed to 3H-leucine radiolabaled C. atbicans for in vitro eandidal adherent assay,and the BEC from first intake day and the last intake day of the patients were extracted by dithiothreitol(DTT)-iodoacetamide treatment for SDS-PAGE. These results indicate that the systemic iluconazole therapy resuks in the inhibitory effect of candldal adhesion to BEC of treated patients to prevent them from oral candidosis for a prolonged time, which is based on the absent surface protein (35KDa) of the BEC.

  4. 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.

  5. Candida albicans infection leads to barrier breakdown and a MAPK/NF-κB mediated stress response in the intestinal epithelial cell line C2BBe1.

    Science.gov (United States)

    Böhringer, Michael; Pohlers, Susann; Schulze, Sylvie; Albrecht-Eckardt, Daniela; Piegsa, Judith; Weber, Michael; Martin, Ronny; Hünniger, Kerstin; Linde, Jörg; Guthke, Reinhard; Kurzai, Oliver

    2016-07-01

    Intestinal epithelial cells (IEC) form a tight barrier to the gut lumen. Paracellular permeability of the intestinal barrier is regulated by tight junction proteins and can be modulated by microorganisms and other stimuli. The polymorphic fungus Candida albicans, a frequent commensal of the human mucosa, has the capacity of traversing this barrier and establishing systemic disease within the host. Infection of polarized C2BBe1 IEC with wild-type C. albicans led to a transient increase of transepithelial electric resistance (TEER) before subsequent barrier disruption, accompanied by a strong decline of junctional protein levels and substantial, but considerably delayed cytotoxicity. Time-resolved microarray-based transcriptome analysis of C. albicans challenged IEC revealed a prominent role of NF-κB and MAPK signalling pathways in the response to infection. Hence, we inferred a gene regulatory network based on differentially expressed NF-κB and MAPK pathway components and their predicted transcriptional targets. The network model predicted activation of GDF15 by NF-κB was experimentally validated. Furthermore, inhibition of NF-κB activation in C. albicans infected C2BBe1 cells led to enhanced cytotoxicity in the epithelial cells. Taken together our study identifies NF-κB activation as an important protective signalling pathway in the response of epithelial cells to C. albicans. PMID:26752615

  6. Characterizing the role of cell-wall β-1,3-exoglucanase Xog1p in Candida albicans adhesion by the human antimicrobial peptide LL-37.

    Directory of Open Access Journals (Sweden)

    Pei-Wen Tsai

    Full Text Available Candida albicans is the major fungal pathogen of humans. Its adhesion to host-cell surfaces is the first critical step during mucosal infection. Antimicrobial peptides play important roles in the first line of mucosal immunity against C. albicans infection. LL-37 is the only member of the human cathelicidin antimicrobial peptide family and is commonly expressed in various tissues, including epithelium. We previously showed that LL-37 significantly reduced C. albicans adhesion to plastic, oral epidermoid OECM-1 cells, and urinary bladders of female BALB/c mice. The inhibitory effect of LL-37 on cell adhesion occurred via the binding of LL-37 to cell-wall carbohydrates. Here we showed that formation of LL-37-cell-wall protein complexes potentially inhibits C. albicans adhesion to polystyrene. Using phage display and ELISA, we identified 10 peptide sequences that could bind LL-37. A BLAST search revealed that four sequences in the major C. albicans cell-wall β-1,3-exoglucanase, Xog1p, were highly similar to the consensus sequence derived from the 10 biopanned peptides. One Xog1p-derived peptide, Xog1p(90-115, and recombinant Xog1p associated with LL-37, thereby reversing the inhibitory effect of LL-37 on C. albicans adhesion. LL-37 reduced Xog1p activity and thus interrupted cell-wall remodeling. Moreover, deletion of XOG1 or another β-1,3-exoglucanase-encoding gene EXG2 showed that only when XOG1 was deleted did cellular exoglucanase activity, cell adhesion and LL-37 binding decrease. Antibodies against Xog1p also decreased cell adhesion. These data reveal that Xog1p, originally identified from LL-37 binding, has a role in C. albicans adhesion to polystyrene and, by inference, attach to host cells via direct or indirect manners. Compounds that target Xog1p might find use as drugs that prevent C. albicans infection. Additionally, LL-37 could potentially be used to screen for other cell-wall components involved in fungal cell adhesion.

  7. Pathway analysis of Candida albicans survival and virulence determinants in a murine infection model.

    Science.gov (United States)

    Becker, Jeffrey M; Kauffman, Sarah J; Hauser, Melinda; Huang, Liyin; Lin, Molly; Sillaots, Susan; Jiang, Bo; Xu, Deming; Roemer, Terry

    2010-12-21

    One potentially rich source of possible targets for antifungal therapy are those Candida albicans genes deemed essential for growth under the standard culture (i.e., in vitro) conditions; however, these genes are largely unexplored as drug targets because essential genes are not experimentally amenable to conventional gene deletion and virulence studies. Using tetracycline-regulatable promoter-based conditional mutants, we investigated a murine model of candidiasis in which repressing essential genes in the host was achieved. By adding doxycycline to the drinking water starting 3 days prior to (dox - 3D) or 2 days post (dox + 2D) infection, the phenotypic consequences of temporal gene inactivation were assessed by monitoring animal survival and fungal burden in prophylaxis and acute infection settings. Of 177 selected conditional shut-off strains tested, the virulence of 102 was blocked under both repressing conditions, suggesting that the corresponding genes are essential for growth and survival in a murine host across early and established infection periods. Among these genes were those previously identified as antifungal drug targets (i.e., FKS1, ERG1, and ERG11), verifying that this methodology can be used to validate potential new targets. We also identify genes either conditionally essential or dispensable for in vitro growth but required for survival and virulence, including those in late stage ergosterol synthesis, or early steps in fatty acid or riboflavin biosynthesis. This study evaluates the role of essential genes with respect to pathogen virulence in a large-scale, systems biology context, and provides a general method for gene target validation and for uncovering unexpected antimicrobial targets. PMID:21135205

  8. Candida albicans Targets a Lipid Raft/Dectin-1 Platform to Enter Human Monocytes and Induce Antigen Specific T Cell Responses.

    Directory of Open Access Journals (Sweden)

    Valeria de Turris

    Full Text Available Several pathogens have been described to enter host cells via cholesterol-enriched membrane lipid raft microdomains. We found that disruption of lipid rafts by the cholesterol-extracting agent methyl-β-cyclodextrin or by the cholesterol-binding antifungal drug Amphotericin B strongly impairs the uptake of the fungal pathogen Candida albicans by human monocytes, suggesting a role of raft microdomains in the phagocytosis of the fungus. Time lapse confocal imaging indicated that Dectin-1, the C-type lectin receptor that recognizes Candida albicans cell wall-associated β-glucan, is recruited to lipid rafts upon Candida albicans uptake by monocytes, supporting the notion that lipid rafts act as an entry platform. Interestingly disruption of lipid raft integrity and interference with fungus uptake do not alter cytokine production by monocytes in response to Candida albicans but drastically dampen fungus specific T cell response. In conclusion, these data suggest that monocyte lipid rafts play a crucial role in the innate and adaptive immune responses to Candida albicans in humans and highlight a new and unexpected immunomodulatory function of the antifungal drug Amphotericin B.

  9. Candida albicans and Streptococcus salivarius modulate IL-6, IL-8, and TNF-alpha expression and secretion by engineered human oral mucosa cells.

    Science.gov (United States)

    Mostefaoui, Yakout; Bart, Christian; Frenette, Michel; Rouabhia, Mahmoud

    2004-11-01

    We investigated the involvement of oral epithelial cells via two cytokines (IL-6 and TNF-alpha) and one chemokine (IL-8) in local defences against live yeast (Candida albicans) and bacteria (Streptococcus salivarius) using an engineered human oral mucosa model. We report that the yeast changed from the blastospore to the hyphal form and induced significant tissue disorganization at later contact periods (24 and 48 h) compared to the bacteria. However, this effect did not reduce the viability or total number of epithelial cells. Gene activation analyses revealed that IL-6, IL-8 and TNF-alpha mRNA levels rose in tissues in contact with live C. albicans or S. salivarius. Gene activation was followed by an upregulation of protein secretion. IL-6 levels were higher after contact with C. albicans than with S. salivarius. IL-8 levels after contact with S. salivarius were higher than with C. albicans. Our study suggests that S. salivarius is more efficient at inducing proinflammatory mediator release than C. albicans. These results provide additional evidence for the contribution of oral epithelial cells to the inflammatory response against fungi and bacteria. PMID:15469436

  10. Mannoprotein Adhesin of Candida albicans Germ Tubes

    OpenAIRE

    VARDAR-ÜNLÜ, Gülhan

    1998-01-01

    The production and detection of a mannoprotein adhesin (MPA) of the hyphal-form cells of C. albicans on plastic petri dishes was investigated. Using Concanavalin A-coated latex microspheres, the MPA was detected on the plastic surface on which C. albicans produced germ tubes. The adhesin was extracted using dithiothreitol and iodoacetamide. It did not inhibit the adhesion of the yeast-form C. albicans to buccal epithelial cells (BEC). This suggested that the MPA of the hyphal-form ...

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

    Science.gov (United States)

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

    2015-10-01

    Candida albicans is an opportunistic fungal pathogen found as part of the normal oral flora. It can be coisolated with Fusobacterium nucleatum, an opportunistic bacterial pathogen, from oral disease sites, such as those involved in refractory periodontitis and pulp necrosis. The physical coadherence between these 2 clinically important microbes has been well documented and suggested to play a role in facilitating their oral colonization and colocalization and contributing to polymicrobial pathogenesis. Previous studies indicated that the physical interaction between C. albicans and F. nucleatum was mediated by the carbohydrate components on the surface of C. albicans and the protein components on the Fusobaterium cell surface. However, the identities of the components involved still remain elusive. This study was aimed at identifying the genetic determinants involved in coaggregation between the 2 species. By screening a C. albicans SN152 mutant library and a panel of F. nucleatum 23726 outer membrane protein mutants, we identified FLO9, which encodes a putative adhesin-like cell wall mannoprotein of C. albicans and radD, an arginine-inhibitable adhesin-encoding gene in F. nucleatum that is involved in interspecies coadherence. Consistent with these findings, we demonstrated that the strong coaggregation between wild-type F. nucleatum 23726 and C. albicans SN152 in an in vitro assay could be greatly inhibited by arginine and mannose. Our study also suggested a complex multifaceted mechanism underlying physical interaction between C. albicans and F. nucleatum and for the first time revealed the identity of major genetic components involved in mediating the coaggregation. These observations provide useful knowledge for developing new targeted treatments for disrupting interactions between these 2 clinically relevant pathogens. PMID:26152186

  12. Resistance of Candida albicans biofilms to antifungal agents in vitro.

    OpenAIRE

    Hawser, S. P.; Douglas, L J

    1995-01-01

    Biofilms formed by Candida albicans on small discs of catheter material were resistant to the action of five clinically important antifungal agents as determined by [3H]leucine incorporation and tetrazolium reduction assays. Fluconazole showed the greatest activity, and amphotericin B showed the least activity against biofilm cells. These findings were confirmed by scanning electron microscopy of the biofilms.

  13. Hairpin dsRNA does not trigger RNA interference in Candida albicans cells

    OpenAIRE

    Staab, Janet F.; White, Theodore C.; Marr, Kieren A.

    2010-01-01

    RNA interference/silencing mechanisms triggered by double-stranded RNA (dsRNA) have been described in many eukaryotes, including fungi. These mechanisms have in common small RNA molecules (siRNAs or microRNAs) originating from dsRNAs that, together with the effector protein Argonaute, mediate silencing. The genome of the fungal pathogen Candida albicans harbours a well-conserved Argonaute and a non-canonical Dicer, essential members of silencing pathways. Prototypical siRNAs are detected as m...

  14. Cell surface changes in the Candida albicans mitochondrial mutant goa1Δ are associated with reduced recognition by innate immune cells

    OpenAIRE

    She, Xiaodong; Zhang, Lulu; Chen, Hui; Calderone, Richard; Li, Dongmei

    2013-01-01

    We have previously characterized several fungal-specific proteins from the human pathogen Candida albicans that either encode subunits of mitochondria Complex I (CI) of the electron transport chain (ETC) or regulate CI activity (Goa1p). Herein, the role of energy production and cell wall gene expression is investigated in the mitochondria mutant goa1Δ. We show that down regulation of cell wall-encoding genes in the goa1Δ results in sensitivity to cell wall inhibitors such as congo red and cal...

  15. Membrane damage as first and DNA as the secondary target for anti-candidal activity of antimicrobial peptide P7 derived from cell-penetrating peptide ppTG20 against Candida albicans.

    Science.gov (United States)

    Li, Lirong; Song, Fengxia; Sun, Jin; Tian, Xu; Xia, Shufang; Le, Guowei

    2016-06-01

    P7, a peptide analogue derived from cell-penetrating peptide ppTG20, possesses antibacterial and antitumor activities without significant hemolytic activity. In this study, we investigated the antifungal effect of P7 and its anti-Candida acting mode in Candida albicans. P7 displayed antifungal activity against the reference C. albicans (MIC = 4 μM), Aspergilla niger (MIC = 32 μM), Aspergillus flavus (MIC = 8 μM), and Trichopyton rubrum (MIC = 16 μM). The effect of P7 on the C. albicans cell membrane was examined by investigating the calcein leakage from fungal membrane models made of egg yolk l-phosphatidylcholine/ergosterol (10 : 1, w/w) liposomes. P7 showed potent leakage effects against fungal liposomes similar to Melittin-treated cells. C. albicans protoplast regeneration assay demonstrated that P7 interacted with the C. albicans plasma membrane. Flow cytometry of the plasma membrane potential and integrity of C. albicans showed that P7 caused 60.9 ± 1.8% depolarization of the membrane potential of intact C. albicans cells and caused 58.1 ± 3.2% C. albicans cell membrane damage. Confocal laser scanning microscopy demonstrated that part of FITC-P7 accumulated in the cytoplasm. DNA retardation analysis was also performed, which showed that P7 interacted with C. albicans genomic DNA after penetrating the cell membrane, completely inhibiting the migration of genomic DNA above the weight ratio (peptide : DNA) of 6. Our results indicated that the plasma membrane was the primary target, and DNA was the secondary intracellular target of the mode of action of P7 against C. albicans. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27197902

  16. Comparison of the MUREX C. albicans, Albicans-Sure, and BactiCard Candida test kits with the germ tube test for presumptive identification of Candida albicans.

    OpenAIRE

    Crist, A E; Dietz, T J; Kampschroer, K.

    1996-01-01

    The MUREX C. albicans (MC)(Murex Diagnostics), Albicans-Sure (AS) (Clinical Standards Laboratories), and BactiCard Candida (BC) (Remel) test kits were compared with the germ tube (GT) test for the rapid, presumptive identification of Candida albicans. All three test kits detect the enzymes L-proline aminopeptidase and beta-galactosaminidase in yeast cells grown on culture media and are based on the principle that C. albicans produces both enzymes whereas other yeasts produce only one or neith...

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

    Science.gov (United States)

    Meiller, Timothy F; Hube, Bernhard; Schild, Lydia; Shirtliff, Mark E; Scheper, Mark A; Winkler, Robert; Ton, Amy; Jabra-Rizk, Mary Ann

    2009-01-01

    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 first defined

  18. 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

  19. Candida albicans and Candida parapsilosis induce different T-cell responses in human peripheral blood mononuclear cells

    NARCIS (Netherlands)

    Toth, A.; Csonka, K.; Jacobs, C.; Vagvolgyi, C.; Nosanchuk, J.D.; Netea, M.G.; Gacser, A.

    2013-01-01

    Candida parapsilosis is the third most frequent cause of candidemia. Despite its clinical importance, little is known about the human immunological response to C. parapsilosis. In this study, we compared the cytokine responses evoked by Candida albicans and C. parapsilosis. C. parapsilosis-stimulate

  20. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-07-01

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

  2. Evaluation of caries-associated virulence of biofilms from Candida albicans isolated from saliva of pediatric patients with sickle-cell anemia

    OpenAIRE

    Brighenti, Fernanda Lourenção; Amanda Coelho MEDEIROS; Bruno Mello MATOS; Zulene Eveline Abreu RIBEIRO; Cristiane Yumi KOGA-ITO

    2014-01-01

    A previous study demonstrated that the amount of Candida spp. in saliva is higher in children with sickle-cell disease. The results from a recent study demonstrate its participation in the etiology of dental caries. Objective This study assessed caries-associated virulence (production of acid, extracellular polysaccharides, proteins and metabolic activity) of biofilms from Candida albicans isolated from saliva of patients with sickle-cell anemia in comparison to isolates obtained from matc...

  3. Deletion of ALS5, ALS6 or ALS7 increases adhesion of Candida albicans to human vascular endothelial and buccal epithelial cells

    OpenAIRE

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

    2007-01-01

    C. albicans yeast forms deleted for ALS5, ALS6 or ALS7 are more adherent than a relevant control strain to human vascular endothelial cell monolayers and buccal epithelial cells. In the buccal and vaginal reconstituted human epithelium (RHE) disease models, however, mutant and control strains caused a similar degree of tissue destruction. Deletion of ALS5 or ALS6 significantly slowed growth of the mutant strain; this phenotype was not affected by addition of excess uridine to the culture medi...

  4. Secretion, interaction and assembly of two O-glycosylated cell wall antigens from Candida albicans.

    Science.gov (United States)

    Pavia, J; Aguado, C; Mormeneo, S; Sentandreu, R

    2001-07-01

    The mechanisms of incorporation of two antigens have been determined using a monoclonal antibody (3A10) raised against the material released from the mycelial cell wall by zymolyase digestion and retained on a concanavalin A column. One of the hybridomas secreted an IgG that reacted with two bands in Western blots. Indirect immunofluorescence showed that the antigens were located on the surfaces of mycelial cells, but within the cell walls of yeasts. These antigens were detected in a membrane preparation, in the SDS-soluble material and in the material released by a 1,3-beta-glucanase and chitinase from the cell walls of yeast and mycelial cells. In the latter three samples, an additional high-molecular-mass, highly polydispersed band was also detected. Beta-elimination of each fraction resulted in the disappearance of all antigen bands, suggesting that they are highly O-glycosylated. In addition, the electrophoretic mobility of the high-molecular-mass, highly polydispersed bands increased after digestion with endoglycosidase H, indicating that they are also N-glycosylated. New antigen bands were released when remnants of the cell walls extracted with 1,3-beta-glucanase or chitinase were digested with chitinase or 1,3-beta-glucanase. These results are consistent with the notion that, after secretion, parts of the O-glycosylated antigen molecules are transferred to an N-glycosylated protein(s). This molecular complex, as well as the remaining original 70 and 80 kDa antigen molecules, next bind to 1,3-beta-glucan or chitin, probably via 1,6-beta-glucan, and, in an additional step, to chitin or 1,3-beta-glucan. This process results in the final molecular product of each antigen, and their distribution in the cell walls. PMID:11429475

  5. The conserved dual phosphorylation sites of the Candida albicans Hog1 protein are crucial for white-opaque switching, mating, and pheromone-stimulated cell adhesion.

    Science.gov (United States)

    Chang, Wen-Han; Liang, Shen-Huan; Deng, Fu-Sheng; Lin, Ching-Hsuan

    2016-08-01

    Candida albicans is an opportunistic human pathogen capable of causing life-threatening infections in immunocompromised patients. C. albicans has a unique morphological transition between white and opaque phases. These two cells differ in virulence, mating capability, biofilm formation, and host-cell interaction. Previous studies revealed that deletion of the SSK2, PBS2, or HOG1 gene resulted in 100% opaque cell formation and suppressed the mating response. Thr-174 and Tyr-176 of the Hog1 protein are important phosphoacceptors and can be activated in response to stimuli. In this study, we first demonstrated the importance of two conserved phosphorylation sites in white-opaque switching, mating, and pheromone-stimulated cell adhesion. Six Hog1 point-mutated strains were generated, including nonphosphorylated strains (Hog1(T174A), Hog1(Y176F), and Hog1(T174A,Y176F)) and negatively charged phosphorylated strains (Hog1(T174D), Hog1(Y176D), and Hog1(T174D,Y176D)). Point mutation on Thr-174, Tyr-176 or in combination with the Hog1 protein in C. albicans MTL homozygous strains stimulated opaque cell formation at a frequency of 100%. Furthermore, mating projections of point-mutated strains were significantly shorter and their mating efficiencies and pheromone-stimulated cell adhesive numbers were lower than those of the wild-type. By investigating the effects of Hog1 phosphorylation in ssk1Δ and sln1Δ, we also demonstrate that the phosphorylation intensity of Hog1p is directly involved in the white-opaque switching. Taken together, the results of our study demonstrate that dual phosphorylation sites of C. albicans are crucial for white-opaque transition, sexual mating, and pheromone-induced cell adhesion. PMID:27118797

  6. 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...... 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...

  7. Cell cycle-independent phospho-regulation of Fkh2 during hyphal growth regulates Candida albicans pathogenesis.

    Directory of Open Access Journals (Sweden)

    Jamie A Greig

    2015-01-01

    Full Text Available The opportunistic human fungal pathogen, Candida albicans, undergoes morphological and transcriptional adaptation in the switch from commensalism to pathogenicity. Although previous gene-knockout studies have identified many factors involved in this transformation, it remains unclear how these factors are regulated to coordinate the switch. Investigating morphogenetic control by post-translational phosphorylation has generated important regulatory insights into this process, especially focusing on coordinated control by the cyclin-dependent kinase Cdc28. Here we have identified the Fkh2 transcription factor as a regulatory target of both Cdc28 and the cell wall biosynthesis kinase Cbk1, in a role distinct from its conserved function in cell cycle progression. In stationary phase yeast cells 2D gel electrophoresis shows that there is a diverse pool of Fkh2 phospho-isoforms. For a short window on hyphal induction, far before START in the cell cycle, the phosphorylation profile is transformed before reverting to the yeast profile. This transformation does not occur when stationary phase cells are reinoculated into fresh medium supporting yeast growth. Mass spectrometry and mutational analyses identified residues phosphorylated by Cdc28 and Cbk1. Substitution of these residues with non-phosphorylatable alanine altered the yeast phosphorylation profile and abrogated the characteristic transformation to the hyphal profile. Transcript profiling of the phosphorylation site mutant revealed that the hyphal phosphorylation profile is required for the expression of genes involved in pathogenesis, host interaction and biofilm formation. We confirmed that these changes in gene expression resulted in corresponding defects in pathogenic processes. Furthermore, we identified that Fkh2 interacts with the chromatin modifier Pob3 in a phosphorylation-dependent manner, thereby providing a possible mechanism by which the phosphorylation of Fkh2 regulates its

  8. 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. PMID:24224742

  9. Genetics of Candida albicans.

    OpenAIRE

    Scherer, S.; Magee, P T

    1990-01-01

    Candida albicans is among the most common fungal pathogens. Infections caused by C. albicans and other Candida species can be life threatening in individuals with impaired immune function. Genetic analysis of C. albicans pathogenesis is complicated by the diploid nature of the species and the absence of a known sexual cycle. Through a combination of parasexual techniques and molecular approaches, an effective genetic system has been developed. The close relationship of C. albicans to the more...

  10. Differentiation by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) of Candida albicans isolated from upper respiratory tract in patients with non-small cell lung cancer.

    Science.gov (United States)

    Biernasiuk, Anna; Korona-Głowniak, Izabela; Grzegorczyk, Agnieszka; Malm, Anna

    2014-01-01

    Cancer patients are predisposed to fungal infections caused by Candida albicans, especially to oral or respiratory tract candidiasis. The aim of this study was to estimate genetic diversity by RAPD-PCR (random amplified polymorphic DNA-polymerase chain reaction) of C. albicans isolated from upper respiratory tract of 100 patients with non-small cell lung cancer. Among 52 strains, 34 genotypes were defined. 10 clusters comprising 28 (53.85%) isolates with similarity coefficient ≥ 80% were formed. The remaining 24 (46.15%) isolates represented individual genotypes. The RAPD-PCR technique revealed genomic variability within C. albicans isolated from upper respiratory tract of the cancer patients. PMID:25371918

  11. Candida Albicans

    OpenAIRE

    Dr. Maria Magdalena Simatupang

    2009-01-01

    義歯性口内炎患者のデンチャープラーク中には、多数の真菌が認められることから、これら真菌が衰症の原因菌の一つとされている。このようなデンチャープラーク中の真菌には、Candida属が高頻度に検出され、中でもCandida albicansの検出率が著しく高いことが知られている。本真菌は、酵母(Y)型並びにフィラメント(F)型の二つの形態をとる二形性真菌であり、種々の因子によりその形態が変化することが、古くから知られている。しかし、その詳細な機構については未だ不明な点が多い。著者は、C.albicansが培地中のビオテン濃度により形態変化を受ける事実に着目し、本菌の二形性と脂質代謝との間に、なんらかの関連性があるのではないかとの作業仮設のもとに、以下の実験を行った。 本研究は、Candida albicans A IFO 1385株を用いて行った。使用培地は、サブローグルコース培地(2% グルコース、1% ペプトン、 0.5% イーストエキス)(medium A)並びにメチオニン含有合成培地(medium B)である。培養温度は、それぞれY型薗並びにF型菌を得るために、25℃...

  12. Candida albicans Biofilm-Defective Mutants

    OpenAIRE

    Richard, Mathias L.; Nobile, Clarissa J.; Bruno, Vincent M; Mitchell, Aaron P.

    2005-01-01

    Biofilm formation plays a key role in the life cycles and subsistence of many microorganisms. For the human fungal pathogen Candida albicans, biofilm development is arguably a virulence trait, because medical implants that serve as biofilm substrates are significant risk factors for infection. The development of C. albicans biofilms in vitro proceeds through an early phase, in which yeast cells populate a substrate, an intermediate phase, in which pseudohyphal and hyphal cell types are produc...

  13. Candida albicans Cas5, a Regulator of Cell Wall Integrity, Is Required for Virulence in Murine and Toll Mutant Fly Models

    OpenAIRE

    Chamilos, Georgios; Nobile, Clarissa J.; Bruno, Vincent M.; Lewis, Russell E.; Mitchell, Aaron P.; Kontoyiannis, Dimitrios P.

    2009-01-01

    Candida albicans is the most common human fungal pathogen, yet the pathogenesis of C. albicans infection remains incompletely understood. We hypothesized that C. albicans has developed evolutionarily conserved mechanisms to invade disparate hosts and tested whether Toll mutant flies could serve as a model host for high-throughput screening of C. albicans virulence genes. We screened 34 C. albicans mutants defective in putative transcription factor genes (see http://www.tigr.org/tigr-scripts/e...

  14. Role of Glucosyltransferase B in Interactions of Candida albicans with Streptococcus mutans and with an Experimental Pellicle on Hydroxyapatite Surfaces ▿ †

    Science.gov (United States)

    Gregoire, S.; Xiao, J.; Silva, B. B.; Gonzalez, I.; Agidi, P. S.; Klein, M. I.; Ambatipudi, K. S.; Rosalen, P. L.; Bauserman, R.; Waugh, R. E.; Koo, H.

    2011-01-01

    Candida albicans and mutans streptococci are frequently detected in dental plaque biofilms from toddlers afflicted with early childhood caries. Glucosyltransferases (Gtfs) secreted by Streptococcus mutans bind to saliva-coated apatite (sHA) and to bacterial surfaces, synthesizing exopolymers in situ, which promote cell clustering and adherence to tooth enamel. We investigated the potential role Gtfs may play in mediating the interactions between C. albicans SC5314 and S. mutans UA159, both with each other and with the sHA surface. GtfB adhered effectively to the C. albicans yeast cell surface in an enzymatically active form, as determined by scintillation spectroscopy and fluorescence imaging. The glucans formed on the yeast cell surface were more susceptible to dextranase than those synthesized in solution or on sHA and bacterial cell surfaces (P mutans cells bound to C. albicans cells with glucans present on their surface than to yeast cells without surface glucans (uncoated). The glucans formed in situ also enhanced C. albicans interactions with sHA, as determined by a novel single-cell micromechanical method. Furthermore, the presence of glucan-coated yeast cells significantly increased the accumulation of S. mutans on the sHA surface (versus S. mutans incubated alone or mixed with uncoated C. albicans; P mutans on the tooth enamel surface, thereby modulating the development of virulent biofilms. PMID:21803906

  15. Cell Wall N-Linked Mannoprotein Biosynthesis Requires Goa1p, a Putative Regulator of Mitochondrial Complex I in Candida albicans

    OpenAIRE

    She, Xiaodong; Calderone, Richard; Kruppa, Michael; Lowman, Douglas; Williams, David; Zhang, Lili; Gao, Ying; Khamooshi, Kasra; Liu, Weida; Li, Dongmei

    2016-01-01

    The Goa1p of Candida albicans regulates mitochondrial Complex I (CI) activities in its role as a putative CI accessory protein. Transcriptional profiling of goa1∆ revealed a down regulation of genes encoding β-oligomannosyl transferases. Herein, we present data on cell wall phenotypes of goa1∆ (strain GOA31). We used transmission electron microscopy (TEM), GPC/MALLS, and NMR to compare GOA31 to a gene-reconstituted strain (GOA32) and parental cells. We note by TEM a reduction in outer wall fi...

  16. Candida albicans Quorum Sensing Molecules Stimulate Mouse Macrophage Migration

    OpenAIRE

    Hargarten, Jessica C.; Moore, Tyler C.; Petro, Thomas M.; Nickerson, Kenneth W.; Atkin, Audrey L.

    2015-01-01

    The polymorphic commensal fungus Candida albicans causes life-threatening disease via bloodstream and intra-abdominal infections in immunocompromised and transplant patients. Although host immune evasion is a common strategy used by successful human fungal pathogens, C. albicans provokes recognition by host immune cells less capable of destroying it. To accomplish this, C. albicans white cells secrete a low-molecular-weight chemoattractive stimulant(s) of macrophages, a phagocyte that they ar...

  17. Inhibition of human natural killer (NK) cytotoxicity by Candida albicans

    International Nuclear Information System (INIS)

    Experiments were initiated to determine whether human NK cells are cytotoxic to C. albicans with similar activity observed for mouse NK cells against the yeast Paracoccidiodes brasiliensis. In 48 hour assays using limiting dilutions of C. albicans, strain 3153A, mononuclear leukocytes with NK activity had only marginal effects on yeast outgrowth, whereas granulocytes killed most of the yeast. However, these yeast were able to block NK activity in 4 hr 51Cr release assays with K562 cells, at yeast to K562 ratios of 10:1 and 100:1. Yeast pretreated with the serum of the majority of donors blocked the NK activity more than untreated yeast. Two of the 7 donors did not enhance NK inhibition after pretreatment of the yeast with their serum. Serum antibody to C. albicans and complement consumption by the yeast correlated with the relative efficiency of NK inhibition for most donors. This report suggests that there may be in vivo interactions between NK cells of the immune system and opportunistic fungal pathogens, which may compromise NK cell function

  18. Cell Cycle-Independent Phospho-Regulation of Fkh2 during Hyphal Growth Regulates Candida albicans Pathogenesis

    OpenAIRE

    Greig, Jamie A.; Sudbery, Ian M; Richardson, Jonathan; Naglik, Julian; Wang, Yue; Sudbery, Peter E.

    2015-01-01

    The opportunistic human fungal pathogen, Candida albicans, undergoes morphological and transcriptional adaptation in the switch from commensalism to pathogenicity. Although previous gene-knockout studies have identified many factors involved in this transformation, it remains unclear how these factors are regulated to coordinate the switch. Investigating morphogenetic control by post-translational phosphorylation has generated important regulatory insights into this process, especially focusi...

  19. Cell cycle-independent phospho-regulation of Fkh2 during hyphal growth regulates Candida albicans pathogenesis.

    OpenAIRE

    Greig, Jamie A.; Sudbery, Ian M; Richardson, Jonathan P; Naglik, Julian R.; Yue Wang; Sudbery, Peter E.

    2015-01-01

    The opportunistic human fungal pathogen, Candida albicans, undergoes morphological and transcriptional adaptation in the switch from commensalism to pathogenicity. Although previous gene-knockout studies have identified many factors involved in this transformation, it remains unclear how these factors are regulated to coordinate the switch. Investigating morphogenetic control by post-translational phosphorylation has generated important regulatory insights into this process, especially focusi...

  20. The Cnh1 antiporter is important for potassium and pH homeostasis in C. albicans cells

    Czech Academy of Sciences Publication Activity Database

    Zimmermannová, Olga; Sychrová, Hana

    Bratislava : SAV, 2006. s. 81-81. ISSN 1336-4839. [Annual Conference on Yeasts /34./. 10.05.2006-12.05.2006, Smolenice] R&D Projects: GA MŠk(CZ) LC531 Keywords : Candida albicans * Cnh1 antiporter * potassium homeostasis * intracellular pH Subject RIV: EB - Genetics ; Molecular Biology

  1. Proinflammatory Chemokines during Candida albicans Keratitis

    OpenAIRE

    Yuan, Xiaoyong; Hua, Xia; Wilhelmus, Kirk R.

    2009-01-01

    Chemotactic cytokines mediate the recruitment of leukocytes into infected tissues. This study investigated the profile of chemokines during experimental Candida albicans keratitis and determined the effects of chemokine inhibition on leukocyte infiltration and fungal growth during murine keratomycosis. Scarified corneas of BALB/c mice were topically inoculated with C. albicans and monitored daily over one week for fungal keratitis. After a gene microarray for murine chemokines compared infect...

  2. 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.

  3. Antifungal activity of clotrimazole against Candida albicans depends on carbon sources, growth phase and morphology.

    Science.gov (United States)

    Kasper, Lydia; Miramón, Pedro; Jablonowski, Nadja; Wisgott, Stephanie; Wilson, Duncan; Brunke, Sascha; Hube, Bernhard

    2015-07-01

    Vulvovaginal candidiasis, a superficial infection caused predominantly by the pathogenic fungus Candida albicans, is frequently treated with clotrimazole. Some drug formulations contain lactate for improved solubility. Lactate may modify C. albicans physiology and drug sensitivity by serving as a carbon source for the fungus and/or affecting local pH. Here, we explored the effects of lactate, in combination with pH changes, on C. albicans proliferation, morphology and clotrimazole sensitivity. Moreover, we determined the influence of growth phase and morphology per se on drug sensitivity. We showed that utilization of lactate as a carbon source did not promote fast fungal proliferation or filamentation. Lactate had no influence on clotrimazole-mediated killing of C. albicans in standard fungal cultivation medium but had an additive effect on the fungicidal clotrimazole action under in vitro vagina-simulative conditions. Moreover, clotrimazole-mediated killing was growth-phase and morphology dependent. Post-exponential cells were resistant to the fungicidal action of clotrimazole, whilst logarithmic cells were sensitive, and hyphae showed the highest susceptibility. Finally, we showed that treatment of pre-formed C. albicans hyphae with sublethal concentrations of clotrimazole induced a reversion to yeast-phase growth. As C. albicans hyphae are considered the pathogenic morphology during mucosal infections, these data suggest that elevated fungicidal activity of clotrimazole against hyphae plus clotrimazole-induced hyphae-to-yeast reversion may help to dampen acute vaginal infections by reducing the relative proportion of hyphae and thus shifting to a non-invasive commensal-like population. In addition, lactate as an ingredient of clotrimazole formulations may potentiate clotrimazole killing of C. albicans in the vaginal microenvironment. PMID:25976001

  4. Preparation of Candida albicans Biofilms for Transmission Electron Microscopy

    OpenAIRE

    Taff, Heather T.; Andes, David R.

    2013-01-01

    Transmission Electron Microscopy is a form of microscopy that allows for imaging of distinct portions of an individual cell. For Candida albicans biofilms, it is often used to visualize the cell walls of fixed samples of yeast and hyphae. This protocol describes how to grow, harvest, and fix Candida albicans biofilms in preparation for Transmission Electron Microscopy.

  5. Endoftalmite por Candida albicans Candida albicans endophthalmitis

    OpenAIRE

    Pedro Duraes Serracarbassa; Patrícia Dotto

    2003-01-01

    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 f...

  6. Endoftalmite por Candida albicans Candida albicans endophthalmitis

    Directory of Open Access Journals (Sweden)

    Pedro Duraes Serracarbassa

    2003-10-01

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

  7. Non-lytic expulsion/exocytosis of Candida albicans from macrophages

    OpenAIRE

    Bain, Judith M.; Lewis, Leanne E.; Okai, Blessing; Quinn, Janet; Gow, Neil A R; Erwig, Lars-Peter

    2012-01-01

    Candida albicans is an opportunistic pathogen and is recognised and phagocytosed by macrophages. Using live-cell imaging, non-lytic expulsion/exocytosis of C. albicans from macrophages is demonstrated for the first time. Following complete expulsion, both the phagocyte and pathogen remain intact and viable. Partial engulfment of hyphal C. albicans without macrophage lysis is also demonstrated. These observations underpin the complexity of interactions between C. albicans and innate immune cells.

  8. Pleiotropic effects of the vacuolar ABC transporter MLT1 of Candida albicans on cell function and virulence.

    Science.gov (United States)

    Khandelwal, Nitesh Kumar; Kaemmer, Philipp; Förster, Toni M; Singh, Ashutosh; Coste, Alix T; Andes, David R; Hube, Bernhard; Sanglard, Dominique; Chauhan, Neeraj; Kaur, Rupinder; d'Enfert, Christophe; Mondal, Alok Kumar; Prasad, Rajendra

    2016-06-01

    Among the several mechanisms that contribute to MDR (multidrug resistance), the overexpression of drug-efflux pumps belonging to the ABC (ATP-binding cassette) superfamily is the most frequent cause of resistance to antifungal agents. The multidrug transporter proteins Cdr1p and Cdr2p of the ABCG subfamily are major players in the development of MDR in Candida albicans Because several genes coding for ABC proteins exist in the genome of C. albicans, but only Cdr1p and Cdr2p have established roles in MDR, it is implicit that the other members of the ABC family also have alternative physiological roles. The present study focuses on an ABC transporter of C. albicans, Mlt1p, which is localized in the vacuolar membrane and specifically transports PC (phosphatidylcholine) into the vacuolar lumen. Transcriptional profiling of the mlt1∆/∆ mutant revealed a down-regulation of the genes involved in endocytosis, oxidoreductase activity, virulence and hyphal development. High-throughput MS-based lipidome analysis revealed that the Mlt1p levels affect lipid homoeostasis and thus lead to a plethora of physiological perturbations. These include a delay in endocytosis, inefficient sequestering of reactive oxygen species (ROS), defects in hyphal development and attenuated virulence. The present study is an emerging example where new and unconventional roles of an ABC transporter are being identified. PMID:27026051

  9. [Determination of the antimicrobial capacity of green tea (Camellia sinensis) against the potentially pathogenic microorganisms Escherichia coli, Salmonella enterica, Staphylococcus aureus, Listeria monocytogenes, Candida albicans and Aspergillus niger].

    Science.gov (United States)

    Mora, Andreína; Pawa, Jonathan; Chaverri, José M; Arias, María Laura

    2013-09-01

    Many studies can be found in scientific literature demonstrating the antimicrobial capacity of different herbs, including green tea. Never-theless, many results are divergent or cannot be compared. Several green tea formulations may be found in market, but there is scarce or non-information about its activity. In this work, the potential antimicrobial effect of 50 samples of dry green tea and in 10% infusion against Escherichia coli, Salmonella enterica, Listeria monocytogenes, Staphylococcus aureus, Candida albicans and Aspergillus niger distributed in the metropolitan area of Costa Rica, was determined. This activity was compared with the effect produced by Chinese origin green tea (Camellia sinensis). Different solvents were evaluated for preparing polyphenol enriched extracts from green tea samples. Total phenols were determined using the Folin-Ciocalteu spectrophotometric methodology, using galic acid as reference. Antimicrobial activity of green tea extracts and infusions was evaluated using the microplate methodology described by Breuking (2006). Ethanol was the most efficient solvent used for the polyphenol extractions. There was no antimicrobial effect of the different green tea extracts and infusions against the microorganisms evaluated, except for Listeria monocytogenes, where the extracts of 70% of samples analyzed and the control showed an inhibitory effect in the 10.5 mg/mL and 1.05 mg/L concentrations. None of the infusions tested, including the control, showed any effect against this bacteria. PMID:25362825

  10. The putative ABC transporter encoded by the orf19.4531 plays a role in the sensitivity of Candida albicans cells to azole antifungal drugs.

    Science.gov (United States)

    Jiang, Linghuo; Xu, Dayong; Chen, Zhen; Cao, Yongbing; Gao, Pinghui; Jiang, Yuanying

    2016-05-01

    ATP-binding cassette (ABC) transporters constitute a large superfamily of integral membrane proteins in prokaryotic and eukaryotic cells. In the human fungal pathogenCandida albicans, there are 28 genes encoding ABC transporters and many of them have not been characterized so far. The orf19.4531 (also known as IPF7530) encodes a putative ABC transporter. In this study, we have demonstrated that disruption of orf19.4531 causesC. albicanscells to become tolerant to azoles, but not to polyene antifungals and terbinafine. Therefore, the protein encoded by orf19.4531 is involved in azole sensitivity and we name it asROA1, the regulator of azole sensitivity 1 gene. Consistently, we show that the expression ofROA1is responsive to treatment of either fluconazole or ketoconazole inC. albicans In addition, through a GFP tagging approach, Roa1 is localized in a small punctuate compartment adjacent to the vacuolar membrane. However,ROA1is not essential for thein vitrofilamentation ofC. albicanscells. PMID:26975389

  11. 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.

  12. Purification of actin from Candida albicans and comparison with the Candida 48,000-Mr protein.

    OpenAIRE

    Fiss, E.; Buckley, H R

    1987-01-01

    Actin was purified from Candida albicans cells by affinity chromatography by DNase-Sepharose and was recognized by immunoblotting with monoclonal antibody directed against chick muscle actin. The C. albicans 48-kilodalton protein recognized by sera from patients with invasive candidiasis was shown by DEAE chromatography and immunoblotting not to be identical with the purified C. albicans actin.

  13. In vitro antifungal activity of dictamnine against candida albicans%白鲜碱对白色念珠菌体外抑制作用初探

    Institute of Scientific and Technical Information of China (English)

    施琳俊; 薛婷君; 吴岚; 朱彩莲; 周曾同

    2011-01-01

    目的:检测白鲜碱对白色念珠菌的抑制作用,及其对白色念珠菌细胞周期的影响.方法:采用白色念珠菌标准菌株(ATCC76615)为研究对象,用经典方法测定白鲜碱对白色念珠菌的最小抑菌浓度(MIC),抑制生物膜50%(SMIC50)的药物浓度,流式细胞仪分析白鲜碱对白色念珠菌细胞周期的影响.结果:白鲜碱对白色念珠菌的MIC为312.5 μg/mL,对生物膜的SMIC50为1250 μg/mL,白鲜碱能使白色念珠菌生长停滞.结论:白鲜碱具有抑制白色念珠菌生长的能力.%Objective:To investigate the in vitro antifungal activity of dictamnine against Candida albicans and the in-fluence of dictamnine on the cell cycle of Candida albicans. Method: NCCLS M27-A2 broth microdilution method was ac-cessed to evaluate the in vitro activity of dictamnine against Candida albicans (ATCC 76615). XTT-reduction method was used to test the SMIC50 of dictamnine against Candida albicans biofilms. Flow cytometer was applied to determine the effect of dictamnine on the cell cycle of Candida albicans. Result: MIC of dictamnine against Candida albicans was 312.5 μg / mL. SMIC50 of dictamnine against Candida albicans biofilms was 1250 μg / mL. Dictamnine can stop the growth cycle of Candi-da albicans. Conclusion: Dictamnine displayed in vitro antifungal activity against Candida albicans.

  14. Comparison of the Hydrophobic Properties of Candida albicans and Candida dubliniensis

    OpenAIRE

    Hazen, Kevin C.; Wu, Jean G.; Masuoka, James

    2001-01-01

    Although Candida dubliniensis is a close genetic relative of Candida albicans, it colonizes and infects fewer sites. Nearly all instances of candidiasis caused by C. dubliniensis are restricted to the oral cavity. As cell surface hydrophobicity (CSH) influences virulence of C. albicans, CSH properties of C. dubliniensis were investigated and compared to C. albicans. Growth temperature is one factor which affects the CSH status of stationary-phase C. albicans. However, C. dubliniensis, similar...

  15. Traversal of Candida albicans across Human Blood-Brain Barrier In Vitro

    OpenAIRE

    Jong, Ambrose Y.; Stins, Monique F.; Huang, Sheng-He; Chen, Steven H. M.; Kim, Kwang Sik

    2001-01-01

    Candida albicans is an opportunistic pathogen, which primarily affects neonates and immunocompromised individuals. The pathogen can invade the central nervous system, resulting in meningitis. At present, the pathogenesis of C. albicans meningitis is unclear. We used an in vitro model of the human blood-brain barrier to investigate the interaction(s) of C. albicans with human brain microvascular endothelial cells (BMEC). Binding of C. albicans to human BMEC was time and inoculum dependent. Inv...

  16. Mitochondrial two-component signaling systems in Candida albicans.

    Science.gov (United States)

    Mavrianos, John; Berkow, Elizabeth L; Desai, Chirayu; Pandey, Alok; Batish, Mona; Rabadi, Marissa J; Barker, Katherine S; Pain, Debkumar; Rogers, P David; Eugenin, Eliseo A; Chauhan, Neeraj

    2013-06-01

    Two-component signal transduction pathways are one of the primary means by which microorganisms respond to environmental signals. These signaling cascades originated in prokaryotes and were inherited by eukaryotes via endosymbiotic lateral gene transfer from ancestral cyanobacteria. We report here that the nuclear genome of the pathogenic fungus Candida albicans contains elements of a two-component signaling pathway that seem to be targeted to the mitochondria. The C. albicans two-component response regulator protein Srr1 (stress response regulator 1) contains a mitochondrial targeting sequence at the N terminus, and fluorescence microscopy reveals mitochondrial localization of green fluorescent protein-tagged Srr1. Moreover, phylogenetic analysis indicates that C. albicans Srr1 is more closely related to histidine kinases and response regulators found in marine bacteria than are other two-component proteins present in the fungi. These data suggest conservation of this protein during the evolutionary transition from endosymbiont to a subcellular organelle. We used microarray analysis to determine whether the phenotypes observed with a srr1Δ/Δ mutant could be correlated with gene transcriptional changes. The expression of mitochondrial genes was altered in the srr1Δ/Δ null mutant in comparison to their expression in the wild type. Furthermore, apoptosis increased significantly in the srr1Δ/Δ mutant strain compared to the level of apoptosis in the wild type, suggesting the activation of a mitochondrion-dependent apoptotic cell death pathway in the srr1Δ/Δ mutant. Collectively, this study shows for the first time that a lower eukaryote like C. albicans possesses a two-component response regulator protein that has survived in mitochondria and regulates a subset of genes whose functions are associated with the oxidative stress response and programmed cell death (apoptosis). PMID:23584995

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

    Science.gov (United States)

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

    2007-03-01

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

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

    International Nuclear Information System (INIS)

    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 Ca2+–Mg2+ ATPase in C. albicans. • Baicalin increases the endocytic free Ca2+ 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 3H-UdR, 3H-TdR and 3H-leucine incorporation into C. albicans using the isotope incorporation technology. The activities of Succinate Dehydrogenase (SDH), cytochrome oxidase (CCO) and Ca2+–Mg2+ ATPase, cytosolic Ca2+ concentration, the cell cycle and apoptosis, as well as the ultrastructure of C.albicans were also tested. We found that baicalin inhibited 3H-UdR, 3H-TdR and 3H-leucine incorporation into C.albicans (P < 0.005). The activities of the SDH and Ca2+–Mg2+ ATPase of C.albicans in baicalin groups were lower than those in control group (P < 0.05). Ca2+ 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 Ca2+–Mg2+ ATPase, increasing cytosolic Ca2+ content and damaging the ultrastructure of C. albicans

  19. 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

  20. Inactivation of α1-proteinase inhibitor by Candida albicans aspartic proteases favors the epithelial and endothelial cell colonization in the presence of neutrophil extracellular traps.

    Science.gov (United States)

    Gogol, Mariusz; Ostrowska, Dominika; Klaga, Kinga; Bochenska, Oliwia; Wolak, Natalia; Aoki, Wataru; Ueda, Mitsuyoshi; Kozik, Andrzej; Rapala-Kozik, Maria

    2016-01-01

    Candida albicans, a causative agent of opportunistic fungal infections in immunocompromised patients, uses ten secreted aspartic proteases (SAPs) to deregulate the homeostasis of the host organism on many levels. One of these deregulation mechanisms involves a SAP-dependent disturbance of the control over proteolytic enzymes of the host by a system of dedicated proteinase inhibitors, with one important example being the neutrophil elastase and alpha1-proteinase inhibitor (A1PI). In this study, we found that soluble SAPs 1-4 and the cell membrane-anchored SAP9 efficiently cleaved A1PI, with the major cleavage points located at the C-terminal part of A1PI in a close vicinity to the reactive-site loop that plays a critical role in the inhibition mechanism. Elastase is released by neutrophils to the environment during fungal infection through two major processes, a degranulation or formation of neutrophil extracellular traps (NET). Both, free and NET-embedded elastase forms, were found to be controlled by A1PI. A local acidosis, resulting from the neutrophil activity at the infection sites, favors A1PI degradation by SAPs. The deregulation of NET-connected elastase affected a NET-dependent damage of epithelial and endothelial cells, resulting in the increased susceptibility of these host cells to candidal colonization. Moreover, the SAP-catalyzed cleavage of A1PI was found to decrease its binding affinity to a proinflammatory cytokine, interleukin-8. The findings presented here suggest a novel strategy used by C. albicans for the colonization of host tissues and overcoming the host defense. PMID:26641639

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

    Institute of Scientific and Technical Information of China (English)

    Tularat Sookto; Theerathavaj Srithavaj; Sroisiri Thaweboon; Boonyanit Thaweboon; Binit Shrestha

    2013-01-01

    Objective: To determine the anticandidal activities of Salvia officinalis L. (S. officinalis) essential oil against Candida albicans (C. albicans) and the inhibitory effects on the adhesion of C. albicans to polymethyl methacrylate (PMMA) resin surface. Methods: Disc diffusion method was first used to test the anticandidal activities of the S. officinalis L. essential oil against the reference strain (ATCC 90028) and 2 clinical strains of C. albicans. Then the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were determined by modified membrane method. The adhesion of C. albicans to PMMA resin surface was assessed after immersion with S. officinalis L. essential oil at various concentrations of 1×MIC, 0.5×MIC and 0.25×MIC at room temperature for 30 min. One-way ANOVA was used to compare the Candida cell adhesion with the pretreatment agents and Tukey’s test was used for multiple comparisons. Results: S. officinalis L. essential oil exhibited anticandidal activity against all strains of C. albicans with inhibition zone ranging from 40.5 mm to 19.5 mm. The MIC and MLC of the oil were determined as 2.780 g/L against all test strains. According to the effects on C. albicans adhesion to PMMA resin surface, it was found that immersion in the essential oil at concentrations of 1×MIC (2.780 g/L), 0.5×MIC (1.390 g/L) and 0.25×MIC (0.695 g/L) for 30 min significantly reduced the adhesion of all 3 test strains to PMMA resin surface in a dose dependent manner (P<0.05). Conclusions: S. officinalis L. essential oil exhibited anticandidal activities against C. albicans and had inhibitory effects on the adhesion of the cells to PMMA resin surface. With further testing and development, S. officinalis essential oil may be used as an antifungal denture cleanser to prevent candidal adhesion and thus reduce the risk of candida-associated denture stomatitis.

  2. 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.

  3. Influência da co-agregação entre Candida. albicans e Lactobacillus acidophilus na capacidade de adesão destes microrganismos às células epiteliais vaginais humanas (CEVH = Influence of the co-aggregation between Candida. albicans e Lactobacillus acidophilus on the adhesion capacity these microorganisms in the human ephitelial vaginal cells (HEVC

    Directory of Open Access Journals (Sweden)

    Simone Américo Etgeton

    2011-07-01

    Full Text Available Este trabalho teve por objetivo avaliar a influência da co-agregação in vitro entre Candida albicans e Lactobacillus acidophilus na capacidade de adesão destes microrganismos às células epiteliais vaginais humanas (CEVH. Foram utilizados um isolado vaginal de C. albicans e uma cepa ATCC de L. acidophilus. Uma suspensão de cada microrganismo isoladamente e do coagregado foram incubados com as CEVH obtidas de uma doadora saudável. Foram feitos esfregaços por cristal violeta e Papanicolaou, e o número de leveduras, lactobacilos ou coagregados aderidos às células foi contado (em 300 células superficiais-CS e 300 intermediárias-CI. A Microscopia eletrônica de varredura (MEV foi realizada em todas as situações dos ensaios.Leveduras e lactobacilos aderiram fortemente as CEVH, tanto em CS quanto em CI. A coagregação levou a um aumento na capacidade de adesão das leveduras (p 0,05. Havendo correlação com o que acontece in vivo, probióticos à base de L. acidophillus e mesmo uma flora lactobacilar vaginal não surtiriam efeito protetor contra a adesão de C. albicans as CEVH e do possível desenvolvimento de candidíase vulvovaginal.This work has aimed to evaluate the influence of the L. acidophilus and Candida albicans co-aggregation on the adhesion capacity this microorganisms in the human ephitelial vaginal cells (HEVC. One vaginal isolated of C. albicans and one ATCC strain of L. acidophilus was used. A suspension of the isolated and co-aggregated microorganisms was incubated with HVEC obtained from a healthy donor. After one hour, smears were made with crystal violet and Papanicolaou, and the number of yeasts adhered to HVEC was evaluated (300 superficial-SC and 300 intermediate cells-IC. Scanning electron microscopy (SEM was made in all situations of the assays. Yeasts and lactobacilli adhered strongly to the HEVC, both SC and IC. The co-aggregation there was an increase in the adhesion capacity of the yeasts (p 0

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

    Science.gov (United States)

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

    2013-01-01

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

  5. White-opaque switching in Candida albicans

    OpenAIRE

    Lohse, Matthew B.; Johnson, Alexander D.

    2009-01-01

    The human commensal yeast Candida albicans undergoes an epigenetic switch between two distinct types of cells, referred to as white and opaque. These two cell types differ in many respects, including their cell and colony morphologies, their metabolic states, their mating behaviors, their preferred niches in the host, and their interactions with the host immune system. Each of the two cell types is heritable for many generations and switching between them appears stochastic; however, environm...

  6. Antimicrobial evaluation of new metallic complexes with xylitol active against P. aeruginosa and C. albicans: MIC determination, post-agent effect and Zn-uptake.

    Science.gov (United States)

    Santi, E; Facchin, G; Faccio, R; Barroso, R P; Costa-Filho, A J; Borthagaray, G; Torre, M H

    2016-02-01

    Xylitol (xylH5) is metabolized via the pentose pathway in humans, but it is unsuitable as an energy source for many microorganisms where it produces a xylitol-induced growth inhibition and disturbance in protein synthesis. For this reason, xylitol is used in the prophylaxis of several infections. In the search of better antimicrobial agents, new copper and zinc complexes with xylitol were synthesized and characterized by analytical and spectrosco pic methods: Na2[Cu3(xylH−4)2]·NaCl·4.5H2O (Cu-xyl) and [Zn4(xylH−4)2(H2O)2]·NaCl·3H2O (Zn-xyl). Both copper and zinc complexes presented higher MIC against Pseudomona aeruginosa than the free xylitol while two different behaviors were found against Candida albicans depending on the complex. The growth curves showed that Cu-xyl presented lower activity than the free ligand during all the studied period. In the case of Znxyl the growth curves showed that the inhibition of the microorganism growth in the first stage was equivalent to that of xylitol but in the second stage (after 18 h) Zn-xyl inhibited more. Besides, the PAE (post agent effect)obtained for Zn-xyl and xyl showed that the recovery from the damage of microbial cells had a delay of 14 and 13 h respectively. This behavior could be useful in prophylaxis treatments for infectious diseases where it is important that the antimicrobial effect lasts longer. With the aim to understand the microbiological activities the analysis of the particle size, lipophilicity and Zn uptake was performed. PMID:26619097

  7. Farnesol-induced apoptosis in Candida albicans.

    Science.gov (United States)

    Shirtliff, Mark E; Krom, Bastiaan P; Meijering, Roelien A M; Peters, Brian M; Zhu, Jingsong; Scheper, Mark A; Harris, Megan L; Jabra-Rizk, Mary Ann

    2009-06-01

    Farnesol, a precursor in the isoprenoid/sterol pathway, was recently identified as a quorum-sensing molecule produced by the fungal pathogen Candida albicans. Farnesol is involved in the inhibition of germination and biofilm formation by C. albicans and can be cytotoxic at certain concentrations. In addition, we have shown that farnesol can trigger apoptosis in mammalian cells via the classical apoptotic pathways. In order to elucidate the mechanism behind farnesol cytotoxicity in C. albicans, the response to farnesol was investigated, using proteomic analysis. Global protein expression profiles demonstrated significant changes in protein expression resulting from farnesol exposure. Among the downregulated proteins were those involved in metabolism, glycolysis, protein synthesis, and mitochondrial electron transport and the respiratory chain, whereas proteins involved in folding, protection against environmental and oxidative stress, actin cytoskeleton reorganization, and apoptosis were upregulated. Cellular changes that accompany apoptosis (regulated cell death) were further analyzed using fluorescent microscopy and gene expression analysis. The results indicated reactive oxygen species accumulation, mitochondrial degradation, and positive terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) in the farnesol-exposed cells concurrent with increased expression of antioxidant-encoding and drug response genes. More importantly, the results demonstrated farnesol-induced upregulation of the caspase gene MCA1 and the intracellular presence of activated caspases. In conclusion, this study demonstrated that farnesol promotes apoptosis in C. albicans through caspase activation, implying an important physiological role for farnesol in the fungal cell life cycle with important implications for adaptation and survival. PMID:19364863

  8. Activation and binding of C3 by Candida albicans.

    OpenAIRE

    Kozel, T R; Brown, R R; Pfrommer, G S

    1987-01-01

    Interaction with components of the complement system is an important aspect of the pathogenesis of infection by Candida albicans. The key role of C3 as an opsonic ligand and as an element in amplification of complement activation led us to examine several factors that influence the activation and binding of C3 cleavage fragments to the yeast. Activation and binding of C3 were determined by use of normal human serum containing 125I-labeled C3. Incubation of yeast-phase cells in 20% serum led t...

  9. Global screening of potential Candida albicans biofilm-related transcription factors via network comparison

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    Murillo Luis A

    2010-01-01

    Full Text Available Abstract Background Candida albicans is a commonly encountered fungal pathogen in humans. The formation of biofilm is a major virulence factor in C. albicans pathogenesis and is related to antidrug resistance of this organism. Although many factors affecting biofilm have been analyzed, molecular mechanisms that regulate biofilm formation still await to be elucidated. Results In this study, from the gene regulatory network perspective, we developed an efficient computational framework, which integrates different kinds of data from genome-scale analysis, for global screening of potential transcription factors (TFs controlling C. albicans biofilm formation. S. cerevisiae information and ortholog data were used to infer the possible TF-gene regulatory associations in C. albicans. Based on TF-gene regulatory associations and gene expression profiles, a stochastic dynamic model was employed to reconstruct the gene regulatory networks of C. albicans biofilm and planktonic cells. The two networks were then compared and a score of relevance value (RV was proposed to determine and assign the quantity of correlation of each potential TF with biofilm formation. A total of twenty-three TFs are identified to be related to the biofilm formation; ten of them are previously reported by literature evidences. Conclusions The results indicate that the proposed screening method can successfully identify most known biofilm-related TFs and also identify many others that have not been previously reported. Together, this method can be employed as a pre-experiment screening approach that reveals new target genes for further characterization to understand the regulatory mechanisms in biofilm formation, which can serve as the starting point for therapeutic intervention of C. albicans infections.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. The interplay between NSAIDs and Candida albicans on the gastrointestinal tract of guinea pigs.

    Science.gov (United States)

    Nadăş, George C; Taulescu, Marian A; Ciobanu, Lidia; Fiţ, Nicodim I; Flore, Chirilă; Răpuntean, Sorin; Bouari, Cosmina M; Catoi, Cornel

    2013-04-01

    Recent studies suggest that Candida albicans colonization is associated with several gastrointestinal inflammatory disorders and is also responsible for the delay in ulcer healing. No data are reported about the effects of C. albicans on the nonsteroidal anti-inflammatory drugs (NSAIDs)-induced necroinflammatory lesions. On the other hand, beneficial effects of NSAIDs regarding the colonization potential with C. albicans have been reported. Our aim was to investigate whether the association between NSAIDs and C. albicans could potentially induce necroinflammatory lesions in the guinea pigs gastric and enteral mucosa. Three interventional groups of 11 guinea pigs each were investigated after 5 days of receiving indomethacin, C. albicans or the association of both. C. albicans and necroinflammatory lesions were graded based on histological examinations. Statistical analysis used Mann-Whitney nonparametric test. NSAIDs did not significantly decrease C. albicans colonization grades on gastrointestinal mucosa. Administration of indomethacin subsequent to C. albicans determined significantly more severe necroinflammatory lesions compared to group that only received C. albicans. The association of NSAIDs and C. albicans did not cause significantly more severe degenerative or inflammatory lesions compared to the administration of only NSAIDs in this experimental model. Associations between NSAIDs and C. albicans caused significantly more severe necroinflammatory injuries than the lesions produced by C. albicans, without enhancing the mucosal injury or inflammation caused by NSAIDs. PMID:23334509

  12. Antifungal activity, kinetics and molecular mechanism of action of garlic oil against Candida albicans.

    Science.gov (United States)

    Li, Wen-Ru; Shi, Qing-Shan; Dai, Huan-Qin; Liang, Qing; Xie, Xiao-Bao; Huang, Xiao-Mo; Zhao, Guang-Ze; Zhang, Li-Xin

    2016-01-01

    The antifungal activity, kinetics, and molecular mechanism of action of garlic oil against Candida albicans were investigated in this study using multiple methods. Using the poisoned food technique, we determined that the minimum inhibitory concentration of garlic oil was 0.35 μg/mL. Observation by transmission electron microscopy indicated that garlic oil could penetrate the cellular membrane of C. albicans as well as the membranes of organelles such as the mitochondria, resulting in organelle destruction and ultimately cell death. RNA sequencing analysis showed that garlic oil induced differential expression of critical genes including those involved in oxidation-reduction processes, pathogenesis, and cellular response to drugs and starvation. Moreover, the differentially expressed genes were mainly clustered in 19 KEGG pathways, representing vital cellular processes such as oxidative phosphorylation, the spliceosome, the cell cycle, and protein processing in the endoplasmic reticulum. In addition, four upregulated proteins selected after two-dimensional fluorescence difference in gel electrophoresis (2D-DIGE) analysis were identified with high probability by mass spectrometry as putative cytoplasmic adenylate kinase, pyruvate decarboxylase, hexokinase, and heat shock proteins. This is suggestive of a C. albicans stress responses to garlic oil treatment. On the other hand, a large number of proteins were downregulated, leading to significant disruption of the normal metabolism and physical functions of C. albicans. PMID:26948845

  13. Liquid and vapour-phase antifungal activities of selected essential oils against candida albicans: microscopic observations and chemical characterization of cymbopogon citratus

    Directory of Open Access Journals (Sweden)

    Malik Anushree

    2010-11-01

    Full Text Available Abstract Background Use of essential oils for controlling Candida albicans growth has gained significance due to the resistance acquired by pathogens towards a number of widely-used drugs. The aim of this study was to test the antifungal activity of selected essential oils against Candida albicans in liquid and vapour phase and to determine the chemical composition and mechanism of action of most potent essential oil. Methods Minimum Inhibitory concentration (MIC of different essential oils in liquid phase, assayed through agar plate dilution, broth dilution & 96-well micro plate dilution method and vapour phase activity evaluated through disc volatilization method. Reduction of C. albicans cells with vapour exposure was estimated by kill time assay. Morphological alteration in treated/untreated C. albicans cells was observed by the Scanning electron microscopy (SEM/Atomic force microscopy (AFM and chemical analysis of the strongest antifungal agent/essential oil has been done by GC, GC-MS. Results Lemon grass (Cymbopogon citratus essential oil exhibited the strongest antifungal effect followed by mentha (Mentha piperita and eucalyptus (Eucalyptus globulus essential oil. The MIC of lemon grass essential oil in liquid phase (288 mg/l was significantly higher than that in the vapour phase (32.7 mg/l and a 4 h exposure was sufficient to cause 100% loss in viability of C. albicans cells. SEM/AFM of C. albicans cells treated with lemon grass essential oil at MIC level in liquid and vapour phase showed prominent shrinkage and partial degradation, respectively, confirming higher efficacy of vapour phase. GC-MS analysis revealed that lemon grass essential oil was dominated by oxygenated monoterpenes (78.2%; α-citral or geranial (36.2% and β-citral or neral (26.5%, monoterpene hydrocarbons (7.9% and sesquiterpene hydrocarbons (3.8%. Conclusion Lemon grass essential oil is highly effective in vapour phase against C. albicans, leading to deleterious

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

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    Anand Srinivasan

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

  15. Laminin receptors on Candida albicans germ tubes.

    OpenAIRE

    Bouchara, J P; Tronchin, G; Annaix, V; Robert, R; Senet, J M

    1990-01-01

    Recent evidence for the role of laminin in cell adhesion and in the pathogenesis of several bacterial infections has led us to investigate the existence of receptors for this extracellular matrix component in Candida albicans. At first, immunofluorescence demonstrated the presence of laminin-binding sites at the surface of germ tubes. Electron microscopy confirmed this result and permitted precise localization of the binding sites on the outermost fibrillar layer of the germ tube cell wall. B...

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

    Science.gov (United States)

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

    2016-01-01

    Chorioamnionitis is caused by intrauterine infection with microorganisms including Candida albicans (C.albicans). Chorioamnionitis is associated with postnatal intestinal pathologies including necrotizing enterocolitis. The underlying mechanisms by which intra-amniotic C.albicans infection adversely affects the fetal gut remain unknown. Therefore, we assessed whether intra-amniotic C.albicans infection would cause intestinal inflammation and mucosal injury in an ovine model. Additionally, we tested whether treatment with the fungistatic fluconazole ameliorated the adverse intestinal outcome of intra-amniotic C.albicans infection. Pregnant sheep received intra-amniotic injections with 10(7) colony-forming units C.albicans or saline at 3 or 5 days before preterm delivery at 122 days of gestation. Fetuses were given intra-amniotic and intra-peritoneal fluconazole treatments 2 days after intra-amniotic administration of C.albicans. Intra-amniotic C.albicans caused intestinal colonization and invasive growth within the fetal gut with mucosal injury and intestinal inflammation, characterized by increased CD3(+) lymphocytes, MPO(+) cells and elevated TNF-α and IL-17 mRNA levels. Fluconazole treatment in utero decreased intestinal C.albicans colonization, mucosal injury but failed to attenuate intestinal inflammation. Intra-amniotic C.albicans caused intestinal infection, injury and inflammation. Fluconazole treatment decreased mucosal injury but failed to ameliorate C.albicans-mediated mucosal inflammation emphasizing the need to optimize the applied antifungal therapeutic strategy. PMID:27411776

  17. Chemical screening identifies filastatin, a small molecule inhibitor of Candida albicans adhesion, morphogenesis, and pathogenesis

    OpenAIRE

    Fazly, Ahmed; Jain, Charu; Dehner, Amie C.; Issi, Luca; Lilly, Elizabeth A.; Ali, Akbar; Cao, Hong; Fidel, Paul L.; P. Rao, Reeta; Kaufman, Paul D.

    2013-01-01

    Infection by pathogenic fungi, such as Candida albicans, begins with adhesion to host cells or implanted medical devices followed by biofilm formation. By high-throughput phenotypic screening of small molecules, we identified compounds that inhibit adhesion of C. albicans to polystyrene. Our lead candidate compound also inhibits binding of C. albicans to cultured human epithelial cells, the yeast-to-hyphal morphological transition, induction of the hyphal-specific HWP1 promoter, biofilm forma...

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

    OpenAIRE

    Sarah Kartimah Djajusman; Udijanto Tedjosasongko; Irmawati Irmawati

    2014-01-01

    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 sucros...

  19. Three distinct secreted aspartyl proteinases in Candida albicans.

    OpenAIRE

    White, T C; Miyasaki, S H; Agabian, N

    1993-01-01

    The secreted aspartyl proteinases of Candida albicans (products of the SAP genes) are thought to contribute to virulence through their effects on Candida adherence, invasion, and pathogenicity. From a single strain of C. albicans (WO-1) which expresses a phenotypic switching system, three secreted aspartyl proteinases have been identified as determined by molecular weight and N-terminal sequence. Each of the three identified proteins represents the mature form of one of three distinct protein...

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

    OpenAIRE

    Bokor-Bratić Marija B.

    2008-01-01

    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 conside...

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

    Directory of Open Access Journals (Sweden)

    Deforce Dieter

    2006-08-01

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

  2. Candida albicans Quorum Sensing Molecules Stimulate Mouse Macrophage Migration.

    Science.gov (United States)

    Hargarten, Jessica C; Moore, Tyler C; Petro, Thomas M; Nickerson, Kenneth W; Atkin, Audrey L

    2015-10-01

    The polymorphic commensal fungus Candida albicans causes life-threatening disease via bloodstream and intra-abdominal infections in immunocompromised and transplant patients. Although host immune evasion is a common strategy used by successful human fungal pathogens, C. albicans provokes recognition by host immune cells less capable of destroying it. To accomplish this, C. albicans white cells secrete a low-molecular-weight chemoattractive stimulant(s) of macrophages, a phagocyte that they are able to survive within and eventually escape from. C. albicans opaque cells do not secrete this chemoattractive stimulant(s). We report here a physiological mechanism that contributes to the differences in the interaction of C. albicans white and opaque cells with macrophages. E,E-Farnesol, which is secreted by white cells only, is a potent stimulator of macrophage chemokinesis, whose activity is enhanced by yeast cell wall components and aromatic alcohols. E,E-farnesol results in up to an 8.5-fold increase in macrophage migration in vitro and promotes a 3-fold increase in the peritoneal infiltration of macrophages in vivo. Therefore, modulation of farnesol secretion to stimulate host immune recognition by macrophages may help explain why this commensal is such a successful pathogen. PMID:26195556

  3. Development of DNA probes for Candida albicans

    International Nuclear Information System (INIS)

    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 32P- 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

  4. 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.

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

    OpenAIRE

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

    2014-01-01

    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. Resul...

  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. Candida albicans--adriamycin interactions: ultrastructural and spectrofluorometric study of whole yeasts and spheroplasts.

    Science.gov (United States)

    Bobichon, H; Bussy, V; Angiboust, J F; Manfait, M; Bouchet, P; Jardillier, J C

    1990-01-01

    The occurrence of candidiasis in cancer patients who undergo chemotherapy requires the interrelation of Candida albicans and the antimitotic drug Adriamycin (ADM) which is well known as an intercalating agent. The whole yeasts were not affected by 2 h of contact with the drug at 10(-4) M neither for their growth curve nor for their ultrastructure, despite the presence of free ADM on their surface. Spheroplasts displayed a delay in their growth and exhibited altered nucleoli with segregation of their granular and fibrillar components. The modified emission spectrum of ADM, determined by spectrofluorometry, corresponded neither to the free ADM nor to the DNA-bound drug, but it could be related to a metabolite of the drug. The cell wall appeared to be one of the main sites for ADM resistance of Candida albicans in vitro. PMID:2085691

  8. Coaggregation of Streptococcus sanguis and other streptococci with Candida albicans.

    Science.gov (United States)

    Jenkinson, H F; Lala, H C; Shepherd, M G

    1990-01-01

    Thirteen strains of viridans group streptococci and two strains of other streptococci were tested for coaggregation with Candida albicans. Streptococcus sanguis strains generally exhibited low levels of adherence to 28 degrees C-grown exponential-phase yeast cells, but starvation of yeast cells for glucose at 37 degrees C (or at 28 degrees C) increased their coaggregating activity with these streptococci by at least tenfold. This was a property common to four C. albicans strains tested, two of which were able to form mycelia (6406 and MEN) and two of which were not (MM2002 and CA2). The expression of the coaggregation adhesin during yeast cell starvation was inhibited by addition of trichodermin or amphotericin B. The strains of S. sanguis, Streptococcus gordonii, and Streptococcus oralis tested for coaggregating activity encompassed a diverse range of physiological and morphological types, yet all exhibited saturable coaggregation with starved C. albicans cells. There was no correlation of cell surface hydrophobicity, of either yeast or streptococcal cells, with their abilities to coaggregate. Strains of Streptococcus anginosus also coaggregated with starved yeast cells; Streptococcus salivarius and Streptococcus pyogenes coaggregated to a lesser degree with C. albicans, and the coaggregation with S. pyogenes was not promoted by yeast cell starvation; Streptococcus mutans and Enterococcus faecalis did not coaggregate with yeast. The coaggregation reactions of S. sanguis and S. gordonii with C. albicans were inhibited by EDTA and by heat or protease treatment of the yeast cells and were not reversible by the addition of lactose or other simple sugars. These observations extend the range of intergeneric coaggregations that are known to occur between oral microbes and suggest that coaggregations of C. albicans with viridans group streptococci may be important for colonization of oral surfaces by the yeast. PMID:2182544

  9. Inhibition of Candida albicans CC biofilms formation in polystyrene plate surfaces by biosurfactant produced by Trichosporon montevideense CLOA72.

    Science.gov (United States)

    Monteiro, Andrea S; Miranda, Tatiana T; Lula, Ivana; Denadai, Ângelo M L; Sinisterra, Rubén D; Santoro, Marcelo M; Santos, Vera L

    2011-06-01

    This study evaluated the effects of glycolipid-type biosurfactant produced by Trichosporon montevideense CLOA72 in the formation of biofilms in polystyrene plate surfaces by Candida albicans CC isolated from the apical tooth canal. Biofilm formation was reduced up to 87.4% with use of biosurfactant at 16 mg/ml concentration. It has been suggested that the interaction with the cell or polystyrene plate surface could ultimately be responsible for these actions. Therefore, the interaction of C. albicans CC cells with the biosurfactant, as well as the corresponding thermodynamic parameters, have been determined by isothermal titration calorimetry and zeta potential measurements. This process is endothermic (((int)H°=+1284±5 cal/mg OD(600)) occurring with a high increase of entropy (T((int)S°=+10635 cal/mg OD(600)). The caloric energy rate data released during the titulation indicates saturation of the cell-biosurfactant at 1.28 mg/ml OD(600). Also, the zeta potential of the cell surface was monitored as a function of the biosurfactant concentration added to cell suspension showing partial neutralization of net surface charge, since the value of zeta potential ranged from -16 mV to -6 mV during the titration. The changes of cell surface characteristics can contribute to the inhibition of initial adherence of cells of C. albicans in surface. The CMC of the purified biosurfactant produced from T. montevideense CLOA72 is 2.2 mg/ml, as determined both by ITC dilution experiments and by surface tension measurements. This biomolecule did not presented any cytotoxic effect in HEK 293A cell line at concentrations of 0.25-1 mg/ml. This study suggests a possible application of the referred biosurfactant in inhibiting the formation of biofilms on plastic surfaces by C. albicans. PMID:21376544

  10. Antimicrobial Photodynamic Inactivation Inhibits Candida albicans Virulence Factors and Reduces In Vivo Pathogenicity

    Science.gov (United States)

    Sabino, Caetano Padial; Fuchs, Beth Burgwyn; Tegos, George P.; Mylonakis, Eleftherios; Hamblin, Michael R.; Ribeiro, Martha Simões

    2013-01-01

    The objective of this study was to evaluate whether Candida albicans exhibits altered pathogenicity characteristics following sublethal antimicrobial photodynamic inactivation (APDI) and if such alterations are maintained in the daughter cells. C. albicans was exposed to sublethal APDI by using methylene blue (MB) as a photosensitizer (0.05 mM) combined with a GaAlAs diode laser (λ 660 nm, 75 mW/cm2, 9 to 27 J/cm2). In vitro, we evaluated APDI effects on C. albicans growth, germ tube formation, sensitivity to oxidative and osmotic stress, cell wall integrity, and fluconazole susceptibility. In vivo, we evaluated C. albicans pathogenicity with a mouse model of systemic infection. Animal survival was evaluated daily. Sublethal MB-mediated APDI reduced the growth rate and the ability of C. albicans to form germ tubes compared to untreated cells (P < 0.05). Survival of mice systemically infected with C. albicans pretreated with APDI was significantly increased compared to mice infected with untreated yeast (P < 0.05). APDI increased C. albicans sensitivity to sodium dodecyl sulfate, caffeine, and hydrogen peroxide. The MIC for fluconazole for C. albicans was also reduced following sublethal MB-mediated APDI. However, none of those pathogenic parameters was altered in daughter cells of C. albicans submitted to APDI. These data suggest that APDI may inhibit virulence factors and reduce in vivo pathogenicity of C. albicans. The absence of alterations in daughter cells indicates that APDI effects are transitory. The MIC reduction for fluconazole following APDI suggests that this antifungal could be combined with APDI to treat C. albicans infections. PMID:23129051

  11. 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 albicans biofilm development and modulate virulence factors and structural organization of cell wall component β-glucan. PMID:26899861

  12. Oropharyngeal Candidiasis in HIV Infection: Analysis of Impaired Mucosal Immune Response to Candida albicans in Mice Expressing the HIV-1 Transgene

    Directory of Open Access Journals (Sweden)

    Louis de Repentigny

    2015-06-01

    Full Text Available IL-17-producing Th17 cells are of critical importance in host defense against oropharyngeal candidiasis (OPC. Speculation about defective Th17 responses to oral C. albicans infection in the context of HIV infection prompted an investigation of innate and adaptive immune responses to Candida albicans in transgenic mice expressing the genome of HIV-1 in immune cells and displaying an AIDS-like disease. Defective IL-17 and IL-22-dependent mucosal responses to C. albicans were found to determine susceptibility to OPC in these transgenic mice. Innate phagocytes were quantitatively and functionally intact, and individually dispensable for control of OPC and to prevent systemic dissemination of Candida to deep organs. CD8+ T-cells recruited to the oral mucosa of the transgenic mice limited the proliferation of C. albicans in these conditions of CD4+ T-cell deficiency. Therefore, the immunopathogenesis of OPC in the context of HIV infection involves defective T-cell-mediated immunity, failure of crosstalk with innate mucosal immune effector mechanisms, and compensatory cell responses, which limit Candida infection to the oral mucosa and prevent systemic dissemination.

  13. Oropharyngeal Candidiasis in HIV Infection: Analysis of Impaired Mucosal Immune Response to Candida albicans in Mice Expressing the HIV-1 Transgene.

    Science.gov (United States)

    de Repentigny, Louis; Goupil, Mathieu; Jolicoeur, Paul

    2015-01-01

    IL-17-producing Th17 cells are of critical importance in host defense against oropharyngeal candidiasis (OPC). Speculation about defective Th17 responses to oral C. albicans infection in the context of HIV infection prompted an investigation of innate and adaptive immune responses to Candida albicans in transgenic mice expressing the genome of HIV-1 in immune cells and displaying an AIDS-like disease. Defective IL-17 and IL-22-dependent mucosal responses to C. albicans were found to determine susceptibility to OPC in these transgenic mice. Innate phagocytes were quantitatively and functionally intact, and individually dispensable for control of OPC and to prevent systemic dissemination of Candida to deep organs. CD8+ T-cells recruited to the oral mucosa of the transgenic mice limited the proliferation of C. albicans in these conditions of CD4+ T-cell deficiency. Therefore, the immunopathogenesis of OPC in the context of HIV infection involves defective T-cell-mediated immunity, failure of crosstalk with innate mucosal immune effector mechanisms, and compensatory cell responses, which limit Candida infection to the oral mucosa and prevent systemic dissemination. PMID:26110288

  14. 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.

  15. The Cek1‑mediated MAP kinase pathway regulates exposure of α‑1,2 and β‑1,2‑mannosides in the cell wall of Candida albicans modulating immune recognition.

    Science.gov (United States)

    Román, E; Correia, I; Salazin, A; Fradin, C; Jouault, T; Poulain, D; Liu, F-T; Pla, J

    2016-07-01

    The Cek1 MAP kinase (MAPK) mediates vegetative growth and cell wall biogenesis in the fungal pathogen Candida albicans. Alterations in the fungal cell wall caused by a defective Cek1‑mediated signaling pathway leads to increased β‑1,3‑glucan exposure influencing dectin‑1 fungal recognition by immune cells. We show here that cek1 cells also display an increased exposure of α‑1,2 and β‑1,2‑mannosides (α‑M and β‑M), a phenotype shared by strains defective in the activating MAPKK Hst7, suggesting a general defect in cell wall assembly. cek1 cells display walls with loosely bound material as revealed by transmission electron microscopy and are sensitive to tunicamycin, an inhibitor of N‑glycosylation. Transcriptomal analysis of tunicamycin treated cells revealed a differential pattern between cek1 and wild type cells which involved mainly cell wall and stress related genes. Mapping α‑M and β‑M epitopes in the mannoproteins of different cell wall fractions (CWMP) revealed an important shift in the molecular weight of the mannan derived from mutants defective in this MAPK pathway. We have also assessed the role of galectin‑3, a member of a β‑galactoside‑binding protein family shown to bind to and kill C. albicans through β‑M recognition, in the infection caused by cek1 mutants. Increased binding of cek1 to murine macrophages was shown to be partially blocked by lactose. Galectin-3(-/-) mice showed increased resistance to fungal infection, although galectin-3 did not account for the reduced virulence of cek1 mutants in a mouse model of systemic infection. All these data support a role for the Cek1‑mediated pathway in fungal cell wall maintenance, virulence and antifungal discovery. PMID:27191378

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

    Science.gov (United States)

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

    2016-09-20

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

  17. Skin Immunity to Candida albicans.

    Science.gov (United States)

    Kashem, Sakeen W; Kaplan, Daniel H

    2016-07-01

    Candida albicans is a dimorphic commensal fungus that colonizes healthy human skin, mucosa, and the reproductive tract. C. albicans is also a predominantly opportunistic fungal pathogen, leading to disease manifestations such as disseminated candidiasis and chronic mucocutaneous candidiasis (CMC). The differing host susceptibilities for the sites of C. albicans infection have revealed tissue compartmentalization with tailoring of immune responses based on the site of infection. Furthermore, extensive studies of host genetics in rare cases of CMC have identified conserved genetic pathways involved in immune recognition and the response to the extracellular pathogen. We focus here on human and mouse skin as a site of C. albicans infection, and we review established and newly discovered insights into the cellular pathways that promote cutaneous antifungal immunity. PMID:27178391

  18. Mucosal biofilms of Candida albicans

    OpenAIRE

    Ganguly, Shantanu; Mitchell, Aaron P.

    2011-01-01

    Biofilms are microbial communities that form on surfaces and are embedded in an extracellular matrix. C. albicans forms pathogenic mucosal biofilms that are evoked by changes in host immunity or mucosal ecology. Mucosal surfaces are inhabited by many microbial species; hence these biofilms are polymicrobial. Several recent studies have applied paradigms of biofilm analysis to study mucosal C. albicans infections. These studies reveal that the Bcr1 transcription factor is a master regulator of...

  19. Proinflammatory chemokines during Candida albicans keratitis.

    Science.gov (United States)

    Yuan, Xiaoyong; Hua, Xia; Wilhelmus, Kirk R

    2010-03-01

    Chemotactic cytokines mediate the recruitment of leukocytes into infected tissues. This study investigated the profile of chemokines during experimental Candida albicans keratitis and determined the effects of chemokine inhibition on leukocyte infiltration and fungal growth during murine keratomycosis. Scarified corneas of BALB/c mice were topically inoculated with C. albicans and monitored daily over one week for fungal keratitis. After a gene microarray for murine chemokines compared infected corneas to controls, real-time reverse transcription polymerase chain reaction (RT-PCR) and immunostaining assessed chemokine expression in infected and mock-inoculated corneas. An anti-chemokine antibody was then administered subconjunctivally and evaluated for effects on clinical severity, corneal inflammation, fungal recovery, and cytokine expression. Of 33 chemokine genes examined by microarray, 6 CC chemokines and 6 CXC chemokines were significantly (Pamount of recoverable fungi was not significantly (P=0.4) affected. Anti-CCL3 treatment significantly (P=0.01) reduced the expression of tumor necrosis factor and interleukin-1beta in infected corneas. These results indicate that chemokines, especially the CC chemokine CCL3, play important roles in the acute inflammatory response to C. albicans corneal infection. PMID:20005222

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  1. The effect of cryptolepine on the morphology and survival of Escherichia coli, Candida albicans and Saccharomyces cerevisiae.

    Science.gov (United States)

    Sawer, I K; Berry, M I; Brown, M W; Ford, J L

    1995-09-01

    The antimicrobial activity of the indoloquinoline alkaloid, cryptolepine, isolated from Cryptolepis sanguinolenta (Fam. Periplocaceae) was determined against selected micro-organisms. The minimum inhibitory concentration (MIC) ranges obtained, expressed as microgram ml-1, were: 5-10 for Saccharomyces cerevisiae NCPF 3139; 10-20 for S. cerevisiae NCPF 3178; 20-40 for Escherichia coli NCTC 10418; 40-80 for E. coli NCTC 11560, Candida albicans ATCC 10231 and C. tropicalis NCPF; and 80-160 for C. albicans NCPF 3242 and NCPF 3262. Biocidal effects were noted at concentrations 2-4 times those of the MIC of the alkaloid following challenge with 10(6) cfu ml-1 of micro-organisms. Time-kill studies showed a reduction in viable count from 10(6) to < 10 cfu ml-1 in 4 h in C. albicans ATCC 10231 exposed to 320 micrograms ml-1 of the agent; 3 log cycle reductions were recorded for the 6 h counts of E. coli NCTC 10418 and S. cerevisiae NCPF 3139 exposed to 40 micrograms ml-1 and 160 micrograms ml-1 of the alkaloid respectively. These results were consistent with findings using scanning electron microscopy. Exposure of cells to biocidal concentrations of cryptolepine produced filamentation prior to lysis in E. coli NCTC 10418 and extreme disturbance of surface structure, including partial and total collapse, followed by lysis in C. albicans ATCC 10231 and S. cerevisiae NCPF 3139. PMID:7592125

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-03-05

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2011-01-01

    We have developed a high-density microarray platform consisting of nano-biofilms of Candida albicans. A robotic microarrayer was used to print yeast cells of C. albicans encapsulated in a collagen matrix at a volume as low as 50 nL onto surface-modified microscope slides. Upon incubation, the cells grow into fully formed “nano-biofilms”. The morphological and architectural complexity of these biofilms were evaluated by scanning electron and confocal scanning laser microscopy. The extent of bi...

  5. Oxidative Stress Responses in the Human Fungal Pathogen, Candida albicans

    Directory of Open Access Journals (Sweden)

    Alessandra da Silva Dantas

    2015-02-01

    Full Text Available Candida albicans is a major fungal pathogen of humans, causing approximately 400,000 life-threatening systemic infections world-wide each year in severely immunocompromised patients. An important fungicidal mechanism employed by innate immune cells involves the generation of toxic reactive oxygen species (ROS, such as superoxide and hydrogen peroxide. Consequently, there is much interest in the strategies employed by C. albicans to evade the oxidative killing by macrophages and neutrophils. Our understanding of how C. albicans senses and responds to ROS has significantly increased in recent years. Key findings include the observations that hydrogen peroxide triggers the filamentation of this polymorphic fungus and that a superoxide dismutase enzyme with a novel mode of action is expressed at the cell surface of C. albicans. Furthermore, recent studies have indicated that combinations of the chemical stresses generated by phagocytes can actively prevent C. albicans oxidative stress responses through a mechanism termed the stress pathway interference. In this review, we present an up-date of our current understanding of the role and regulation of oxidative stress responses in this important human fungal pathogen.

  6. Enzymatic Dysfunction of Mitochondrial Complex I of the Candida albicans goa1 Mutant Is Associated with Increased Reactive Oxidants and Cell Death ▿

    OpenAIRE

    Li, Dongmei; Chen, Hui; Florentino, Abigail; Alex, Deepu; Sikorski, Patricia; Fonzi, William A.; Calderone, Richard

    2011-01-01

    We have previously shown that deletion of GOA1 (growth and oxidant adaptation) of Candida albicans results in a loss of mitochondrial membrane potential, ATP synthesis, increased sensitivity to oxidants and killing by human neutrophils, and avirulence in a systemic model of candidiasis. We established that translocation of Goa1p to mitochondria occurred during peroxide stress. In this report, we show that the goa1Δ (GOA31), compared to the wild type (WT) and a gene-reconstituted (GOA32) strai...

  7. Initiation of phospholipomannan β-1,2 mannosylation involves Bmts with redundant activity, influences its cell wall location and regulates β-glucans homeostasis but is dispensable for Candida albicans systemic infection.

    Science.gov (United States)

    Courjol, F; Mille, C; Hall, R A; Masset, A; Aijjou, R; Gow, N A R; Poulain, D; Jouault, T; Fradin, C

    2016-01-01

    Pathogenic and non-pathogenic fungi synthesize glycosphingolipids, which have a crucial role in growth and viability. Glycosphingolipids also contribute to fungal-associated pathogenesis. The opportunistic yeast pathogen Candida albicans synthesizes phospholipomannan (PLM), which is a glycosphingolipid of the mannosylinositol phosphorylceramide family. Through its lipid and glycan moieties, PLM contributes to the initial recognition of the yeast, causing immune system disorder and persistent fungal disease through activation of host signaling pathways. The lipid moiety of PLM activates the deregulation signaling pathway involved in yeast phagocytosis whereas its glycan moiety, composed of β-1,2 mannosides (β-Mans), participates to inflammatory processes through a mechanism involving Galectin-3. Biosynthesis of PLM β-Mans involves two β-1,2 mannosyltransferases (Bmts) that initiate (Bmt5) and elongate (Bmt6) the glycan chains. After generation of double bmtsΔ mutants, we show that Bmt5 has redundant activity with Bmt2, which can replace Bmt5 in bmt5Δ mutant. We also report that PLM is located in the inner layer of the yeast cell wall. PLM seems to be not essential for systemic infection of the yeast. However, defect of PLM β-mannosylation increases resistance of C. albicans to inhibitors of β-glucans and chitin synthesis, highlighting a role of PLM in cell wall homeostasis. PMID:26427558

  8. Doxorubicin induces drug efflux pumps in Candida albicans.

    Science.gov (United States)

    Kofla, Grzegorz; Turner, Vincent; Schulz, Bettina; Storch, Ulrike; Froelich, Daniela; Rognon, Bénédicte; Coste, Alix T; Sanglard, Dominique; Ruhnke, Markus

    2011-02-01

    Candida albicans is one of the most important opportunistic fungal pathogens. It can cause serious fungal diseases in immunocompromised patients, including those with cancer. Treatment failures due to the emergence of drug-resistant C. albicans strains have become a serious clinical problem. Resistance incidents were often mediated by fungal efflux pumps which are closely related to the human ABC transporter P-glycoprotein (P-gp). P-gp is often overexpressed in cancer cells and confers resistance to many cytotoxic drugs. We examined whether cytotoxic drugs commonly used for cancer treatment (doxorubicin and cyclophosphamide) could alter the expression of genes responsible for the development of fluconazole resistance in Candida cells in the way they can influence homologous genes in cancer cell lines. ABC transporters (CDR1 and CDR2) and other resistance genes (MDR1 and ERG11) were tested by real-time PCR for their expression in C. albicans cells at the mRNA level after induction by antineoplastic drugs. The results were confirmed by a lacZ gene reporter system and verified at the protein level using GFP and immunoblotting. We showed that doxorubicin is a potent inducer of CDR1/CDR2 expression in C. albicans at both the mRNA and protein level and thus causes an increase in fluconazole MIC values. However, cyclophosphamide, which is not a substrate of human P-gp, did not induce ABC transporter expression in C. albicans. Neither doxorubicin nor cyclophosphamide could influence the expression of the other resistance genes (MDR1 and ERG11). The induction of CDR1/CDR2 by doxorubicin in C. albicans and the resulting alteration of antifungal susceptibility might be of clinical relevance for the antifungal treatment of Candida infections occurring after anticancer chemotherapy with doxorubicin. PMID:20818920

  9. 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.

  10. 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. PMID:26934196

  11. Expression, crystallization and preliminary X-ray data analysis of NT-Als9-2, a fungal adhesin from Candida albicans

    International Nuclear Information System (INIS)

    Details of the expression and crystallization of the N-terminal fragment of Als9-2, an adhesin from the human commensal/pathogenic fungus C. albicans, are reported. Preliminary analysis of the collected X-ray data is also discussed. Candida albicans is a common human fungal commensal that can also cause a range of infections from skin/mucosal ‘thrush’ to severe systemic candidiasis. Adherence to host cells is one of the key determinants of Candida pathogenesis. The Als family of surface proteins has been implicated in adhesion of C. albicans, yet limited information has been published on the structure and mechanism of these fungal adhesins. The N-terminal region of these proteins has been shown to possess adhesive properties, making it a possible target for new therapeutic strategies. Recombinant NT-Als9-2 from C. albicans (residues 18–329) was overexpressed in Escherichia coli, purified and crystallized. Diffraction data were collected to 2.0 Å resolution. The crystals belonged to space group P212121, with unit-cell parameters a = 34.73, b = 68.71, c = 120.03 Å, α = β = γ = 90° and one molecule in the asymmetric unit. Platinum-derivatized crystals belonged to the same space group, with similar unit-cell parameters, although they were not completely isomorphous

  12. The exocyst in Candida albicans polarized secretion and filamentation.

    Science.gov (United States)

    Chavez-Dozal, Alba A; Bernardo, Stella M; Lee, Samuel A

    2016-05-01

    The exocyst is an octameric complex that orchestrates the docking and tethering of vesicles to the plasma membrane during exocytosis and is fundamental for key biological processes including growth and establishment of cell polarity. Although components of the exocyst are well conserved among fungi, the specific functions of each component of the exocyst complex unique to Candida albicans biology and pathogenesis are not fully understood. This commentary describes recent findings regarding the role of exocyst subunits Sec6 and Sec15 in C. albicans filamentation and virulence. PMID:26762634

  13. Adhesion ability of Candida albicans with different biological states for o-ral epithelial cells and its ALS mRNA expression%不同生物状态白色念珠菌对口腔上皮细胞的黏附能力及ALS mRNA表达

    Institute of Scientific and Technical Information of China (English)

    张辉; 叶美花; 俞诚波; 张蓓蓓; 蔡敏秋; 许红苗

    2015-01-01

    目的:观察不同生物状态白色念珠菌对口腔上皮细胞的黏附能力及ALS mRNA表达,以期揭示口腔白色念球菌感染机制。方法将白色念珠菌3683、SC5314、3630与来源于50名健康志愿者的口腔上皮细胞混合培养,采用革兰阳性染色观察白色念珠菌的黏附能力,采用荧光定量RT-PCR法检测白色念珠菌3683、SC5314、3630中ALS2及ALS3 mRNA表达情况。采用SPSS 15.0统计学软件进行数据分析。结果黏附实验结果显示,3株白色念珠菌均可黏附于口腔上皮细胞,且菌株3683黏附数量明显多于菌株SC5314和菌株3630,统计学比较显示,差异有统计学意义(P0.05)。荧光定量RT-PCR结果显示,白色念珠菌3683、SC5314、3630中均能检测到ALS2及ALS3 mRNA表达,其中,菌株3683 ALS2及ALS3 mRNA表达水平均高于菌株SC5314和菌株3630,统计学比较显示,差异有统计学意义(P0.05)。结论不同生物状态白色念珠菌的口腔上皮细胞黏附能力不同,菌株黏附能力的强弱可能与其ALS2及ALS3基因情况表达相关。%Objective To observe the adhesion ability of Candida albicans with different biological states for oral ep-ithelial cells and its ALS mRNA expression, in order to reveal the mechanism of oral Candida albicans infection. Methods Candida albicans 3683, SC5314, 3630 and oral epithelial cells from 50 cases of healthy volunteers were mixed cultivation. Gram positive staining was used to observe the adhesion ability of Candida albicans. Candida albi-cans 3683, SC5314, 3630 ALS2 and ALS3 mRNA expressions were detected by fluorescent quantitation RT-PCR method. SPSS 15.0 statistical software was used for data analysis. Results Adhesion experiment results showed that Candida albicans 3683, SC5314, 3630 could stick to oral epithelial cells. Adhesion level of Candida albicans 3683 was higher than that of Candida albicans SC5314 and 3630, the differences were statistically significant (P0.05). Fluores-cent quantitation

  14. Streptococcus gordonii glucosyltransferase promotes biofilm interactions with Candida albicans

    Directory of Open Access Journals (Sweden)

    Austin Ricker

    2014-01-01

    Full Text Available Background: Candida albicans co-aggregates with Streptococcus gordonii to form biofilms and their interactions in mucosal biofilms may lead to pathogenic synergy. Although the functions of glucosyltransferases (Gtf of Mutans streptococci have been well characterized, the biological roles of these enzymes in commensal oral streptococci, such as S. gordonii, in oral biofilm communities are less clear. Objective: The objective of this work was to explore the role of GtfG, the single Gtf enzyme of S. gordonii, in biofilm interactions with C. albicans. Design: Biofilms were grown under salivary flow in flow cells in vitro, or under static conditions in 96 well plates. A panel of isogenic S. gordonii CH1 gtfG mutants and complemented strains were co-inoculated with C. albicans strain SC5314 to form mixed biofilms. Biofilm accretion and binding interactions between the two organisms were tested. Biofilms were quantified using confocal microscopy or the crystal violet assay. Results: The presence of GtfG enhanced dual biofilm accretion, and sucrose supplementation further augmented dual biofilm formation, pointing to a role of newly synthesized glucans. GtfG also promoted binding to C. albicans preformed biofilms. Soluble α-1,6-glucans played a role in these interactions since: 1 a strain producing only soluble glucans (CH107 formed robust dual biofilms under conditions of salivary flow; and 2 the dual biofilm was susceptible to enzymatic breakdown by dextranase which specifically degrades soluble α-1,6-glucans. Conclusion: Our work identified a novel molecular mechanism for C. albicans and S. gordonii biofilm interactions, mediated by GtfG. This protein promotes early biofilm binding of S. gordonii to C. albicans which leads to increased accretion of streptococcal cells in mixed biofilms. We also showed that soluble glucans, with α-1,6-linkages, promoted inter-generic adhesive interactions.

  15. Effect of Xylitol with Various Concentration and Duration on the Growth of Candida albicans (In Vitro study

    Directory of Open Access Journals (Sweden)

    Lakshmi A. Leepel

    2012-10-01

    Full Text Available The growth of C. albicans is influenced by glucose intake. Xylitol is commonly used as sugar substitute. Reported effective concentrations of xylitol in reducing C. albicans growth in vitro were varied, 1%, 5%, and 10%. Objectives: Investigate the effect of different concentration and duration of xylitol exposure in inhibiting C. albicans growth in vitro. Method: Identification of C. albicans from oral swab of a male candidiasis patient was conducted using CHROMagar, confirmed by germ tube test. C. albicans suspension (108 cells/μl were inoculated in SDB contained 1%, 5%, 10% xylitol, and without xylitol (as control, for 3 and 7 days, then incubated in 37oC on SDA and counted for their CFU after 48 hours. The C. albicans ATCC 10231 strain was used as a comparison. Results: After 3 days, increased concentration of xylitol (1%, 5%, 10% lead to decrease growth of C. albicans, both the ATCC 10231 (125%; 51%; 14% respectively and the clinical isolate (103%; 81%; 42%, p = 0.044. Significant lower growth of C. albicans compared to control were only seen in those exposed to 10% xylitol (p = 0.024. After 7 days, exposure of 1%, 5%, 10% xylitol did not significantly affect the growth of C. albicans (p = 0.396. Conclusion: The growth of C. albicans could be inhibited by 10% xylitol for 3 days.DOI: 10.14693/jdi.v16i1.12

  16. 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.

  17. Mutual co-regulation between GPI-N-acetylglucosaminyltransferase and ergosterol biosynthesis in Candida albicans.

    Science.gov (United States)

    Victoria, Guiliana Soraya; Yadav, Bhawna; Hauhnar, Lalremruata; Jain, Priyanka; Bhatnagar, Shilpi; Komath, Sneha Sudha

    2012-05-01

    A novel co-regulation exists between the first step of GPI (glycosylphosphatidylinositol) anchor biosynthesis and the rate-determining step of ergosterol biosynthesis in Candida albicans. Depleting CaGpi19p, an accessory subunit of the enzyme complex that initiates GPI biosynthesis, down-regulates ERG11, altering ergosterol levels and drug response. This effect is specific to CaGpi19p depletion and is not due to cell wall defects or GPI deficiency. Additionally, down-regulation of ERG11 down-regulates CaGPI19 and GPI biosynthesis. PMID:22390164

  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. Growth profile and SEM analyses of Candida albicans and Escherichia coli with Hymenocallis littoralis (Jacq.) Salisb leaf extract.

    Science.gov (United States)

    Rosli, N; Sumathy, V; Vikneswaran, M; Sreeramanan, S

    2014-12-01

    Hymenocallis littoralis (Jacq.) Salisb (Melong kecil) commonly known as 'Spider Lily' is an herbaceous plant from the family Amaryllidaceae. Study was carried out to determine the effect of H. littoralis leaf extract on the growth and morphogenesis of two pathogenic microbes, Candida albicans and Escherichia coli. The leaf extract displayed favourable anticandidal and antibacterial activity with a minimum inhibition concentration (MIC) of 6.25 mg/mL. Time kill study showed both microbes were completely killed after treated with leaf extract at 20 h. Both microbes' cell walls were heavily ruptured based on scanning electron microscopy (SEM) analysis. The significant anticandidal and antibacterial activities showed by H. littoralis leaf extract suggested the potential antimicrobial agent against C. albicans and E. coli. PMID:25776614

  20. Influence of preformed antibody on the pathogenesis of experimental Candida albicans endocarditis.

    OpenAIRE

    Scheld, W M; Calderone, R A; Brodeur, J P; Sande, M A

    1983-01-01

    The influence of preformed antibody on the induction of experimental Candida albicans endocarditis was investigated by both in vitro and in vivo techniques. Preincubation of C. albicans with immune serum (raised in rabbits by intravenous injection of Formalin-killed yeast cells) decreased adhesion to the constituents of nonbacterial thrombotic endocarditis, e.g., fibrin plus platelets, in vitro. Two different methods, with radiolabeled or viable yeast cells, were confirmatory and demonstrated...

  1. 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.

  2. 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

    OpenAIRE

    C. Hanny Wijaya 2); A. Fieki Rachmatillah1); Bachtiar, Boy M.

    2014-01-01

    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 ...

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  5. CX3CL1 expression induced by Candida albicans in oral fibroblasts.

    Science.gov (United States)

    Ohta, Kouji; Nishi, Hiromi; Fukui, Akiko; Shigeishi, Hideo; Takechi, Masaaki; Kamata, Nobuyuki

    2010-11-01

    Oral fibroblasts as well as keratinocytes are thought to influence host inflammatory responses against Candida albicans. However, little is known about chemokine expressions in oral fibroblasts against C. albicans infection. We therefore examined whether C. albicans induced several chemokines including fractalkine/CX3CL1 (CX3CL1), a unique chemokine that has properties of both chemoattractants and adhesion molecules, in fibroblasts and keratinocytes. The addition of C. albicans live cells to human immortalized oral keratinocytes (RT7) resulted in increases in the mRNA levels of multiple chemokines, but not of CX3CL1. In contrast, live and heat-killed C. albicans caused an increase in CX3CL1 mRNA and protein expression in human immortalized oral fibroblasts (GT1). CX3CL1 mRNA expression in GT1 cells was also enhanced by stimulation with a nonalbicans species of Candida. Further, the CX3CL1 chemokine domain showed antifungal activity against C. albicans. CX3CL1 secreted by oral fibroblasts appears to play an important role in the oral immune response to C. albicans infection. PMID:20880200

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

    Directory of Open Access Journals (Sweden)

    Felipe Francisco Tuon

    2006-10-01

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

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

    OpenAIRE

    Felipe Francisco Tuon; Antonio Carlos Nicodemo

    2006-01-01

    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 relatado...

  8. Effects of salivary protein flow and indigenous microorganisms on initial colonization of Candida albicans in an in vivo model

    Directory of Open Access Journals (Sweden)

    Kanaguchi Norihiko

    2012-08-01

    Full Text Available Abstract Background Candida albicans is a dimorphic fungus that is part of the commensal microbial flora of the oral cavity. When the host immune defenses are impaired or when the normal microbial flora is disturbed, C. albicans triggers recurrent infections of the oral mucosa and tongue. Recently, we produced NOD/SCID.e2f1-/- mice that show hyposalivation, decrease of salivary protein flow, lack IgA and IgG in saliva, and have decreased NK cells. Our objective was to characterize C. albicans infection and biofilm formation in mice. Methods NOD/SCID.e2f1-/- mice were used as an animal model for C. albicans infection. C. albicans yeast and hyphal forms solutions were introduced in the oral cavity after disinfection by Chlorhexidine. Results The numbers of C. albicans colonized and decreased in a time-dependent manner in NOD/SCID.e2f1+/+ after inoculation. However, the colonization levels were higher in NOD/SCID.e2f1+/+ than NOD/SCID.e2f1-/- mice. In the mice fed 1% sucrose water before inoculation, C. albicans sample was highly contaminated by indigenous microorganisms in the oral cavity; and was not in the mice fed no sucrose water. The colonization of C. albicans was not influenced by the contamination of indigenous microorganisms. The hyphal form of C. albicans restricted the restoration of indigenous microorganisms. The decreased saliva in NOD/SCID.e2f1-/- did not increase the colonization of C. albicans in comparison to NOD/SCID.e2f1+/+ mice. We suggest that the receptor in saliva to C. albicans may not be sufficiently provided in the oral cavity of NOD/SCID.e2f1-/- mice. Conclusion The saliva protein flow may be very important for C. albicans initial colonization, where the indigenous microorganisms do not affect colonization in the oral cavity.

  9. GAp permeases in Candida albicans

    Czech Academy of Sciences Publication Activity Database

    Kraidlová, Lucie; Sychrová, Hana; Van Dijck, P.

    Fyziologický ústav AV ČR, v. v. i.. Roč. 57, č. 4 (2008), 79P-79P ISSN 0862-8408. [PhD Student Workshop of Institute of Physiology. 02.06.2008-04.06.2008, Seč] R&D Projects: GA MŠk(CZ) LC531 Institutional research plan: CEZ:AV0Z50110509 Keywords : cpr1 * Candida albicans * amino-acid uptake * GAP permease Subject RIV: EE - Microbiology, Virology

  10. Serum repressing efflux pump CDR1 in Candida albicans

    Directory of Open Access Journals (Sweden)

    Fan Jen-Chung

    2006-07-01

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

  11. 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

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

    Science.gov (United States)

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

    2016-08-01

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

  13. Distinct stages during colonization of the mouse gastrointestinal tract by Candida albicans

    Directory of Open Access Journals (Sweden)

    Daniel ePrieto

    2015-08-01

    Full Text Available Candida albicans is a member of the human microbiota, colonizing both the vaginal and gastrointestinal tracts. This yeast is devoid of a life style outside the human body and the mechanisms underlying the adaptation to the commensal status remain to be determined. Using a model of mouse gastrointestinal colonization, we show here that C. albicans stably colonizes the mouse gut in about 3 days starting from a dose as low as 100 cells, reaching steady levels of around 107 cells/g of stools. Using fluorescent labeled strains we have assessed the competition between isogenic populations from different sources in cohoused animals. We show that long term (15 days colonizing cells have increased fitness in the gut niche over those grown in vitro or residing in the gut for 1-3 days. Therefore, two distinct states, proliferation and adaptation, seem to exist in the adaptation of this fungus to the mouse gut, a result with potential significance in the prophylaxis and treatment of Candida infections.

  14. Milestones in Candida albicans Gene Manipulation

    OpenAIRE

    Samaranayake, Dhanushki P.; Hanes, Steven D.

    2011-01-01

    In the United States, candidemia is one of the most common hospital-acquired infections and is estimated to cause 10,000 deaths per year. The species Candida albicans is responsible for the majority of these cases. As C. albicans is capable of developing resistance against the currently available drugs, understanding the molecular basis of drug resistance, finding new cellular targets, and further understanding the overall mechanism of C. albicans pathogenesis are important goals. To study th...

  15. Impact of oxidative and osmotic stresses on Candida albicans biofilm formation.

    Science.gov (United States)

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

    2016-09-01

    Candida albicans possesses an ability to grow under different host-driven stress conditions by developing robust protective mechanisms. In this investigation the focus was on the impact of osmotic (2M NaCl) and oxidative (5 mM H2O2) stress conditions during C. albicans biofilm formation. Oxidative stress enhanced extracellular DNA secretion into the biofilm matrix, increased the chitin level, and reduced virulence factors, namely phospholipase and proteinase activity, while osmotic stress mainly increased extracellular proteinase and decreased phospholipase activity. Fourier transform infrared and nuclear magnetic resonance spectroscopy analysis of mannan isolated from the C. albicans biofilm cell wall revealed a decrease in mannan content and reduced β-linked mannose moieties under stress conditions. The results demonstrate that C. albicans adapts to oxidative and osmotic stress conditions by inducing biofilm formation with a rich exopolymeric matrix, modulating virulence factors as well as the cell wall composition for its survival in different host niches. PMID:27472386

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

    Science.gov (United States)

    Kaomongkolgit, Ruchadaporn; Jamdee, Kusuma

    2015-01-01

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

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

    OpenAIRE

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

    2011-01-01

    Background: Candida albicans may have cariogenic potential but its role in caries etiology has not been established. The aim of this study was to determine candida albicans in supragingival dental plaque and infected dentine of cervical and proximal in early childhood caries (ECC).

  18. 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,

  19. Candida albicans in oral biofilms could prevent caries.

    Science.gov (United States)

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

    2016-07-01

    Streptococcus mutans is a Gram-positive bacterium involved in development to caries, the most common infectious disease of our time. Streptococcus mutans interacts with other microbes, like the fungus Candida albicans and both are commonly isolated from patients with caries. Since the role of C. albicans in caries remains unknown, our aim was to unravel this using an in vitro dual-species cariogenic oral biofilm model. Biofilms were grown for 24-72 h on glass cover slips or hydroxyapatite (HA) disks to mimic the surface of teeth. Medium pH, lactic acid production capacity and calcium release from HA disks were determined. All 24-h biofilms had external pH values below the critical pH of 5.5 where enamel dissolves. In contrast, 72-h dual-species biofilms had significantly higher pH (above the critical pH) and consequently decreased calcium release compared to single-species S. mutans biofilms. Counter intuitively, lactic acid production and growth of S. mutans were increased in 72-h dual-species biofilms. Candida albicans modulates the pH in dual-species biofilms to values above the critical pH where enamel dissolves. Our results suggest that C. albicans is not by definition a cariogenic microorganism; it could prevent caries by actively increasing pH preventing mineral loss. PMID:27129365

  20. Human submandibular-sublingual saliva promotes adhesion of Candida albicans to polymethylmethacrylate.

    OpenAIRE

    Edgerton, M; Scannapieco, F A; Reddy, M. S.; Levine, M J

    1993-01-01

    The purpose of this study was to identify components of saliva that interact with Candida albicans in solution and that may modulate adhesion to dental acrylic (polymethylmethacrylate [PMMA]) surfaces. Saliva-derived pellicles extracted from C. albicans blastoconidia and hyphal-form cells mixed with fresh human submandibular-sublingual saliva (HSMSL) contained predominantly high- and low-molecular-weight mucins (MG1 and MG2, respectively). In contrast, few components from fresh human parotid ...

  1. CO(2) acts as a signalling molecule in populations of the fungal pathogen Candida albicans

    OpenAIRE

    Hall, Rebecca A.; De Sordi, Luisa; MacCallum, Donna M.; Topal, Husnu; Eaton, Rebecca; Bloor, James W.; Robinson, Gary K.; Levin, Lonny R.; Buck, Jochen; Wang, Yue; Gow, Neil A R; Steegborn, Clemens; Mühlschlegel, Fritz A.

    2010-01-01

    When colonising host-niches or non-animated medical devices, individual cells of the fungal pathogen Candida albicans expand into significant biomasses. Here we show that within such biomasses, fungal metabolically generated CO(2) acts as a communication molecule promoting the switch from yeast to filamentous growth essential for C. albicans pathology. We find that CO(2)-mediated intra-colony signalling involves the adenylyl cyclase protein (Cyr1p), a multi-sensor recently found to coordinate...

  2. Prothioconazole and Prothioconazole-Desthio Activities against Candida albicans Sterol 14-α-Demethylase

    OpenAIRE

    Parker, Josie E.; Warrilow, Andrew G. S.; Cools, Hans J; Fraaije, Bart A.; Lucas, John A.; Rigdova, Katarina; Griffiths, William J.; Kelly, Diane E.; Kelly, Steven L.

    2013-01-01

    Prothioconazole is a new triazolinthione fungicide used in agriculture. We have used Candida albicans CYP51 (CaCYP51) to investigate the in vitro activity of prothioconazole and to consider the use of such compounds in the medical arena. Treatment of C. albicans cells with prothioconazole, prothioconazole-desthio, and voriconazole resulted in CYP51 inhibition, as evidenced by the accumulation of 14α-methylated sterol substrates (lanosterol and eburicol) and the depletion of ergosterol. We the...

  3. Passage through the mammalian gut triggers a phenotypic switch that promotes Candida albicans commensalism

    OpenAIRE

    Pande, Kalyan; Chen, Changbin; Noble, Suzanne M.

    2013-01-01

    Among ~5,000,000 fungal species, 1 Candida albicans is exceptional in its lifelong association with humans, either within the gastrointestinal microbiome or as an invasive pathogen. 2 Opportunistic infections are generally ascribed to defective host immunity 3 but may require specific microbial programs. Here, we report that exposure of C. albicans to the mammalian gut triggers a developmental switch, driven by the Wor1 transcription factor, to a commensal cell type. Wor1 expression was previ...

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

    Directory of Open Access Journals (Sweden)

    Muthuirulan Pushpanathan

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

  5. Candida albicans Biofilms Do Not Trigger Reactive Oxygen Species and Evade Neutrophil Killing

    OpenAIRE

    Xie, Zhihong; Thompson, Angela; Sobue, Takanori; Kashleva, Helena; Xu, Hongbin; Vasilakos, John; Dongari-Bagtzoglou, Anna

    2012-01-01

    Neutrophils are found within Candida albicans biofilms in vivo and could play a crucial role in clearing the pathogen from biofilms forming on catheters and mucosal surfaces. Our goal was to compare the antimicrobial activity of neutrophils against developing and mature C. albicans biofilms and identify biofilm-specific properties mediating resistance to immune cells. Antibiofilm activity was measured with the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)2H-tetrazolium-5-carboxanilide assay and a ...

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

    OpenAIRE

    Wibawa, Tri; Praseno,; Aman, Abu Tholib

    2015-01-01

    Candida sp contributes 33.1 % of fungal infections among HIV patients. Among the species of the genus Candida, Candida albicans is the most frequently isolated from HIV patients. This study aimed to analyze putative virulence factors of C. albicans isolated from oral cavities of HIV infected patients and healthy individuals. Twenty isolates from HIV infected patients and fourteen from healthy individuals were analyzed for phenotypic switching, cell growth rate, hyphae formation, hemolytic act...

  7. Improved Gene Ontology Annotation for Biofilm Formation, Filamentous Growth, and Phenotypic Switching in Candida albicans

    OpenAIRE

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

    2013-01-01

    The opportunistic fungal pathogen Candida albicans is a significant medical threat, especially for immunocompromised patients. Experimental research has focused on specific areas of C. albicans biology, with the goal of understanding the multiple factors that contribute to its pathogenic potential. Some of these factors include cell adhesion, invasive or filamentous growth, and the formation of drug-resistant biofilms. The Gene Ontology (GO) (www.geneontology.org) is a standardized vocabulary...

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

    Science.gov (United States)

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

    2016-01-01

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

  9. Isolation and characterization of Candida albicans morphological mutants derepressed for the formation of filamentous hypha-type structures

    International Nuclear Information System (INIS)

    Several Candida albicans morphological mutants were obtained by a procedure based on a combined treatment with nitrous acid plus UV irradiation and a double-enrichment step to increase the proportion of mutants growing as long filamentous structures. Altered cell morphogenesis in these mutants correlated with an altered colonial phenotype. Two of these mutants, C. albicans NEL102 and NEL103, were selected and characterized. Mutant blastoconidia initiated budding but eventually gave rise to filamentous hypha-type formations. These filaments were long and septate, and they branched very regularly at positions near septa. Calcofluor white (which is known to bind chitin-rich areas) stained septa, branching zones, and filament tips very intensely, as observed under the fluorescence microscope. Wild-type hybrids were obtained by fusing protoplasts of strain NEL102 with B14, another morphological mutant previously described as being permanently pseudomycelial, indicating that genetic determinants responsible for the two altered phenotypes are different. The mutants characterized in this work seemed to sequentially express the morphogenic characteristics of C. albicans, from blastoconidia to hyphae, in the absence of any inducer. Further characterization of these strains could be relevant to gain understanding of the genetic control of dimorphism in this species

  10. 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.

  11. An iron homeostasis regulatory circuit with reciprocal roles in Candida albicans commensalism and pathogenesis

    OpenAIRE

    Chen, Changbin; Pande, Kalyan; French, Sarah D.; Tuch, Brian B.; Noble, Suzanne M.

    2011-01-01

    The mammalian gastrointestinal tract and bloodstream are highly disparate biological niches that differ in concentrations of nutrients such as iron. However, some commensal-pathogenic microorganisms, such as the yeast Candida albicans, thrive in both environments. We report the evolution of a transcription circuit in C. albicans that controls iron uptake and determines its fitness in both niches. Our analysis of DNA-binding proteins that regulate iron uptake by this organism suggests the evol...

  12. Antifungal activity, kinetics and molecular mechanism of action of garlic oil against Candida albicans

    OpenAIRE

    Wen-Ru Li; Qing-Shan Shi; Huan-Qin Dai; Qing Liang; Xiao-Bao Xie; Xiao-Mo Huang; Guang-Ze Zhao; Li-Xin Zhang

    2016-01-01

    The antifungal activity, kinetics, and molecular mechanism of action of garlic oil against Candida albicans were investigated in this study using multiple methods. Using the poisoned food technique, we determined that the minimum inhibitory concentration of garlic oil was 0.35 μg/mL. Observation by transmission electron microscopy indicated that garlic oil could penetrate the cellular membrane of C. albicans as well as the membranes of organelles such as the mitochondria, resulting in organel...

  13. Fungal Morphogenetic Pathways Are Required for the Hallmark Inflammatory Response during Candida albicans Vaginitis

    OpenAIRE

    Peters, Brian M.; Palmer, Glen E.; Nash, Andrea K.; Lilly, Elizabeth A.; Fidel, Paul L.; Noverr, Mairi C.

    2014-01-01

    Vulvovaginal candidiasis, caused primarily by Candida albicans, presents significant health issues for women of childbearing age. As a polymorphic fungus, the ability of C. albicans to switch between yeast and hyphal morphologies is considered its central virulence attribute. Armed with new criteria for defining vaginitis immunopathology, the purpose of this study was to determine whether the yeast-to-hypha transition is required for the hallmark inflammatory responses previously characterize...

  14. 光动力疗法治疗食管癌合并白色念珠菌感染%Photodynamic Therapy for Esophageal Squamous Cell Carcinoma Associated with Candida albicans Infection

    Institute of Scientific and Technical Information of China (English)

    毛永平; 邱海霞; 顾瑛; 王颖; 朱建国; 曾晶; 刘庆森; 杨云生

    2011-01-01

    目的 观察光动力疗法抗食管真菌感染的疗效.方法 临床及病理确诊为食管癌合并食管白色念珠菌感染的患者1例,静脉注射光敏剂PSD-007 5 mg/kg后6h,以波长630nm的半导体激光(激光功率密度150 mW/cm2)出光段为3 cm的柱状光纤分节段及分次进行照射.食管癌或食管癌合并白色念珠菌感染灶处,每光斑照射30 min;单纯白色念珠菌感染灶,每光斑照射15min.观察术中和术后不良反应发生情况,根据相应标准进行近期临床疗效评价.结果 该患者共进行了3次PDT治疗,其中距门齿21 ~24 cm的食管癌2次治疗后达到完全效应,伴发的白色念珠菌感染1次治疗后治愈;距门齿25 ~28 cm念珠菌性食管炎2次治疗后治愈;距门齿35~33、33~30 cm的食管癌分别经2次和3次治疗后达到明显效应.除距门齿21 ~ 24 cm的食管癌第2次PDT治疗病变完全消失后遗留少量瘢痕外,余区未发生瘢痕,狭窄、穿孔等不良反应.结论 光动力疗法不仅能有效控制进展期食管癌,还能有效治疗食管白色念珠菌感染,具有高选择性、安全、毒副作用小、可重复应用等优点,对食管真菌感染,尤是对食管真菌感染合并食管癌的患者是一种有希望的治疗方法.%Objective To observe the ability of photodynamic therapy to deal with Candida esophagitis.Methods One patient with esophageal squamous cell carcinoma associated with Candida albicans infection confirmed by endoscopy and histopathology was included in the study. PSD-007 at 5 mg/kg body mass was intravenously injected 6 h prior to laser irradiation. A semiconductor laser emitting at 630 run was used as light source. The power density of 150 mW/cm2 was used. To lesions of esophageal squamous cell carcinoma associated with C. Albicans infection or esophageal squamous cell carcinoma alone, the exposure time of30 min and a total light dose of 270 J/cm2 was used at one light spot. To lesion with Candida

  15. Evaluation of virulence factors of Candida albicans isolated from HIV-positive individuals using HAART.

    Science.gov (United States)

    de Paula Menezes, Ralciane; de Melo Riceto, Érika Bezerra; Borges, Aércio Sebastião; de Brito Röder, Denise Von Dolingër; Dos Santos Pedroso, Reginaldo

    2016-06-01

    The colonization by Candida species is one of the most important factors related to the development of oral candidiasis in HIV-infected individuals. The aim of the study was to evaluate and discuss the phospholipase, proteinase, DNAse and haemolytic activities of Candida albicans isolated from the oral cavity of HIV individuals with high efficiency antiretroviral therapy. Seventy-five isolates of C. albicans obtained from saliva samples of patients with HIV and 41 isolates from HIV-negative individuals were studied. Haemolytic activity was determined in Sabouraud dextrose agar plates containing 3% glucose and 7% sheep red cells. Culture medium containing DNA base-agar, egg yolk, and bovine albumin were used to determine DNase, phospholipase and proteinase activities, respectively. All isolates from the HIV patients group had haemolytic activity, 98% showed phospholipase activity, 92% were positive for proteinase and 32% DNAse activity. Regarding the group of indivídios HIV negative, all 41 isolates presented hemolytic activity, 90.2% showed phospholipase and proteinase activity and 12.2% were positive for DNAse. The phospholipase activity was more intense for the group of HIV positive individuals. DNase production was more frequently observed in the group of HIV-positive individuals. The percentage of isolates having DNAse activity was also significantly different between the groups of patients not using any antiretroviral therapy, those using transcriptase inhibitors and those using transcriptase inhibitor and protease inhibitor in combination. PMID:26913969

  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. Transcriptional regulation of drug-resistance genes in Candida albicans biofilms in response to antifungals.

    Science.gov (United States)

    Watamoto, T; Samaranayake, L P; Egusa, H; Yatani, H; Seneviratne, C J

    2011-09-01

    Biofilm formation is a major virulence attribute of Candida albicans and is directly associated with therapeutic failure. One method by which Candida acquires antifungal resistance is the expression of drug-resistance genes. This study aimed to evaluate the transcriptional regulation of several genes associated with antifungal resistance of C. albicans under planktonic, recently adhered and biofilm growth modes and in C. albicans biofilms in response to antifungal agents. Initially, the antifungal susceptibility of C. albicans cultures in different growth modes was evaluated by standard antifungal susceptibility testing. Next, to assess CDR1, CDR2, MDR1, ERG11, FKS1 and PIL1 expression, RNA was harvested from cells in each growth mode, and from biofilms after drug treatment, and subjected to quantitative real-time RT-PCR (qRT-PCR). Biofilm C. albicans was more resistant to antifungals than recently adhered cells and stationary-phase planktonic cultures. Transcriptional expression of CDR1, CDR2, MDR1, ERG11 and FKS1 was lower in recently adhered C. albicans than in the stationary-phase planktonic cultures. In contrast, PIL1 levels were significantly increased in recently adhered and biofilm modes of growth. The expression of MDR1 in biofilms greatly increased on challenge with amphotericin B but not with the other drugs tested (PERG11 was significantly upregulated by ketoconazole (PCandida biofilms, and lay a foundation for future large-scale genome-wide expression analysis. PMID:21474609

  18. 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.

  19. Expression of UME6, a Key Regulator of Candida albicans Hyphal Development, Enhances Biofilm Formation via Hgc1- and Sun41-Dependent Mechanisms

    OpenAIRE

    Banerjee, Mohua; Uppuluri, Priya; Zhao, Xiang R.; Carlisle, Patricia L.; Vipulanandan, Geethanjali; Villar, Cristina C.; López-Ribot, José L.; Kadosh, David

    2013-01-01

    Biofilm formation is associated with the ability of Candida albicans, the major human fungal pathogen, to resist antifungal therapies and grow on tissues, catheters, and medical devices. In order to better understand the relationship between C. albicans morphology and biofilm formation, we examined biofilms generated in response to expression of UME6, a key filament-specific transcriptional regulator. As UME6 levels rise, C. albicans cells are known to transition from yeast to hyphae, and we ...

  20. Glucocorticoid dose determines osteocyte cell fate

    OpenAIRE

    Jia, Junjing; Yao, Wei; Guan, Min; Dai, WeiWei; Shahnazari, Mohammad; Kar, Rekha; Bonewald, Lynda; Jiang, Jean X.; Lane, Nancy E.

    2011-01-01

    In response to cellular insult, several pathways can be activated, including necrosis, apoptosis, and autophagy. Because glucocorticoids (GCs) have been shown to induce both osteocyte apoptosis and autophagy, we sought to determine whether osteocyte cell fate in the presence of GCs was dose dependent by performing in vivo and in vitro studies. Male Swiss-Webster mice were treated with slow-release prednisolone pellets at 1.4, 2.8, and 5.6 mg/kg/d for 28 d. An osteocyte cell line, MLO-Y4 cells...

  1. 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

    2013-01-01

    study of C. albicans interactions with the bacterium Pseudomonas aeruginosa, which often coinfects with C. albicans, we have found that P. aeruginosa-produced phenazines modulate C. albicans metabolism and, through these metabolic effects, impact cellular morphology, cell-cell interactions, and biofilm formation. We suggest that the structure of C. albicans biofilms promotes access to oxygen and enhances respiratory metabolism and that the perturbation of respiration by phenazines inhibits biofilm development. Our findings not only provide insight into interactions between these species but also provide valuable insights into novel pathways that could lead to the development of new therapies to treat C. albicans infections. PMID:23362320

  2. Interactions of Candida albicans with host epithelial surfaces

    OpenAIRE

    David W. Williams; Jordan, Rachael P. C.; Wei, Xiao-qing; Alves, Carlos T.; Wise, Matt P; Wilson, Melanie J.; Michael A. O. Lewis

    2013-01-01

    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 exis...

  3. Influência da co-agregação entre Candida. Albicans e Lactobacillus acidophilus na capacidade de adesão destes microrganismos às células epiteliais vaginais humanas (CEVH - doi: 10.4025/actascihealthsci.v33i1.7218 Influence of the co-aggregation between Candida. albicans e Lactobacillus acidophilus on the adhesion capacity these microorganisms in the human ephitelial vaginal cells (HEVC - doi: 10.4025/actascihealthsci.v33i1.7218

    Directory of Open Access Journals (Sweden)

    Terezinha Inez Estivalet Svidzinski

    2011-05-01

    Full Text Available Este trabalho teve por objetivo avaliar a influência da co-agregação in vitro entre Candida albicans e Lactobacillus acidophilus na capacidade de adesão destes microrganismos às células epiteliais vaginais humanas (CEVH. Foram utilizados um isolado vaginal de C. albicans e uma cepa ATCC de L. acidophilus. Uma suspensão de cada microrganismo isoladamente e do co-agregado foram incubados com as CEVH obtidas de uma doadora saudável. Foram feitos esfregaços por cristal violeta e Papanicolaou, e o número de leveduras, lactobacilos ou co-agregados aderidos às células foi contado (em 300 células superficiais-CS e 300 intermediárias-CI. A Microscopia eletrônica de varredura (MEV foi realizada em todas as situações dos ensaios. Leveduras e lactobacilos aderiram fortemente as CEVH, tanto em CS quanto em CI. A co-agregação levou a um aumento na capacidade de adesão das leveduras (p 0,05. Havendo correlação com o que acontece in vivo, probióticos à base de L. acidophillus e mesmo uma flora lactobacilar vaginal não surtiriam efeito protetor contra a adesão de C. albicans as CEVH e do possível desenvolvimento de candidíase vulvovaginal.This work has aimed to evaluate the influence of the L. acidophilus and Candida albicans co-aggregation on the adhesion capacity this microorganisms in the human ephitelial vaginal cells (HEVC. One vaginal isolated of C. albicans and one ATCC strain of L. acidophilus was used. A suspension of the isolated and co-aggregated microorganisms was incubated with HVEC obtained from a healthy donor. After one hour, smears were made with crystal violet and Papanicolaou, and the number of yeasts adhered to HVEC was evaluated (300 superficial-SC and 300 intermediate cells-IC. Scanning electron microscopy (SEM was made in all situations of the assays. Yeasts and lactobacilli adhered strongly to the HEVC, both SC and IC. The co-aggregation there was an increase in the adhesion capacity of the yeasts (p 0

  4. Determining physical properties of the cell cortex

    CERN Document Server

    Saha, A; Behrndt, M; Heisenberg, C -P; Jülicher, F; Grill, S W

    2015-01-01

    Actin and myosin assemble into a thin layer of a highly dynamic network underneath the membrane of eukaryotic cells. This network generates the forces that drive cell and tissue-scale morphogenetic processes. The effective material properties of this active network determine large-scale deformations and other morphogenetic events. For example,the characteristic time of stress relaxation (the Maxwell time)in the actomyosin sets the time scale of large-scale deformation of the cortex. Similarly, the characteristic length of stress propagation (the hydrodynamic length) sets the length scale of slow deformations, and a large hydrodynamic length is a prerequisite for long-ranged cortical flows. Here we introduce a method to determine physical parameters of the actomyosin cortical layer (in vivo). For this we investigate the relaxation dynamics of the cortex in response to laser ablation in the one-cell-stage {\\it C. elegans} embryo and in the gastrulating zebrafish embryo. These responses can be interpreted using ...

  5. Assessing the advantage of morphological changes in Candida albicans: a game theoretical study

    Directory of Open Access Journals (Sweden)

    EddaKlipp

    2014-02-01

    Full Text Available A range of attributes determines the virulence of human pathogens. During interactions with their hosts, pathogenic microbes often undergo transitions between distinct stages, and the ability to switch between these can be directly related to the disease process. Understanding the mechanisms and dynamics of these transitions is a key factor in understanding and combating infectious diseases. The human fungal pathogen Candida albicans exhibits different morphotypes at different stages during the course of infection (candidiasis. For example, hyphae are considered to be the invasive form, which causes tissue damage, while yeast cells are predominant in the commensal stage. Here, we described interactions of C. albicans with its human host in a game theoretic model. In the game, players are fungal cells. Each fungal cell can adopt one of the two strategies: to exist as a yeast or hyphal cell. We characterized the ranges of model parameters in which the coexistence of both yeast and hyphal forms is plausible. Stability analysis of the system showed that, in theory, a reduced ability of the host to specifically recognize yeast and hyphal cells can result in bi-stability of the microbial populations’ profile. Inspired by the model analysis we reasoned that the types of microbial interactions can change during invasive candidiasis. We found that positive cooperation among fungal cells occurs in mild infections and an enhanced tendency to invade the host is associated with negative cooperation. The model can easily be extended to multi-player systems with direct application to identifying individuals that enhance either positive or negative cooperation. Results of the modelling approach have potential application in developing treatment strategies.

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

    Science.gov (United States)

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

    2016-04-01

    Recent studies have shown that the transcriptional landscape of the pleiomorphic fungus Candida albicans is highly dependent upon growth conditions. Here using a dual RNA-seq approach we identified 299 C. albicans and 72 Streptococcus gordonii genes that were either upregulated or downregulated specifically as a result of co-culturing these human oral cavity microorganisms. Seventy-five C. albicans genes involved in responses to chemical stimuli, regulation, homeostasis, protein modification and cell cycle were significantly (P ≤ 0.05) upregulated, whereas 36 genes mainly involved in transport and translation were downregulated. Upregulation of filamentation-associated TEC1 and FGR42 genes, and of ALS1 adhesin gene, concurred with previous evidence that the C. albicans yeast to hypha transition is promoted by S. gordonii. Increased expression of genes required for arginine biosynthesis in C. albicans was potentially indicative of a novel oxidative stress response. The transcriptional response of S. gordonii to C. albicans was less dramatic, with only eight S. gordonii genes significantly (P ≤ 0.05) upregulated at least two-fold (glpK, rplO, celB, rplN, rplB, rpsE, ciaR and gat). The expression patterns suggest that signals from S. gordonii cause a positive filamentation response in C. albicans, whereas S. gordonii appears to be transcriptionally less influenced by C. albicans. PMID:26042999

  7. Hyphal formation of Candida albicans is controlled by electron transfer system

    International Nuclear Information System (INIS)

    Most Candida albicans cells cultured in RPMI1640 medium at 37 deg. C grow in hyphal form in aerobic conditions, but they grow in yeast form in anaerobic conditions. The hyphal growth of C. albicans was inhibited in glucose-deficient conditions. Malonic acid, an inhibitor of succinate dehydrogenase, enhanced the yeast proliferation of C. albicans, indicating that the hyphal-formation signal was derived from the glycolysis system and the signal was transmitted to the electron transfer system via the citric acid cycle. Thenoyl trifluoro acetone (TTFA), an inhibitor of the signal transmission between complex II and Co Q, significantly inhibited the hyphal growth of C. albicans. Antimycin, KCN, and oligomycin, inhibitors of complex III, IV, and V, respectively, did not inhibit the hyphal growth of C. albicans. The production of mRNAs for the hyphal formation signal was completely inhibited in anaerobic conditions. These results indicate that the electron transfer system functions upstream of the RAS1 signal pathway and activates the expression of the hyphal formation signal. Since the electron transfer system is inactivated in anaerobic conditions, C. albicans grew in yeast form in this condition

  8. Genetic organization and mRNA expression of enolase genes of Candida albicans.

    Science.gov (United States)

    Postlethwait, P; Sundstrom, P

    1995-04-01

    In previous work, we cloned a Candida albicans cDNA for the glycolytic enzyme enolase and found a single, abundant enolase transcript on Northern (RNA) blots and a single protein on immunoblots, using antiserum raised against a recombinant enolase fusion protein. Because C. albicans enolase is abundantly produced during infection and elicits strong host immune responses, the mechanisms regulating enolase production are important for understanding the growth of C. albicans in vivo. To obtain more information on enolase gene expression by C. albicans, we used the enolase cDNA clone to investigate the genetic organization of enolase genes and the steady-state levels of enolase mRNA under several growth conditions. Gene disruption techniques in combination with Southern blot analyses of genomic DNA showed the presence of two enolase gene loci that could be distinguished by the locations of ClaI and Mn/I sites in their 3' flanking regions. Enolase steady-state mRNA levels were greatest during the middle phase of the logarithmic growth curve and were low during stationary phase. Minimal differences in enolase mRNA levels between yeast cells and hyphae were found. Propagation of C. albicans in glucose did not cause increased enolase mRNA levels compared with growth in a nonfermentable carbon source (pyruvate). It was concluded that two gene loci exist for C. albicans enolase and that enolase mRNA is constitutively produced at high levels during active metabolism. PMID:7896700

  9. Action of Coriandrum sativum L. Essential Oil upon Oral Candida albicans Biofilm Formation

    Directory of Open Access Journals (Sweden)

    V. F. Furletti

    2011-01-01

    Full Text Available The efficacy of extracts and essential oils from Allium tuberosum, Coriandrum sativum, Cymbopogon martini, Cymbopogon winterianus, and Santolina chamaecyparissus was evaluated against Candida spp. isolates from the oral cavity of patients with periodontal disease. The most active oil was fractionated and tested against C. albicans biofilm formation. The oils were obtained by water-distillation and the extracts were prepared with macerated dried plant material. The Minimal Inhibitory Concentration—MIC was determined by the microdilution method. Chemical characterization of oil constituents was performed using Gas Chromatography and Mass Spectrometry (GC-MS. C. sativum activity oil upon cell and biofilm morphology was evaluated by Scanning Electron Microscopy (SEM. The best activities against planktonic Candida spp. were observed for the essential oil and the grouped F8–10 fractions from C. sativum. The crude oil also affected the biofilm formation in C. albicans causing a decrease in the biofilm growth. Chemical analysis of the F8–10 fractions detected as major active compounds, 2-hexen-1-ol, 3-hexen-1-ol and cyclodecane. Standards of these compounds tested grouped provided a stronger activity than the oil suggesting a synergistic action from the major oil constituents. The activity of C. sativum oil demonstrates its potential for a new natural antifungal formulation.

  10. TOP2 gene disruption reduces drug susceptibility by increasing intracellular ergosterol biosynthesis in Candida albicans.

    Science.gov (United States)

    Zheng, Hao; Jiang, Yuan-Ying; Wang, Yan; Jia, Xin-Ming; Yan, Tian-Hua; Gao, Ping-Hui; Yan, Lan; Jiang, Ling-Huo; Ji, Hui; Cao, Yong-Bing

    2010-07-01

    In this study the role of the TOP2 gene in fungal drug susceptibility was investigated by disrupting and overexpressing the gene in Candida albicans. MIC determination and a spot assay showed that a top2Delta/Delta null mutant (strain T2bc) was more resistant to the antifungals tested than the wild-type (strain CAI4). Real-time RT-PCR and rhodamine 6G efflux examination showed that TOP2 did not influence the activity of drug efflux pumps. Sterol analysis with GC/high-resolution MS indicated that the intracellular ergosterol composition of the top2Delta/Delta mutant was significantly increased. Subsequently, fluorescence polarization measurements also revealed that Top2-deprived cells displayed a decrease in membrane fluidity, resulting in enhanced passive diffusion of the drugs. Quantitative real-time RT-PCR analysis further confirmed that the ERG11 gene, an essential gene in ergosterol biosynthesis, was upregulated. These results demonstrate a close relationship between the TOP2 gene and drug susceptibility in C. albicans. PMID:20223895

  11. Determinants of public T cell responses

    Institute of Scientific and Technical Information of China (English)

    Hanjie Li; Congting Ye; Guoli Ji; Jiahuai Han

    2012-01-01

    Historically,sharing T cell receptors (TCRs) between individuals has been speculated to be impossible,considering the dramatic discrepancy between the potential enormity of the TCR repertoire and the limited number of T cells generated in each individual.However,public T cell response,in which multiple individuals share identical TCRs in responding to a same antigenic epitope,has been extensively observed in a variety of immune responses across many species.Public T cell responses enable individuals within a population to generate similar antigen-specific TCRs against certain ubiquitous pathogens,leading to favorable biological outcomes.However,the relatively concentrated feature of TCR repertoire may limit T cell response in a population to some other pathogens.It could be a great benefit for human health if public T cell responses can be manipulated.Therefore,the mechanistic insight of public TCR generation is important to know.Recently,high-throughput DNA sequencing has revolutionized the study of immune receptor repertoires,which allows a much better understanding of the factors that determine the overlap of TCR repertoire among individuals.Here,we summarize the current knowledge on public T-cell response and discuss future challenges in this field.

  12. Manipulation of Host Diet To Reduce Gastrointestinal Colonization by the Opportunistic Pathogen Candida albicans.

    Science.gov (United States)

    Gunsalus, Kearney T W; Tornberg-Belanger, Stephanie N; Matthan, Nirupa R; Lichtenstein, Alice H; Kumamoto, Carol A

    2016-01-01

    Candida albicans, the most common human fungal pathogen, can cause systemic infections with a mortality rate of ~40%. Infections arise from colonization of the gastrointestinal (GI) tract, where C. albicans is part of the normal microflora. Reducing colonization in at-risk patients using antifungal drugs prevents C. albicans-associated mortalities. C. albicans provides a clinically relevant system for studying the relationship between diet and the microbiota as it relates to commensalism and pathogenicity. As a first step toward a dietary intervention to reduce C. albicans GI colonization, we investigated the impact of dietary lipids on murine colonization by C. albicans. Coconut oil and its constituent fatty acids have antifungal activity in vitro; we hypothesized that dietary coconut oil would reduce GI colonization by C. albicans. Colonization was lower in mice fed a coconut oil-rich diet than in mice fed diets rich in beef tallow or soybean oil. Switching beef tallow-fed mice to a coconut oil diet reduced preexisting colonization. Coconut oil reduced colonization even when the diet also contained beef tallow. Dietary coconut oil also altered the metabolic program of colonizing C. albicans cells. Long-chain fatty acids were less abundant in the cecal contents of coconut oil-fed mice than in the cecal contents of beef tallow-fed mice; the expression of genes involved in fatty acid utilization was lower in C. albicans from coconut oil-fed mice than in C. albicans from beef tallow-fed mice. Extrapolating to humans, these findings suggest that coconut oil could become the first dietary intervention to reduce C. albicans GI colonization. IMPORTANCE Candida albicans, the most common human fungal pathogen, can cause infections with a mortality rate of ~40%. C. albicans is part of the normal gut flora, but when a patient's immune system is compromised, it can leave the gut and cause infections. By reducing the amount of C. albicans in the gut of susceptible

  13. A Candida albicans PeptideAtlas

    OpenAIRE

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

    2014-01-01

    Candida albicans public proteomic datasets, though growing steadily in the last few years, still have a very limited presence in online repositories. We report here the creation of a C. albicans PeptideAtlas comprising near 22,000 distinct peptides at a 0.24% False Discovery Rate (FDR) that account for over 2500 canonical proteins at a 1.2% FDR. Based on data from 16 experiments, we attained coverage of 41% of the C. albicans open reading frame sequences (ORFs) in the database used for the se...

  14. Candida albicans chronic colonisation in cystic fibrosis may be associated with inhaled antibiotics.

    Science.gov (United States)

    Noni, Maria; Katelari, Anna; Kaditis, Athanasios; Theochari, Ioanna; Lympari, Ioulia; Alexandrou-Athanassoulis, Helen; Doudounakis, Stavros-Eleftherios; Dimopoulos, George

    2015-07-01

    Candida albicans is increasingly recognised as a coloniser of the respiratory tract in cystic fibrosis (CF) patients. Yet, the potential role, if any, of the micro-organism in the progress of the disease remains unclear. In this study, we investigated the association between inhaled antibiotics and C. albicans chronic colonisation in patients with CF. A cohort of 121 CF patients born from 1988 to 1996 was, respectively, studied. The medical records of each patient were reviewed from the first time they attended the CF Centre until the occurrence of C. albicans chronic colonisation or their last visit for the year 2010. Chronic colonisation was defined as the presence of C. albicans in more than 50% of cultures in a given year. A number of possible confounders were included in the multivariate logistic regression analysis to identify an independent association between inhaled antibiotics and C. albicans chronic colonisation. Fifty-four (44.6%) of the 121 patients enrolled in the study developed chronic colonisation by the micro-organism. Multivariate logistic regression analysis determined the independent effect of inhaled antibiotic treatment on the odds of chronic colonisation (OR 1.112, 95% CI [1.007-1.229], P = 0.036). Candida albicans chronic colonisation may be associated with the duration of inhaled antibiotic treatment. PMID:26058475

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

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    Moran, Gary P; Coleman, David C.; Sullivan, Derek J.

    2011-01-01

    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 pseudogenisa...

  17. Host defence against C. albicans infections in IgH transgenic mice with V(H) derived from a natural anti-keratin antibody.

    Science.gov (United States)

    Li, Wei; Fu, Meng; An, Jin-Gang; Xing, Ying; Zhang, Ping; Zhang, Xin; Wang, Yao-Chun; Li, Cheng-Xin; Tian, Rong; Su, Wen-Jing; Guan, Hai-Hong; Wang, Gang; Gao, Tian-Wen; Han, Hua; Liu, Yu-Feng

    2007-02-01

    Fungal infections have been increasing and life-threatening in recent years, but host immune responses, especially the humoral immunity, to fungi have not been fully understood. In the present study, we report that natural antibodies from unimmunized mice bind to Candida albicans. We established a monoclonal natural antibody, 3B4, which recognized a surface antigen located at germ tubes of C. albicans. The 3B4 antibody protected mice from C. albicans-induced death in passive immunization, by mechanisms involving suppressing germ tube formation and modulating phagocytosis. Interestingly, 3B4 also bound to a self-antigen keratin. To further study the generation and anti-C. albicans activities of natural antibodies in vivo, we constructed a mu chain transgenic mouse (TgV(H)3B4) using the V(H) gene from 3B4. TgV(H)3B4 had elevated serum anti-keratin/C. albicans IgM, and were resistant to C. albicans infections. Analyses of B cell development showed that in TgV(H)3B4, B cells secreting the anti-keratin/C. albicans antibodies were enriched in the B1 B cell compartment. Our findings reveal an important role of keratin-reactive natural antibodies in anti-C. albicans immune responses, and suggest that keratin may function in selecting B cells into the B1 B cell compartment, where natural antibodies are made to fight fungal infections. PMID:16925788

  18. Transcriptional response to fluconazole and amphotericin B in Candida albicans biofilms.

    Science.gov (United States)

    Nailis, Heleen; Vandenbosch, Davy; Deforce, Dieter; Nelis, Hans J; Coenye, Tom

    2010-05-01

    Biofilm formation is often associated with persistent Candida albicans infections. Treatment of these infections is difficult, since sessile C. albicans cells show increased resistance towards antifungal agents. The molecular mechanisms behind biofilm resistance in C. albicans are not yet understood. In the present study, we investigated the transcriptional response in young and mature in vitro-grown biofilms after a short and longer exposure time to high doses of fluconazole or amphotericin B. Treatment of biofilms with high doses of antifungal agents resulted in a drug-specific transcriptional response. Exposure of biofilms to fluconazole induced upregulation of genes encoding enzymes involved in ergosterol biosynthesis (ERG1, ERG3, ERG11 and ERG25). Treatment of biofilms with amphotericin B resulted in an overexpression of KRE1 and SKN1, two genes encoding proteins involved in beta-1,6-glucan biosynthesis. Our data indicate that sessile C. albicans cells show controlled regulation of gene expression, as they quickly mount a drug-specific transcriptional response in the presence of high doses of antifungal agents. These transcriptional changes suggest upregulation of ergosterol biosynthesis (fluconazole) and upregulation of beta-1,6-glucan biosynthesis (amphotericin B) in sessile C. albicans cells that might contribute to a resistant biofilm phenotype. PMID:20170727

  19. 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.

  20. Urinary tract infections and Candida albicans

    OpenAIRE

    BEHZADI, Payam; BEHZADI, Elham; Ranjbar, Reza

    2015-01-01

    Introduction Urinary tract candidiasis is known as the most frequent nosocomial fungal infection worldwide. Candida albicans is the most common cause of nosocomial fungal urinary tract infections; however, a rapid change in the distribution of Candida species is undergoing. Simultaneously, the increase of urinary tract candidiasis has led to the appearance of antifungal resistant Candida species. In this review, we have an in depth look into Candida albicans uropathogenesis and distribution o...

  1. The diploid genome sequence of Candida albicans

    OpenAIRE

    Jones, Ted; Federspiel, Nancy A.; Chibana, Hiroji; Dungan, Jan; Kalman, Sue; Magee, B. B.; Newport, George; Thorstenson, Yvonne R.; Agabian, Nina; Magee, P T; Davis, Ronald W.; Scherer, Stewart

    2004-01-01

    We present the diploid genome sequence of the fungal pathogen Candida albicans. Because C. albicans has no known haploid or homozygous form, sequencing was performed as a whole-genome shotgun of the heterozygous diploid genome in strain SC5314, a clinical isolate that is the parent of strains widely used for molecular analysis. We developed computational methods to assemble a diploid genome sequence in good agreement with available physical mapping data. We provide a whole-genome description ...

  2. Vacuolar trafficking and Candida albicans pathogenesis

    OpenAIRE

    Palmer, Glen E.

    2011-01-01

    The vacuole is likely to play a variety of roles in supporting host colonization and infection by pathogenic species of fungi. In the human pathogen Candida albicans, the vacuole undergoes dynamic morphological shifts during the production of the tissue invasive hyphal form, and this organelle is required for virulence. Recent efforts in my lab have focused on defining which vacuolar trafficking pathways are required for C. albicans hyphal growth and pathogenesis. Our results indicate that th...

  3. Characterization of Mucosal Candida albicans Biofilms

    OpenAIRE

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

    2009-01-01

    C. albicans triggers recurrent infections of the alimentary tract mucosa that result from biofilm growth. Although the ability of C. albicans to form a biofilm on abiotic surfaces has been well documented in recent years, no information exists on biofilms that form directly on mucosal surfaces. The objectives of this study were to characterize the structure and composition of Candida biofilms forming on the oral mucosa. We found that oral Candida biofilms consist of yeast, hyphae, and commens...

  4. Triclosan antagonises fluconazole activity against Candida albicans

    OpenAIRE

    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 cdr1? and cdr2? strains. Triclosan did not affect fluconazole uptake or alter total m...

  5. Triclosan Antagonizes Fluconazole Activity against Candida albicans

    OpenAIRE

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

    2012-01-01

    Triclosan is a broad-spectrum antimicrobial compound commonly used in oral hygiene products. Investigation of its activity against Candida albicans showed that triclosan was fungicidal at concentrations of 16 mg/L. However, at subinhibitory concentrations (0.5-2 mg/L), triclosan antagonized the activity of fluconazole. Although triclosan induced CDR1 expression in C. albicans, antagonism was still observed in cdr1Δ and cdr2Δ strains. Triclosan did not affect fluconazole uptake or alter total ...

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

    Directory of Open Access Journals (Sweden)

    Anna Murzyn

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

  7. 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.

  8. Determining Physical Properties of the Cell Cortex.

    Science.gov (United States)

    Saha, Arnab; Nishikawa, Masatoshi; Behrndt, Martin; Heisenberg, Carl-Philipp; Jülicher, Frank; Grill, Stephan W

    2016-03-29

    Actin and myosin assemble into a thin layer of a highly dynamic network underneath the membrane of eukaryotic cells. This network generates the forces that drive cell- and tissue-scale morphogenetic processes. The effective material properties of this active network determine large-scale deformations and other morphogenetic events. For example, the characteristic time of stress relaxation (the Maxwell time τM) in the actomyosin sets the timescale of large-scale deformation of the cortex. Similarly, the characteristic length of stress propagation (the hydrodynamic length λ) sets the length scale of slow deformations, and a large hydrodynamic length is a prerequisite for long-ranged cortical flows. Here we introduce a method to determine physical parameters of the actomyosin cortical layer in vivo directly from laser ablation experiments. For this we investigate the cortical response to laser ablation in the one-cell-stage Caenorhabditis elegans embryo and in the gastrulating zebrafish embryo. These responses can be interpreted using a coarse-grained physical description of the cortex in terms of a two-dimensional thin film of an active viscoelastic gel. To determine the Maxwell time τM, the hydrodynamic length λ, the ratio of active stress ζΔμ, and per-area friction γ, we evaluated the response to laser ablation in two different ways: by quantifying flow and density fields as a function of space and time, and by determining the time evolution of the shape of the ablated region. Importantly, both methods provide best-fit physical parameters that are in close agreement with each other and that are similar to previous estimates in the two systems. Our method provides an accurate and robust means for measuring physical parameters of the actomyosin cortical layer. It can be useful for investigations of actomyosin mechanics at the cellular-scale, but also for providing insights into the active mechanics processes that govern tissue-scale morphogenesis. PMID

  9. Binding Force Dynamics of Streptococcus mutans-glucosyltransferase B to Candida albicans.

    Science.gov (United States)

    Hwang, G; Marsh, G; Gao, L; Waugh, R; Koo, H

    2015-09-01

    Candida albicans cells are often detected with Streptococcus mutans in plaque biofilms from children affected with early childhood caries. The coadhesion between these 2 organisms appears to be largely mediated by the S. mutans-derived exoenzyme glucosyltransferase B (GtfB); GtfB readily binds to C. albicans cells in an active form, producing glucans locally that provide enhanced binding sites for S. mutans. However, knowledge is limited about the mechanisms by which the bacterial exoenzyme binds to and functions on the fungal surface to promote this unique cross-kingdom interaction. In this study, we use atomic force microscopy to understand the strength and binding dynamics modulating GtfB-C. albicans adhesive interactions in situ. Single-molecule force spectroscopy with GtfB-functionalized atomic force microscopy tips demonstrated that the enzyme binds with remarkable strength to the C. albicans cell surface (~2 nN) and showed a low dissociation rate, suggesting a highly stable bond. Strikingly, the binding strength of GtfB to the C. albicans surface was ~2.5-fold higher and the binding stability, ~20 times higher, as compared with the enzyme adhesion to S. mutans. Furthermore, adhesion force maps showed an intriguing pattern of GtfB binding. GtfB adhered heterogeneously on the surface of C. albicans, showing a higher frequency of adhesion failure but large sections of remarkably strong binding forces, suggesting the presence of GtfB binding domains unevenly distributed on the fungal surface. In contrast, GtfB bound uniformly across the S. mutans cell surface with less adhesion failure and a narrower range of binding forces (vs. the C. albicans surface). The data provide the first insights into the mechanisms underlying the adhesive and mechanical properties governing GtfB interactions with C. albicans. The strong and highly stable GtfB binding to C. albicans could explain, at least in part, why this bacterially derived exoenzyme effectively modulates this

  10. 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…

  11. Mechanistic aspects of the photodynamic inactivation of Candida albicans induced by cationic porphyrin derivatives.

    Science.gov (United States)

    Quiroga, Ezequiel D; Cormick, M Paula; Pons, Patricia; Alvarez, M Gabriela; Durantini, Edgardo N

    2012-12-01

    Photodynamic inactivation of Candida albicans produced by 5-(4-trifluorophenyl)-10,15,20-tris(4-N,N,N-trimethylammoniumphenyl)porphyrin (TFAP(3+)), 5,10,15,20-tetrakis(4-N,N,N-trimethylammoniumphenyl)porphyrin (TMAP(4+)) and 5,10,15,20-tetrakis(4-N-methylpyridyl)porphyrin (TMPyP(4+)) was investigated to obtain insight about the mechanism of cellular damage. In solution, absorption spectroscopic studies showed that these cationic porphyrins interact strongly with calf thymus DNA. The electrophoretic analysis indicated that photocleavage of DNA induced by TFAP(3+) took place after long irradiation periods (>5 h). In contrast, TMAP(4+) produced a marked reduction in DNA band after 1 h irradiation. In C. albicans, these cationic porphyrins produced a ∼3.5 log decrease in survival when the cell suspensions (10(7) cells/mL) were incubated with 5 μM photosensitizer and irradiated for 30 min with visible light (fluence 162 J/cm(2)). After this treatment, modifications of genomic DNA isolated from C. albicans cells were not found by electrophoresis. Furthermore, transmission electron microscopy showed structural changes with appearance of low density areas into the cells and irregularities in cell barriers. However, the photodamage to the cell envelope was insufficient to cause the release of intracellular biopolymers. Therefore, modifications in the cytoplasmic biomolecules and alteration in the cell barriers could be mainly involved in C. albicans photoinactivation. PMID:23142673

  12. Design of a Simple Model of Candida albicans Biofilms Formed under Conditions of Flow: Development, Architecture and Drug Resistance

    OpenAIRE

    Uppuluri, Priya; Chaturvedi, Ashok K.; Ribot, Jose Lopez

    2009-01-01

    Candida albicans biofilms on most medical devices are exposed to a flow of body fluids that provide water and nutrients to the fungal cells. While C. albicans biofilms grown in vitro under static conditions have been exhaustively studied, the same is not true for biofilms developed under continuous flow of replenishing nutrients. Here, we describe a simple flow biofilm (FB) model that can be built easily with materials commonly available in most microbiological laboratories. We demonstrate th...

  13. Discovering the Secrets of the Candida albicans Agglutinin-Like Sequence (ALS) Gene Family—a Sticky Pursuit

    OpenAIRE

    HOYER, LOIS L.; GREEN, CLAYTON B.; Oh, Soon-Hwan; Zhao, Xiaomin

    2008-01-01

    The Agglutinin-Like Sequence (ALS) family of Candida albicans includes eight genes that encode large cell-surface glycoproteins. The high degree of sequence relatedness between the ALS genes and the tremendous allelic variability often present in the same C. albicans strain complicated definition and characterization of the gene family. The main hypothesis driving ALS family research is that the genes encode adhesins, primarily involved in host-pathogen interactions. Although adhesive functio...

  14. Candida albicans Als3p is required for wild-type biofilm formation on silicone elastomer surfaces

    OpenAIRE

    Zhao, Xiaomin; Daniels, Karla J.; Oh, Soon-Hwan; GREEN, CLAYTON B.; Yeater, Kathleen M; Soll, David R.; Hoyer, Lois L.

    2006-01-01

    Candida albicans ALS3 encodes a large cell-surface glycoprotein that has adhesive properties. Immunostaining of cultured C. albicans germ tubes showed that Als3p is distributed diffusely across the germ tube surface. Two-photon laser scanning microscopy of model catheter biofilms grown using a PALS3-green fluorescent protein (GFP) reporter strain showed GFP production in hyphae throughout the biofilm structure while biofilms grown using a PTPI1-GFP reporter strain showed GFP in both hyphae an...

  15. Hydrophobic surface protein masking by the opportunistic fungal pathogen Candida albicans.

    OpenAIRE

    Hazen, K C; Hazen, B W

    1992-01-01

    Ultrastructural and biochemical analyses of hydrophobic and hydrophilic yeast cell surface proteins of Candida albicans were performed. Hydrophobic and hydrophilic yeast cells were obtained by growth at 23 and 37 degrees C, respectively. In addition, hydrophilic yeast cells were converted to surface hydrophobicity by treatment with tunicamycin and dithiothreitol. When freeze-etched cells were examined, the temperature-induced hydrophilic cells had long (0.198 micron), compact, evenly distribu...

  16. 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.

  17. Adherence of Streptococcus mutans and Candida albicans to different bracket materials

    Directory of Open Access Journals (Sweden)

    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.

  18. Candida albicans modulates host defense by biosynthesizing the pro-resolving mediator resolvin E1.

    Directory of Open Access Journals (Sweden)

    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.

  19. Systemic non-albicans infections presented as meningitis in chronic hepatitis B patient: a case report

    Directory of Open Access Journals (Sweden)

    Wen-Jing Lv

    2014-12-01

    Full Text Available Non-albicans candida meningitis is a relatively rare disease, with nonspecific clinical manifestation, which makes the misdiagnosis occur sometimes, especially in the early stage of the disease. Abuse of broad-spectrum antibiotics, corticosteroids, central vein cannulas, senility, big operation, malignancy, and total parenteral alimentation were all the susceptible factors of non-albicans candida infection. We present a case of this type of non-albicans infection in a 42-year-old woman who was early misdiagnosed as tuberculous meningitis and was treated with antibiotics and antituberculosis agents. The diagnosis of non-albicans infection was confirmed by fungus culture of the cerebrospinal fluid (CSF with a low detectable rate. This case reminds us that the non-albicans candida meningitis had a nonspecific clinical presentations and laboratory data, and was difficult to differentiate from tuberculosis meningitis. Hence, we should highly suspect this disease if central nervous system infections with uncertain pathogens. Test cell counts; protein and fungus culture of CSF should be used to confirm the diagnosis. Once the diagnosis was established, the patients should receive antifungal treatment based on drug sensitivity tests as early as possible.

  20. Disruption of the ECM33 gene in Candida albicans prevents biofilm formation, engineered human oral mucosa tissue damage and gingival cell necrosis/apoptosis.

    Science.gov (United States)

    Rouabhia, Mahmoud; Semlali, Abdelhabib; Chandra, Jyotsna; Mukherjee, Pranab; Chmielewski, Witold; Ghannoum, Mahmoud A

    2012-01-01

    In this study we demonstrated that ΔCaecm33 double mutant showed reduced biofilm formation and causes less damage to gingival mucosa tissues. This was confirmed by the reduced level of necrotic cells and Bax/Bcl2 gene expression as apoptotic markers. In contrast, parental and Caecm33 mutant strains decreased basement membrane protein production (laminin 5 and type IV collagen). We thus propose that ECM33 gene/protein represents a novel target for the prevention and treatment of infections caused by Candida. PMID:22665950

  1. Functional diversity of complex I subunits in Candida albicans mitochondria.

    Science.gov (United States)

    Li, Dongmei; She, Xiaodong; Calderone, Richard

    2016-02-01

    Our interest in the mitochondria of Candida albicans has progressed to the identification of several proteins that are critical to complex I (CI) activity. We speculated that there should be major functional differences at the protein level between mammalian and fungal mitochondria CI. In our pursuit of this idea, we were helped by published data of CI subunit proteins from a broad diversity of species that included two subunit proteins that are not found in mammals. These subunit proteins have been designated as Nuo1p and Nuo2p (NADH-ubiquinone oxidoreductases). Since functional assignments of both C. albicans proteins were unknown, other than having a putative NADH-oxidoreductase activity, we constructed knock-out strains that could be compared to parental cells. The relevance of our research relates to the critical roles of both proteins in cell biology and pathogenesis and their absence in mammals. These features suggest they may be exploited in antifungal drug discovery. Initially, we characterized Goa1p that apparently regulates CI activity but is not a CI subunit protein. We have used the goa1∆ for comparisons to Nuo1p and Nuo2p. We have demonstrated the critical role of these proteins in maintaining CI activities, virulence, and prolonging life span. More recently, transcriptional profiling of the three mutants and an ndh51∆ (protein is a highly conserved CI subunit) has revealed that there are overlapping yet also different functional assignments that suggest subunit specificity. The differences and similarities of each are described below along with our hypotheses to explain these data. Our conclusion and perspective is that the C. albicans CI subunit proteins are highly conserved except for two that define non-mammalian functions. PMID:26373419

  2. The Role of Autophagy-Related Proteins in Candida albicans Infections.

    Science.gov (United States)

    Tam, Jenny M; Mansour, Michael K; Acharya, Mridu; Sokolovska, Anna; Timmons, Allison K; Lacy-Hulbert, Adam; Vyas, Jatin M

    2016-01-01

    Autophagy plays an important role in maintaining cell homeostasis by providing nutrients during periods of starvation and removing damaged organelles from the cytoplasm. A marker in the autophagic process is the reversible conjugation of LC3, a membrane scaffolding protein, to double membrane autophagosomes. Recently, a role for LC3 in the elimination of pathogenic bacteria and fungi, including Candida albicans (C. albicans), was demonstrated, but these organisms reside in single membrane phagosomes. This process is distinct from autophagy and is termed LC3-associated phagocytosis (LAP). This review will detail the hallmarks of LAP that distinguish it from classical autophagy and review the role of autophagy proteins in host response to C. albicans and other pathogenic fungi. PMID:27043636

  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. Comparison Between Virulence Factors of Candida albicans and Non-Albicans Species of Candida Isolated from Genitourinary Tract

    OpenAIRE

    Udayalaxmi,; Jacob, Shani; D’Souza, Diney

    2014-01-01

    Background: Candida spp. is frequently isolated from cases of vulvovaginal candidiasis and catheter associated UTI. C.albicans is the most frequently isolated species but non-albicans species of candida are gaining clinical significance.

  5. Production of a hemolytic factor by Candida albicans.

    OpenAIRE

    Manns, J M; MOSSER, D. M.; Buckley, H R

    1994-01-01

    Candida albicans exhibits hemolytic activity when grown on glucose-enriched blood agar. This activity is present on intact organisms, and it is secreted into the culture medium. Hemoglobin released from lysed erythrocytes can restore the transferrin-inhibited growth of C. albicans. We conclude that C. albicans expresses a hemolytic factor which allows it to acquire iron from host erythrocytes.

  6. Mechanism of iron uptake by the pathogenic yeast, Candida albicans

    International Nuclear Information System (INIS)

    C. albicans requires iron for growth and phenotypic development. When deprived of iron, mycelium and bud formation was suppressed. Survival of the organism was also reduced under iron-limiting conditions. The combination of elevated temperature and iron-deprivation further reduced phenotypic development and survival of the yeast. The combination of elevated temperature and iron starvation resulted in a decrease in both the growth rate and siderophore production. However, with time, the cells were able to show partial recovery in the growth rate which occurred concomitantly with an increase in siderophore production. In order for siderophores to be utilized, ferri-siderophore receptors must be produced. The receptor was shown to be located in the plasma membrane of the yeast. Scatchard analysis of the binding of ferri-siderophores to plasma membrane receptors showed an increase in receptor affinity and number of binding sites in iron-starved cells when compared to control cells. Autoradiograms of the 58Fe-siderophore-protein complex following SDS-PAGE separation of candidal proteins revealed the presence of a ferri-siderophore receptor of approximately 10,000 daltons. C. albicans strains which lacked the ability to synthesize phenolate siderophore maintained a phenolate receptor and bound candidal phenolate siderophore better than non-candidal phenolate siderophores

  7. Bruton's Tyrosine Kinase (BTK and Vav1 contribute to Dectin1-dependent phagocytosis of Candida albicans in macrophages.

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    Karin Strijbis

    Full Text Available Phagocytosis of the opportunistic fungal pathogen Candida albicans by cells of the innate immune system is vital to prevent infection. Dectin-1 is the major phagocytic receptor involved in anti-fungal immunity. We identify two new interacting proteins of Dectin-1 in macrophages, Bruton's Tyrosine Kinase (BTK and Vav1. BTK and Vav1 are recruited to phagocytic cups containing C. albicans yeasts or hyphae but are absent from mature phagosomes. BTK and Vav1 localize to cuff regions surrounding the hyphae, while Dectin-1 lines the full length of the phagosome. BTK and Vav1 colocalize with the lipid PI(3,4,5P3 and F-actin at the phagocytic cup, but not with diacylglycerol (DAG which marks more mature phagosomal membranes. Using a selective BTK inhibitor, we show that BTK contributes to DAG synthesis at the phagocytic cup and the subsequent recruitment of PKCε. BTK- or Vav1-deficient peritoneal macrophages display a defect in both zymosan and C. albicans phagocytosis. Bone marrow-derived macrophages that lack BTK or Vav1 show reduced uptake of C. albicans, comparable to Dectin1-deficient cells. BTK- or Vav1-deficient mice are more susceptible to systemic C. albicans infection than wild type mice. This work identifies an important role for BTK and Vav1 in immune responses against C. albicans.

  8. Horizontal transmission of Candida albicans and evidence of a vaccine response in mice colonized with the fungus.

    Directory of Open Access Journals (Sweden)

    Jim E Cutler

    Full Text Available Disseminated candidiasis is the third leading nosocomial blood stream infection in the United States and is often fatal. We previously showed that disseminated candidiasis was preventable in normal mice by immunization with either a glycopeptide or a peptide synthetic vaccine, both of which were Candida albicans cell wall derived. A weakness of these studies is that, unlike humans, mice do not have a C. albicans GI flora and they lack Candida serum antibodies. We examined the influence of C. albicans GI tract colonization and serum antibodies on mouse vaccination responses to the peptide, Fba, derived from fructose bisphosphate aldolase which has cytosolic and cell wall distributions in the fungus. We evaluated the effect of live C. albicans in drinking water and antimicrobial agents on establishment of Candida colonization of the mouse GI tract. Body mass, C. albicans in feces, and fungal-specific serum antibodies were monitored longitudinally. Unexpectedly, C. albicans colonization occurred in mice that received only antibiotics in their drinking water, provided that the mice were housed in the same room as intentionally colonized mice. The fungal strain in unintentionally colonized mice appeared identical to the strain used for intentional GI-tract colonization. This is the first report of horizontal transmission and spontaneous C. albicans colonization in mice. Importantly, many Candida-colonized mice developed serum fungal-specific antibodies. Despite the GI-tract colonization and presence of serum antibodies, the animals made antibodies in response to the Fba immunogen. This mouse model has potential for elucidating C. albicans horizontal transmission and for exploring factors that induce host defense against disseminated candidiasis. Furthermore, a combined protracted GI-tract colonization with Candida and the possibility of serum antibody responses to the presence of the fungus makes this an attractive mouse model for testing the

  9. Factors affecting colonization and dissemination of Candida albicans from the gastrointestinal tract of mice.

    OpenAIRE

    Ekenna, O; Sherertz, R J

    1987-01-01

    Male ICR Swiss mice (2 to 3 months old) were fed Candida albicans in their drinking water for 3 days, followed by no treatment, antibiotics in their drinking water (daily), or immunosuppressants given by intraperitoneal injection (two to three times weekly) over a 3- to 4-week period. The organs of animals were processed to determine the numbers of C. albicans and total aerobic bacteria per g of tissue. Untreated animals had mean Candida counts during the 1-month period of 10(2.3) CFU/g of ce...

  10. 氯生太尔体外抗白念珠菌活性的研究%In vitro antifungal activity of closantel against Candida albicans

    Institute of Scientific and Technical Information of China (English)

    陈文峰; 张子平; 程波

    2012-01-01

    目的 研究氯生太尔体外抗白念珠菌的活性.方法 用微量稀释法测定氟康唑单独及联合氯生太尔对白念珠菌标准株CAF-2的最小抑菌浓度(MIC);用含10%小牛血清的RPMI 1640液体培养基诱导菌丝形成,计算并比较实验组(氯生太尔作用后)和对照组(未加氯生太尔)10株白念珠菌菌丝的形成率;用透射及扫描电镜观察白念珠菌标准株CAF-2在氯生太尔作用后的超微结构变化.结果 氯生太尔在体外能抑制白念珠菌的生长,且与氟康唑联合用药时可以明显提高氟康唑对白念珠菌的敏感性.氯生太尔对白念珠菌的菌丝形成抑制实验,对照组见大量菌丝形成,菌丝形成率为91.2%±3.9%,氯生太尔实验组菌丝形成率为29.8%±5.1%,实验组菌丝形成率明显降低,差异有统计学意义(t=30.24,P< 0.05).透射电镜观察氯生太尔作用后的白念珠菌,细胞呈圆形、椭圆形或多形性,细胞表面出芽不规则,细胞壁外层的电子致密层分布不均匀,部分有缺失,透明层厚薄不一,部分细胞膜塌陷,局部破坏,胞内空泡增多;扫描电镜观察,氯生太尔作用后的白念珠菌,表面凹凸不平,出芽细胞少且出芽不规则.结论 氯生太尔在体外具有明显的抗白念珠菌活性.%Objective To determine the in vitro antifungal effects of closantel against Candida albicans.Methods A microdilution method was used to determine the minimum inhibitory concentration (MIC)of fluconazole alone and in combination with closantel against Candida albicans standard strain CAF-2.Ten strains of Candida albicans were cultured in RPMI-1640 liquid culture containing 10% calf serum with or without the presence of closantel at 16 mg/L,followed by the observation of hypha formation.Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were performed to observe the ultrastructure of Candida albicans CAF-2 strain after exposure to closantel at 16 mg

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

    Science.gov (United States)

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

    2016-07-01

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

  12. Perbedaan Efek Ekstrak Jintan Hitam terhadap Candida albicans Denture Stomatitis dan Candida albicans (ATCC® 10231™)

    OpenAIRE

    Carey, Steffi

    2015-01-01

    Jintan hitam mempunyai efek fungistatis dan fungisidal. Hal ini disebabkan adanya senyawa berupa timokuinon, timol, dan karvakrol. Penelitian ini bertujuan untuk mengetahui berapa konsentrasi Kadar Hambat Minimum (KHM) dan Kadar Bunuh Minimum (KBM) dari ekstrak jintan hitam terhadap Candida albicans denture stomatitis dan Candida albicans (ATCC® 10231™), serta untuk mengetahui apakah terdapat perbedaan efek ekstrak jintan hitam terhadap kedua jenis fungi tersebut. Jenis penelitian eksperiment...

  13. Regulation of T cell response to leishmania antigens by determinants of histocompatibility leukocyte class I and II molecules

    Directory of Open Access Journals (Sweden)

    Bacellar O.

    1998-01-01

    Full Text Available It has been shown that HLA class I molecules play a significant role in the regulation of the proliferation of T cells activated by mitogens and antigens. We evaluated the ability of mAb to a framework determinant of HLA class I molecules to regulate T cell proliferation and interferon gamma (IFN-g production against leishmania, PPD, C. albicans and tetanus toxoid antigens in patients with tegumentary leishmaniasis and healthy subjects. The anti-major histocompatibility complex (MHC mAb (W6/32 suppressed lymphocyte proliferation by 90% in cultures stimulated with aCD3, but the suppression was variable in cultures stimulated with leishmania antigen. This suppression ranged from 30-67% and was observed only in 5 of 11 patients. IFN-g production against leishmania antigen was also suppressed by anti-HLA class I mAb. In 3 patients IFN-g levels were suppressed by more than 60%, while in the other 2 cultures IFN-g levels were 36 and 10% lower than controls. The suppression by HLA class I mAb to the proliferative response in leishmaniasis patients and in healthy controls varied with the antigens and the patients or donors tested. To determine whether the suppression is directed at antigen presenting cells (APCs or at the responding T cells, experiments with antigen-primed non-adherent cells, separately incubated with W6/32, were performed. Suppression of proliferation was only observed when the W6/32 mAb was added in the presence of T cells. These data provide evidence that a mAb directed at HLA class I framework determinants can suppress proliferation and cytokine secretion in response to several antigens.

  14. Intracellular aspartic protease ACP of Candida albicans

    Czech Academy of Sciences Publication Activity Database

    Bauerová, Václava; Dolejší, Elena; Hrušková-Heidingsfeldová, Olga; Pichová, Iva

    Patras : University of Patras, 2007. s. 306. [General Meeting of the International Proteolysis Society /5./. 20.10.2007-24.10.2007, Patras] R&D Projects: GA ČR GA203/05/0038; GA MŠk(CZ) LC531 Institutional research plan: CEZ:AV0Z40550506 Keywords : Candida albicans * ACP Subject RIV: CE - Biochemistry

  15. Apotransferrin has a second mechanism for anticandidal activity through binding of Candida albicans.

    Science.gov (United States)

    Han, Yongmoon

    2014-02-01

    It has been reported that transferrin has antibacterial and antifungal activities via iron chelation in the environment surrounding the microbes. In the present study, we investigated whether the binding of transferrin to Candida albicans mediates growth inhibition. By using cultures that contained iron-free (apo)transferrin glycoprotein either in contact with candidal cells or separated from candidal cells by a dialysis membrane, we distinguished the growth inhibition by transferrin-cell interaction from that of simple iron chelation. Maximal growth inhibition always occurred when the apotransferrin interacted directly with the cells. Additionally, there was partial inhibition even when candidal cells were in contact with iron-saturated transferrin. Binding studies with (59)Fe(3+) radiolabeled-transferrin indicated that the apo-protein can bind to the candidal cell surface. The binding sites were saturable and it was dose dependent. Chemicals (hydrogen peroxide, dithiothreitol, sodium dodecyl sulfate) blocked transferrin binding to C. albicans, and among the three, hydrogen peroxide (HP) was the most effective for the blocking. When HP-treated yeast cells were added to the culture that was pretreated with apotransferrin, candidal cell growth increased by 5-fold as compared to the growth of HP-untreated candidal cells under apotransferrin-regulation (P mechanism of anticandidal activity that is mediated by binding to the surface of C. albicans yeast cells. PMID:24155020

  16. 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.

  17. HRMS Profile of a Hazelnut Skin Proanthocyanidin-rich Fraction with Antioxidant and Anti-Candida albicans Activities.

    Science.gov (United States)

    Piccinelli, Anna Lisa; Pagano, Imma; Esposito, Tiziana; Mencherini, Teresa; Porta, Amalia; Petrone, Anna Maria; Gazzerro, Patrizia; Picerno, Patrizia; Sansone, Francesca; Rastrelli, Luca; Aquino, Rita Patrizia

    2016-01-27

    Roasted hazelnut skins (RHS) represent a byproduct of kernel industrial processing. In this research, a RHS extract (RHS-M) and its fraction RHS-M-F3 enriched in proanthocyanidins (PAs), with antioxidant activity, were characterized in terms of total phenolic compound and PA contents. RHS-M and RHS-M-F3 showed antifungal properties against Candida albicans SC5314 (MIC2 = 3.00 and 0.10 μg/mL and MIC0 = 5.00 and 0.50 μg/mL, respectively), determined by the microbroth dilution method and Candida albicans morphological analysis. No cytotoxic effect on HEKa and HDFa cell lines was exhibited by RHS-M and RHS-M-F3. The metabolite profiling of RHS-M and RHS-M-F3 was performed by thiolysis followed by HPLC-UV-HRMS analysis and a combination of HRMS-FIA and HPLC-HRMS(n). Extract and fraction contain oligomeric PAs (mDP of 7.3 and 6.0, respectively, and DP up to 10) mainly constituted by B-type oligomers of (epi)-catechin. Also, (epi)-gallocatechin and gallate derivatives were identified as monomer units, and A-type PAs were detected as minor compounds. PMID:26739867

  18. Epithelial discrimination of commensal and pathogenic Candida albicans.

    Science.gov (United States)

    Tang, S X; Moyes, D L; Richardson, J P; Blagojevic, M; Naglik, J R

    2016-04-01

    All mucosal surfaces are lined by epithelial cells and are colonised by opportunistic microbes. In health, these opportunistic microbes remain commensal and are tolerated by the immune system. However, when the correct environmental conditions arise, these microbes can become pathogenic and need to be controlled or cleared by the immune system to prevent disease. The mechanisms that enable epithelial cells to initiate the 'danger' signals activated specifically by pathogenic microbes are critical to mucosal defence and homeostasis but are not well understood. Deciphering these mechanisms will provide essential understanding to how mucosal tissues maintain health and activate immunity, as well as how pathogens promote disease. This review focuses on the interaction of the human fungal pathogen Candida albicans with epithelial cells and the epithelial mechanisms that enable mucosal tissues to discriminate between the commensal and pathogenic state of this medically important fungus. PMID:26843519

  19. Technetium-99m labelled fluconazole and antimicrobial peptides for imaging of Candida albicans and Aspergillus fumigatus infections

    Energy Technology Data Exchange (ETDEWEB)

    Lupetti, Antonella [Department of Infectious Diseases, Leiden University Medical Center (LUMC), Leiden (Netherlands); Dipartimento di Patologia Sperimentale, Biotecnologie Mediche, Univ. di Pisa (Italy); Welling, Mick M. [Department of Radiology, Division of Nuclear Medicine, LUMC, Leiden (Netherlands); Mazzi, Ulderico [Dipartimento di Scienze Farmaceutiche, Universita degli Studi di Padova (Italy); Nibbering, Peter H. [Department of Infectious Diseases, Leiden University Medical Center (LUMC), Leiden (Netherlands); Pauwels, Ernest K.J. [Department of Radiology, Division of Nuclear Medicine, LUMC, Leiden (Netherlands); Department of Radiology, Leiden University Medical Center (LUMC) (Netherlands)

    2002-05-01

    The aim of this study was to investigate whether technetium-99m labelled fluconazole can distinguish fungal from bacterial infections. Fluconazole was labelled with {sup 99m}Tc and radiochemical analysis showed less than 5% impurities. The labelling solution was injected into animals with experimental infections. For comparison, we used two peptides for infection detection, i.e. UBI 29-41 and hLF 1-11, and human IgG, all labelled with {sup 99m}Tc. Mice were infected with Candida albicans or injected with heat-killed C. albicans or lipopolysaccharides to induce sterile inflammation. Also, mice were infected with Staphylococcus aureus or Klebsiella pneumoniae. Next, accumulation of {sup 99m}Tc-fluconazole and {sup 99m}Tc-labelled peptides/IgG at affected sites was determined scintigraphically. {sup 99m}Tc-fluconazole detected C. albicans infections (T/NT ratio=3.6{+-}0.47) without visualising bacterial infections (T/NT ratio=1.3{+-}0.04) or sterile inflammatory processes (heat-killed C. albicans: T/NT ratio=1.3{+-}0.2; lipopolysaccharide: T/NT ratio=1.4{+-}0.1). C. albicans infections were already seen within the first hour after injection of {sup 99m}Tc-fluconazole (T/NT ratio=3.1{+-}0.2). A good correlation (R{sup 2}=0.864; P<0.05) between T/NT ratios for this tracer and the number of viable C. albicans was found. Although {sup 99m}Tc-UBI 29-41 and {sup 99m}Tc-hLF 1-11 were able to distinguish C. albicans infections from sterile inflammatory processes in mice, these {sup 99m}Tc-labelled peptides did not distinguish these fungal infections from bacterial infections. It is concluded that {sup 99m}Tc-fluconazole distinguishes infections with C. albicans from bacterial infections and sterile inflammations. (orig.)

  20. 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.

  1. Reduced virulence of Candida albicans MKC1 mutants: a role for mitogen-activated protein kinase in pathogenesis.

    OpenAIRE

    Diez-Orejas, R.; Molero, G; Navarro-García, F; Pla, J; Nombela, C.; Sanchez-Pérez, M

    1997-01-01

    Deletion of the Candida albicans mitogen-activated protein kinase MKC1 gene gave rise to viable cells whose cell integrity was affected (F. Navarro-García, M. Sánchez, J. Pla, and C. Nombela, Mol. Cell. Biol. 15:2197-2206, 1995). In an experimental infection system using a murine model, the C. albicans mkc1 delta/mkc1 delta strain was found to be less pathogenic than the parental strain, as show the different time of survival, percentage of mortality, fungal load in the most representative or...

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

    Science.gov (United States)

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

    2016-05-01

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

  3. 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.

  4. The ABCs of Candida albicans Multidrug Transporter Cdr1.

    Science.gov (United States)

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

    2015-12-01

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

  5. 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.

  6. Polyketide glycosides from Bionectria ochroleuca inhibit Candida albicans biofilm formation.

    Science.gov (United States)

    Wang, Bin; You, Jianlan; King, Jarrod B; Cai, Shengxin; Park, Elizabeth; Powell, Douglas R; Cichewicz, Robert H

    2014-10-24

    One of the challenges presented by Candida infections is that many of the isolates encountered in the clinic produce biofilms, which can decrease these pathogens' susceptibilities to standard-of-care antibiotic therapies. Inhibitors of fungal biofilm formation offer a potential solution to counteracting some of the problems associated with Candida infections. A screening campaign utilizing samples from our fungal extract library revealed that a Bionectria ochroleuca isolate cultured on Cheerios breakfast cereal produced metabolites that blocked the in vitro formation of Candida albicans biofilms. A scale-up culture of the fungus was undertaken using mycobags (also known as mushroom bags or spawn bags), which afforded four known [TMC-151s C-F (1-4)] and three new [bionectriols B-D (5-7)] polyketide glycosides. All seven metabolites exhibited potent biofilm inhibition against C. albicans SC5314, as well as exerted synergistic antifungal activities in combination with amphotericin B. In this report, we describe the structure determination of the new metabolites, as well as compare the secondary metabolome profiles of fungi grown in flasks and mycobags. These studies demonstrate that mycobags offer a useful alternative to flask-based cultures for the preparative production of fungal secondary metabolites. PMID:25302529

  7. Hubungan Kadar Glukosa Darah dengan Pertumbuhan Candida Albicans pada Penderita Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Sri Hernawati

    2015-10-01

    Full Text Available Diabetes mellitus is comma only hereditary metabolic disorder. The signs were hyperglycemic and glucosuric with or without acute or chronic clinically symptoms. It was cause effectively insulin deficiency. The primary was carbohydrate metabolism disorder which followed lipid and protein metabolism disorders. The increase of boold. Glucose conentration could increase salivary glucose concentration. Glucose was a good media for the growth of microorganism, for example: candida albicans. The most frequently infection on oral mucous diabetes mellitus patients was candidacies. The purpose of the study was to determine the relation of blood glucose concentration and C. albicans growth on oral cavity diabetes mellitus patients. The subject consisted of 8 non regulated diabetes mellitus, 8 regulated diabetes mellitus, and 8 normal patients, respectively. The assessment of blood glucose concentration used Bio-Rad Diastat Halmoglobine A1c method. The growth of C. albicans was determined using swab on oral mucous. The result of swab was into culated on sabaurond agar, than gram stining and glucose test was done. Data was analyzed using spearman test. The result indicated that the growth of C. albicans was eughen on non regulated diabetes mellitus than regulated diabetes mellitus. It's also on regulated diabetes mellitus that normal patient.

  8. Effect of Shark Liver Oil on Peritoneal Murine Macrophages in Responses to Killed-Candida albicans

    Directory of Open Access Journals (Sweden)

    Monire Hajimoradi

    2009-09-01

    Full Text Available Objective(sShark Liver Oil (SLO is an immunomodulator. Macrophages play a key role in host defense against pathogens like fungi. Candida albicans have mechanisms to escape immune system. We determined the effect of killed-Candida on the in vitro viability of macrophages and the effect of SLO on augmentation of this potency.Materials and MethodsPeritoneal macrophages were separated and cultured (3×105/well. At first, the effect of killed-Candida (200 cells/well on macrophage viability was evaluated, using MTT test. Then, MTT was performed on macrophages stimulated with killed-Candida in the presence of SLO. ResultsKilled-Candida suppressed the ability of MTT reduction and hence macrophages viability (P=0.026, but addition of SLO (100 mg/ml significantly enhanced cell viability (P=0.00. So, SLO could neutralize the inhibitory effect of Candida.ConclusionSimultaneous with cytotoxic effect of killed-Candida cells on macrophages viability, SLO augment macrophages viability. So, it can be applied in candidiasis as a complement.

  9. Metal Ions May Suppress or Enhance Cellular Differentiation in Candida albicans and Candida tropicalis Biofilms▿ †

    OpenAIRE

    Harrison, Joe J.; Ceri, Howard; Yerly, Jerome; Rabiei, Maryam; Hu, Yaoping; Martinuzzi, Robert; Turner, Raymond J.

    2007-01-01

    Candida albicans and Candida tropicalis are polymorphic fungi that develop antimicrobial-resistant biofilm communities that are characterized by multiple cell morphotypes. This study investigated cell type interconversion and drug and metal resistance as well as community organization in biofilms of these microorganisms that were exposed to metal ions. To study this, Candida biofilms were grown either in microtiter plates containing gradient arrays of metal ions or in the Calgary Biofilm Devi...

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

    OpenAIRE

    Iwan Hernawan; Desiana Radithia; Priyo Hadi; Diah Savitri Ernawati

    2015-01-01

    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...

  11. Live Candida albicans Suppresses Production of Reactive Oxygen Species in Phagocytes▿ †

    OpenAIRE

    Wellington, Melanie; Dolan, Kristy; Krysan, Damian J.

    2008-01-01

    Production of reactive oxygen species (ROS) is an important aspect of phagocyte-mediated host responses. Since phagocytes play a crucial role in the host response to Candida albicans, we examined the ability of Candida to modulate phagocyte ROS production. ROS production was measured in the murine macrophage cell line J774 and in primary phagocytes using luminol-enhanced chemiluminescence. J774 cells, murine polymorphonuclear leukocytes (PMN), human monocytes, and human PMN treated with live ...

  12. Inborn errors of mucocutaneous immunity to Candida albicans in humans: a role for IL-17 cytokines?

    OpenAIRE

    Puel, Anne; Picard, Capucine; Cypowyj, Sophie; Lilic, Desa; Abel, Laurent; Casanova, Jean-Laurent

    2010-01-01

    The various clinical manifestations of chronic mucocutaneous candidiasis (CMC) often result from acquired T-cell immunodeficiencies. More rarely, CMC results from inborn errors of immunity, the recent dissection of which has shed light on the molecular mechanisms of mucocutaneous immunity to Candida albicans. CMC may accompany various other infectious diseases in patients with almost any broad and profound T-cell primary immunodeficiency. By contrast, CMC is one of the few key infections in p...

  13. Contact inhibition of locomotion determines cell-cell and cell-substrate forces in tissues.

    Science.gov (United States)

    Zimmermann, Juliane; Camley, Brian A; Rappel, Wouter-Jan; Levine, Herbert

    2016-03-01

    Cells organized in tissues exert forces on their neighbors and their environment. Those cellular forces determine tissue homeostasis as well as reorganization during embryonic development and wound healing. To understand how cellular forces are generated and how they can influence the tissue state, we develop a particle-based simulation model for adhesive cell clusters and monolayers. Cells are contractile, exert forces on their substrate and on each other, and interact through contact inhibition of locomotion (CIL), meaning that cell-cell contacts suppress force transduction to the substrate and propulsion forces align away from neighbors. Our model captures the traction force patterns of small clusters of nonmotile cells and larger sheets of motile Madin-Darby canine kidney (MDCK) cells. In agreement with observations in a spreading MDCK colony, the cell density in the center increases as cells divide and the tissue grows. A feedback between cell density, CIL, and cell-cell adhesion gives rise to a linear relationship between cell density and intercellular tensile stress and forces the tissue into a nonmotile state characterized by a broad distribution of traction forces. Our model also captures the experimentally observed tissue flow around circular obstacles, and CIL accounts for traction forces at the edge. PMID:26903658

  14. Effect of Delta-9-tetrahydrocannabinol on mouse resistance to systemic Candida albicans infection.

    Directory of Open Access Journals (Sweden)

    Gideon W Blumstein

    Full Text Available Delta-9-tetrahydrocannabinol (Δ9-THC, the psychoactive component of marijuana, is known to suppress the immune responses to bacterial, viral and protozoan infections, but its effects on fungal infections have not been studied. Therefore, we investigated the effects of chronic Δ9-THC treatment on mouse resistance to systemic Candida albicans (C. albicans infection. To determine the outcome of chronic Δ9-THC treatment on primary, acute systemic candidiasis, c57BL/6 mice were given vehicle or Δ9-THC (16 mg/kg in vehicle on days 1-4, 8-11 and 15-18. On day 19, mice were infected with 5×10(5 C. albicans. We also determined the effect of chronic Δ9-THC (4-64 mg/kg treatment on mice infected with a non-lethal dose of 7.5×10(4 C. albicans on day 2, followed by a higher challenge with 5×10(5 C. albicans on day 19. Mouse resistance to the infection was assessed by survival and tissue fungal load. Serum cytokine levels were determine to evaluate the immune responses. In the acute infection, chronic Δ9-THC treatment had no effect on mouse survival or tissue fungal load when compared to vehicle treated mice. However, Δ9-THC significantly suppressed IL-12p70 and IL-12p40 as well as marginally suppressed IL-17 versus vehicle treated mice. In comparison, when mice were given a secondary yeast infection, Δ9-THC significantly decreased survival, increased tissue fungal burden and suppressed serum IFN-γ and IL-12p40 levels compared to vehicle treated mice. The data showed that chronic Δ9-THC treatment decreased the efficacy of the memory immune response to candida infection, which correlated with a decrease in IFN-γ that was only observed after the secondary candida challenge.

  15. 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. PMID:24623107

  16. Inhibiting the immunoproteasome exacerbates the pathogenesis of systemic Candida albicans infection in mice.

    Science.gov (United States)

    Mundt, Sarah; Basler, Michael; Buerger, Stefanie; Engler, Harald; Groettrup, Marcus

    2016-01-01

    Apart from its role in MHC class I antigen processing, the immunoproteasome has recently been implicated in the modulation of T helper cell differentiation under polarizing conditions in vitro and in the pathogenesis of autoimmune diseases in vivo. In this study, we investigated the influence of LMP7 on T helper cell differentiation in response to the fungus Candida albicans. We observed a strong effect of ONX 0914, an LMP7-selective inhibitor of the immunoproteasome, on IFN-γ and IL-17A production by murine splenocytes and human peripheral blood mononuclear cells (PBMCs) stimulated with C. albicans in vitro. Using a murine model of systemic candidiasis, we could confirm reduced generation of IFN-γ- and IL-17A-producing cells in ONX 0914 treated mice in vivo. Interestingly, ONX 0914 treatment resulted in increased susceptibility to systemic candidiasis, which manifested at very early stages of infection. Mice treated with ONX 0914 showed markedly increased kidney and brain fungal burden which resulted in enhanced neutrophil recruitment and immunopathology. Together, these results strongly suggest a role of the immunoproteasome in promoting proinflammatory T helper cells in response to C. albicans but also in affecting the innate antifungal immunity in a T helper cell-independent manner. PMID:26776888

  17. 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.

  18. Non-albicans Candida Infection: An Emerging Threat

    OpenAIRE

    Deorukhkar, Sachin C.; Santosh Saini; Stephen Mathew

    2014-01-01

    The very nature of infectious diseases has undergone profound changes in the past few decades. Fungi once considered as nonpathogenic or less virulent are now recognized as a primary cause of morbidity and mortality in immunocompromised and severely ill patients. Candida spp. are among the most common fungal pathogens. Candida albicans was the predominant cause of candidiasis. However, a shift toward non-albicans Candida species has been recently observed. These non-albicans Candida species d...

  19. Molecular genetic techniques for gene manipulation in Candida albicans

    OpenAIRE

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

    2014-01-01

    Candida albicans is one of the most common fungal pathogen in humans due to its high frequency as an opportunistic and pathogenic fungus causing superficial as well as invasive infections in immunocompromised patients. An understanding of gene function in C. albicans is necessary to study the molecular basis of its pathogenesis, virulence and drug resistance. Several manipulation techniques have been used for investigation of gene function in C. albicans, including gene disruption, controlled...

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

    OpenAIRE

    Koh, A.Y.; Kohler, J.R.; Coggshall, K.T.; Rooijen, van, N.; Pier, G B

    2008-01-01

    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 par...

  1. Zebrafish as a Model Host for Candida albicans Infection▿

    OpenAIRE

    Chao, Chun-Cheih; Hsu, Po-Chen; Jen, Chung-Feng; Chen, I-Hui; Wang, Chieh-Huei; Chan, Hau-Chien; Tsai, Pei-Wen; Tung, Kai-Che; Wang, Chian-Huei; Lan, Chung-Yu; Chuang, Yung-Jen

    2010-01-01

    In this work, the zebrafish model organism was developed to obtain a minivertebrate host system for a Candida albicans infection study. We demonstrated that C. albicans can colonize and invade zebrafish at multiple anatomical sites and kill the fish in a dose-dependent manner. Inside zebrafish, we monitored the progression of the C. albicans yeast-to-hypha transition by tracking morphogenesis, and we monitored the corresponding gene expression of the pathogen and the early host immune respons...

  2. Comparative study on the effects of two antifungal drugs against Candida albicans by microcalorimetry and transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Qing-Lian [Zhongnan Hospital, Wuhan University, Wuhan 430071 (China); Zhang, Juan [Zhongnan Hospital, Wuhan University, Wuhan 430071 (China); Department of Stomatology, Hubei Provincial Maternal and Child Health Hospital, Wuhan 430070 (China); Xu, Zi-Qiang; Li, Ran [State Key Laboratory of Virology and Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Jiang, Feng-Lei, E-mail: fljiang@whu.edu.cn [State Key Laboratory of Virology and Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Xiao, Qi, E-mail: qi.xiao@whu.edu.cn [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Liu, Yi [State Key Laboratory of Virology and Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2012-09-10

    Highlights: Black-Right-Pointing-Pointer Microcalorimetry is a fast, simple method to study the antibiotic property of drugs. Black-Right-Pointing-Pointer We noticed that the antibiotic effect of ITZ was slightly better than that of KTZ. Black-Right-Pointing-Pointer We perform the TEM to study the morphology changes of C. albicans cells. - Abstract: In this work, a multi-channel thermal activity monitor (TAM 2277) was applied to study the growth metabolism of Candida albicans (C. albicans) in vitro in the absence and presence of different concentrations of ketoconazole (KTZ) and itraconazole (ITZ). The results showed that the half inhibiting concentrations (IC{sub 50}) of C. albicans by KTZ and ITZ are 73.5 and 66.3 {mu}mol L{sup -1}, respectively. So the antibiotic effect of ITZ was slightly better than that of KTZ. The morphology of C. albicans cells both in the absence and presence of antifungal agents was examined by transmission electron microscopy (TEM). Our research also suggests that microcalorimetry is a fast, simple, non-invasive, non-destructive and more sensitive method, and can be easily performed to study the antibiotic property of different species of drugs on microorganism compared to other biological and clinical methods.

  3. Roles of Zinc-responsive transcription factor Csr1 in filamentous growth of the pathogenic Yeast Candida albicans.

    Science.gov (United States)

    Kim, Min-Jeong; Kil, Minkwang; Jung, Jong-Hwan; Kim, Jinmi

    2008-02-01

    In the fungal pathogen Candida albicans, the yeast-to-hyphal transition occurs in response to a broad range of environmental stimuli and is considered to be a major virulence factor. To address whether the zinc homeostasis affects the growth or pathogenicity of C. albicans, we functionally characterized the zinc-finger protein Csr1 during filamentation. The deduced amino acid sequence of Csr1 showed a 49% similarity to the zinc-specific transcription factor, Zap1 of Saccharomyces cerevisiae. Sequential disruptions of CSR1 were carried out in diploid C. albicans. The csr1/csr1 mutant strain showed severe growth defects under zinc-limited growth conditions and the filamentation defect under hyphainducing media. The colony morphology and the germ-tube formation were significantly affected by the csr1 mutation. The expression of the hyphae-specific gene HWP1 was also impaired in csr1/csr1 cells. The C. albicans homologs of ZRT1 and ZRT2, which are zinc-transporter genes in S. cerevisiae, were isolated. High-copy number plasmids of these genes suppressed the filamentation defect of the csr1/csr1 mutant strain. We propose that the filamentation phenotype of C. albicans is closely associated with the zinc homeostasis in the cells and that Csr1 plays a critical role in this regulation. PMID:18309267

  4. Comparative study on the effects of two antifungal drugs against Candida albicans by microcalorimetry and transmission electron microscopy

    International Nuclear Information System (INIS)

    Highlights: ► Microcalorimetry is a fast, simple method to study the antibiotic property of drugs. ► We noticed that the antibiotic effect of ITZ was slightly better than that of KTZ. ► We perform the TEM to study the morphology changes of C. albicans cells. - Abstract: In this work, a multi-channel thermal activity monitor (TAM 2277) was applied to study the growth metabolism of Candida albicans (C. albicans) in vitro in the absence and presence of different concentrations of ketoconazole (KTZ) and itraconazole (ITZ). The results showed that the half inhibiting concentrations (IC50) of C. albicans by KTZ and ITZ are 73.5 and 66.3 μmol L−1, respectively. So the antibiotic effect of ITZ was slightly better than that of KTZ. The morphology of C. albicans cells both in the absence and presence of antifungal agents was examined by transmission electron microscopy (TEM). Our research also suggests that microcalorimetry is a fast, simple, non-invasive, non-destructive and more sensitive method, and can be easily performed to study the antibiotic property of different species of drugs on microorganism compared to other biological and clinical methods.

  5. 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.

  6. Epidemiology of Candida infection. II. Application of biochemical methods for typing of Candida albicans strains.

    Science.gov (United States)

    Budak, A

    1990-01-01

    Biochemical profiles of 350 C. albicans isolates from five towns in Poland and from Freiburg in Germany were determined on the basis of nine biochemical tests of Odds and Abbott method. API 20 C AUX system and additionally a resistogram. The analysis of the strains according to Odds' and Abbotts's system showed that investigated strains can be typed into 9 profile codes of common biochemical patterns. There were some differences among the profiles according to their geographical origin and anatomical sources of the isolation. On the basis of the ability C. albicans strains to assimilate of carbon sources, 350 isolates were categorised into 13 separate auxotrophic profiles with the major one: 2,576,174 accounting for 81% of the total. The majority of the investigated isolates were susceptible to antifungal agents (83%). A disproportionate distribution of auxotrophic profiles limited the use of resistogram method and API 20 C AUX as systems for typing C. albicans strains. On the other hand, the method of Odds and Abbott provides valuable criteria for typing of C. albicans. PMID:2130802

  7. Using PCR to Compare the Expression of CDR1, CDR2, and MDR1 in Candida Albicans Isolates Resistant and Susceptible to Fluconazole

    Directory of Open Access Journals (Sweden)

    Nahid Ariana (MSc

    2015-10-01

    Full Text Available Background and objectives: More Candida albicans strains are reported resistant to fluconazole in patients with AIDS, cancer and organ recipients. Fluconazole resistance can be attributed to changes in pathways of sterol biosynthesis, mutation in or overexpression of ERG11 and the expression of CDR1, CDR2, and MDR1. This study aimed to compare the expression of CDR1, CDR2, and MDR1 in C. albicans resistant and susceptible to fluconazole. Methods: MIC testing for fluconazole was performed on C. albicans isolates isolated from patients with oral and vaginal candidiasis to determine resistant and susceptible strains. Then real time PCR was performed on the resistant and susceptible isolates and the expression of CDR1, CDR2, and MDR1 was compared in C. albicans. Results: Of 46 Candida albicans isolates, 20 susceptible isolates, 12 semi-susceptible isolates and 14 resistant isolates were identified by MIC. After real time PCR was performed, Candida albicans isolates susceptible to fluconazole showed moderate expression of CDR1, CDR2, and MDR1 genes, while resistant isolates showed slight or no expression. Conclusion: Increased expression of CDR1, CDR2, and MDR1 had less and insignificant role in resistance to fluconazole. Keywords: Candida Albicans, Gene Expression, Real time PCR method

  8. Mnn10 Maintains Pathogenicity in Candida albicans by Extending α-1,6-Mannose Backbone to Evade Host Dectin-1 Mediated Antifungal Immunity.

    Science.gov (United States)

    Zhang, Shi Qun; Zou, Zui; Shen, Hui; Shen, Shuai Shuai; Miao, Qi; Huang, Xin; Liu, Wei; Li, Li Ping; Chen, Si Min; Yan, Lan; Zhang, Jun Dong; Zhao, Jing Jun; Xu, Guo Tong; An, Mao Mao; Jiang, Yuan Ying

    2016-05-01

    The cell wall is a dynamic structure that is important for the pathogenicity of Candida albicans. Mannan, which is located in the outermost layer of the cell wall, has been shown to contribute to the pathogenesis of C. albicans, however, the molecular mechanism by which this occurs remains unclear. Here we identified a novel α-1,6-mannosyltransferase encoded by MNN10 in C. albicans. We found that Mnn10 is required for cell wall α-1,6-mannose backbone biosynthesis and polysaccharides organization. Deletion of MNN10 resulted in significant attenuation of the pathogenesis of C. albicans in a murine systemic candidiasis model. Inhibition of α-1,6-mannose backbone extension did not, however, impact the invasive ability of C. albicans in vitro. Notably, mnn10 mutant restored the invasive capacity in athymic nude mice, which further supports the notion of an enhanced host antifungal defense related to this backbone change. Mnn10 mutant induced enhanced Th1 and Th17 cell mediated antifungal immunity, and resulted in enhanced recruitment of neutrophils and monocytes for pathogen clearance in vivo. We also demonstrated that MNN10 could unmask the surface β-(1,3)-glucan, a crucial pathogen-associated molecular pattern (PAMP) of C. albicans recognized by host Dectin-1. Our results demonstrate that mnn10 mutant could stimulate an enhanced Dectin-1 dependent immune response of macrophages in vitro, including the activation of nuclear factor-κB, mitogen-activated protein kinase pathways, and secretion of specific cytokines such as TNF-α, IL-6, IL-1β and IL-12p40. In summary, our study indicated that α-1,6-mannose backbone is critical for the pathogenesis of C. albicans via shielding β-glucan from recognition by host Dectin-1 mediated immune recognition. Moreover, our work suggests that inhibition of α-1,6-mannose extension by Mnn10 may represent a novel modality to reduce the pathogenicity of C. albicans. PMID:27144456

  9. Modulation of phagosomal pH by Candida albicans promotes hyphal morphogenesis and requires Stp2p, a regulator of amino acid transport.

    OpenAIRE

    Slavena Vylkova; Lorenz, Michael C.

    2014-01-01

    Candida albicans, the most important fungal pathogen of humans, has a unique interaction with macrophages in which phagocytosis induces a switch from the yeast to hyphal form, allowing it to escape by rupturing the immune cell. While a variety of factors induce this switch in vitro, including neutral pH, it is not clear what triggers morphogenesis within the macrophage where the acidic environment should inhibit this transition. In vitro, C. albicans grown in similar conditions in which amino...

  10. Mnn10 Maintains Pathogenicity in Candida albicans by Extending α-1,6-Mannose Backbone to Evade Host Dectin-1 Mediated Antifungal Immunity.

    Directory of Open Access Journals (Sweden)

    Shi Qun Zhang

    2016-05-01

    Full Text Available The cell wall is a dynamic structure that is important for the pathogenicity of Candida albicans. Mannan, which is located in the outermost layer of the cell wall, has been shown to contribute to the pathogenesis of C. albicans, however, the molecular mechanism by which this occurs remains unclear. Here we identified a novel α-1,6-mannosyltransferase encoded by MNN10 in C. albicans. We found that Mnn10 is required for cell wall α-1,6-mannose backbone biosynthesis and polysaccharides organization. Deletion of MNN10 resulted in significant attenuation of the pathogenesis of C. albicans in a murine systemic candidiasis model. Inhibition of α-1,6-mannose backbone extension did not, however, impact the invasive ability of C. albicans in vitro. Notably, mnn10 mutant restored the invasive capacity in athymic nude mice, which further supports the notion of an enhanced host antifungal defense related to this backbone change. Mnn10 mutant induced enhanced Th1 and Th17 cell mediated antifungal immunity, and resulted in enhanced recruitment of neutrophils and monocytes for pathogen clearance in vivo. We also demonstrated that MNN10 could unmask the surface β-(1,3-glucan, a crucial pathogen-associated molecular pattern (PAMP of C. albicans recognized by host Dectin-1. Our results demonstrate that mnn10 mutant could stimulate an enhanced Dectin-1 dependent immune response of macrophages in vitro, including the activation of nuclear factor-κB, mitogen-activated protein kinase pathways, and secretion of specific cytokines such as TNF-α, IL-6, IL-1β and IL-12p40. In summary, our study indicated that α-1,6-mannose backbone is critical for the pathogenesis of C. albicans via shielding β-glucan from recognition by host Dectin-1 mediated immune recognition. Moreover, our work suggests that inhibition of α-1,6-mannose extension by Mnn10 may represent a novel modality to reduce the pathogenicity of C. albicans.

  11. Mnn10 Maintains Pathogenicity in Candida albicans by Extending α-1,6-Mannose Backbone to Evade Host Dectin-1 Mediated Antifungal Immunity

    Science.gov (United States)

    Zhang, Shi Qun; Zou, Zui; Shen, Hui; Shen, Shuai Shuai; Miao, Qi; Huang, Xin; Liu, Wei; Li, Li Ping; Chen, Si Min; Yan, Lan; Zhang, Jun Dong; Zhao, Jing Jun; Xu, Guo Tong; An, Mao Mao; Jiang, Yuan Ying

    2016-01-01

    The cell wall is a dynamic structure that is important for the pathogenicity of Candida albicans. Mannan, which is located in the outermost layer of the cell wall, has been shown to contribute to the pathogenesis of C. albicans, however, the molecular mechanism by which this occurs remains unclear. Here we identified a novel α-1,6-mannosyltransferase encoded by MNN10 in C. albicans. We found that Mnn10 is required for cell wall α-1,6-mannose backbone biosynthesis and polysaccharides organization. Deletion of MNN10 resulted in significant attenuation of the pathogenesis of C. albicans in a murine systemic candidiasis model. Inhibition of α-1,6-mannose backbone extension did not, however, impact the invasive ability of C. albicans in vitro. Notably, mnn10 mutant restored the invasive capacity in athymic nude mice, which further supports the notion of an enhanced host antifungal defense related to this backbone change. Mnn10 mutant induced enhanced Th1 and Th17 cell mediated antifungal immunity, and resulted in enhanced recruitment of neutrophils and monocytes for pathogen clearance in vivo. We also demonstrated that MNN10 could unmask the surface β-(1,3)-glucan, a crucial pathogen-associated molecular pattern (PAMP) of C. albicans recognized by host Dectin-1. Our results demonstrate that mnn10 mutant could stimulate an enhanced Dectin-1 dependent immune response of macrophages in vitro, including the activation of nuclear factor-κB, mitogen-activated protein kinase pathways, and secretion of specific cytokines such as TNF-α, IL-6, IL-1β and IL-12p40. In summary, our study indicated that α-1,6-mannose backbone is critical for the pathogenesis of C. albicans via shielding β-glucan from recognition by host Dectin-1 mediated immune recognition. Moreover, our work suggests that inhibition of α-1,6-mannose extension by Mnn10 may represent a novel modality to reduce the pathogenicity of C. albicans. PMID:27144456

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

    OpenAIRE

    Voon-Kin Chin; Kuan-Jeang Foong; Abdullah Maha; Basir Rusliza; Mohtarrudin Norhafizah; Pei Pei Chong

    2014-01-01

    Different murine species differ in their susceptibility to systemic infection with Candida albicans, giving rise to varied host immune responses, and this is compounded by variations in virulence of the different yeast strains used. Hence, this study was aimed at elucidating the pathogenesis of a clinical C. albicans isolate (HVS6360) in a murine intravenous challenge model by examining the different parameters which included the counts of red blood cells and associated components as well as ...

  13. Crystal Violet Assay for Determining Viability of Cultured Cells.

    Science.gov (United States)

    Feoktistova, Maria; Geserick, Peter; Leverkus, Martin

    2016-01-01

    Adherent cells detach from cell culture plates during cell death. This characteristic can be used for the indirect quantification of cell death and to determine differences in proliferation upon stimulation with death-inducing agents. One simple method to detect maintained adherence of cells is the staining of attached cells with crystal violet dye, which binds to proteins and DNA. Cells that undergo cell death lose their adherence and are subsequently lost from the population of cells, reducing the amount of crystal violet staining in a culture. This protocol describes a quick and reliable screening method that is suitable for the examination of the impact of chemotherapeutics or other compounds on cell survival and growth inhibition. However, characterization of the cause of reduced crystal violet staining requires additional methods detailed elsewhere. PMID:27037069

  14. Antimicrobial efficacy of the EndoVac system plus PDT against intracanal Candida albicans: an ex vivo study

    Directory of Open Access Journals (Sweden)

    Rachel Garcia de MIRANDA

    2015-01-01

    Full Text Available This study evaluated the ex vivoantimicrobial efficacy of the EndoVac system and the photodynamic therapy (PDT associated with chemomechanical debridement (CMD and intracanal medication on Candida albicans. Seventy-eight sterile premolars were contaminated withC. albicans (ATCC 21433 for 30 days. The teeth were randomly assigned into four groups: Control (CMD with conventional irrigation; Endovac (CMD with EndoVac system; PDT (CMD with conventional irrigation and PDT; and Endovac + PDT (CMD with EndoVac and PDT. After the therapies, intracanal dressing (calcium hydroxide was applied to all teeth for seven days. Samples were obtained before (T1 and after the therapeutic procedures (T2, and after intracanal medication (T3, plated onto BHI agar and incubated (37°C, 48 h to determine the colony-forming units (CFU/mL. The overall mean level ofC. albicans at baseline was relatively high (1.85 x 106 ± 2.7 x 106 CFU mL-1. A significant reduction of C. albicans(p < 0.05 was observed over time (T1 to T2 and T1 to T3 in all groups. An additional significant reduction from T2 to T3 was observed only in the Endovac group (p < 0.05. No differences in mean reduction of C. albicans were observed among groups. However, the Endovac group presented the lowest mean counts of C. albicans at T3, whereas the PDT group had the highest counts of this microorganism (p < 0.05. The EndoVac system of irrigation/aspiration associated with CMD was the most effective therapeutic protocol for reducing intracanal levels of C. albicans. PDT showed a very limited efficacy against this species.

  15. Technetium-99m labelled fluconazole and antimicrobial peptides for imaging of Candida albicans and Aspergillus fumigatus infections

    International Nuclear Information System (INIS)

    The aim of this study was to investigate whether technetium-99m labelled fluconazole can distinguish fungal from bacterial infections. Fluconazole was labelled with 99mTc and radiochemical analysis showed less than 5% impurities. The labelling solution was injected into animals with experimental infections. For comparison, we used two peptides for infection detection, i.e. UBI 29-41 and hLF 1-11, and human IgG, all labelled with 99mTc. Mice were infected with Candida albicans or injected with heat-killed C. albicans or lipopolysaccharides to induce sterile inflammation. Also, mice were infected with Staphylococcus aureus or Klebsiella pneumoniae. Next, accumulation of 99mTc-fluconazole and 99mTc-labelled peptides/IgG at affected sites was determined scintigraphically. 99mTc-fluconazole detected C. albicans infections (T/NT ratio=3.6±0.47) without visualising bacterial infections (T/NT ratio=1.3±0.04) or sterile inflammatory processes (heat-killed C. albicans: T/NT ratio=1.3±0.2; lipopolysaccharide: T/NT ratio=1.4±0.1). C. albicans infections were already seen within the first hour after injection of 99mTc-fluconazole (T/NT ratio=3.1±0.2). A good correlation (R2=0.864; P99mTc-UBI 29-41 and 99mTc-hLF 1-11 were able to distinguish C. albicans infections from sterile inflammatory processes in mice, these 99mTc-labelled peptides did not distinguish these fungal infections from bacterial infections. It is concluded that 99mTc-fluconazole distinguishes infections with C. albicans from bacterial infections and sterile inflammations. (orig.)

  16. A Study on Specific IgE Against Candida Albicans in Atopic Dermatitis Patients Referred to Boali Hospital, Sari- Iran

    Directory of Open Access Journals (Sweden)

    R.A. Mohammadpour, Ph.D.

    2007-01-01

    Full Text Available AbstractBackground and purpose: Candida albicans (C. albicans as a micro flora of the human could be responsible for a continuous release of allergen and may be responsible for chronic atopic dermatitis (AD in sensitive patients. Thus, in this study, we analyzed AD patients for total IgE and specific IgE, against C. albicans.Materials and Methods: A total of 120 AD patients (male 52 and female 68 were introduced in this study. The age range varied from 4 months to 60 years (mean about 12.9 years. Serum total IgE was assayed by ELISA kit (RADIM. Solid phase was captured by sandwich ELISA assay, using a micro well format for the determination of serum specific IgE to C. Albicans was used according to the manufacturer’s instructions, (ALerCHEK Allergen specific human IgE.Results: Of the 120 AD patients, 37 subjects (30.8% had total IgE higher than 100 IU/mL, 44 subjects (63.7 % 20-100IU/mL and 39 subjects (32.5% less than 20 IU/mL. 9 (7.5% of the patients had specific IgE against C. albicans. Among the patients who were positive for specific IgE to C. albicans, 6 (66.7% were women.Conclusion: The result of our study on serum total IgE in AD patients is concordant with other studies from different countries. In comparison to other studies, our AD patients showed less frequency of specific IgE against Candida albicans. The explanations for the variation in the results obtained in various studies could be due to the age of patients, severity of disease, difference in the antigen preparation, different methods for IgE analysis and total IgE level.

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

    Science.gov (United States)

    Verma-Gaur, Jiyoti; Qu, Yue; Harrison, Paul F; Lo, Tricia L; Quenault, Tara; Dagley, Michael J; Bellousoff, Matthew; Powell, David R; Beilharz, Traude H; Traven, Ana

    2015-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Jiyoti Verma-Gaur

    2015-10-01

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

  19. Selected mechanisms of molecular resistance of Candida albicans to azole drugs.

    Science.gov (United States)

    Gołąbek, Karolina; Strzelczyk, Joanna Katarzyna; Owczarek, Aleksander; Cuber, Piotr; Ślemp-Migiel, Anna; Wiczkowski, Andrzej

    2015-01-01

    A phenomenon of increasing resistance of Candida spp. to azoles has been observed for several years now. One of the mechanisms of lack of sensitivity to azoles is associated with CDR1, CDR2, MRD1 genes (their products are active transport pumps conditioning drug efflux from pathogen's cell), and ERG11 gene (encoding lanosterol 14α-demethylase). Test material was 120 strains of Candida albicans (60 resistant and 60 susceptible to azole drugs) obtained from clinical samples. The first stage of experiment assessed the expression of CDR1, CDR2, MDR1 and ERG11 genes by Q-PCR. The impact of ERG11 gene's mutations on the expression of this gene was analysed. The final stage of the experiment assessed the level of genome methylation of Candida albicans strains. An increase in the expression of CDR2, MDR1 and ERG11 was observed in azole-resistant strains of Candida albicans in comparison to strains sensitive to this class of drugs. Furthermore, 19 changes in the sequence of ERG11 were detected in tested strains. Four of the discovered mutations: T495A, A530C, G622A and A945C led to the following amino acid substitutions: D116E, K128T, V159I and E266D, respectively. It has also been found that statistically five mutations: T462C, G1309A, C216T, C1257T and A945C affected the expression of ERG11. The applied method of assessing the level of methylation of Candida albicans genome did not confirm its role in the development of resistance to azoles. The results indicate however, that resistance of Candida albicans strains to azole drugs is multifactorial. PMID:25901298

  20. Antifungal Activity of Salvia miltiorrhiza Against Candida albicans Is Associated with the Alteration of Membrane Permeability and (1,3)-β-D-Glucan Synthase Activity.

    Science.gov (United States)

    Lee, Heung-Shick; Kim, Younhee

    2016-03-28

    Candidiasis has posed a serious health risk to immunocompromised patients owing to the increase in resistant yeasts, and Candida albicans is the prominent pathogen of fungal infections. Therefore, there is a critical need for the discovery and characterization of novel antifungals to treat infections caused by C. albicans. In the present study, we report on the antifungal activity of the ethanol extract from Salvia miltiorrhiza against C. albicans and the possible mode of action against C. albicans. The increase in the membrane permeability was evidenced by changes in diphenylhexatriene binding and release of both 260-nm-absorbing intracellular materials and protein. In addition, inhibition of cell wall synthesis was demonstrated by the enhanced minimal inhibitory concentration in the presence of sorbitol and reduced (1,3)-β-D-glucan synthase activity. The above evidence supports the notion that S. miltiorrhiza has antifungal activity against C. albicans by the synergistic activity of targeting the cell membrane and cell wall. These findings indicate that S. miltiorrhiza displays effective activity against C. albicans in vitro and merits further investigation to treat C. albicansassociated infections. PMID:26699747

  1. Aft2, a novel transcription regulator, is required for iron metabolism, oxidative stress, surface adhesion and hyphal development in Candida albicans.

    Science.gov (United States)

    Xu, Ning; Cheng, Xinxin; Yu, Qilin; Qian, Kefan; Ding, Xiaohui; Liu, Ruming; Zhang, Biao; Xing, Laijun; Li, Mingchun

    2013-01-01

    Morphological transition and iron metabolism are closely relevant to Candida albicans pathogenicity and virulence. In our previous study, we demonstrated that C. albicans Aft2 plays an important role in ferric reductase activity and virulence. Here, we further explored the roles of C. albicans Aft2 in numerous cellular processes. We found that C. albicans Aft2 exhibited an important role in iron metabolism through bi-directional regulation effects on iron-regulon expression. Deletion of AFT2 reduced cellular iron accumulation under iron-deficient conditions. Furthermore, both reactive oxygen species (ROS) generation and superoxide dismutase (SOD) activity were remarkably increased in the aft2Δ/Δ mutant, which were thought to be responsible for the defective responses to oxidative stress. However, we found that over-expression of C. albicans AFT2 under the regulation of the strong PGK1 promoter could not effectively rescue Saccharomyces cerevisiae aft1Δ mutant defects in some cellular processes, such as cell-wall assembly, ion homeostasis and alkaline resistance, suggesting a possibility that C. albicans Aft2 weakened its functional role of regulating some cellular metabolism during the evolutionary process. Interestingly, deletion of AFT2 in C. albicans increased cell surface hydrophobicity, cell flocculation and the ability of adhesion to polystyrene surfaces. In addition, our results also revealed that C. albicans Aft2 played a dual role in regulating hypha-specific genes under solid and liquid hyphal inducing conditions. Deletion of AFT2 caused an impaired invasive growth in solid medium, but an increased filamentous aggregation and growth in liquid conditions. Moreover, iron deficiency and environmental cues induced nuclear import of Aft2, providing additional evidence for the roles of Aft2 in transcriptional regulation. PMID:23626810

  2. Environmental pH adaption and morphological transitions in Candida albicans.

    Science.gov (United States)

    Du, Han; Huang, Guanghua

    2016-05-01

    The human fungal pathogen Candida albicans encounters a wide range of pH stresses during its commensal and pathogenic lifestyles. It has been well studied that environmental pH regulates the yeast-filamentous growth transition in this fungus. White-opaque switching is another type of phenotypic transitions in C. albicans. White and opaque cells are two morphologically and functionally distinct cell types, which differ in many aspects including global gene expression profiles, virulence, mating competency, and susceptibility to antifungals. The switch between white and opaque cell types is heritable and epigenetically regulated. In a recently study, Sun et al. (Eukaryot Cell 14:1127-1134, 2015) reported that pH plays a critical role in the regulation of the white-opaque phenotypic switch and sexual mating in C. albicans via both the conserved Rim101-mediated pH sensing and cAMP signaling pathways. The effect of pH on the two biological processes may represent a balancing act between host environmental adaptation and sexual reproduction in this pathogenic fungus. PMID:26581628

  3. Hsp90 is involved in apoptosis of Candida albicans by regulating the calcineurin-caspase apoptotic pathway.

    Science.gov (United States)

    Dai, BaoDi; Wang, Yan; Li, DeDong; Xu, Yi; Liang, RongMei; Zhao, LanXue; Cao, YongBing; Jia, JianHui; Jiang, YuanYing

    2012-01-01

    Candida albicans is the most common human fungal pathogen. Recent evidence has revealed the occurrence of apoptosis in C. albicans that is inducible by environmental stresses such as hydrogen peroxide, acetic acid, and amphotericin B. Apoptosis is regulated by the calcineurin-caspase pathway in C. albicans, and calcineurin is under the control of Hsp90 in echinocandin resistance. However, the role of Hsp90 in apoptosis of C. albicans remains unclear. In this study, we investigated the role of Hsp90 in apoptosis of C. albicans by using an Hsp90-compromised strain tetO-HSP90/hsp90 and found that upon apoptotic stimuli, including hydrogen peroxide, acetic acid or amphotericin B treatment, less apoptosis occurred, less ROS was produced, and more cells survived in the Hsp90-compromised strain compared with the Hsp90/Hsp90 wild-type strain. In addition, Hsp90-compromised cells were defective in up-regulating caspase-encoding gene CaMCA1 expression and activating caspase activity upon the apoptotic stimuli. Investigations on the relationship between Hsp90 and calcineurin revealed that activation of calcineurin could up-regulate apoptosis but could not further down-regulate apoptosis in Hsp90-compromised cells, indicating that calcineurin was downstream of Hsp90. Hsp90 inhibitor geldanamycin (GdA) could further decrease the apoptosis in calcineurin-pathway-defect strains, indicating that compromising Hsp90 function had a stronger effect than compromising calcineurin function on apoptosis. Collectively, this study demonstrated that compromised Hsp90 reduced apoptosis in C. albicans, partially through downregulating the calcineurin-caspase pathway. PMID:23028789

  4. Hsp90 is involved in apoptosis of Candida albicans by regulating the calcineurin-caspase apoptotic pathway.

    Directory of Open Access Journals (Sweden)

    BaoDi Dai

    Full Text Available Candida albicans is the most common human fungal pathogen. Recent evidence has revealed the occurrence of apoptosis in C. albicans that is inducible by environmental stresses such as hydrogen peroxide, acetic acid, and amphotericin B. Apoptosis is regulated by the calcineurin-caspase pathway in C. albicans, and calcineurin is under the control of Hsp90 in echinocandin resistance. However, the role of Hsp90 in apoptosis of C. albicans remains unclear. In this study, we investigated the role of Hsp90 in apoptosis of C. albicans by using an Hsp90-compromised strain tetO-HSP90/hsp90 and found that upon apoptotic stimuli, including hydrogen peroxide, acetic acid or amphotericin B treatment, less apoptosis occurred, less ROS was produced, and more cells survived in the Hsp90-compromised strain compared with the Hsp90/Hsp90 wild-type strain. In addition, Hsp90-compromised cells were defective in up-regulating caspase-encoding gene CaMCA1 expression and activating caspase activity upon the apoptotic stimuli. Investigations on the relationship between Hsp90 and calcineurin revealed that activation of calcineurin could up-regulate apoptosis but could not further down-regulate apoptosis in Hsp90-compromised cells, indicating that calcineurin was downstream of Hsp90. Hsp90 inhibitor geldanamycin (GdA could further decrease the apoptosis in calcineurin-pathway-defect strains, indicating that compromising Hsp90 function had a stronger effect than compromising calcineurin function on apoptosis. Collectively, this study demonstrated that compromised Hsp90 reduced apoptosis in C. albicans, partially through downregulating the calcineurin-caspase pathway.

  5. Sensitization of Candida albicans biofilms to various antifungal drugs by cyclosporine A

    Directory of Open Access Journals (Sweden)

    Shinde Ravikumar B

    2012-10-01

    Full Text Available Abstract Background Biofilms formed by Candida albicans are resistant towards most of the available antifungal drugs. Therefore, infections associated with Candida biofilms are considered as a threat to immunocompromised patients. Combinatorial drug therapy may be a good strategy to combat C. albicans biofilms. Methods Combinations of five antifungal drugs- fluconazole (FLC, voriconazole (VOR, caspofungin (CSP, amphotericin B (AmB and nystatin (NYT with cyclosporine A (CSA were tested in vitro against planktonic and biofilm growth of C. albicans. Standard broth micro dilution method was used to study planktonic growth, while biofilms were studied in an in vitro biofilm model. A chequerboard format was used to determine fractional inhibitory concentration indices (FICI of combination effects. Biofilm growth was analyzed using XTT-metabolic assay. Results MICs of various antifungal drugs for planktonic growth of C. albicans were lowered in combination with CSA by 2 to 16 fold. Activity against biofilm development with FIC indices of 0.26, 0.28, 0.31 and 0.25 indicated synergistic interactions between FLC-CSA, VOR-CSA, CSP-CSA and AmB-CSA, respectively. Increase in efficacy of the drugs FLC, VOR and CSP against mature biofilms after addition of 62.5 μg/ml of CSA was evident with FIC indices 0.06, 0.14 and 0.37, respectively. Conclusions The combinations with CSA resulted in increased susceptibility of biofilms to antifungal drugs. Combination of antifungal drugs with CSA would be an effective prophylactic and therapeutic strategy against biofilm associated C. albicans infections.

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

    Science.gov (United States)

    Min, Kyunghun; Ichikawa, Yuichi

    2016-01-01

    ABSTRACT Clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated gene 9 (CRISPR-Cas9) systems are used for a wide array of genome-editing applications in organisms ranging from fungi to plants and animals. Recently, a CRISPR-Cas9 system has been developed for the diploid fungal pathogen Candida albicans; the system accelerates genetic manipulation dramatically [V. K. Vyas, M. I. Barrasa, and G. R. Fink, Sci Adv 1(3):e1500248, 2015, http://dx.doi.org/10.1126/sciadv.1500248]. We show here that the CRISPR-Cas9 genetic elements can function transiently, without stable integration into the genome, to enable the introduction of a gene deletion construct. We describe a transient CRISPR-Cas9 system for efficient gene deletion in C. albicans. Our observations suggest that there are two mechanisms that lead to homozygous deletions: (i) independent recombination of transforming DNA into each allele and (ii) recombination of transforming DNA into one allele, followed by gene conversion of the second allele. Our approach will streamline gene function analysis in C. albicans, and our results indicate that DNA can function transiently after transformation of this organism. IMPORTANCE The fungus Candida albicans is a major pathogen. Genetic analysis of this organism has revealed determinants of pathogenicity, drug resistance, and other unique biological features, as well as the identities of prospective drug targets. The creation of targeted mutations has been greatly accelerated recently through the implementation of CRISPR genome-editing technology by Vyas et al. [Sci Adv 1(3):e1500248, 2015, http://dx.doi.org/10.1126/sciadv.1500248]. In this study, we find that CRISPR elements can be expressed from genes that are present only transiently, and we develop a transient CRISPR system that further accelerates C. albicans genetic manipulation. PMID:27340698

  7. Garcinia xanthochymus Benzophenones Promote Hyphal Apoptosis and Potentiate Activity of Fluconazole against Candida albicans Biofilms

    OpenAIRE

    Jackson, Desmond N.; Yang, Lin; Wu, ShiBiao; Kennelly, Edward J.; Lipke, Peter N.

    2015-01-01

    Xanthochymol and garcinol, isoprenylated benzophenones purified from Garcinia xanthochymus fruits, showed multiple activities against Candida albicans biofilms. Both compounds effectively prevented emergence of fungal germ tubes and were also cytostatic, with MICs of 1 to 3 μM. The compounds therefore inhibited development of hyphae and subsequent biofilm maturation. Xanthochymol treatment of developing and mature biofilms induced cell death. In early biofilm development, killing had the char...

  8. In vitro antifungal activity of baicalin against Candida albicans biofilms via apoptotic induction.

    Science.gov (United States)

    Wang, TianMing; Shi, GaoXiang; Shao, Jing; Wu, DaQiang; Yan, YuanYuan; Zhang, MengXiang; Cui, YanYan; Wang, ChangZhong

    2015-10-01

    The aim of this study was to investigate the antifungal activity of baicalin and its potential mechanism of action against Candida albicans biofilms. The standard techniques including microdilution method and checkerboard assay were employed to evaluate the susceptibilities of baicalin alone and in combination with fluconazole against planktonic and biofilm cells of C. albicans. Transmission electron microscope (TEM), scanning electron microscope (SEM), fluorescent microscope and flow cytometry were used to assess the apoptotic incidences induced by baicalin in biofilm cells. The expressions of four genes (RAS1, CAP1, PDE2 and TPK1) related to Ras-cAMP-PKA pathway were also analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The results showed that minimum inhibitory concentration (MIC) and sessile minimum inhibitory concentration (SMIC50) of baicalin were 500 and 2000 μg/mL with fractional inhibitory concentration indexs (FICIs) ranging from 0.28 to 0.75. A series of events related to apoptosis were observed in baicalin-treated C. albicans biofilms, including extensive chromatin condensation along the nuclear envelope, ROS accumulation, MMP reduction, PS externalization, nuclear fragmentation, chromatin condensation, metacaspase activation and Cyt C release. Additionally, the expressions of RAS1 and TPK1 were up-regulated by 3.2 and 2.9 folds respectively, while those of CAP1 and PDE2 were down-regulated by 3.3 and 6.6 folds respectively after exposure to baicalin in biofilm cells. In conclusion, baicalin can suppress the development of C. albicans biofilms most likely due to inducing cell death via apoptosis. PMID:26169236

  9. Role of CaGap permeases in the virulence and pathogenicity of Candida albicans

    Czech Academy of Sciences Publication Activity Database

    Kraidlová, Lucie; Van Dijck, P.; Sychrová, Hana

    Praha, 2007. s. 10-10. [Molecular Mechanisms of Cell Interactions. 29.10.2007-30.10.2007, Praha] R&D Projects: GA MŠk(CZ) LC531; GA ČR(CZ) GD204/03/H066 Institutional research plan: CEZ:AV0Z50110509 Keywords : spr2 * CaGAP * fusion PCR * C. albicans Subject RIV: EB - Genetics ; Molecular Biology

  10. The role of phenotypic switching in the basic biology and pathogenesis of Candida albicans

    OpenAIRE

    Soll, David R.

    2014-01-01

    The ‘‘white-opaque’’ transition in Candida albicans was discovered in 1987. For the next fifteen years, a significant body of knowledge accumulated that included differences between the cell types in gene expression, cellular architecture and virulence in cutaneous and systemic mouse models. However, it was not until 2002 that we began to understand the role of switching in the life history of this pathogen, the role of the mating type locus and the molecular pathways that regulated it. Then ...

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

    OpenAIRE

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

    1998-01-01

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

  12. Development and Validation of an In Vivo Candida albicans Biofilm Denture Model▿

    OpenAIRE

    Nett, Jeniel E.; Marchillo, Karen; Spiegel, Carol A.; Andes, David R.

    2010-01-01

    The most common form of oral candidiasis, denture-associated stomatitis, involves biofilm growth on an oral prosthetic surface. Cells in this unique environment are equipped to withstand host defenses and survive antifungal therapy. Studies of the biofilm process on dentures have primarily been limited to in vitro models. We developed a rodent acrylic denture model and characterized the Candida albicans and mixed oral bacterial flora biofilm formation, architecture, and drug resistance in viv...

  13. Candida albicans osteomyelitis of the cervical spine

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jang-Gyu; Hong, Hyun-Sook [Soonchunhyang University Bucheon Hospital, Department of Radiology, Bucheon-Si, Gyeonggi-Do (Korea); Koh, Yoon-Woo [Soonchunhyang University Bucheon Hospital, Department of Otolaryngology - Head and Neck Surgery, Bucheon-Si, Gyeonggi-Do (Korea); Kim, Hee-Kyung [Soonchunhyang University Bucheon Hospital, Department of Pathology, Bucheon-Si, Gyeonggi-Do (Korea); Park, Jung-Mi [Soonchunhyang University Bucheon Hospital, Department of Nuclear Medicine, Bucheon-Si, Gyeonggi-Do (Korea)

    2008-04-15

    Fungal osteomyelitis is a rare infection that usually develops in immunocompromised patients. Additionally, involvement of the cervical spine by Candida albicans is extremely rare; only three previous cases of Candida vertebral osteomyelitis have been reported in the literature. The diagnosis may be delayed due to nonspecific radiologic findings and a slow progression. We report the CT, MRI, bone scan, and PET-CT findings in a patient who developed Candida osteomyelitis, which was initially misdiagnosed as metastasis, at the atlas and axis following treatment for nasopharyngeal cancer. (orig.)

  14. Candida albicans osteomyelitis of the cervical spine

    International Nuclear Information System (INIS)

    Fungal osteomyelitis is a rare infection that usually develops in immunocompromised patients. Additionally, involvement of the cervical spine by Candida albicans is extremely rare; only three previous cases of Candida vertebral osteomyelitis have been reported in the literature. The diagnosis may be delayed due to nonspecific radiologic findings and a slow progression. We report the CT, MRI, bone scan, and PET-CT findings in a patient who developed Candida osteomyelitis, which was initially misdiagnosed as metastasis, at the atlas and axis following treatment for nasopharyngeal cancer. (orig.)

  15. Melittin induces apoptotic features in Candida albicans

    International Nuclear Information System (INIS)

    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.

  16. 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.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    SH Mirhendi

    2003-07-01

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

  19. Cell for determination of tritium concentration by liquid radiometer

    International Nuclear Information System (INIS)

    An optimized cell is described for determination of tritium concentration in the form of tritiated water by a liquid scintillation radiometer at a level of 104 Bq/m3. The cell is made of Teflon and has a wall thickness of 0.8-1.0 mm. The useful capacity of the cell is 45 cm3 (5 cm3 of tritiated water and 40 cm3 of ZhS-81 liquid scintillator)

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

    Directory of Open Access Journals (Sweden)

    Mark Feldman

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

  1. Nanofiber density determines endothelial cell behavior on hydrogel matrix

    International Nuclear Information System (INIS)

    When cultured under static conditions, bacterial cellulose pellicles, by the nature of the polymer synthesis that involves molecular oxygen, are characterized by two distinct surface sides. The upper surface is denser in fibers (entangled) than the lower surface that shows greater surface porosity. Human umbilical vein endothelial cells (HUVECs) were used to exploit how the microarchitecture (i.e., surface porosity, fiber network structure, surface topology, and fiber density) of bacterial cellulose pellicle surfaces influence cell–biomaterial interaction and therefore cell behavior. Adhesion, cell ingrowth, proliferation, viability and cell death mechanisms were evaluated on the two pellicle surface sides. Cell behavior, including secondary necrosis, is influenced only by the microarchitecture of the surface, since the biomaterial is extremely pure (constituted of cellulose and water only). Cell–cellulose fiber interaction is the determinant signal in the cell–biomaterial responses, isolated from other frequently present interferences such as protein and other chemical traces usually present in cell culture matrices. Our results suggest that microarchitecture of hydrogel materials might determine the performance of biomedical products, such as bacterial cellulose tissue engineering constructs (BCTECs). - Highlights: • Topography of BC pellicle is relevant to determine endothelial cells' fate. • Cell–biomaterial response is affected by the topography of BC-pellicle surface. • Endothelial cells exhibit different behavior depending on the BC topography. • Apoptosis and necrosis of endothelial cells were affected by the BC topography

  2. Antigen Processing by Autoreactive B Cells Promotes Determinant Spreading

    Institute of Scientific and Technical Information of China (English)

    Yang D.Dai; George Carayanniotis; Eli Sercarz

    2005-01-01

    Acute primary immune responses tend to focus on few immunodominant determinants using a very limited number of T cell clones for expansion, whereas chronic inflammatory responses generally recruit a large number of different T cell clones to attack a broader range of determinants of the invading pathogens or the inflamed tissues.In T cell-mediated organ-specific autoimmune disease, a transition from the acute to the chronic phase contributes to pathogenesis, and the broadening process is called determinant spreading. The cellular components catalyzing the spreading reaction are not identified. It has been suggested that autoreactive B cells may play a central role in diversifying autoreactive T cell responses, possibly through affecting antigen processing and presentation. The clonal identity and diversity of the B cells and antibodies seem critical in regulating T cell activity and subsequent tissue damage or repair. Here, we use two autoimmune animal models, experimental autoimmune thyroiditis (EAT)and type 1 diabetes (T1D), to discuss how autoreactive B cells or antibodies alter the processing and presentation of autoantigens to regulate specific T cell response.

  3. Nanofiber density determines endothelial cell behavior on hydrogel matrix

    Energy Technology Data Exchange (ETDEWEB)

    Berti, Fernanda V., E-mail: fernanda@intelab.ufsc.br [Department of Chemical and Food Engineering, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Rambo, Carlos R. [Department of Electrical Engineering, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Dias, Paulo F. [Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Porto, Luismar M. [Department of Chemical and Food Engineering, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil)

    2013-12-01

    When cultured under static conditions, bacterial cellulose pellicles, by the nature of the polymer synthesis that involves molecular oxygen, are characterized by two distinct surface sides. The upper surface is denser in fibers (entangled) than the lower surface that shows greater surface porosity. Human umbilical vein endothelial cells (HUVECs) were used to exploit how the microarchitecture (i.e., surface porosity, fiber network structure, surface topology, and fiber density) of bacterial cellulose pellicle surfaces influence cell–biomaterial interaction and therefore cell behavior. Adhesion, cell ingrowth, proliferation, viability and cell death mechanisms were evaluated on the two pellicle surface sides. Cell behavior, including secondary necrosis, is influenced only by the microarchitecture of the surface, since the biomaterial is extremely pure (constituted of cellulose and water only). Cell–cellulose fiber interaction is the determinant signal in the cell–biomaterial responses, isolated from other frequently present interferences such as protein and other chemical traces usually present in cell culture matrices. Our results suggest that microarchitecture of hydrogel materials might determine the performance of biomedical products, such as bacterial cellulose tissue engineering constructs (BCTECs). - Highlights: • Topography of BC pellicle is relevant to determine endothelial cells' fate. • Cell–biomaterial response is affected by the topography of BC-pellicle surface. • Endothelial cells exhibit different behavior depending on the BC topography. • Apoptosis and necrosis of endothelial cells were affected by the BC topography.

  4. 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.

  5. The Monoterpene Carvacrol Generates Endoplasmic Reticulum Stress in the Pathogenic Fungus Candida albicans.

    Science.gov (United States)

    Chaillot, Julien; Tebbji, Faiza; Remmal, Adnane; Boone, Charlie; Brown, Grant W; Bellaoui, Mohammed; Sellam, Adnane

    2015-08-01

    The monoterpene carvacrol, the major component of oregano and thyme oils, is known to exert potent antifungal activity against the pathogenic yeast Candida albicans. This monoterpene has been the subject of a considerable number of investigations that uncovered extensive pharmacological properties, including antifungal and antibacterial effects. However, its mechanism of action remains elusive. Here, we used integrative chemogenomic approaches, including genome-scale chemical-genetic and transcriptional profiling, to uncover the mechanism of action of carvacrol associated with its antifungal property. Our results clearly demonstrated that fungal cells require the unfolded protein response (UPR) signaling pathway to resist carvacrol. The mutants most sensitive to carvacrol in our genome-wide competitive fitness assay in the yeast Saccharomyces cerevisiae expressed mutations of the transcription factor Hac1 and the endonuclease Ire1, which is required for Hac1 activation by removing a nonconventional intron from the 3' region of HAC1 mRNA. Confocal fluorescence live-cell imaging revealed that carvacrol affects the morphology and the integrity of the endoplasmic reticulum (ER). Transcriptional profiling of pathogenic yeast C. albicans cells treated with carvacrol demonstrated a bona fide UPR transcriptional signature. Ire1 activity detected by the splicing of HAC1 mRNA in C. albicans was activated by carvacrol. Furthermore, carvacrol was found to potentiate antifungal activity of the echinocandin antifungal caspofungin and UPR inducers dithiothreitol and tunicamycin against C. albicans. This comprehensive chemogenomic investigation demonstrated that carvacrol exerts its antifungal activity by altering ER integrity, leading to ER stress and the activation of the UPR to restore protein-folding homeostasis. PMID:26014932

  6. Equilibrium and thermodynamic studies on biosorption of Pb(II) onto Candida albicans biomass

    International Nuclear Information System (INIS)

    Biosorption of Pb(II) ions from aqueous solutions was studied in a batch system by using Candida albicans. The optimum conditions of biosorption were determined by investigating the initial metal ion concentration, contact time, temperature, biosorbent dose and pH. The extent of metal ion removed increased with increasing contact time, initial metal ion concentration and temperature. Biosorption equilibrium time was observed in 30 min. The Freundlich and Langmuir adsorption models were used for the mathematical description of biosorption equilibrium and isotherm constants were also evaluated. The maximum biosorption capacity of Pb(II) on C. albicans was determined as 828.50 ± 1.05, 831.26 ± 1.30 and 833.33 ± 1.12 mg g-1, respectively, at different temperatures (25, 35 and 45 deg. C). Biosorption showed pseudo second-order rate kinetics at different initial concentration of Pb(II) and different temperatures. The activation energy of the biosorption (Ea) was estimated as 59.04 kJ mol-1 from Arrhenius equation. Using the equilibrium constant value obtained at different temperatures, the thermodynamic properties of the biosorption (ΔGo, ΔHo and ΔSo) were also determined. The results showed that biosorption of Pb(II) ions on C. albicans were endothermic and spontaneous. The optimum initial pH for Pb(II) was determined as pH 5.0. FTIR spectral analysis of Pb(II) adsorbed and unadsorbed C. albicans biomass was also discussed

  7. Caveats in the investigation of form-specific molecules of Candida albicans.

    OpenAIRE

    Brawner, D L; Cutler, J E; Beatty, W. L.

    1990-01-01

    Numerous reports purporting the existence of form-specific antigens of Candida albicans have been published, but it is generally unclear whether antigenic variability is an acceptable alternative interpretation. In this study, we used indirect immunofluorescence and immunogold electron microscopy to determine the distribution and form specificities of two antigens during yeast and hyphal growth in several defined and complex media. The results confirmed that antigen expression varies with len...

  8. Antifungal activities of Terminalia ivorensis A. Chev. bark extracts against Candida albicans and Aspergillus fumigatus.

    OpenAIRE

    Ouattara Sitapha; KPOROU KOUASSI ELISEE; Djaman Allico Joseph

    2013-01-01

    Abstract The present study was undertaken to evaluate in vitro antifungal activity of aqueous and hydroacoholic extracts from bark of Terminalia ivorensis A. Chev. (Combretaceae). In vitro antifungal activity of all the extracts was done by agar slant double dilution method. Candida albicans and Aspergillus fumigatus clinically important strains were used for the study. ketoconazole was used as standards for antifungal assay. Antifungal activity was determinated by evaluating of antifung...

  9. TLR2, TLR4 and Dectin-1 signalling in hematopoietic stem and progenitor cells determines the antifungal phenotype of the macrophages they produce.

    Science.gov (United States)

    Megías, Javier; Martínez, Alba; Yáñez, Alberto; Goodridge, Helen S; Gozalbo, Daniel; Gil, M Luisa

    2016-05-01

    TLRs represent an attractive target for the stimulation of myeloid cell production by HSPCs. We have previously demonstrated that HSPCs use TLR2 to sense Candida albicans in vivo and induce the production of macrophages. In this work, we used an in vitro model of HSPCs differentiation to investigate the functional consequences for macrophages of exposure of HSPCs to various PAMPs and C. albicans cells. Mouse HSPCs (Lin(-) cells) were cultured with M-CSF to induce macrophage differentiation, in the presence or absence of the following PRR agonists: Pam3CSK4 (TLR2 ligand), LPS (TLR4 ligand), depleted zymosan (which only activates Dectin-1), or C. albicans yeasts (which activate several PRRs, but principally TLR2 and Dectin-1). Our data show that these PAMPs differentially impact the anti-microbial function of the macrophages produced by the exposed HSPCs. Pure TLR2 and TLR4 ligands generate macrophages with a diminished ability to produce inflammatory cytokines. In contrast, HSPCs activation in response to C. albicans leads to the generation of macrophages that are better prepared to deal with the infection, as they produce higher amounts of inflammatory cytokines and have higher fungicidal capacity than control macrophages. Therefore, the tailored manipulation of the differentiation process may help to boost the innate immune response to infection. PMID:26828664

  10. Plasma membrane organization promotes virulence of the human fungal pathogen Candida albicans.

    Science.gov (United States)

    Douglas, Lois M; Konopka, James B

    2016-03-01

    Candida albicans is a human fungal pathogen capable of causing lethal systemic infections. The plasma membrane plays key roles in virulence because it not only functions as a protective barrier, it also mediates dynamic functions including secretion of virulence factors, cell wall synthesis, invasive hyphal morphogenesis, endocytosis, and nutrient uptake. Consistent with this functional complexity, the plasma membrane is composed of a wide array of lipids and proteins. These components are organized into distinct domains that will be the topic of this review. Some of the plasma membrane domains that will be described are known to act as scaffolds or barriers to diffusion, such as MCC/eisosomes, septins, and sites of contact with the endoplasmic reticulum. Other zones mediate dynamic processes, including secretion, endocytosis, and a special region at hyphal tips that facilitates rapid growth. The highly organized architecture of the plasma membrane facilitates the coordination of diverse functions and promotes the pathogenesis of C. albicans. PMID:26920878

  11. The effect of ultraviolet radiation on the pathogenesis of Candida albicans in mice

    Energy Technology Data Exchange (ETDEWEB)

    Denkins, Y.M.

    1991-01-01

    This dissertation addresses questions concerning the effects of UV radiation on the pathogenesis of opportunistic fungal pathogens such as Candida albicans. UV radiation decreased the survival of Candida-infected mice; however, no correlation was found between suppression of the delayed type hypersensitivity (DTH) response and the course of lethal infection. This suggested that DTH was not protective against lethal disease with this organism. UV radiation also changed the persistence of the organism in the internal organs. UV-irradiated, infected animals had increased numbers of Candida in their kidneys compared to non-irradiated mice. Sensitization prior to UV irradiation aided clearance of the organism from the kidneys of UV-irradiated mice. These data show that UV radiation suppresses cell-mediated immunity to Candida albicans in mice and increases mortality of Candida-infected mice. Moreover, the data suggest that an increase in environmental UV radiation could increase the severity of pathogenic infections.

  12. The effect of ultraviolet radiation on the pathogenesis of Candida albicans in mice

    International Nuclear Information System (INIS)

    This dissertation addresses questions concerning the effects of UV radiation on the pathogenesis of opportunistic fungal pathogens such as Candida albicans. UV radiation decreased the survival of Candida-infected mice; however, no correlation was found between suppression of the delayed type hypersensitivity (DTH) response and the course of lethal infection. This suggested that DTH was not protective against lethal disease with this organism. UV radiation also changed the persistence of the organism in the internal organs. UV-irradiated, infected animals had increased numbers of Candida in their kidneys compared to non-irradiated mice. Sensitization prior to UV irradiation aided clearance of the organism from the kidneys of UV-irradiated mice. These data show that UV radiation suppresses cell-mediated immunity to Candida albicans in mice and increases mortality of Candida-infected mice. Moreover, the data suggest that an increase in environmental UV radiation could increase the severity of pathogenic infections

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

    Directory of Open Access Journals (Sweden)

    Nitin M Chauhan

    2013-12-01

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

  14. Modelling the regulation of thermal adaptation in Candida albicans, a major fungal pathogen of humans.

    Directory of Open Access Journals (Sweden)

    Michelle D Leach

    Full Text Available Eukaryotic cells have evolved mechanisms to sense and adapt to dynamic environmental changes. Adaptation to thermal insults, in particular, is essential for their survival. The major fungal pathogen of humans, Candida albicans, is obligately associated with warm-blooded animals and hence occupies thermally buffered niches. Yet during its evolution in the host it has retained a bona fide heat shock response whilst other stress responses have diverged significantly. Furthermore the heat shock response is essential for the virulence of C. albicans. With a view to understanding the relevance of this response to infection we have explored the dynamic regulation of thermal adaptation using an integrative systems biology approach. Our mathematical model of thermal regulation, which has been validated experimentally in C. albicans, describes the dynamic autoregulation of the heat shock transcription factor Hsf1 and the essential chaperone protein Hsp90. We have used this model to show that the thermal adaptation system displays perfect adaptation, that it retains a transient molecular memory, and that Hsf1 is activated during thermal transitions that mimic fever. In addition to providing explanations for the evolutionary conservation of the heat shock response in this pathogen and the relevant of this response to infection, our model provides a platform for the analysis of thermal adaptation in other eukaryotic cells.

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

    LENUS (Irish Health Repository)

    Martin, Ronny

    2011-04-01

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

  16. BAY 41-2272 activates host defence against local and disseminated Candida albicans infections

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    Paulo Vítor Soeiro-Pereira

    2015-02-01

    Full Text Available In our previous study, we have found that 5-cyclopropyl-2-[1-(2-fluoro-benzyl-1H-pyrazolo[3,4-b]pyridine-3-yl]-pyrimidin-4-ylamine (BAY 41-2272, a guanylate cyclase agonist, activates human monocytes and the THP-1 cell line to produce the superoxide anion, increasing in vitro microbicidal activity, suggesting that this drug can be used to modulate immune functioning in primary immunodeficiency patients. In the present work, we investigated the potential of the in vivo administration of BAY 41-2272 for the treatment of Candida albicans and Staphylococcus aureus infections introduced via intraperitoneal and subcutaneous inoculation. We found that intraperitoneal treatment with BAY 41-2272 markedly increased macrophage-dependent cell influx to the peritoneum in addition to macrophage functions, such as spreading, zymosan particle phagocytosis and nitric oxide and phorbol myristate acetate-stimulated hydrogen peroxide production. Treatment with BAY 41-2272 was highly effective in reducing the death rate due to intraperitoneal inoculation of C. albicans, but not S. aureus. However, we found that in vitro stimulation of peritoneal macrophages with BAY 41-2272 markedly increased microbicidal activities against both pathogens. Our results show that the prevention of death by the treatment of C. albicans-infected mice with BAY 41-2272 might occur primarily by the modulation of the host immune response through macrophage activation.

  17. Morphogenic regulator EFG1 affects the drug susceptibilities of pathogenic Candida albicans.

    Science.gov (United States)

    Prasad, Tulika; Hameed, Saif; Manoharlal, Raman; Biswas, Sudipta; Mukhopadhyay, Chinmay K; Goswami, Shyamal K; Prasad, Rajendra

    2010-08-01

    This study shows that the morphogenic regulator EFG1 level affects the drug susceptibilities of Candida albicans when grown on solid growth media. The Deltaefg1 mutant showed sensitivity particularly to those drugs that target ergosterol or its metabolism. Efg1p disruption showed a gene-dosage effect on drug susceptibilities and resulted in enhanced susceptibility to drugs in the homozygous mutant as compared with the wild type, heterozygous and revertant strains. The enhanced sensitivity to drugs was independent of the status of ATP-binding cassette and MFS multidrug efflux pumps of C. albicans. The Deltaefg1 mutant displayed increased membrane fluidity that coincided with the downregulation of ERG11 and upregulation of OLE1 and ERG3, leading to enhanced passive diffusion of drugs. Interestingly, Deltaefg1 mutant cells displayed enhanced levels of endogenous ROS levels. Notably, the higher levels of ROS in the Deltaefg1 mutant could be reversed by the addition of antioxidants. However, the restoration of ROS levels did not reverse the drug sensitivities of the Deltaefg1 mutant. Taken together, we, for the first time, establish a new role to EFG1 in affecting the drug susceptibilities of C. albicans cells, independent of ROS and known drug efflux mechanisms. PMID:20491944

  18. Contribution of Fdh3 and Glr1 to Glutathione Redox State, Stress Adaptation and Virulence in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Anna T Tillmann

    Full Text Available The major fungal pathogen of humans, Candida albicans, is exposed to reactive nitrogen and oxygen species following phagocytosis by host immune cells. In response to these toxins, this fungus activates potent anti-stress responses that include scavenging of reactive nitrosative and oxidative species via the glutathione system. Here we examine the differential roles of two glutathione recycling enzymes in redox homeostasis, stress adaptation and virulence in C. albicans: glutathione reductase (Glr1 and the S-nitrosoglutathione reductase (GSNOR, Fdh3. We show that the NADPH-dependent Glr1 recycles GSSG to GSH, is induced in response to oxidative stress and is required for resistance to macrophage killing. GLR1 deletion increases the sensitivity of C. albicans cells to H2O2, but not to formaldehyde or NO. In contrast, Fdh3 detoxifies GSNO to GSSG and NH3, and FDH3 inactivation delays NO adaptation and increases NO sensitivity. C. albicans fdh3⎔ cells are also sensitive to formaldehyde, suggesting that Fdh3 also contributes to formaldehyde detoxification. FDH3 is induced in response to nitrosative, oxidative and formaldehyde stress, and fdh3Δ cells are more sensitive to killing by macrophages. Both Glr1 and Fdh3 contribute to virulence in the Galleria mellonella and mouse models of systemic infection. We conclude that Glr1 and Fdh3 play differential roles during the adaptation of C. albicans cells to oxidative, nitrosative and formaldehyde stress, and hence during the colonisation of the host. Our findings emphasise the importance of the glutathione system and the maintenance of intracellular redox homeostasis in this major pathogen.

  19. Probiotic lactobacillus and estrogen effects on vaginal epithelial gene expression responses to Candida albicans

    Directory of Open Access Journals (Sweden)

    Wagner R

    2012-06-01

    Full Text Available Abstract Background Vaginal epithelial cells have receptors, signal transduction mechanisms, and cytokine secretion capabilities to recruit host defenses against Candida albicans infections. This research evaluates how probiotic lactobacilli affect the defensive epithelial response. Methods This study used quantitative reverse transcription-polymerase chain reaction assay (qRT-PCR, flow cytometry, and a multiplex immunoassay to observe changes in the regulation of gene expression related to cytokine responses in the VK2 (E6/E7 vaginal epithelial cell line treated with 17β-estradiol, exposed to probiotic Lactobacillus rhamnosus GR-1® and Lactobacillus reuteri RC-14® and challenged with C. albicans. Data were statistically evaluated by repeated measures analysis of variance and paired t-tests where appropriate. Results C. albicans induced mRNA expression of genes related to inflammatory cytokine responses associated with nuclear factor-kappa B (NF-κB and mitogen-activated protein kinase (MAPK signal transduction pathways. 17β-estradiol suppressed expression of interleukin-1α (IL-1α, IL-6, IL-8, and tumor necrosis factor alpha (TNFα mRNA. Probiotic lactobacilli suppressed C. albicans-induced nuclear factor-kappa B inhibitor kinase kinase alpha (Iκκα, Toll-like receptor-2 (TLR2, TLR6, IL-8, and TNFα, also suggesting inhibition of NF-κB signaling. The lactobacilli induced expression of IL-1α, and IL-1β mRNA, which was not inhibited by curcumin, suggesting that they induce an alternate inflammatory signal transduction pathway to NF-κB, such as the mitogen activated protein kinase and activator protein-1 (MAPK/AP-1 signal transduction pathway. Curcumin inhibited IL-13 secretion, suggesting that expression of this cytokine is mainly regulated by NF-κB signaling in VK2 cells. Conclusions The results suggest that C. albicans infection induces pro-inflammatory responses in vaginal epithelial cells, and estrogen and lactobacilli suppress

  20. Probiotic (yogurt) containing Lactobacillus gasseri OLL2716 is effective for preventing Candida albicans-induced mucosal inflammation and proliferation in the forestomach of diabetic rats.

    Science.gov (United States)

    Terayama, Yui; Matsuura, Tetsuro; Uchida, Masayuki; Narama, Isao; Ozaki, Kiyokazu

    2016-06-01

    Oral and esophageal candidiasis sometimes leads to mucosal hyperplasia, and progresses to carcinoma. We have produced an animal model for hyperplastic mucosal candidiasis in the forestomach that has a proliferative lesion of the squamous epithelium with chronic inflammation and C. albicans infection, some of which advanced to squamous cell carcinoma. There are many reports of the antibacterial effects of probiotics, but consensus about their antifungal effect has not been reached. In the present study, we investigate whether probiotic (yogurt) containing Lactobacillus gasseri OLL2716 (LG21 yogurt) can prevent proliferative and inflammatory changes caused by C. albicans in this mucosal candidiasis animal model. Diabetes was induced in 8-week-old WBN/Kob rats by intravenous administration of alloxan. One group of diabetic rats received a saline containing C. albicans and LG21 yogurt orally (DC+LG21 group) for 30 weeks, and another group received only C. albicans (DC group) for 30 weeks. They were sacrificed at 40 weeks of age, and analyzed histopathologically. In the DC+LG21 group, squamous hyperplasia at the greater curvature was significantly milder, and the Ki-67 positive index was significantly lower compared with the DC group. Suppurative inflammation with C. albicans also tended to be suppressed at the greater curvature. These findings suggest that probiotic (yogurt) containing Lactobacillus gasseri OLL2716 can suppress squamous hyperplastic change and inflammation associated with C. albicans infection in the forestomach. PMID:26691696

  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. MBL-mediated opsonophagocytosis of Candida albicans by human neutrophils is coupled with intracellular Dectin-1-triggered ROS production.

    Directory of Open Access Journals (Sweden)

    Dongsheng Li

    Full Text Available Mannan-binding lectin (MBL, a lectin homologous to C1q, greatly facilitates C3/C4-mediated opsonophagocytosis of Candida albicans (C. albicans by human neutrophils, and has the capacity to bind to CR1 (CD35 expressed on circulating neutrophils. The intracellular pool of neutrophil Dectin-1 plays a critical role in stimulating the reactive oxygen species (ROS generation through recognition of β-1,3-glucan component of phagocytized zymosan or yeasts. However, little is known about whether MBL can mediate the opsonophagocytosis of Candida albicans by neutrophils independent of complement activation, and whether MBL-mediated opsonophagocytosis influence the intracellular expression of Dectin-1 and ROS production. Here we showed that the inhibited phagocytic efficiency of neutrophils as a result of blockage of Dectin-1 was compensated by exogenous MBL alone in a dose-dependent manner. Furthermore, the expressions of Dectin-1 at mRNA and intracellular protein levels were significantly up-regulated in neutrophils stimulated by MBL-pre-incubated C. albicans, while the expression of surface Dectin-1 remained almost unchanged. Nevertheless, the stimulated ROS production in neutrophils was partly and irreversibly inhibited by blockage of Dectin-1 in the presence of exogenous MBL. Confocal microscopy examination showed that intracellular Dectin-1 was recruited and co-distributed with ROS on the surface of some phagocytized yeasts. The β-1,3-glucanase digestion test further suggested that the specific recognition and binding site of human Dectin-1 is just the β-1,3-glucan moiety on the cell wall of C. albicans. These data demonstrate that MBL has an ability to mediate the opsonophagocytosis of Candida albicans by human neutrophils independent of complement activation, which is coupled with intracellular Dectin-1-triggered ROS production.

  3. Inhibition of Candida albicans by Fluvastatin Is Dependent on pH

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    Martin Schmidt

    2009-01-01

    Full Text Available The cholesterol-lowering drug fluvastatin (FS has an inhibitory effect on the growth of the pathogenic yeast Candida albicans that is dependent on the pH of the medium. At the low pH value of the vagina, FS is growth inhibitory at low and at high concentrations, while at intermediate concentrations (1–10 mM, it has no inhibitory effect. Examination of the effect of the common antifungal drug fluconazole in combination with FS demonstrates drug interactions in the low concentration range. Determination of intracellular stress and the activity of the FS target enzyme HMG-CoA reductase confirm our hypothesis that in the intermediate dose range adjustments to the sterol biosynthesis pathway can compensate for the action of FS. We conclude that the pH dependent uptake of FS across yeast membranes might make FS combination therapy an attractive possibility for treatment of vaginal C. albicans infections.

  4. Thiamin Pyrimidine Biosynthesis in Candida albicans: A Remarkable Reaction between Histidine and Pyridoxal Phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Rung-Yi; Huang, Siyu; Fenwick, Michael K.; Hazra, Amrita; Zhang, Yang; Rajashankar, Kanagalaghatta; Philmus, Benjamin; Kinsland, Cynthia; Sanders, Jennie Mansell; Ealick, Steven E.; Begley, Tadhg P. (Cornell); (TAM)

    2012-06-26

    In Saccharomyces cerevisiae, thiamin pyrimidine is formed from histidine and pyridoxal phosphate (PLP). The origin of all of the pyrimidine atoms has been previously determined using labeling studies and suggests that the pyrimidine is formed using remarkable chemistry that is without chemical or biochemical precedent. Here we report the overexpression of the closely related Candida albicans pyrimidine synthase (THI5p) and the reconstitution and preliminary characterization of the enzymatic activity. A structure of the C. albicans THI5p shows PLP bound at the active site via an imine with Lys62 and His66 in close proximity to the PLP. Our data suggest that His66 of the THI5 protein is the histidine source for pyrimidine formation and that the pyrimidine synthase is a single-turnover enzyme.

  5. In vitro activity of zinc oxide-eugenol and glass ionomer cements on Candida albicans Atividade in vitro dos cimentos de óxido de zinco e eugenol e ionômero de vidro sobre Candida albicans

    Directory of Open Access Journals (Sweden)

    Anna Carolina Aguiar Cassanho

    2005-06-01

    Full Text Available 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. The results were expressed as values of logarithms of colony-forming units per milliliter (log CFU/mL and were analyzed statistically by Kruskal-Wallis ANOVA. After 48 h of incubation, the ZOE group presented no growth of C. albicans. GIC and control groups presented similar mean values at all tested periods. According to the results obtained, it could be concluded that, under the experimental conditions, ZOE cement was more effective in vitro against C. albicans than GIC.O objetivo deste estudo foi avaliar in vitro a atividade antimicrobiana dos cimentos de ionômero de vidro (CIV e óxido de zinco e eugenol (OZE sobre Candida albicans. Corpos-de-prova padronizados de CIV e OZE foram mantidos em contato com suspensão (1 ´ 10(6 células/ml de C. albicans a 37°C por 24 horas, 48 horas ou 7 dias. Um grupo controle sem nenhum cimento teste foi incluído. Após o período de incubação, alíquotas de 0,1 ml foram semeadas em ágar Sabouraud e o número de colônias foi contado. Os resultados foram expressos em logaritmos de valores de unidades formadoras de colônias por ml (log UFC/mL e analisados estatisticamente pelo teste ANOVA Kruskal-Wallis. Após 48 horas de incubação, o grupo OZE não apresentou crescimento de C. albicans. Os grupos CIV e controle apresentaram médias similares em todos os períodos testados. De acordo com os resultados obtidos, pode ser concluído que, sob as condições experimentais testadas, o cimento OZE apresentou-se mais efetivo in

  6. Glucanase Induces Filamentation of the Fungal Pathogen Candida albicans

    OpenAIRE

    Xu, H.; Nobile, CJ; Dongari-Bagtzoglou, A.

    2013-01-01

    Candida albicans is the most common human fungal pathogen. Many organisms, including C. albicans, secrete glucanases under different environmental conditions. Here, we report a novel role for beta-1, 3- glucanase in inducing Candida albicans to form filaments at 22°C and enhancing filamentation at 37°C in nutrient-rich medium. Quorum sensing, the efg1-signaling and cek1 MAP kinase pathways are involved in this process. Our data suggest that the natural antifungal agent beta-glucanase may supp...

  7. Ibuprofen reverts antifungal resistance on Candida albicans showing overexpression of CDR genes.

    Science.gov (United States)

    Ricardo, Elisabete; Costa-de-Oliveira, Sofia; Dias, Ana Silva; Guerra, José; Rodrigues, Acácio Gonçalves; Pina-Vaz, Cidália

    2009-06-01

    Several mechanisms may be associated with Candida albicans resistance to azoles. Ibuprofen was described as being able to revert resistance related to efflux activity in Candida. The aim of this study was to uncover the molecular base of antifungal resistance in C. albicans clinical strains that could be reverted by ibuprofen. Sixty-two clinical isolates and five control strains of C. albicans were studied: the azole susceptibility phenotype was determined according to the Clinical Laboratory for Standards Institute, M27-A2 protocol and minimal inhibitory concentration values were recalculated with ibuprofen (100 microg mL(-1)); synergistic studies between fluconazole and FK506, a Cdr1p inhibitor, were performed using an agar disk diffusion assay and were compared with ibuprofen results. Gene expression was quantified by real-time PCR, with and without ibuprofen, regarding CDR1, CDR2, MDR1, encoding for efflux pumps, and ERG11, encoding for azole target protein. A correlation between susceptibility phenotype and resistance gene expression profiles was determined. Ibuprofen and FK506 showed a clear synergistic effect when combined with fluconazole. Resistant isolates reverting to susceptible after incubation with ibuprofen showed CDR1 and CDR2 overexpression especially of the latter. Conversely, strains that did not revert displayed a remarkable increase in ERG11 expression along with CDR genes. Ibuprofen did not alter resistance gene expression significantly (P>0.05), probably acting as a Cdrp blocker. PMID:19416368

  8. Screening attenuation of coaxial cables determined in GTEM-cells

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    A. Knobloch

    2004-01-01

    Full Text Available This paper describes the determination of the screening attenuation with a GTEM cell. An analytical part gives the link between the voltage at the cell port and the total radiated power. The next section investigates the optimal cable setup in the cell. With a measurement of the common mode current on the cable and a simulation of the radiation resistance the loop antenna characteristic of the cable setup could be verified. It is shown that the use of ferrit cores decrease the difference between the maximum and the minimum screening attenuation. The determination of great screening attenuation could be improved with the use of N-type measurement cables. A comparison between this GTEM cell method and the standard methods shows a good agreement.

  9. Fungal morphogenetic pathways are required for the hallmark inflammatory response during Candida albicans vaginitis.

    Science.gov (United States)

    Peters, Brian M; Palmer, Glen E; Nash, Andrea K; Lilly, Elizabeth A; Fidel, Paul L; Noverr, Mairi C

    2014-02-01

    Vulvovaginal candidiasis, caused primarily by Candida albicans, presents significant health issues for women of childbearing age. As a polymorphic fungus, the ability of C. albicans to switch between yeast and hyphal morphologies is considered its central virulence attribute. Armed with new criteria for defining vaginitis immunopathology, the purpose of this study was to determine whether the yeast-to-hypha transition is required for the hallmark inflammatory responses previously characterized during murine vaginitis. Kinetic analyses of vaginal infection with C. albicans in C57BL/6 mice demonstrated that fungal burdens remained constant throughout the observation period, while polymorphonuclear leukocyte (PMN), S100A8, and interleukin-1β levels obtained from vaginal lavage fluid increased by day 3 onward. Lactate dehydrogenase activity was also positively correlated with increased effectors of innate immunity. Additionally, immunodepletion of neutrophils in infected mice confirmed a nonprotective role for PMNs during vaginitis. Determination of the importance of fungal morphogenesis during vaginitis was addressed with a two-pronged approach. Intravaginal inoculation of mice with C. albicans strains deleted for key transcriptional regulators (bcr1Δ/Δ, efg1Δ/Δ, cph1Δ/Δ, and efg1Δ/Δ cph1Δ/Δ) controlling the yeast-to-hypha switch revealed a crucial role for morphogenetic signaling through the Efg1 and, to a lesser extent, the Bcr1 pathways in contributing to vaginitis immunopathology. Furthermore, overexpression of transcription factors NRG1 and UME6, to maintain yeast and hyphal morphologies, respectively, confirmed the importance of morphogenesis in generating innate immune responses in vivo. These results highlight the yeast-to-hypha switch and the associated morphogenetic response as important virulence components for the immunopathogenesis of Candida vaginitis, with implications for transition from benign colonization to symptomatic infection. PMID

  10. Efek Antijamur Minyak Atsiri Jahe Putih Kecil (Zingiber officinale var. Amarum terhadap Candida Albicans

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    Huanny Satriyani

    2015-10-01

    Full Text Available The side effects of many antifungal drugs make it necessary to find an herbal alternative with reduced side effects. Many herbals are knwon to have an antifungal effect, including ginger with its volatile oil composition. However, the specific antifungal effect and optimal concentration of the volatile oil from Zingiber officinale var. amarum against C. albicans is not yet known. This research was done to verify the antifungal effect of Zingiber officinale var. amarum volatile oil on C. albicans, to determine its optimal concentration, and to determine the relation between the volatile oil was provided by water and steam distillation of BALITTRO, Bogor. The colonies were double counted in two steps. First, the volatile oil at concentrations of 100%, 50%, 25%, 12.5%, 6.25%, 3.125%, 1.56% and 0.78% were applied for treatment, wheras in the second step concentrations of 100%, 90%, 80%, 70%, 60%, and 50% were used. In the disk diffusion method, the volatile oil concentrations of 100%, 70%, 60%, 50%, 25%, 12.5%, 6.25% and 3.125% were applied in triplicate in Petri dishes containing C. albicans by using 6 mm blank disks. Result: Mann-Whitney test showed the significant decrease of the colonies between 6.25% and 3.125% of the volatile oil concentration (α = 0.021, and also between the volatile oil concentration 6.25% and the control group (α = 0.014. The Spearman test showed a positive and strong correlation between the volatile oil of Zingiber officinale var. amarum and its inhibition zone (r = 0.91. Conclusion: The volatile oil of Zingiber officinale var. amarum has an antifungal effect against C. albicans with an optimal concentration of 6.25%, and increasing volatile oil concentration is followed by increasing inhibition zone.

  11. Sustained Nitric Oxide-Releasing Nanoparticles Induce Cell Death in Candida albicans Yeast and Hyphal Cells, Preventing Biofilm Formation In Vitro and in a Rodent Central Venous Catheter Model.

    Science.gov (United States)

    Ahmadi, Mohammed S; Lee, Hiu Ham; Sanchez, David A; Friedman, Adam J; Tar, Moses T; Davies, Kelvin P; Nosanchuk, Joshua D; Martinez, Luis R

    2016-04-01

    Candida albicansis a leading nosocomial pathogen. Today, candidal biofilms are a significant cause of catheter infections, and such infections are becoming increasingly responsible for the failure of medical-implanted devices.C. albicansforms biofilms in which fungal cells are encased in an autoproduced extracellular polysaccharide matrix. Consequently, the enclosed fungi are protected from antimicrobial agents and host cells, providing a unique niche conducive to robust microbial growth and a harbor for recurring infections. Here we demonstrate that a recently developed platform comprised of nanoparticles that release therapeutic levels of nitric oxide (NO-np) inhibits candidal biofilm formation, destroys the extracellular polysaccharide matrices of mature fungal biofilms, and hinders biofilm development on surface biomaterials such as the lumen of catheters. We found NO-np to decrease both the metabolic activity of biofilms and the cell viability ofC. albicansin vitroandin vivo Furthermore, flow cytometric analysis found NO-np to induce apoptosis in biofilm yeast cellsin vitro Moreover, NO-np behave synergistically when used in combination with established antifungal drug therapies. Here we propose NO-np as a novel treatment modality, especially in combination with standard antifungals, for the prevention and/or remediation of fungal biofilms on central venous catheters and other medical devices. PMID:26810653

  12. Determinants of academic performance in children with sickle cell anaemia

    OpenAIRE

    Ezenwosu, Osita U; Emodi, Ifeoma J; Ikefuna, Anthony N; Chukwu, Barth F; Osuorah, Chidiebere D

    2013-01-01

    Background Some factors are known to influence the academic performance of children with Sickle Cell Anaemia (SCA). Information on their effects in these children is limited in Nigeria. The factors which influence academic performance of children with SCA in Enugu, Nigeria are determined in this study. Methods Consecutive children with SCA aged 5–11 years were recruited at the weekly sickle cell clinic of the University of Nigeria Teaching Hospital (UNTH) Enugu, Nigeria. Their age- and sex- m...

  13. The Use of Chitosan to Enhance Photodynamic Inactivation against Candida albicans and Its Drug-Resistant Clinical Isolates

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    Tsuimin Tsai

    2013-04-01

    Full Text Available Drug-resistant Candida infection is a major health concern among immunocompromised patients. Antimicrobial photodynamic inactivation (PDI was introduced as an alternative treatment for local infections. Although Candida (C. has demonstrated susceptibility to PDI, high doses of photosensitizer (PS and light energy are required, which may be harmful to eukaryotic human cells. This study explores the capacity of chitosan, a polycationic biopolymer, to increase the efficacy of PDI against C. albicans, as well as fluconazole-resistant clinical isolates in planktonic or biofilm states. Chitosan was shown to effectively augment the effect of PDI mediated by toluidine blue O (TBO against C. albicans that were incubated with chitosan for 30 min following PDI. Chitosan at concentrations as low as 0.25% eradicated C. albicans; however, without PDI treatment, chitosan alone did not demonstrate significant antimicrobial activity within the 30 min of incubation. These results suggest that chitosan only augmented the fungicidal effect after the cells had been damaged by PDI. Increasing the dosage of chitosan or prolonging the incubation time allowed a reduction in the PDI condition required to completely eradicate C. albicans. These results clearly indicate that combining chitosan with PDI is a promising antimicrobial approach to treat infectious diseases.

  14. Phenotypic diversity and correlation between white-opaque switching and the CAI microsatellite locus in Candida albicans.

    Science.gov (United States)

    Hu, Jian; Guan, Guobo; Dai, Yu; Tao, Li; Zhang, Jianzhong; Li, Houmin; Huang, Guanghua

    2016-08-01

    Candida albicans is a commensal fungal pathogen that is often found as part of the human microbial flora. The aim of the present study was to establish a relationship between diverse genotypes and phenotypes of clinical isolates of C. albicans. Totally 231 clinical isolates were collected and used for genotyping and phenotypic switching analysis. Based on the microsatellite locus (CAI) genotyping assay, 65 different genotypes were identified, and some dominant types were found in certain human niches. For example, the genotypes of 30-44 and 30-45 were enriched in vaginal infection samples. C. albicans has a number of morphological forms including the single-celled yeasts, multicellular filaments, white, and opaque cell types. The relationship between the CAI genotype and the ability to undergo phenotypic switching was examined in the clinical isolates. We found that the strains with longer CAA/G repeats in both alleles of the CAI locus were more opaque competent. We also discovered that some MTL heterozygous (a/alpha) isolates could undergo white-opaque switching when grown on regular culture medium (containing glucose as the sole carbon source). Our study establishes a link between phenotypic switching and genotypes of the CAI microsatellite locus in clinical isolates of C. albicans. PMID:26832141

  15. Metabolic gene clusters encoding the enzymes of two branches of the 3-oxoadipate pathway in the pathogenic yeast Candida albicans.

    Science.gov (United States)

    Gérecová, Gabriela; Neboháčová, Martina; Zeman, Igor; Pryszcz, Leszek P; Tomáška, Ľubomír; Gabaldón, Toni; Nosek, Jozef

    2015-05-01

    The pathogenic yeast Candida albicans utilizes hydroxyderivatives of benzene via the catechol and hydroxyhydroquinone branches of the 3-oxoadipate pathway. The genetic basis and evolutionary origin of this catabolic pathway in yeasts are unknown. In this study, we identified C. albicans genes encoding the enzymes involved in the degradation of hydroxybenzenes. We found that the genes coding for core components of the 3-oxoadipate pathway are arranged into two metabolic gene clusters. Our results demonstrate that C. albicans cells cultivated in media containing hydroxybenzene substrates highly induce the transcription of these genes as well as the corresponding enzymatic activities. We also found that C. albicans cells assimilating hydroxybenzenes cope with the oxidative stress by upregulation of cellular antioxidant systems such as alternative oxidase and catalase. Moreover, we investigated the evolution of the enzymes encoded by these clusters and found that most of them share a particularly sparse phylogenetic distribution among Saccharomycotina, which is likely to have been caused by extensive gene loss. We exploited this fact to find co-evolving proteins that are suitable candidates for the missing enzymes of the pathway. PMID:25743787

  16. Genome-Wide Transposon Mutagenesis in Saccharomyces cerevisiae and Candida albicans

    Science.gov (United States)

    Xu, Tao; Bharucha, Nikë; Kumar, Anuj

    2016-01-01

    Transposon mutagenesis is an effective method for generating large sets of random mutations in target DNA, with applicability toward numerous types of genetic screens in prokaryotes, single-celled eukaryotes, and metazoans alike. Relative to methods of random mutagenesis by chemical/UV treatment, transposon insertions can be easily identified in mutants with phenotypes of interest. The construction of transposon insertion mutants is also less labor-intensive on a genome-wide scale than methods for targeted gene replacement, although transposon insertions are not precisely targeted to a specific residue, and thus coverage of the target DNA can be problematic. The collective advantages of transposon mutagenesis have been well demonstrated in studies of the budding yeast Saccharomyces cerevisiae and the related pathogenic yeast Candida albicans, as transposon mutagenesis has been used extensively for phenotypic screens in both yeasts. Consequently, we present here protocols for the generation and utilization of transposon-insertion DNA libraries in S. cerevisiae and C. albicans. Specifically, we present methods for the large-scale introduction of transposon insertion alleles in a desired strain of S. cerevisiae. Methods are also presented for transposon mutagenesis of C. albicans, encompassing both the construction of the plasmid-based transposon-mutagenized DNA library and its introduction into a desired strain of Candida. In total, these methods provide the necessary information to implement transposon mutagenesis in yeast, enabling the construction of large sets of identifiable gene disruption mutations, with particular utility for phenotypic screening in nonstandard genetic backgrounds. PMID:21815095

  17. CO(2) acts as a signalling molecule in populations of the fungal pathogen Candida albicans.

    Science.gov (United States)

    Hall, Rebecca A; De Sordi, Luisa; Maccallum, Donna M; Topal, Hüsnü; Eaton, Rebecca; Bloor, James W; Robinson, Gary K; Levin, Lonny R; Buck, Jochen; Wang, Yue; Gow, Neil A R; Steegborn, Clemens; Mühlschlegel, Fritz A

    2010-01-01

    When colonising host-niches or non-animated medical devices, individual cells of the fungal pathogen Candida albicans expand into significant biomasses. Here we show that within such biomasses, fungal metabolically generated CO(2) acts as a communication molecule promoting the switch from yeast to filamentous growth essential for C. albicans pathology. We find that CO(2)-mediated intra-colony signalling involves the adenylyl cyclase protein (Cyr1p), a multi-sensor recently found to coordinate fungal responses to serum and bacterial peptidoglycan. We further identify Lys 1373 as essential for CO(2)/bicarbonate regulation of Cyr1p. Disruption of the CO(2)/bicarbonate receptor-site interferes selectively with C. albicans filamentation within fungal biomasses. Comparisons between the Drosophila melanogaster infection model and the mouse model of disseminated candidiasis, suggest that metabolic CO(2) sensing may be important for initial colonisation and epithelial invasion. Our results reveal the existence of a gaseous Candida signalling pathway and its molecular mechanism and provide insights into an evolutionary conserved CO(2)-signalling system. PMID:21124988

  18. CO(2 acts as a signalling molecule in populations of the fungal pathogen Candida albicans.

    Directory of Open Access Journals (Sweden)

    Rebecca A Hall

    Full Text Available When colonising host-niches or non-animated medical devices, individual cells of the fungal pathogen Candida albicans expand into significant biomasses. Here we show that within such biomasses, fungal metabolically generated CO(2 acts as a communication molecule promoting the switch from yeast to filamentous growth essential for C. albicans pathology. We find that CO(2-mediated intra-colony signalling involves the adenylyl cyclase protein (Cyr1p, a multi-sensor recently found to coordinate fungal responses to serum and bacterial peptidoglycan. We further identify Lys 1373 as essential for CO(2/bicarbonate regulation of Cyr1p. Disruption of the CO(2/bicarbonate receptor-site interferes selectively with C. albicans filamentation within fungal biomasses. Comparisons between the Drosophila melanogaster infection model and the mouse model of disseminated candidiasis, suggest that metabolic CO(2 sensing may be important for initial colonisation and epithelial invasion. Our results reveal the existence of a gaseous Candida signalling pathway and its molecular mechanism and provide insights into an evolutionary conserved CO(2-signalling system.

  19. Candida albicans PROTEIN PROFILE CHANGES IN RESPONSE TO THE BUTANOLIC EXTRACT OF Sapindus saponariaL.

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    Adriana FIORINI

    2016-01-01

    Full Text Available Candida albicans is an opportunistic human pathogen that is capable of causing superficial and systemic infections in immunocompromised patients. Extracts of Sapindus saponaria have been used as antimicrobial agents against various organisms. In the present study, we used a combination of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS to identify the changes in protein abundance of C. albicans after exposure to the minimal inhibitory concentration (MIC and sub-minimal inhibitory concentration (sub-MIC of the butanolic extract (BUTE of S. saponaria and also to fluconazole. A total of six different proteins with greater than 1.5 fold induction or repression relative to the untreated control cells were identified among the three treatments. In general, proteins/enzymes involved with the glycolysis (GPM1, ENO1, FBA1, amino acid metabolism (ILV5, PDC11 and protein synthesis (ASC1 pathways were detected. In conclusion, our findings reveal antifungal-induced changes in protein abundance of C. albicans. By using the previously identified components of the BUTE of S. saponaria(e.g., saponins and sesquiterpene oligoglycosides, it will be possible to compare the behavior of compounds with unknown mechanisms of action, and this knowledge will help to focus the subsequent biochemical work aimed at defining the effects of these compounds.

  20. Candida albicans biofilms do not trigger reactive oxygen species and evade neutrophil killing.

    Science.gov (United States)

    Xie, Zhihong; Thompson, Angela; Sobue, Takanori; Kashleva, Helena; Xu, Hongbin; Vasilakos, John; Dongari-Bagtzoglou, Anna

    2012-12-15

    Neutrophils are found within Candida albicans biofilms in vivo and could play a crucial role in clearing the pathogen from biofilms forming on catheters and mucosal surfaces. Our goal was to compare the antimicrobial activity of neutrophils against developing and mature C. albicans biofilms and identify biofilm-specific properties mediating resistance to immune cells. Antibiofilm activity was measured with the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)2H-tetrazolium-5-carboxanilide assay and a molecular Candida viability assay. Reactive oxygen species generation was assessed by measuring fluorescence of 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester in preloaded neutrophils. We found that mature biofilms were resistant to leukocytic killing and did not trigger reactive oxygen species, even though neutrophils retained their viability and functional activation potential. Beta-glucans found in the extracellular matrix negatively affected antibiofilm activities. We conclude that these polymers act as a decoy mechanism to prevent neutrophil activation and that this represents an important innate immune evasion mechanism of C. albicans biofilms. PMID:23033146

  1. Stage-specific sampling by pattern recognition receptors during Candida albicans phagocytosis.

    Directory of Open Access Journals (Sweden)

    Sigrid E M Heinsbroek

    2008-11-01

    Full Text Available Candida albicans is a medically important pathogen, and recognition by innate immune cells is critical for its clearance. Although a number of pattern recognition receptors have been shown to be involved in recognition and phagocytosis of this fungus, the relative role of these receptors has not been formally examined. In this paper, we have investigated the contribution of the mannose receptor, Dectin-1, and complement receptor 3; and we have demonstrated that Dectin-1 is the main non-opsonic receptor involved in fungal uptake. However, both Dectin-1 and complement receptor 3 were found to accumulate at the site of uptake, while mannose receptor accumulated on C. albicans phagosomes at later stages. These results suggest a potential role for MR in phagosome sampling; and, accordingly, MR deficiency led to a reduction in TNF-alpha and MCP-1 production in response to C. albicans uptake. Our data suggest that pattern recognition receptors sample the fungal phagosome in a sequential fashion.

  2. Two independent killing mechanisms of Candida albicans by human neutrophils: evidence from innate immunity defects.

    Science.gov (United States)

    Gazendam, Roel P; van Hamme, John L; Tool, Anton T J; van Houdt, Michel; Verkuijlen, Paul J J H; Herbst, Martin; Liese, Johannes G; van de Veerdonk, Frank L; Roos, Dirk; van den Berg, Timo K; Kuijpers, Taco W

    2014-07-24

    Invasive fungal infections, accompanied by high rates of mortality, represent an increasing problem in medicine. Neutrophils are the major effector immune cells in fungal killing. Based on studies with neutrophils from patients with defined genetic defects, we provide evidence that human neutrophils use 2 distinct and independent phagolysosomal mechanisms to kill Candida albicans. The first mechanism for the killing of unopsonized C albicans was found to be dependent on complement receptor 3 (CR3) and the signaling proteins phosphatidylinositol-3-kinase and caspase recruitment domain-containing protein 9 (CARD9), but was independent of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. The second mechanism for the killing of opsonized C albicans was strictly dependent on Fcγ receptors, protein kinase C (PKC), and reactive oxygen species production by the NADPH oxidase system. Each of the 2 pathways of Candida killing required Syk tyrosine kinase activity, but dectin-1 was dispensable for both of them. These data provide an explanation for the variable clinical presentation of fungal infection in patients suffering from different immune defects, including dectin-1 deficiency, CARD9 deficiency, or chronic granulomatous disease. PMID:24948657

  3. Candida albicans PROTEIN PROFILE CHANGES IN RESPONSE TO THE BUTANOLIC EXTRACT OF Sapindus saponariaL.

    Science.gov (United States)

    FIORINI, Adriana; ROSADO, Fabio Rogério; BETTEGA, Eliane Martins da Silva; MELO, Kátia Cristina Sibin; KUKOLJ, Caroline; BONFIM-MENDONÇA, Patrícia de Souza; SHINOBU-MESQUITA, Cristiane Suemi; GHIRALDI, Luciana Dias; CAMPANERUT, Paula Aline Zanetti; CAPOCI, Isis Regina Grenier; GODOY, Janine Silva Ribeiro; FERREIRA, Izabel Cristina Piloto; SVIDZINSKI, Terezinha Inez Estivalet

    2016-01-01

    Candida albicans is an opportunistic human pathogen that is capable of causing superficial and systemic infections in immunocompromised patients. Extracts of Sapindus saponaria have been used as antimicrobial agents against various organisms. In the present study, we used a combination of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) to identify the changes in protein abundance of C. albicans after exposure to the minimal inhibitory concentration (MIC) and sub-minimal inhibitory concentration (sub-MIC) of the butanolic extract (BUTE) of S. saponaria and also to fluconazole. A total of six different proteins with greater than 1.5 fold induction or repression relative to the untreated control cells were identified among the three treatments. In general, proteins/enzymes involved with the glycolysis (GPM1, ENO1, FBA1), amino acid metabolism (ILV5, PDC11) and protein synthesis (ASC1) pathways were detected. In conclusion, our findings reveal antifungal-induced changes in protein abundance of C. albicans. By using the previously identified components of the BUTE of S. saponaria(e.g., saponins and sesquiterpene oligoglycosides), it will be possible to compare the behavior of compounds with unknown mechanisms of action, and this knowledge will help to focus the subsequent biochemical work aimed at defining the effects of these compounds. PMID:27074319

  4. Phenotypic plasticity regulates Candida albicans interactions and virulence in the vertebrate host

    Directory of Open Access Journals (Sweden)

    Emily M Mallick

    2016-05-01

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

  5. Influence of artificial saliva in biofilm formation of Candida albicans in vitro

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    Michelle Peneluppi Silva

    2012-02-01

    Full Text Available Due to the increase in life expectancy, new treatments have emerged which, although palliative, provide individuals with a better quality of life. Artificial saliva is a solution that contains substances that moisten a dry mouth, thus mimicking the role of saliva in lubricating the oral cavity and controlling the existing normal oral microbiota. This study aimed to assess the influence of commercially available artificial saliva on biofilm formation by Candida albicans. Artificial saliva I consists of carboxymethylcellulose, while artificial saliva II is composed of glucose oxidase, lactoferrin, lysozyme and lactoperoxidase. A control group used sterile distilled water. Microorganisms from the oral cavity were transferred to Sabouraud Dextrose Agar and incubated at 37°C for 24 hours. Colonies of Candida albicans were suspended in a sterile solution of NaCl 0.9%, and standardisation of the suspension to 106 cells/mL was achieved. The acrylic discs, immersed in artificial saliva and sterile distilled water, were placed in a 24-well plate containing 2 mL of Sabouraud Dextrose Broth plus 5% sucrose and 0.1 mL aliquot of the Candida albicans suspension. The plates were incubated at 37°C for 5 days, the discs were washed in 2 mL of 0.9% NaCl and placed into a tube containing 10 mL of 0.9% NaCl. After decimal dilutions, aliquots of 0.1 mL were seeded on Sabouraud Dextrose Agar and incubated at 37°C for 48 hours. Counts were reported as CFU/mL (Log10. A statistically significant reduction of 29.89% (1.45 CFU/mL of Candida albicans was observed in saliva I when compared to saliva II (p = 0.002, considering p≤0.05.

  6. COMPARATIVE TRANSCRIPT PROFILING OF Candida albicans AND Candida dubliniensis IDENTIFIES SFL2, A C. albicans GENE REQUIRED FOR VIRULENCE IN A RECONSTITUTED EPITHELIAL INFECTION MODEL

    OpenAIRE

    HIGGINS, JUDY; Sullivan, Derek; Coleman, David; Moran, Gary

    2010-01-01

    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 rapi...

  7. Determinism and probability in the development of the cell theory.

    Science.gov (United States)

    Duchesneau, François

    2012-09-01

    A return to Claude Bernard's original use of the concept of 'determinism' displays the fact that natural laws were presumed to rule over all natural processes. In a more restricted sense, the term boiled down to a mere presupposition of constant determinant causes for those processes, leaving aside any particular ontological principle, even stochastic. The history of the cell theory until around 1900 was dominated by a twofold conception of determinant causes. Along a reductionist trend, cells' structures and processes were supposed to be accounted for through their analysis into detailed partial mechanisms. But a more holistic approach tended to subsume those analytic means and the mechanism involved under a program of global functional determinations. When mitotic and meiotic sequences in nuclear replication were being unveiled and that neo-Mendelian genetics was being grafted onto cytology and embryology, a conception of strict determinism at the nuclear level, principally represented by Wilhelm Roux and August Weismann, would seem to rule unilaterally over the mosaic interpretation of the cleavage of blastomeres. But, as shown by E.B. Wilson, in developmental processes there occur contingent outcomes of cell division which observations and experiments reveal. This induces the need to admit 'epigenetic' determinants and relativize the presumed 'preformation' of thedevelopmental phases by making room for an emergent order which the accidental circumstances of gene replication would trigger on. PMID:22542690

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

    Science.gov (United States)

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

    2015-09-01

    A 4-year-old Turkish girl of consanguineous parents was hospitalized for the evaluation of headaches and recurrent febrile episodes of unknown origin. Her medical history was unremarkable except for a few episodes of uncomplicated oral thrush. Meningitis was diagnosed, and Candida albicans was the only pathogen identified by polymerase chain reaction and culture. Despite systemic antifungal multidrug therapy, a prolonged course of 16 months of therapy was necessary to clear C. albicans from the cerebrospinal fluid. Molecular genetic analysis revealed a homozygous caspase recruitment domain 9 (CARD9) mutation (Q295X), which was reported to predispose to chronic mucocutaneous candidiasis. Immunologic workup excluded predisposing B-cell and T-cell defects. In addition, T cells producing interleukin-17 were repeatedly measured within the normal range. Analyses of neutrophils demonstrated normal nicotinamide adenine dinucleotide phosphate oxidase activity in response to various stimuli including Staphylococcus aureus and C. albicans. Additional neutrophilic functional testing, however, showed a decreased cytotoxicity to nonopsonized C. albicans, indicating an impaired killing mechanism against Candida spp. independent from the production of reactive oxygen species by the nicotinamide adenine dinucleotide phosphate oxidase system. Because this defect was only demonstrated in the absence of opsonins, it might especially predispose to chronic C. albicans infections in the central nervous system where opsonin concentrations are usually low. We, therefore, suggest that due to an additional neutrophil dependent defect CARD9 deficiency predisposes not only to chronic mucocutaneous candidiasis, but also to invasive chronic Candida infections, especially of the central nervous system. PMID:25933095

  9. Dental Caries in Rats Associated with Candida albicans

    OpenAIRE

    Klinke, Thomas; Guggenheim, Bernhard; Klimm, Wolfgang; Thurnheer, Thomas

    2014-01-01

    In addition to occasional opportunistic colonization of the oral mucosa, Candida albicans is frequently found in carious dentin. The yeast’s potential to induce dental caries as a consequence of its pronounced ability to produce and tolerate acids was investigated. Eighty caries-active Osborne-Mendel rats were raised on an ampicillin-supplemented diet and exposed to C. albicans and/or Streptococcus mutans, except for controls. Throughout the 28-day test period, the animals were offered the mo...

  10. Role of extracellular DNA in Candida albicans biofilms

    OpenAIRE

    Martins, Margarida; Henriques, Mariana; Lopez-Ribot, José L.; Oliveira, Rosário

    2009-01-01

    DNA has been described as a structural component of the extracellular matrix in bacterial biofilms. However, in Candida albicans there is a scarce knowledge concerning the contribution of extracellular DNA (ecDNA) to biofilm matrix and overall structure. The main objective of this work was to examine the effect of Deoxyribonuclease I (DNase) treatment and the addition of exogenous DNA on C. albicans biofilm as indicators of the role of ecDNA in biofilm structure and developm...

  11. Biofilm formation among Candida albicans isolated from vagina

    OpenAIRE

    2014-01-01

    Purpose: Study was conducted in a rural tertiary care hospital with a purpose to demonstrate the biofilm forming abilities of C. albicans isolated from cases of vulvovaginal candidiasis and asymptomatic carriers.Material and Methods: C. albicans was isolated and identified by standard laboratory techniques. Biofilm formation in vitro was tested using the 96 well microtitre plate method with crystal violet staining.Results: Overall rate of Candida isolation in study subjects was 40%. Candida i...

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

    OpenAIRE

    Noble, Suzanne

    2013-01-01

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

  13. Virulence factors of non-Candida albicans Candida species

    OpenAIRE

    Silva, Sónia Carina; Negri, M.; Monteiro, D. R.; Henriques, Mariana; Oliveira, Rosário; Azeredo, Joana

    2012-01-01

    Infections caused by Candida species (candidosis) have greatly increased over recent years, mainly due to the escalation of the AIDS epidemic, population ageing, increasing number of immunocompromised patients and the more widespread use of indwelling medical devices. Besides Candida albicans, non-Candida albicans Candida (NCAC) species such as Candida glabrata, Candida tropicalis and Candida parapsilosis are now frequently identified as potential human pathogens. Candida species pathogenicit...

  14. Roles of Candida albicans Sfl1 in Hyphal Development▿

    OpenAIRE

    Li, Yandong; Su, Chang; Mao, Xuming; Cao, Fang; Chen, Jiangye

    2007-01-01

    The ability to switch between different morphological forms is an important feature of Candida albicans and is relevant to its pathogenesis. Many conserved positive and negative transcription factors are involved in morphogenetic regulation of the two dimorphic fungi Candida albicans and Saccharomyces cerevisiae. In S. cerevisiae, the transcriptional repressor Sfl1 and the activator Flo8 function antagonistically in invasive and filamentous growth. We have previously reported that Candida alb...

  15. Ser or Leu: structural snapshots of mistranslation in Candida albicans

    OpenAIRE

    Sárkány, Zsuzsa; Silva, Alexandra; Pereira, Pedro J.B.; Macedo-Ribeiro, Sandra

    2014-01-01

    Candida albicans is a polymorphic opportunistic fungal pathogen normally residing as commensal on mucosal surfaces, skin and gastrointestinal and genitourinary tracts. However, in immunocompromised patients C. albicans can cause superficial mucosal infections or life-threatening disseminated candidemia. A change in physiological conditions triggers a cascade of molecular events leading to morphogenetic alterations and increased resistance to damage induced by host defenses. The complex biolog...

  16. In vitro Antifungal Activity of Cucumis melo on Candida albicans

    OpenAIRE

    Issa Gholampour-Azizi; Samaneh Rouhi; Fahimeh Yahyayi

    2015-01-01

    Background: With respect to the emergence of susceptibility of some fungi to antifungal agents, making use of medicinal plants is progressing. Objectives: The aim of this study was to verify the anti-fungal characteristics of mature and immature Cucumis melo fruit on Candida albicans. Materials and Methods: In this descriptive study, antifungal activity of aqueous, ethnolic and methanolic extracts of C. melo fruits were tested on C. albicans; also results were obtained by disc and well ...

  17. Semiquantitative determination of circulating islet cell surface antibodies in diabetes

    International Nuclear Information System (INIS)

    Circulating pancreatic islet cell antibodies have been demonstrated in patients with insulin-dependent diabetes (IDD). The islet cell surface antibodies (ICSA) were determined by an indirect immunofluorescence test using a suspension of viable islet cells, and similar cytoplasmic antibodies which require the use of group O human pancreas were also found in the serum of some patients. A strong association exists between the presence of islet cell antibodies and the onset of insulin-dependent diabetes. The quantitative determination of circulating ICSA using 125I-protein A, which binds to IgG attached to the islet cell surface, was essentially as described by Lernmark et al. In the present study, we determined the circulating ICSA in diabetes, especially in IDD. The ICSA were estimated in various sera from both indirect immunofluorescence and 125I-protein A. Controls bound 125I-protein A. Sera from 4 IDD patients with circulating ICSA demonstrated by immunofluorescence showed >3,000 cpm 125I-protein A binding activity, and that from 5 patients without ICSA bound <2,000 cpm. Sera from newly-diagnosed diabetics who had severe hyperglycemia showed <2,000 cpm, with or without ICSA. (author)

  18. Galvanic Cells and the Determination of Equilibrium Constants

    Science.gov (United States)

    Brosmer, Jonathan L.; Peters, Dennis G.

    2012-01-01

    Readily assembled mini-galvanic cells can be employed to compare their observed voltages with those predicted from the Nernst equation and to determine solubility products for silver halides and overall formation constants for metal-ammonia complexes. Results obtained by students in both an honors-level first-year course in general chemistry and…

  19. Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin

    Directory of Open Access Journals (Sweden)

    Fernando Augusto Cervantes Garcia de Sousa

    2009-12-01

    Full Text Available The purpose of this study was to evaluate the effect of 5% sodium bicarbonate on the adherence of Candida albicans to thermally activated acrylic resin. Fifty 4 mm² specimens of acrylic resin were obtained using a metallic matrix. The specimens received chemical polishing, were sterilized and then immersed in Sabouraud broth, inoculated with Candida albicans standardized suspension. After 24 hours of incubation at 37ºC, the specimens were divided into four groups according to the substance used for disinfection (5% sodium bicarbonate, 0.12% digluconate chlorhexidine, vinegar and Corega Tabs. A control group was included, in which distilled water was used. The adhered microorganisms were dispersed, diluted and plated onto culture media to determine the number of colony-forming units (cfu/mL. The results were analyzed through the Mann-Whitney statistical test at the 5% level of significance. Only 0.12% digluconate chlorhexidine and 5% sodium bicarbonate presented a statistically significant difference (p = 0.0010 and p = 0.0156, respectively compared to the control group, decreasing the number of cfu/mL. However, when the different disinfecting solutions were compared with each other, only 0.12% digluconate chlorhexidine presented a statistically significant difference in the reduction of cfu/mL. It was concluded that although 0.12% digluconate chlorhexidine was more effective in the reduction of Candida albicans adherence values to thermally activated acrylic resin, 5% sodium bicarbonate also proved to be a viable alternative.

  20. Roles of Edc3 in the oxidative stress response and CaMCA1-encoded metacaspase expression in Candida albicans.

    Science.gov (United States)

    Jung, Jong-Hwan; Kim, Jinmi

    2014-11-01

    The Edc3 protein is an enhancer of mRNA decapping, and acts as a scaffold protein for the mRNA granules that are known as processing bodies in yeast. In the pathogenic yeast Candida albicans, various stresses, such as glucose depletion, oxidative stress, and filamentation defects, induce the accumulation of processing bodies. Here, we report that the edc3/edc3 deletion strain showed increased resistance to various stresses, including hydrogen peroxide, acetic acid, and high temperature. Oxidative stress is known to induce the intracellular accumulation of reactive oxygen species (ROS) and apoptotic cell death in C. albicans. We found that the ROS level was lower in edc3/edc3 cells than in wild-type cells following oxidative stress. We also observed that expression of the metacaspase gene CaMCA1 was decreased in edc3/edc3 cells. Overexpression of CaMCA1 suppressed the decreased accumulation of ROS and the increased resistance to hydrogen peroxide in edc3/edc3 cells. The catalase Cat1 and the superoxide dismutase Sod1 were upregulated in edc3/edc3 cells as compared with wild-type cells. On the basis of these findings, we suggest that EDC3 plays a critical role in the expression of CaMCA1 and the oxidative stress response in C. albicans. PMID:25158786

  1. Inhibiting the immunoproteasome exacerbates the pathogenesis of systemic Candida albicans infection in mice

    OpenAIRE

    Sarah Mundt; Michael Basler; Stefanie Buerger; Harald Engler; Marcus Groettrup

    2016-01-01

    Apart from its role in MHC class I antigen processing, the immunoproteasome has recently been implicated in the modulation of T helper cell differentiation under polarizing conditions in vitro and in the pathogenesis of autoimmune diseases in vivo. In this study, we investigated the influence of LMP7 on T helper cell differentiation in response to the fungus Candida albicans. We observed a strong effect of ONX 0914, an LMP7-selective inhibitor of the immunoproteasome, on IFN-γ and IL-17A prod...

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

    Science.gov (United States)

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

    2016-02-01

    Resistance to azole antifungals is a significant problem in Candida albicans. An understanding of resistance at molecular level is essential for the development of strategies to tackle resistance and rationale design of newer antifungals and target-based molecular approaches. This study presents the first evaluation of molecular mechanisms associated with fluconazole resistance in clinical C.albicans isolates from India. Target site (ERG11) alterations were determined by DNA sequencing, whereas real-time PCRs were performed to quantify target and efflux pump genes (CDR1, CDR2, MDR1) in 87 [Fluconazole susceptible (n = 30), susceptible-dose dependent (n = 30) and resistant (n = 27)] C.albicans isolates. Cross-resistance to fluconazole, ketoconazole and itraconazole was observed in 74.1% isolates. Six amino acid substitutions were identified, including 4 (E116D, F145L, E226D, I437V) previously reported ones and 2 (P406L, Q474H) new ones. CDR1 over-expression was seen in 77.7% resistant isolates. CDR2 was exclusively expressed with CDR1 and their concomitant over-expression was associated with azole cross-resistance. MDR1 and ERG11 over-expression did not seem to be associated with resistance. Our results show that drug efflux mediated by Adenosine-5'-triphosphate (ATP)-binding cassette transporters, especially CDR1 is the predominant mechanism of fluconazole resistance and azole cross-resistance in C. albicans and indicate the need for research directed towards developing strategies to tackle efflux mediated resistance to salvage azoles. PMID:26648048

  3. Direct determination of phosphatase activity from physiological substrates in cells.

    Directory of Open Access Journals (Sweden)

    Zhongyuan Ren

    Full Text Available A direct and continuous approach to determine simultaneously protein and phosphate concentrations in cells and kinetics of phosphate release from physiological substrates by cells without any labeling has been developed. Among the enzymes having a phosphatase activity, tissue non-specific alkaline phosphatase (TNAP performs indispensable, multiple functions in humans. It is expressed in numerous tissues with high levels detected in bones, liver and neurons. It is absolutely required for bone mineralization and also necessary for neurotransmitter synthesis. We provided the proof of concept that infrared spectroscopy is a reliable assay to determine a phosphatase activity in the osteoblasts. For the first time, an overall specific phosphatase activity in cells was determined in a single step by measuring simultaneously protein and substrate concentrations. We found specific activities in osteoblast like cells amounting to 116 ± 13 nmol min(-1 mg(-1 for PPi, to 56 ± 11 nmol min(-1 mg(-1 for AMP, to 79 ± 23 nmol min(-1 mg(-1 for beta-glycerophosphate and to 73 ± 15 nmol min(-1 mg(-1 for 1-alpha-D glucose phosphate. The assay was also effective to monitor phosphatase activity in primary osteoblasts and in matrix vesicles. The use of levamisole--a TNAP inhibitor--served to demonstrate that a part of the phosphatase activity originated from this enzyme. An IC50 value of 1.16 ± 0.03 mM was obtained for the inhibition of phosphatase activity of levamisole in osteoblast like cells. The infrared assay could be extended to determine any type of phosphatase activity in other cells. It may serve as a metabolomic tool to monitor an overall phosphatase activity including acid phosphatases or other related enzymes.

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

    Directory of Open Access Journals (Sweden)

    Gilbert Ian

    2011-01-01

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

  5. Fast and accurate automated cell boundary determination for fluorescence microscopy

    Science.gov (United States)

    Arce, Stephen Hugo; Wu, Pei-Hsun; Tseng, Yiider

    2013-07-01

    Detailed measurement of cell phenotype information from digital fluorescence images has the potential to greatly advance biomedicine in various disciplines such as patient diagnostics or drug screening. Yet, the complexity of cell conformations presents a major barrier preventing effective determination of cell boundaries, and introduces measurement error that propagates throughout subsequent assessment of cellular parameters and statistical analysis. State-of-the-art image segmentation techniques that require user-interaction, prolonged computation time and specialized training cannot adequately provide the support for high content platforms, which often sacrifice resolution to foster the speedy collection of massive amounts of cellular data. This work introduces a strategy that allows us to rapidly obtain accurate cell boundaries from digital fluorescent images in an automated format. Hence, this new method has broad applicability to promote biotechnology.

  6. Neutrophils influx and proinflammatory cytokines inhibition by sodium salicylate, unlike aspirin, in Candida albicans-induced peritonitis model.

    Science.gov (United States)

    Pereira, Priscilla Aparecida Tártari; Bini, Daniel; Bovo, Fernanda; Faccioli, Lucia Helena; Monteiro, Marta Chagas

    2016-07-01

    Sodium salicylate (NaS) and aspirin (ASA) are known to have a variety of effects on microorganisms, such as fungus (C. albicans and C. neoformans), moreover, it have effects in leukocyte adhesion and migration in vitro. In this report, we investigated the effect of ASA and NaS in neutrophil migration and cytokine production in C. albicans-induced peritonitis murine model. For this, mice were treated intraperitoneally (i.p) or orally (po) with NaS or ASA; after they were stimulated i.p. with C. albicans, the cellular migration was evaluated 24 h after stimulation. NaS, in mice treated i.p., unlike ASA, was able to inhibit the neutrophil migration and proinflammatory cytokine production induced by C. albicans, such as TNF-α, IL-1, IFN-γ, IL-12, and IL-10, but did not alter the IL-4 levels in these animals. However, the po treatment with same the dose of NaS or ASA did not affect the influx of this cell for inflammatory site. These results suggest that the NaS inhibits cellular migration and proinflammatory cytokine by different anti-inflammatory mechanism compared to ASA. PMID:26762336

  7. Determining Cell Number During Cell Culture using the Scepter Cell Counter

    OpenAIRE

    Ongena, Kathleen; Das, Chandreyee; Smith, Janet L.; Gil, Sónia; Johnston, Grace

    2010-01-01

    Counting cells is often a necessary but tedious step for in vitro cell culture. Consistent cell concentrations ensure experimental reproducibility and accuracy. Cell counts are important for monitoring cell health and proliferation rate, assessing immortalization or transformation, seeding cells for subsequent experiments, transfection or infection, and preparing for cell-based assays. It is important that cell counts be accurate, consistent, and fast, particularly for quantitative measuremen...

  8. Candida albicans biofilms and MMA surface treatment influence the adhesion of soft denture liners to PMMA resin

    Directory of Open Access Journals (Sweden)

    Martinna de Mendonça e Bertolini

    2014-01-01

    Full Text Available The effect of Candida albicans biofilms and methyl methacrylate (MMA pretreatment on the bond strength between soft denture liners and polymethyl methacrylate (PMMA resin was analyzed. Specimens were prepared and randomly divided with respect to PMMA pretreatment, soft liner type (silicone-based or PMMA-based, and presence or absence of a C. albicans biofilm. Samples were composed of a soft denture liner bonded between two PMMA bars. Specimens (n = 10 were incubated to produce a C. albicans biofilm or stored in sterile PBS for 12 days. The tensile bond strength test was performed and failure type was determined using a stereomicroscope. Surface roughness (SR and scanning electron microscopy (SEM analysis were performed on denture liners (n = 8. Highest bond strength was observed in samples containing a silicone-based soft liner and stored in PBS, regardless of pretreatment (p < 0.01. Silicone-based specimens mostly underwent adhesive failures, while samples containing PMMA-based liners predominantly underwent cohesive failures. The silicone-based specimens SR decreased after 12 days of biofilm accumulation or PBS storage, while the SR of PMMA-based soft liners increased (p < 0.01. The PMMA-based soft liners surfaces presented sharp valleys and depressions, while silicone-based specimens surfaces exhibited more gentle features. In vitro exposure to C. albicans biofilms reduced the adhesion of denture liners to PMMA resin, and MMA pretreatment is recommended during relining procedures.

  9. Reduced folate carrier polymorphism determines methotrexate uptake by B cells and CD4+ T cellsTumor necrosis factor-alpha binding capacity and anti-infliximab antibodies measured by fluid-phase radioimmunoassays as predictors of clinical efficacy of infliximab in Crohn's disease

    DEFF Research Database (Denmark)

    Baslund, B.; Gregers, J.; Nielsen, Claus Henrik

    2008-01-01

    cells stimulated with Candida albicans or tetanus toxoid, and the uptake of MTX was measured by flow cytometry. A FITC-conjugated monoclonal antibody against RFC was used to detect the cellular RFC expression. RESULTS: Antigen-stimulated CD4+ T cells and B cells from individuals with the GG variant (n...

  10. Determination of cell volume during equilibrium freezing process

    Institute of Scientific and Technical Information of China (English)

    ZHAO Gang; GAO Dayong; HE Liqun; WANG Peitao; DING Weiping; XIE Xiaojian; LIU Zhong; ZHANG Haifeng; SHU Zhiquan; LUO Dawei

    2003-01-01

    A new type electronic particle counter (EPC, MultisizerTM 3, Beckman Coulter Inc., USA) was used to determine the volumes of human red blood cells (RBCs) in NaCl solutions of different osmolalities. The thermodynamics model describing cell response during freezing process was used to simulate the volume change of RBC in 0.9% NaCl solution during equilibrium freezing process. It was assumed that the effect of temperature on cell volume can be neglected compared to that of osmolality, then by using the phase diagram for the binary system sodium chloride/water, the osmolalities of the NaCl solution under different sub-zero temperatures can be obtained (converted from mass concentration), then the calculated values of RBC volumes can be validated by the experiments.

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

    Science.gov (United States)

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

    2012-04-01

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

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

    Science.gov (United States)

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

    2015-11-01

    As a successful commensal and pathogen of humans, Candida albicans encounters a wide range of environmental conditions. Among them, ambient pH, which changes frequently and affects many biological processes in this species, is an important factor, and the ability to adapt to pH changes is tightly linked with pathogenesis and morphogenesis. In this study, we report that pH has a profound effect on white-opaque switching and sexual mating in C. albicans. Acidic pH promotes white-to-opaque switching under certain culture conditions but represses sexual mating. The Rim101-mediated pH-sensing pathway is involved in the control of pH-regulated white-opaque switching and the mating response. Phr2 and Rim101 could play a major role in acidic pH-induced opaque cell formation. Despite the fact that the cyclic AMP (cAMP) signaling pathway does not play a major role in pH-regulated white-opaque switching and mating, white and opaque cells of the cyr1/cyr1 mutant, which is defective in the production of cAMP, showed distinct growth defects under acidic and alkaline conditions. We further discovered that acidic pH conditions repressed sexual mating due to the failure of activation of the Ste2-mediated α-pheromone response pathway in opaque A: cells. The effects of pH changes on phenotypic switching and sexual mating could involve a balance of host adaptation and sexual reproduction in C. albicans. PMID:26342021

  13. Neonatal malnutrition programs the oxidant function of macrophages in response to Candida albicans.

    Science.gov (United States)

    Costa, Thacianna Barreto Da; Morais, Natália Gomes De; Pedrosa, Amanda Lúcia F; De Albuquerque, Suênia Da Cunha G; De Castro, Maria Carolina A B; Pereira, Valéria Rêgo A; Cavalcanti, Milena De Paiva; De Castro, Célia Maria M B

    2016-06-01

    Experimental maternal nutrition restriction models are used to investigate short or long-term consequences of nutritional deficiency on puppies' growth. By assuming that the immune function is directly related to host's nutritional status, the current study aims to investigate the effects of neonatal malnutrition on oxidative stress and on the cell death of the alveolar macrophage after in vitro infection by Candida albicans. Wistar rats were suckled by mothers fed on diets containing 17% protein (Nourished group) or 8% protein (Malnourished group) in the current assay. Both groups received the standard diet used in the vivarium until adulthood, after weaning. The results showed that the offspring from mothers fed on low-protein diet presented lower body weight from 5 days of life on. Their low weight remained until adulthood when it was compared to that of rats in the nourished group. Superoxide and nitric oxide production was lower in malnourished animals and it was accompanied by low inducible nitric oxide synthase gene expression levels in systems in which the alveolar macrophages were challenged by immunogenic stimulus. No significant differences were observed in comparisons performed between the nourished and malnourished groups in any of the analyzed cell viability (apoptosis/necrosis) parameters. The fungal inoculum-stimulated system induced higher oxidative stress and cell death by necrosis. The current study demonstrated that dietary restriction during lactation alters the oxidant function of alveolar macrophages in puppies; It happens from the gene transcription step to the release of mediators, thus compromising the host's defenses against Candida albicans. It raises the possibility that Candida albicans may cease to be a commensal fungus to become a pathogen in offspring that have suffered nutritional deficiency during critical developmental periods, due to impaired immune responses. PMID:27001703

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Science.gov (United States)

    Roudbarmohammadi, Shahla; Roudbary, Maryam; Bakhshi, Bita; Katiraee, Farzad; Mohammadi, Rasoul; Falahati, Mehraban

    2016-01-01

    Background: A cluster of genes are involved in the pathogenesis and adhesion of Candida albicans to mucosa and epithelial cells in the vagina, the important of which is agglutinin-like sequence (ALS) genes. As well as vaginitis is a significant health problem among women, the antifungal resistance of Candida species is continually increasing. This cross-sectional study investigates the expression of ALS1 and ALS3 genes and biofilm formation in C. albicans isolate isolated from vaginitis. Materials and Methods: Fifty-three recognized isolates of C. albicans were collected from women with recurrent vulvovaginal candidiasis in Iran, cultured on sabouraud dextrose agar, and then examined for gene expression. Total messenger RNA (mRNA) extracted from C. albicans isolates and complementary DNA synthesized using reverse transcriptase enzyme. Reverse transcription-polymerase chain reaction (RT-PCR) using specific primer was used to evaluate the expression of ALS1 and ALS3 through housekeeping (ACT1) genes. 3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide assay was performed to assess adherence capacity and biofilm formation in the isolated. Results: Forty isolates (75.8%) expressed ALS1 and 41 isolates (77.7%) expressed ALS3 gene. Moreover, 39 isolates (74%) were positive for both ALS1 and ALS3 mRNA by the RT-PCR. Adherence capability in isolates with ALS1 or ALS3 genes expression was greater than the control group (with any gene expression), besides, it was significantly for the most in the isolates that expressed both ALS1 and ALS3 genes simultaneously. Conclusion: The results attained indicated that there is an association between the expression of ALS1 and ALS3 genes and fluconazole resistance in C. albicans. A considerable percent of the isolates expressing the ALS1 and ALS3 genes may have contributed to their adherence to vagina and biofilm formation. PMID:27376044

  16. Candida albicans ethanol stimulates Pseudomonas aeruginosa WspR-controlled biofilm formation as part of a cyclic relationship involving phenazines.

    Directory of Open Access Journals (Sweden)

    Annie I Chen

    2014-10-01

    Full Text Available In chronic infections, pathogens are often in the presence of other microbial species. For example, Pseudomonas aeruginosa is a common and detrimental lung pathogen in individuals with cystic fibrosis (CF and co-infections with Candida albicans are common. Here, we show that P. aeruginosa biofilm formation and phenazine production were strongly influenced by ethanol produced by the fungus C. albicans. Ethanol stimulated phenotypes that are indicative of increased levels of cyclic-di-GMP (c-di-GMP, and levels of c-di-GMP were 2-fold higher in the presence of ethanol. Through a genetic screen, we found that the diguanylate cyclase WspR was required for ethanol stimulation of c-di-GMP. Multiple lines of evidence indicate that ethanol stimulates WspR signaling through its cognate sensor WspA, and promotes WspR-dependent activation of Pel exopolysaccharide production, which contributes to biofilm maturation. We also found that ethanol stimulation of WspR promoted P. aeruginosa colonization of CF airway epithelial cells. P. aeruginosa production of phenazines occurs both in the CF lung and in culture, and phenazines enhance ethanol production by C. albicans. Using a C. albicans adh1/adh1 mutant with decreased ethanol production, we found that fungal ethanol strongly altered the spectrum of P. aeruginosa phenazines in favor of those that are most effective against fungi. Thus, a feedback cycle comprised of ethanol and phenazines drives this polymicrobial interaction, and these relationships may provide insight into why co-infection with both P. aeruginosa and C. albicans has been associated with worse outcomes in cystic fibrosis.

  17. Determination of telomerase activity in stem cells and non-stem cells of breast cancer

    Institute of Scientific and Technical Information of China (English)

    LI Zhi; HE Yanli; ZHANG Jiahua; ZHANG Jinghui; HUANG Tao

    2007-01-01

    Although all normal tissue cells,including stem cells,are genetically homologous,variation in gene expression patterns has already determined the distinct roles for individual cells in the physiological process due to the occurrence of epigenetic modification.This is of special importance for the existenee of tissue stem cells because they are exclusively immortal within the body,capable of selfreplicating and differentiating by which tissues renew and repair itself and the total tissue cell population maintains a steady-state.Impairment of tissue stem cells is usually accompanied by a reduction in cell number,slows down the repair process and causes hypofunction.For instance,chemotherapy usually leads to depression of bone marrow and hair loss.Cellular aging is closely associated with the continuous erosion of the telomere while activation of telomerase repairs and maintains telomeres,thus slowing the aging process and prolonging cell life.In normal adults,telomerase activation mainly presents in tissue stem cells and progenitor cells giving them unlimited growth potential.Despite the extensive demonstration of telomerase activation in malignancy(>80%),scientists found that heterogeneity also exists among the tumor cells and only minorities of cells,designated as cancer stem cells,andergo processes analogous to the self-renewal and differentiation of normal stem ceils while the rest have limited lifespans.In this study,telomerase activity was measured and compared in breast cancer stem cells and non-stem cells that were phenotypically sorted by examining surface marker expression.The results indicated that cancer stem cells show a higher level of enzyme activity than non-stem cells.In addition,associated with the repair of cancer tissue(or relapse)after chemotherapy,telomerase activity in stem cells was markedly increased.

  18. Electrophoretic protein patterns and numerical analysis of Candida albicans from the oral cavities of healthy children

    Directory of Open Access Journals (Sweden)

    Boriollo Marcelo Fabiano Gomes

    2003-01-01

    Full Text Available The aim of this research was to evaluate the protein polymorphism degree among seventy-five C. albicans strains from healthy children oral cavities of five socioeconomic categories from eight schools (private and public in Piracicaba city, São Paulo State, in order to identify C. albicans subspecies and their similarities in infantile population groups and to establish their possible dissemination route. Cell cultures were grown in YEPD medium, collected by centrifugation, and washed with cold saline solution. The whole-cell proteins were extracted by cell disruption, using glass beads and submitted to SDS-PAGE technique. After electrophoresis, the protein bands were stained with Coomassie-blue and analyzed by statistics package NTSYS-pc version 1.70 software. Similarity matrix and dendrogram were generated by using the Dice similarity coefficient and UPGMA algorithm, respectively, which made it possible to evaluate the similarity or intra-specific polymorphism degrees, based on whole-cell protein fingerprinting of C. albicans oral isolates. A total of 13 major phenons (clusters were analyzed, according to their homogeneous (socioeconomic category and/or same school and heterogeneous (distinct socioeconomic categories and/or schools characteristics. Regarding to the social epidemiological aspect, the cluster composition showed higher similarities (0.788 < S D < 1.0 among C. albicans strains isolated from healthy children independent of their socioeconomic bases (high, medium, or low. Isolates of high similarity were not found in oral cavities from healthy children of social stratum A and D, B and D, or C and E. This may be explained by an absence of a dissemination route among these children. Geographically, some healthy children among identical and different schools (private and public also are carriers of similar strains but such similarity was not found among other isolates from children from certain schools. These data may reflect a

  19. Iron-Limited Biofilms of Candida albicans and Their Susceptibility to Amphotericin B

    OpenAIRE

    Baillie, George S.; Douglas, L. Julia

    1998-01-01

    Biofilms of Candida albicans were grown in vitro under iron limitation and at a low growth rate to simulate conditions for implant-associated biofilms in vivo. Their properties were compared with those of glucose-limited biofilms grown under analogous conditions. At steady state, the adherent cell populations of iron-limited biofilms were double those of glucose-limited biofilms, although the growth rates were similar (0.038 to 0.043 h−1). Both biofilm types were resistant to amphotericin B, ...

  20. Morphogenesis of Candida albicans and Cytoplasmic Proteins Associated with Differences in Morphology, Strain, or Temperature

    OpenAIRE

    1981-01-01

    The extent of change in cytoplasmic proteins which accompanies yeast-to-mycelium morphogenesis of Candida albicans was analyzed by two-dimensional gel electrophoresis. Pure cultures of yeasts and true hyphae (i.e., without concomitant production of pseudohyphae) were grown in a synthetic low-sulfate medium. The two strains selected for this study were strain 4918, which produces pure mycelial cultures in low-sulfate medium at 37 degrees C and yeast cells at 24 degrees C, and strain 2252, whic...

  1. Impact of Low Frequency Electromagnetic Field Exposure on the Candida Albicans

    Science.gov (United States)

    Malíková, Ivona; Janoušek, Ladislav; Fantova, Vladyslava; Jíra, Jaroslav; Kříha, Vítĕzslav

    2015-03-01

    Effect of low frequency electromagnetic field on growth of selected microorganism is studied in the article. The diploid fungus that grows both as yeast and filamentous cell was chosen for this research. The theory of ion parametric resonance was taken as the base for studying the influence of electromagnetic field on biological structures. We tested the hypothesis, whether it is possible to observe the change in growth properties of Candida albicans with an AC electromagnetic field tuned to resonance with calcium ions cyclotron frequency.

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

    Directory of Open Access Journals (Sweden)

    Pedro Miramón

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

  3. Liquid and vapour-phase antifungal activities of selected essential oils against candida albicans: microscopic observations and chemical characterization of cymbopogon citratus

    OpenAIRE

    Malik Anushree; Tyagi Amit K

    2010-01-01

    Abstract Background Use of essential oils for controlling Candida albicans growth has gained significance due to the resistance acquired by pathogens towards a number of widely-used drugs. The aim of this study was to test the antifungal activity of selected essential oils against Candida albicans in liquid and vapour phase and to determine the chemical composition and mechanism of action of most potent essential oil. Methods Minimum Inhibitory concentration (MIC) of different essential oils ...

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

    OpenAIRE

    Ria Puspitawati; Theodorus Hedwin Kadrianto; Bachtiar, Boy M.; Lakshmi A. Leepel

    2013-01-01

    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 f...

  5. The role of faecal Candida albicans in the pathogenesis of food-intolerant irritable bowel syndrome.

    OpenAIRE

    Middleton, S J; Coley, A.; Hunter, J O

    1992-01-01

    Candida albicans was sought in stool samples from 38 patients with irritable bowel syndrome and 20 healthy controls. In only three patients with irritable bowel syndrome was C. albicans discovered and these patients had either recently received antibiotics or the stool sample had been delayed more than 24 hours in transit. C. albicans was isolated from none of the control stool samples. We conclude that C. albicans is not involved in the aetiology of the irritable bowel syndrome.

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

    OpenAIRE

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

    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 ...

  7. Determination of in vitro oxygen consumption rates for tumor cells

    International Nuclear Information System (INIS)

    To determine pO2 at the surface of a monolayer of confluent HCT 116 cells, and to then determine consumption rate in vitro by examining the pO2 profile in media above the cells. Materials and Methods: A recessed-tip polarographic oxygen microelectrode (diameter ∼10μm) was used to measure pO2 profiles of media above a confluent monolayer of HCT 116 human colon adenocarcinoma cells in a T25 flask exposed to a 95% air, 5% CO2 mixture. A two-dimensional finite element analysis of the diffusion equation was used to fit the data, thereby extracting a steady-state O2 consumption rate. The diffusion equation was solved for zeroth and first-order expressions. No-flux boundary conditions were imposed on its bottom and side boundaries and experimental data was used for boundary conditions at the gas-media boundary. All flasks show an O2 gradient in the media, with a mean (SE) media layer of 1677 (147) μm and a mean pO2 at the cell layer/media interface of 44 (8) mm Hg (n=9). pO2 gradient over the entire media layer is 630 (90) mm Hg/cm, equivalent to a consumption rate of 6.3 x 10-4 (9.0 x 10-5) mm Hg/s. The mean values for the zeroth and first order rate constants are 8.1 x 10-9(1.3 x 10-9) g mol O2/cm3s and 1.0 x 103(0.46 x 103) /s, respectively. Control experiments in flasks containing no cells show slight gradients in pO2 of 38 (12) mm Hg/cm, resulting from some O2 diffusion through the flask into the surrounding water bath. An addition of 10-3M NaCN to the media results in a dramatic increase in pO2 at the cell layer, consistent with a shut-down in respiration. Under normal cell culture conditions there is an O2 gradient present in the media of cull culture systems, resulting in physiologic O2 concentrations at the cell layer, despite the non-physiologic O2 concentration of the gas mixture to which the cell culture system is exposed. This significant (p-6) O2 gradient in the media of cell culture systems is a result of cell O2 consumption and should be considered in

  8. Farnesol-induced apoptosis in Candida albicans is mediated by Cdr1-p extrusion and depletion of intracellular glutathione.

    Science.gov (United States)

    Zhu, Jingsong; Krom, Bastiaan P; Sanglard, Dominique; Intapa, Chaidan; Dawson, Clinton C; Peters, Brian M; Shirtliff, Mark E; Jabra-Rizk, Mary Ann

    2011-01-01

    Farnesol is a key derivative in the sterol biosynthesis pathway in eukaryotic cells previously identified as a quorum sensing molecule in the human fungal pathogen Candida albicans. Recently, we demonstrated that above threshold concentrations, farnesol is capable of triggering apoptosis in C. albicans. However, the exact mechanism of farnesol cytotoxicity is not fully elucidated. Lipophilic compounds such as farnesol are known to conjugate with glutathione, an antioxidant crucial for cellular detoxification against damaging compounds. Glutathione conjugates act as substrates for ATP-dependent ABC transporters and are extruded from the cell. To that end, this current study was undertaken to validate the hypothesis that farnesol conjugation with intracellular glutathione coupled with Cdr1p-mediated extrusion of glutathione conjugates, results in total glutathione depletion, oxidative stress and ultimately fungal cell death. The combined findings demonstrated a significant decrease in intracellular glutathione levels concomitant with up-regulation of CDR1 and decreased cell viability. However, addition of exogenous reduced glutathione maintained intracellular glutathione levels and enhanced viability. In contrast, farnesol toxicity was decreased in a mutant lacking CDR1, whereas it was increased in a CDR1-overexpressing strain. Further, gene expression studies demonstrated significant up-regulation of the SOD genes, primary enzymes responsible for defense against oxidative stress, with no changes in expression in CDR1. This is the first study describing the involvement of Cdr1p-mediated glutathione efflux as a mechanism preceding the farnesol-induced apoptotic process in C. albicans. Understanding of the mechanisms underlying farnesol-cytotoxicity in C. albicans may lead to the development of this redox-cycling agent as an alternative antifungal agent. PMID:22205973

  9. Farnesol-induced apoptosis in Candida albicans is mediated by Cdr1-p extrusion and depletion of intracellular glutathione.

    Directory of Open Access Journals (Sweden)

    Jingsong Zhu

    Full Text Available Farnesol is a key derivative in the sterol biosynthesis pathway in eukaryotic cells previously identified as a quorum sensing molecule in the human fungal pathogen Candida albicans. Recently, we demonstrated that above threshold concentrations, farnesol is capable of triggering apoptosis in C. albicans. However, the exact mechanism of farnesol cytotoxicity is not fully elucidated. Lipophilic compounds such as farnesol are known to conjugate with glutathione, an antioxidant crucial for cellular detoxification against damaging compounds. Glutathione conjugates act as substrates for ATP-dependent ABC transporters and are extruded from the cell. To that end, this current study was undertaken to validate the hypothesis that farnesol conjugation with intracellular glutathione coupled with Cdr1p-mediated extrusion of glutathione conjugates, results in total glutathione depletion, oxidative stress and ultimately fungal cell death. The combined findings demonstrated a significant decrease in intracellular glutathione levels concomitant with up-regulation of CDR1 and decreased cell viability. However, addition of exogenous reduced glutathione maintained intracellular glutathione levels and enhanced viability. In contrast, farnesol toxicity was decreased in a mutant lacking CDR1, whereas it was increased in a CDR1-overexpressing strain. Further, gene expression studies demonstrated significant up-regulation of the SOD genes, primary enzymes responsible for defense against oxidative stress, with no changes in expression in CDR1. This is the first study describing the involvement of Cdr1p-mediated glutathione efflux as a mechanism preceding the farnesol-induced apoptotic process in C. albicans. Understanding of the mechanisms underlying farnesol-cytotoxicity in C. albicans may lead to the development of this redox-cycling agent as an alternative antifungal agent.

  10. The adaptor CARD9 is required for adaptive but not innate immunity to oral mucosal Candida albicans infections.

    Science.gov (United States)

    Bishu, Shrinivas; Hernández-Santos, Nydiaris; Simpson-Abelson, Michelle R; Huppler, Anna R; Conti, Heather R; Ghilardi, Nico; Mamo, Anna J; Gaffen, Sarah L

    2014-03-01

    Oropharyngeal candidiasis (OPC [thrush]) is an opportunistic infection caused by the commensal fungus Candida albicans. OPC is common in individuals with HIV/AIDS, infants, patients on chemotherapy, and individuals with congenital immune defects. Immunity to OPC is strongly dependent on the interleukin-23 (IL-23)/IL-17R axis, as mice and humans with defects in IL-17R signaling (IL17F, ACT1, IL-17RA) or in genes that direct Th17 differentiation (STAT3, STAT1, CARD9) are prone to mucocutaneous candidiasis. Conventional Th17 cells are induced in response to C. albicans infection via signals from C-type lectin receptors, which signal through the adaptor CARD9, leading to production of Th17-inducing cytokines such as IL-6, IL-1β, and IL-23. Recent data indicate that IL-17 can also be made by numerous innate cell subsets. These innate "type 17" cells resemble conventional Th17 cells, but they can be activated without need for prior antigen exposure. Because C. albicans is not a commensal organism in rodents and mice are thus naive to this fungus, we had the opportunity to assess the role of CARD9 in innate versus adaptive responses using an OPC infection model. As expected, CARD9(-/-) mice failed to mount an adaptive Th17 response following oral Candida infection. Surprisingly, however, CARD9(-/-) mice had preserved innate IL-17-dependent responses to Candida and were almost fully resistant to OPC. Thus, CARD9 is important primarily for adaptive immunity to C. albicans, whereas alternate recognition systems appear to be needed for effective innate responses. PMID:24379290

  11. Role of Geminin in cell fate determination of hematopoietic stem cells (HSCs).

    Science.gov (United States)

    Yasunaga, Shin'ichiro; Ohno, Yoshinori; Shirasu, Naoto; Zhang, Bo; Suzuki-Takedachi, Kyoko; Ohtsubo, Motoaki; Takihara, Yoshihiro

    2016-09-01

    Geminin exerts two distinct molecular roles. Geminin negatively regulates DNA replication licensing through the direct interaction with Cdt1 to prevent re-replication in proliferating cells. Geminin also regulates chromatin remodeling through the direct interaction with Brahma/Brg1 to maintain undifferentiated states of stem cells. We previously uncovered that Polycomb-group complex 1 and Hoxb4/Hoxa9, well-known intrinsic factors that are essential for maintaining the hematopoietic stem cell (HSC) activity, alternatively act as ubiquitin-proteasome systems for Geminin protein to reduce the protein expression level, and sustain the HSC activity. Thus, Geminin is presumed to play an important role in determining cell fate, i.e., turning on and off cellular quiescence and proliferation/differentiation, in HSCs. We recently generated recombinant cell-penetrating Geminin (CP-Geminin), enabling rapid incorporation and withdraw of Geminin protein in cells. CP-Geminin may be useful in regulating the cell cycle and chromatin configuration. In this article, we summarize current information on the molecular functions of Geminin and the regulatory system for Geminin protein expression, and argue for the molecular role of Geminin in cell fate determination of HSCs, and future perspective of a new technology for manipulating the activities of HSCs and cancer stem cells (CSCs). PMID:27422432

  12. White-Opaque Switching in Natural MTLa/α Isolates of Candida albicans: Evolutionary Implications for Roles in Host Adaptation, Pathogenesis, and Sex

    OpenAIRE

    Xie, J.; L. Tao; Nobile, CJ; Tong, Y; Guan, G; Sun, Y; Cao, C.; Hernday, AD; Johnson, AD; L. Zhang; Bai, FY; Huang, G.

    2013-01-01

    Phenotypic transitions play critical roles in host adaptation, virulence, and sexual reproduction in pathogenic fungi. A minority of natural isolates of Candida albicans, which are homozygous at the mating type locus (MTL, a/a or α/α), are known to be able to switch between two distinct cell types: white and opaque. It is puzzling that white-opaque switching has never been observed in the majority of natural C. albicans strains that have heterozygous MTL genotypes (a/α), given that they conta...

  13. Candida albicans and Candida stellatoidea, in contrast to other Candida species, bind iC3b and C3d but not C3b.

    OpenAIRE

    Heidenreich, F; Dierich, M.P.

    1985-01-01

    It was demonstrated that complement-coated sheep erythrocytes bind to Candida albicans cells grown in serum-free RPMI 1640 medium. Testing of purified complement components proved that iC3b and C3d were responsible for the reaction, whereas C3b and C3b-H reacted only slightly if at all. Binding occurred only to C. albicans and C. stellatoidea, not to other species pathogenic to humans. There was evidence of a lectinlike nature of the effect.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Diana M Calderón-Noreña

    2015-04-01

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

  16. Diorcinol D Exerts Fungicidal Action against Candida albicans through Cytoplasm Membrane Destruction and ROS Accumulation.

    Science.gov (United States)

    Li, Ying; Chang, Wenqiang; Zhang, Ming; Li, Xiaobin; Jiao, Yang; Lou, Hongxiang

    2015-01-01

    Candida albicans, which is the most common human fungal pathogen, causes high mortality among immunocompromised patients. Antifungal drug resistance becomes a major challenge for the management of Candida infection. Diorcinol D (DD), a diphenyl ether derivative isolated from an endolichenic fungus, exerted fungicidal action against Candida species. In this study, we investigated the possible mechanism of its antifungal activity. The change of membrane dynamics and permeability suggested that the cell membrane was disrupted by the treatment of DD. This was further supported by the evidences of intracellular glycerol accumulation, alteration of cell ultrastructure, and down-regulation of genes involved in cell membrane synthesis. In addition, the treatment of C. albicans with DD resulted in the elevation of reactive oxygen species (ROS), which caused the dysfunction of mitochondria. These altogether suggested that DD exerted its antifungal activity through cytoplasmic membrane destruction and ROS accumulation. This finding is helpful to uncover the underlying mechanisms for the diphenyl ether derivatives and provides a potential application in fighting clinical fungal infections. PMID:26047493

  17. Specificity of drug transport mediated by CaMDR1: a major facilitator of Candida albicans

    Indian Academy of Sciences (India)

    Avmeet Kohli; Vinita Gupta; Shankarling Krishnamurthy; Seyed E Hasnain; Rajendra Prasad

    2001-09-01

    CaMDR1 encodes a major facilitator superfamily (MFS) protein in Candida albicans whose expression has been linked to azole resistance and which is frequently encountered in this human pathogenic yeast. In this report we have overexpressed CaMdr1p in Sf9 insect cells and demonstrated for the first time that it can mediate methotrexate (MTX) and fluconazole (FLC) transport. MTX appeared to be a better substrate for CaMdr1p among these two tested drugs. Due to severe toxicity of these drugs to insect cells, further characterization of CaMdr1p as a drug transporter could not be done with this system. Therefore, as an alternative, CaMdr1p and Cdr1p, which is an ABC protein (ATP binding cassette) also involved in azole resistance in C. albicans, were independently expressed in a common hypersensitive host JG436 of Saccharomyces cerevisiae. This allowed a better comparison between the functionality of the two export pumps. We observed that while both FLC and MTX are effluxed by CaMdr1p, MTX appeared to be a poor substrate for Cdr1p. JG436 cells expressing Cdr1p thus conferred resistance to other antifungal drugs but remained hypersensitive to MTX. Since MTX is preferentially transported by CaMdr1p, it can be used for studying the function of this MFS protein.

  18. Cap1p attenuates the apoptosis of Candida albicans.

    Science.gov (United States)

    Dai, Bao-Di; Wang, Yan; Zhao, Lan-Xue; Li, De-Dong; Li, Ming-Bang; Cao, Yong-Bing; Jiang, Yuan-Ying

    2013-06-01

    Candida albicans is the most common opportunistic fungal pathogen and its apoptosis is inducible by environmental stress. Based on our previous finding that transcription factor Cap1p was involved in baicalein-induced apoptosis, the present study aimed to further clarify the role of Cap1p in apoptosis by observing the impact of CAP1 deletion on cell fate. It was found that apoptotic stimulation with amphotericin B, acetic acid and hydrogen peroxide increased the number of apoptotic and necrotic cells, caspase activity and the accumulation of reactive oxygen species, whereas it decreased the mitochondrial membrane potential and intracellular ATP level in the cap1Δ/Δ mutant. The cell fate was, at least partly, caused by glutathione depletion and attenuation of the expression of the glutathione reductase gene in the cap1Δ/Δ mutant. Collectively, our data suggest that Cap1p participated in the apoptosis of C. albicans by regulating the expression of the glutathione reductase gene and glutathione content. PMID:23517286

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

    Science.gov (United States)

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

    2016-01-01

    The purpose of this study was to analyse specific molecular mechanisms involved in the intrinsic resistance of C. albicans biofilms to antifungals. We investigated the transcriptional profile of three genes (BGL2, SUN41, ECE1) involved in Candida cell wall formation in response to voriconazole or anidulafungin after the production of intermediate and mature biofilms. C. albicans M61, a well-documented biofilm producer strain, was used for the development of intermediate (12 h and 18 h) and completely mature biofilms (48 h). After exposure of cells from each biofilm growth mode to voriconazole (128 and 512 mg l(-1)) or anidulafungin (0.25 and 1 mg l(-1)) for 12-24 h, total RNA samples extracted from biofilm cells were analysed by RT-PCR. The voriconazole and anidulafungin biofilm MIC was 512 and 0.5 mg l(-1) respectively. Anidulafungin caused significant up-regulation of SUN41 (3.7-9.3-fold) and BGL2 (2.2-2.8 fold) in intermediately mature biofilms; whereas, voriconazole increased gene expression in completely mature biofilms (SUN41 2.3-fold, BGL2 2.1-fold). Gene expression was primarily down-regulated by voriconazole in intermediately, but not completely mature biofilms. Both antifungals caused down-regulation of ECE1 in intermediately mature biofilms. PMID:26593284

  20. The N-Linked Outer Chain Mannans and the Dfg5p and Dcw1p Endo-α-1,6-Mannanases Are Needed for Incorporation of Candida albicans Glycoproteins into the Cell Wall

    OpenAIRE

    Ao, Jie; Jennifer L Chinnici; Maddi, Abhiram; Free, Stephen J.

    2015-01-01

    A biochemical pathway for the incorporation of cell wall protein into the cell wall of Neurospora crassa was recently proposed. In this pathway, the DFG-5 and DCW-1 endo-α-1,6-mannanases function to covalently cross-link cell wall protein-associated N-linked galactomannans, which are structurally related to the yeast outer chain mannans, into the cell wall glucan-chitin matrix. In this report, we demonstrate that the mannosyltransferase enzyme Och1p, which is needed for the synthesis of the N...

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

    LENUS (Irish Health Repository)

    2009-03-01

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

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

    Science.gov (United States)

    Borecká-Melkusová, Silvia; Moran, Gary P; Sullivan, Derek J; Kucharíková, Sona; Chorvát, Dusan; Bujdáková, Helena

    2009-03-01

    The expression of the ERG1, ERG3, ERG7, ERG9, ERG11 and ERG25 genes in response to incubation with fluconazole and biofilm formation was investigated using reverse-transcription PCR and real-time PCR in Candida albicans and Candida dubliniensis clinical isolates. The viability of biofilm was measured using an 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay and confocal scanning laser microscopy (CSLM). Expression of the ERG11 gene was found to be low or moderate and it was regulated by fluconazole addition more so than by biofilm formation. Very low or non-detectable expression of ERG1, ERG7 and ERG25 genes was detected in C. albicans. The expression of the ERG9 increased in the presence of fluconazole in some isolates. Following incubation with fluconazole, formation of biofilm by C. dubliniensis was coupled with up-regulation of the ERG3 and ERG25 genes as have been observed previously in C. albicans. Planktonic cells of both Candida species released from biofilm displayed similar resistance mechanisms to fluconazole like attached cells. The XTT reduction assay and CSLM revealed that although incubation with fluconazole decreased the biofilm thickness, these were still comprised metabolically active cells able to disseminate and produce biofilm. Our data indicate that biofilm represents a highly adapted community reflecting the individuality of clinical isolates. PMID:18627475

  3. Operating Cell Temperature Determination in Flat-Plate Photovoltaic Modules

    International Nuclear Information System (INIS)

    Two procedures (simplified and complete) to determine me operating cell temperature in photovoltaic modules operating in real conditions assuming isothermal stationary modules are presented in this work. Some examples are included that show me dependence of this temperature on several environmental (sky, ground and ambient temperatures, solar irradiance, wind speed, etc.) and structural (module geometry and size, encapsulating materials, anti reflexive optical coatings, etc.) factors and also on electrical module performance. In a further step temperature profiles for non-isothermal modules are analysed besides transitory effects due to variable irradiance and wind gusts. (Author) 27 refs

  4. A radiolabel release microassay for phagocytic killing of Candida albicans

    International Nuclear Information System (INIS)

    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. (Auth.)

  5. Histone acetyltransferase Rtt109 is required for Candida albicans pathogenesis

    OpenAIRE

    Lopes da Rosa, Jessica; Boyartchuk, Victor L.; Zhu, Lihua Julie; Kaufman, Paul D.

    2010-01-01

    Candida albicans is a ubiquitous opportunistic pathogen that is the most prevalent cause of hospital-acquired fungal infections. In mammalian hosts, C. albicans is engulfed by phagocytes that attack the pathogen with DNA-damaging reactive oxygen species (ROS). Acetylation of histone H3 lysine 56 (H3K56) by the fungal-specific histone acetyltransferase Rtt109 is important for yeast model organisms to survive DNA damage and maintain genome integrity. To assess the importance of Rtt109 for C. al...

  6. Eisosomes promote the ability of Sur7 to regulate plasma membrane organization in Candida albicans

    Science.gov (United States)

    Wang, Hong X.; Douglas, Lois M.; Veselá, Petra; Rachel, Reinhard; Malinsky, Jan; Konopka, James B.

    2016-01-01

    The plasma membrane of the fungal pathogen Candida albicans forms a protective barrier that also mediates many processes needed for virulence, including cell wall synthesis, invasive hyphal morphogenesis, and nutrient uptake. Because compartmentalization of the plasma membrane is believed to coordinate these diverse activities, we examined plasma membrane microdomains termed eisosomes or membrane compartment of Can1 (MCC), which correspond to ∼200-nm-long furrows in the plasma membrane. A pil1∆ lsp1∆ mutant failed to form eisosomes and displayed strong defects in plasma membrane organization and morphogenesis, including extensive cell wall invaginations. Mutation of eisosome proteins Slm2, Pkh2, and Pkh3 did not cause similar cell wall defects, although pkh2∆ cells formed chains of furrows and pkh3∆ cells formed wider furrows, identifying novel roles for the Pkh protein kinases in regulating furrows. In contrast, the sur7∆ mutant formed cell wall invaginations similar to those for the pil1∆ lsp1∆ mutant even though it could form eisosomes and furrows. A PH-domain probe revealed that the regulatory lipid phosphatidylinositol 4,5-bisphosphate was enriched at sites of cell wall invaginations in both the sur7∆ and pil1∆ lsp1∆ cells, indicating that this contributes to the defects. The sur7∆ and pil1∆ lsp1∆ mutants displayed differential susceptibility to various types of stress, indicating that they affect overlapping but distinct functions. In support of this, many mutant phenotypes of the pil1∆ lsp1∆ cells were rescued by overexpressing SUR7. These results demonstrate that C. albicans eisosomes promote the ability of Sur7 to regulate plasma membrane organization. PMID:27009204

  7. Determinants of resting cerebral blood flow in sickle cell disease.

    Science.gov (United States)

    Bush, Adam M; Borzage, Matthew T; Choi, Soyoung; Václavů, Lena; Tamrazi, Benita; Nederveen, Aart J; Coates, Thomas D; Wood, John C

    2016-09-01

    Stroke is common in children with sickle cell disease and results from an imbalance in oxygen supply and demand. Cerebral blood flow (CBF) is increased in patients with sickle cell disease to compensate for their anemia, but adequacy of their oxygen delivery has not been systematically demonstrated. This study examined the physiological determinants of CBF in 37 patients with sickle cell disease, 38 ethnicity matched control subjects and 16 patients with anemia of non-sickle origin. Cerebral blood flow was measured using phase contrast MRI of the carotid and vertebral arteries. CBF increased inversely to oxygen content (r(2)  = 0.69, P Brain oxygen delivery, the product of CBF and oxygen content, was normal in all groups. Brain composition, specifically the relative amounts of grey and white matter, was the next strongest CBF predictor, presumably by influencing cerebral metabolic rate. Grey matter/white matter ratio and CBF declined monotonically until the age of 25 in all subjects, consistent with known maturational changes in brain composition. Further CBF reductions were observed with age in subjects older than 35 years of age, likely reflecting microvascular aging. On multivariate regression, CBF was independent of disease state, hemoglobin S, hemoglobin F, reticulocyte count and cell free hemoglobin, suggesting that it is regulated similarly in patients and control subjects. In conclusion, sickle cell disease patients had sufficient oxygen delivery at rest, but accomplish this only by marked increases in their resting CBF, potentially limiting their ability to further augment flow in response to stress. Am. J. Hematol. 91:912-917, 2016. © 2016 Wiley Periodicals, Inc. PMID:27263497

  8. Anti-Candida albicans activity, cytotoxicity and interaction with antifungal drugs of essential oils and extracts from aromatic and medicinal plants Actividad contra Candida albicans, citotoxicidad e interacción con antifúngicos de aceites esenciales y extractos de plantas medicinales y aromáticas

    Directory of Open Access Journals (Sweden)

    Verónica Tangarife-Castaño

    2011-09-01

    Full Text Available Objective: To determine anti-Candida albicans activity, cytotoxicity and drug interaction of essential oils and extracts from plants collected in Colombia. Materials and methods: The antifungal activity was evaluated following the AFST-EUCAST protocol. With most active samples, the inhibition of the formation of germ tubes and budding, the in vitro pharmacodynamics, using time-kill assays, and the interaction with itraconazole and amphotericin B following the chequerboard technique were evaluated. The cytotoxicity assay for all samples was done using MTT. Results: Strong activity in 17.57% of the samples was found. The lowest MIC values were obtained with Piper bredemeyeri Jacq and Lippia origanoides Kunth (B oils and Morinda royoc L extract. The three samples inhibited the formation of germ tubes and budding. P. bredemeyeri Jacq oil and M. royoc L extract samples showed fungicidal activity at 2xMIC. A synergistic effect was obtained with the combination of P. bredemeyeri Jacq oil and itraconazole, but not for the combination with amphotericin B. Active samples against C. albicans were not cytotoxic on Vero cells ATCC CCL-81, excluding P. bredemeyeri Jacq oil. Conclusions: The results of this study suggest that Colombian medicinal and aromatic plants represent an untapped source of compounds with anti-C. albicans activity that could be a resource in the development of new therapeutic natural products.Objetivo. Determinar la actividad anti-Candida albicans, la citotoxicidad y la interacción con antifúngicos de aceites y extractos de plantas recolectadas en Colombia. Materiales y métodos. La actividad antifúngica fue evaluada siguiendo el protocolo Antifungal Susceptibility Testing Subcommittee of the European Committee on Antimicrobial Susceptibility Testing (AFST-EUCAST. Con las muestras más activas se evaluó la inhibición de la formación de tubo germinal y la gemación, la farmacodinamia mediante curvas de tiempo muerte y la interacci

  9. Effects of 60 Cobalt ionizing radiation in morphology and metabolism of yeasts and Chlamydospore of Candida albicans

    International Nuclear Information System (INIS)

    Candida albicans is a fungus responsible for 80-90% of fungal infections, as the symptoms are similar to those of systemic bacterial infections there is a difficulty for immediate diagnosis. These difficulties can lead to delays of antifungal therapy, which contributes to the high mortality rates associated with this infection. Resistance structures referred to as chlamydospores are very common in the pathogen, representing different cell types that form in response to certain genetic or environmental conditions. Recently, various antifungal agents and new therapeutic strategies have come into use, allowing the fungus to acquire a resistance to the drugs. The use of ionizing radiation has been widely employed for the production of immunogens against various parasites. In this work, we evaluate the effects of gamma radiation (60Co) in yeast and chlamydospore of C. albicans with doses ranging from 320 to 10.240 Gy with Cobalt 60. Subsequently the samples were plated and after seven days, the colony forming units (CFU) told. The viability of irradiated cells were evaluated using the Janus green dye. A dose of 6000 Gy was considered ideal for the mitigation of chlamydospore and yeast. The dimorphic change mechanisms of both fungal structures were not harmed. The viability of chlamydospores remained above 70% while the yeast viability remained above 85%. By transmission electron microscopy and fluorescence microscopy may be noted cytoplasmic changes, defects in the cell wall, mitochondria, and the presence of partially preserved vesicles of both morphological forms of C. albicans. Irradiation both chlamydospore as C. albicans yeast allows the suppression of their reproduction, opening the possibility of their use in future candidate immunogens. (author)

  10. Effects of 60 Cobalt ionizing radiation in morphology and metabolism of yeasts and Chlamydospore of Candida albicans

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, Michel R.F.; Demicheli, Marina C.; Andrade Junior, Heitor F.; Galiesteo Junior, Andres A.J., E-mail: galisteo@usp.br [Universidade de Sao Paulo (IMTSP/USP), Sao Paulo, SP (Brazil). Instituto de Medicina Tropical. Lab. de Protozoologia; Takakura, Cleusa F.H. [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Departamento de Patologia de Molestias Transmissiveis. Lab. de Patologia; Negro, Gilda M.B. del [Universidade de Sao Paulo (HCFM/USP/IMTSP/LIM-53), Sao Paulo, SP (Brazil). Hospital das Clinicas. Lab. de Micologia; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Candida albicans is a fungus responsible for 80-90% of fungal infections, as the symptoms are similar to those of systemic bacterial infections there is a difficulty for immediate diagnosis. These difficulties can lead to delays of antifungal therapy, which contributes to the high mortality rates associated with this infection. Resistance structures referred to as chlamydospores are very common in the pathogen, representing different cell types that form in response to certain genetic or environmental conditions. Recently, various antifungal agents and new therapeutic strategies have come into use, allowing the fungus to acquire a resistance to the drugs. The use of ionizing radiation has been widely employed for the production of immunogens against various parasites. In this work, we evaluate the effects of gamma radiation ({sup 60}Co) in yeast and chlamydospore of C. albicans with doses ranging from 320 to 10.240 Gy with Cobalt 60. Subsequently the samples were plated and after seven days, the colony forming units (CFU) told. The viability of irradiated cells were evaluated using the Janus green dye. A dose of 6000 Gy was considered ideal for the mitigation of chlamydospore and yeast. The dimorphic change mechanisms of both fungal structures were not harmed. The viability of chlamydospores remained above 70% while the yeast viability remained above 85%. By transmission electron microscopy and fluorescence microscopy may be noted cytoplasmic changes, defects in the cell wall, mitochondria, and the presence of partially preserved vesicles of both morphological forms of C. albicans. Irradiation both chlamydospore as C. albicans yeast allows the suppression of their reproduction, opening the possibility of their use in future candidate immunogens. (author)

  11. Pathogenesis of Candida albicans Infections in the Alternative Chorio-Allantoic Membrane Chicken Embryo Model Resembles Systemic Murine Infections

    OpenAIRE

    Jacobsen, Ilse D; Große, Katharina; Berndt, Angela; Hube, Bernhard

    2011-01-01

    Alternative models of microbial infections are increasingly used to screen virulence determinants of pathogens. In this study, we investigated the pathogenesis of Candida albicans and C. glabrata infections in chicken embryos infected via the chorio-allantoic membrane (CAM) and analyzed the virulence of deletion mutants. The developing immune system of the host significantly influenced susceptibility: With increasing age, embryos became more resistant and mounted a more balanced immune respon...

  12. Evaluation of the genotoxic and mutagenic potentials of homeopathic Candida albicans solutions

    Directory of Open Access Journals (Sweden)

    André Luis Santos

    2011-09-01

    Full Text Available Background: Candida spp is naturally found in humans’ flora of skin, gastrointestinal and genitourinary tracts and, in general, up to 75% of the population does not have any symptom [1]. However, oral candidiasis is very common among HIV patients and patients undergoing chemotherapy. The treatment of oral candidiasis is necessary once the disease causes discomfort and dysphagia, resulting in poor nutrition, slow recovery, and prolonged hospital stay [2,3]. Preliminary results obtained by our group with a new biotherapic prepared from Candida albicans (Candida 30x showed a great potential to reduce the candida yeast adhesion rate when the epithelial cells were pre-treated. This study is currently being developed with the evaluation of mutagenic and genotoxic potentials of several homeopathic solutions. Aims: The goal of this study was to assess the genotoxic and mutagenic potentials of different homeopathic potencies of C. albicans. Methodology: One part of C. albicans yeast obtained from Brazilian patient’s blood [4] was diluted in 9 parts of sterile water. This sample was submitted to 100 mechanical succussions (approximately 3 Hz, using Autic® Brazilian machine, originating the first dilution (1x. Then, 1 ml of this solution was diluted in 9 ml of solvent, submitted to 100 succussions, obtaining 2x potency. This procedure was successively repeated to obtain 30x potency, according to Brazilian Homeopathic Pharmacopoeia [5]. By the same technique, water vehicle was prepared until 30x to be used as control. All samples were prepared in sterile and aseptic conditions, using laminar flow cabinet, class II and were stored in the refrigerator (8ºC. The samples 1x, 6x, 12x, 18x, 24x and 30x of C. albicans and water 30x (vehicle control were analysed by: the Inductest, which assesses the ability of physical or chemical agents to promote lysogenic induction as a reflection of damage in DNA

  13. Mechanism of enhancement of microbial cell hydrophobicity by cationic polymers.

    OpenAIRE

    Goldberg, S; Doyle, R J; Rosenberg, M

    1990-01-01

    Polycationic polymers have been noted for their effects in promoting cell adhesion to various surfaces, but previous studies have failed to describe a mechanism dealing with this type of adhesion. In the present study, three polycationic polymers (chitosan, poly-L-lysine, and lysozyme) were tested for their effects on microbial hydrophobicity, as determined by adhesion to hydrocarbon and polystyrene. Test strains (Escherichia coli, Candida albicans, and a nonhydrophobic mutant, MR-481, derive...

  14. Role of Notch signaling in cell-fate determination of human mammary stem/progenitor cells

    International Nuclear Information System (INIS)

    Notch signaling has been implicated in the regulation of cell-fate decisions such as self-renewal of adult stem cells and differentiation of progenitor cells along a particular lineage. Moreover, depending on the cellular and developmental context, the Notch pathway acts as a regulator of cell survival and cell proliferation. Abnormal expression of Notch receptors has been found in different types of epithelial metaplastic lesions and neoplastic lesions, suggesting that Notch may act as a proto-oncogene. The vertebrate Notch1 and Notch4 homologs are involved in normal development of the mammary gland, and mutated forms of these genes are associated with development of mouse mammary tumors. In order to determine the role of Notch signaling in mammary cell-fate determination, we have utilized a newly described in vitro system in which mammary stem/progenitor cells can be cultured in suspension as nonadherent 'mammospheres'. Notch signaling was activated using exogenous ligands, or was inhibited using previously characterized Notch signaling antagonists. Utilizing this system, we demonstrate that Notch signaling can act on mammary stem cells to promote self-renewal and on early progenitor cells to promote their proliferation, as demonstrated by a 10-fold increase in secondary mammosphere formation upon addition of a Notch-activating DSL peptide. In addition to acting on stem cells, Notch signaling is also able to act on multipotent progenitor cells, facilitating myoepithelial lineage-specific commitment and proliferation. Stimulation of this pathway also promotes branching morphogenesis in three-dimensional Matrigel cultures. These effects are completely inhibited by a Notch4 blocking antibody or a gamma secretase inhibitor that blocks Notch processing. In contrast to the effects of Notch signaling on mammary stem/progenitor cells, modulation of this pathway has no discernable effect on fully committed, differentiated, mammary epithelial cells. These studies

  15. Determination of the pore size of cell walls of living plant cells

    Energy Technology Data Exchange (ETDEWEB)

    Carpita, N.; Sabularse, D.; Montezinos, D.; Delmer, D.P.

    1979-09-14

    The limiting diameter of pores in the walls of living plant cells through which molecules can freely pass has been determined by a solute exclusion technique to be 35 to 38 angstroms for hair cells of Raphanus sativus roots and fibers of Gossypium hirsutum, 38 to 40 angstroms for cultured cells of Acer pseudoplatanus, and 45 to 52 angstroms for isolated palisade parenchyma cells of the leaves of Xanthium strumarium and Commelina communis. These results indicate that molecules with diameters larger than these pores would be restricted in their ability to penetrate such a cell wall, and that such a wall may represent a more significant barrier to cellular communication than has been previously assumed.

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

    Directory of Open Access Journals (Sweden)

    Anja Wartenberg

    2014-12-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

    Benso, Bruna; Pardi, Vanessa

    2016-01-01

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

  19. Purification and germination of Candida albicans and Candida dubliniensis chlamydospores cultured in liquid media.

    LENUS (Irish Health Repository)

    Citiulo, Francesco

    2009-10-01

    Candida albicans and Candida dubliniensis are the only Candida sp. that have been observed to produce chlamydospores. The function of these large, thick-walled cells is currently unknown. In this report, we describe the production and purification of chlamydospores from these species in defined liquid media. Staining with the fluorescent dye FUN-1 indicated that chlamydospores are metabolically active cells, but that metabolic activity is undetectable in chlamydospores that are >30 days old. However, 5-15-day-old chlamydospores could be induced to produce daughter chlamydospores, blastospores, pseudohyphae and true hyphae depending on the incubation conditions used. Chlamydospores that were preinduced to germinate were also observed to escape from murine macrophages following phagocytosis, suggesting that these structures may be viable in vivo. Mycelium-attached and purified chlamydospores rapidly lost their viability in water and when subjected to dry stress, suggesting that they are unlikely to act as long-term storage structures. Instead, our data suggest that chlamydospores represent an alternative specialized form of growth by C. albicans and C. dubliniensis.

  20. Cellular Structural Changes in Candida albicans Caused by the Hydroalcoholic Extract from Sapindus saponaria L.

    Science.gov (United States)

    Shinobu-Mesquita, Cristiane S; Bonfim-Mendonça, Patricia S; Moreira, Amanda L; Ferreira, Izabel C P; Donatti, Lucelia; Fiorini, Adriana; Svidzinski, Terezinha I E

    2015-01-01

    Vulvovaginal candidiasis (VVC) is a disease caused by the abnormal growth of yeast-like fungi in the mucosa of the female genital tract. Candida albicans is the principal etiological agent involved in VVC, but reports have shown an increase in the prevalence of Candida non-C. albicans (CNCA) cases, which complicates VVC treatment because CNCA does not respond well to antifungal therapy. Our group has reported the in vitro antifungal activity of extracts from Sapindus saponaria L. The present study used scanning electron microscopy and transmission electron microscopy to further evaluate the antifungal activity of hydroalcoholic extract from S. saponaria (HE) against yeast obtained from VVC and structural changes induced by HE. We observed the antifungal activity of HE against 125 vaginal yeasts that belonged to four different species of the Candida genus and S. cerevisae. The results suggest that saponins that are present in HE act on the cell wall or membrane of yeast at the first moments after contact, causing damage to these structures and cell lysis. PMID:26007191