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Sample records for albicans determines cell

  1. The determination of optimal cells disintegration method of Candida albicans and Candida tropicalis fungals

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    M. V. Rybalkyn

    2014-08-01

    Candida tropicalis fungi has been prepared separately on Sabouraud agar. Incubation has been done at 25 ± 2º C for 6 days and then washed by 25 ml of sterile 0.9% isotonic sodium chloride solution. We determined the microbiological purity of cell suspension of Candida albicans and Candida tropicalis fungi visually and by microscopy. Further washings has been obtained by centrifuged at speed 3000 r / min for 10 min. The resulting precipitate of fungi has been proved by sterile isotonic 0.9% sodium chloride solution to (8,5 – 9х108 in 1 ml of standardized suspension and by counting the cells in the Goryaeva fungi cell. For cell disruption fungi has been resorted to the action of ultrasound, rubbing with abrasive material and freeze-thaw. Key parameters in the ultrasonic disintegration are: frequency 22 kHz, the intensity of 5 W/cm2, a temperature of 25 ± 2° C, time 15 minutes, 10 ml of 0,9% isotonic sterile sodium chloride solution. For grinding fungal cells using mortar, pestle, quartz sand and biomaterial in a 1:1 ratio, and 10 mL of sterile isotonic 0,9% sodium chloride solution. Freezing and thawing have been performed in 10 ml sterile isotonic 0.9% sodium chloride solution at a temperature of -25 ± 2 ° C and 25 ± 2 ° C. In each case the amount of protein and polysaccharides has been calculated. For a more detailed analysis the monosaccharide composition has been determined in each case. It is possible to establish the optimal method of cell disruption of Candida albicans and Candida tropicalis fungi, namely ultrasonic disintegration. In the future we plan to study the immunological properties of the proteins and polysaccharides on animals.

  2. A multifunctional mannosyltransferase family in Candida albicans determines cell wall mannan structure and host-fungus interactions.

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    Mora-Montes, Héctor M; Bates, Steven; Netea, Mihai G; Castillo, Luis; Brand, Alexandra; Buurman, Ed T; Díaz-Jiménez, Diana F; Jan Kullberg, Bart; Brown, Alistair J P; Odds, Frank C; Gow, Neil A R

    2010-04-16

    The cell wall proteins of fungi are modified by N- and O-linked mannosylation and phosphomannosylation, resulting in changes to the physical and immunological properties of the cell. Glycosylation of cell wall proteins involves the activities of families of endoplasmic reticulum and Golgi-located glycosyl transferases whose activities are difficult to infer through bioinformatics. The Candida albicans MNT1/KRE2 mannosyl transferase family is represented by five members. We showed previously that Mnt1 and Mnt2 are involved in O-linked mannosylation and are required for virulence. Here, the role of C. albicans MNT3, MNT4, and MNT5 was determined by generating single and multiple MnTDelta null mutants and by functional complementation experiments in Saccharomyces cerevisiae. CaMnt3, CaMnt4, and CaMnt5 did not participate in O-linked mannosylation, but CaMnt3 and CaMnt5 had redundant activities in phosphomannosylation and were responsible for attachment of approximately half of the phosphomannan attached to N-linked mannans. CaMnt4 and CaMnt5 participated in N-mannan branching. Deletion of CaMNT3, CaMNT4, and CaMNT5 affected the growth rate and virulence of C. albicans, affected the recognition of the yeast by human monocytes and cytokine stimulation, and led to increased cell wall chitin content and exposure of beta-glucan at the cell wall surface. Therefore, the MNT1/KRE2 gene family participates in three types of protein mannosylation in C. albicans, and these modifications play vital roles in fungal cell wall structure and cell surface recognition by the innate immune system.

  3. Cell wall glycans and soluble factors determine the interactions between the hyphae of Candida albicans and Pseudomonas aeruginosa.

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    Brand, Alexandra; Barnes, Julia D; Mackenzie, Kevin S; Odds, Frank C; Gow, Neil A R

    2008-10-01

    The fungus, Candida albicans, and the bacterium, Pseudomonas aeruginosa, are opportunistic human pathogens that have been coisolated from diverse body sites. Pseudomonas aeruginosa suppresses C. albicans proliferation in vitro and potentially in vivo but it is the C. albicans hyphae that are killed while yeast cells are not. We show that hyphal killing involves both contact-mediated and soluble factors. Bacterial culture filtrates contained heat-labile soluble factors that killed C. albicans hyphae. In cocultures, localized points of hyphal lysis were observed, suggesting that adhesion and subsequent bacteria-mediated cell wall lysis is involved in the killing of C. albicans hyphae. The glycosylation status of the C. albicans cell wall affected the rate of contact-dependent killing because mutants with severely truncated O-linked, but not N-linked, glycans were hypersensitive to Pseudomonas-mediated killing. Deletion of HWP1, ALS3 or HYR1, which encode major hypha-associated cell wall proteins, had no effect on fungal susceptibility.

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

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

    1986-01-01

    [ 3 H]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, [ 3 H]glucose was added for 3 h and the amount of radiolabel incorporated into residual candida was measured. The results showed that [ 3 H]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. Candida albicans Hom6 is a homoserine dehydrogenase involved in protein synthesis and cell adhesion

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    Pei-Wen Tsai

    2017-12-01

    Full Text Available Background/Purpose: Candida albicans is a common fungal pathogen in humans. In healthy individuals, C. albicans represents a harmless commensal organism, but infections can be life threatening in immunocompromised patients. The complete genome sequence of C. albicans is extremely useful for identifying genes that may be potential drug targets and important for pathogenic virulence. However, there are still many uncharacterized genes in the Candida genome database. In this study, we investigated C. albicans Hom6, the functions of which remain undetermined experimentally. Methods: HOM6-deleted and HOM6-reintegrated mutant strains were constructed. The mutant strains were compared with wild-type in their growth in various media and enzyme activity. Effects of HOM6 deletion on translation were further investigated by cell susceptibility to hygromycin B or cycloheximide, as well as by polysome profiling, and cell adhesion to polystyrene was also determined. Results: C. albicans Hom6 exhibits homoserine dehydrogenase activity and is involved in the biosynthesis of methionine and threonine. HOM6 deletion caused translational arrest in cells grown under amino acid starvation conditions. Additionally, Hom6 protein was found in both cytosolic and cell-wall fractions of cultured cells. Furthermore, HOM6 deletion reduced C. albicans cell adhesion to polystyrene, which is a common plastic used in many medical devices. Conclusion: Given that there is no Hom6 homologue in mammalian cells, our results provided an important foundation for future development of new antifungal drugs. Keywords: Candida albicans, cell adhesion, Hom6, homoserine dehydrogenase, protein synthesis

  6. Induction of suppressor cells in vitro by Candida albicans.

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    Cuff, C F; Rogers, C M; Lamb, B J; Rogers, T J

    1986-06-01

    Normal splenocytes cultured with Formalin-killed Candida albicans were shown to acquire significant suppressor cell activity in a period of 3 days. These cells were found to suppress both the phytohemagglutinin-induced mitogen response as well as the anti-sheep erythrocyte antibody response. Experiments were carried out to determine the nature of the suppressor cell population. Results showed that these cells were not susceptible to treatment with anti-Thy 1 antibody and complement. Panning experiments showed that the suppressor cells were not plastic-adherent or Mac-1 antigen-positive. The suppressor cells were, however, adherent to anti-mouse immunoglobulin (F(ab')2-fragment)-coated dishes. Additional experiments showed that the suppressor cell activity was susceptible to treatment with monoclonal anti-Lyb 2.1 antibody and complement. These results suggest that the suppressor cell induced in vitro by Candida is a member of the B-lymphocyte lineage.

  7. A multifunctional mannosyltransferase family in Candida albicans determines cell wall mannan structure and host-fungus interactions.

    NARCIS (Netherlands)

    Mora-Montes, H.M.; Bates, S.; Netea, M.G.; Castillo, L.; Brand, A.; Buurman, E.T.; Diaz-Jimenez, D.F.; Kullberg, B.J.; Brown, A.J.; Odds, F.C.; Gow, N.A.

    2010-01-01

    The cell wall proteins of fungi are modified by N- and O-linked mannosylation and phosphomannosylation, resulting in changes to the physical and immunological properties of the cell. Glycosylation of cell wall proteins involves the activities of families of endoplasmic reticulum and Golgi-located

  8. Selection of aptamers for Candida albicans by cell-SELEX

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    Miranda, Alessandra Nunes Duarte

    2017-01-01

    The growing concern with invasive fungal infections, responsible for an alarming mortality rate of immunosuppressed patients and in Intensive Care Units, evidences the need for a fast and specific method for the Candida albicans detection, since this species is identified as one of the main causes of septicemia. Commonly, it is a challenge for clinicians to determine the primary infection foci, the dissemination degree, or whether the site of a particular surgery is involved. Although scintigraphic imaging represents a promising tool for infectious foci detection, it still lacks a methodology for C. albicans diagnosis due to the absence of specific radiotracers for this microorganism. Aptamers are molecules that have almost ideal properties for use as diagnostic radiopharmaceuticals, such as high specificity for their molecular targets, lack of immunogenicity and toxicity, high tissue penetration and rapid blood clearance. Aptamers can also be labeled with different radionuclides. This work aims to obtain aptamers for specific binding to C. albicans cells for future application as a radiopharmaceutical. It was used a variation of the SELEX (Systematic Evolution of Ligands by EXponential Enrichment) technique, termed cell-SELEX, in which cells are the targets for selection. A selection protocol was standardized using a random library of single-stranded oligonucleotides, each containing two fixed regions flanking a sequence of 40 random nucleotides. This library was incubated with C. albicans cells in the presence of competitors. Then, the binding sequences were separated by centrifugation, resuspended and amplified by PCR. The amplification was confirmed by agarose gel electrophoresis. After that, the ligands were purified to obtain a new pool of ssDNA, from which a new incubation was carried out. The selection parameters were gradually modified in order to increase stringency. This cycle was repeated 12 times to allow the selection of sequences with the maximum

  9. Selection of aptamers for Candida albicans by cell-SELEX; Selecao de aptameros para Candida albicans por cell-SELEX

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    Miranda, Alessandra Nunes Duarte

    2017-07-01

    The growing concern with invasive fungal infections, responsible for an alarming mortality rate of immunosuppressed patients and in Intensive Care Units, evidences the need for a fast and specific method for the Candida albicans detection, since this species is identified as one of the main causes of septicemia. Commonly, it is a challenge for clinicians to determine the primary infection foci, the dissemination degree, or whether the site of a particular surgery is involved. Although scintigraphic imaging represents a promising tool for infectious foci detection, it still lacks a methodology for C. albicans diagnosis due to the absence of specific radiotracers for this microorganism. Aptamers are molecules that have almost ideal properties for use as diagnostic radiopharmaceuticals, such as high specificity for their molecular targets, lack of immunogenicity and toxicity, high tissue penetration and rapid blood clearance. Aptamers can also be labeled with different radionuclides. This work aims to obtain aptamers for specific binding to C. albicans cells for future application as a radiopharmaceutical. It was used a variation of the SELEX (Systematic Evolution of Ligands by EXponential Enrichment) technique, termed cell-SELEX, in which cells are the targets for selection. A selection protocol was standardized using a random library of single-stranded oligonucleotides, each containing two fixed regions flanking a sequence of 40 random nucleotides. This library was incubated with C. albicans cells in the presence of competitors. Then, the binding sequences were separated by centrifugation, resuspended and amplified by PCR. The amplification was confirmed by agarose gel electrophoresis. After that, the ligands were purified to obtain a new pool of ssDNA, from which a new incubation was carried out. The selection parameters were gradually modified in order to increase stringency. This cycle was repeated 12 times to allow the selection of sequences with the maximum

  10. Novel insight into neutrophil immune responses by dry mass determination of Candida albicans morphotypes.

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    Ava Hosseinzadeh

    Full Text Available The common fungal pathogen Candida albicans has the ability to grow as a yeast or as a hypha and can alternate between these morphotypes. The overall biomass of both morphotypes increases with growth. However, only yeasts, but not hyphae, exist as discrete cellular entities. Multiplicity of infection (MOI is a useful parameter to determine the initial inoculum of yeasts for in vitro infection assays. Since the amount of hyphae is difficult to quantify, comparable starting conditions in such assays cannot be determined accurately for yeasts and hyphae using MOI. To circumvent this problem, we have established a set of correlation coefficients to convert fungal metabolic activity and optical density to dry mass. Using these correlations, we were able to accurately compare ROS production and IL-8 release by polymorphonuclear neutrophils upon infection with equal dry mass amounts of yeast and hyphal morphotypes. Neutrophil responses depended on the initial form of infection, irrespective of C. albicans wild-type yeasts transforming to hyphal growth during the assay. Infection with a high mass of live C. albicans yeasts resulted in lower neutrophil ROS and this decrease stems from efficient ROS detoxification by C. albicans without directly affecting the phagocyte ROS machinery. Moreover, we show that dead C. albicans induces significantly less ROS and IL-8 release than live fungi, but thimerosal-killed C. albicans were still able to detoxify neutrophil ROS. Thus, the dry mass approach presented in this study reveals neutrophil responses to different amounts and morphotypes of C. albicans and serves as a template for studies that aim to identify morphotype-specific responses in a variety of immune cells.

  11. Psd1 Effects on Candida albicans Planktonic Cells and Biofilms

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    Sónia Gonçalves

    2017-06-01

    Full Text Available Candida albicans is an important human pathogen, causing opportunistic infections. The adhesion of planktonic cells to a substrate is the first step for biofilm development. The antimicrobial peptide (AMP Psd1 is a defensin isolated from Pisum sativum seeds. We tested the effects of this AMP on C. albicans biofilms and planktonic cells, comparing its activity with amphotericin B and fluconazole. Three C. albicans variants were studied, one of them a mutant deficient in glucosylceramide synthase, conferring resistance to Psd1 antifungal action. Atomic force microscopy (AFM was used to assess morphological and biomechanical changes on fungal cells. Surface alterations, with membrane disruption and leakage of cellular contents, were observed. Cytometry assays and confocal microscopy imaging showed that Psd1 causes cell death, in a time and concentration-dependent manner. These results demonstrate Psd1 pleiotropic action against a relevant fungal human pathogen, suggesting its use as natural antimycotic agent.

  12. Spaceflight enhances cell aggregation and random budding in Candida albicans.

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    Aurélie Crabbé

    Full Text Available This study presents the first global transcriptional profiling and phenotypic characterization of the major human opportunistic fungal pathogen, Candida albicans, grown in spaceflight conditions. Microarray analysis revealed that C. albicans subjected to short-term spaceflight culture differentially regulated 452 genes compared to synchronous ground controls, which represented 8.3% of the analyzed ORFs. Spaceflight-cultured C. albicans-induced genes involved in cell aggregation (similar to flocculation, which was validated by microscopic and flow cytometry analysis. We also observed enhanced random budding of spaceflight-cultured cells as opposed to bipolar budding patterns for ground samples, in accordance with the gene expression data. Furthermore, genes involved in antifungal agent and stress resistance were differentially regulated in spaceflight, including induction of ABC transporters and members of the major facilitator family, downregulation of ergosterol-encoding genes, and upregulation of genes involved in oxidative stress resistance. Finally, downregulation of genes involved in actin cytoskeleton was observed. Interestingly, the transcriptional regulator Cap1 and over 30% of the Cap1 regulon was differentially expressed in spaceflight-cultured C. albicans. A potential role for Cap1 in the spaceflight response of C. albicans is suggested, as this regulator is involved in random budding, cell aggregation, and oxidative stress resistance; all related to observed spaceflight-associated changes of C. albicans. While culture of C. albicans in microgravity potentiates a global change in gene expression that could induce a virulence-related phenotype, no increased virulence in a murine intraperitoneal (i.p. infection model was observed under the conditions of this study. Collectively, our data represent an important basis for the assessment of the risk that commensal flora could play during human spaceflight missions. Furthermore, since the

  13. The PHR Family: The Role of Extracellular Transglycosylases in Shaping Candida albicans Cells

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    Laura Popolo

    2017-10-01

    Full Text Available Candida albicans is an opportunistic microorganism that can become a pathogen causing mild superficial mycosis or more severe invasive infections that can be life-threatening for debilitated patients. In the etiology of invasive infections, key factors are the adaptability of C. albicans to the different niches of the human body and the transition from a yeast form to hypha. Hyphal morphology confers high adhesiveness to the host cells, as well as the ability to penetrate into organs. The cell wall plays a crucial role in the morphological changes C. albicans undergoes in response to specific environmental cues. Among the different categories of enzymes involved in the formation of the fungal cell wall, the GH72 family of transglycosylases plays an important assembly role. These enzymes cut and religate β-(1,3-glucan, the major determinant of cell shape. In C. albicans, the PHR family encodes GH72 enzymes, some of which work in specific environmental conditions. In this review, we will summarize the work from the initial discovery of PHR genes to the study of the pH-dependent expression of PHR1 and PHR2, from the characterization of the gene products to the recent findings concerning the stress response generated by the lack of GH72 activity in C. albicans hyphae.

  14. Culture Supernatants of Lactobacillus gasseri and L. crispatus Inhibit Candida albicans Biofilm Formation and Adhesion to HeLa Cells.

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    Matsuda, Yuko; Cho, Otomi; Sugita, Takashi; Ogishima, Daiki; Takeda, Satoru

    2018-03-30

    Vulvovaginal candidiasis (VVC) is a common superficial infection of the vaginal mucous membranes caused by the fungus Candida albicans. The aim of this study was to assess the mechanisms underlying the inhibitory effects of the culture supernatants of Lactobacillus gasseri and L. crispatus, the predominant microbiota in Asian healthy women, on C. albicans biofilm formation. The inhibition of C. albicans adhesion to HeLa cells by Lactobacillus culture supernatant was also investigated. Candida albicans biofilm was formed on polystyrene flat-bottomed 96-well plates, and the inhibitory effects on the initial colonization and maturation phases were determined using the XTT reduction assay. The expression levels of biofilm formation-associated genes (HWP1, ECE1, ALS3, BCR1, EFG1, TEC1, and CPH1) were determined by reverse transcription quantitative polymerase chain reaction. The inhibition of C. albicans adhesion to HeLa cells by Lactobacillus culture supernatant was evaluated by enumerating viable C. albicans cells. The culture supernatants of both Lactobacillus species inhibited the initial colonization and maturation of C. albicans biofilm. The expression levels of all biofilm formation-related genes were downregulated in the presence of Lactobacillus culture supernatant. The culture supernatant also inhibited C. albicans adhesion to HeLa cells. The culture supernatants of L. gasseri and L. crispatus inhibited C. albicans biofilm formation by downregulating biofilm formation-related genes and C. albicans adhesion to HeLa cells. These findings support the notion that Lactobacillus metabolites may be useful alternatives to antifungal drugs for the management of VVC.

  15. 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

  16. Human vaginal epithelial cells augment autophagy marker genes in response to Candida albicans infection.

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    Shroff, Ankit; Sequeira, Roicy; Reddy, Kudumula Venkata Rami

    2017-04-01

    Autophagy plays an important role in clearance of intracellular pathogens. However, no information is available on its involvement in vaginal infections such as vulvo-vaginal candidiasis (VVC). VVC is intimately associated with the immune status of the human vaginal epithelial cells (VECs). The objective of our study is to decipher if autophagy process is involved during Candida albicans infection of VECs. In this study, C. albicans infection system was established using human VEC line (VK2/E6E7). Infection-induced change in the expression of autophagy markers like LC3 and LAMP-1 were analyzed by RT-PCR, q-PCR, Western blot, immunofluorescence and transmission electron microscopy (TEM) studies were carried out to ascertain the localization of autophagosomes. Multiplex ELISA was carried out to determine the cytokine profiles. Analysis of LC3 and LAMP-1 expression at mRNA and protein levels at different time points revealed up-regulation of these markers 6 hours post C. albicans infection. LC3 and LAMP-1 puncti were observed in infected VECs after 12 hours. TEM studies showed C. albicans entrapped in autophagosomes. Cytokines-TNF-α and IL-1β were up-regulated in culture supernatants of VECs at 12 hours post-infection. The results suggest that C. albicans invasion led to the activation of autophagy as a host defense mechanism of VECs. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Distribution of Candida albicans and non-albicans Candida species in oral candidiasis patients: Correlation between cell surface hydrophobicity and biofilm forming activities.

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    Muadcheingka, Thaniya; Tantivitayakul, Pornpen

    2015-06-01

    The purposes of this investigation were to study the prevalence of Candida albicans and non-albicans Candida (NAC) species from oral candidiasis patients and evaluate the cell surface hydrophobicity (CSH) and biofilm forming capacity of the clinical isolates Candida species from oral cavity. This study identified a total of 250 Candida strains isolated from 207 oral candidiasis patients with PCR-RFLP technique. CSH value, total biomass of biofilm and biofilm forming ability of 117 oral Candida isolates were evaluated. C. albicans (61.6%) was still the predominant species in oral candidiasis patients with and without denture wearer, respectively, followed by C. glabrata (15.2%), C. tropicalis (10.4%), C. parapsilosis (3.2%), C. kefyr (3.6%), C. dubliniensis (2%), C. lusitaniae (2%), C. krusei (1.6%), and C. guilliermondii (0.4%). The proportion of mixed colonization with more than one Candida species was 18% from total cases. The relative CSH value and biofilm biomass of NAC species were greater than C. albicans (poral isolates NAC species had biofilm forming ability, whereas 78% of C. albicans were biofilm formers. Furthermore, the significant difference of relative CSH values between biofilm formers and non-biofilm formers was observed in the NAC species (poral cavity was gradually increasing. The possible contributing factors might be high cell surface hydrophobicity and biofilm forming ability. The relative CSH value could be a putative factor for determining biofilm formation ability of the non-albicans Candida species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Effect of Schinus terebinthifolius on Candida albicans growth kinetics, cell wall formation and micromorphology.

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    Alves, Lívia Araújo; Freires, Irlan de Almeida; Pereira, Tricia Murielly; de Souza, Andrade; Lima, Edeltrudes de Oliveira; de Castro, Ricardo Dias

    2013-01-01

    To evaluate the anti-fungal activity of a tincture from Schinus terebinthifolius (Brazilian pepper tree) on Candida albicans (ATCC 289065), a micro-organism associated with fungal infections of the oral cavity. Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) were determined through microdilution technique, as well as the microbial growth curve of C. albicans promoted by S. terebinthifolius. In addition, this study investigated a possible activity of the product on the fungal cell wall and its biological activity on fungal morphology. Nystatin was used as control and all tests were performed in triplicate. S. terebinthifolius showed MIC of 312.5 µg/mL and MFC of 2500 µg/mL upon the strain tested, while Nystatin showed MIC and MFC of 6.25 µg/mL. As regards the microbial growth curve, S. terebinthifolius was able to significantly reduce the number of CFU/mL when compared to growth control until the time of 60 min. In the times 120 and 180 min there was no statistically significant difference between the growth control and the experimental product. S. terebinthifolius possibly acts on the fungal cell wall, once the sorbitol test indicated a MIC of 1250 µg/mL. In the fungal morphology, a reduction was observed of pseudo-hyphae, chlamydoconidia and blastoconidia in the presence of the experimental product. S. terebinthifolius showed anti-fungal activity against C. albicans, inhibiting, probably, the fungal cell wall formation.

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

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

    2016-11-01

    Candida spp. can adhere to and form biofilms over different surfaces, becoming less susceptible to antifungal treatment. Resistance of biofilms to antifungal agents is multifactorial and the extracellular matrix (ECM) appears to play an important role. Among the few available antifungals for treatment of candidaemia, only the lipid formulations of amphotericin B (AmB) and the echinocandins are effective against biofilms. Our group has previously demonstrated that miltefosine has an important effect against Candida albicans biofilms. Thus, the aim of this work was to expand the analyses of the in vitro antibiofilm activity of miltefosine to non-albicans Candida spp. Miltefosine had significant antifungal activity against planktonic cells and the development of biofilms of C. albicans, Candida parapsilosis, Candida tropicalis and Candida glabrata. The activity profile in biofilms was superior to fluconazole and was similar to that of AmB and caspofungin. Biofilm-derived cells with their ECM extracted became as susceptible to miltefosine as planktonic cells, confirming the importance of the ECM in the biofilm resistant behaviour. Miltefosine also inhibited biofilm dispersion of cells at the same concentration needed to inhibit planktonic cell growth. The data obtained in this work reinforce the potent inhibitory activity of miltefosine on biofilms of the four most pathogenic Candida spp. and encourage further studies for the utilisation of this drug and/or structural analogues on biofilm-related infections. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

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

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    Humidah Alanazi

    2014-01-01

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

  1. Identification of virulence determinants of the human pathogenic fungi Aspergillus fumigatus and Candida albicans by proteomics.

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    Kniemeyer, Olaf; Schmidt, André D; Vödisch, Martin; Wartenberg, Dirk; Brakhage, Axel A

    2011-06-01

    Both fungi Candida albicans and Aspergillus fumigatus can cause a number of life-threatening systemic infections in humans. The commensal yeast C. albicans is one of the main causes of nosocomial fungal infectious diseases, whereas the filamentous fungus A. fumigatus has become one of the most prevalent airborne fungal pathogens. Early diagnosis of these fungal infections is challenging, only a limited number of antifungals for treatment are available, and the molecular details of pathogenicity are hardly understood. The completion of both the A. fumigatus and C. albicans genome sequence provides the opportunity to improve diagnosis, to define new drug targets, to understand the functions of many uncharacterised proteins, and to study protein regulation on a global scale. With the application of proteomic tools, particularly two-dimensional gel electrophoresis and LC/MS-based methods, a comprehensive overview about the proteins of A. fumigatus and C. albicans present or induced during environmental changes and stress conditions has been obtained in the past 5 years. However, for the discovery of further putative virulence determinants, more sensitive and targeted proteomic methods have to be applied. Here, we review the recent proteome data generated for A. fumigatus and C. albicans that are related to factors required for pathogenicity. Copyright © 2011 Elsevier GmbH. All rights reserved.

  2. Cell damage caused by vaginal Candida albicans isolates from women with different symptomatologies.

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    Faria, Daniella Renata; Sakita, Karina Mayumi; Akimoto-Gunther, Luciene Setsuko; Kioshima, Érika Seki; Svidzinski, Terezinha Inez Estivalet; Bonfim-Mendonça, Patrícia de Souza

    2017-08-01

    The present study aimed to characterize cell damage caused by vaginal Candida albicans isolates from women with different symptomatologies. It was evaluated 12 clinical isolates of C. albicans from vaginal samples: 4 from asymptomatic women (AS), 4 from women with a single episode of vulvovaginal candidiasis (VVC) and 4 from women with recurrent vulvovaginal candidiasis (RVVC). We evaluated the ability of C. albicans to adhere to human cervical cancer cells (SiHa), the yeast-SiHa cell interactions and cell damage. All of the clinical isolates presented a high adhesion capacity on SiHa cells. However, clinical isolates from symptomatic women (VVC and RVVC) had higher filamentation after contact (24 h) with SiHa cells and a greater capacity to cause cell damage (>80 %). Clinical isolates from symptomatic women had greater potential to invade SiHa cells, suggesting that they are more pathogenic than AS isolates.

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

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    Jeanette Wagener

    Full Text Available 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 highly branched N-glycosylation residues. Moreover, these glycan moieties induce growth arrest and apoptosis of epithelial cells. Using an in vitro model of oral candidosis we demonstrate, that apoptosis induction by C. albicans wild-type occurs in early stage of infection and strongly depends on intact cell wall protein glycosylation. These novel findings demonstrate that glycosylation of the C. albicans cell wall proteins appears essential for modulation of epithelial immunity and apoptosis induction, both of which may promote fungal pathogenesis in vivo.

  4. Cell wall damage and oxidative stress in Candida albicans ATCC10231 and Aspergillus niger caused by palladium nanoparticles.

    Science.gov (United States)

    Athie-García, Martha Samira; Piñón-Castillo, Hilda Amelia; Muñoz-Castellanos, Laila Nayzzel; Ulloa-Ogaz, Ana Laura; Martínez-Varela, Perla Ivonne; Quintero-Ramos, Armando; Duran, Robert; Murillo-Ramirez, José Guadalupe; Orrantia-Borunda, Erasmo

    2018-04-01

    In this work the toxic effect of Palladium nanoparticles (PdNPs) was investigated in two eukaryotic cell models, Candida albicans and Aspergillus niger. PdNPs were synthesized by chemical reduction method, obtaining spherical NPs with a primary size ranging from 3 to 15 nm. PdNPs showed a hydrodynamic size of 1548 nm in Lee's minimum media. Minimal inhibitory concentration was determined at 200 and 250 ppm for Candida albicans and Aspergillus niger respectively, revealing a significant cell growth inhibition (ANOVA and tukey analysis, α = 0.5). Reactive Oxygen Species levels were increased in both microorganisms. Confocal, scanning and transmission electron microscopy studies revealed cell wall damage and cellular morphology changes, induced by the interaction of PdNPs, in both microorganisms. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. 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.

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

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    Li Tao

    2014-10-01

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

  7. Defective IL-17- and IL-22-dependent mucosal host response to Candida albicans determines susceptibility to oral candidiasis in mice expressing the HIV-1 transgene.

    Science.gov (United States)

    Goupil, Mathieu; Cousineau-Côté, Vincent; Aumont, Francine; Sénéchal, Serge; Gaboury, Louis; Hanna, Zaher; Jolicoeur, Paul; de Repentigny, Louis

    2014-10-26

    The tissue-signaling cytokines IL-17 and IL-22 are critical to host defense against oral Candida albicans infection, by their induction of oral antimicrobial peptide expression and recruitment of neutrophils. Mucosal Th17 cells which produce these cytokines are preferentially depleted in HIV-infected patients. Here, we tested the hypothesis that defective IL-17- and IL-22-dependent host responses to C. albicans determine the phenotype of susceptibility to oropharyngeal candidiasis (OPC) in transgenic (Tg) mice expressing HIV-1. Naïve CD4+ T-cells and the differentiated Th1, Th2, Th17, Th1Th17 and Treg lineages were all profoundly depleted in cervical lymph nodes (CLNs) of these Tg mice. However, naive CD4+ cells from Tg mice maintained the capacity to differentiate into these lineages in response to polarizing cytokines in vitro. Expression of Il17, Il22, S100a8 and Ccl20 was enhanced in oral mucosal tissue of non-Tg, but not of Tg mice, after oral infection with C. albicans. Treatment of infected Tg mice with the combination of IL-17 and IL-22, but not IL-17 or Il-22 alone, significantly reduced oral burdens of C. albicans and abundance of Candida hyphae in the epithelium of tongues of infected Tg mice, and restored the ability of the Tg mice to up-regulate expression of S100a8 and Ccl20 in response to C. albicans infection. These findings demonstrate that defective IL-17- and IL-22-dependent induction of innate mucosal immunity to C. albicans is central to the phenotype of susceptibility to OPC in these HIV transgenic mice.

  8. The Mkk2 MAPKK Regulates Cell Wall Biogenesis in Cooperation with the Cek1-Pathway in Candida albicans

    NARCIS (Netherlands)

    Román, Elvira; Alonso-Monge, Rebeca; Miranda Bedate, A.; Pla, Jesús

    2015-01-01

    The cell wall integrity pathway (CWI) plays an important role in the biogenesis of the cell wall in Candida albicans and other fungi. In the present work, the C. albicans MKK2 gene that encodes the putative MAPKK of this pathway was deleted in different backgrounds and the phenotypes of the

  9. Soluble factors from biofilm of Candida albicans and Staphylococcus aureus promote cell death and inflammatory response.

    Science.gov (United States)

    de Carvalho Dias, Kassia; Barbugli, Paula Aboud; de Patto, Fernanda; Lordello, Virginia Barreto; de Aquino Penteado, Letícia; Medeiros, Alexandra Ivo; Vergani, Carlos Eduardo

    2017-06-30

    The objective of this study was to better understand the effects of soluble factors from biofilm of single- and mixed-species Candida albicans (C. albicans) and methicillin-sensitive Staphylococcus aureus (MSSA) cultures after 36 h in culture on keratinocytes (NOK-si and HaCaT) and macrophages (J774A.1). Soluble factors from biofilms of C. albicans and MSSA were collected and incubated with keratinocytes and macrophages, which were subsequently evaluated by cell viability assays (MTT). Lactate dehydrogenase (LDH) enzyme release was measured to assess cell membrane damage to keratinocytes. Cells were analysed by brightfield microscopy after 2 and 24 h of exposure to the soluble factors from biofilm. Cell death was detected by labelling apoptotic cells with annexin V and necrotic cells with propidium iodide (PI) and was visualized via fluorescence microscopy. Soluble factors from biofilm were incubated with J774A.1 cells for 24 h; the subsequent production of NO and the cytokines IL-6 and TNF-α was measured by ELISA. The cell viability assays showed that the soluble factors of single-species C. albicans cultures were as toxic as the soluble factors from biofilm of mixed cultures, whereas the soluble factors of MSSA cultures were less toxic than those of C. albicans or mixed cultures. The soluble factors from biofilm of mixed cultures were the most toxic to the NOK-si and HaCaT cells, as confirmed by analyses of PI labelling and cell morphology. Soluble factors from biofilm of single-species MSSA and mixed-species cultures induced the production of IL-6, NO and TNF-α by J744A.1 macrophages. The production of IL-6 and NO induced by the soluble factors from biofilm of mixed cultures was lower than that induced by the soluble factors from biofilm of single-species MSSA cultures, whereas the soluble factors from biofilm of C. albicans cultures induced only low levels of NO. Soluble factors from 36-h-old biofilm of C. albicans and MSSA cultures promoted cell death and

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

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    Xiao-Xi Niu

    2017-01-01

    Conclusions: L. crispatus can attenuate the virulence of C. albicans, modulate the secretion of cytokines and chemokines, and enhance the immune response of VK2/E6E7 cells in vitro. The vaginal mucosa has a potential function in the local immune responses against pathogens that can be promoted by L. crispatus.

  11. Role of the Candida albicans MNN1 gene family in cell wall structure and virulence

    NARCIS (Netherlands)

    Bates, S.; Hall, R.A.; Cheetham, J.; Netea, M.G.; MacCallum, D.M.; Brown, A.J.; Odds, F.C.; Gow, N.A.

    2013-01-01

    BACKGROUND: The Candida albicans cell wall is the first point of contact with the host, and its outer surface is heavily enriched in mannoproteins modified through the addition of N- and O-mannan. Previous work, using mutants with gross defects in glycosylation, has clearly identified the importance

  12. 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.

  13. Characteristics of DTH suppressor cells in mice infected with Candida albicans.

    Science.gov (United States)

    Valdez, J C; Mesón, O E; Sirena, A; de Alderete, N G

    1987-05-01

    Inoculation of 10(8) C. albicans intraperitoneally into Balb/c mice at given dosage was reported to induce suppression of antigen-specific delayed-type hypersensitivity. Adoptive transfer of spleen cells into normal syngeneic mice pre-treated with Cyclophosphamide confirmed the existence of suppressor cells in mice. Such cells were sensitive to treatment with anti-theta serum and complement, non-adherent to Sephadex G-10. A pretreatment of the mice with Cyclophosphamide eliminated DTH suppression. Treatment with antimacrophage agents via intraperitoneal abrogated suppression only if being effected before inoculation of alive 10(8) Candida albicans. It is concluded that the spleen suppressor cell is a T-lymphocyte whose precursor is Cyclophosphamide-sensitive, requiring the macrophage to be induced.

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

    Science.gov (United States)

    Monteiro, D R; Gorup, L F; Silva, S; Negri, M; de Camargo, E R; Oliveira, R; Barbosa, D B; Henriques, M

    2011-08-01

    The aim of this study was to evaluate the effect of silver nanoparticles (SN) against Candida albicans and Candida glabrata adhered cells and biofilms. SN (average diameter 5 nm) were synthesized by silver nitrate reduction with sodium citrate and stabilized with ammonia. Minimal inhibitory concentration (MIC) tests were performed for C. albicans (n = 2) and C. glabrata (n = 2) grown in suspension following the Clinical Laboratory Standards Institute microbroth dilution method. SN were applied to adhered cells (2 h) or biofilms (48 h) and after 24 h of contact their effect was assessed by enumeration of colony forming units (CFUs) and quantification of total biomass (by crystal violet staining). The MIC results showed that SN were fungicidal against all strains tested at very low concentrations (0.4-3.3 μg ml(-1)). Furthermore, SN were more effective in reducing biofilm biomass when applied to adhered cells (2 h) than to pre-formed biofilms (48 h), with the exception of C. glabrata ATCC, which in both cases showed a reduction ∼90%. Regarding cell viability, SN were highly effective on adhered C. glabrata and respective biofilms. On C. albicans the effect was not so evident but there was also a reduction in the number of viable biofilm cells. In summary, SN may have the potential to be an effective alternative to conventional antifungal agents for future therapies in Candida-associated denture stomatitis.

  15. 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

  16. Binding of Candida albicans to Human CEACAM1 and CEACAM6 Modulates the Inflammatory Response of Intestinal Epithelial Cells

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    Esther Klaile

    2017-03-01

    Full Text Available Candida albicans colonizes human mucosa, including the gastrointestinal tract, as a commensal. In immunocompromised patients, C. albicans can breach the intestinal epithelial barrier and cause fatal invasive infections. Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1; CD66a, CEACAM5 (CEA, and CEACAM6 (CD66c are immunomodulatory receptors expressed on human mucosa and are recruited by bacterial and viral pathogens. Here we show for the first time that a fungal pathogen (i.e., C. albicans also binds directly to the extracellular domain of human CEACAM1, CEACAM3, CEACAM5, and CEACAM6. Binding was specific for human CEACAMs and mediated by the N-terminal IgV-like domain. In enterocytic C2BBe1 cells, C. albicans caused a transient tyrosine phosphorylation of CEACAM1 and induced higher expression of membrane-bound CEACAM1 and soluble CEACAM6. Lack of the CEACAM1 receptor after short hairpin RNA (shRNA knockdown abolished CXCL8 (interleukin-8 secretion by C2BBe1 cells in response to C. albicans. In CEACAM1-competent cells, the addition of recombinant soluble CEACAM6 reduced the C. albicans-induced CXCL8 secretion.

  17. [Effects of non-saccharomyces albicans metabolic products on the proliferation of human umbilical vein endothelial cell ECV304].

    Science.gov (United States)

    Chen, Bin; Che, Tuanjie; Bai, Decheng; He, Xiangyi

    2013-04-01

    To evaluate the effects of non-Saccharomyces albicans metabolic products on the cell cycle distribution and proliferation of human umbilical vein endothelial cell ECV304 cells in vitro. The parallel dilution supernatant of Saccharomyces tropicalis, Saccharomyces krusei and Saccharomyces glabrata were prepared, and 1, 4, 16-fold(s) diluted concentration and control group were set up. The line of human umbilical vein endothelial cell ECV304 was cultured in vitro and treated by non-Saccharomyces albicans supernatant. The proliferous effect of ECV304 induced by non-Saccharomyces albicans supernatant after 24, 48, 72 h was detected by the methods of MTT, and the changes of cell density and cycle after 48 h were investigated by inverted microscope and flow cytometry. At the 24th hour, all of the higher concentration (1-fold) of non-Saccharomyces albicans supernatant and the 4-folds diluted Saccharomyces krusei could promote ECV304 proliferation(P Saccharomyces albicans supernatant at 48h and 72th hour, Saccharomyces krusei supernatant and Saccharomyces glabrata supernatant significantly increased proliferation rate of ECV304, while Saccharomyces tropicalis supernatant group showed no significant change no matter which concentration was tested. At 48th hour after adding the non-Saccharomyces albicans supernatant, the ECV304 cells density treated by Saccharomyces krusei supernatant and Saccharomyces glabrata supernatant were significantly higher under the inverted microscope. The G0/G1 population of ECV304 cells decreased while cell proliferation index (PI) increased after incubated with Saccharomyces krusei supernatant and Saccharomyces glabrata supernatant for 48 hours (P Saccharomyces tropicalis group showed no significant change (P > 0.05). The metabolic products of Sacharoymces krusei and Saccharomyces glabrata could induce proliferation of ECV304 cell, which suggests non-Saccharomyces albicans should be undergone more attention clinically in detection and treatment.

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

    OpenAIRE

    Alvarez, Francisco J.; Douglas, Lois M.; Rosebrock, Adam; Konopka, James B.

    2008-01-01

    The Candida albicans plasma membrane plays important roles in cell growth and as a target for antifungal drugs. Analysis of Ca-Sur7 showed that this four transmembrane domain protein localized to stable punctate patches, similar to the plasma membrane subdomains known as eisosomes or MCC that were discovered in S. cerevisiae. The localization of Ca-Sur7 depended on sphingolipid synthesis. In contrast to S. cerevisiae, a C. albicans sur7Δ mutant displayed defects in endocytosis and morphogenes...

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  20. Cell Wall-Related Bionumbers and Bioestimates of Saccharomyces cerevisiae and Candida albicans

    Science.gov (United States)

    de Koster, Chris G.; Brul, Stanley

    2014-01-01

    Bionumbers and bioestimates are valuable tools in biological research. Here we focus on cell wall-related bionumbers and bioestimates of the budding yeast Saccharomyces cerevisiae and the polymorphic, pathogenic fungus Candida albicans. We discuss the linear relationship between cell size and cell ploidy, the correlation between cell size and specific growth rate, the effect of turgor pressure on cell size, and the reason why using fixed cells for measuring cellular dimensions can result in serious underestimation of in vivo values. We further consider the evidence that individual buds and hyphae grow linearly and that exponential growth of the population results from regular formation of new daughter cells and regular hyphal branching. Our calculations show that hyphal growth allows C. albicans to cover much larger distances per unit of time than the yeast mode of growth and that this is accompanied by strongly increased surface expansion rates. We therefore predict that the transcript levels of genes involved in wall formation increase during hyphal growth. Interestingly, wall proteins and polysaccharides seem barely, if at all, subject to turnover and replacement. A general lesson is how strongly most bionumbers and bioestimates depend on environmental conditions and genetic background, thus reemphasizing the importance of well-defined and carefully chosen culture conditions and experimental approaches. Finally, we propose that the numbers and estimates described here offer a solid starting point for similar studies of other cell compartments and other yeast species. PMID:24243791

  1. Biophysical Effects of a Polymeric Biosurfactant in Candida krusei and Candida albicans Cells.

    Science.gov (United States)

    Ferreira, Gabriella Freitas; Dos Santos Pinto, Bruna Lorrana; Souza, Eliene Batista; Viana, José Lima; Zagmignan, Adrielle; Dos Santos, Julliana Ribeiro Alves; Santos, Áquila Rodrigues Costa; Tavares, Priscila Batista; Denadai, Ângelo Márcio Leite; Monteiro, Andrea Souza

    2016-12-01

    This study evaluated the effects of a polymeric biosurfactant produced by Trichosporon montevideense CLOA72 in the adhesion of Candida albicans and Candida krusei cells to human buccal epithelial cells and its interference in biofilm formation by these strains. The biofilm inhibition by biosurfactant (25 mg/mL) in C. krusei and C. albicans in polystyrene was reduced up to 79.5 and 85 %, respectively. In addition, the zeta potential and hydrodynamic diameter of the yeasts altered as a function of the biosurfactant concentration added to the cell suspension. The changes in the cell surface characteristics and the interface modification can contribute to the inhibition of the initial adherence of yeasts cells to the surface. In addition, the analyses of the biofilm matrix and planktonic cell surfaces demonstrated differences in carbohydrate and protein concentrations for the two studied strains, which may contribute to the modulation of cell adhesion or consolidation of biofilms, especially in C. krusei. This study suggests a possible application of the of CLOA72 biosurfactant in inhibiting the adhesion and formation of biofilms on biological surfaces by yeasts of the Candida genus.

  2. Als3 is a Candida albicans invasin that binds to cadherins and induces endocytosis by host cells.

    Directory of Open Access Journals (Sweden)

    Quynh T Phan

    2007-03-01

    Full Text Available Candida albicans is the most common cause of hematogenously disseminated and oropharyngeal candidiasis. Both of these diseases are characterized by fungal invasion of host cells. Previously, we have found that C. albicans hyphae invade endothelial cells and oral epithelial cells in vitro by inducing their own endocytosis. Therefore, we set out to identify the fungal surface protein and host cell receptors that mediate this process. We found that the C. albicans Als3 is required for the organism to be endocytosed by human umbilical vein endothelial cells and two different human oral epithelial lines. Affinity purification experiments with wild-type and an als3delta/als3delta mutant strain of C. albicans demonstrated that Als3 was required for C. albicans to bind to multiple host cell surface proteins, including N-cadherin on endothelial cells and E-cadherin on oral epithelial cells. Furthermore, latex beads coated with the recombinant N-terminal portion of Als3 were endocytosed by Chinese hamster ovary cells expressing human N-cadherin or E-cadherin, whereas control beads coated with bovine serum albumin were not. Molecular modeling of the interactions of the N-terminal region of Als3 with the ectodomains of N-cadherin and E-cadherin indicated that the binding parameters of Als3 to either cadherin are similar to those of cadherin-cadherin binding. Therefore, Als3 is a fungal invasin that mimics host cell cadherins and induces endocytosis by binding to N-cadherin on endothelial cells and E-cadherin on oral epithelial cells. These results uncover the first known fungal invasin and provide evidence that C. albicans Als3 is a molecular mimic of human cadherins.

  3. Candida albicans induces Metabolic Reprogramming in human NK cells and responds to Perforin with a Zinc Depletion Response

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    Daniela eHellwig

    2016-05-01

    Full Text Available As part of the innate immune system, natural killer (NK cells are directly involved in the response to fungal infections. Perforin has been identified as the major effector molecule acting against many fungal pathogens. While several studies have shown that perforin mediated fungicidal effects can contribute to fungal clearance, neither the activation of NK cells by fungal pathogens nor the effects of perforin on fungal cells are well understood. In a dual approach, we have studied the global gene expression pattern of primary and cytokine activated NK cells after co-incubation with C. albicans and the transcriptomic adaptation of C. albicans to perforin exposure. NK cells responded to the fungal pathogen with an up-regulation of genes involved in immune signaling and release of cytokines. Furthermore, we observed a pronounced increase of genes involved in glycolysis and glycolysis inhibitor 2-deoxy-D-glucose impaired C. albicans induced NK cell activation. This strongly indicates that metabolic adaptation is a major part of the NK cell response to C. albicans infections. In the fungal pathogen, perforin induced a strong up-regulation of several fungal genes involved in the zinc depletion response, such as PRA1 and ZRT1. These data suggest that fungal zinc homeostasis is linked to the reaction to perforin secreted by NK cells. However, deletion mutants in PRA1 and ZRT1 did not show altered susceptibility to perforin.

  4. How to prevent contamination with Candida albicans during the fabrication of transplantable oral mucosal epithelial cell sheets

    Directory of Open Access Journals (Sweden)

    Ryo Takagi

    2015-06-01

    Full Text Available We have utilized patients' own oral mucosa as a cell source for the fabrication of transplantable epithelial cell sheets to treat limbal stem cell deficiency and mucosal defects after endoscopic submucosal dissection of esophageal cancer. Because there are abundant microbiotas in the human oral cavity, the oral mucosa was sterilized and 40 μg/mL gentamicin and 0.27 μg/mL amphotericin B were added to the culture medium in our protocol. Although an oral surgeon carefully checked each patient's oral cavity and although candidiasis was not observed before taking the biopsy, contamination with Candida albicans (C. albicans was detected in the conditioned medium during cell sheet fabrication. After adding 1 μg/mL amphotericin B to the transportation medium during transport from Nagasaki University Hospital to Tokyo Women's Medical University, which are 1200 km apart, no proliferation of C. albicans was observed. These results indicated that the supplementation of transportation medium with antimycotics would be useful for preventing contamination with C. albicans derived from the oral mucosa without hampering cell proliferation.

  5. Candida albicans: The Ability to Invade Epithelial Cells and Survive under Oxidative Stress Is Unlinked to Hyphal Length

    Directory of Open Access Journals (Sweden)

    Paloma K. Maza

    2017-07-01

    Full Text Available In its hyphal form, Candida albicans invades epithelial and endothelial cells by two distinct mechanisms: active penetration and induced endocytosis. The latter is dependent on a reorganization of the host cytoskeleton (actin/cortactin recruitment, whilst active penetration does not rely on the host's cellular machinery. The first obstacle for the fungus to reach deep tissues is the epithelial barrier and this interaction is crucial for commensal growth, fungal pathogenicity and host defense. This study aimed to characterize in vitro epithelial HeLa cell invasion by four different isolates of C. albicans with distinct clinical backgrounds, including a C. albicans SC5314 reference strain. All isolates invaded HeLa cells, recruited actin and cortactin, and induced the phosphorylation of both Src-family kinases (SFK and cortactin. Curiously, L3881 isolated from blood culture of a patient exhibited the highest resistance to oxidative stress, although this isolate showed reduced hyphal length and displayed the lowest cell damage and invasion rates. Collectively, these data suggest that the ability of C. albicans to invade HeLa cells, and to reach and adapt to the host's blood, including resistance to oxidative stress, may be independent of hyphal length.

  6. The external face of Candida albicans: A proteomic view of the cell surface and the extracellular environment.

    Science.gov (United States)

    Gil-Bona, Ana; Amador-García, Ahinara; Gil, Concha; Monteoliva, Lucia

    2018-05-30

    The cell surface and secreted proteins are the initial points of contact between Candida albicans and the host. Improvements in protein extraction approaches and mass spectrometers have allowed researchers to obtain a comprehensive knowledge of these external subproteomes. In this paper, we review the published proteomic studies that have examined C. albicans extracellular proteins, including the cell surface proteins or surfome and the secreted proteins or secretome. The use of different approaches to isolate cell wall and cell surface proteins, such as fractionation approaches or cell shaving, have resulted in different outcomes. Proteins with N-terminal signal peptide, known as classically secreted proteins, and those that lack the signal peptide, known as unconventionally secreted proteins, have been consistently identified. Existing studies on C. albicans extracellular vesicles reveal that they are relevant as an unconventional pathway of protein secretion and can help explain the presence of proteins without a signal peptide, including some moonlighting proteins, in the cell wall and the extracellular environment. According to the global view presented in this review, cell wall proteins, virulence factors such as adhesins or hydrolytic enzymes, metabolic enzymes and stress related-proteins are important groups of proteins in C. albicans surfome and secretome. Candida albicans extracellular proteins are involved in biofilm formation, cell nutrient acquisition and cell wall integrity maintenance. Furthermore, these proteins include virulence factors and immunogenic proteins. This review is of outstanding interest, not only because it extends knowledge of the C. albicans surface and extracellular proteins that could be related with pathogenesis, but also because it presents insights that may facilitate the future development of new antifungal drugs and vaccines and contributes to efforts to identify new biomarkers that can be employed to diagnose candidiasis

  7. Yeast casein kinase 2 governs morphology, biofilm formation, cell wall integrity, and host cell damage of Candida albicans.

    Science.gov (United States)

    Jung, Sook-In; Rodriguez, Natalie; Irrizary, Jihyun; Liboro, Karl; Bogarin, Thania; Macias, Marlene; Eivers, Edward; Porter, Edith; Filler, Scott G; Park, Hyunsook

    2017-01-01

    The regulatory networks governing morphogenesis of a pleomorphic fungus, Candida albicans are extremely complex and remain to be completely elucidated. This study investigated the function of C. albicans yeast casein kinase 2 (CaYck2p). The yck2Δ/yck2Δ strain displayed constitutive pseudohyphae in both yeast and hyphal growth conditions, and formed enhanced biofilm under non-biofilm inducing condition. This finding was further supported by gene expression analysis of the yck2Δ/yck2Δ strain which showed significant upregulation of UME6, a key transcriptional regulator of hyphal transition and biofilm formation, and cell wall protein genes ALS3, HWP1, and SUN41, all of which are associated with morphogenesis and biofilm architecture. The yck2Δ/yck2Δ strain was hypersensitive to cell wall damaging agents and had increased compensatory chitin deposition in the cell wall accompanied by an upregulation of the expression of the chitin synthase genes, CHS2, CHS3, and CHS8. Absence of CaYck2p also affected fungal-host interaction; the yck2Δ/yck2Δ strain had significantly reduced ability to damage host cells. However, the yck2Δ/yck2Δ strain had wild-type susceptibility to cyclosporine and FK506, suggesting that CaYck2p functions independently from the Ca+/calcineurin pathway. Thus, in C. albicans, Yck2p is a multifunctional kinase that governs morphogenesis, biofilm formation, cell wall integrity, and host cell interactions.

  8. Cell wall mannoprotein of Candida albicans induces cell cycle alternation and inhibits apoptosis of HaCaT cells via NF-κB signal pathway.

    Science.gov (United States)

    Han, Yang; Jiang, Hang-Hang; Zhang, Yu-Jing; Hao, Xing-Jia; Sun, Yu-Zhe; Qi, Rui-Qun; Chen, Hong-Duo; Gao, Xing-Hua

    2017-10-01

    Candida albicans (C. albicans) is a commensal organism in human and a well-known dimorphic opportunistic pathogenic fungus. Though plenty of researches on the pathogenesis of C. albicans have been performed, the mechanism is not fully understood. The cell wall components of C. albicans have been documented to play important roles in its pathogenic processes. To further study the infectious mechanism of C. albicans, we investigated the potential functional role of its cell wall mannoprotein in cell cycle and apoptosis of HaCaT cells. We found that mannoprotein could promote the transition of cell cycle from G1/G0 to S phase, in which Cyclin D1, CDK4 and p-Rb, the major regulators of the cell cycle progression, showed significant upregulation, and CDKN1A (cyclin dependent kinase inhibitor 1A (p21)) showed significant downregulation. Mannoprotein also could inhibit apoptosis of HaCaT cells, which was well associated with increased expression of BCL2 (Bcl-2). Moreover, mannoprotein could increase the phosphorylation levels of RELA (p65) and NFKBIA (IκBα), as the key factors of NF-κB signal pathway in HaCaT cells, suggesting the activation of NF-κB signal pathway. Additionally, a NF-κB specific inhibitor, PDTC, could rescue the effect of mannoprotein on cell cycle and apoptosis of HaCaT cells, which suggested that mannoprotein could activate NF-κB signal pathway to mediate cell cycle alternation and inhibit apoptosis. Copyright © 2017. Published by Elsevier Ltd.

  9. Targeted changes of the cell wall proteome influence Candida albicans ability to form single- and multi-strain biofilms.

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    Vitor Cabral

    2014-12-01

    Full Text Available Biofilm formation is an important virulence trait of the pathogenic yeast Candida albicans. We have combined gene overexpression, strain barcoding and microarray profiling to screen a library of 531 C. albicans conditional overexpression strains (∼10% of the genome for genes affecting biofilm development in mixed-population experiments. The overexpression of 16 genes increased strain occupancy within a multi-strain biofilm, whereas overexpression of 4 genes decreased it. The set of 16 genes was significantly enriched for those encoding predicted glycosylphosphatidylinositol (GPI-modified proteins, namely Ihd1/Pga36, Phr2, Pga15, Pga19, Pga22, Pga32, Pga37, Pga42 and Pga59; eight of which have been classified as pathogen-specific. Validation experiments using either individually- or competitively-grown overexpression strains revealed that the contribution of these genes to biofilm formation was variable and stage-specific. Deeper functional analysis of PGA59 and PGA22 at a single-cell resolution using atomic force microscopy showed that overexpression of either gene increased C. albicans ability to adhere to an abiotic substrate. However, unlike PGA59, PGA22 overexpression led to cell cluster formation that resulted in increased sensitivity to shear forces and decreased ability to form a single-strain biofilm. Within the multi-strain environment provided by the PGA22-non overexpressing cells, PGA22-overexpressing cells were protected from shear forces and fitter for biofilm development. Ultrastructural analysis, genome-wide transcript profiling and phenotypic analyses in a heterologous context suggested that PGA22 affects cell adherence through alteration of cell wall structure and/or function. Taken together, our findings reveal that several novel predicted GPI-modified proteins contribute to the cooperative behaviour between biofilm cells and are important participants during C. albicans biofilm formation. Moreover, they illustrate the power

  10. 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.

  11. 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.

  12. The cell wall protein Ecm33 of Candida albicans is involved in chronological life span, morphogenesis, cell wall regeneration, stress tolerance and host-cell interaction

    Directory of Open Access Journals (Sweden)

    Ana eGil-Bona

    2016-02-01

    Full Text Available Ecm33 is a glycosylphosphatidylinositol (GPI-anchored protein in the human pathogen Candida albicans. This protein is known to be involved in fungal cell wall integrity 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 cell wall integrity 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.

  13. 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.

  14. 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

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

    Science.gov (United States)

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

    2014-11-01

    Candida albicans is an important opportunistic pathogen, causing both superficial mucosal infections and life-threatening systemic diseases. Iron acquisition is an important factor for pathogen-host interaction and also a significant element for the pathogenicity of this organism. Ferric reductases, which convert ferric iron into ferrous iron, are important components of the high-affinity iron uptake system. Sequence analyses have identified at least 17 putative ferric reductase genes in C. albicans genome. CFL1 was the first ferric reductase identified in C. albicans. However, little is known about its roles in C. albicans physiology and pathogenicity. In this study, we found that disruption of CFL1 led to hypersensitivity to chemical and physical cell wall stresses, activation of the cell wall integrity (CWI) pathway, abnormal cell wall composition, and enhanced secretion, indicating a defect in CWI in this mutant. Moreover, this mutant showed abnormal mitochondrial activity and morphology, suggesting a link between ferric reductases and mitochondrial function. In addition, this mutant displayed decreased ability of adhesion to both the polystyrene microplates and buccal epithelial cells and invasion of host epithelial cells. These findings revealed a novel role of C. albicans Cfl1 in maintenance of CWI, mitochondrial function, and interaction between this pathogen and the host. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Cobb, S.J.; Parratt, D.

    1978-01-01

    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)

  17. Bst1 is required for Candida albicans infecting host via facilitating cell wall anchorage of Glycosylphosphatidyl inositol anchored proteins

    Science.gov (United States)

    Liu, Wei; Zou, Zui; Huang, Xin; Shen, Hui; He, Li Juan; Chen, Si Min; Li, Li Ping; Yan, Lan; Zhang, Shi Qun; Zhang, Jun Dong; Xu, Zheng; Xu, Guo Tong; An, Mao Mao; Jiang, Yuan Ying

    2016-01-01

    Glycosylphosphatidyl inositol anchored proteins (GPI-APs) on fungal cell wall are essential for invasive infections. While the function of inositol deacylation of GPI-APs in mammalian cells has been previously characterized the impact of inositol deacylation in fungi and implications to host infection remains largely unexplored. Herein we describe our identification of BST1, an inositol deacylase of GPI-Aps in Candida albicans, was critical for GPI-APs cell wall attachment and host infection. BST1-deficient C. albicans (bst1Δ/Δ) was associated with severely impaired cell wall anchorage of GPI-APs and subsequen unmasked β-(1,3)-glucan. Consistent with the aberrant cell wall structures, bst1Δ/Δ strain did not display an invasive ability and could be recognized more efficiently by host immune systems. Moreover, BST1 null mutants or those expressing Bst1 variants did not display inositol deacylation activity and exhibited severely attenuated virulence and reduced organic colonization in a murine systemic candidiasis model. Thus, Bst1 can facilitate cell wall anchorage of GPI-APs in C. albicans by inositol deacylation, and is critical for host invasion and immune escape. PMID:27708385

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

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    Máté Manczinger

    2015-01-01

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

  19. 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; 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

  20. The Mkk2 MAPKK Regulates Cell Wall Biogenesis in Cooperation with the Cek1-Pathway in Candida albicans.

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    Elvira Román

    Full Text Available The cell wall integrity pathway (CWI plays an important role in the biogenesis of the cell wall in Candida albicans and other fungi. In the present work, the C. albicans MKK2 gene that encodes the putative MAPKK of this pathway was deleted in different backgrounds and the phenotypes of the resultant mutants were characterised. We show here that Mkk2 mediates the phosphorylation of the Mkc1 MAPK in response to cell wall assembly interfering agents such as zymolyase or tunicamycin and also to oxidative stress. Remarkably, mkk2 and mkc1 mutants display related but distinguishable- cell wall associated phenotypes and differ in the pattern of MAPK phosphorylation under different stress conditions. mkk2 and mkc1 mutants display an altered expression of GSC1, CEK1 and CRH11 genes at different temperatures. Combined deletion of MKK2 with HST7 supports a cooperative role for the Cek1-mediated and CWI pathways in regulating cell wall architecture under vegetative growth. However, and in contrast to Mkc1, Mkk2 does not seem to play a role in the virulence of C. albicans in the mouse systemic model or the Galleria mellonella model of infection.

  1. Cell wall carbohydrates content of pathogenic Candida albicans strain morphological forms.

    Science.gov (United States)

    Staniszewska, Monika; Bondaryk, Małgorzata; Rabczenko, Daniel; Smoleńska-Sym, Gabriela; Kurzatkowski, Wiesław

    2013-01-01

    The study evaluated the cell wall carbohydrates fraction in blastoconidia grown in YEPD medium at 30 degrees C and in the conglomerate of true hyphae grown in human serum at 37 degrees C. The clinical isolate obtained from a child with widespread C. albicans infection was used in the study. The cells were broken with glass beads, centrifuged to harvest the cell wall followed by subjection to TFA hydrolysis and in the result of that released monosaccharides were detected by HPAEC-PAD. Both, serum and temperature conditions (37 degrees C) affected germination process influencing the cell wall carbohydrates content when incubation in serum was prolonged from 1 to 18 h. The mannan content of blastoconidia was almost twofold higher compared to filamentous forms (149.25 +/- 299.24 vs 77.26 +/- 122.07). The glucan content was threefold lower in blastoconidia compared to hyphae (251.86 +/- 243.44 vs 755.81 +/- 1299.30). The chitin level was fourfold lower in blastoconidia compared to filaments (23.86 +/- 54.09 vs 106.29 +/- 170.12). The reason for the differences in the carbohydrates content may be related to type of morphology induced in different environmental conditions. Among tested carbohydrates, glucan appeared to be present in appreciably larger amounts in both tested morphological fractions. The ultrastructure of the blastoconidial cell wall revealed striking differences compared to the hyphae indicating the carbohydrates content alterations for wall assembly during hyphal growth at alkaline pH and temp. 37 degrees C. The study provided evidence for the relationship between morphogenesis, cell-cell adhesion induced by serum and changes in the level of carbohydrates content.

  2. Mechanistic insight of the photodynamic effect induced by tri- and tetra-cationic porphyrins on Candida albicans cells.

    Science.gov (United States)

    Cormick, M Paula; Quiroga, Ezequiel D; Bertolotti, Sonia G; Alvarez, M Gabriela; Durantini, Edgardo N

    2011-10-01

    The photodynamic mechanism of action induced 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 on Candida albicans cells. These cationic porphyrins are effective photosensitizers, producing a ~5 log decrease of cell survival when the cultures are incubated with 5 μM photosensitizer and irradiated for 30 min with visible light. Studies under anoxic conditions indicated that oxygen is necessary for the mechanism of action of photodynamic inactivation of this yeast. Furthermore, photoinactivation of C. albicans cells was negligible in the presence of 100 mM azide ion, whereas the photocytotoxicity induced by these porphyrins increased in D(2)O. In contrast, the addition of 100 mM mannitol produced a negligible effect on the cellular phototoxicity. On the other hand, in vitro direct observation of singlet molecular oxygen, O(2)((1)Δ(g)) phosphorescence at 1270 nm was analyzed using C. albicans in D(2)O. A shorter lifetime of O(2)((1)Δ(g)) was found in yeast cellular suspensions. These cationic porphyrins bind strongly to C. albicans cells and the O(2)((1)Δ(g)) generated inside the cells is rapidly quenched by the biomolecules of the cellular microenvironment. Therefore, the results indicate that these cationic porphyrins appear to act as photosensitizers mainly via the intermediacy of O(2)((1)Δ(g)). This journal is © The Royal Society of Chemistry and Owner Societies 2011

  3. 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.

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

    Science.gov (United States)

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

    2010-06-01

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

  5. 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-β-glucan, a cell wall component that can stimulate phagocytes. To determine whether surface 1,3-β-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-β-glucan exposure. Caspofungin-treated C. albicans was fully able to suppress ROS production, indicating that suppression of ROS overrides stimulatory signals from 1,3-β-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

  6. 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

  7. The Sur7 protein regulates plasma membrane organization and prevents intracellular cell wall growth in Candida albicans.

    Science.gov (United States)

    Alvarez, Francisco J; Douglas, Lois M; Rosebrock, Adam; Konopka, James B

    2008-12-01

    The Candida albicans plasma membrane plays important roles in cell growth and as a target for antifungal drugs. Analysis of Ca-Sur7 showed that this four transmembrane domain protein localized to stable punctate patches, similar to the plasma membrane subdomains known as eisosomes or MCC that were discovered in S. cerevisiae. The localization of Ca-Sur7 depended on sphingolipid synthesis. In contrast to S. cerevisiae, a C. albicans sur7Delta mutant displayed defects in endocytosis and morphogenesis. Septins and actin were mislocalized, and cell wall synthesis was very abnormal, including long projections of cell wall into the cytoplasm. Several phenotypes of the sur7Delta mutant are similar to the effects of inhibiting beta-glucan synthase, suggesting that the abnormal cell wall synthesis is related to activation of chitin synthase activity seen under stress conditions. These results expand the roles of eisosomes by demonstrating that Sur7 is needed for proper plasma membrane organization and cell wall synthesis. A conserved Cys motif in the first extracellular loop of fungal Sur7 proteins is similar to a characteristic motif of the claudin proteins that form tight junctions in animal cells, suggesting a common role for these tetraspanning membrane proteins in forming specialized plasma membrane domains.

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

    Science.gov (United States)

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

    2008-01-01

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

  9. 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.

  10. Oral-resident natural Th17 cells and γδ T cells control opportunistic Candida albicans infections.

    Science.gov (United States)

    Conti, Heather R; Peterson, Alanna C; Brane, Lucas; Huppler, Anna R; Hernández-Santos, Nydiaris; Whibley, Natasha; Garg, Abhishek V; Simpson-Abelson, Michelle R; Gibson, Gregory A; Mamo, Anna J; Osborne, Lisa C; Bishu, Shrinivas; Ghilardi, Nico; Siebenlist, Ulrich; Watkins, Simon C; Artis, David; McGeachy, Mandy J; Gaffen, Sarah L

    2014-09-22

    Oropharyngeal candidiasis (OPC) is an opportunistic fungal infection caused by Candida albicans. OPC is frequent in HIV/AIDS, implicating adaptive immunity. Mice are naive to Candida, yet IL-17 is induced within 24 h of infection, and susceptibility is strongly dependent on IL-17R signaling. We sought to identify the source of IL-17 during the early innate response to candidiasis. We show that innate responses to Candida require an intact TCR, as SCID, IL-7Rα(-/-), and Rag1(-/-) mice were susceptible to OPC, and blockade of TCR signaling by cyclosporine induced susceptibility. Using fate-tracking IL-17 reporter mice, we found that IL-17 is produced within 1-2 d by tongue-resident populations of γδ T cells and CD3(+)CD4(+)CD44(hi)TCRβ(+)CCR6(+) natural Th17 (nTh17) cells, but not by TCR-deficient innate lymphoid cells (ILCs) or NK cells. These cells function redundantly, as TCR-β(-/-) and TCR-δ(-/-) mice were both resistant to OPC. Whereas γδ T cells were previously shown to produce IL-17 during dermal candidiasis and are known to mediate host defense at mucosal surfaces, nTh17 cells are poorly understood. The oral nTh17 population expanded rapidly after OPC, exhibited high TCR-β clonal diversity, and was absent in Rag1(-/-), IL-7Rα(-/-), and germ-free mice. These findings indicate that nTh17 and γδ T cells, but not ILCs, are key mucosal sentinels that control oral pathogens. © 2014 Conti et al.

  11. Exposure to Candida albicans polarizes a T-cell driven arthritis model towards Th17 responses, resulting in a more destructive arthritis.

    Science.gov (United States)

    Marijnissen, Renoud J; Koenders, Marije I; van de Veerdonk, Frank L; Dulos, John; Netea, Mihai G; Boots, Annemieke M H; Joosten, Leo A B; van den Berg, Wim B

    2012-01-01

    Fungal components have been shown very effective in generating Th17 responses. We investigated whether exposure to a minute amount of C. albicans in the arthritic joint altered the local cytokine environment, leading to enhanced Th17 expansion and resulting in a more destructive arthritis. Chronic SCW arthritis was induced by repeated injection with Streptococcus pyogenes (SCW) cell wall fragments into the knee joint of C57Bl/6 mice, alone or in combination with the yeast of C. albicans or Zymosan A. During the chronic phase of the arthritis, the cytokine levels, mRNA expression and histopathological analysis of the joints were performed. To investigate the phenotype of the IL-17 producing T-cells, synovial cells were isolated and analyzed by flowcytometry. Intra-articular injection of either Zymosan A or C. albicans on top of the SCW injection both resulted in enhanced joint swelling and inflammation compared to the normal SCW group. However, only the addition of C. albicans during SCW arthritis resulted in severe chondrocyte death and enhanced destruction of cartilage and bone. Additionally, exposure to C. albicans led to increased IL-17 in the arthritic joint, which was accompanied by an increased synovial mRNA expression of T-bet and RORγT. Moreover, the C. albicans-injected mice had significantly more Th17 cells in the synovium, of which a large population also produced IFN-γ. This study clearly shows that minute amounts of fungal components, like C. albicans, are very potent in interfering with the local cytokine environment in an arthritic joint, thereby polarizing arthritis towards a more destructive phenotype.

  12. Vaginal epithelial cell-derived S100 alarmins induced by Candida albicans via pattern recognition receptor interactions are sufficient but not necessary for the acute neutrophil response during experimental vaginal candidiasis.

    Science.gov (United States)

    Yano, Junko; Palmer, Glen E; Eberle, Karen E; Peters, Brian M; Vogl, Thomas; McKenzie, Andrew N; Fidel, Paul L

    2014-02-01

    Vulvovaginal candidiasis (VVC), caused by Candida albicans, affects women worldwide. Animal and clinical studies suggest that the immunopathogenic inflammatory condition of VVC is initiated by S100 alarmins in response to C. albicans, which stimulate polymorphonuclear neutrophil (PMN) migration to the vagina. The purpose of this study was to extend previous in vitro data and determine the requirement for the alarmin S100A8 in the PMN response and to evaluate pattern recognition receptors (PRRs) that initiate the response. For the former, PMN migration was evaluated in vitro or in vivo in the presence or absence of S100 alarmins initiated by several approaches. For the latter, vaginal epithelial cells were evaluated for PRR expression and C. albicans-induced S100A8 and S100A9 mRNAs, followed by evaluation of the PMN response in inoculated PRR-deficient mice. Results revealed that, consistent with previously reported in vitro data, eukaryote-derived S100A8, but not prokaryote-derived recombinant S100A8, induced significant PMN chemotaxis in vivo. Conversely, a lack of biologically active S100A8 alarmin, achieved by antibody neutralization or by using S100A9(-/-) mice, had no effect on the PMN response in vivo. In PRR analyses, whereas Toll-like receptor 4 (TLR4)- and SIGNR1-deficient vaginal epithelial cells showed a dramatic reduction in C. albicans-induced S100A8/S100A9 mRNAs in vitro, inoculated mice deficient in these PRRs showed PMN migration similar to that in wild-type controls. These results suggest that S100A8 alarmin is sufficient, but not necessary, to induce PMN migration during VVC and that the vaginal PMN response to C. albicans involves PRRs in addition to SIGNR1 and TLR4, or other induction pathways.

  13. Adaptation of Candida albicans to environmental pH induces cell wall remodelling and enhances innate immune recognition.

    Directory of Open Access Journals (Sweden)

    Sarah L Sherrington

    2017-05-01

    Full Text Available Candida albicans is able to proliferate in environments that vary dramatically in ambient pH, a trait required for colonising niches such as the stomach, vaginal mucosal and the GI tract. Here we show that growth in acidic environments involves cell wall remodelling which results in enhanced chitin and β-glucan exposure at the cell wall periphery. Unmasking of the underlying immuno-stimulatory β-glucan in acidic environments enhanced innate immune recognition of C. albicans by macrophages and neutrophils, and induced a stronger proinflammatory cytokine response, driven through the C-type lectin-like receptor, Dectin-1. This enhanced inflammatory response resulted in significant recruitment of neutrophils in an intraperitoneal model of infection, a hallmark of symptomatic vaginal colonisation. Enhanced chitin exposure resulted from reduced expression of the cell wall chitinase Cht2, via a Bcr1-Rim101 dependent signalling cascade, while increased β-glucan exposure was regulated via a non-canonical signalling pathway. We propose that this "unmasking" of the cell wall may induce non-protective hyper activation of the immune system during growth in acidic niches, and may attribute to symptomatic vaginal infection.

  14. Adaptation of Candida albicans to environmental pH induces cell wall remodelling and enhances innate immune recognition

    Science.gov (United States)

    Sorsby, Eleanor; Mahtey, Nabeel; Brown, Ian

    2017-01-01

    Candida albicans is able to proliferate in environments that vary dramatically in ambient pH, a trait required for colonising niches such as the stomach, vaginal mucosal and the GI tract. Here we show that growth in acidic environments involves cell wall remodelling which results in enhanced chitin and β-glucan exposure at the cell wall periphery. Unmasking of the underlying immuno-stimulatory β-glucan in acidic environments enhanced innate immune recognition of C. albicans by macrophages and neutrophils, and induced a stronger proinflammatory cytokine response, driven through the C-type lectin-like receptor, Dectin-1. This enhanced inflammatory response resulted in significant recruitment of neutrophils in an intraperitoneal model of infection, a hallmark of symptomatic vaginal colonisation. Enhanced chitin exposure resulted from reduced expression of the cell wall chitinase Cht2, via a Bcr1-Rim101 dependent signalling cascade, while increased β-glucan exposure was regulated via a non-canonical signalling pathway. We propose that this “unmasking” of the cell wall may induce non-protective hyper activation of the immune system during growth in acidic niches, and may attribute to symptomatic vaginal infection. PMID:28542528

  15. The Mitochondrial GTPase Gem1 Contributes to the Cell Wall Stress Response and Invasive Growth of Candida albicans

    Directory of Open Access Journals (Sweden)

    Barbara Koch

    2017-12-01

    Full Text Available The interactions of mitochondria with the endoplasmic reticulum (ER are crucial for maintaining proper mitochondrial morphology, function and dynamics. This enables cells to utilize their mitochondria optimally for energy production and anabolism, and it further provides for metabolic control over developmental decisions. In fungi, a key mechanism by which ER and mitochondria interact is via a membrane tether, the protein complex ERMES (ER-Mitochondria Encounter Structure. In the model yeast Saccharomyces cerevisiae, the mitochondrial GTPase Gem1 interacts with ERMES, and it has been proposed to regulate its activity. Here we report on the first characterization of Gem1 in a human fungal pathogen. We show that in Candida albicans Gem1 has a dominant role in ensuring proper mitochondrial morphology, and our data is consistent with Gem1 working with ERMES in this role. Mitochondrial respiration and steady state cellular phospholipid homeostasis are not impacted by inactivation of GEM1 in C. albicans. There are two major virulence-related consequences of disrupting mitochondrial morphology by GEM1 inactivation: C. albicans becomes hypersusceptible to cell wall stress, and is unable to grow invasively. In the gem1Δ/Δ mutant, it is specifically the invasive capacity of hyphae that is compromised, not the ability to transition from yeast to hyphal morphology, and this phenotype is shared with ERMES mutants. As a consequence of the hyphal invasion defect, the gem1Δ/Δ mutant is drastically hypovirulent in the worm infection model. Activation of the mitogen activated protein (MAP kinase Cek1 is reduced in the gem1Δ/Δ mutant, and this function could explain both the susceptibility to cell wall stress and lack of invasive growth. This result establishes a new, respiration-independent mechanism of mitochondrial control over stress signaling and hyphal functions in C. albicans. We propose that ER-mitochondria interactions and the ER

  16. The Mitochondrial GTPase Gem1 Contributes to the Cell Wall Stress Response and Invasive Growth of Candida albicans.

    Science.gov (United States)

    Koch, Barbara; Tucey, Timothy M; Lo, Tricia L; Novakovic, Stevan; Boag, Peter; Traven, Ana

    2017-01-01

    The interactions of mitochondria with the endoplasmic reticulum (ER) are crucial for maintaining proper mitochondrial morphology, function and dynamics. This enables cells to utilize their mitochondria optimally for energy production and anabolism, and it further provides for metabolic control over developmental decisions. In fungi, a key mechanism by which ER and mitochondria interact is via a membrane tether, the protein complex ERMES (ER-Mitochondria Encounter Structure). In the model yeast Saccharomyces cerevisiae , the mitochondrial GTPase Gem1 interacts with ERMES, and it has been proposed to regulate its activity. Here we report on the first characterization of Gem1 in a human fungal pathogen. We show that in Candida albicans Gem1 has a dominant role in ensuring proper mitochondrial morphology, and our data is consistent with Gem1 working with ERMES in this role. Mitochondrial respiration and steady state cellular phospholipid homeostasis are not impacted by inactivation of GEM1 in C. albicans . There are two major virulence-related consequences of disrupting mitochondrial morphology by GEM1 inactivation: C. albicans becomes hypersusceptible to cell wall stress, and is unable to grow invasively. In the gem1 Δ / Δ mutant, it is specifically the invasive capacity of hyphae that is compromised, not the ability to transition from yeast to hyphal morphology, and this phenotype is shared with ERMES mutants. As a consequence of the hyphal invasion defect, the gem1 Δ / Δ mutant is drastically hypovirulent in the worm infection model. Activation of the mitogen activated protein (MAP) kinase Cek1 is reduced in the gem1 Δ / Δ mutant, and this function could explain both the susceptibility to cell wall stress and lack of invasive growth. This result establishes a new, respiration-independent mechanism of mitochondrial control over stress signaling and hyphal functions in C. albicans . We propose that ER-mitochondria interactions and the ER-Mitochondria Organizing

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

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    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.

  18. The effect of Candida albicans on the expression levels of toll-like receptor 2 and interleukin-8 in HaCaT cells under High- and Low-glucose conditions

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    Di Wang

    2018-01-01

    Full Text Available Background: The diabetics are prone to skin infections, especially with Candida albicans. It is important to elucidate the different antifungal abilities of patients with hyperglycemia and healthy controls for the treatment of this condition. The toll-like receptor 2 (TLR2 and interleukin (IL-8 secreted by keratinocytes counteract C. albicans. Aim: This study aims to explore the differential expression of toll-like receptor 2 (TLR2 and interleukin (IL-8 secretion by keratinocytes between controls and diabetic patients when challenged with C. albicans. Materials and Methods: HaCaT cells were cultured in high-glucose (HG Dulbecco's modified Eagle's medium (DMEM and low-glucose (LG DMEM. Then, they were exposed to C. albicans hyphae for 24 h. The expression levels of TLR2 and IL-8 were determined at different periods in both the HG and LG groups. Real-time polymerase chain reaction analysis, western blotting, and enzyme-linked immunosorbent assays were performed in this study. The morphological changes of HaCaT cells under two different glucose concentrations were also observed. Results: We found that the expression levels of both TLR2 and IL-8 increased and then decreased in the two groups. Notably, the IL-8 levels in the LG group were higher than those in the HG group at each time point (P<0.05, and the TLR2 levels in the LG group were higher than those in the HG group at the beginning of the experiment and after 24 h of treatment with C. albicans (P<0.05. In each group, the levels of IL-8 and TLR2 at the secretion peak were significantly different from those in the initial and the last period of observation (P<0.05. The cellular morphology of HaCaT cells treated with different concentrations of glucose was also similar. However, with prolonged coculture time, cell death increased. Conclusion: These observations showed that TLR2 and IL-8 act on the keratinocytes interacting with C. albicans, and HG status might affect the function of HaCaT cells

  19. Interference with effects of amphotericin B on Candida albicans cells by 2-chloroethyl-1-nitrosoureas.

    OpenAIRE

    Brajtburg, J; Elberg, S; Kobayashi, G S; Medoff, G

    1988-01-01

    Two nitrosoureas, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) and 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU), with strong carbamoylating and weak alkylating activities, interfered with the induction of potassium leakage and lethal action of amphotericin B (AmB) on Candida albicans. 2-Cyclohexyl isocyanate, the product of decomposition of CCNU, and 2-chloroethyl isocyanate, the product of decomposition of BCNU, also interfered with the anticandidal actions of AmB. In contrast, two ni...

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

    Science.gov (United States)

    Nuryanti, Siti; Puspitasari, Dwi Juli

    2017-08-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2016-04-01

    Denture liners have physical properties that favour plaque accumulation and colonization by Candida species, irritating oral tissues and causing denture stomatitis. To isolate and determine the incidence of oral Candida species in dental prostheses, oral swabs were collected from the dental prostheses of 66 patients. All the strains were screened for their ability to form biofilms; both monospecies and dual-species combinations were tested. Candida albicans (63 %) was the most frequently isolated microorganism; Candida tropicalis (14 %), Candida glabrata (13 %), Candida rugosa (5 %), Candida parapsilosis (3 %), and Candida krusei (2 %) were also detected. The XTT assay showed that C. albicans SC5314 possessed a biofilm-forming ability significantly higher (p biofilm was less than the total CFU of a monospecies C. albicans biofilm. In contrast to the profuse hyphae verified in monospecies C. albicans biofilms, micrographies showed that the C. albicans/non-albicans Candida biofilms consisted of sparse yeast forms and profuse budding yeast cells that generated a network. These results suggested that C. albicans and the tested Candida species could co-exist in biofilms displaying apparent antagonism. The study provide the first description of C. albicans/C. rugosa mixed biofilm. Copyright © 2016 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  3. Endoplasmic reticulum-derived reactive oxygen species (ROS) is involved in toxicity of cell wall stress to Candida albicans.

    Science.gov (United States)

    Yu, Qilin; Zhang, Bing; Li, Jianrong; Zhang, Biao; Wang, Honggang; Li, Mingchun

    2016-10-01

    The cell wall is an important cell structure in both fungi and bacteria, and hence becomes a common antimicrobial target. The cell wall-perturbing agents disrupt synthesis and function of cell wall components, leading to cell wall stress and consequent cell death. However, little is known about the detailed mechanisms by which cell wall stress renders fungal cell death. In this study, we found that ROS scavengers drastically attenuated the antifungal effect of cell wall-perturbing agents to the model fungal pathogen Candida albicans, and these agents caused remarkable ROS accumulation and activation of oxidative stress response (OSR) in this fungus. Interestingly, cell wall stress did not cause mitochondrial dysfunction and elevation of mitochondrial superoxide levels. Furthermore, the iron chelator 2,2'-bipyridyl (BIP) and the hydroxyl radical scavengers could not attenuate cell wall stress-caused growth inhibition and ROS accumulation. However, cell wall stress up-regulated expression of unfold protein response (UPR) genes, enhanced protein secretion and promoted protein folding-related oxidation of Ero1, an important source of ROS production. These results indicated that oxidation of Ero1 in the endoplasmic reticulum (ER), rather than mitochondrial electron transport and Fenton reaction, contributed to cell wall stress-related ROS accumulation and consequent growth inhibition. Our findings uncover a novel link between cell wall integrity (CWI), ER function and ROS production in fungal cells, and shed novel light on development of strategies promoting the antifungal efficacy of cell wall-perturbing agents against fungal infections. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. 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

  5. Lactoferrin release and interleukin-1, interleukin-6, and tumor necrosis factor production by human polymorphonuclear cells stimulated by various lipopolysaccharides: relationship to growth inhibition of Candida albicans.

    OpenAIRE

    Palma, C; Cassone, A; Serbousek, D; Pearson, C A; Djeu, J Y

    1992-01-01

    Lipopolysaccharides (LPSs) from Escherichia coli, Serratia marcescens, and Salmonella typhimurium, at doses from 1 to 100 ng/ml, strongly enhanced growth inhibition of Candida albicans by human polymorphonuclear leukocytes (PMN) in vitro. Flow cytometry analysis demonstrated that LPS markedly augmented phagocytosis of Candida cells by increasing the number of yeasts ingested per neutrophil as well as the number of neutrophils capable of ingesting fungal cells. LPS activation caused augmented ...

  6. 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...

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

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    Bokor-Bratić Marija B.

    2008-01-01

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

  8. Use of green fluorescent protein fusions to analyse the N- and C-terminal signal peptides of GPI-anchored cell wall proteins in Candida albicans.

    Science.gov (United States)

    Mao, Yuxin; Zhang, Zimei; Wong, Brian

    2003-12-01

    Glycophosphatidylinositol (GPI)-anchored proteins account for 26-35% of the Candida albicans cell wall. To understand the signals that regulate these proteins' cell surface localization, green fluorescent protein (GFP) was fused to the N- and C-termini of the C. albicans cell wall proteins (CWPs) Hwp1p, Als3p and Rbt5p. C. albicans expressing all three fusion proteins were fluorescent at the cell surface. GFP was released from membrane fractions by PI-PLC and from cell walls by beta-glucanase, which implied that GFP was GPI-anchored to the plasma membrane and then covalently attached to cell wall glucans. Twenty and 25 amino acids, respectively, from the N- and C-termini of Hwp1p were sufficient to target GFP to the cell surface. C-terminal substitutions that are permitted by the omega rules (G613D, G613N, G613S, G613A, G615S) did not interfere with GFP localization, whereas some non-permitted substitutions (G613E, G613Q, G613R, G613T and G615Q) caused GFP to accumulate in intracellular ER-like structures and others (G615C, G613N/G615C and G613D/G615C) did not. These results imply that (i) GFP fusions can be used to analyse the N- and C-terminal signal peptides of GPI-anchored CWPs, (ii) the omega amino acid in Hwp1p is G613, and (iii) C can function at the omega+2 position in C. albicans GPI-anchored proteins.

  9. Killing of Candida albicans by Human Salivary Histatin 5 Is Modulated, but Not Determined, by the Potassium Channel TOK1

    OpenAIRE

    Baev, Didi; Rivetta, Alberto; Li, Xuewei S.; Vylkova, Slavena; Bashi, Esther; Slayman, Clifford L.; Edgerton, Mira

    2003-01-01

    Salivary histatin 5 (Hst 5), a potent toxin for the human fungal pathogen Candida albicans, induces noncytolytic efflux of cellular ATP, potassium, and magnesium in the absence of cytolysis, implicating these ion movements in the toxin's fungicidal activity. Hst 5 action on Candida resembles, in many respects, the action of the K1 killer toxin on Saccharomyces cerevisiae, and in that system the yeast plasma membrane potassium channel, Tok1p, has recently been reported to be a primary target o...

  10. Evaluation of adhesion forces of Staphylococcus aureus along the length of Candida albicans hyphae.

    Science.gov (United States)

    Ovchinnikova, Ekaterina S; Krom, Bastiaan P; Busscher, Henk J; van der Mei, Henny C

    2012-11-27

    Candida albicans is a human fungal pathogen, able to cause both superficial and serious, systemic diseases and is able to switch from yeast cells to long, tube-like hyphae, depending on the prevailing environmental conditions. Both morphological forms of C. albicans are found in infected tissue, often in combination with Staphylococcus aureus. Although bacterial adhesion to the different morphologies of C. albicans has been amply studied, possible differences in staphylococcal adhesion forces along the length of C. albicans hyphae have never been determined. In this study, we aim to verify the hypothesis that the forces mediating S. aureus NCTC8325-4GFP adhesion to hyphae vary along the length of C. albicans SC5314 and MB1 hyphae, as compared with adhesion to yeast cells. C. albicans hyphae were virtually divided into a "tip" (the growing and therefore youngest part of the hyphae), a "middle" and a so-called "head" region (the yeast cell from which germination started). Adhesion forces between S. aureus NCTC8325-4GFP and the different regions of C. albicans SC5314 hyphae were measured using atomic force microscopy. Strong adhesion forces were found at the tip and middle regions of C. albicans hyphae (-4.1 nN and -4.0 nN, respectively), while much smaller adhesion forces were measured at the head region (-0.3 nN). Adhesion forces exerted by the head region were comparable with the forces arising from budding yeast cells (-0.5 nN). A similar regional dependence of the staphylococcal adhesion forces was found for the clinical isolate involved in this study, C. albicans MB1. This is the first time that differences in adhesion forces between S. aureus and different regions of C. albicans hyphae have been demonstrated on a quantitative basis, supporting the view that the head region is different from the remainder of the hyphae. Notably it can be concluded that the properties of the hyphal head region are similar to those of budding yeast cells. These novel findings

  11. IL-9 and Mast Cells Are Key Players of Candida albicans Commensalism and Pathogenesis in the Gut.

    Science.gov (United States)

    Renga, Giorgia; Moretti, Silvia; Oikonomou, Vasilis; Borghi, Monica; Zelante, Teresa; Paolicelli, Giuseppe; Costantini, Claudio; De Zuani, Marco; Villella, Valeria Rachela; Raia, Valeria; Del Sordo, Rachele; Bartoli, Andrea; Baldoni, Monia; Renauld, Jean-Christophe; Sidoni, Angelo; Garaci, Enrico; Maiuri, Luigi; Pucillo, Carlo; Romani, Luigina

    2018-05-08

    Candida albicans is implicated in intestinal diseases. Identifying host signatures that discriminate between the pathogenic versus commensal nature of this human commensal is clinically relevant. In the present study, we identify IL-9 and mast cells (MCs) as key players of Candida commensalism and pathogenicity. By inducing TGF-β in stromal MCs, IL-9 pivotally contributes to mucosal immune tolerance via the indoleamine 2,3-dioxygenase enzyme. However, Candida-driven IL-9 and mucosal MCs also contribute to barrier function loss, dissemination, and inflammation in experimental leaky gut models and are upregulated in patients with celiac disease. Inflammatory dysbiosis occurs with IL-9 and MC deficiency, indicating that the activity of IL-9 and MCs may go beyond host immunity to include regulation of the microbiota. Thus, the output of the IL-9/MC axis is highly contextual during Candida colonization and reveals how host immunity and the microbiota finely tune Candida behavior in the gut. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  12. HIV-1 anti-retroviral drug effect on the C. albicans hyphal growth rate by a Bio-Cell Tracer system Efeito da droga anti-retroviral HIV-1 no crescimento de hifas de C. albicans monitoradas pelo sistema "Bio-Cell Tracer"

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    Nadja Rodrigues de Melo

    2006-09-01

    Full Text Available Declining incidence of oropharyngeal candidosis and opportunistic infections over recent years can be attributed to the use of highly active anti-retroviral therapy (HAART. Infection with C. albicans generally involves adherence and colonization of superficial tissues. During this process, budding yeasts are able to transform to hyphae and penetrate into the deep tissue. Using the biocell tracer system, C. albicans hyphal growth was dynamically observed at the cellular level. Ritonavir was effective in the inhibition of hyphal growth with growth rate of 0.8 mum/min. This study showed the in vitro effect of HIV anti-retroviral drug on the growth rate of the C. albicans hyphae.O declínio na incidência de candidose orofaríngea e infecções oportunistas associadas a infecção pelo HIV tem sido atribuído a introdução da terapia antiretroviral combinada (HAART. Infecção por C. albicans envolve aderência e colonização da mucosa superficial. Durante este processo leveduras são capazes de transformar-se na forma de hifas e penetrar nos tecidos mais profundos. Usando o sistema "Bio-Cell Tracer", o crescimento de hifas de C. albicans foi observado dinamicamente a nível celular. Ritonavir, inibidor de protease do HIV, foi efetivo na inibição do crescimento de hifas com media de 0.8 mim/min.O presente estudo demonstrou o efeito in vitro de um agente anti-retroviral HIV sobre o crescimento de hifas de C. albicans.

  13. In vitro studies on oxidative stress-independent, Ag nanoparticles-induced cell toxicity of Candida albicans, an opportunistic pathogen

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    Radhakrishnan VS

    2018-03-01

    Full Text Available Venkatraman Srinivasan Radhakrishnan,1 Surya Prakash Dwivedi,2 Mohammed Haris Siddiqui,3 Tulika Prasad1 1Advanced Instrumentation Research Facility (AIRF, Jawaharlal Nehru University, New Delhi, 2School of Biotechnology, IFTM University, Moradabad, 3Department of Bioengineering, Integral University, Lucknow, Uttar Pradesh, India Abstract: Silver nanoparticles (AgNps have attracted maximal attention among all metal nanoparticles, and the study of their biological properties has gained impetus for further medical adoption. This study evaluated the cellular and molecular mechanisms associated with the action of AgNps against an opportunistic pathogen, Candida albicans. Spherical, stable AgNp (average size 21.6 nm prepared by a chemical reduction method showed minimum inhibitory concentration (required to inhibit the growth of 90% of organisms at 40 µg/mL. AgNps have been reported to induce oxidative stress-mediated programmed cell death through the accumulation of intracellular reactive oxygen species (ROS. However, this study demonstrated that intracellular levels of AgNp-induced ROS could be reversed by using antioxidant ascorbic acid, but the sensitivity of AgNp-treated Candida cells could not be completely reversed. Moreover, in addition to the generation of ROS, the AgNps were found to affect other cellular targets resulting in altered membrane fluidity, membrane microenvironment, ergosterol content, cellular morphology, and ultrastructure. Thus, the generation of ROS does not seem to be the sole major cause of AgNp-mediated cell toxicity in Candida. Rather, the multitargeted action of AgNps, generation of ROS, alterations in ergosterol content, and membrane fluidity together seem to have potentiated anti-Candida action. Thus, this “nano-based drug therapy” is likely to favor broad-spectrum activity, multiple cellular targets, and minimum host toxicity. AgNps, therefore, appear to have the potential to address the challenges in multidrug

  14. Lactoferrin release and interleukin-1, interleukin-6, and tumor necrosis factor production by human polymorphonuclear cells stimulated by various lipopolysaccharides: relationship to growth inhibition of Candida albicans.

    Science.gov (United States)

    Palma, C; Cassone, A; Serbousek, D; Pearson, C A; Djeu, J Y

    1992-11-01

    Lipopolysaccharides (LPSs) from Escherichia coli, Serratia marcescens, and Salmonella typhimurium, at doses from 1 to 100 ng/ml, strongly enhanced growth inhibition of Candida albicans by human polymorphonuclear leukocytes (PMN) in vitro. Flow cytometry analysis demonstrated that LPS markedly augmented phagocytosis of Candida cells by increasing the number of yeasts ingested per neutrophil as well as the number of neutrophils capable of ingesting fungal cells. LPS activation caused augmented release of lactoferrin, an iron-binding protein which itself could inhibit the growth of C. albicans in vitro. Antibodies against lactoferrin effectively and specifically reduced the anti-C. albicans activity of both LPS-stimulated and unstimulated PMN. Northern (RNA blot) analysis showed enhanced production of mRNAs for interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6 and in neutrophils within 1 h of stimulation with LPS. The cytokines were also detected in the supernatant of the activated PMN, and their synthesis was prevented by pretreatment of LPS-stimulated PMN with protein synthesis inhibitors, such as emetine and cycloheximide. These inhibitors, however, did not block either lactoferrin release or the anti-Candida activity of LPS-stimulated PMN. These results demonstrate the ability of various bacterial LPSs to augment neutrophil function against C. albicans and suggest that the release of a candidastatic, iron-binding protein, lactoferrin, may contribute to the antifungal effect of PMN. Moreover, the ability to produce cytokines upon stimulation by ubiquitous microbial products such as the endotoxins points to an extraphagocytic, immunomodulatory role of PMN during infection.

  15. C. albicans growth, transition, biofilm formation, and gene expression modulation by antimicrobial decapeptide KSL-W

    Science.gov (United States)

    2013-01-01

    Background Antimicrobial peptides have been the focus of much research over the last decade because of their effectiveness and broad-spectrum activity against microbial pathogens. These peptides also participate in inflammation and the innate host defense system by modulating the immune function that promotes immune cell adhesion and migration as well as the respiratory burst, which makes them even more attractive as therapeutic agents. This has led to the synthesis of various antimicrobial peptides, including KSL-W (KKVVFWVKFK-NH2), for potential clinical use. Because this peptide displays antimicrobial activity against bacteria, we sought to determine its antifungal effect on C. albicans. Growth, hyphal form, biofilm formation, and degradation were thus examined along with EFG1, NRG1, EAP1, HWP1, and SAP 2-4-5-6 gene expression by quantitative RT-PCR. Results This study demonstrates that KSL-W markedly reduced C. albicans growth at both early and late incubation times. The significant effect of KSL-W on C. albicans growth was observed beginning at 10 μg/ml after 5 h of contact by reducing C. albicans transition and at 25 μg/ml by completely inhibiting C. albicans transition. Cultured C. albicans under biofilm-inducing conditions revealed that both KSL-W and amphotericin B significantly decreased biofilm formation at 2, 4, and 6 days of culture. KSL-W also disrupted mature C. albicans biofilms. The effect of KSL-W on C. albicans growth, transition, and biofilm formation/disruption may thus occur through gene modulation, as the expression of various genes involved in C. albicans growth, transition and biofilm formation were all downregulated when C. albicans was treated with KSL-W. The effect was greater when C. albicans was cultured under hyphae-inducing conditions. Conclusions These data provide new insight into the efficacy of KSL-W against C. albicans and its potential use as an antifungal therapy. PMID:24195531

  16. Reduced CX3CL1 secretion contributes to the susceptibility of oral leukoplakia-associated fibroblasts to Candida albicans

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    Ran Cheng

    2016-11-01

    Full Text Available Candida leukoplakia (OLK is a kind of oral leukoplakia combined with chronic candidal infection, which plays an important role in the malignant transformation of OLK. However, little is known about the etiology, including susceptibility of leukoplakia to candidal adhesion, invasion and infection. Some antimicrobial peptides secreted by oral epithelial cells or fibroblasts potentially have antifungal activities against Candida albicans (C. albicans. In this study, we established three co-culture models to simulate different C. albicans-fibroblasts interactions during progression of candida leukoplakia. The susceptibility of oral leukoplakia-associated fibroblasts (LKAFs to C. albicans and its underlying mechanism were determined. Samples of 14 LKAFs and 10 normal fibroblasts (NFs were collected. The co-culture models showed that LKAFs had promoted the adhesion, invasion, and survival of C. albicans compared with NFs. CX3CL1, a chemokine with antifungal activity, was less abundant in LKAFs than NFs. Overexpression of CX3CL1 via transfection in LKAFs could partly restore the resistance to C. albicans. We also showed that inhibition of ERK could suppress CX3CL1 secretion. While phosphor-ERK was inhibited in LKAFs compared with NFs. Besides, the expression of a shedding enzyme for CX3CL1, disintegrin and metalloproteinase domain (ADAM 17 was decreased in LKAFs than NFs. In conclusion, LKAFs produced and secreted less CX3CL1 by inhibiting the ERK signaling pathway, thereby contributing to impaired cell resistance to C. albicans.

  17. Characterization of a putative spindle assembly checkpoint kinase Mps1, suggests its involvement in cell division, morphogenesis and oxidative stress tolerance in Candida albicans.

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    Mohan Kamthan

    Full Text Available In Saccharomyces cerevisiae MPS1 is one of the major protein kinase that governs the spindle checkpoint pathway. The S. cerevisiae structural homolog of opportunistic pathogen Candida albicans CaMPS1, is indispensable for the cell viability. The essentiality of Mps1 was confirmed by Homozygote Trisome test. To determine its biological function in this pathogen conditional mutant was generated through regulatable MET3 promoter. Examination of heterozygous and conditional (+Met/Cys mps1 mutants revealed a mitosis specific arrest phenotype, where mutants showed large buds with undivided nuclei. Flowcytometry analysis revealed abnormal ploidy levels in mps1 mutant. In presence of anti-microtubule drug Nocodazole, mps1 mutant showed a dramatic loss of viability suggesting a role of Mps1 in Spindle Assembly Checkpoint (SAC activation. These mutants were also defective in microtubule organization. Moreover, heterozygous mutant showed defective in-vitro yeast to hyphae morphological transition. Growth defect in heterozygous mutant suggest haploinsufficiency of this gene. qRT PCR analysis showed around 3 fold upregulation of MPS1 in presence of serum. This expression of MPS1 is dependent on Efg1 and is independent of other hyphal regulators like Ras1 and Tpk2. Furthermore, mps1 mutants were also sensitive to oxidative stress. Heterozygous mps1 mutant did not undergo morphological transition and showed 5-Fold reduction in colony forming units in response to macrophage. Thus, the vital checkpoint kinase, Mps1 besides cell division also has a role in morphogenesis and oxidative stress tolerance, in this pathogenic fungus.

  18. 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

    Science.gov (United States)

    Ao, Jie; Chinnici, Jennifer L.; Maddi, Abhiram

    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-linked outer chain mannan, is essential for the incorporation of cell wall glycoproteins into the Candida albicans cell wall. Using endoglycosidases, we show that C. albicans cell wall proteins are cross-linked into the cell wall via their N-linked outer chain mannans. We further demonstrate that the Dfg5p and Dcw1p α-1,6-mannanases are needed for the incorporation of cell wall glycoproteins into the C. albicans cell wall. Our results support the hypothesis that the Dfg5p and Dcw1p α-1,6-mannanases incorporate cell wall glycoproteins into the C. albicans cell wall by cross-linking outer chain mannans into the cell wall glucan-chitin matrix. PMID:26048011

  19. A ReaxFF-based molecular dynamics study of the mechanisms of interactions between reactive oxygen plasma species and the Candida albicans cell wall

    Science.gov (United States)

    Zhao, T.; Shi, L.; Zhang, Y. T.; Zou, L.; Zhang, L.

    2017-10-01

    Atmospheric pressure non-equilibrium plasmas have attracted significant attention and have been widely used to inactivate pathogens, yet the mechanisms underlying the interactions between plasma-generated species and bio-organisms have not been elucidated clearly. In this paper, reactive molecular dynamics simulations are employed to investigate the mechanisms of interactions between reactive oxygen plasma species (O, OH, and O2) and β-1,6-glucan (a model for the C. albicans cell wall) from a microscopic point of view. Our simulations show that O and OH species can break structurally important C-C and C-O bonds, while O2 molecules exhibit only weak, non-bonded interactions with β-1,6-glucan. Hydrogen abstraction from hydroxyl or CH groups occurs first in all bond cleavage mechanisms. This is followed by a cascade of bond cleavage and double bond formation events. These lead to the destruction of the fungal cell wall. O and OH have similar effects related to their bond cleavage mechanisms. Our simulation results provide fundamental insights into the mechanisms underlying the interactions between reactive oxygen plasma species and the fungal cell wall of C. albicans at the atomic level.

  20. Symbiotic Plant Peptides Eliminate Candida albicans Both In Vitro and in an Epithelial Infection Model and Inhibit the Proliferation of Immortalized Human Cells

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    Lilla Ördögh

    2014-01-01

    Full Text Available The increasing number of multidrug-resistant microbes now emerging necessitates the identification of novel antimicrobial agents. Plants produce a great variety of antimicrobial peptides including hundreds of small, nodule-specific cysteine-rich NCR peptides that, in the legume Medicago truncatula, govern the differentiation of endosymbiotic nitrogen fixing bacteria and, in vitro, can display potent antibacterial activities. In this study, the potential candidacidal activity of 19 NCR peptides was investigated. Cationic NCR peptides having an isoelectric point above 9 were efficient in killing Candida albicans, one of the most common fungal pathogens of humans. None of the tested NCR peptides were toxic for immortalized human epithelial cells at concentrations that effectively killed the fungus; however, at higher concentrations, some of them inhibited the division of the cells. Furthermore, the cationic peptides successfully inhibited C. albicans induced human epithelial cell death in an in vitro coculture model. These results highlight the therapeutic potential of cationic NCR peptides in the treatment of candidiasis.

  1. Anti-Candida albicans biofilm effect of novel heterocyclic compounds.

    Science.gov (United States)

    Kagan, Sarah; Jabbour, Adel; Sionov, Edward; Alquntar, Abed A; Steinberg, Doron; Srebnik, Morris; Nir-Paz, Ran; Weiss, Aryeh; Polacheck, Itzhack

    2014-02-01

    The aims of this study were to develop new anti-biofilm drugs, examine their activity against Candida albicans biofilm and investigate their structure-activity relationship and mechanism of action. A series of thiazolidinedione and succinimide derivatives were synthesized and their ability to inhibit C. albicans biofilm formation and destroy pre-formed biofilm was tested. The biofilms' structure, metabolic activity and viability were determined by XTT assay and propidium iodide and SYTO 9 live/dead stains combined with confocal microscopic analysis. The effect of the most active compounds on cell morphology, sterol distribution and cell wall morphology and composition was then determined by specific fluorescent stains and transmission electron microscopy. Most of the compounds were active at sub-MICs. Elongation of the aliphatic side chain resulted in reduced anti-biofilm activity and the sulphur atom contributed to biofilm killing, indicating a structure-activity relationship. The compounds differed in their effects on biofilm viability, yeast-to-hyphal form transition, hyphal morphology, cell wall morphology and composition, and sterol distribution. The most effective anti-biofilm compounds were the thiazolidinedione S8H and the succinimide NA8. We developed novel anti-biofilm agents that both inhibited and destroyed C. albicans biofilm. With some further development, these agents might be suitable for therapeutic purposes.

  2. In vitro modification of Candida albicans invasiveness.

    Science.gov (United States)

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

    1986-05-01

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

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

    Science.gov (United States)

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

    1986-03-01

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

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

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    Sandra Gil-Alonso

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

  5. The antagonistic effect of Saccharomyces boulardii on Candida albicans filamentation, adhesion and biofilm formation.

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    Krasowska, Anna; Murzyn, Anna; Dyjankiewicz, Agnieszka; Łukaszewicz, Marcin; Dziadkowiec, Dorota

    2009-12-01

    The dimorphic fungus Candida albicans is a member of the normal flora residing in the intestinal tract of humans. In spite of this, under certain conditions it can induce both superficial and serious systemic diseases, as well as be the cause of gastrointestinal infections. Saccharomyces boulardii is a yeast strain that has been shown to have applications in the prevention and treatment of intestinal infections caused by bacterial pathogens. The purpose of this study was to determine whether S. boulardii affects the virulence factors of C. albicans. We demonstrate the inhibitory effect of live S. boulardii cells on the filamentation (hyphae and pseudohyphae formation) of C. albicans SC5314 strain proportional to the amount of S. boulardii added. An extract from S. boulardii culture has a similar effect. Live S. boulardii and the extract from S. boulardii culture filtrate diminish C. albicans adhesion to and subsequent biofilm formation on polystyrene surfaces under both aerobic and microaerophilic conditions. This effect is very strong and requires lower doses of S. boulardii cells or concentrations of the extract than serum-induced filamentation tests. Saccharomyces boulardii has a strong negative effect on very important virulence factors of C. albicans, i.e. the ability to form filaments and to adhere and form biofilms on plastic surfaces.

  6. The synthesis, regulation, and functions of sterols in Candida albicans: Well-known but still lots to learn.

    Science.gov (United States)

    Lv, Quan-Zhen; Yan, Lan; Jiang, Yuan-Ying

    2016-08-17

    Sterols are the basal components of the membranes of the fungal pathogen Candida albicans, and these membranes determine the susceptibility of C. albicans cells to a variety of stresses, such as ionic, osmotic and oxidative pressures, and treatment with antifungal drugs. The common antifungal azoles in clinical use are targeted to the biosynthesis of ergosterol. In the past years, the synthesis, storage and metabolism of ergosterol in Saccharomyces cerevisiae has been characterized in some detail; however, these processes has not been as well investigated in the human opportunistic pathogen C. albicans. In this review, we summarize the genes involved in ergosterol synthesis and regulation in C. albicans. As well, genes in S. cerevisiae implicated in ergosterol storage and conversions with other lipids are noted, as these provide us clues and directions for the study of the homologous genes in C. albicans. In this report we have particularly focused on the essential roles of ergosterol in the dynamic process of cell biology and its fundamental status in the biological membrane system that includes lipid rafts, lipid droplets, vacuoles and mitochondria. We believe that a thorough understanding of this classic and essential pathway will give us new ideas about drug resistance and morphological switching in C. albicans.

  7. The Candida albicans Biofilm Matrix: Composition, Structure and Function.

    Science.gov (United States)

    Pierce, Christopher G; Vila, Taissa; Romo, Jesus A; Montelongo-Jauregui, Daniel; Wall, Gina; Ramasubramanian, Anand; Lopez-Ribot, Jose L

    2017-03-01

    A majority of infections caused by Candida albicans -the most frequent fungal pathogen-are associated with biofilm formation. A salient feature of C. albicans biofilms is the presence of the biofilm matrix. This matrix is composed of exopolymeric materials secreted by sessile cells within the biofilm, in which all classes of macromolecules are represented, and provides protection against environmental challenges. In this review, we summarize the knowledge accumulated during the last two decades on the composition, structure, and function of the C. albicans biofilm matrix. Knowledge of the matrix components, its structure, and function will help pave the way to novel strategies to combat C. albicans biofilm infections.

  8. Comparison of the adhesion ability of Candida albicans strains to ...

    African Journals Online (AJOL)

    The purpose of the present study is to investigate the ability of oral Candida albicans strains to adhere to Caco-2 and Hep-2 epithelial cells, to produce slime using Congo red and Safranin methods and to form a biofilm on polymethylmethacrylate. A total of 20 C. albicans strains were tested in the present work. The biofilm ...

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

    Science.gov (United States)

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

    2016-12-01

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

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

    Science.gov (United States)

    Rukayadi, Yaya; Hwang, Jae-Kwan

    2013-07-01

    The purpose of this study was to investigate the activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. on Candida albicans biofilms at adherent, intermediate, and mature phase of growth. C. albicans biofilms were formed in flat-bottom 96-well microtiter plates. The biofilms of C. albicans at different phases of development were exposed to xanthorrhizol at different concentrations (0.5 µg/mL-256 µg/mL) for 24 h. The metabolic activity of cells within the biofilms was quantified using the XTT reduction assay. Sessile minimum inhibitory concentrations (SMICs) were determined at 50% and 80% reduction in the biofilm OD₄₉₀ compared to the control wells. The SMIC₅₀ and SMIC₈₀ of xanthorrhizol against 18 C. albicans biofilms were 4--16 µg/mL and 8--32 µg/mL, respectively. The results demonstrated that the activity of xanthorrhizol in reducing C. albicans biofilms OD₄₉₀ was dependent on the concentration and the phase of growth of biofilm. Xanthorrhizol at concentration of 8 µg/mL completely reduced in biofilm referring to XTT-colorimetric readings at adherent phase, whereas 32 µg/mL of xanthorrhizol reduced 87.95% and 67.48 % of biofilm referring to XTT-colorimetric readings at intermediate and mature phases, respectively. Xanthorrhizol displayed potent activity against C. albicans biofilms in vitro and therefore might have potential therapeutic implication for biofilm-associated candidal infections. Copyright © 2012 John Wiley & Sons, Ltd.

  11. Rheumatoid arthritis patients exhibit impaired Candida albicans-specific Th17 responses.

    Science.gov (United States)

    Bishu, Shrinivas; Su, Ee Wern; Wilkerson, Erich R; Reckley, Kelly A; Jones, Donald M; McGeachy, Mandy J; Gaffen, Sarah L; Levesque, Marc C

    2014-02-11

    Accumulating data implicate the CD4+ T cell subset (Th17 cells) in rheumatoid arthritis (RA). IL-17 is an inflammatory cytokine that induces tumor necrosis factor (TNF)α, IL-1β and IL-6, all of which are targets of biologic therapies used to treat RA. RA patients are well documented to experience more infections than age-matched controls, and biologic therapies further increase the risk of infection. The Th17/IL-17 axis is vital for immunity to fungi, especially the commensal fungus Candida albicans. Therefore, we were prompted to examine the relationship between RA and susceptibility to C. albicans because of the increasing interest in Th17 cells and IL-17 in driving autoimmunity, and the advent of new biologics that target this pathway. We analyzed peripheral blood and saliva from 48 RA and 33 healthy control subjects. To assess C. albicans-specific Th17 responses, PBMCs were co-cultured with heat-killed C. albicans extract, and IL-17A levels in conditioned supernatants were measured by ELISA. The frequency of Th17 and Th1 cells was determined by flow cytometry. As a measure of IL-17A-mediated effector responses, we evaluated C. albicans colonization rates in the oral cavity, salivary fungicidal activity and levels of the antimicrobial peptide β-defensin 2 (BD2) in saliva. Compared to controls, PBMCs from RA subjects exhibited elevated baseline production of IL-17A (P = 0.004), although they had similar capacity to produce IL-17A in response to Th17 cell differentiating cytokines (P = 0.91). However RA PBMCs secreted less IL-17A in response to C. albicans antigens (P = 0.006). Significantly more RA patients were colonized with C. albicans in the oral cavity than healthy subjects (P = 0.02). Concomitantly, RA saliva had reduced concentrations of salivary BD2 (P = 0.02). Nonetheless, salivary fungicidal activity was preserved in RA subjects (P = 0.70). RA subjects exhibit detectable impairments in oral immune responses to C. albicans, a

  12. 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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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 2+ –Mg 2+ ATPase in C. albicans. • Baicalin increases the endocytic free Ca 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 3 H-UdR, 3 H-TdR and 3 H-leucine incorporation into C. albicans using the isotope incorporation technology. The activities of Succinate Dehydrogenase (SDH), cytochrome oxidase (CCO) and Ca 2+ –Mg 2+ ATPase, cytosolic Ca 2+ concentration, the cell cycle and apoptosis, as well as the ultrastructure of C.albicans were also tested. We found that baicalin inhibited 3 H-UdR, 3 H-TdR and 3 H-leucine incorporation into C.albicans (P < 0.005). The activities of the SDH and Ca 2+ –Mg 2+ ATPase of C.albicans in baicalin groups were lower than those in control group (P < 0.05). Ca 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 2+ –Mg 2+ ATPase, increasing cytosolic Ca 2+ content and damaging the ultrastructure of C. albicans

  14. 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

  15. Effects of Acetone Fraction From Buchenavia tomentosa Aqueous Extract and Gallic Acid on Candida albicans Biofilms and Virulence Factors

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    Guilherme R. Teodoro

    2018-04-01

    Full Text Available A promising anti-Candida activity of Buchenavia tomentosa extracts was recently described. In the present work, experiments were carried out to determine the fraction with higher antifungal activity from a B. tomentosa extract. Acetone fraction (AF was obtained from the aqueous extract from dried leaves (5 min/100°C and it was the most effective one. Gallic acid (GA was identified by electrospray ionization mass spectrometry (ESI–MS and also chosen to perform antifungal tests due to its promising activity on Candida albicans. Minimal inhibitory and fungicidal concentrations (MIC and MFC were determined by broth microdilution technique. The effect on virulence factors of C. albicans was evaluated, and the cytotoxicity was determined. MIC50 and MIC90 values were both equal to 0.625 mg ml-1 for AF and 2.5 and 5 mg ml-1, respectively, for GA. AF and GA showed ability to inhibit C. albicans adherence and to disrupt 48 h-biofilm. AF and GA were effective in reducing the formation of hyphae of C. albicans SC5314. AF and GA decreased adherence of C. albicans to oral epithelial cells. AF and GA showed slight to moderate toxicity to Vero cells. This result suggests further studies for topic use of these compounds. AF, which contains a combination of several molecules, presented greater potential of antimicrobial activity than GA, with lower values of MIC and lower cytoxicity.

  16. Growth of Candida albicans hyphae.

    Science.gov (United States)

    Sudbery, Peter E

    2011-08-16

    The fungus Candida albicans is often a benign member of the mucosal flora; however, it commonly causes mucosal disease with substantial morbidity and in vulnerable patients it causes life-threatening bloodstream infections. A striking feature of its biology is its ability to grow in yeast, pseudohyphal and hyphal forms. The hyphal form has an important role in causing disease by invading epithelial cells and causing tissue damage. This Review describes our current understanding of the network of signal transduction pathways that monitors environmental cues to activate a programme of hypha-specific gene transcription, and the molecular processes that drive the highly polarized growth of hyphae.

  17. Emerging azole resistance among Candida albicans from clinical ...

    African Journals Online (AJOL)

    Candida albicans is one of the most frequently isolated yeasts in clinical laboratories and accounts for up to 80 % of the yeasts recovered from sites of infection. The study was set out to determine antifungal susceptibility of clinical isolates of Candida albicans and to establish the Minimum Inhibitory Concentrations (MIC) to ...

  18. Difunctional bacteriophage conjugated with photosensitizers for Candida albicans-targeting photodynamic inactivation.

    Science.gov (United States)

    Dong, Shuai; Shi, Hongxi; Zhang, Xintong; Chen, Xi; Cao, Donghui; Mao, Chuanbin; Gao, Xiang; Wang, Li

    2018-01-01

    Candida albicans is the most prevalent fungal pathogen of the human microbiota, causing infections ranging from superficial infections of the skin to life-threatening systemic infections. Due to the increasing occurrence of antibiotic-resistant C. albicans strains, new approaches to control this pathogen are needed. Photodynamic inactivation is an emerging alternative to treat infections based on the interactions between visible light and photosensitisers, in which pheophorbide a (PPA) is a chlorophyll-based photosensitizer that could induce cell death after light irradiation. Due to PPA's phototoxicity and low efficiency, the main challenge is to implement photosensitizer cell targeting and attacking. In this study, PPA was conjugated with JM-phage by EDC/NHS crosslinking. UV-Vis spectra was used to determine the optimum conjugation percentages of PPA and JM-phage complex for photodynamic inactivation. After photodynamic inactivation, the efficacy of PPA-JM-phage was assessed by performing in vitro experiments, such as MTS assay, scanning electron microscopy, measurement of dysfunctional mitochondria, ROS accumulation, S cell arrest and apoptotic pathway. A single-chain variable-fragment phage (JM) with high affinity to MP65 was screened from human single-fold single-chain variable-fragment libraries and designed as a binding target for C. albicans cells. Subsequently, PPa was integrated into JM phage to generate a combined nanoscale material, which was called PPA-JM-phage. After photodynamic inactivation, the growth of C. albicans was inhibited by PPA-JM-phage and apoptosis was observed. Scanning electron microscopy analysis revealed shrinking and rupturing of C. albicans . We also found that depolarization of mitochondrial membrane potential was decreased and intracellular reactive oxygen species levels were elevated significantly in C. albicans inhibited by PPA-JM-phage. Additionally, PPA-JM-phage also lead to S-phase arrest, and metacaspase activation

  19. Difunctional bacteriophage conjugated with photosensitizers for Candida albicans-targeting photodynamic inactivation

    Directory of Open Access Journals (Sweden)

    Dong S

    2018-04-01

    Full Text Available Shuai Dong,1,2 Hongxi Shi,1 Xintong Zhang,1,2 Xi Chen,1 Donghui Cao,2 Chuanbin Mao,3,4 Xiang Gao,1 Li Wang1 1Key Laboratory of Molecular Epigenetics of Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, 2First Hospital of Jilin University, Changchun, Jilin, 3School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China; 4Department of Chemistry and Biochemistry, Stephenson Life Science Research Center, University of Oklahoma, Norman, OK, USA Background: Candida albicans is the most prevalent fungal pathogen of the human microbiota, causing infections ranging from superficial infections of the skin to life-threatening systemic infections. Due to the increasing occurrence of antibiotic-resistant C. albicans strains, new approaches to control this pathogen are needed. Photodynamic inactivation is an emerging alternative to treat infections based on the interactions between visible light and photosensitisers, in which pheophorbide a (PPA is a chlorophyll-based photosensitizer that could induce cell death after light irradiation. Due to PPA’s phototoxicity and low efficiency, the main challenge is to implement photosensitizer cell targeting and attacking. Methods: In this study, PPA was conjugated with JM-phage by EDC/NHS crosslinking. UV-Vis spectra was used to determine the optimum conjugation percentages of PPA and JM-phage complex for photodynamic inactivation. After photodynamic inactivation, the efficacy of PPA-JM-phage was assessed by performing in vitro experiments, such as MTS assay, scanning electron microscopy, measurement of dysfunctional mitochondria, ROS accumulation, S cell arrest and apoptotic pathway.Results: A single-chain variable-fragment phage (JM with high affinity to MP65 was screened from human single-fold single-chain variable-fragment libraries and designed as a binding target for C. albicans cells. Subsequently, PPa was integrated into JM phage to generate

  20. 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.

  1. Detecting Candida albicans in human milk.

    Science.gov (United States)

    Morrill, Jimi Francis; Pappagianis, Demosthenes; Heinig, M Jane; Lönnerdal, Bo; Dewey, Kathryn G

    2003-01-01

    Procedures for diagnosis of mammary candidosis, including laboratory confirmation, are not well defined. Lactoferrin present in human milk can inhibit growth of Candida albicans, thereby limiting the ability to detect yeast infections. The inhibitory effect of various lactoferrin concentrations on the growth of C. albicans in whole human milk was studied. The addition of iron to the milk led to a two- to threefold increase in cell counts when milk contained 3.0 mg of lactoferrin/ml and markedly reduced the likelihood of false-negative culture results. This method may provide the necessary objective support needed for diagnosis of mammary candidosis.

  2. Candida albicans escapes from mouse neutrophils

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...

  3. The determination of optimal cells disintegration method of Candida albicans and Candida tropicalis fungals

    OpenAIRE

    M. V. Rybalkyn

    2014-01-01

    Candidiasis is common infectious disease that affects the mucous membranes, skin, nails, hair, and internal organs. Now Ukraine has neither domestic nor registered imported vaccine against candidiasis. The development of vaccine for prevention and treatment of candidiasis is a key issue in modern medicine and pharmacy. Similar research is actively conducted in many countries of the world: Russia, USA, Japan and others. It should be noted that researchers have not yet reached a consensus view ...

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

    Science.gov (United States)

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

    2015-09-01

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

  5. Undecylenic Acid Inhibits Morphogenesis of Candida albicans

    OpenAIRE

    McLain, Nealoo; Ascanio, Rhoda; Baker, Carol; Strohaver, Robert A.; Dolan, Joseph W.

    2000-01-01

    Resilient liners are frequently used to treat denture stomatitis, a condition often associated with Candida albicans infections. Of 10 liners tested, 2 were found to inhibit the switch from the yeast form to hyphae and a third was found to stimulate this switch. The inhibitor was determined to be undecylenic acid.

  6. Undecylenic acid inhibits morphogenesis of Candida albicans.

    Science.gov (United States)

    McLain, N; Ascanio, R; Baker, C; Strohaver, R A; Dolan, J W

    2000-10-01

    Resilient liners are frequently used to treat denture stomatitis, a condition often associated with Candida albicans infections. Of 10 liners tested, 2 were found to inhibit the switch from the yeast form to hyphae and a third was found to stimulate this switch. The inhibitor was determined to be undecylenic acid.

  7. 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.

  8. 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.

  9. The Candida albicans stress response gene Stomatin-Like Protein 3 is implicated in ROS-induced apoptotic-like death of yeast phase cells.

    Directory of Open Access Journals (Sweden)

    Karen A Conrad

    Full Text Available The ubiquitous presence of SPFH (Stomatin, Prohibitin, Flotillin, HflK/HflC proteins in all domains of life suggests that their function would be conserved. However, SPFH functions are diverse with organism-specific attributes. SPFH proteins play critical roles in physiological processes such as mechanosensation and respiration. Here, we characterize the stomatin ORF19.7296/SLP3 in the opportunistic human pathogen Candida albicans. Consistent with the localization of stomatin proteins, a Slp3p-Yfp fusion protein formed visible puncta along the plasma membrane. We also visualized Slp3p within the vacuolar lumen. Slp3p primary sequence analyses identified four putative S-palmitoylation sites, which may facilitate membrane localization and are conserved features of stomatins. Plasma membrane insertion sequences are present in mammalian and nematode SPFH proteins, but are absent in Slp3p. Strikingly, Slp3p was present in yeast cells, but was absent in hyphal cells, thus categorizing it as a yeast-phase specific protein. Slp3p membrane fluorescence significantly increased in response to cellular stress caused by plasma membrane, cell wall, oxidative, or osmotic perturbants, implicating SLP3 as a general stress-response gene. A slp3Δ/Δ homozygous null mutant had no detected phenotype when slp3Δ/Δ mutants were grown in the presence of a variety of stress agents. Also, we did not observe a defect in ion accumulation, filamentation, endocytosis, vacuolar structure and function, cell wall structure, or cytoskeletal structure. However, SLP3 over-expression triggered apoptotic-like death following prolonged exposure to oxidative stress or when cells were induced to form hyphae. Our findings reveal the cellular localization of Slp3p, and for the first time associate Slp3p function with the oxidative stress response.

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

    Directory of Open Access Journals (Sweden)

    Anand Srinivasan

    2011-04-01

    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.

  11. 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

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

    Science.gov (United States)

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

    2016-09-01

    Three chalcones, 2'-hydroxy-4,4',6'-trimethoxychalcone, 2'-hydroxy-4,4',6'-tetramethoxychalcone, and 3,2'-dihydroxy-4,4',6'-trimethoxychalcone, were isolated from the leaves of Piper hispidum in a bioguided fractionation of crude extract. The antimicrobial activity of crude extract of P. hispidum leaves was determined against bacteria Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus and yeasts Candida albicans, C. parapsilosis and C. tropicalis. Fractions and chalcones were tested against C. albicans and S. aureus. The checkerboard assay was performed to assess synergic interactions between extract and antifungal drugs, and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction assay was used to evaluate anti-biofilm effects of extract. The extract was active against yeasts, S. aureus and B. subtilis with MIC values between 15.6 and 62.5μg/mL. Synergistic effects of extract associated with fluconazole and nystatin were observed against C. albicans, with fractional inhibitory concentration indices of 0.37 and 0.24, respectively. The extract was also effective against C. albicans and S. aureus biofilm cells at concentrations of 62.5 and 200μg/mL, respectively. Thus, P. hispidum may be a possible source of bioactive substances with antimicrobial properties. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Antibiofilm and Antihyphal Activities of Cedar Leaf Essential Oil, Camphor, and Fenchone Derivatives against Candida albicans

    OpenAIRE

    Manoharan, Ranjith Kumar; Lee, Jin-Hyung; Lee, Jintae

    2017-01-01

    Candida albicans can form biofilms composed of yeast, hyphal, and pseudohyphal elements, and C. albicans cells in the hyphal stage could be a virulence factor. The present study describes the chemical composition, antibiofilm, and antihyphal activities of cedar leaf essential oil (CLEO), which was found to possess remarkable antibiofilm activity against C. albicans but not to affect its planktonic cell growth. Nineteen components were identified in CLEO by gas chromatography/mass spectrometry...

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

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    Read Pukkila-Worley

    2011-06-01

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

  15. Antifungal Activity of Aqueous Extracts from Ferula Assa foetida Aerial parts on Candida Albicans and its Comparison with Fluconazole in vitro

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    AA Jafari

    2014-09-01

    Results:Concentrations of 8.75 mg/ml aerial parts of Ferula assafoetida completely inhibited the growth of Candida albicans and killed all viable cells (MFC. Concentrations of 0.273 and 4.4 mg/ml Ferula aqueous extracts were also determined as MIC50 and MIC90. In case of Fluconazole, 128 µg/ml concentrationis determined as MFC and 0.5 µg/ml concentration is also known as MIC50. Conclusion:Results of the current study showed that the aqueous extract of Ferula assafoetida aerial parts has inhibitory and candidacidal effect against Candida albicans and further in vivo studies are suggested.

  16. Polyethylene glycol-functionalized poly (Lactic Acid-co-Glycolic Acid and graphene oxide nanoparticles induce pro-inflammatory and apoptotic responses in Candida albicans-infected vaginal epithelial cells.

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    R Doug Wagner

    Full Text Available Mucous-penetrating nanoparticles consisting of poly lactic acid-co-glycolic acid (PLGA-polyethylene glycol (PEG could improve targeting of microbicidal drugs for sexually transmitted diseases by intravaginal inoculation. Nanoparticles can induce inflammatory responses, which may exacerbate the inflammation that occurs in the vaginal tracts of women with yeast infections. This study evaluated the effects of these drug-delivery nanoparticles on VK2(E6/E7 vaginal epithelial cell proinflammatory responses to Candida albicans yeast infections. Vaginal epithelial cell monolayers were infected with C. albicans and exposed to 100 μg/ml 49.5 nm PLGA-PEG nanospheres or 20 μg/ml 1.1 x 500 nm PEG-functionalized graphene oxide (GO-PEG sheets. The cells were assessed for changes in mRNA and protein expression of inflammation-related genes by RT-qPCR and physiological markers of cell stress using high content analysis and flow cytometry. C. albicans exposure suppressed apoptotic gene expression, but induced oxidative stress in the cells. The nanomaterials induced cytotoxicity and programmed cell death responses alone and with C. albicans. PLGA-PEG nanoparticles induced mRNA expression of apoptosis-related genes and induced poly (ADP-ribose polymerase (PARP cleavage, increased BAX/BCL2 ratios, and chromatin condensation indicative of apoptosis. They also induced autophagy, endoplasmic reticulum stress, and DNA damage. They caused the cells to excrete inflammatory recruitment molecules chemokine (C-X-C motif ligand 1 (CXCL1, interleukin-1α (IL1A, interleukin-1β (IL1B, calprotectin (S100A8, and tumor necrosis factor α (TNF. GO-PEG nanoparticles induced expression of necrosis-related genes and cytotoxicity. They reduced autophagy and endoplasmic reticulum stress, and apoptotic gene expression responses. The results show that stealth nanoparticle drug-delivery vehicles may cause intracellular damage to vaginal epithelial cells by several mechanisms and that

  17. Antifungal Activity of Commercial Essential Oils and Biocides against Candida Albicans.

    Science.gov (United States)

    Serra, Elisa; Hidalgo-Bastida, Lilia Araida; Verran, Joanna; Williams, David; Malic, Sladjana

    2018-01-25

    Management of oral candidosis, most frequently caused by Candida albicans , is limited due to the relatively low number of antifungal drugs and the emergence of antifungal tolerance. In this study, the antifungal activity of a range of commercial essential oils, two terpenes, chlorhexidine and triclosan was evaluated against C. albicans in planktonic and biofilm form. In addition, cytotoxicity of the most promising compounds was assessed using murine fibroblasts and expressed as half maximal inhibitory concentrations (IC50). Antifungal activity was determined using a broth microdilution assay. The minimum inhibitory concentration (MIC) was established against planktonic cells cultured in a range of concentrations of the test agents. The minimal biofilm eradication concentration (MBEC) was determined by measuring re-growth of cells after pre-formed biofilm was treated for 24 h with the test agents. All tested commercial essential oils demonstrated anticandidal activity (MICs from 0.06% ( v / v ) to 0.4% ( v / v )) against planktonic cultures, with a noticeable increase in resistance exhibited by biofilms (MBECs > 1.5% ( v / v )). The IC50s of the commercial essential oils were lower than the MICs, while a one hour application of chlorhexidine was not cytotoxic at concentrations lower than the MIC. In conclusion, the tested commercial essential oils exhibit potential as therapeutic agents against C. albicans , although host cell cytotoxicity is a consideration when developing these new treatments.

  18. Evaluation of Antifungal Activity and Mechanism of Action of Citral against Candida albicans

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    Maria Clerya Alvino Leite

    2014-01-01

    Full Text Available Candida albicans is a yeast that commensally inhabits the human body and can cause opportunistic or pathogenic infections. Objective. To investigate the antifungal activity of citral against C. albicans. Methodology. The minimum inhibitory concentration (MIC and the minimum fungicidal concentration (MFC were determined by the broth microdilution techniques. We also investigated possible citral action on cell walls (0.8 M sorbitol, cell membranes (citral to ergosterol binding, the time-kill curve, and biological activity on the yeast’s morphology. Results. The MIC and MFC of citral were, respectively, 64 µg/mL and 256 µg/mL. Involvement with the cell wall and ergosterol binding were excluded as possible mechanisms of action. In the morphological interference assay, it was observed that the product inhibited pseudohyphae and chlamydoconidia formation. The MIC and the MFC of citral required only 4 hours of exposure to effectively kill 99.9% of the inoculum. Conclusion. Citral showed in vitro antifungal potential against strains of C. albicans. Citral’s mechanism of action does not involve the cell wall or ergosterol, and further study is needed to completely describe its effects before being used in the future as a component of new antifungals.

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

    Science.gov (United States)

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

    1984-10-30

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

  20. Whole Saliva has a Dual Role on the Adherence of Candida albicans to Polymethylmetacrylate

    OpenAIRE

    Elguezabal, N; Maza, J.L.; Dorronsoro, S.; Pont?n, J.

    2008-01-01

    Adhesion of Candida albicans to acrylic of dental prostheses or to salivary macromolecules adsorbed on their surface is believed to be a critical event in the development of denture stomatitis. In previous studies our group has shown that adhesion of C. albicans germ tubes to polystyrene is decreased by saliva whereas C. albicans yeast cells adhesion to the same material is enhanced. The results presented in this study confirm this dual role played by whole saliva, since it decreased the adhe...

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

    Science.gov (United States)

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

    2016-03-01

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

  2. Isolation of a variant of Candida albicans.

    Science.gov (United States)

    Buckley, H R; Price, M R; Daneo-Moore, L

    1982-01-01

    During the course of Candida albicans antigen production, a variant of this organism was encountered which did not produce hyphae at 37 degrees C. Presented here are some of the characteristics of this variant. It produces hyphae at 25 degrees C on cornmeal agar and synthetic medium plus N-acetylglucosamine and Tween 80. At 37 degrees C, it does not produce hyphae on these media, although C. albicans normally does produce hyphae under these circumstances. In liquid synthetic medium, this variant does not produce hyphae at 37 degrees C. The variant strain was analyzed for DNA, RNA, protein content, and particle size. After 50 to 70 h in balanced exponential-phase growth, particle size distribution was narrow, and there were no differences in the DNA, RNA, or protein content per particle in the two strains. When balanced exponential-phase cultures were brought into stationary phase, both strains contained the same amount of DNA per cell. Images PMID:6752021

  3. Isolation of a variant of Candida albicans.

    Science.gov (United States)

    Buckley, H R; Price, M R; Daneo-Moore, L

    1982-09-01

    During the course of Candida albicans antigen production, a variant of this organism was encountered which did not produce hyphae at 37 degrees C. Presented here are some of the characteristics of this variant. It produces hyphae at 25 degrees C on cornmeal agar and synthetic medium plus N-acetylglucosamine and Tween 80. At 37 degrees C, it does not produce hyphae on these media, although C. albicans normally does produce hyphae under these circumstances. In liquid synthetic medium, this variant does not produce hyphae at 37 degrees C. The variant strain was analyzed for DNA, RNA, protein content, and particle size. After 50 to 70 h in balanced exponential-phase growth, particle size distribution was narrow, and there were no differences in the DNA, RNA, or protein content per particle in the two strains. When balanced exponential-phase cultures were brought into stationary phase, both strains contained the same amount of DNA per cell.

  4. Development of DNA probes for Candida albicans

    International Nuclear Information System (INIS)

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

    1988-01-01

    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 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. 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.

  6. Cell Elasticity Determines Macrophage Function

    Science.gov (United States)

    Patel, Naimish R.; Bole, Medhavi; Chen, Cheng; Hardin, Charles C.; Kho, Alvin T.; Mih, Justin; Deng, Linhong; Butler, James; Tschumperlin, Daniel; Fredberg, Jeffrey J.; Krishnan, Ramaswamy; Koziel, Henry

    2012-01-01

    Macrophages serve to maintain organ homeostasis in response to challenges from injury, inflammation, malignancy, particulate exposure, or infection. Until now, receptor ligation has been understood as being the central mechanism that regulates macrophage function. Using macrophages of different origins and species, we report that macrophage elasticity is a major determinant of innate macrophage function. Macrophage elasticity is modulated not only by classical biologic activators such as LPS and IFN-γ, but to an equal extent by substrate rigidity and substrate stretch. Macrophage elasticity is dependent upon actin polymerization and small rhoGTPase activation, but functional effects of elasticity are not predicted by examination of gene expression profiles alone. Taken together, these data demonstrate an unanticipated role for cell elasticity as a common pathway by which mechanical and biologic factors determine macrophage function. PMID:23028423

  7. Cell elasticity determines macrophage function.

    Directory of Open Access Journals (Sweden)

    Naimish R Patel

    Full Text Available Macrophages serve to maintain organ homeostasis in response to challenges from injury, inflammation, malignancy, particulate exposure, or infection. Until now, receptor ligation has been understood as being the central mechanism that regulates macrophage function. Using macrophages of different origins and species, we report that macrophage elasticity is a major determinant of innate macrophage function. Macrophage elasticity is modulated not only by classical biologic activators such as LPS and IFN-γ, but to an equal extent by substrate rigidity and substrate stretch. Macrophage elasticity is dependent upon actin polymerization and small rhoGTPase activation, but functional effects of elasticity are not predicted by examination of gene expression profiles alone. Taken together, these data demonstrate an unanticipated role for cell elasticity as a common pathway by which mechanical and biologic factors determine macrophage function.

  8. Candida albicans survival and biofilm formation under starvation conditions.

    Science.gov (United States)

    Ning, Y; Hu, X; Ling, J; Du, Y; Liu, J; Liu, H; Peng, Z

    2013-01-01

    To investigate the survival and biofilm formation capacity of Candida albicans in starvation and under anaerobic conditions. Candida albicans growth and survival were monitored in vitro for up to 8 months. Fungal suspensions from late exponential, stationary and starvation phases were incubated on human dentine, polystyrene and glass slides. Scanning electron microscopy (SEM) was used to observe the process of biofilm formation. 2,3-bis(2-Methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxyanilide inner salt (XTT) reduction assay was performed to quantify the biofilm formation capability, and confocal laser scanning microscopy (CLSM) was used to study and make semi-quantitative comparisons of the ultrastructure of biofilms formed on human dentine. 'XTT bioactivity' and 'COMSTAT results' were analysed by two-way analysis of variance (ANOVA) and one-way ANOVA, respectively. Candida albicans survived for over six months. SEM demonstrated that starving C. albicans produced mature biofilms on different substrata. C. albicans of the same growth phase incubated on human dentine displayed significantly higher biofilm formation capability than on polystyrene or glass slides (P roughness coefficient and surface/volume ratio (P < 0.05). Candida albicans cells can survive and form biofilms in anaerobic and nutrient-limited conditions and may pose a treatment challenge. © 2012 International Endodontic Journal.

  9. 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.

  10. 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

    2016-07-03

    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.

  11. Frequency of Candida albicans in Patients with Funguria.

    Science.gov (United States)

    Jamil, Sana; Jamil, Naz; Saad, Uzma; Hafiz, Saleem; Siddiqui, Sualleha

    2016-02-01

    To determine the frequency of Candida albicansin patients with funguria. Descriptive cross-sectional study. Department of Microbiology, Sindh Institute of Urology and Transplantation, from July to December 2012. Patients’ urine samples with fungus/Candida were included. Candida albicans was identified by the production of tubular structures (germ tubes) on microscopy as per standard procedure followed by inoculation on Chrom agar (Oxoid) and Corn Meal-Tween 80 agar (Oxoid). The identification of other non-albicans Candidaspecies was also done both microscopically and macroscopically as per standard procedure. Out of the 289 isolates, 204 (70.6%) were male patients and 85 (29.4%) were female patients, with 165 (57.1%) from the out-patients and 124 (42.9%) from the in-patients. Five species of Candidawere found to be prevalent including 87 (30.1%) Candida albicans, 176 (60.9%) Candida tropicalis, 14 (4.8%) Candida parapsilosis, 8 (2.8%) Candida glabrata and 4 (1.4%) Candida lusitaniae. Majority of patients with funguria were aged above 50 years (60.2%). In the present study, 30.1% patients with funguria had Candida albicans. The most frequently isolated species was Candida tropicalis(60.9%), followed by other non-albicansCandida. This study has shown the emergence of non-albicans Candidaas a major cause of candiduria.

  12. 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.

  13. Effect of salivary secretory IgA on the adhesion of Candida albicans to polystyrene.

    Science.gov (United States)

    San Millán, R; Elguezabal, N; Regúlez, P; Moragues, M D; Quindós, G; Pontón, J

    2000-09-01

    Attachment of Candida albicans to plastic materials of dental prostheses or to salivary macromolecules adsorbed on their surface is believed to be a critical event in the development of denture stomatitis. In an earlier study, it was shown that adhesion of C. albicans to polystyrene, a model system to study the adhesion of C. albicans to plastic materials, can be partially inhibited with an mAb directed against cell wall polysaccharides of C. albicans. In the present study, the role of whole saliva in the adhesion of C. albicans to polystyrene has been investigated, and three mAbs directed against epitopes of cell wall mannoproteins have been used to mimic the inhibitory effect observed with salivary secretory IgA (sIgA) on the adhesion of C. albicans to polystyrene. In the absence of whole saliva, adherence of C. albicans 3153 increased with germination. However, the presence of whole saliva enhanced the adhesion to polystyrene of C. albicans 3153 yeast cells but decreased the adhesion of germinated cells. The enhancement of adhesion of yeast cells to polystyrene mediated by saliva was confirmed with an agerminative mutant of C. albicans 3153. The inhibition of the adhesion of C. albicans 3153 germ tubes to polystyrene was due to the salivary sIgA since sIgA-depleted saliva enhanced the adhesion of C. albicans 3153 to polystyrene. The inhibitory effect mediated by sIgA was not related to the inhibition of germination but to the blockage of adhesins expressed on the cell wall surface of the germ tubes. The three mAbs studied reduced the adhesion of C. albicans 3153 to polystyrene at levels equivalent to those for purified sIgA. The highest reduction in the adhesion was obtained with the IgA mAb N3B. The best results were obtained when the three mAbs were combined. The results suggest that whole saliva plays a different role in the adhesion of C. albicans to polystyrene depending on the morphological phase of C. albicans. These results may give new insights into the

  14. 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.

  15. Evaluation of Energy Dose and Output Power Optimum of Diode’s Laser of 450 nm and 650 nm in Photoantimicrobial Mechanisms Against Inhibition of C. Albicans Biofilm Cells

    Science.gov (United States)

    Dewi-Astuty, S.; Suhariningsih; Dyah-Astuti, S.; Baktir, A.

    2018-03-01

    Photoantimicrobial as a pathogenic microbial inhibitory therapy system such as C. albicans in biofilms forms has been studied in vitro. Mechanisms of inhibiting called inactivating used the absorb principles of a dye agents such as chlorophyll against the photon energy of diode laser which any number of ROS product depend on energy doses of a laser, time of irradiation, concentration and time of incubation the dyes agent. The inactivation profile of C. albicans biofilm cells was observed based on cell viability reduction after photoantimicrobial treatment with or without oxygenation by XTT assay test. Results show that the inhibiting significantly with the time incubation of the dye agents and the oxygen degree inside the sample. The inhibition for oxygenation biofilm’s group 10% lower than without oxygenation biofilm’s group at the maximum of reduction of cell viability occurred in the 3hour incubation group. Optimum of inactivation are 89.6% (without oxygenation) and 94.8% (with oxygenation) after irradiation with 450 nm laser (power output 128.73 at energy dose 86.09 J/cm2), While, by 650 nm laser (power output 164.53 mW at energy dose 92.52 J/cm2) irradiation treatment obtained optimum of inactivation are 89.5% (without oxygenation) and 92.3% (with oxygenation).

  16. Structural study of phosphomannan of yeast-form cells of Candida albicans J-1012 strain with special reference to application of mild acetolysis.

    Science.gov (United States)

    Kobayashi, H; Shibata, N; Mitobe, H; Ohkubo, Y; Suzuki, S

    1989-08-01

    Structural analysis of the phosphomannan isolated from yeast-form cells of a pathogenic yeast, Candida albicans J-1012 strain, was conducted. Treatment of this phosphomannan (Fr. J) with 10 mM HCl at 100 degrees C for 60 min gave a mixture of beta-1,2-linked manno-oligosaccharides, from tetraose to biose plus mannose, and an acid-stable mannan moiety (Fr. J-a), which was then acetolyzed by means of an acetolysis medium, 100:100:1 (v/v) mixture of (CH3CO)2O, CH3COOH, and H2SO4, at 40 degrees C for 36 h in order to avoid cleavage of the beta-1,2 linkage. The resultant manno-oligosaccharide mixture was fractionated on a column of Bio-Gel P-2 to yield insufficiently resolved manno-oligosaccharide fractions higher than pentaose and lower manno-oligosaccharides ranging from tetraose to biose plus mannose. The higher manno-oligosaccharide fraction was then digested with the Arthrobacter GJM-1 alpha-mannosidase in order to cleave the enzyme-susceptible alpha-1,2 and alpha-1,3 linkages, leaving manno-oligosaccharides containing the beta-1,2 linkage at their nonreducing terminal sites, Manp beta 1----2Manp alpha 1----2Manp alpha 1----2Manp alpha 1----2Man, Manp beta 1----2Manp beta 1----2Manp alpha 1----2Manp alpha 1---- 2Manp alpha 1----2Man, and Manp beta 1----2Manp beta 1----2Manp beta 1----2Manp alpha 1---- 2Manp alpha 1----2Manp alpha 1----2Man. However, the result of acetolysis of Fr. J-a by means of a 10:10:1 (v/v) mixture of (CH3CO)2O, CH3COOH, and H2SO4 at 40 degrees C for 13 h was significantly different from that obtained by the mild acetolysis method; i.e., the amount of mannose was apparently larger than that formed by the mild acetolysis method. In summary, a chemical structure for Fr. J as a highly branched mannan containing 14 different branching moieties was proposed.

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

    Science.gov (United States)

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

    2015-01-01

    In this study, we evaluated the interactions between Candida albicans, Candida krusei and Candida glabrata in mixed infections. Initially, these interactions were studied in biofilms formed in vitro. CFU/mL values of C. albicans were lower in mixed biofilms when compared to the single biofilms, verifying 77% and 89% of C. albicans reduction when this species was associated with C. glabrata and C. krusei, respectively. After that, we expanded this study for in vivo host models of experimental candidiasis. G. mellonella larvae were inoculated with monotypic and heterotypic Candida suspensions for analysis of survival rate and quantification of fungal cells in the haemolymph. In the groups with single infections, 100% of the larvae died within 18 h after infection with C. albicans. However, interaction groups achieved 100% mortality after 72 h of infection by C. albicans-C. glabrata and 96 h of infection by C. albicans-C. krusei. C. albicans CFU/mL values from larvae hemolymph were lower in the interacting groups compared with the monoespecies group after 12 h of infection. In addition, immunosuppressed mice were also inoculated with monotypic and heterotypic microbial suspensions to induce oral candidiasis. C. albicans CFU/mL values recovered from oral cavity of mice were higher in the group with single infection by C. albicans than the groups with mixed infections by C. albicans-C. glabrata and C. albicans-C. krusei. Moreover, the group with single infection by C. albicans had a higher degree of hyphae and epithelial changes in the tongue dorsum than the groups with mixed infections. We concluded that single infections by C. albicans were more harmful for animal models than mixed infections with non-albicans species, suggesting that C. albicans establish competitive interactions with C. krusei and C. glabrata during biofilm formation and development of experimental candidiasis. PMID:26146832

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

    Science.gov (United States)

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

    2015-01-01

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

  19. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Evaluation of adhesion forces of Staphylococcus aureus along the length of Candida albicans hyphae

    NARCIS (Netherlands)

    Ovchinnikova, E.S.; Krom, B.P.; Busscher, H.J.; van der Mei, H.C.

    2012-01-01

    Background Candida albicans is a human fungal pathogen, able to cause both superficial and serious, systemic diseases and is able to switch from yeast cells to long, tube-like hyphae, depending on the prevailing environmental conditions. Both morphological forms of C. albicans are found in infected

  1. Evaluation of adhesion forces of Staphylococcus aureus along the length of Candida albicans hyphae

    NARCIS (Netherlands)

    Ovchinnikova, Ekaterina S.; Krom, Bastiaan P.; Busscher, Henk J.; van der Mei, Henny C.

    2012-01-01

    Background: Candida albicans is a human fungal pathogen, able to cause both superficial and serious, systemic diseases and is able to switch from yeast cells to long, tube-like hyphae, depending on the prevailing environmental conditions. Both morphological forms of C. albicans are found in infected

  2. Plasticity of Candida albicans Biofilms

    Science.gov (United States)

    Daniels, Karla J.

    2016-01-01

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

  3. Effect of essential oils prepared from Thai culinary herbs on sessile Candida albicans cultures.

    Science.gov (United States)

    Hovijitra, Ray S; Choonharuangdej, Suwan; Srithavaj, Theerathavaj

    2016-01-01

    Although medicinal herbs with fungicidal effects have been ubiquitously employed in traditional medicine, such effects of culinary herbs and spices still have to be elucidated. Therefore, it is noteworthy to determine the antifungal efficacy of some edible herbs used in Thai cuisine against sessile Candida albicans cultures, and to inquire if they can be further utilized as naturally-derived antifungals. Fourteen essential oils extracted from Thai culinary herbs and spices were tested for their antifungal activity against C. albicans using the agar disk diffusion method followed by broth micro-dilution method for the determination of minimum inhibitory concentration (MIC) and minimum fungicidal concentration. The oils with potent antifungal effects against planktonic fungi were then assessed for their effect against sessile fungus (adherent organisms and established biofilm culture). MIC of the oils against sessile C. albicans was evaluated by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide reduction assay. All selected culinary herbs and spices, except galangal, garlic, and turmeric, exhibited inhibitory effects on planktonic yeast cells. Cinnamon bark and sweet basil leaf essential oils exhibited potent fungicidal effect on planktonic and sessile fungus. Sessile MICs were 8-16 times higher than planktonic MICs. Consequently, both cinnamon bark and sweet basil leaf herbal oils seem to be highly effective anti-Candida choices. (J Oral Sci 58, 365-371, 2016).

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

    International Nuclear Information System (INIS)

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

    1986-01-01

    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

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

    Science.gov (United States)

    da Silva Dantas, Alessandra; Day, Alison; Ikeh, Mélanie; Kos, Iaroslava; Achan, Beatrice; Quinn, Janet

    2015-01-01

    Candida albicans is a major fungal pathogen of humans, causing approximately 400,000 life-threatening systemic infections world-wide each year in severely immunocompromised patients. An important fungicidal mechanism employed by innate immune cells involves the generation of toxic reactive oxygen species (ROS), such as superoxide and hydrogen peroxide. Consequently, there is much interest in the strategies employed by C. albicans to evade the oxidative killing by macrophages and neutrophils. Our understanding of how C. albicans senses and responds to ROS has significantly increased in recent years. Key findings include the observations that hydrogen peroxide triggers the filamentation of this polymorphic fungus and that a superoxide dismutase enzyme with a novel mode of action is expressed at the cell surface of C. albicans. Furthermore, recent studies have indicated that combinations of the chemical stresses generated by phagocytes can actively prevent C. albicans oxidative stress responses through a mechanism termed the stress pathway interference. In this review, we present an up-date of our current understanding of the role and regulation of oxidative stress responses in this important human fungal pathogen. PMID:25723552

  6. The Hyr1 protein from the fungus Candida albicans is a cross kingdom immunotherapeutic target for Acinetobacter bacterial infection.

    Directory of Open Access Journals (Sweden)

    Priya Uppuluri

    2018-05-01

    Full Text Available Different pathogens share similar medical settings and rely on similar virulence strategies to cause infections. We have previously applied 3-D computational modeling and bioinformatics to discover novel antigens that target more than one human pathogen. Active and passive immunization with the recombinant N-terminus of Candida albicans Hyr1 (rHyr1p-N protect mice against lethal candidemia. Here we determine that Hyr1p shares homology with cell surface proteins of the multidrug resistant Gram negative bacterium, Acinetobacter baumannii including hemagglutinin (FhaB and outer membrane protein A (OmpA. The A. baumannii OmpA binds to C. albicans Hyr1p, leading to a mixed species biofilm. Deletion of HYR1, or blocking of Hyr1p using polyclonal antibodies, significantly reduce A. baumannii binding to C. albicans hyphae. Furthermore, active vaccination with rHyr1p-N or passive immunization with polyclonal antibodies raised against specific peptide motifs of rHyr1p-N markedly improve survival of diabetic or neutropenic mice infected with A. baumannii bacteremia or pneumonia. Antibody raised against one particular peptide of the rHyr1p-N sequence (peptide 5 confers majority of the protection through blocking A. baumannii invasion of host cells and inducing death of the bacterium by a putative iron starvation mechanism. Anti-Hyr1 peptide 5 antibodies also mitigate A. baumannii /C. albicans mixed biofilm formation in vitro. Consistent with our bioinformatic analysis and structural modeling of Hyr1p, anti-Hyr1p peptide 5 antibodies bound to A. baumannii FhaB, OmpA, and an outer membrane siderophore binding protein. Our studies highlight the concept of cross-kingdom vaccine protection against high priority human pathogens such as A. baumannii and C. albicans that share similar ecological niches in immunocompromised patients.

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

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    Fikadu G Tafesse

    2015-10-01

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

  8. Whole Saliva has a Dual Role on the Adherence of Candida albicans to Polymethylmetacrylate.

    Science.gov (United States)

    Elguezabal, N; Maza, J L; Dorronsoro, S; Pontón, J

    2008-01-01

    Adhesion of Candida albicans to acrylic of dental prostheses or to salivary macromolecules adsorbed on their surface is believed to be a critical event in the development of denture stomatitis. In previous studies our group has shown that adhesion of C. albicans germ tubes to polystyrene is decreased by saliva whereas C. albicans yeast cells adhesion to the same material is enhanced. The results presented in this study confirm this dual role played by whole saliva, since it decreased the adhesion of germ tubes but increased the adhesion of yeast cells to polymethylmetacrylate (PMMA). These effects mediated by whole saliva do not seem to be related to an inhibition of the germination of C. albicans, since similar levels of filamentation were observed in presence and absence of saliva. These results may give new insights into the conflicting role of saliva in the adhesion of C. albicans to acrylic resins of dental prostheses.

  9. Frequency of Candida albicans in Patients with Funguria

    International Nuclear Information System (INIS)

    Jamil, S.; Jamil, N.; Hafiz, S.; Siddiqui, S.; Saad, U.

    2016-01-01

    Objective: To determine the frequency of Candida albicans in patients with funguria. Study Design: Descriptive cross-sectional study. Place and Duration of Study: Department of Microbiology, Sindh Institute of Urology and Transplantation, from July to December 2012. Methodology: Patients urine samples with fungus/Candida were included. Candida albicans was identified by the production of tubular structures (germ tubes) on microscopy as per standard procedure followed by inoculation on Chrom agar (Oxoid) and Corn Meal-Tween 80 agar (Oxoid). The identification of other non-albicans Candida species was also done both microscopically and macroscopically as per standard procedure. Results: Out of the 289 isolates, 204 (70.6 percentage) were male patients and 85 (29.4 percentage) were female patients, with 165 (57.1 percentage) from the out-patients and 124 (42.9 percentage) from the in-patients. Five species of Candida were found to be prevalent including 87 (30.1 percentage) Candida albicans, 176 (60.9 percentage) Candida tropicalis, 14 (4.8 percentage) Candida parapsilosis, 8 (2.8 percentage) Candida glabrata and 4 (1.4 percentage) Candida lusitaniae. Majority of patients with funguria were aged above 50 years (60.2 percentage). Conclusion: In the present study, 30.1 percentage patients with funguria had Candida albicans. The most frequently isolated species was Candida tropicalis (60.9 percentage), followed by other non-albicans Candida. This study has shown the emergence of non-albicans Candida as a major cause of candiduria. (author)

  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. Ferric reductase genes involved in high-affinity iron uptake are differentially regulated in yeast and hyphae of Candida albicans.

    Science.gov (United States)

    Jeeves, Rose E; Mason, Robert P; Woodacre, Alexandra; Cashmore, Annette M

    2011-09-01

    The pathogenic yeast Candida albicans possesses a reductive iron uptake system which is active in iron-restricted conditions. The sequestration of iron by this mechanism initially requires the reduction of free iron to the soluble ferrous form, which is catalysed by ferric reductase proteins. Reduced iron is then taken up into the cell by a complex of a multicopper oxidase protein and an iron transport protein. Multicopper oxidase proteins require copper to function and so reductive iron and copper uptake are inextricably linked. It has previously been established that Fre10 is the major cell surface ferric reductase in C. albicans and that transcription of FRE10 is regulated in response to iron levels. We demonstrate here that Fre10 is also a cupric reductase and that Fre7 also makes a significant contribution to cell surface ferric and cupric reductase activity. It is also shown, for the first time, that transcription of FRE10 and FRE7 is lower in hyphae compared to yeast and that this leads to a corresponding decrease in cell surface ferric, but not cupric, reductase activity. This demonstrates that the regulation of two virulence determinants, the reductive iron uptake system and the morphological form of C. albicans, are linked. Copyright © 2011 John Wiley & Sons, Ltd.

  12. Enrichment of Multilocus Sequence Typing Clade 1 with Oral Candida albicans Isolates in Patients with Untreated Periodontitis

    Science.gov (United States)

    McManus, Brenda A.; Maguire, Rory; Cashin, Phillipa J.; Claffey, Noel; Flint, Stephen; Abdulrahim, Mohammed H.

    2012-01-01

    This study investigated the prevalence and cell density of Candida species in periodontal pockets, healthy subgingival sites, and oral rinse samples of patients with untreated periodontitis. Twenty-one periodontitis patients underwent sampling at two periodontitis sites, and 19/21 of these patients underwent sampling at one periodontally healthy site. Both paper point and curette sampling techniques were employed. The periodontitis patients and 50 healthy subjects were also sampled by oral rinse. Candida isolates were recovered on CHROMagar Candida medium, and representative isolates were identified. Candida spp. were recovered from 10/21 (46.7%) periodontitis patients and from 16/50 (32%) healthy subjects. C. albicans predominated in both groups and was recovered from all Candida-positive subjects. Candida-positive periodontitis patients yielded Candida from periodontal pockets with average densities of 3,528 and 3,910 CFU/sample from curette and paper point samples, respectively, and 1,536 CFU/ml from oral rinse samples. The majority (18/19) of the healthy sites sampled from periodontitis patients were Candida negative. The 16 Candida-positive healthy subjects yielded an average of 279 CFU/ml from oral rinse samples. C. albicans isolates were investigated by multilocus sequence typing (MLST) to determine if specific clonal groups were associated with periodontitis. MLST analysis of 31 C. albicans isolates from periodontitis patients yielded 19 sequence types (STs), 13 of which were novel. Eleven STs belonged to MLST clade 1. In contrast, 16 C. albicans isolates from separate healthy subjects belonged to 16 STs, with 4 isolates belonging to clade 1. The distributions of STs between both groups were significantly different (P = 0.04) and indicated an enrichment of C. albicans isolates in periodontal pockets, which warrants a larger study. PMID:22875886

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

    International Nuclear Information System (INIS)

    Salgado, Paula S.; Yan, Robert; Rowan, Fiona; Cota, Ernesto

    2011-01-01

    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 P2 1 2 1 2 1 , 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

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

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    E Farahbakhsh

    2011-08-01

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

  15. Candida albicans orf19.3727 encodes phytase activity and is essential for human tissue damage

    Science.gov (United States)

    Fong, Wing-Ping; Samaranayake, Lakshman Perera

    2017-01-01

    Candida albicans is a clinically important human fungal pathogen. We previously identified the presence of cell-associated phytase activity in C. albicans. Here, we reveal for the first time, that orf19.3727 contributes to phytase activity in C. albicans and ultimately to its virulence potency. Compared with its wild type counterpart, disruption of C. albicans orf19.3727 led to decreased phytase activity, reduced ability to form hyphae, attenuated in vitro adhesion, and reduced ability to penetrate human epithelium, which are the major virulence attributes of this yeast. Thus, orf19.3727 of C. albicans plays a key role in fungal pathogenesis. Further, our data uncover a putative novel strategy for anti-Candidal drug design through inhibition of phytase activity of this common pathogen. PMID:29216308

  16. The metabolic response of Candida albicans to farnesol under hyphae-inducing conditions.

    Science.gov (United States)

    Han, Ting-Li; Cannon, Richard D; Villas-Bôas, Silas G

    2012-12-01

    Farnesol is a quorum-sensing molecule (QSM) produced, and sensed, by the polymorphic fungus, Candida albicans. This cell-to-cell communication molecule is known to suppress the hyphal formation of C. albicans at high cell density. Despite many studies investigating the signalling mechanisms by which QSMs influence the morphogenesis of C. albicans, the downstream metabolic effect of these signalling pathways in response to farnesol-mediated morphogenesis remains obscure. Here, we have used metabolomics to investigate the metabolic response of C. albicans upon exposure to farnesol under hyphae-inducing conditions. We have found a general up-regulation of central carbon metabolic pathways when hyphal formation was suppressed by farnesol evidenced by a considerably larger number of central carbon metabolic intermediates detected under this condition at an overall lower intracellular level. By combining the metabolic profiles from farnesol-exposed cells with previous metabolomics data for C. albicans undergoing morphogenesis, we have identified several metabolic pathways that are likely to be associated with the morphogenetic process of C. albicans, as well as metabolic pathways such as those involved in lipid metabolism that appeared to be specifically affected by farnesol. Therefore, our results provide important new insights into the metabolic role of farnesol in C. albicans metabolism. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  17. 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.

  18. Dynamic, morphotype-specific Candida albicans beta-glucan exposure during infection and drug treatment.

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    Robert T Wheeler

    2008-12-01

    Full Text Available Candida albicans, a clinically important dimorphic fungal pathogen that can evade immune attack by masking its cell wall beta-glucan from immune recognition, mutes protective host responses mediated by the Dectin-1 beta-glucan receptor on innate immune cells. Although the ability of C. albicans to switch between a yeast- or hyphal-form is a key virulence determinant, the role of each morphotype in beta-glucan masking during infection and treatment has not been addressed. Here, we show that during infection of mice, the C. albicans beta-glucan is masked initially but becomes exposed later in several organs. At all measured stages of infection, there is no difference in beta-glucan exposure between yeast-form and hyphal cells. We have previously shown that sub-inhibitory doses of the anti-fungal drug caspofungin can expose beta-glucan in vitro, suggesting that the drug may enhance immune activity during therapy. This report shows that caspofungin also mediates beta-glucan unmasking in vivo. Surprisingly, caspofungin preferentially unmasks filamentous cells, as opposed to yeast form cells, both in vivo and in vitro. The fungicidal activity of caspofungin in vitro is also filament-biased, as corroborated using yeast-locked and hyphal-locked mutants. The uncloaking of filaments is not a general effect of anti-fungal drugs, as another anti-fungal agent does not have this effect. These results highlight the advantage of studying host-pathogen interaction in vivo and suggest new avenues for drug development.

  19. Candida albicans mannans mediate Streptococcus mutans exoenzyme GtfB binding to modulate cross-kingdom biofilm development in vivo.

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    Hwang, Geelsu; Liu, Yuan; Kim, Dongyeop; Li, Yong; Krysan, Damian J; Koo, Hyun

    2017-06-01

    Candida albicans is frequently detected with heavy infection by Streptococcus mutans in plaque-biofilms from children with early-childhood caries (ECC). This cross-kingdom biofilm contains an extensive matrix of extracellular α-glucans that is produced by an exoenzyme (GtfB) secreted by S. mutans. Here, we report that mannans located on the outer surface of C. albicans cell-wall mediates GtfB binding, enhancing glucan-matrix production and modulating bacterial-fungal association within biofilms formed in vivo. Using single-molecule atomic force microscopy, we determined that GtfB binds with remarkable affinity to mannans and to the C. albicans surface, forming a highly stable and strong bond (1-2 nN). However, GtfB binding properties to C. albicans was compromised in strains defective in O-mannan (pmt4ΔΔ) or N-mannan outer chain (och1ΔΔ). In particular, the binding strength of GtfB on och1ΔΔ strain was severely disrupted (>3-fold reduction vs. parental strain). In turn, the GtfB amount on the fungal surface was significantly reduced, and the ability of C. albicans mutant strains to develop mixed-species biofilms with S. mutans was impaired. This phenotype was independent of hyphae or established fungal-biofilm regulators (EFG1, BCR1). Notably, the mechanical stability of the defective biofilms was weakened, resulting in near complete biomass removal by shear forces. In addition, these in vitro findings were confirmed in vivo using a rodent biofilm model. Specifically, we observed that C. albicans och1ΔΔ was unable to form cross-kingdom biofilms on the tooth surface of rats co-infected with S. mutans. Likewise, co-infection with S. mutans defective in GtfB was also incapable of forming mixed-species biofilms. Taken together, the data support a mechanism whereby S. mutans-secreted GtfB binds to the mannan layer of C. albicans to promote extracellular matrix formation and their co-existence within biofilms. Enhanced understanding of GtfB-Candida interactions

  20. Genomic and Phenotypic Variation in Morphogenetic Networks of Two Candida albicans Isolates Subtends Their Different Pathogenic Potential

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    Duccio Cavalieri

    2018-01-01

    Full Text Available The transition from commensalism to pathogenicity of Candida albicans reflects both the host inability to mount specific immune responses and the microorganism’s dimorphic switch efficiency. In this study, we used whole genome sequencing and microarray analysis to investigate the genomic determinants of the phenotypic changes observed in two C. albicans clinical isolates (YL1 and YQ2. In vitro experiments employing epithelial, microglial, and peripheral blood mononuclear cells were thus used to evaluate C. albicans isolates interaction with first line host defenses, measuring adhesion, susceptibility to phagocytosis, and induction of secretory responses. Moreover, a murine model of peritoneal infection was used to compare the in vivo pathogenic potential of the two isolates. Genome sequence and gene expression analysis of C. albicans YL1 and YQ2 showed significant changes in cellular pathways involved in environmental stress response, adhesion, filamentous growth, invasiveness, and dimorphic transition. This was in accordance with the observed marked phenotypic differences in biofilm production, dimorphic switch efficiency, cell adhesion, invasion, and survival to phagocyte-mediated host defenses. The mutations in key regulators of the hyphal growth pathway in the more virulent strain corresponded to an overall greater number of budding yeast cells released. Compared to YQ2, YL1 consistently showed enhanced pathogenic potential, since in vitro, it was less susceptible to ingestion by phagocytic cells and more efficient in invading epithelial cells, while in vivo YL1 was more effective than YQ2 in recruiting inflammatory cells, eliciting IL-1β response and eluding phagocytic cells. Overall, these results indicate an unexpected isolate-specific variation in pathways important for host invasion and colonization, showing how the genetic background of C. albicans may greatly affect its behavior both in vitro and in vivo. Based on this approach, we

  1. Modelling the host-pathogen interactions of macrophages and Candida albicans using Game Theory and dynamic optimization.

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    Dühring, Sybille; Ewald, Jan; Germerodt, Sebastian; Kaleta, Christoph; Dandekar, Thomas; Schuster, Stefan

    2017-07-01

    The release of fungal cells following macrophage phagocytosis, called non-lytic expulsion, is reported for several fungal pathogens. On one hand, non-lytic expulsion may benefit the fungus in escaping the microbicidal environment of the phagosome. On the other hand, the macrophage could profit in terms of avoiding its own lysis and being able to undergo proliferation. To analyse the causes of non-lytic expulsion and the relevance of macrophage proliferation in the macrophage- Candida albicans interaction, we employ Evolutionary Game Theory and dynamic optimization in a sequential manner. We establish a game-theoretical model describing the different strategies of the two players after phagocytosis. Depending on the parameter values, we find four different Nash equilibria and determine the influence of the systems state of the host upon the game. As our Nash equilibria are a direct consequence of the model parameterization, we can depict several biological scenarios. A parameter region, where the host response is robust against the fungal infection, is determined. We further apply dynamic optimization to analyse whether macrophage mitosis is relevant in the host-pathogen interaction of macrophages and C. albicans For this, we study the population dynamics of the macrophage- C. albicans interactions and the corresponding optimal controls for the macrophages, indicating the best macrophage strategy of switching from proliferation to attacking fungal cells. © 2017 The Author(s).

  2. Curcumin uptake enhancement using low dose light illumination during incubation in Candida albicans

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    Romano, Renan A.; Pratavieira, Sebastião.; da Silva, Ana P.; Kurachi, Cristina; Bagnato, Vanderlei S.; Guimarães, Francisco E. G.

    2017-07-01

    A new PDI protocol is presented in this study. C. albicans cells pre-illuminated with a low dose light demonstrated an increase of curcumin uptake when compared to dark incubation, leading to a higher PDI efficacy.

  3. Inhibitors of the glyoxylate cycle enzyme ICL1 in Candida albicans for potential use as antifungal agents.

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    Hong-Leong Cheah

    Full Text Available Candida albicans is an opportunistic pathogen that causes candidiasis in humans. In recent years, metabolic pathways in C. albicans have been explored as potential antifungal targets to treat candidiasis. The glyoxylate cycle, which enables C. albicans to survive in nutrient-limited host niches and its. Key enzymes (e.g., isocitrate lyase (ICL1, are particularly attractive antifungal targets for C. albicans. In this study, we used a new screening approach that better reflects the physiological environment that C. albicans cells experience during infection to identify potential inhibitors of ICL. Three compounds (caffeic acid (CAFF, rosmarinic acid (ROS, and apigenin (API were found to have antifungal activity against C. albicans when tested under glucose-depleted conditions. We further confirmed the inhibitory potential of these compounds against ICL using the ICL enzyme assay. Lastly, we assessed the bioavailability and toxicity of these compounds using Lipinski's rule-of-five and ADMET analysis.

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

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

    2017-07-01

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

  5. Oral Immunization Against Candidiasis Using Lactobacillus casei Displaying Enolase 1 from Candida albicans

    OpenAIRE

    Shibasaki, Seiji; Karasaki, Miki; Tafuku, Senji; Aoki, Wataru; Sewaki, Tomomitsu; Ueda, Mitsuyoshi

    2014-01-01

    Abstract Candidiasis is a common fungal infection that is prevalent in immunocompromised individuals. In this study, an oral vaccine against Candida albicans was developed by using the molecular display approach. Enolase 1 protein (Eno1p) of C. albicans was expressed on the Lactobacillus casei cell surface by using poly-gamma-glutamic acid synthetase complex A from Bacillus subtilis as an anchoring protein. The Eno1p-displaying L. casei cells were used to immunize mice, which were later chall...

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

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    Ria Puspitawati

    2011-06-01

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

  7. Proper Sterol Distribution Is Required for Candida albicans Hyphal Formation and Virulence

    OpenAIRE

    McCourt, Paula; Liu, Hsing-Yin; Parker, Josie E.; Gallo-Ebert, Christina; Donigan, Melissa; Bata, Adam; Giordano, Caroline; Kelly, Steven L.; Nickels, Joseph T.

    2016-01-01

    Candida albicans is an opportunistic fungus responsible for the majority of systemic fungal infections. Multiple factors contribute to C. albicans pathogenicity. C. albicans strains lacking CaArv1 are avirulent. Arv1 has a conserved Arv1 homology domain (AHD) that has a zinc-binding domain containing two cysteine clusters. Here, we explored the role of the CaAHD and zinc-binding motif in CaArv1-dependent virulence. Overall, we found that the CaAHD was necessary but not sufficient for cells to...

  8. Minocycline Inhibits Candida albicans Budded-to-Hyphal-Form Transition and Biofilm Formation.

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    Kurakado, Sanae; Takatori, Kazuhiko; Sugita, Takashi

    2017-09-25

    Candida albicans frequently causes bloodstream infections; its budded-to-hyphalform transition (BHT) and biofilm formation are major contributors to virulence. During an analysis of antibacterial compounds that inhibit C. albicans BHT, we found that the tetracycline derivative minocycline inhibited BHT and subsequent biofilm formation. Minocycline decreased expression of hypha-specific genes HWP1 and ECE1, and adhesion factor gene ALS3 of C. albicans. In addition, minocycline decreased cell surface hydrophobicity and the extracellular β-glucan level in biofilms. Minocycline has been widely used for catheter antibiotic lock therapy to prevent bacterial infection; this compound may also be prophylactically effective against Candida infection.

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

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    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

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

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

    2012-06-01

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

  11. Candida albicans adherence to resin-composite restorative dental material: influence of whole human saliva.

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    Maza, José Luis; Elguezabal, Natalia; Prado, Carlota; Ellacuría, Joseba; Soler, Iñaki; Pontón, José

    2002-11-01

    Attachment of Candida albicans to oral surfaces is believed to be a critical event in the colonization of the oral cavity and in the development of oral diseases such as Candida-associated denture stomatitis. Although there is considerable information about the adhesion of C albicans to buccal epithelial cells and prosthetic materials, there is very little information about the adhesion of C albicans to composite restorative materials. The purpose of this study was to investigate the degree of adhesion of C albicans to a resin-composite restorative material (Herculite). The adhesion of 2 strains of C albicans, a germinative and a germ tube-deficient mutant, was studied by a visual method after incubating the fungus and the resin with and without human whole saliva. In absence of saliva, the adhesion of the C albicans germinative isolate to the resin showed an increase in parallel with the germination, reaching a maximum at the end of the experiment (120 minutes). However, no significant differences were observed in the adhesion of the agerminative mutant during the period of time studied. In the presence of saliva, the adhesion of both isolates to the resin was significantly lowered. Germination and the presence of human whole saliva are important factors in the adhesion of C albicans to the resin-composite restorative material Herculite.

  12. Release of lysosomal enzymes in Candida albicans phagocytosis by rat peritoneal macrophages.

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    Fontenla de Petrino, S E; Sirena, A

    1984-02-15

    The present paper reports the in vitro release of lysosomal enzymes in the supernatant of cultures of rat peritoneal macrophages, with the addition of Candida albicans cells. Macrophages were taken from the rat peritoneal cavity 72 hr after non-specific activation with Brain-Heart-Infusion (B.H.I.) broth containing 10% proteose-peptone No. 3. They were then cultured in Parker medium No. 199 (TC 199). After 24 hr a suspension of Candida albicans cells, in a determined concentration, was added to the peritoneal macrophage cultures. At that time, and during pre-determined periods, the following enzymes in the culture supernatants were studied using colorimetric methods: beta-glucuronidase, beta-galactosidase and acid phosphatase. It is concluded that, under identical conditions, the release of beta-galactosidase and acid phosphatase is higher than for beta-glucuronidase. The release rate of all three enzymes is the highest at a 6 hr incubation period, after which, a gradual decrease leads to the rate down to 50% at 24 hr.

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

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

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    Kong, Eric F.; Tsui, Christina; Kucharíková, Sona; Andes, David

    2016-01-01

    ABSTRACT Biofilm-associated polymicrobial infections, particularly those involving fungi and bacteria, are responsible for significant morbidity and mortality and tend to be challenging to treat. Candida albicans and Staphylococcus aureus specifically are considered leading opportunistic fungal and bacterial pathogens, respectively, mainly due to their ability to form biofilms on catheters and indwelling medical devices. However, the impact of mixed-species biofilm growth on therapy remains largely understudied. In this study, we investigated the influence of C. albicans secreted cell wall polysaccharides on the response of S. aureus to antibacterial agents in biofilm. Results demonstrated significantly enhanced tolerance for S. aureus to drugs in the presence of C. albicans or its secreted cell wall polysaccharide material. Fluorescence confocal time-lapse microscopy revealed impairment of drug diffusion through the mixed biofilm matrix. Using C. albicans mutant strains with modulated cell wall polysaccharide expression, exogenous supplementation, and enzymatic degradation, the C. albicans-secreted β-1,3-glucan cell wall component was identified as the key matrix constituent providing the bacteria with enhanced drug tolerance. Further, antibody labeling demonstrated rapid coating of the bacteria by the C. albicans matrix material. Importantly, via its effect on the fungal biofilm matrix, the antifungal caspofungin sensitized the bacteria to the drugs. Understanding such symbiotic interactions with clinical relevance between microbial species in biofilms will greatly aid in overcoming the limitations of current therapies and in defining potential new targets for treating polymicrobial infections. PMID:27729510

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

    Science.gov (United States)

    Fox, Emily P; Cowley, Elise S; Nobile, Clarissa J; Hartooni, Nairi; Newman, Dianne K; Johnson, Alexander D

    2014-10-20

    The human microbiome contains diverse microorganisms, which share and compete for the same environmental niches. A major microbial growth form in the human body is the biofilm state, where tightly packed bacterial, archaeal, and fungal cells must cooperate and/or compete for resources in order to survive. We examined mixed biofilms composed of the major fungal species of the gut microbiome, Candida albicans, and each of five prevalent bacterial gastrointestinal inhabitants: Bacteroides fragilis, Clostridium perfringens, Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. We observed that biofilms formed by C. albicans provide a hypoxic microenvironment that supports the growth of two anaerobic bacteria, even when cultured in ambient oxic conditions that are normally toxic to the bacteria. We also found that coculture with bacteria in biofilms induces massive gene expression changes in C. albicans, including upregulation of WOR1, which encodes a transcription regulator that controls a phenotypic switch in C. albicans, from the "white" cell type to the "opaque" cell type. Finally, we observed that in suspension cultures, C. perfringens induces aggregation of C. albicans into "mini-biofilms," which allow C. perfringens cells to survive in a normally toxic environment. This work indicates that bacteria and C. albicans interactions modulate the local chemistry of their environment in multiple ways to create niches favorable to their growth and survival. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2017-05-01

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

  17. [Sensitivity to disinfectants of Candid albicans strains isolated from the hospital environment].

    Science.gov (United States)

    Tadeusiak, B

    1998-01-01

    In recent years an increase of the incidence of Candida infections caused mainly by C. albicans strains especially in high risk inpatients with neoplasms, decreased immunity, burns and after treatment with multiple antibiotics has been observed. Candida organisms are particularly dangerous for newborns being responsible for about 30% of septicaemia cases in newborns in intensive care units. Fungal infections can be endogenous in origin but exogenous infection sources occur in hospitals. The cause of the latter are errors in aseptic management and insufficiently disinfected medical instruments and equipment. The purpose of the study was a comparison of the sensitivity to disinfectants of C. albicans belonging to two laboratory strains C. albicans PZH and C. albicans ATCC 10231 used for the determination of concentrations of two disinfectants used. Besides that, this sensitivity was determined in 14 strains isolated from the patients and one from the circuit of dialysis solution supply to artificial kidney. The study was carried out by the qualitative suspension method, in which the cells in the fluid were subjected to the action of disinfectants, and by the carrier method in which the cells of the microorganisms were present on the surface of metal cylinders. By the suspension method the sensitivity was determined to chloramine T in concentrations from 5.0% to 0.001%, formalin from 10.0% to 0.25%, glutaraldehyde from 2.0% to 0.1%, Septyl from 3.5% to 0.25%. The exposure time was 5, 10, 15, 30 and 60 minutes. The tested strains differed in their sensitivity to the disinfectants used. The greatest interstrain differences were observed in the sensitivity to the disinfectants used. The greatest interstrain differences were observed in the sensitivity to chloramine T. The highest concentrations were tolerated by the strains isolated from the patients and from the artificial kidney circuit as well as by the standard strain ATCC 10231. In the 10-minute exposure time

  18. Probiotic Bacteria Alter Pattern-Recognition Receptor Expression and Cytokine Profile in a Human Macrophage Model Challenged with Candida albicans and Lipopolysaccharide

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    Victor H. Matsubara

    2017-11-01

    Full Text Available Probiotics are live microorganisms that confer benefits to the host health. The infection rate of potentially pathogenic organisms such as Candida albicans, the most common agent associated with mucosal candidiasis, can be reduced by probiotics. However, the mechanisms by which the probiotics interfere with the immune system are largely unknown. We evaluated the effect of probiotic bacteria on C. albicans challenged human macrophages. Macrophages were pretreated with lactobacilli alone (Lactobacillus rhamnosus LR32, Lactobacillus casei L324m, or Lactobacillus acidophilus NCFM or associated with Escherichia coli lipopolysaccharide (LPS, followed by the challenge with C. albicans or LPS in a co-culture assay. The expression of pattern-recognition receptors genes (CLE7A, TLR2, and TLR4 was determined by RT-qPCR, and dectin-1 reduced levels were confirmed by flow cytometry. The cytokine profile was determined by ELISA using the macrophage cell supernatant. Overall probiotic lactobacilli down-regulated the transcription of CLEC7A (p < 0.05, resulting in the decreased expression of dectin-1 on probiotic pretreated macrophages. The tested Lactobacillus species down-regulated TLR4, and increased TLR2 mRNA levels in macrophages challenged with C. albicans. The cytokines profile of macrophages challenged with C. albicans or LPS were altered by the probiotics, which generally led to increased levels of IL-10 and IL-1β, and reduction of IL-12 production by macrophages (p < 0.05. Our data suggest that probiotic lactobacilli impair the recognition of PAMPs by macrophages, and alter the production of pro/anti-inflammatory cytokines, thus modulating inflammation.

  19. A trypsin inhibitor from Tecoma stans leaves inhibits growth and promotes ATP depletion and lipid peroxidation in Candida albicans and Candida krusei

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    Leydianne Leite de Siqueira Patriota

    2016-04-01

    Full Text Available 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 sulphate 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.

  20. Small molecule inhibitors of the Candida albicans budded-to-hyphal transition act through multiple signaling pathways.

    Directory of Open Access Journals (Sweden)

    John Midkiff

    Full Text Available The ability of the pathogenic yeast Candida albicans to interconvert between budded and hyphal growth states, herein termed the budded-to-hyphal transition (BHT, is important for C. albicans development and virulence. The BHT is under the control of multiple cell signaling pathways that respond to external stimuli, including nutrient availability, high temperature, and pH. Previous studies identified 21 small molecules that could inhibit the C. albicans BHT in response to carbon limitation in Spider media. However, the studies herein show that the BHT inhibitors had varying efficacies in other hyphal-inducing media, reflecting their varying abilities to block signaling pathways associated with the different media. Chemical epistasis analyses suggest that most, but not all, of the BHT inhibitors were acting through either the Efg1 or Cph1 signaling pathways. Notably, the BHT inhibitor clozapine, a FDA-approved drug used to treat atypical schizophrenia by inhibiting G-protein-coupled dopamine receptors in the brain, and several of its functional analogs were shown to act at the level of the Gpr1 G-protein-coupled receptor. These studies are the first step in determining the target and mechanism of action of these BHT inhibitors, which may have therapeutic anti-fungal utility in the future.

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

    International Nuclear Information System (INIS)

    Gil, C.; Pomes, R.; Nombela, C.

    1990-01-01

    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

  2. Antifungal activity of oligochitosans (short chain chitosans) against some Candida species and clinical isolates of Candida albicans: molecular weight-activity relationship.

    Science.gov (United States)

    Kulikov, Sergey N; Lisovskaya, Svetlana A; Zelenikhin, Pavel V; Bezrodnykh, Evgeniya A; Shakirova, Diana R; Blagodatskikh, Inesa V; Tikhonov, Vladimir E

    2014-03-03

    A series of oligochitosans (short chain chitosans) prepared by acidic hydrolysis of chitosan and characterized by their molecular weight, polydispersity and degree of deacetylation were used to determine their anticandidal activities. This study has demonstrated that oligochitosans show a high fungistatic activity (MIC 8-512 μg/ml) against Candida species and clinical isolates of Candida albicans, which are resistant to a series of classic antibiotics. Flow cytometry analysis showed that oligochitosan possessed a high fungicidal activity as well. For the first time it was shown that even sub-MIC oligochitosan concentration suppressed the formation of C. albicans hyphal structures, cause severe cell wall alterations, and altered internal cell structure. These results indicate that oligochitosan should be considered as a possible alternative/additive to known anti-yeast agents in pharmaceutical compositions. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  3. Antifungal and Anti-Biofilm Activities of Acetone Lichen Extracts against Candida albicans

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    Marion Millot

    2017-04-01

    Full Text Available Candida albicans is a commensal coloniser of the human gastrointestinal tract and an opportunistic pathogen, especially thanks to its capacity to form biofilms. This lifestyle is frequently involved in infections and increases the yeast resistance to antimicrobials and immune defenses. In this context, 38 lichen acetone extracts have been prepared and evaluated for their activity against C. albicans planktonic and sessile cells. Minimum inhibitory concentrations of extracts (MICs were determined using the broth microdilution method. Anti-biofilm activity was evaluated using tetrazolium salt (XTT assay as the ability to inhibit the maturation phase (anti-maturation or to eradicate a preformed 24 h old biofilm (anti-biofilm. While none of the extracts were active against planktonic cells, biofilm maturation was limited by 11 of the tested extracts. Seven extracts displayed both anti-maturation and anti-biofilm activities (half maximal inhibitory concentrations IC50_mat and IC50_biof ≤ 100 µg/mL; Evernia prunastri and Ramalina fastigiata were the most promising lichens (IC50_mat < 4 µg/mL and IC50_biof < 10 µg/mL. Chemical profiles of the active extracts performed by thin layer chromatography (TLC and high performance liquid chromatography (HPLC have been analyzed. Depsides, which were present in large amounts in the most active extracts, could be involved in anti-biofilm activities. This work confirmed that lichens represent a reservoir of compounds with anti-biofilm potential.

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

    Science.gov (United States)

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

    2016-01-01

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

  5. Candida Albicans and Non-Albicans Species as Etiological Agent of Vaginitis in Pregnant and Non-Pregnant Women

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    Mirela Babić

    2010-02-01

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

  6. Novel structural features in Candida albicans hyphal glucan provide a basis for differential innate immune recognition of hyphae versus yeast.

    Science.gov (United States)

    Lowman, Douglas W; Greene, Rachel R; Bearden, Daniel W; Kruppa, Michael D; Pottier, Max; Monteiro, Mario A; Soldatov, Dmitriy V; Ensley, Harry E; Cheng, Shih-Chin; Netea, Mihai G; Williams, David L

    2014-02-07

    The innate immune system differentially recognizes Candida albicans yeast and hyphae. It is not clear how the innate immune system effectively discriminates between yeast and hyphal forms of C. albicans. Glucans are major components of the fungal cell wall and key fungal pathogen-associated molecular patterns. C. albicans yeast glucan has been characterized; however, little is known about glucan structure in C. albicans hyphae. Using an extraction procedure that minimizes degradation of the native structure, we extracted glucans from C. albicans hyphal cell walls. (1)H NMR data analysis revealed that, when compared with reference (1→3,1→6) β-linked glucans and C. albicans yeast glucan, hyphal glucan has a unique cyclical or "closed chain" structure that is not found in yeast glucan. GC/MS analyses showed a high abundance of 3- and 6-linked glucose units when compared with yeast β-glucan. In addition to the expected (1→3), (1→6), and 3,6 linkages, we also identified a 2,3 linkage that has not been reported previously in C. albicans. Hyphal glucan induced robust immune responses in human peripheral blood mononuclear cells and macrophages via a Dectin-1-dependent mechanism. In contrast, C. albicans yeast glucan was a much less potent stimulus. We also demonstrated the capacity of C. albicans hyphal glucan, but not yeast glucan, to induce IL-1β processing and secretion. This finding provides important evidence for understanding the immune discrimination between colonization and invasion at the mucosal level. When taken together, these data provide a structural basis for differential innate immune recognition of C. albicans yeast versus hyphae.

  7. Metabolic response of Candida albicans to phenylethyl alcohol under hyphae-inducing conditions.

    Science.gov (United States)

    Han, Ting-Li; Tumanov, Sergey; Cannon, Richard D; Villas-Boas, Silas G

    2013-01-01

    Phenylethyl alcohol was one of the first quorum sensing molecules (QSMs) identified in C. albicans. This extracellular signalling molecule inhibits the hyphal formation of C. albicans at high cell density. Little is known, however, about the underlying mechanisms by which this QSM regulates the morphological switches of C. albicans. Therefore, we have applied metabolomics and isotope labelling experiments to investigate the metabolic changes that occur in C. albicans in response to phenylethyl alcohol under defined hyphae-inducing conditions. Our results showed a global upregulation of central carbon metabolism when hyphal development was suppressed by phenylethyl alcohol. By comparing the metabolic changes in response to phenylethyl alcohol to our previous metabolomic studies, we were able to short-list 7 metabolic pathways from central carbon metabolism that appear to be associated with C. albicans morphogenesis. Furthermore, isotope-labelling data showed that phenylethyl alcohol is indeed taken up and catabolised by yeast cells. Isotope-labelled carbon atoms were found in the majority of amino acids as well as in lactate and glyoxylate. However, isotope-labelled carbon atoms from phenylethyl alcohol accumulated mainly in the pyridine ring of NAD(+)/NADH and NADP(-/)NADPH molecules, showing that these nucleotides were the main products of phenylethyl alcohol catabolism. Interestingly, two metabolic pathways where these nucleotides play an important role, nitrogen metabolism and nicotinate/nicotinamide metabolism, were also short-listed through our previous metabolomics works as metabolic pathways likely to be closely associated with C. albicans morphogenesis.

  8. Antibiofilm and Antihyphal Activities of Cedar Leaf Essential Oil, Camphor, and Fenchone Derivatives against Candida albicans

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    Ranjith Kumar Manoharan

    2017-08-01

    Full Text Available Candida albicans can form biofilms composed of yeast, hyphal, and pseudohyphal elements, and C. albicans cells in the hyphal stage could be a virulence factor. The present study describes the chemical composition, antibiofilm, and antihyphal activities of cedar leaf essential oil (CLEO, which was found to possess remarkable antibiofilm activity against C. albicans but not to affect its planktonic cell growth. Nineteen components were identified in CLEO by gas chromatography/mass spectrometry, and phenolics were the main constituents. Of these, camphor, fenchone, fenchyl alcohol, α-thujone, and borneol significantly reduced C. albicans biofilm formation. Notably, treatments with CLEO, camphor, or fenchyl alcohol at 0.01% clearly inhibited hyphal formation, and this inhibition appeared to be largely responsible for their antibiofilm effects. Transcriptomic analyses indicated that camphor and fenchyl alcohol downregulated some hypha-specific and biofilm related genes (ECE1, ECE2, RBT1, and EED1. Furthermore, camphor and fenchyl alcohol reduced C. albicans virulence in a Caenorhabditis elegans nematode model. These results demonstrate CLEO, camphor, and fenchyl alcohol might be useful for controlling C. albicans infections.

  9. 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.

  10. Limonene inhibits Candida albicans growth by inducing apoptosis.

    Science.gov (United States)

    Thakre, Archana; Zore, Gajanan; Kodgire, Santosh; Kazi, Rubina; Mulange, Shradha; Patil, Rajendra; Shelar, Amruta; Santhakumari, Bayitigeri; Kulkarni, Mahesh; Kharat, Kiran; Karuppayil, Sankunny Mohan

    2018-07-01

    Anti-Candida potential of limonene was evaluated against planktonic growth, biofilm (adhesion, development and maturation) and morphogenesis of Candida albicans in this study. Limonene is a major constituent of citrus oil and most frequently used terpene in food and beverage industry due to its pleasant fragrance, nontoxic, and is generally recognized as safe (GRAS) flavoring agent as well as treatment option in many gastrointestinal diseases.Limonene exhibited excellent anti-Candida activity and was equally effective against planktonic growth of C. albicans isolates differentially susceptible to FLC (N = 35). Limonene inhibited morphogenesis significantly at low concentration. However, it showed stage dependent activity against biofilm formation, that is, it was more effective against adhesion followed by development and maturation. Limonene also exhibited excellent synergy with FLC against planktonic and biofilm growth. SWATH-MS analysis led to identification of limonene responsive proteins that provided molecular insight of its anti-Candida activity. Proteomic analysis revealed upregulation of proteins involved in cell wall glucan synthesis (Kre6); oxidative stress (Rhr2, Adh7 and Ebp1); DNA damage stress (Mbf1 and Npl3); nucleolar stress (Rpl11, Rpl7, Rpl29, Rpl15) and down regulation of cytoskeleton organization (Crn1, Pin3, Cct8, Rbl2), and so forth, in response to limonene. Limonene mediated down regulation of Tps3 indicates activation of caspase (CaMca1) and induction of apoptosis in C. albicans. These results suggest that limonene inhibits C. albicans growth by cell wall/membrane damage induced oxidative stress that leads to DNA damage resulting into modulation of cell cycle and induction of apoptosis through nucleolar stress and metacaspase dependent pathway.

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

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    E. L. Ribeiro

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

  12. Cell fate determination dynamics in bacteria

    Science.gov (United States)

    Kuchina, Anna; Espinar, Lorena; Cagatay, Tolga; Garcia-Ojalvo, Jordi; Suel, Gurol

    2010-03-01

    The fitness of an organism depends on many processes that serve the purpose to adapt to changing environment in a robust and coordinated fashion. One example of such process is cellular fate determination. In the presence of a variety of alternative responses each cell adopting a particular fate represents a ``choice'' that must be tightly regulated to ensure the best survival strategy for the population taking into account the broad range of possible environmental challenges. We investigated this problem in the model organism B.Subtilis which under stress conditions differentiates terminally into highly resistant spores or initiates an alternative transient state of competence. The dynamics underlying cell fate choice remains largely unknown. We utilize quantitative fluorescent microscopy to track the activities of genes involved in these responses on a single-cell level. We explored the importance of temporal interactions between competing cell fates by re- engineering the differentiation programs. I will discuss how the precise dynamics of cellular ``decision-making'' governed by the corresponding biological circuits may enable cells to adjust to diverse environments and determine survival.

  13. Deoxyribonucleic acid-deficient strains of Candida albicans.

    Science.gov (United States)

    Olaiya, A F; Steed, J R; Sogin, S J

    1980-03-01

    We analyzed a series of germ tube-negative variants isolated from Candida albicans 3153A for deoxyribonucleic acid content. As analyzed by flow microfluorometry, the deoxyribonucleic acid level in these variant strains was 50% of that of the parental strain and equivalent to that of haploid Saccharomyces cerevisiae. This finding was confirmed by comparison of survival rates when exposed to the mutagens ultraviolet light, ethyl methane sulfonate, and methyl methane sulfonate. The diameter of the variant cells as compared to the diameter of the parental 3153A strain showed a relationship similar to that of the diameters of haploid versus diploid S. cerevisiae. These results indicate that those strains may be representative of the imperfect stage of C. albicans.

  14. Studies on effect of Microbial Iron Chelators on Candida Albican

    International Nuclear Information System (INIS)

    Rehmani, Fouzia S.; Milicent, S.; Zaheer-Uddin

    2005-01-01

    Iron is an essential for the life of all microbe cells. It generally exists in the oxidized form Fe(III). Even under anaerobic reducing condition the metal appear to be taken up as Fe(III). Thus free-living microorganisms require specific and effective ferric ion transport system to cope with low availability of the metal. In iron deficient environment they produce a low molecular weight specific chelators called siderphores or microbial iron chelators. Siderphores compete for limited supplied of iron. These compounds came out of the cell but can not re-enter without iron due to high affinity of these siderphores often have more than one catechol/hydroxamate functions and are multidentate (usually hexadentate ligands). The aim of the present research is to check the effect of iron chelators, namely gallic acid and salisyl hydroxamate on the growth of Candida albican in vitro. C. albican is the opportunistic paltogen present as the normal flora inside human body. In vivo the growth of C. albican is distributed by the use of antibiotics and immuno suppressers. In cases of iron over-dosage in human being, the patients are treated with certain a-iron chelators. Hence an attempt is made to notice the effect that might be inhibition or enhancement of the organism in vitro. (author)

  15. An in vitro antifungal efficacy of silver nanoparticles activated by diode laser to Candida albicans

    Science.gov (United States)

    Astuti, S. D.; Kharisma, D. H.; Kholimatussa'diah, S.; Zaidan, A. H.

    2017-09-01

    Microbial infectious diseases and increased resistance to antibiotics become urgent problems requiring immediate solutions. One promising alternative is the using of silver nanoparticles. The combination of the microbial inhibition characteristic of silver nanotechnology enhances the activity of antimicrobial effect. This study aims to determine effectiveness of antifungal silver nanoparticles with the activation of the diode laser on Candida albicans. The samples were culture of Candida albicans. Candida albicans cultures were incubated with silver nanoparticles (concentration 10-4 M) and treated with various exposure time of diode laser (15, 30, 45, 60, 75, 90)s. The suspension was planted on Sabouraud Dextrone Agar sterile media and incubated for 24 hours at temperature of 37oC. The number of colony-forming units per milliliter (CFU/ml) was determined after incubation. The results were log-transformed and analyzed by analysis of variance (ANOVA). In this analysis, P value ≤0.05 was considered to indicate a statistically significant difference. The result of this study showed the quantum yield of silver nanoparticles with diode laser 450 nm was 63,61%. Irradiating with diode laser 450 nm for 75 s resulted in the highest decreasing percentage of Candida albicans viability 65,03%. Irradiating with diode laser 450 nm 75 s with silver nanoparticles resulted in the higest decreasing percentage of Candida albicans viability 84,63%. Therefore, silver nanoparticles activated with diode laser irradiation of 450 nm resulted antifungal effect to Candida albicans viability.

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

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    Hermina Karuna Atmaja

    2015-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Katarzyna M Tyc

    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.

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

    Science.gov (United States)

    Tyc, Katarzyna M.; Kühn, Clemens; Wilson, Duncan; Klipp, Edda

    2014-01-01

    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 modeling approach have potential application in developing treatment strategies. PMID:24567730

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

    International Nuclear Information System (INIS)

    Watanabe, Toshihiko; Ogasawara, Ayako; Mikami, Takeshi; Matsumoto, Tatsuji

    2006-01-01

    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

  20. Streptococcus agalactiae Inhibits Candida albicans Hyphal Development and Diminishes Host Vaginal Mucosal TH17 Response

    Directory of Open Access Journals (Sweden)

    Xiao-Yu Yu

    2018-02-01

    Full Text Available Streptococcus agalactiae and Candida albicans often co-colonize the female genital tract, and under certain conditions induce mucosal inflammation. The role of the interaction between the two organisms in candidal vaginitis is not known. In this study, we found that co-infection with S. agalactiae significantly attenuated the hyphal development of C. albicans, and that EFG1-Hwp1 signal pathway of C. albicans was involved in this process. In a mouse model of vulvovaginal candidiasis (VVC, the fungal burden and the levels of pro-inflammatory cytokines, IL-1β, IL-6 and TNF-α showed a increase on co-infection with S. agalactiae, while the level of TH17 T cells and IL-17 in the cervicovaginal lavage fluid were significantly decreased. Our results indicate that S. agalactiae inhibits C. albicans hyphal development by downregulating the expression of EFG1-Hwp1. The interaction between S. agalactiae and C. albicans may attenuate host vaginal mucosal TH17 immunity and contribute to mucosal colonization by C. albicans.

  1. Streptococcus agalactiae Inhibits Candida albicans Hyphal Development and Diminishes Host Vaginal Mucosal TH17 Response.

    Science.gov (United States)

    Yu, Xiao-Yu; Fu, Fei; Kong, Wen-Na; Xuan, Qian-Kun; Wen, Dong-Hua; Chen, Xiao-Qing; He, Yong-Ming; He, Li-Hua; Guo, Jian; Zhou, Ai-Ping; Xi, Yang-Hong; Ni, Li-Jun; Yao, Yu-Feng; Wu, Wen-Juan

    2018-01-01

    Streptococcus agalactiae and Candida albicans often co-colonize the female genital tract, and under certain conditions induce mucosal inflammation. The role of the interaction between the two organisms in candidal vaginitis is not known. In this study, we found that co-infection with S. agalactiae significantly attenuated the hyphal development of C. albicans , and that EFG1 -Hwp1 signal pathway of C. albicans was involved in this process. In a mouse model of vulvovaginal candidiasis (VVC), the fungal burden and the levels of pro-inflammatory cytokines, IL-1β, IL-6 and TNF-α showed a increase on co-infection with S. agalactiae , while the level of TH17 T cells and IL-17 in the cervicovaginal lavage fluid were significantly decreased. Our results indicate that S. agalactiae inhibits C. albicans hyphal development by downregulating the expression of EFG1 -Hwp1. The interaction between S. agalactiae and C. albicans may attenuate host vaginal mucosal TH17 immunity and contribute to mucosal colonization by C. albicans .

  2. Epithelial invasion outcompetes hypha development during Candida albicans infection as revealed by an image-based systems biology approach.

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    Mech, Franziska; Wilson, Duncan; Lehnert, Teresa; Hube, Bernhard; Thilo Figge, Marc

    2014-02-01

    Candida albicans is the most common opportunistic fungal pathogen of the human mucosal flora, frequently causing infections. The fungus is responsible for invasive infections in immunocompromised patients that can lead to sepsis. The yeast to hypha transition and invasion of host-tissue represent major determinants in the switch from benign colonizer to invasive pathogen. A comprehensive understanding of the infection process requires analyses at the quantitative level. Utilizing fluorescence microscopy with differential staining, we obtained images of C. albicans undergoing epithelial invasion during a time course of 6 h. An image-based systems biology approach, combining image analysis and mathematical modeling, was applied to quantify the kinetics of hyphae development, hyphal elongation, and epithelial invasion. The automated image analysis facilitates high-throughput screening and provided quantities that allow for the time-resolved characterization of the morphological and invasive state of fungal cells. The interpretation of these data was supported by two mathematical models, a kinetic growth model and a kinetic transition model, that were developed using differential equations. The kinetic growth model describes the increase in hyphal length and revealed that hyphae undergo mass invasion of epithelial cells following primary hypha formation. We also provide evidence that epithelial cells stimulate the production of secondary hyphae by C. albicans. Based on the kinetic transition model, the route of invasion was quantified in the state space of non-invasive and invasive fungal cells depending on their number of hyphae. This analysis revealed that the initiation of hyphae formation represents an ultimate commitment to invasive growth and suggests that in vivo, the yeast to hypha transition must be under exquisitely tight negative regulation to avoid the transition from commensal to pathogen invading the epithelium. © 2013 International Society for

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

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    Furletti, V F; Teixeira, I P; Obando-Pereda, G; Mardegan, R C; Sartoratto, A; Figueira, G M; Duarte, R M T; Rehder, V L G; Duarte, M C T; Höfling, J F

    2011-01-01

    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 F(8-10) 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 F(8-10) 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.

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

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    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.

  5. Competitive Fitness of Fluconazole-Resistant Clinical Candida albicans Strains.

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    Popp, Christina; Hampe, Irene A I; Hertlein, Tobias; Ohlsen, Knut; Rogers, P David; Morschhäuser, Joachim

    2017-07-01

    The pathogenic yeast Candida albicans can develop resistance to the widely used antifungal agent fluconazole, which inhibits ergosterol biosynthesis. Resistance is often caused by gain-of-function mutations in the transcription factors Mrr1 and Tac1, which result in constitutive overexpression of multidrug efflux pumps, and Upc2, which result in constitutive overexpression of ergosterol biosynthesis genes. However, the deregulated gene expression that is caused by hyperactive forms of these transcription factors also reduces the fitness of the cells in the absence of the drug. To investigate whether fluconazole-resistant clinical C. albicans isolates have overcome the fitness costs of drug resistance, we assessed the relative fitness of C. albicans isolates containing resistance mutations in these transcription factors in competition with matched drug-susceptible isolates from the same patients. Most of the fluconazole-resistant isolates were outcompeted by the corresponding drug-susceptible isolates when grown in rich medium without fluconazole. On the other hand, some resistant isolates with gain-of-function mutations in MRR1 did not exhibit reduced fitness under these conditions. In a mouse model of disseminated candidiasis, three out of four tested fluconazole-resistant clinical isolates did not exhibit a significant fitness defect. However, all four fluconazole-resistant isolates were outcompeted by the matched susceptible isolates in a mouse model of gastrointestinal colonization, demonstrating that the effects of drug resistance on in vivo fitness depend on the host niche. Collectively, our results indicate that the fitness costs of drug resistance in C. albicans are not easily remediated, especially when proper control of gene expression is required for successful adaptation to life within a mammalian host. Copyright © 2017 American Society for Microbiology.

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

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

    2014-08-01

    Ferrocene-substituted porphyrin RL-91 exhibits antifungal activity against opportune human pathogen Candida albicans. RL-91 efficiently inhibits growth of both planktonic C. albicans cells and cells within biofilms without photoactivation. The minimal inhibitory concentration for plankton form (PMIC) was established to be 100 μg/mL and the same concentration killed 80% of sessile cells in the mature biofilm (SMIC80). Furthermore PMIC of RL-91 efficiently prevents C. albicans biofilm formation. RL-91 is cytotoxic for human fibroblasts in vitro in concentration of 10 μg/mL, however it does not cause hemolysis in concentrations of up to 50 μg/mL. These findings open possibility for application of RL-91 as an antifungal agent for external antibiofilm treatment of medical devices as well as a scaffold for further development of porphyrin based systemic antifungals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Susceptibility of Candida albicans Isolated from Blood to Wickerhamomyces anomalous Mycocins.

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    Paris, Ana Paula; Persel, Cristiane; Serafin, Cleber Fernando; de Cássia Garcia Simão, Rita; Gandra, Rinaldo Ferreira

    2016-12-01

    The occurrence of infections caused by Candida albicans in developed and developing countries and their resistance to some available antifungal drugs have been viewed as causing a great problem to human health worldwide. In order to find new researched molecules, there are some mycoses secreted by yeasts, especially mycocins produced by Wickerhamomyces anomalus with a broad antimicrobial spectrum of activity. Thus, this trial aimed at evaluating mycocins' activity obtained from environmental W. anomalus cell wall compared to thirty C. albicans strains isolated from blood. Mycocins were extracted from cell walls of three W. anomalus strains (WA40, WA45, and WA92). The 400 μg mL -1 concentration of WA40M1, WA45M2, and WA92M3 mycocin extracts showed the following respective activity results: 96.6, 96.6, and 90.0 % C. albicans strains. WA45M2 and WA92M3 mycocin extracts showed some activity in 3.3 % of C. albicans strains at 50 μg mL -1 concentration. Mycocins extracted from cell walls of three W. anomalus strains named as WA40, WA45, and WA92 showed antifungal activity compared to C. albicans and low degree of hemolysis.

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

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    Anna Murzyn

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

  9. Capric Acid Secreted by S. boulardii Inhibits C. albicans Filamentous Growth, Adhesion and Biofilm Formation

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    Murzyn, Anna; Krasowska, Anna; Stefanowicz, Piotr; Dziadkowiec, Dorota; Łukaszewicz, Marcin

    2010-01-01

    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 biofilm formation. PMID

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

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    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. Simvastatin inhibits Candida albicans biofilm in vitro.

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    Liu, Geoffrey; Vellucci, Vincent F; Kyc, Stephanie; Hostetter, Margaret K

    2009-12-01

    By inhibiting the conversion of 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) to mevalonate, statins impair cholesterol metabolism in humans. We reasoned that statins might similarly interfere with the biosynthesis of ergosterol, the major sterol of the yeast cell membrane. As assessed by spectrophotometric and microscopic analysis, significant inhibition of biofilm production was noted after 16-h incubation with 1, 2.5, and 5 muM simvastatin, concentrations that did not affect growth, adhesion, or hyphal formation by C. albicans in vitro. Higher concentrations (10, 20, and 25 muM simvastatin) inhibited biofilm by >90% but also impaired growth. Addition of exogenous ergosterol (90 muM) overcame the effects of 1 and 2.5 muM simvastatin, suggesting that at least one mechanism of inhibition is interference with ergosterol biosynthesis. Clinical isolates from blood, skin, and mucosal surfaces produced biofilms; biofilms from bloodstream isolates were similarly inhibited by simvastatin. In the absence of fungicidal activity, simvastatin's interruption of a critical step in an essential metabolic pathway, highly conserved from yeast to man, has unexpected effects on biofilm production by a eukaryotic pathogen.

  12. [Pulsatilla decoction inhibits vulvovaginal Candida albicans proliferation and reduces inflammatory cytokine levels in vulvovaginal candidiasis mice].

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    Xia, Dan; Zhang, Mengxiang; Shi, Gaoxiang; Xu, Zhiqing; Wu, Daqiang; Shao, Jing; Wang, Tianming; Wang, Changzhong

    2016-02-01

    To explore the possible regulatory effect of Pulsatilla decoction on Th17 cells and inflammatory cytokines of vulvovaginal candidiasis (VVC) mice. Seventy-two female Kunming mice were randomly assigned into six groups: a blank control group, a VVC model group, a fluconazole group and three Pulsatilla decoction groups (dose levels: 22.5, 15.0 and 7.5 g/kg, respectively). The VVC mouse models were established by vaginal inoculation with Candida albicans (C. albicans) in female mice in pseudoestrus state caused by estradiol injection. After 7-day treatment on VVC mice, the vaginal C. albicans burden was assessed using dilution spread plate method; the vaginal C. albicans morphology was observed by Gram staining method; the levels of interleukin 6 (IL-6), IL-17, IL-21 and tumor necrosis factor α (TNF-α) in sera were detected by ELISA. The content of the transcription factor retinoid related orphan receptor gamma t (RORγt) in vaginal tissues was detected by immunohistochemistry. The VVC mouse models were successfully developed. After treatment, the vaginal C. albicans burden of the fluconazole group and 22.5 g/kg Pulsatilla decoction group dropped significantly compared with that of the VVC model group. Gram staining showed that the VVC mice had lots of C. albicans hyphae in vaginal discharge, that 7.5 g/kg Pulsatilla decoction group remained the mycelia-phase C. albicans, and that 15.0 g/kg Pulsatilla decoction group had the majority of yeast-phase C. albicans and a few of mycelia-phase, while no hyphae and only very few of yeast-phase C. albicans were observed in 22.5 g/kg Pulsatilla decoction group and fluconazole group. After 7-day treatment, compared with the model group, the levels of IL-6, IL- 17, IL-21 and TNF-α in the sera of the fluconazole group, 15.0 and 22.5 g/kg Pulsatilla decoction groups were reduced significantly and the levels of RORγt in the vaginal tissues of the fluconazole group, 15.0 and 22.5 g/kg Pulsatilla decoction groups also decreased

  13. Genetic Control of Conventional and Pheromone-Stimulated Biofilm Formation in Candida albicans

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

    2013-01-01

    Candida albicans can stochastically switch between two phenotypes, white and opaque. Opaque cells are the sexually competent form of C. albicans and therefore undergo efficient polarized growth and mating in the presence of pheromone. In contrast, white cells cannot mate, but are induced – under a specialized set of conditions – to form biofilms in response to pheromone. In this work, we compare the genetic regulation of such “pheromone-stimulated” biofilms with that of “conventional” C. albicans biofilms. In particular, we examined a network of six transcriptional regulators (Bcr1, Brg1, Efg1, Tec1, Ndt80, and Rob1) that mediate conventional biofilm formation for their potential roles in pheromone-stimulated biofilm formation. We show that four of the six transcription factors (Bcr1, Brg1, Rob1, and Tec1) promote formation of both conventional and pheromone-stimulated biofilms, indicating they play general roles in cell cohesion and biofilm development. In addition, we identify the master transcriptional regulator of pheromone-stimulated biofilms as C. albicans Cph1, ortholog of Saccharomyces cerevisiae Ste12. Cph1 regulates mating in C. albicans opaque cells, and here we show that Cph1 is also essential for pheromone-stimulated biofilm formation in white cells. In contrast, Cph1 is dispensable for the formation of conventional biofilms. The regulation of pheromone- stimulated biofilm formation was further investigated by transcriptional profiling and genetic analyses. These studies identified 196 genes that are induced by pheromone signaling during biofilm formation. One of these genes, HGC1, is shown to be required for both conventional and pheromone-stimulated biofilm formation. Taken together, these observations compare and contrast the regulation of conventional and pheromone-stimulated biofilm formation in C. albicans, and demonstrate that Cph1 is required for the latter, but not the former. PMID:23637598

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

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    Whibley, Natasha; Gaffen, Sarah L.

    2015-01-01

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

  15. Treatment of serum with supernatants from cultures of Candida albicans reduces its serum-dependent phagocytosis Tratamento de soro com sobrenadante de cultura de Candida albicans reduz a fagocitose soro-dependente

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    Aderbal Antonio dos Santos

    2002-01-01

    Full Text Available Candida albicans is a potent activator of the complement system, and heat labile opsonins produced by activation of C3 (C3b and iC3b enhance phagocytosis of C. albicans mediated by complement receptors. In this study we treated mouse serum with supernatants from cultures of a protease producer strain of C. albicans and evaluated the ability of this serum to enhance phagocytosis of C. albicans. Cell-free supernatants from cultures of C. albicans were concentrated 5 fold and added to mouse serum for 30 min at 37ºC, before using this serum for opsonization of glutaraldehyde-fixed yeast cells. We observed that normal mouse serum increased about 3 fold the phagocytosis of C. albicans by mice peritoneal macrophages, whereas supernatant-treated serum did not increase phagocytosis. This effect of supernatants on serum was prevented by addition of pepstatin (5 µg/ ml; an inhibitor of C. albicans acid proteases to the medium. Serum treated with supernatants from cultures of a protease-deficient mutant of C. albicans also increased about 3 fold phagocytosis of the yeast. These results suggest that a protease produced by C. albicans causes proteolysis of serum opsonins, thereby reducing the phagocytosis of the yeast.Candida albicans é um potente ativador do sistema complemento, e opsoninas lábeis ao calor produzidas por ativação de C3 (C3b e iC3b aumentam a fagocitose de C. albicans mediada por receptores de complemento. Neste estudo, tratamos o soro de camundongo com sobrenadante de culturas de uma cepa de C. albicans produtora de proteases e avaliamos a capacidade deste soro reduzir a fagocitose de C. albicans. Sobrenadantes livres de células obtidos de cultura de C. albicans foram concentrados 5 vezes e adicionados ao soro de camundongo por 30 minutos a 37ºC, antes deste soro ser usado para opsonização de C. albicans na forma de levedura e fixadas em glutaraldeido. Nós observamos que soro normal aumentou 3 vezes a fagocitose de C. albicans por

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

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    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. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  17. The functions of Mediator in Candida albicans support a role in shaping species-specific gene expression.

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    Nathalie Uwamahoro

    Full Text Available The Mediator complex is an essential co-regulator of RNA polymerase II that is conserved throughout eukaryotes. Here we present the first study of Mediator in the pathogenic fungus Candida albicans. We focused on the Middle domain subunit Med31, the Head domain subunit Med20, and Srb9/Med13 from the Kinase domain. The C. albicans Mediator shares some roles with model yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, such as functions in the response to certain stresses and the role of Med31 in the expression of genes regulated by the activator Ace2. The C. albicans Mediator also has additional roles in the transcription of genes associated with virulence, for example genes related to morphogenesis and gene families enriched in pathogens, such as the ALS adhesins. Consistently, Med31, Med20, and Srb9/Med13 contribute to key virulence attributes of C. albicans, filamentation, and biofilm formation; and ALS1 is a biologically relevant target of Med31 for development of biofilms. Furthermore, Med31 affects virulence of C. albicans in the worm infection model. We present evidence that the roles of Med31 and Srb9/Med13 in the expression of the genes encoding cell wall adhesins are different between S. cerevisiae and C. albicans: they are repressors of the FLO genes in S. cerevisiae and are activators of the ALS genes in C. albicans. This suggests that Mediator subunits regulate adhesion in a distinct manner between these two distantly related fungal species.

  18. Oral Immunization Against Candidiasis Using Lactobacillus casei Displaying Enolase 1 from Candida albicans.

    Science.gov (United States)

    Shibasaki, Seiji; Karasaki, Miki; Tafuku, Senji; Aoki, Wataru; Sewaki, Tomomitsu; Ueda, Mitsuyoshi

    2014-01-01

    Candidiasis is a common fungal infection that is prevalent in immunocompromised individuals. In this study, an oral vaccine against Candida albicans was developed by using the molecular display approach. Enolase 1 protein (Eno1p) of C. albicans was expressed on the Lactobacillus casei cell surface by using poly-gamma-glutamic acid synthetase complex A from Bacillus subtilis as an anchoring protein. The Eno1p-displaying L. casei cells were used to immunize mice, which were later challenged with a lethal dose of C. albicans. The data indicated that the vaccine elicited a strong IgG response and increased the survival rate of the vaccinated mice. Furthermore, L. casei acted as a potent adjuvant and induced high antibody titers that were comparable to those induced by strong adjuvants such as the cholera toxin. Overall, the molecular display method can be used to rapidly develop vaccines that can be conveniently administered and require minimal processing.

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

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

    2013-08-13

    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 formation on silicone elastomers, and pathogenesis in a nematode infection model as well as alters fungal morphology in a mouse mucosal infection assay. We term this compound filastatin based on its strong inhibition of filamentation, and we use chemical genetic experiments to show that it acts downstream of multiple signaling pathways. These studies show that high-throughput functional assays targeting fungal adhesion can provide chemical probes for study of multiple aspects of fungal pathogenesis.

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

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

    2012-12-01

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

  1. Effects of nanosecond pulsed electric fields (nsPEFs) on the human fungal pathogen Candida albicans: an in vitro study

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    Guo, Jinsong; Dang, Jie; Wang, Kaile; Zhang, Jue; Fang, Jing

    2018-05-01

    Candida albicans is the leading human fungal pathogen that causes many life-threatening infections. Notably, the current clinical trial data indicate that Candida species shows the emerging resistance to anti-fungal drugs. The aim of this study was to evaluate the antifungal effects of nanosecond pulsed electric fields (nsPEFs) as a novel drug-free strategy in vitro. In this study, we investigated the inactivation and permeabilization effects of C. albicans under different nsPEFs exposure conditions (100 pulses, 100 ns in duration, intensities of 20, 40 kV cm‑1). Cell death was studied by annexin-V and propidium iodide staining. The changes of intracellular Ca2+ concentration after nsPEFs treatment were observed using Fluo-4 AM. Results show that C. albicans cells and biofilms were both obviously inhibited and destroyed after nsPEFs treatment. Furthermore, C. albicans cells were significantly permeabilized after nsPEFs treatment. Additionally, nsPEFs exposure led to a large amount of DNA and protein leakage. Importantly, nsPEFs induced a field strength-dependent apoptosis in C. albicans cells. Further experiments revealed that Ca2+ involved in nsPEFs induced C. albicans apoptosis. In conclusion, this proof-of-concept study provides a potential alternative drug-free strategy for killing pathogenic Candida species.

  2. Disruption of the ECM33 Gene in Candida albicans Prevents Biofilm Formation, Engineered Human Oral Mucosa Tissue Damage and Gingival Cell Necrosis/Apoptosis

    Directory of Open Access Journals (Sweden)

    Mahmoud Rouabhia

    2012-01-01

    Full Text Available 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.

  3. Relative Abundances of Candida albicans and Candida glabrata in In Vitro Coculture Biofilms Impact Biofilm Structure and Formation.

    Science.gov (United States)

    Olson, Michelle L; Jayaraman, Arul; Kao, Katy C

    2018-04-15

    Candida is a member of the normal human microbiota and often resides on mucosal surfaces such as the oral cavity or the gastrointestinal tract. In addition to their commensality, Candida species can opportunistically become pathogenic if the host microbiota is disrupted or if the host immune system becomes compromised. An important factor for Candida pathogenesis is its ability to form biofilm communities. The two most medically important species- Candida albicans and Candida glabrata -are often coisolated from infection sites, suggesting the importance of Candida coculture biofilms. In this work, we report that biofilm formation of the coculture population depends on the relative ratio of starting cell concentrations of C. albicans and C. glabrata When using a starting ratio of C. albicans to C. glabrata of 1:3, ∼6.5- and ∼2.5-fold increases in biofilm biomass were observed relative to those of a C. albicans monoculture and a C. albicans / C. glabrata ratio of 1:1, respectively. Confocal microscopy analysis revealed the heterogeneity and complex structures composed of long C. albicans hyphae and C. glabrata cell clusters in the coculture biofilms, and reverse transcription-quantitative PCR (qRT-PCR) studies showed increases in the relative expression of the HWP1 and ALS3 adhesion genes in the C. albicans / C. glabrata 1:3 biofilm compared to that in the C. albicans monoculture biofilm. Additionally, only the 1:3 C. albicans / C. glabrata biofilm demonstrated an increased resistance to the antifungal drug caspofungin. Overall, the results suggest that interspecific interactions between these two fungal pathogens increase biofilm formation and virulence-related gene expression in a coculture composition-dependent manner. IMPORTANCE Candida albicans and Candida glabrata are often coisolated during infection, and the occurrence of coisolation increases with increasing inflammation, suggesting possible synergistic interactions between the two Candida species in

  4. Melanocytes and melanin represent a first line of innate immunity against Candida albicans.

    Science.gov (United States)

    Tapia, Cecilia V; Falconer, Maryanne; Tempio, Fabián; Falcón, Felipe; López, Mercedes; Fuentes, Marisol; Alburquenque, Claudio; Amaro, José; Bucarey, Sergio A; Di Nardo, Anna

    2014-07-01

    Melanocytes are dendritic cells located in the skin and mucosae that synthesize melanin. Some infections induce hypo- or hyperpigmentation, which is associated with the activation of Toll-like receptors (TLRs), especially TLR4. Candida albicans is an opportunist pathogen that can switch between blastoconidia and hyphae forms; the latter is associated with invasion. Our objectives in this study were to ascertain whether C. albicans induces pigmentation in melanocytes and whether this process is dependent on TLR activation, as well as relating this with the antifungal activity of melanin as a first line of innate immunity against fungal infections. Normal human melanocytes were stimulated with C. albicans supernatants or with crude extracts of the blastoconidia or hyphae forms, and pigmentation and TLR2/TLR4 expression were measured. Expression of the melanosomal antigens Melan-A and gp100 was examined for any correlation with increased melanin levels or antifungal activity in melanocyte lysates. Melanosomal antigens were induced earlier than cell pigmentation, and hyphae induced stronger melanization than blastoconidia. Notably, when melanocytes were stimulated with crude extracts of C. albicans, the cell surface expression of TLR2/TLR4 began at 48 h post-stimulation and peaked at 72 h. At this time, blastoconidia induced both TLR2 and TLR4 expression, whereas hyphae only induced TLR4 expression. Taken together, these results suggest that melanocytes play a key role in innate immune responses against C. albicans infections by recognizing pathogenic forms of C. albicans via TLR4, resulting in increased melanin content and inhibition of infection. © The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

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    Marilda Aparecida Gonçalves Totti

    2004-09-01

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

  6. 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.

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

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    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.

  8. Identification of salivary components that induce transition of hyphae to yeast in Candida albicans.

    Science.gov (United States)

    Leito, Jelani T D; Ligtenberg, Antoon J M; Nazmi, Kamran; Veerman, Enno C I

    2009-10-01

    Candida albicans, the major human fungal pathogen, undergoes a reversible morphological transition from single yeast cells to pseudohyphae and hyphae filaments. The hyphae form is considered the most invasive form of the fungus. The purpose of this study is to investigate the effect of saliva on hyphae growth of C. albicans. Candida albicans hyphae were inoculated in Roswell Park Memorial Institute medium with whole saliva, parotid saliva or buffer mimicking the saliva ion composition, and cultured for 18 h at 37 degrees C under aerobic conditions with 5% CO(2). Whole saliva and parotid saliva induced transition to yeast growth, whereas the culture with buffer remained in the hyphae form. Parotid saliva was fractionated on a reverse-phase C8 column and each fraction was tested for inducing transition to yeast growth. By immunoblotting, the salivary component in the active fraction was identified as statherin, a phosphoprotein of 43 amino acids that has been implicated in remineralization of the teeth. Synthetically made statherin induced transition of hyphae to yeast. By deletion of five amino acids at the negatively charged N-terminal site (DpSpSEE), yeast-inducing activity and binding to C. albicans were increased. In conclusion, statherin induces transition to yeast of C. albicans hyphae and may thus contribute to the oral defense against candidiasis.

  9. Adhesion of Candida albicans to Vanillin Incorporated Self-Curing Orthodontic PMMA Resin.

    Science.gov (United States)

    Zam, K.; Sawaengkit, P.; Thaweboon, S.; Thaweboon, B.

    2018-02-01

    It has been observed that there is an increase in Candida carriers during the treatment with orthodontic removable appliance. Vanillin is flavouring agent, which is known to have antioxidant and antimicrobial properties. The aim of this study was to evaluate the effect of vanillin incorporated PMMA on adhesion of Candida albicans. A total of 36 orthodontic self-curing PMMA resin samples were fabricated. The samples were divided into 3 groups depending on percentage of vanillin incorporated (0.1%, 0.5% and PMMA without vanillin as control). PMMA samples were coated with saliva. The adhesion assay was performed with C. albicans (ATCC 10231). The adherent yeast cells were stained with crystal violet and counted under microscope by random selection of 3 fields at 10X magnification. The statistical analyses performed by Kruskal Wallis and Mann Whitney non-parametric test. It was found that the PMMA resin samples with vanillin incorporation significantly reduced the adhesion of C. albicans as compared to the control group. This study indicates that vanillin incorporated resin can impede the adhesion of C. albicans to about 45 - 56 %. With further testing and development, vanillin can be employed as an antifungal agent to prevent adhesion of C. albicans to orthodontic self-curing PMMA resin.

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2015-03-01

    Candida albicans is a commensal fungus of the human gastrointestinal tract and a prevalent opportunistic pathogen. To examine diversity within this species, extensive genomic and phenotypic analyses were performed on 21 clinical C. albicans isolates. Genomic variation was evident in the form of polymorphisms, copy number variations, chromosomal inversions, subtelomeric hypervariation, loss of heterozygosity (LOH), and whole or partial chromosome aneuploidies. All 21 strains were diploid, although karyotypic changes were present in eight of the 21 isolates, with multiple strains being trisomic for Chromosome 4 or Chromosome 7. Aneuploid strains exhibited a general fitness defect relative to euploid strains when grown under replete conditions. All strains were also heterozygous, yet multiple, distinct LOH tracts were present in each isolate. Higher overall levels of genome heterozygosity correlated with faster growth rates, consistent with increased overall fitness. Genes with the highest rates of amino acid substitutions included many cell wall proteins, implicating fast evolving changes in cell adhesion and host interactions. One clinical isolate, P94015, presented several striking properties including a novel cellular phenotype, an inability to filament, drug resistance, and decreased virulence. Several of these properties were shown to be due to a homozygous nonsense mutation in the EFG1 gene. Furthermore, loss of EFG1 function resulted in increased fitness of P94015 in a commensal model of infection. Our analysis therefore reveals intra-species genetic and phenotypic differences in C. albicans and delineates a natural mutation that alters the balance between commensalism and pathogenicity. © 2015 Hirakawa et al.; Published by Cold Spring Harbor Laboratory Press.

  12. Comparative Evaluation of Oral Candida albicans Carriage in Children with and without Dental Caries: A Microbiological in vivo Study.

    Science.gov (United States)

    Srivastava, Binita; Bhatia, Hind Pal; Chaudhary, Visuja; Aggarwal, Archana; Kumar Singh, Ashish; Gupta, Nidhi

    2012-05-01

    The aim of this study was to examine the presence of Candida albicans in extensive carious lesions before and after treatment of the carious lesions and to evaluate the carriage of Candida albicans in children with and without caries. The study was conducted on 60 childrens who were divided into two groups: Experimental group (group 1) and controlled group (group 2). Each group was further divided into 3 subgroups according to the dentition as: Group A (Deciduous), group B (Mixed) and group C (Permanent). Swab samples for mycological studies were collected from the dorsum of the tongue, vestibular sulcus and peak of the palatal vault. All samples were cultured directly on SDA plate (Sabouraud's dextrose agar). Number of Candida colonies was determined by counting colony forming unit on SDA plates. Further identification of Candida albicans was done by germ-tube test and corn-meal agar. Overall prevalence of Candida albicans carriage was significantly higher and mean value of Candida albicans CFU (colony forming unit) was remarkably higher in group 1 (experimental group) as compare to group 2 (control group). Significant reduction in the frequency and mean value of Candida albicans CFU/plate was seen in children after treatment of carious lesions. This study supports the active role of Candida species in dental caries. Hence, Candida albicans may play an important role as a risk factor for dental caries. It was also seen that the oral environment stabilization procedures were able to reduce Candida albicans counts. Thus, these procedures can be considered efficient in the reduction of caries risk. How to cite this article: Srivastava B, Bhatia HP, Chaudhary V, Aggarwal A, Singh AK, Gupta N. Comparative Evaluation of Oral Candida albicans Carriage in Children with and without Dental Caries: A Microbiological in vivo Study. Int J Clin Pediatr Dent 2012;5(2):108-112.

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

    International Nuclear Information System (INIS)

    Ismail, A.

    1986-01-01

    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 58 Fe-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

  14. CLONING, EXPRESSION, PURIFICATION AND CRYSTALLIZATION OF A NOVEL GLCNAC METABOLIC PROTEIN, GIG2 (DUF1479 FROM PATHOGENIC FUNGUS CANDIDA ALBICANS

    Directory of Open Access Journals (Sweden)

    Priya Rani1

    2017-06-01

    Full Text Available N-acetylglucosamine (GlcNAc, an alternative sugar, is emerging as an important molecule having a multifarious role in Candida albicans including a major role in signaling. GlcNAc Inducible Gene 2, GIG2 is one of the highly upregulated genes in GlcNAc grown cells in C. albicans. Our earlier studies show the involvement of Gig2 in the formation of N-acetylneuraminic (NANA acid from GlcNAc-6-phosphate through an understudied route. The crystal structure of Gig2 would help us in determining the exact reaction that this enzyme catalyzes. Here the cloning, expression, purification and crystallization of this protein are reported along with preliminary X-ray crystallographic analysis at 2.4Å resolution. The crystal belonged to P21 space group, with unit cell parameters a=59.59, b= 54.43, c= 73.29Å; α = 90°, β = 102.7° and γ = 90°. The structure was solved using PDB ID 2CSG as a template which has only 27% identity. Molecular replacement yielded a solution with LLG score of 87. The structure is currently under further refinement

  15. Identification of salivary components that induce transition of hyphae to yeast in Candida albicans

    NARCIS (Netherlands)

    Leito, J.T.D.; Ligtenberg, A.J.M.; Nazmi, K.; Veerman, E.C.I.

    2009-01-01

    Candida albicans, the major human fungal pathogen, undergoes a reversible morphological transition from single yeast cells to pseudohyphae and hyphae filaments. The hyphae form is considered the most invasive form of the fungus. The purpose of this study is to investigate the effect of saliva on

  16. Central Role for Dermal Fibroblasts in Skin Model Protection against Candida albicans.

    Science.gov (United States)

    Kühbacher, Andreas; Henkel, Helena; Stevens, Philip; Grumaz, Christian; Finkelmeier, Doris; Burger-Kentischer, Anke; Sohn, Kai; Rupp, Steffen

    2017-06-01

    The fungal pathogen Candida albicans colonizes basically all human epithelial surfaces, including the skin. Under certain conditions, such as immunosuppression, invasion of the epithelia occurs. Not much is known about defense mechanisms against C. albicans in subepithelial layers such as the dermis. Using immune cell-supplemented 3D skin models we defined a new role for fibroblasts in the dermis and identified a minimal set of cell types for skin protection against C. albicans invasion. Dual RNA sequencing of individual host cell populations and C. albicans revealed that dermal invasion is directly impeded by dermal fibroblasts. They are able to integrate signals from the pathogen and CD4+ T cells and shift toward an antimicrobial phenotype with broad specificity that is dependent on Toll-like receptor 2 and interleukin 1β. These results highlight a central function of dermal fibroblasts for skin protection, opening new possibilities for treatment of infectious diseases. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

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

    Science.gov (United States)

    Cutler, Jim E; Corti, Miriam; Lambert, Patrick; Ferris, Michael; Xin, Hong

    2011-01-01

    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 efficacy of vaccines

  18. 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

  19. Lemongrass-Incorporated Tissue Conditioner Against Candida albicans Culture

    Science.gov (United States)

    Amornvit, Pokpong; Srithavaj, Theerathavaj

    2014-01-01

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

  20. Photodynamic inactivation of Candida albicans sensitized by tri- and tetra-cationic porphyrin derivatives.

    Science.gov (United States)

    Cormick, M Paula; Alvarez, M Gabriela; Rovera, Marisa; Durantini, Edgardo N

    2009-04-01

    The photodynamic action of 5-(4-trifluorophenyl)-10,15,20-tris(4-trimethylammoniumphenyl)porphyrin iodide (TFAP(3+)) and 5,10,15,20-tetra(4-N,N,N-trimethylammonium phenyl)porphyrin p-tosylate (TMAP(4+)) has been studied in vitro on Candida albicans. The results of these cationic porphyrins were compared with those of 5,10,15,20-tetra(4-sulphonatophenyl)porphyrin (TPPS(4-)), which characterizes an anionic sensitizer. In vitro investigations show that these cationic porphyrins are rapidly bound to C. albicans cells, reaching a value of approximately 1.4 nmol/10(6) cells, when the cellular suspensions were incubated with 5 microM sensitizer for 30 min. In contrast, TPPS(4-) is poorly uptaken by yeast cells. The fluorescence spectra of these sensitizers into the cells confirm this behaviour. The amount of porphyrin binds to cells is dependent on both sensitizer concentrations (1-5 microM) and cells densities (10(6)-10(8) cells/mL). Photosensitized inactivation of C. albicans cellular suspensions increases with sensitizer concentration, causing a approximately 5 log decrease of cell survival, when the cultures are treated with 5 microM of cationic porphyrin and irradiated for 30 min. However, the photocytotoxicity decreases with an increase in the cell density, according to its low binding to cells. Under these conditions, the photodynamic activity of TFAP(3+) is quite similar to that produced by TMAP(4+), whereas no important inactivation effect was found for TPPS(4)(-). The high photodynamic activity of cationic porphyrins was confirmed by growth delay experiments. Thus, C. albicans cell growth was not detected in the presence of 5 microM TFAP(3+). Photodynamic inactivation capacities of these sensitizers were also evaluated on C. albicans cells growing in colonies on agar surfaces. Cationic porphyrins produce a growth delay of C. albicans colonies and viability of cells was not observed after 3 h irradiation, indicating a complete inactivation of yeast cells

  1. Phenotypic Analysis and Virulence of Candida albicans LIG4 Mutants

    Science.gov (United States)

    Andaluz, Encarnación; Calderone, Richard; Reyes, Guadalupe; Larriba, Germán

    2001-01-01

    In previous studies, we reported the isolation and preliminary characterization of a DNA ligase-encoding gene of Candida albicans. This gene (LIG4) is the structural and functional homologue of both yeast and human ligase IV, which is involved in nonhomologous end joining (NHEJ) of DNA double-strand breaks. In the present study, we have shown that there are no other LIG4 homologues in C. albicans. In order to study the function of LIG4 in morphogenesis and virulence, we constructed gene deletions. LIG4 transcript levels were reduced in the heterozygote and were completely absent in null strains. Concomitantly, the heterozygote showed a pronounced defect in myceliation, which was slightly greater in the null strain. This was true with several solid and liquid media, such as Spider medium, medium 199, and 2% glucose–1% yeast extract–2% Bacto Peptone, at several pHs. Reintroduction of the wild-type allele into the null mutant partially restored the ability of cells to form hyphae. In agreement with the positive role of LIG4 in morphogenesis, we detected a significant rise in mRNA levels during the morphological transition. LIG4 is not essential for DNA replication or for the repair of DNA damage induced by ionizing radiation or UV light, indicating that these lesions are repaired primarily by homologous recombination. However, our data show that the NHEJ apparatus of C. albicans may control morphogenesis in this diploid organism. In addition, deletion of one or both copies of LIG4 resulted in attenuation of virulence in a murine model of candidiasis. PMID:11119499

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

    Directory of Open Access Journals (Sweden)

    White Theodore C

    2011-09-01

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

  3. Relationship between Antifungal Activity against Candida albicans and Electron Parameters of Selected N-Heterocyclic Thioamides

    Science.gov (United States)

    Stachowicz, Jadwiga; Krajewska-Kułak, Elżbieta; Łukaszuk, Cecylia; Niewiadomy, A.

    2014-01-01

    Due to the increasing demand for new pharmaceuticals showing biological activity against pathogenic microorganisms, there is increasing search for new compounds with predicted biological activity. Variously substituted thioamide derivatives with 1.3 and 1.2 ring of thiazole and 1,3,4-thiadiazole, as well as pyrazole were assessed for their activity against Candida albicans. Activity of majority of tested thioamides was larger as compared with that of the reference drugs. The electron parameters of obtained N-heterocyclic thioamides were determined and dependencies on their biological activity against Candida albicans were studied. The best electron compliance of produced bindings with the activity against Candida albicans was observed for the derivatives containing 1,3,4-thiadiazole ring. PMID:25284926

  4. 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.

  5. Niche-Specific Requirement for Hyphal Wall protein 1 in Virulence of Candida albicans

    Science.gov (United States)

    Staab, Janet F.; Datta, Kausik; Rhee, Peter

    2013-01-01

    Specialized Candida albicans cell surface proteins called adhesins mediate binding of the fungus to host cells. The mammalian transglutaminase (TG) substrate and adhesin, Hyphal wall protein 1 (Hwp1), is expressed on the hyphal form of C. albicans where it mediates fungal adhesion to epithelial cells. Hwp1 is also required for biofilm formation and mating thus the protein functions in both fungal-host and self-interactions. Hwp1 is required for full virulence of C. albicans in murine models of disseminated candidiasis and of esophageal candidiasis. Previous studies correlated TG activity on the surface of oral epithelial cells, produced by epithelial TG (TG1), with tight binding of C. albicans via Hwp1 to the host cell surfaces. However, the contribution of other Tgs, specifically tissue TG (TG2), to disseminated candidiasis mediated by Hwp1 was not known. A newly created hwp1 null strain in the wild type SC5314 background was as virulent as the parental strain in C57BL/6 mice, and virulence was retained in C57BL/6 mice deleted for Tgm2 (TG2). Further, the hwp1 null strains displayed modestly reduced virulence in BALB/c mice as did strain DD27-U1, an independently created hwp1Δ/Δ in CAI4 corrected for its ura3Δ defect at the URA3 locus. Hwp1 was still needed to produce wild type biofilms, and persist on murine tongues in an oral model of oropharyngeal candidiasis consistent with previous studies by us and others. Finally, lack of Hwp1 affected the translocation of C. albicans from the mouse intestine into the bloodstream of mice. Together, Hwp1 appears to have a minor role in disseminated candidiasis, independent of tissue TG, but a key function in host- and self-association to the surface of oral mucosa. PMID:24260489

  6. Novel Aggregation Properties of Candida albicans Secreted Aspartyl Proteinase Sap6 Mediate Virulence in Oral Candidiasis.

    Science.gov (United States)

    Kumar, Rohitashw; Saraswat, Darpan; Tati, Swetha; Edgerton, Mira

    2015-07-01

    Candida albicans, a commensal fungus of the oral microbiome, causes oral candidiasis in humans with localized or systemic immune deficiencies. Secreted aspartic proteinases (Saps) are a family of 10 related proteases and are virulence factors due to their proteolytic activity, as well as their roles in adherence and colonization of host tissues. We found that mice infected sublingually with C. albicans cells overexpressing Sap6 (SAP6 OE and a Δsap8 strain) had thicker fungal plaques and more severe oral infection, while infection with the Δsap6 strain was attenuated. These hypervirulent strains had highly aggregative colony structure in vitro and higher secreted proteinase activity; however, the levels of proteinase activity of C. albicans Saps did not uniformly match their abilities to damage cultured oral epithelial cells (SCC-15 cells). Hyphal induction in cells overexpressing Sap6 (SAP6 OE and Δsap8 cells) resulted in formation of large cell-cell aggregates. These aggregates could be produced in germinated wild-type cells by addition of native or heat-inactivated Sap6. Sap6 bound only to germinated cells and increased C. albicans adhesion to oral epithelial cells. The adhesion properties of Sap6 were lost upon deletion of its integrin-binding motif (RGD) and could be inhibited by addition of RGD peptide or anti-integrin antibodies. Thus, Sap6 (but not Sap5) has an alternative novel function in cell-cell aggregation, independent of its proteinase activity, to promote infection and virulence in oral candidiasis.

  7. AFM force spectroscopy reveals how subtle structural differences affect the interaction strength between Candida albicans and DC-SIGN

    NARCIS (Netherlands)

    Riet, J. te; Reinieren-Beeren, I.M.J.; Figdor, C.G.; Cambi, A.

    2015-01-01

    The fungus Candida albicans is the most common cause of mycotic infections in immunocompromised hosts. Little is known about the initial interactions between Candida and immune cell receptors, such as the C-type lectin dendritic cell-specific intracellular cell adhesion molecule-3 (ICAM-3)-grabbing

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

    Directory of Open Access Journals (Sweden)

    Sheena D Singh

    2009-07-01

    Full Text Available Candida albicans is the leading fungal pathogen of humans, causing life-threatening disease in immunocompromised individuals. Treatment of candidiasis is hampered by the limited number of antifungal drugs whose efficacy is compromised by host toxicity, fungistatic activity, and the emergence of drug resistance. We previously established that the molecular chaperone Hsp90, which regulates the form and function of diverse client proteins, potentiates resistance to the azoles in C. albicans and in the model yeast Saccharomyces cerevisiae. Genetic studies in S. cerevisiae revealed that Hsp90's role in azole resistance is to enable crucial cellular responses to the membrane stress exerted by azoles via the client protein calcineurin. Here, we demonstrate that Hsp90 governs cellular circuitry required for resistance to the only new class of antifungals to reach the clinic in decades, the echinocandins, which inhibit biosynthesis of a critical component of the fungal cell wall. Pharmacological or genetic impairment of Hsp90 function reduced tolerance of C. albicans laboratory strains and resistance of clinical isolates to the echinocandins and created a fungicidal combination. Compromising calcineurin function phenocopied compromising Hsp90 function. We established that calcineurin is an Hsp90 client protein in C. albicans: reciprocal co-immunoprecipitation validated physical interaction; Hsp90 inhibition blocked calcineurin activation; and calcineurin levels were depleted upon genetic reduction of Hsp90. The downstream effector of calcineurin, Crz1, played a partial role in mediating calcineurin-dependent stress responses activated by echinocandins. Hsp90's role in echinocandin resistance has therapeutic potential given that genetic compromise of C. albicans HSP90 expression enhanced the efficacy of an echinocandin in a murine model of disseminated candidiasis. Our results identify the first Hsp90 client protein in C. albicans, establish an entirely

  9. 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.

  10. 1,4-Naphthoquinone derivatives potently suppress Candida albicans growth, inhibit formation of hyphae and show no toxicity toward zebrafish embryos.

    Science.gov (United States)

    Janeczko, Monika; Kubiński, Konrad; Martyna, Aleksandra; Muzyczka, Angelika; Boguszewska-Czubara, Anna; Czernik, Sławomir; Tokarska-Rodak, Małgorzata; Chwedczuk, Marta; Demchuk, Oleg M; Golczyk, Hieronim; Masłyk, Maciej

    2018-04-01

    In this study, we applied various assays to find new activities of 1,4-naphthoquinone derivatives for potential anti-Candida albicans applications. These assays determined (a) the antimicrobial effect on growth/cell multiplication in fungal cultures, (b) the effect on formation of hyphae and biofilm, (c) the influence on cell membrane integrity, (d) the effect on cell morphology using atomic force microscopy, and (e) toxicity against zebrafish embryos. We have demonstrated the activity of these compounds against different Candida species and clinical isolates of C. albicans. 1,4-Naphthoquinones significantly affected fungal strains at 8-250 mg l -1 of MIC. Interestingly, at concentrations below MICs, the chemicals showed effectiveness in inhibition of hyphal formation and cell aggregation in Candida. Of note, atomic force microscopy (AFM) analysis revealed an influence of the compounds on cell morphological properties. However, at low concentrations (0.8-31.2 mg l -1 ), it did not exert any evident toxic effects on zebrafish embryos. Our research has evidenced the effectiveness of 1,4-naphthoquinones as potential anti-Candida agents.

  11. Lactobacillus rhamnosus inhibits Candida albicans virulence factors in vitro and modulates immune system in Galleria mellonella.

    Science.gov (United States)

    Ribeiro, F C; de Barros, P P; Rossoni, R D; Junqueira, J C; Jorge, A O C

    2017-01-01

    The aim of this study was to evaluate the potential anti-Candida effects of Lactobacillus rhamnosus ATCC 9595 on Candida albicans ATCC 18804 using in vitro and in vivo models. The in vitro analysis evaluated the effects of L. rhamnosus on C. albicans's biofilm formation by CFU count and metabolic activity, filamentation capacity, and adhesion (ALS3 and HWP1) and transcriptional regulatory gene (BCR1 and CPH1) expression. The in vitro results showed that both the L. rhamnosus cells and supernatant reduced C. albicans biofilm formation, filamentation and gene expression. In the in vivo study, the treatment with L. rhamnosus supernatant increased 80% the survival of Galleria mellonella larvae infected with C. albicans. Furthermore, the supernatant of L. rhamnosus recruited haemocytes into the haemolymph (2·1-fold increase). Lactobacillus rhamnosus reduced the biofilm formation and filamentation of C. albicans in vitro by negatively regulating all studied C. albicans genes. Lactobacillus rhamnosus protected G. mellonella against experimental candidiasis in vivo. This study is the first study to report the anti-Candida properties of L. rhamnosus ATCC 9595. The supernatant of this strain has immunomodulatory effects on the G. mellonella model and protects the larvae against pathogens. © 2016 The Society for Applied Microbiology.

  12. Stability of candida albicans over long and short term storage in a ...

    African Journals Online (AJOL)

    BACKGROUND: Candida albicans are widely isolated fungal yeast agents from clinical samples. ... water,Chromagar plate,mineral oil overlay and brain heart infusion broth plus 10% glycerol at -20OC.Recovery rates were determined at six months,12 months and 18 months by sub-culturing onto sabouraud dextrose agar.

  13. Accessibility and contribution to glucan masking of natural and genetically tagged versions of yeast wall protein 1 of Candida albicans.

    Science.gov (United States)

    Granger, Bruce L

    2018-01-01

    Yeast wall protein 1 (Ywp1) is an abundant glycoprotein of the cell wall of the yeast form of Candida albicans, the most prevalent fungal pathogen of humans. Antibodies that bind to the polypeptide backbone of isolated Ywp1 show little binding to intact yeast cells, presumably because the Ywp1 epitopes are masked by the polysaccharides of the mannoproteins that form the outer layer of the cell wall. Rare cells do exhibit much greater anti-Ywp1 binding, however, and one of these was isolated and characterized. No differences were seen in its Ywp1, but it exhibited greater adhesiveness, sensitivity to wall perturbing agents, and exposure of its underlying β-1,3-glucan layer to external antibodies. The molecular basis for this greater epitope accessibility has not been determined, but has facilitated exploration of how these properties change as a function of cell growth and morphology. In addition, previously engineered strains with reduced quantities of Ywp1 in their cell walls were also found to have greater β-1,3-glucan exposure, indicating that Ywp1 itself contributes to the masking of wall epitopes, which may be important for understanding the anti-adhesive effect of Ywp1. Ectopic production of Ywp1 by hyphae, which reduces the adhesivity of these filamentous forms of C. albicans, was similarly found to reduce exposure of the β-1,3-glucan in their walls. To monitor Ywp1 in the cell wall irrespective of its accessibility, green fluorescent protein (Gfp) was genetically inserted into wall-anchored Ywp1 using a bifunctional cassette that also allowed production from a single transfection of a soluble, anchor-free version. The wall-anchored Ywp1-Gfp-Ywp1 accumulated in the wall of the yeast forms but not hyphae, and appeared to have properties similar to native Ywp1, including its adhesion-inhibiting effect. Some pseudohyphal walls also detectably accumulated this probe. Strains of C. albicans with tandem hemagglutinin (HA) epitopes inserted into wall

  14. Accessibility and contribution to glucan masking of natural and genetically tagged versions of yeast wall protein 1 of Candida albicans.

    Directory of Open Access Journals (Sweden)

    Bruce L Granger

    Full Text Available Yeast wall protein 1 (Ywp1 is an abundant glycoprotein of the cell wall of the yeast form of Candida albicans, the most prevalent fungal pathogen of humans. Antibodies that bind to the polypeptide backbone of isolated Ywp1 show little binding to intact yeast cells, presumably because the Ywp1 epitopes are masked by the polysaccharides of the mannoproteins that form the outer layer of the cell wall. Rare cells do exhibit much greater anti-Ywp1 binding, however, and one of these was isolated and characterized. No differences were seen in its Ywp1, but it exhibited greater adhesiveness, sensitivity to wall perturbing agents, and exposure of its underlying β-1,3-glucan layer to external antibodies. The molecular basis for this greater epitope accessibility has not been determined, but has facilitated exploration of how these properties change as a function of cell growth and morphology. In addition, previously engineered strains with reduced quantities of Ywp1 in their cell walls were also found to have greater β-1,3-glucan exposure, indicating that Ywp1 itself contributes to the masking of wall epitopes, which may be important for understanding the anti-adhesive effect of Ywp1. Ectopic production of Ywp1 by hyphae, which reduces the adhesivity of these filamentous forms of C. albicans, was similarly found to reduce exposure of the β-1,3-glucan in their walls. To monitor Ywp1 in the cell wall irrespective of its accessibility, green fluorescent protein (Gfp was genetically inserted into wall-anchored Ywp1 using a bifunctional cassette that also allowed production from a single transfection of a soluble, anchor-free version. The wall-anchored Ywp1-Gfp-Ywp1 accumulated in the wall of the yeast forms but not hyphae, and appeared to have properties similar to native Ywp1, including its adhesion-inhibiting effect. Some pseudohyphal walls also detectably accumulated this probe. Strains of C. albicans with tandem hemagglutinin (HA epitopes inserted into

  15. Humoral response to blastospores and mycelium in mice injected with different doses of Candida albicans.

    Science.gov (United States)

    Mesón, O E; Valdez, J C; de Alderete, N G; Sirena, A; Perdigón, G

    1992-01-01

    An indirect immunofluorescence assay was carry out to determine the IgM and IgG antibody responses to yeast and mycelial forms of Candida albicans in mice injected with a 5 x 5(5) and 5 x 10(7) live cells suspensions. Prior adsorption of the serum samples with heat-killed blastospores enabled us to follow the specific antimycelial response which were detected considerably later than expected. Slow level of antibodies were obtained within an infection of 5 x 10(5) cell for both antibody classes and for yeast and mycelial forms. When a 5 x 10(7) cell dose was used for inoculation, maximum titers of antibodies to blastospores and mycelium in non-adsorbed sera appeared almost simultaneously (days 15 and 13, respectively). When serum samples from mice infected with the same dose were previously adsorbed with blastospores, the antimycelium antibodies for both types of Igs, were detected delayed during the infection course. In this case the higher titer for IgG appeared on day 33 and on day 23 for IgM. We suggest that the high titer obtained with the blastospore forms for the 5 x 10(7) cell dose may be due to a major immunogenicity of this forms, for to induce an immune response in the host, or that the delay in the antimycelium antibodies detection could be due to that a blastospore form is the predominant in the infection early stages. Implications of this fact for pathogenesis are discussed.

  16. Candida albicans, Staphylococcus aureus and Streptococcus mutans colonization in patients wearing dental prosthesis.

    Science.gov (United States)

    Baena-Monroy, Tania; Moreno-Maldonado, Víctor; Franco-Martínez, Fernando; Aldape-Barrios, Beatriz; Quindós, Guillermo; Sánchez-Vargas, Luis Octavio

    2005-04-01

    Denture stomatitis is associated to Candida albicans, different bacteria and other co-factors such as an acid pH, a carbohydrate ingestion increase, different systemic illnesses and pharmacological treatments. The aim of this study was to determine Candida albicans, Staphylococcus aureus and Streptococcus mutans prevalence in the mucous membrane and prosthesis of patients with and without atrophic denture stomatitis and its relationship with other potential clinical co-factors. Saliva was collected from 105 patients (62 female and 43 male) wearing dental prosthesis in order to measure their pH. Oral samples of the mucous membrane and the internal surface of dental prosthesis were taken with sterile cotton to proceed with the microbiological study. The identification of the isolated microorganisms was performed using conventional microbiological methods. Diabetes and Hypertension were the most frequent systemic illnesses. High carbohydrate ingestion was observed in numerous patients. Atrophic denture stomatitis was reported in 50 patients and the pH average in saliva was of 5.2. The presence of C albicans, S. aureus and S. mutans in the mucous membrane and prosthesis was of 51.4%, 52.4% and 67.6%, respectively. C. albicans was isolated in 66.7% from the prosthesis, whereas S. aureus and S. mutans were isolated in 49.5% of those same prosthesis. C. albicans was isolated in 86% of the patients with atrophic denture stomatitis and S. aureus was isolated in a similar percentage (84% of patients). The isolation of S. mutans was less frequent, and it was observed in 16% of the oral samples of these patients. C. albicans, S. aureus and S. mutans frequently colonize the oral mucous of patients wearing dental prosthesis. This illness-bearing condition is more frequent in patients with denture stomatitis, even though dental prosthesis colonization is lower than in the oral mucous.

  17. Risk factors for fatal candidemia caused by Candida albicans and non-albicans Candida species

    Directory of Open Access Journals (Sweden)

    Tang Ran-Bin

    2005-04-01

    Full Text Available Abstract Background Invasive fungal infections, such as candidemia, caused by Candida species have been increasing. Candidemia is not only associated with a high mortality (30% to 40% but also extends the length of hospital stay and increases the costs of medical care. Sepsis caused by Candida species is clinically indistinguishable from bacterial infections. Although, the clinical presentations of the patients with candidemia caused by Candida albicans and non-albicans Candida species (NAC are indistinguishable, the susceptibilities to antifungal agents of these species are different. In this study, we attempted to identify the risk factors for candidemia caused by C. albicans and NAC in the hope that this may guide initial empiric therapy. Methods A retrospective chart review was conducted during 1996 to 1999 at the Veterans General Hospital-Taipei. Results There were 130 fatal cases of candidemia, including 68 patients with C. albicans and 62 with NAC. Candidemia was the most likely cause of death in 55 of the 130 patients (42.3 %. There was no significant difference in the distribution of Candida species between those died of candidemia and those died of underlying conditions. Patients who had one of the following conditions were more likely to have C. albicans, age ≧ 65 years, immunosuppression accounted to prior use of steroids, leukocytosis, in the intensive care unit (ICU, and intravascular and urinary catheters. Patients who had undergone cancer chemotherapy often appeared less critically ill and were more likely to have NAC. Conclusion Clinical and epidemiological differences in the risk factors between candidemia caused by C. albicans and NAC may provide helpful clues to initiate empiric therapy for patients infected with C. albicans versus NAC.

  18. Risk factors for fatal candidemia caused by Candida albicans and non-albicans Candida species

    Science.gov (United States)

    Cheng, Ming-Fang; Yang, Yun-Liang; Yao, Tzy-Jyun; Lin, Chin-Yu; Liu, Jih-Shin; Tang, Ran-Bin; Yu, Kwok-Woon; Fan, Yu-Hua; Hsieh, Kai-Sheng; Ho, Monto; Lo, Hsiu-Jung

    2005-01-01

    Background Invasive fungal infections, such as candidemia, caused by Candida species have been increasing. Candidemia is not only associated with a high mortality (30% to 40%) but also extends the length of hospital stay and increases the costs of medical care. Sepsis caused by Candida species is clinically indistinguishable from bacterial infections. Although, the clinical presentations of the patients with candidemia caused by Candida albicans and non-albicans Candida species (NAC) are indistinguishable, the susceptibilities to antifungal agents of these species are different. In this study, we attempted to identify the risk factors for candidemia caused by C. albicans and NAC in the hope that this may guide initial empiric therapy. Methods A retrospective chart review was conducted during 1996 to 1999 at the Veterans General Hospital-Taipei. Results There were 130 fatal cases of candidemia, including 68 patients with C. albicans and 62 with NAC. Candidemia was the most likely cause of death in 55 of the 130 patients (42.3 %). There was no significant difference in the distribution of Candida species between those died of candidemia and those died of underlying conditions. Patients who had one of the following conditions were more likely to have C. albicans, age ≧ 65 years, immunosuppression accounted to prior use of steroids, leukocytosis, in the intensive care unit (ICU), and intravascular and urinary catheters. Patients who had undergone cancer chemotherapy often appeared less critically ill and were more likely to have NAC. Conclusion Clinical and epidemiological differences in the risk factors between candidemia caused by C. albicans and NAC may provide helpful clues to initiate empiric therapy for patients infected with C. albicans versus NAC. PMID:15813977

  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. 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.

  1. Functional Genomic Screening Reveals Core Modulators of Echinocandin Stress Responses in Candida albicans

    Directory of Open Access Journals (Sweden)

    Tavia Caplan

    2018-05-01

    Full Text Available Summary: Candida albicans is a leading cause of death due to fungal infection. Treatment of systemic candidiasis often relies on echinocandins, which disrupt cell wall synthesis. Resistance is readily acquired via mutations in the drug target gene, FKS1. Both basal tolerance and resistance to echinocandins require cellular stress responses. We performed a systematic analysis of 3,030 C. albicans mutants to define circuitry governing cellular responses to echinocandins. We identified 16 genes for which deletion or transcriptional repression enhanced echinocandin susceptibility, including components of the Pkc1-MAPK signaling cascade. We discovered that the molecular chaperone Hsp90 is required for the stability of Pkc1 and Bck1, establishing key mechanisms through which Hsp90 mediates echinocandin resistance. We also discovered that perturbation of the CCT chaperonin complex causes enhanced echinocandin sensitivity, altered cell wall architecture, and aberrant septin localization. Thus, we provide insights into the mechanisms by which cellular chaperones enable crucial responses to echinocandin-induced stress. : Caplan et al. screen 3,030 Candida albicans mutants to define circuitry governing cellular responses to echinocandins, the first-line therapy for systemic candidiasis. They reveal that the molecular chaperone Hsp90 is required for stability of Pkc1 and Bck1 and that the CCT chaperonin complex is a key modulator of echinocandin susceptibility. Keywords: fungal pathogen, Candida albicans, echinocandins, Hsp90, Pkc1, CCT complex, client protein, stress response, functional genomic screen, drug resistance

  2. Use of multilocus sequence typing for the investigation of colonisation by Candida albicans in intensive care unit patients.

    Science.gov (United States)

    Cliff, P R; Sandoe, J A T; Heritage, J; Barton, R C

    2008-05-01

    A prospective study was performed to determine the prevalence of candidal colonisation on the general intensive care unit at a large teaching hospital. Colonisation with Candida spp. was found to be common, occurring in 79% of patients on the unit. C. albicans was the commonest species, colonising 64% of patients, followed by C. glabrata (18%) and C. parapsilosis (14%). Most of the members of staff tested carried Candida spp. at some point, although carriage appeared to be transient. C. parapsilosis was the most commonly isolated species from staff hands, whereas C. albicans was the most commonly isolated species from the mouth. The molecular epidemiology of C. albicans was investigated using Ca3 typing and multilocus sequence typing (MLST). MLST proved to be a reproducible typing method and a useful tool for the investigation of the molecular epidemiology of C. albicans. The results of the molecular typing provided evidence for the presence of an endemic strain on the unit, which was isolated repeatedly from patients and staff. This finding suggests horizontal transmission of C. albicans on the unit though it may also reflect the relative frequency of C. albicans strain types colonising patients on admission. This study has important implications for the epidemiology of systemic candidal infections.

  3. Effect of whey goat milk kefir on hydrophobicity of E. coli O157:H7, S. typhi bacteria and C. albicans

    Directory of Open Access Journals (Sweden)

    Dedi Fardiaz

    2012-03-01

    Full Text Available The hydrophobicity of bacteria. was determined using BATH (Bacteria adhesion to hydrocarbon test. All bacteria showed that 0,9 ml n-octane exposure gave a positive response and indicating that E. coli O157:H7 was categorized as moderate hydrophobic bacteria,  while S.  typhi  and C. albicans were catagorized as  highly hydrophobic bacteria. Goat Milk Kefir increased hydrophobicity of E.  coli O157:H7 by 24.40, however, decreased hydrophobicity of S. typhi by 47.56  and C. albicans by 70.14 percent, respectively. This finding showed that one of the inhibition mechanism may be caused by  an interaction  of  organic acid and peptide  compounds with cell membrane, in which hydrophobic sites of component  modified the hydrophobicity of the bacteria cell surface. The hydrophobicity modification in bacterial  cell wall might result inhibition of adhetion bacteria at cell host. Key words : Enterophatogenic bacteria, hidrophobisitas bacteria

  4. Purification and germination of Candida albicans and Candida dubliniensis chlamydospores cultured in liquid media

    OpenAIRE

    Citiulo, Francesco; Moran, Gary; COLEMAN, DAVID; SULLIVAN, DEREK

    2009-01-01

    PUBLISHED Candida albicans and Candida dubliniensis are the only Candida species 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...

  5. The use of flow cytometry to monitor chitin synthesis in regenerating protoplasts of Candida albicans.

    Science.gov (United States)

    Hector, R F; Braun, P C; Hart, J T; Kamarck, M E

    1990-01-01

    Flow cytometry was used to monitor chitin synthesis in regenerating protoplasts of the yeast Candida albicans. Comparisons of cells stained with Calcofluor White, a fluorochrome with known affinity for chitin, and cells incubated in the presence of N-[3H]-acetylglucosamine, the precursor substrate for chitin, showed a linear relationship between fluorescence and incorporation of label over time. Changes in both the fluorescence and light scatter of regenerating protoplasts treated with inhibitors of fungal chitin synthase were also quantitated by flow cytometry.

  6. Determining the bacterial cell biology of Planctomycetes.

    Science.gov (United States)

    Boedeker, Christian; Schüler, Margarete; Reintjes, Greta; Jeske, Olga; van Teeseling, Muriel C F; Jogler, Mareike; Rast, Patrick; Borchert, Daniela; Devos, Damien P; Kucklick, Martin; Schaffer, Miroslava; Kolter, Roberto; van Niftrik, Laura; Engelmann, Susanne; Amann, Rudolf; Rohde, Manfred; Engelhardt, Harald; Jogler, Christian

    2017-04-10

    Bacteria of the phylum Planctomycetes have been previously reported to possess several features that are typical of eukaryotes, such as cytosolic compartmentalization and endocytosis-like macromolecule uptake. However, recent evidence points towards a Gram-negative cell plan for Planctomycetes, although in-depth experimental analysis has been hampered by insufficient genetic tools. Here we develop methods for expression of fluorescent proteins and for gene deletion in a model planctomycete, Planctopirus limnophila, to analyse its cell organization in detail. Super-resolution light microscopy of mutants, cryo-electron tomography, bioinformatic predictions and proteomic analyses support an altered Gram-negative cell plan for Planctomycetes, including a defined outer membrane, a periplasmic space that can be greatly enlarged and convoluted, and an energized cytoplasmic membrane. These conclusions are further supported by experiments performed with two other Planctomycetes, Gemmata obscuriglobus and Rhodopirellula baltica. We also provide experimental evidence that is inconsistent with endocytosis-like macromolecule uptake; instead, extracellular macromolecules can be taken up and accumulate in the periplasmic space through unclear mechanisms.

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

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    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.

  8. 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.

  9. Cell fate determination in the Caenorhabditis elegans epidermal lineages

    NARCIS (Netherlands)

    Soete, G.A.J.

    2007-01-01

    The starting point for this work was to use the hypodermal seam of C. elegans as a model system to study cell fate determination. Even though the seam is a relatively simple developmental system, the mechanisms that control cell fate determination in the seam lineages are connected in a highly

  10. 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.

  11. Toxicity of nalidixic acid on candida albicans, Saccharomyces cerevisiae, and Kluyveromyces lactis.

    Science.gov (United States)

    Sobieski, R J; Brewer, A R

    1976-03-01

    The antibacterial drug nalidixic acid (Nal) can suppress the growth of Candida albicans at levels of the drug normally found in urine. Growth suppression increases as drug levels are increased, and Nal also causes a similar proportional inhibition of the synthesis of all cellular macromolecules. However, growth temperature (25 versus 37 C) and the divalent cations Mg(2+) and Mn(2+) can increase C. albicans resistance to Nal. Also, nitrogen depletion of Candida shows that Nal-treated and untreated cells exhibit no difference in leucine uptake during readaptation to nitrogen. In Nal-treated, nitrogen-starved cells, ribonucleic acid and deoxyribonucleic acid (DNA) biosynthesis are less affected than in unstarved Nal-treated cells, but of the two nucleic acids DNA synthesis is the most affected. Nal-resistant strains of C. albicans exhibit a slight toxicity for macromolecular synthesis. Nal treatment of a synchronized population of Saccharomyces cerevisiae results in an increase in the culture mean doubling time of, at most, 20%, but Nal causes the loss of synchronous cell division. With a synchronized population of Kluyveromyces lactis, Nal causes an increase in the mean doubling time of upwards of 300%, with synchrony of cell division being maintained. It is known that S. cerevisiae asynchronously synthesizes mitochondrial DNA during the cell cycle, whereas with K. lactis it is synchronous. Thus, with C. albicans Nal toxicity is dependent both on the dose and the physiological state of the cell. Furthermore, Nal inhibits growth of yeast with synchronous mitochondrial DNA synthesis more adversely than yeast with asynchronous mitochondrial DNA synthesis.

  12. The Antifungal Inhibitory Concentration Effectiveness Test From Ethanol Seed Arabica Coffee (Coffea arabica) Extract Against The Growth Of Candida albicans Patient Isolate With In Vitro Method

    Science.gov (United States)

    Satria Rakatama, Adam; Pramono, Andri; Yulianti, Retno

    2018-03-01

    Candida albicans are the most frequent cause of Vulvovaginalis Candidiasis infection. Its treatment using antifungal drugs, are oftenly caused side effects. The reduction of C.albicans growth and the reduction of antifungal drugs side effect, were our main purposed. Our study objective is determine the effectiveness of inhibitory power of arabica coffee seed ethanol extract on the growth of C.albicans patient isolates. The type of this research is experimental research. Kirby-bauer method with the Saboraud Dextrose Agar (SDA) media was used in this experiment. Inhibitory zone was observed around the disc, to determine the inhibitory power. The results showed that the inhibitory zone was formed on arabica coffee seed ethanol extract on 10%, 20%, 40%, and 80% concentration. Kruskal-Wallis test results (pthe concentration groups tested against the treatment group. The inhibitory zone was formed because of biochemical compound in arabica coffee seed such as caffeine, phenol, alkaloids, flavonoids, and saponins. Inhibitory zone in C.albicans patient isolates were smaller compared with C.albicans ATCC 90028 as gold standard. This showed that the virulence of C.albicans from patients isolates were higher. We concluded that arabica coffee seed ethanol extract could inhibiting the growth of C.albicans patient isolates. Optimization of coffee seed ethanol extract to obtain maximum active ingredients still needs to be done. This knowledge is expected to be used for the beginning manufacturer antifungal drug from natural product.

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

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    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.

  14. Candida albicans response to spaceflight (NASA STS-115)

    Data.gov (United States)

    National Aeronautics and Space Administration — This study presents the first global transcriptional profiling and phenotypic characterization of the major human opportunistic fungal pathogen Candida albicans...

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

    International Nuclear Information System (INIS)

    Guo, Qing-Lian; Zhang, Juan; Xu, Zi-Qiang; Li, Ran; Jiang, Feng-Lei; Xiao, Qi; Liu, Yi

    2012-01-01

    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 (IC 50 ) 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.

  16. 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.

  17. A relay network of extracellular heme-binding proteins drives C. albicans iron acquisition from hemoglobin.

    Science.gov (United States)

    Kuznets, Galit; Vigonsky, Elena; Weissman, Ziva; Lalli, Daniela; Gildor, Tsvia; Kauffman, Sarah J; Turano, Paola; Becker, Jeffrey; Lewinson, Oded; Kornitzer, Daniel

    2014-10-01

    Iron scavenging constitutes a crucial challenge for survival of pathogenic microorganisms in the iron-poor host environment. Candida albicans, like many microbial pathogens, is able to utilize iron from hemoglobin, the largest iron pool in the host's body. Rbt5 is an extracellular glycosylphosphatidylinositol (GPI)-anchored heme-binding protein of the CFEM family that facilitates heme-iron uptake by an unknown mechanism. Here, we characterize an additional C. albicans CFEM protein gene, PGA7, deletion of which elicits a more severe heme-iron utilization phenotype than deletion of RBT5. The virulence of the pga7-/- mutant is reduced in a mouse model of systemic infection, consistent with a requirement for heme-iron utilization for C. albicans pathogenicity. The Pga7 and Rbt5 proteins exhibit distinct cell wall attachment, and discrete localization within the cell envelope, with Rbt5 being more exposed than Pga7. Both proteins are shown here to efficiently extract heme from hemoglobin. Surprisingly, while Pga7 has a higher affinity for heme in vitro, we find that heme transfer can occur bi-directionally between Pga7 and Rbt5, supporting a model in which they cooperate in a heme-acquisition relay. Together, our data delineate the roles of Pga7 and Rbt5 in a cell surface protein network that transfers heme from extracellular hemoglobin to the endocytic pathway, and provide a paradigm for how receptors embedded in the cell wall matrix can mediate nutrient uptake across the fungal cell envelope.

  18. Antifungal activity of caspofungin in experimental infective endocarditis caused by Candida albicans.

    Science.gov (United States)

    Victorio, Gerardo Becerra; Bourdon, Lorena Michele Brennan; Benavides, Leonel García; Huerta-Olvera, Selene G; Plascencia, Arturo; Villanueva, José; Martinez-Lopez, Erika; Hernández-Cañaveral, Iván Isidro

    2017-05-01

    Infective endocarditis is a disease characterised by heart valve lesions, which exhibit extracellular matrix proteins that act as a physical barrier to prevent the passage of antimicrobial agents. The genus Candida has acquired clinical importance given that it is increasingly being isolated from cases of nosocomial infections. To evaluate the activity of caspofungin compared to that of liposomal amphotericin B against Candida albicans in experimental infective endocarditis. Wistar rats underwent surgical intervention and infection with strains of C. albicans to develop infective endocarditis. Three groups were formed: the first group was treated with caspofungin, the second with liposomal amphotericin B, and the third received a placebo. In vitro sensitivity was first determined to further evaluate the effect of these treatments on a rat experimental model of endocarditis by semiquantitative culture of fibrinous vegetations and histological analysis. Our semiquantitative culture of growing vegetation showed massive C. albicans colonisation in rats without treatment, whereas rats treated with caspofungin showed significantly reduced colonisation, which was similar to the results obtained with liposomal amphotericin B. The antifungal activity of caspofungin is similar to that of liposomal amphotericin B in an experimental model of infective endocarditis caused by C. albicans.

  19. UJI AKTIVITAS ANTIJAMUR INFUSA UMBI BAWANG PUTIH (Allium sativum L. TERHADAP Candida albicans SERTA PROFIL KROMATOGRAFINYA

    Directory of Open Access Journals (Sweden)

    Khusnul Diana

    2016-03-01

    Full Text Available As traditional medicine, bawang putih or garlic ( Allium sativum L. can cure as antibacterial and antifungal beside on can restorative as antihypertension, antacid, carminativa (in the dyspepsia, expectorancia and anticolesterol. This research was conducted in order to know the antifungal activity of infusion of Allium sativum against Candida albicans and to identify chemical component’s of this infusion. The antifungal activity was done by liquid dilution method. The MIC (Minimal Inhibitory Concentration and MFC (Minimal Fungicidal Concentration value were used as parameter to determine the antifungal activity. Concentration used in this reseach were 17,5%; 16,25%; 15%; 13,75% ; 12,5% dan 11,25% v/v for Candida albicans. The activity was done by incubating the infusion with fungal in CYG DS media of 37ºC for 18-24 hours. Identification of chemical component was carried out by paper chromatography and thin layer chromatography. The result showed that the MIC (Minimum Inhibitor Concentration for Candida albicans could not be observed because the mixture was turbid. The MFC (Minimum Fungicidal Concentration for Candida albicans was 15% v/v. The tube test and chromatogram showed that the infusion of Allium sativum contained flavonoid, and saponin.

  20. Effect of a Lactobacillus Salivarius Probiotic on a Double-Species Streptococcus Mutans and Candida Albicans Caries Biofilm.

    Science.gov (United States)

    Krzyściak, Wirginia; Kościelniak, Dorota; Papież, Monika; Vyhouskaya, Palina; Zagórska-Świeży, Katarzyna; Kołodziej, Iwona; Bystrowska, Beata; Jurczak, Anna

    2017-11-14

    The aim of the study was to evaluate the anti-cariogenic effects of Lactobacillus salivarius by reducing pathogenic species and biofilm mass in a double-species biofilm model. Coexistence of S. mutans with C. albicans can cause dental caries progression or recurrence of the disease in the future. Fifty-nine children with diagnosed early childhood caries (ECC) were recruited onto the study. The condition of the children's dentition was defined according to the World Health Organization guidelines. The participants were divided into children with initial enamel demineralization and children showing dentin damage. The study was performed on the S. mutans and C. albicans clinical strains, isolated from dental plaque of patients with ECC. The effect of a probiotic containing Lactobacillus salivarius on the ability of S. mutans and C. albicans to produce a double-species biofilm was investigated in an in vitro model. The biomass of the formed/non-degraded biofilm was analyzed on the basis of its crystal violet staining. The number of colonies of S. mutans and C. albicans (CFU/mL, colony forming units/mL) forming the biofilm was determined. Microorganism morphology in the biofilm was evaluated using a scanning electron microscope (SEM). In vitro analysis demonstrated that the presence of S. mutans increased the number of C. albicans colonies (CFU/mL); the double-species biofilm mass and hyphal forms produced in it by the yeast. L. salivarius inhibited the cariogenic biofilm formation of C. albicans and S. mutans . Under the influence of the probiotic; the biofilm mass and the number of S. mutans ; C. albicans and S. mutans with C. albicans colonies in the biofilm was decreased. Moreover; it can be noted that after the addition of the probiotic; fungi did not form hyphae or germ tubes of pathogenic potential. These results suggest that L. salivarius can secrete intermediates capable of inhibiting the formation of cariogenic S. mutans and C. albicans biofilm; and may

  1. Effect of a Lactobacillus Salivarius Probiotic on a Double-Species Streptococcus Mutans and Candida Albicans Caries Biofilm

    Directory of Open Access Journals (Sweden)

    Wirginia Krzyściak

    2017-11-01

    Full Text Available The aim of the study was to evaluate the anti-cariogenic effects of Lactobacillus salivarius by reducing pathogenic species and biofilm mass in a double-species biofilm model. Coexistence of S. mutans with C. albicans can cause dental caries progression or recurrence of the disease in the future. Fifty-nine children with diagnosed early childhood caries (ECC were recruited onto the study. The condition of the children’s dentition was defined according to the World Health Organization guidelines. The participants were divided into children with initial enamel demineralization and children showing dentin damage. The study was performed on the S. mutans and C. albicans clinical strains, isolated from dental plaque of patients with ECC. The effect of a probiotic containing Lactobacillus salivarius on the ability of S. mutans and C. albicans to produce a double-species biofilm was investigated in an in vitro model. The biomass of the formed/non-degraded biofilm was analyzed on the basis of its crystal violet staining. The number of colonies of S. mutans and C. albicans (CFU/mL, colony forming units/mL forming the biofilm was determined. Microorganism morphology in the biofilm was evaluated using a scanning electron microscope (SEM. In vitro analysis demonstrated that the presence of S. mutans increased the number of C. albicans colonies (CFU/mL; the double-species biofilm mass and hyphal forms produced in it by the yeast. L. salivarius inhibited the cariogenic biofilm formation of C. albicans and S. mutans. Under the influence of the probiotic; the biofilm mass and the number of S. mutans; C. albicans and S. mutans with C. albicans colonies in the biofilm was decreased. Moreover; it can be noted that after the addition of the probiotic; fungi did not form hyphae or germ tubes of pathogenic potential. These results suggest that L. salivarius can secrete intermediates capable of inhibiting the formation of cariogenic S. mutans and C. albicans biofilm

  2. Effects of trimethylsilane plasma coating on the hydrophobicity of denture base resin and adhesion of Candida albicans on resin surfaces.

    Science.gov (United States)

    Liu, Tianshuang; Xu, Changqi; Hong, Liang; Garcia-Godoy, Franklin; Hottel, Timothy; Babu, Jegdish; Yu, Qingsong

    2017-12-01

    Candida-associated denture stomatitis is the most common oral mucosal lesion among denture wearers. Trimethylsilane (TMS) plasma coating may inhibit the growth of Candida albicans on denture surfaces. The purpose of this in vitro study was to investigate whether TMS plasma coatings can effectively reduce C albicans adhesion on denture base acrylic resin surfaces. Sixty denture base acrylic resin disks with smooth and rough surfaces were prepared and were either left untreated (control group) or coated with TMS monomer (experimental group) by using plasma. Contact angles were measured immediately after TMS plasma coating. The morphology of C albicans adhesion was observed with scanning electron microscopy (SEM). Energy-dispersive spectroscopy (EDS) was used to characterize the elemental composition of the specimen surface. An adhesion test was performed by incubating the resin disk specimens in C albicans suspensions (1×10 7 cells/mL) at 37°C for 24 hours and further measuring the optical density of the C albicans by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay test. One-way ANOVA and 2-way ANOVA were followed by a post hoc test analysis (α=.05). The group with TMS coating exhibited a more hydrophobic surface than the control group. EDS analysis revealed successful TMS plasma coating. The difference in the mean contact angles between the uncoated group and the TMS-coated group was statistically significant (Pcoating than on the surfaces of the experimental group. In the adhesion test, the amount of C albicans adhering to the surface of denture base resin with the TMS coating was significantly less than that on the surfaces without TMS coating (Pcoating significantly reduced the adhesion of C albicans to the denture base resin and may reduce denture stomatitis. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  3. 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.

  4. Bactericidal activity of culture fluid components of Lactobacillus fermentum strain 90 TS-4 (21) clone 3, and their capacity to modulate adhesion of Candida albicans yeast-like fungi to vaginal epithelial cells.

    Science.gov (United States)

    Anokhina, I V; Kravtsov, E G; Protsenko, A V; Yashina, N V; Yermolaev, A V; Chesnokova, V L; Dalin, M V

    2007-03-01

    Antagonistic activities of L. fermentum strain 90 TS-4 (21), L. casei ATCC 27216, and L. acidophilus ATCC 4356 and bactericidal activity of lactobacillus culture fluid towards E. coli strain K12, S. aureus, and S. epidermidis test cultures were studied. The bactericidal effect of L. fermentum strain 90 TS-4 (21) clone 3 culture fluid preparation (pH 6.0) on the test cultures was dose-dependent. Adhesion of C. albicans yeast-like fungi to vaginal epitheliocytes was more pronounced for strains isolated from women with asymptomatic infection than for strains isolated from women with manifest forms. L. fermentum strain 90 TS-4 (21) clone 3 culture fluid preparation modulated adhesion of yeast-like fungi only if the fungal strain was initially highly adherent.

  5. Biosurfactants prevent in vitro Candida albicans biofilm formation on resins and silicon materials for prosthetic devices.

    Science.gov (United States)

    Cochis, Andrea; Fracchia, Letizia; Martinotti, Maria Giovanna; Rimondini, Lia

    2012-06-01

    The aim of this study was to evaluate in vitro the preventive antiadhesion activity of biosurfactants against Candida albicans biofilm. Disks of silicon and acrylic resin for denture prostheses were precoated with increasing concentrations of biosurfactants obtained from endophyte biofilms selected from Robinia pseudoacacia and from Nerium oleander, and afterward infected with C. albicans cells. The number of biofilm cells were detected by colony-forming unit (CFU) counting, cell viability was established by the 2,3-bis(2-methoxy-4-nitro-5-sulphophenyl)-5-[(phenyl amino)carbonyl]-2H-tetrazolium hydroxide (XTT) assay, and biosurfactant cytotoxicity was evaluated by the [3-(4,5-dimethyliazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium] (MTT) assay. Chlorhexidine was used as control. Precoating with biosurfactants caused a greater reduction (P biosurfactants was observed at low concentrations (78.12 μg/mL and 156.12 μg/mL) which were noncytotoxic. This study demonstrated the preventive antiadhesion activity of biosurfactants against C. albicans biofilm. These agents are amphiphilic, interfere with microbial adhesion, and demonstrate cycompatibility with epithelial cells and fibroblasts. Copyright © 2012 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    Chowdhury, Tahmeena; Köhler, Julia R

    2015-10-01

    TOR and PKA signaling pathways control eukaryotic cell growth and proliferation. TOR activity in model fungi, such as Saccharomyces cerevisiae, responds principally to nutrients, e.g., nitrogen and phosphate sources, which are incorporated into the growing cell mass; PKA signaling responds to the availability of the cells' major energy source, glucose. In the fungal commensal and pathogen, Candida albicans, little is known of how these pathways interact. Here, the signal from phosphorylated ribosomal protein S6 (P-S6) was defined as a surrogate marker for TOR-dependent anabolic activity in C. albicans. Nutritional, pharmacologic and genetic modulation of TOR activity elicited corresponding changes in P-S6 levels. The P-S6 signal corresponded to translational activity of a GFP reporter protein. Contributions of four PKA pathway components to anabolic activation were then examined. In high glucose concentrations, only Tpk2 was required to upregulate P-S6 to physiologic levels, whereas all four tested components were required to downregulate P-S6 in low glucose. TOR was epistatic to PKA components with respect to P-S6. In many host niches inhabited by C. albicans, glucose is scarce, with protein being available as a nitrogen source. We speculate that PKA may modulate TOR-dependent cell growth to a rate sustainable by available energy sources, when monomers of anabolic processes, such as amino acids, are abundant. © 2015 John Wiley & Sons Ltd.

  7. Otite externe maligne à Candida Albicans

    Science.gov (United States)

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

    2016-01-01

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

  8. Candida albicans osteomyelitis of the cervical spine

    International Nuclear Information System (INIS)

    Cha, Jang-Gyu; Hong, Hyun-Sook; Koh, Yoon-Woo; Kim, Hee-Kyung; Park, Jung-Mi

    2008-01-01

    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.)

  9. Acid production by oral strains of Candida albicans and Lactobacilli

    NARCIS (Netherlands)

    Klinke, T.; Kneist, S.; de Soet, J.J.; Kuhlisch, E.; Mauersberger, S.; Forster, A.; Klimm, W.

    2009-01-01

    Both Candida albicans and lactobacilli are common colonizers of carious lesions in children and adolescents. The purpose of this study is to compare the velocity of acid production between C. albicans and several Lactobacillus species at different pH levels and concentrations of glucose. Washed,

  10. Cell fate determination in zebrafish embryonic and adult muscle development

    NARCIS (Netherlands)

    Tee, J.M.

    2010-01-01

    We are interested in how the genetic basis of muscle precursor cells determines the outcome of the muscle cell fate, and thus leading to disruption in muscle formation and maintenance. We utilized the zebrafish carrying mutations in both Axin1 and Apc1, resulting in overactivation of the

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  13. 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.

  14. Nanofiber density determines endothelial cell behavior on hydrogel matrix

    International Nuclear Information System (INIS)

    Berti, Fernanda V.; Rambo, Carlos R.; Dias, Paulo F.; Porto, Luismar M.

    2013-01-01

    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

  15. A phenotypic profile of the Candida albicans regulatory network.

    Directory of Open Access Journals (Sweden)

    Oliver R Homann

    2009-12-01

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

  16. A phenotypic profile of the Candida albicans regulatory network.

    Science.gov (United States)

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

    2009-12-01

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

  17. Molecular cloning of a Candida albicans gene (SSB1) coding for a protein related to the Hsp70 family.

    Science.gov (United States)

    Maneu, V; Cervera, A M; Martinez, J P; Gozalbo, D

    1997-06-15

    We have cloned and sequenced a Candida albicans gene (SSB1) encoding a potential member of the heat-shock protein seventy (hsp70) family. The protein encoded by this gene contains 613 amino acids and shows a high degree (85%) of sequence identity to the ssb subfamily (ssb1 and ssb2) of the Saccharomyces cerevisiae hsp70 family. The transcribed mRNA (2.1 kb) is present in similar amounts both in yeast and germ tube cells of C. albicans.

  18. Farnesol signalling in Candida albicans - more than just communication.

    Science.gov (United States)

    Polke, Melanie; Leonhardt, Ines; Kurzai, Oliver; Jacobsen, Ilse D

    2018-03-01

    Candida albicans is a successful colonizer of the human host, which can, under certain circumstances cause a range of clinically diverse infections. Important virulence-associated traits of the fungus, such as the dimorphic switch and biofilm formation, are controlled by the quorum sensing molecule farnesol. Given the potential of farnesol as a novel antifungal drug, there has been increasing research into the mechanism underlying farnesol sensing and action in C. albicans. However, despite the identification of various factors involved in farnesol signalling, its exact mode of action remains largely unclear. This review provides an overview of the currently known aspects of farnesol production, sensing and action within C. albicans. We also illustrate the characteristic of C. albicans to simultaneously produce and tolerate high farnesol concentrations that are lethal to other microbes. Furthermore, we summarize new literature on the role of farnesol in the interaction of C. albicans with the human host and highlight its action as a potent immunomodulatory molecule.

  19. Proper Sterol Distribution Is Required for Candida albicans Hyphal Formation and Virulence

    Science.gov (United States)

    McCourt, Paula; Liu, Hsing-Yin; Parker, Josie E.; Gallo-Ebert, Christina; Donigan, Melissa; Bata, Adam; Giordano, Caroline; Kelly, Steven L.; Nickels, Joseph T.

    2016-01-01

    Candida albicans is an opportunistic fungus responsible for the majority of systemic fungal infections. Multiple factors contribute to C. albicans pathogenicity. C. albicans strains lacking CaArv1 are avirulent. Arv1 has a conserved Arv1 homology domain (AHD) that has a zinc-binding domain containing two cysteine clusters. Here, we explored the role of the CaAHD and zinc-binding motif in CaArv1-dependent virulence. Overall, we found that the CaAHD was necessary but not sufficient for cells to be virulent, whereas the zinc-binding domain was essential, as Caarv1/Caarv1 cells expressing the full-length zinc-binding domain mutants, Caarv1C3S and Caarv1C28S, were avirulent. Phenotypically, we found a direct correlation between the avirulence of Caarv1/Caarv1, Caarrv1AHD, Caarv1C3S, and Caarv1C28S cells and defects in bud site selection, septa formation and localization, and hyphal formation and elongation. Importantly, all avirulent mutant strains lacked the ability to maintain proper sterol distribution. Overall, our results have established the importance of the AHD and zinc-binding domain in fungal invasion, and have correlated an avirulent phenotype with the inability to maintain proper sterol distribution. PMID:27587298

  20. Proper Sterol Distribution Is Required for Candida albicans Hyphal Formation and Virulence

    Directory of Open Access Journals (Sweden)

    Paula McCourt

    2016-11-01

    Full Text Available Candida albicans is an opportunistic fungus responsible for the majority of systemic fungal infections. Multiple factors contribute to C. albicans pathogenicity. C. albicans strains lacking CaArv1 are avirulent. Arv1 has a conserved Arv1 homology domain (AHD that has a zinc-binding domain containing two cysteine clusters. Here, we explored the role of the CaAHD and zinc-binding motif in CaArv1-dependent virulence. Overall, we found that the CaAHD was necessary but not sufficient for cells to be virulent, whereas the zinc-binding domain was essential, as Caarv1/Caarv1 cells expressing the full-length zinc-binding domain mutants, Caarv1C3S and Caarv1C28S, were avirulent. Phenotypically, we found a direct correlation between the avirulence of Caarv1/Caarv1, Caarrv1AHD, Caarv1C3S, and Caarv1C28S cells and defects in bud site selection, septa formation and localization, and hyphal formation and elongation. Importantly, all avirulent mutant strains lacked the ability to maintain proper sterol distribution. Overall, our results have established the importance of the AHD and zinc-binding domain in fungal invasion, and have correlated an avirulent phenotype with the inability to maintain proper sterol distribution.

  1. The Role of Isocitrate Lyase (ICL1) in the Metabolic Adaptation of Candida albicans Biofilms

    Science.gov (United States)

    Ishola, Oluwaseun Ayodeji; Ting, Seng Yeat; Tabana, Yasser M; Ahmed, Mowaffaq Adam; Yunus, Muhammad Amir; Mohamed, Rafeezul; Lung Than, Leslie Thian; Sandai, Doblin

    2016-01-01

    Background A major characteristic of Candida biofilm cells that differentiates them from free-floating cells is their high tolerance to antifungal drugs. This high resistance is attributed to particular biofilm properties, including the accumulation of extrapolymeric substances, morphogenetic switching, and metabolic flexibility. Objectives This study evaluated the roles of metabolic processes (in particular the glyoxylate cycle) on biofilm formation, antifungal drug resistance, morphology, and cell wall components. Methods Growth, adhesion, biofilm formation, and cell wall carbohydrate composition were quantified for isogenic Candida albicans ICL1/ICL1, ICL1/icl1, and icl1/icl1 strains. The morphology and topography of these strains were compared by light microscopy and scanning electron microscopy. FKS1 (glucan synthase), ERG11 (14-α-demethylase), and CDR2 (efflux pump) mRNA levels were quantified using qRT-PCR. Results The ICL1/icl1 and icl1/icl1 strains formed similar biofilms and exhibited analogous drug-tolerance levels to the control ICL1/ICL1 strains. Furthermore, the drug sequestration ability of β-1, 3-glucan, a major carbohydrate component of the extracellular matrix, was not impaired. However, the inactivation of ICL1 did impair morphogenesis. ICL1 deletion also had a considerable effect on the expression of the FKS1, ERG11, and CDR2 genes. FKS1 and ERG11 were upregulated in ICL1/icl1 and icl1/icl1 cells throughout the biofilm developmental stages, and CDR2 was upregulated at the early phase. However, their expression was downregulated compared to the control ICL1/ICL1 strain. Conclusions We conclude that the glyoxylate cycle is not a specific determinant of biofilm drug resistance. PMID:27800147

  2. Light-driven photosensitizer uptake increases Candida albicans photodynamic inactivation.

    Science.gov (United States)

    Romano, Renan A; Pratavieira, Sebastião; Silva, Ana P da; Kurachi, Cristina; Guimarães, Francisco E G

    2017-11-01

    Photodynamic Inactivation (PDI) is based on the use of a photosensitizer (PS) and light that results mainly in the production of reactive oxygen species, aiming to produce microorganism cell death. PS incubation time and light dose are key protocol parameters that influence PDI response; the correct choice of them can increase the efficiency of inactivation. The results of this study show that a minor change in the PDI protocol, namely light-driven incubation leads to a higher photosensitizer and more uniform cell uptake inside the irradiated zone. Furthermore, as the uptake increases, the damage caused by PDI also increases. The proposed light-driven incubation prior to the inactivation illumination dose has advantages when compared to the traditional PDI treatments since it can be more selective and effective. Using a violet light as pre-illumination (light-driven incubation) source and a red-light system as PDI source, it was possible to demonstrate that when compared to the traditional protocol of dark incubation, the pre-illuminated cell culture showed an inactivation increase of 7 log units. These in vitro results performed in Candida albicans cells may result in the introduction of a new protocol for PDI. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. The effectiveness of laser diode induction to Carica Papaya L. chlorophyll extract to be ROS generating in the photodynamic inactivation mechanisms for C.albicans biofilms

    International Nuclear Information System (INIS)

    Astuty, S Dewi; Baktir, A

    2017-01-01

    Research on the effectiveness of photo inactivation of C.albicans biofilms led by a-PDT system mediated by chlorophyll-diode-laser-induced was done. This research was done using in vitro technique in order to effectively determine chlorophyll extract of ROS-generated Carica Papaya L. using in situ technique. This technique induced laser diode on different dose and C. albicans with reduced degree. This research is a preliminary study in efforts to find anew sensitizer agent candidate made of chlorophyll extract and antifungal of Carica Papaya L. The effectiveness of eradication has been tested with MDA’s content and OD of biomass biofilms as well as analyzed using ANOVA and Tukey Test (α=0.05). The characteristic of chlorophyll extract of Carica Papaya L. has maximum absorptions on blue areas (λ max = 420 nm) and red areas (λ max = 670 nm). The MIC value of Carica Papaya L. ’s chlorophyll extract against C. albicans planktonic and biofilms cell is 63.8 μM and 31.9 μM respectively. The result shows that treatment using laser which was combined with chlorophyll extract is more effective than that with laser only or chlorophyll extract only. The treatment using laser combined with chlorophyll extract obtained more than 65% (α=0.05) (more than that of negative control) for P 2 L 1 group with OD 595 0.915. The MDA’s content showed that group of laser which was mediated with chlorophyll extract had larger values than group of laser or chlorophyll extract only. (paper)

  4. Contribution of Fdh3 and Glr1 to Glutathione Redox State, Stress Adaptation and Virulence in Candida albicans

    NARCIS (Netherlands)

    Tillmann, Anna T.; Strijbis, Karin; Cameron, Gary; Radmaneshfar, Elahe; Thiel, Marco; Munro, Carol A.; Maccallum, Donna M.; Distel, Ben; Gow, Neil A. R.; Brown, Alistair J. P.

    2015-01-01

    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

  5. Efficacy of commercial and household denture cleansers against Candida albicans adherent to acrylic denture base resin: An in vitro study

    Directory of Open Access Journals (Sweden)

    M Nanditha Kumar

    2012-01-01

    Conclusion: Within the limitations of this in vitro study, denture cleansers were found to be effective in reducing C albicans cells adhering to dentures. The commercial denture cleansers (Fittydent® and Clinsodent® were more effective than household denture cleansers (vinegar and diluted vinegar.

  6. Dynamics of biofilm formation and the interaction between Candida albicans and methicillin-susceptible (MSSA) and -resistant Staphylococcus aureus (MRSA).

    Science.gov (United States)

    Zago, Chaiene Evelin; Silva, Sónia; Sanitá, Paula Volpato; Barbugli, Paula Aboud; Dias, Carla Maria Improta; Lordello, Virgínia Barreto; Vergani, Carlos Eduardo

    2015-01-01

    Polymicrobial biofilms are an understudied and a clinically relevant problem. This study evaluates the interaction between C. albicans, and methicillin- susceptible (MSSA) and resistant (MRSA) S. aureus growing in single- and dual-species biofilms. Single and dual species adhesion (90 min) and biofilms (12, 24, and 48 h) were evaluated by complementary methods: counting colony-forming units (CFU mL-1), XTT-reduction, and crystal violet staining (CV). The secretion of hydrolytic enzymes by the 48 h biofilms was also evaluated using fluorimetric kits. Scanning electron microscopy (SEM) was used to assess biofilm structure. The results from quantification assays were compared using two-way ANOVAs with Tukey post-hoc tests, while data from enzymatic activities were analyzed by one-way Welch-ANOVA followed by Games-Howell post hoc test (α = 0.05). C. albicans, MSSA and MRSA were able to adhere and to form biofilm in both single or mixed cultures. In general, all microorganisms in both growth conditions showed a gradual increase in the number of cells and metabolic activity over time, reaching peak values between 12 h and 48 h (ρ<0.05). C. albicans single- and dual-biofilms had significantly higher total biomass values (ρ<0.05) than single biofilms of bacteria. Except for single MRSA biofilms, all microorganisms in both growth conditions secreted proteinase and phospholipase-C. SEM images revealed extensive adherence of bacteria to hyphal elements of C. albicans. C. albicans, MSSA, and MRSA can co-exist in biofilms without antagonism and in an apparent synergistic effect, with bacteria cells preferentially associated to C. albicans hyphal forms.

  7. Long-Term Live Cell Imaging of Cell Migration: Effects of Pathogenic Fungi on Human Epithelial Cell Migration.

    Science.gov (United States)

    Wöllert, Torsten; Langford, George M

    2016-01-01

    Long-term live cell imaging was used in this study to determine the responses of human epithelial cells to pathogenic biofilms formed by Candida albicans. Epithelial cells of the skin represent the front line of defense against invasive pathogens such as C. albicans but under certain circumstances, especially when the host's immune system is compromised, the skin barrier is breached. The mechanisms by which the fungal pathogen penetrates the skin and invade the deeper layers are not fully understood. In this study we used keratinocytes grown in culture as an in vitro model system to determine changes in host cell migration and the actin cytoskeleton in response to virulence factors produced by biofilms of pathogenic C. albicans. It is clear that changes in epithelial cell migration are part of the response to virulence factors secreted by biofilms of C. albicans and the actin cytoskeleton is the downstream effector that mediates cell migration. Our goal is to understand the mechanism by which virulence factors hijack the signaling pathways of the actin cytoskeleton to alter cell migration and thereby invade host tissues. To understand the dynamic changes of the actin cytoskeleton during infection, we used long-term live cell imaging to obtain spatial and temporal information of actin filament dynamics and to identify signal transduction pathways that regulate the actin cytoskeleton and its associated proteins. Long-term live cell imaging was achieved using a high resolution, multi-mode epifluorescence microscope equipped with specialized light sources, high-speed cameras with high sensitivity detectors, and specific biocompatible fluorescent markers. In addition to the multi-mode epifluorescence microscope, a spinning disk confocal long-term live cell imaging system (Olympus CV1000) equipped with a stage incubator to create a stable in vitro environment for long-term real-time and time-lapse microscopy was used. Detailed descriptions of these two long-term live

  8. 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

  9. Effect of the Ethyl Acetate Fraction of Eugenia uniflora on Proteins Global Expression during Morphogenesis in Candida albicans.

    Science.gov (United States)

    Silva-Rocha, Walicyranison P; de Azevedo, Matheus F; Ferreira, Magda R A; da Silva, Julhiany de Fátima; Svidzinski, Terezinha I E; Milan, Eveline P; Soares, Luiz A L; Rocha, Keyla B F; Uchôa, Adriana F; Mendes-Giannini, Maria J S; Fusco Almeida, Ana M; Chaves, Guilherme M

    2017-01-01

    Candida albicans is able to switch from yeast to hyphal growth and this is an essential step for tissue invasion and establishment of infection. Due to the limited drug arsenal used to treat fungal infections and the constant emergence of resistant strains, it is important to search for new therapeutic candidates. Therefore, this study aimed to investigate by proteomic analysis the role of a natural product ( Eugenia uniflora ) in impairing hypha formation in C. albicans . We also tested the potential action of E. uniflora to prevent and treat oral candidiasis induced in a murine model of oral infection and the ability of polymorphonuclear neutrophils to phagocytize C. albicans cells treated with the ethyl acetate fraction of the extract. We found that this fraction greatly reduced hypha formation after morphogenesis induction in the presence of serum. Besides, several proteins were differentially expressed in cells treated with the fraction. Surprisingly, the ethyl acetate fraction significantly reduced phagocytosis in C. albicans (Mean 120.36 ± 36.71 yeasts/100 PMNs vs. 44.68 ± 19.84 yeasts/100 PMNs). Oral candidiasis was attenuated when C. albicans cells were either pre-incubated in the presence of E. uniflora or when the fraction was applied to the surface of the oral cavity after infection. These results were consistent with the reduction in CFU counts (2.36 vs. 1.85 Log10 CFU/ml) and attenuation of tissue damage observed with histopathological analysis of animals belonging to treated group. We also observed shorter true hyphae by direct examination and histopathological analysis, when cells were treated with the referred natural product. The E. uniflora ethyl acetate fraction was non-toxic to human cells. E. uniflora may act on essential proteins mainly related to cellular structure, reducing the capacity of filamentation and attenuating infection in a murine model, without causing any toxic effect on human cells, suggesting that it may be a future

  10. The effect of ultraviolet radiation on the pathogenesis of Candida albicans in mice

    International Nuclear Information System (INIS)

    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

  11. 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.

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

    Science.gov (United States)

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

    2013-12-01

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

  13. Plasma membrane organization promotes virulence of the human fungal pathogen Candida albicans

    Science.gov (United States)

    Douglas, Lois M.; Konopka, James. B.

    2017-01-01

    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

  14. 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.

  15. Modelling the regulation of thermal adaptation in Candida albicans, a major fungal pathogen of humans.

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    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.

  16. pH-Dependant Antifungal Activity of Valproic Acid against the Human Fungal Pathogen Candida albicans

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    Julien Chaillot

    2017-10-01

    Full Text Available Current antifungal drugs suffer from limitations including toxicity, the emergence of resistance and decreased efficacy at low pH that are typical of human vaginal surfaces. Here, we have shown that the antipsychotic drug valproic acid (VPA exhibited a strong antifungal activity against both sensitive and resistant Candida albicans in pH condition similar to that encountered in vagina. VPA exerted a strong anti-biofilm activity and attenuated damage of vaginal epithelial cells caused by C. albicans. We also showed that VPA synergizes with the allylamine antifungal, Terbinafine. We undertook a chemogenetic screen to delineate biological processes that underlies VPA-sensitivity in C. albicans and found that vacuole-related genes were required to tolerate VPA. Confocal fluorescence live-cell imaging revealed that VPA alters vacuole integrity and support a model where alteration of vacuoles contributes to the antifungal activity. Taken together, this study suggests that VPA could be used as an effective antifungal against vulvovaginal candidiasis.

  17. Contact-induced apical asymmetry drives the thigmotropic responses of Candida albicans hyphae.

    Science.gov (United States)

    Thomson, Darren D; Wehmeier, Silvia; Byfield, FitzRoy J; Janmey, Paul A; Caballero-Lima, David; Crossley, Alison; Brand, Alexandra C

    2015-03-01

    Filamentous hyphae of the human pathogen, Candida albicans, invade mucosal layers and medical silicones. In vitro, hyphal tips reorient thigmotropically on contact with small obstacles. It is not known how surface topography is sensed but hyphae lacking the cortical marker, Rsr1/Bud1, are unresponsive. We show that, on surfaces, the morphology of hyphal tips and the position of internal polarity protein complexes are asymmetrically skewed towards the substratum and biased towards the softer of two surfaces. In nano-fabricated chambers, the Spitzenkörper (Spk) responded to touch by translocating across the apex towards the point of contact, where its stable maintenance correlated with contour-following growth. In the rsr1Δ mutant, the position of the Spk meandered and these responses were attenuated. Perpendicular collision caused lateral Spk oscillation within the tip until after establishment of a new growth axis, suggesting Spk position does not predict the direction of growth in C. albicans. Acute tip reorientation occurred only in cells where forward growth was countered by hyphal friction sufficient to generate a tip force of ∼ 8.7 μN (1.2 MPa), more than that required to penetrate host cell membranes. These findings suggest mechanisms through which the organization of hyphal tip growth in C. albicans facilitates the probing, penetration and invasion of host tissue. © 2014 The Authors. Cellular Microbiology published by John Wiley & Sons Ltd.

  18. 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.

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

    Science.gov (United States)

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

    2017-01-01

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

  20. 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.

  1. Probiotic lactobacillus and estrogen effects on vaginal epithelial gene expression responses to Candida albicans.

    Science.gov (United States)

    Wagner, R Doug; Johnson, Shemedia J

    2012-06-20

    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. 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. 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. The results suggest that C. albicans infection induces pro-inflammatory responses in vaginal epithelial cells, and estrogen and lactobacilli suppress expression of NF-κB-related inflammatory genes. Probiotic

  2. Contribution of Fdh3 and Glr1 to Glutathione Redox State, Stress Adaptation and Virulence in Candida albicans.

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    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.

  3. Antibiofilm activity of Streptomyces toxytricini Fz94 against Candida albicans ATCC 10231

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    Sheir DH

    2017-06-01

    Full Text Available Candida albicans is a significant cause of morbidity and mortality in immunocompromised patients worldwide. Biofilm formation by Candida species is a significant virulence factor for disease pathogenesis. Keeping in view the importance of Streptomyces' metabolites, the present study was initiated during the bioprospecting programme of Egyptian Streptomyces carried by the authors since 2013. Native Streptomyces isolates were recovered from soil samples collected from different governorates. Antifungal activity of forty isolates of Streptomyces were performed against planktonic (free cells of C. albicans ATCC 10231 and resistant clinical Candida isolates. Streptomyces isolates showed high inhibition activity against free cells of Candida were further assayed against biofilm of C. albicans reference strain. The most active Streptomyces sp. (no.6 was identified phenotypically, biochemically and by using 16S rRNA. The 16S rRNA sequences obtained were compared with those deposited in the GenBank Database and registered with accession number KM052378 as S. toxytricini Fz94. Screening of S. toxytricini Fz94 extract capability in prevention and destruction of C. albicans reference strain biolfilm was assessed by resazurin dye adopted technique. In the pre-exposure scheme, the lowest concentration of 5 gL-1 showed biofilm viability inhibition of 92% after 120 min, while Ketoconazole® gave 90 % inhibition at concentration of 2 gL-1. In post exposure, the concentration of S. toxytricini Fz94 extract 7gL-1 caused 82 % inhibition of biofilms viability after 120 min, while Ketoconazole did not show any destruction capability. The cytotoxicity of S. toxytricini Fz94 crude extract results showed that it was nontoxic at 10 gL-1. S. toxytricini Fz94 is maintained in the Fungarium of Arab Society for Fungal Conservation (ASFC with accession number FSCU-2017-1110.

  4. Lasioglossins LLIII affect the morphogenesis of Candida albicans and reduces the duration of experimental vaginal candidiasis in mice.

    Science.gov (United States)

    Vrablikova, Alena; Czernekova, Lydie; Cahlikova, Romana; Novy, Zbynek; Petrik, Milos; Imran, Saima; Novak, Zdenek; Krupka, Michal; Cerovsky, Vaclav; Turanek, Jaroslav; Raska, Milan

    2017-11-01

    Lasioglossins are a group of peptides with identified antimicrobial activity. The inhibitory effects of two synthetic lasioglossin derivatives, LLIII and D-isomeric variant LLIII-D, on morphological changes in Candida albicans in vitro and the effect of local administration of LLIII during experimental murine candidiasis were investigated. C. albicans blastoconidia were grown in the presence of lasioglossin LLIII or LLIII-D at concentrations of 11.5 μM and 21 μM, respectively, for 1, 2 and 3 days and their viability determined by flow cytometry using eosin Y staining. Morphological changes were examined by light and fluorescent microscopy. The Candida-inhibitory effect of daily intravaginal administration of 0.7 or 1.4 μg of LLIII was assessed in mice with experimentally-induced vaginal candidiasis. LLIII and LLIII-D lasioglossins exhibited candidacidal activity in vitro (>76% after 24 hr and >84% after 48 hr of incubation). After 72 hr incubation of Candida with low concentration of lasioglossins, an increase in viability was detected, probably due to a Candida antimicrobial peptides evasion strategy. Furthermore, lasioglossins inhibited temperature-induced morphotype changes toward hyphae and pseudohyphae with sporadic occurrence of atypical cells with two or enlarged nuclei, suggesting interference with mitosis or cytokinesis. Local application of LLIII reduced the duration of experimental candidiasis with no evidence of adverse effects. Lasioglossin LLIII is a promising candidate for development as an antimicrobial drug for treating the vaginal candidiasis. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

  5. Solar Cell Capacitance Determination Based on an RLC Resonant Circuit

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    Petru Adrian Cotfas

    2018-03-01

    Full Text Available The capacitance is one of the key dynamic parameters of solar cells, which can provide essential information regarding the quality and health state of the cell. However, the measurement of this parameter is not a trivial task, as it typically requires high accuracy instruments using, e.g., electrical impedance spectroscopy (IS. This paper introduces a simple and effective method to determine the electric capacitance of the solar cells. An RLC (Resistor Inductance Capacitor circuit is formed by using an inductor as a load for the solar cell. The capacitance of the solar cell is found by measuring the frequency of the damped oscillation that occurs at the moment of connecting the inductor to the solar cell. The study is performed through simulation based on National Instruments (NI Multisim application as SPICE simulation software and through experimental capacitance measurements of a monocrystalline silicon commercial solar cell and a photovoltaic panel using the proposed method. The results were validated using impedance spectroscopy. The differences between the capacitance values obtained by the two methods are of 1% for the solar cells and of 9.6% for the PV panel. The irradiance level effect upon the solar cell capacitance was studied obtaining an increase in the capacitance in function of the irradiance. By connecting different inductors to the solar cell, the frequency effect upon the solar cell capacitance was studied noticing a very small decrease in the capacitance with the frequency. Additionally, the temperature effect over the solar cell capacitance was studied achieving an increase in capacitance with temperature.

  6. 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

  7. 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.

  8. Comparison of the Candida albicans and biofilm formation amount on natural tooth,

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    Serdar Polat

    2012-03-01

    Full Text Available Objective: This study compared the retention of the Candidaalbicans and biofilm formation on natural teeth, porcelainand acrylic resin.Materials and methods: Samples are taken with thesterile ecuvion sticks from the buccal embrasures of thenatural tooth, porcelain and acrylic. The biofilm productionof candida reproducing strains was determined withmicroplate method. Samples are settled in 0.5 ml sterilephosphate buffered saline. Reproduction detected coloniesdefined to species in accordance with their macroscopicand microscopic features and germ tube test inmicrobiology laboratory.Results: There was significant differences for retention ofCandida albicans and biofilm formation on the surface oftooth, porcelain and acrylic (p<0.05.Conclusion: Adherence of Candida albicans and biofilmformation on the porcelain significantly less than naturaltooth and acrylic, and retention and biofilm formation onthe tooth less than acrylic.

  9. 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. The effect of submersion denture base acrylic resin in a betel leaf ekstract solution against growth Candida albicans

    Directory of Open Access Journals (Sweden)

    Andi Izham

    2016-06-01

    Full Text Available Denture base is a protesa which replace some or all of the lost original teeth and surrounding tissues. The Pupose of making protesa is for restore the function, appearance, comfort and impaired health result lost teeth. One part of the denture base is base plate. Microorganisms are often found in the oral cavity is Candida albicans (C.albicans approximately 40% in the oral cavity.C.albicans can penetrate the acrylic resin that can infect the soft tissue and is the cause of denture stomatitis therefore the disinfection of denture base is a important factor that must be done. In general betel leaves contant up to 4.2% essential oil compounds and phenyl propanoid and tannin. These compounds is a antimicroba and antifungal which can inhibit the growth of several type of bacteria among others Escherichia coli, Salmonella sp, Staphylococcus aurens, Klebstella, Pasteurella and can turn off the C.albicans. The purpose of the research is to determine how the effect of submersion denture base acrylic resin in a betel leaf ekstract solution against growth C.albicans.Type of research is an experimental laboratory with a longitudinal design (follow-up study. The sampling method used is total sampling. The results showed that the number of C.albicans colonies n denture base acrylic resin which soaked betel leaf extract solution that the dilution 10-1  with consentration 2.5% total colony count is 2 and the results 2.0 x 101 CFU/ml, on a control solution that the dilution 10-2 total colony 355 and the result 3.55 x 104 CFU/ml, that the dilution  10-3 total colony 62 and the result 6.2 x 104 CFU/ml.

  11. 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.

  12. 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.

  13. 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…

  14. Real-Time Determination of Solar Cell Parameters

    Science.gov (United States)

    Hassan Ali, Mohamed; Rabhi, Abdelhamid; Haddad, Sofiane; El Hajjaji, Ahmed

    2017-11-01

    The extraction of solar cell parameters is a difficult task but is an important step in the assessment procedure of solar cells and panels. This work presents numerical methods for determining these parameters and compares their performances under different solar irradiances when they are implemented in an equivalent electrical circuit model with one or two diodes. To obtain a fast convergence rate in real-time applications, the fractional-order Darwinian particle swarm optimization (FODPSO) method is used through experimental data collected from a platform of photovoltaic (PV) energy installed near the modeling, information and systems laboratory at Amiens, France. The results showed that the one-diode model is less representative than the two-diode model. Furthermore, it is envisaged that the proposed FODPSO-based extraction method is more effective in modeling with two diodes. This will allow real-time determination of solar cells parameters and consequently will help to select the most suitable PV model.

  15. 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.

  16. Stage-specific sampling by pattern recognition receptors during Candida albicans phagocytosis.

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    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.

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

    Science.gov (United States)

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

    2016-11-01

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

  18. Inhibitory Effect of Curcumin on Candida-albicans compared with Nystatin: an in-vitro Study

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    Neda Babaii

    2016-10-01

    Full Text Available Introduction: Curcumin is the active ingredient in the traditional herbal remedy and dietary spice turmeric (Curcuma longa. Curcumin has a surprisingly wide range of beneficial properties, including anti-inflammatory, antioxidant, chemopreventive and chemotherapeutic activity. on basis of recent studies; it has antifungal and antibacterial effects. The aim of this study was in-vitro evaluation of antifungal effect of curcumin on candida albicans and comparing it with nystatin. Methods: after preparing curcumin powder, 3 laboratory methods were used to evaluate antifungal effect. The first method was cell count technique, used to evaluate the amount of candida albicans after time, in different concentrations of curcumin in Dimethyl sulfoxide (DMSO. The second was cup bioassay, in which inhibitory a zone of curcumin in DMSO was evaluated in sabouraud culture plates; and in third method, inhibitory zones of dried disks; which contained curcumin in DMSO were evaluated. Results: the result of all three methods showed that curcumin has antifungal effect and this effect increases in more concentrations. Conclusion: curcumin has apparent and dose dependent antifungal effect on candida albicans.

  19. 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

    2012-01-01

    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 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

  20. Saponins of Trifolium spp. Aerial Parts as Modulators of Candida Albicans Virulence Attributes

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    Aleksandra Budzyńska

    2014-07-01

    Full Text Available The aim was to provide the insight into the biology of C. albicans influenced by undescribed yet properties of saponin-rich (80%–98% fractions (SAPFs, isolated from extracts of Trifolium alexandrinum, T. incarnatum, T. resupinatum var. resupinatum aerial parts. Their concentrations below 0.5 mg/mL were arbitrarily considered as subMICs for C. albicans ATCC 10231 and were further used. SAPFs affected yeast enzymatic activity, lowered tolerance to the oxidative stress, to the osmotic stress and to the action of the cell wall disrupting agent. In their presence, germ tubes formation was significantly and irreversibly inhibited, as well as Candida invasive capacity. The evaluation of SAPFs interactions with anti-mycotics showed synergistic activity, mainly with azoles. Fluconazole MIC was lowered—susceptible C. albicans ATCC 10231 was more susceptible, and resistant C. glabrata (clinical strain become more susceptible (eightfold. Moreover, the tested samples showed no hemolytic activity and at the concentrations up to 0.5 mg/mL did not reduce viability of fibroblasts L929. This study provided the original evidence that SAPFs of Trifolium spp. aerial part exhibit significant antimicrobial activity, by reduce the expression/quantity of important Candida virulence factors and have good potential for the development of novel antifungal products supporting classic drugs.

  1. Molecular genetic techniques for gene manipulation in Candida albicans.

    Science.gov (United States)

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

    2014-05-15

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

  2. Evaluation of Candida Albicans Biofilm Formation on Various Dental ...

    African Journals Online (AJOL)

    2016-06-24

    Jun 24, 2016 ... This study compared the susceptibility of six dental restorative materials to Candida albicans adhesion. ... found for the composite and the compomer samples. ..... Candida colonization on acrylic resins and denture liners:.

  3. Budding off: bringing functional genomics to Candida albicans

    Science.gov (United States)

    Anderson, Matthew Z.

    2016-01-01

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

  4. Impact of Environmental Conditions on the Form and Function of Candida albicans Biofilms

    Science.gov (United States)

    Daniels, Karla J.; Park, Yang-Nim; Srikantha, Thyagarajan; Pujol, Claude

    2013-01-01

    Candida albicans, like other pathogens, can form complex biofilms on a variety of substrates. However, as the number of studies of gene regulation, architecture, and pathogenic traits of C. albicans biofilms has increased, so have differences in results. This suggests that depending upon the conditions employed, biofilms may vary widely, thus hampering attempts at a uniform description. Gene expression studies suggest that this may be the case. To explore this hypothesis further, we compared the architectures and traits of biofilms formed in RPMI 1640 and Spider media at 37°C in air. Biofilms formed by a/α cells in the two media differed to various degrees in cellular architecture, matrix deposition, penetrability by leukocytes, fluconazole susceptibility, and the facilitation of mating. Similar comparisons of a/a cells in the two media, however, were made difficult given that in air, although a/a cells form traditional biofilms in RPMI medium, they form polylayers composed primarily of yeast cells in Spider medium. These polylayers lack an upper hyphal/matrix region, are readily penetrated by leukocytes, are highly fluconazole susceptible, and do not facilitate mating. If, however, air is replaced with 20% CO2, a/a cells make a biofilm in Spider medium similar architecturally to that of a/α cells, which facilitates mating. A second, more cursory comparison is made between the disparate cellular architectures of a/a biofilms formed in air in RPMI and Lee's media. The results demonstrate that C. albicans forms very different types of biofilms depending upon the composition of the medium, level of CO2 in the atmosphere, and configuration of the MTL locus. PMID:23954841

  5. 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.

  6. Influence of artificial saliva in biofilm formation of Candida albicans in vitro

    Directory of Open Access Journals (Sweden)

    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.

  7. Processing of Candida albicans Ece1p Is Critical for Candidalysin Maturation and Fungal Virulence

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    Jonathan P. Richardson

    2018-01-01

    Full Text Available Candida albicans is an opportunistic fungal pathogen responsible for superficial and life-threatening infections in humans. During mucosal infection, C. albicans undergoes a morphological transition from yeast to invasive filamentous hyphae that secrete candidalysin, a 31-amino-acid peptide toxin required for virulence. Candidalysin damages epithelial cell plasma membranes and stimulates the activating protein 1 (AP-1 transcription factor c-Fos (via p38–mitogen-activated protein kinase [MAPK], and the MAPK phosphatase MKP1 (via extracellular signal-regulated kinases 1 and 2 [ERK1/2]–MAPK, which trigger and regulate proinflammatory cytokine responses, respectively. The candidalysin toxin resides as a discrete cryptic sequence within a larger 271-amino-acid parental preproprotein, Ece1p. Here, we demonstrate that kexin-like proteinases, but not secreted aspartyl proteinases, initiate a two-step posttranslational processing of Ece1p to produce candidalysin. Kex2p-mediated proteolysis of Ece1p after Arg61 and Arg93, but not after other processing sites within Ece1p, is required to generate immature candidalysin from Ece1p, followed by Kex1p-mediated removal of a carboxyl arginine residue to generate mature candidalysin. C. albicans strains harboring mutations of Arg61 and/or Arg93 did not secrete candidalysin, were unable to induce epithelial damage and inflammatory responses in vitro, and showed attenuated virulence in vivo in a murine model of oropharyngeal candidiasis. These observations identify enzymatic processing of C. albicans Ece1p by kexin-like proteinases as crucial steps required for candidalysin production and fungal pathogenicity.

  8. 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.

  9. Towards automated diffraction tomography. Part II-Cell parameter determination

    International Nuclear Information System (INIS)

    Kolb, U.; Gorelik, T.; Otten, M.T.

    2008-01-01

    Automated diffraction tomography (ADT) allows the collection of three-dimensional (3d) diffraction data sets from crystals down to a size of only few nanometres. Imaging is done in STEM mode, and diffraction data are collected with quasi-parallel beam nanoelectron diffraction (NED). Here, we present a set of developed processing steps necessary for automatic unit-cell parameter determination from the collected 3d diffraction data. Cell parameter determination is done via extraction of peak positions from a recorded data set (called the data reduction path) followed by subsequent cluster analysis of difference vectors. The procedure of lattice parameter determination is presented in detail for a beam-sensitive organic material. Independently, we demonstrate a potential (called the full integration path) based on 3d reconstruction of the reciprocal space visualising special structural features of materials such as partial disorder. Furthermore, we describe new features implemented into the acquisition part

  10. 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...

  11. Aktivitas Antijamur Senyawa Bioaktif Ekstrak Gelidium Latifolium Terhadap Candida Albicans

    OpenAIRE

    Lutfiyanti, Rosiska; Ma'ruf, Widodo Farid; Dewi, Eko Nurcahya

    2012-01-01

    Gelidium sp. has bioactive compounds which is estimated has potential activity as antifungal. The aim of this study were to know bioactive compounds from Gelidium latifolium with different solvent, to know the potency of Gelidium latifolium extract as antifungal towards C. albicans and to know the effect of different concentration of Gelidium latifolium extract towards antifungal activity. The result showed that the methanol extract is able to produce inhibition zones toward Candida albicans,...

  12. Allergen cross-reactivity between Pityrosporum orbiculare and Candida albicans.

    Science.gov (United States)

    Huang, X; Johansson, S G; Zargari, A; Nordvall, S L

    1995-08-01

    Pityrosporum orbiculare and Candida albicans extracts were separated by SDS-PAGE, and IgE binding was detected by immunoblotting with 21 patient sera that were RAST positive to both yeasts. Cross-wise inhibition was performed of IgE binding of a serum pool containing IgE antibodies to both yeasts. The pool was mixed with serial dilutions of P. orbiculare or C. albicans extracts, and incubated with strips containing separated allergen. IgE binding was quantified by densitometric scanning and percent inhibition was calculated as well as the respective ratios between required extract concentration for 50% inhibition in heterologous compared to homologous inhibition for each component (inhibition ratio). Ten components of P. orbiculare were detected by more than 60% of the sera. IgE binding to C. albicans was weak, and only to four bands was IgE binding detected by more than 30% of the sera. The most important C. albicans allergen was a 48-kDa band, to which IgE of half of the patient sera bound. There was little inhibition of IgE binding to P. orbiculare with C. albicans. Thus, all but three components exhibited an inhibition ratio higher than 100. The inhibition ratio of the 48-kDa C. albicans compound was 50, thus indicating some degree of cross-reactivity. Significant cross-reactivity was shown by C. albicans compounds of 18, 24, 26, 34, and 38 kDa, the inhibition ratios of which were less than 10. There was some degree of cross-reactivity between apparent protein allergens of the two yeasts, but IgE antibodies to C. albicans do not merely reflect sensitization to P. orbiculare.

  13. Selected microRNAs define cell fate determination of murine central memory CD8 T cells.

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    Gonzalo Almanza

    2010-06-01

    Full Text Available During an immune response T cells enter memory fate determination, a program that divides them into two main populations: effector memory and central memory T cells. Since in many systems protection appears to be preferentially mediated by T cells of the central memory it is important to understand when and how fate determination takes place. To date, cell intrinsic molecular events that determine their differentiation remains unclear. MicroRNAs are a class of small, evolutionarily conserved RNA molecules that negatively regulate gene expression, causing translational repression and/or messenger RNA degradation. Here, using an in vitro system where activated CD8 T cells driven by IL-2 or IL-15 become either effector memory or central memory cells, we assessed the role of microRNAs in memory T cell fate determination. We found that fate determination to central memory T cells is under the balancing effects of a discrete number of microRNAs including miR-150, miR-155 and the let-7 family. Based on miR-150 a new target, KChIP.1 (K (+ channel interacting protein 1, was uncovered, which is specifically upregulated in developing central memory CD8 T cells. Our studies indicate that cell fate determination such as surface phenotype and self-renewal may be decided at the pre-effector stage on the basis of the balancing effects of a discrete number of microRNAs. These results may have implications for the development of T cell vaccines and T cell-based adoptive therapies.

  14. The determinants of alternative RNA splicing in human cells.

    Science.gov (United States)

    Ramanouskaya, Tatsiana V; Grinev, Vasily V

    2017-12-01

    Alternative splicing represents an important level of the regulation of gene function in eukaryotic organisms. It plays a critical role in virtually every biological process within an organism, including regulation of cell division and cell death, differentiation of tissues in the embryo and the adult organism, as well as in cellular response to diverse environmental factors. In turn, studies of the last decade have shown that alternative splicing itself is controlled by different mechanisms. Unfortunately, there is no clear understanding of how these diverse mechanisms, or determinants, regulate and constrain the set of alternative RNA species produced from any particular gene in every cell of the human body. Here, we provide a consolidated overview of alternative splicing determinants including RNA-protein interactions, epigenetic regulation via chromatin remodeling, coupling of transcription-to-alternative splicing, effect of secondary structures in pre-RNA, and function of the RNA quality control systems. We also extensively and critically discuss some mechanistic insights on coordinated inclusion/exclusion of exons during the formation of mature RNA molecules. We conclude that the final structure of RNA is pre-determined by a complex interplay between cis- and trans-acting factors. Altogether, currently available empirical data significantly expand our understanding of the functioning of the alternative splicing machinery of cells in normal and pathological conditions. On the other hand, there are still many blind spots that require further deep investigations.

  15. 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

  16. Biofilm development by blastospores and hyphae of Candida albicans on abraded denture acrylic resin surfaces.

    Science.gov (United States)

    Jackson, Sarah; Coulthwaite, Lisa; Loewy, Zvi; Scallan, Anthony; Verran, Joanna

    2014-10-01

    Candida albicans is a known etiologic agent of denture stomatitis. Candida hyphae exhibit the ability to respond directionally to environmental stimuli. This characteristic is thought to be important in the penetration of substrata such as resilient denture liners and host epithelium. It has been suggested that hyphal production also enhances adhesion and survival of Candida on host and denture surfaces. Surface roughness, in addition, can enhance adhesion where stronger interactions occur between cells and surface features of similar dimensions. The purpose of this study was to assess the development of hyphal and blastospore biofilms on abraded denture acrylic resin specimens and measure the ease of removal of these biofilms. Biofilms were grown for 48 hours on abraded 1-cm² denture acrylic resin specimens from adhered hyphal phase C albicans or from adhered blastospores. Subsequently, all specimens were stained with Calcofluor White and examined with confocal scanning laser microscopy. Biofilms were removed by vortex mixing in sterile phosphate buffered saline solution. Removed cells were filtered (0.2-μm pore size). Filters were dried at 37°C for 24 hours for dry weight measurements. Any cells that remained on the acrylic resin specimens were stained with 0.03% acridine orange and examined with epifluorescence microscopy. Biofilms grown from both cell types contained all morphologic forms of C albicans. Although the underlying surface topography did not affect the amount of biofilm produced, biofilms grown from hyphal phase Candida were visibly thicker and had greater biomass (Phyphae in early Candida biofilms increased biofilm mass and resistance to removal. Increased surface roughness enhances retention of hyphae and yeast cells, and, therefore, will facilitate plaque regrowth. Therefore, minimization of denture abrasion during cleaning is desirable. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All

  17. Determination of thymidine in serum used for cell culture media

    International Nuclear Information System (INIS)

    Schaer, J.C.; Maurer, U.; Schindler, R.

    1978-01-01

    Thymidine concentrations in serum used for cell culture media were determined with an assay based on isotope dilution. In this assay, incorporation of (3H)-thymidine into DNA of cultured cells was measured in the presence of 5 and 20% serum as a function of the concentration of unlabeled thymidine added to the medium. Thymidine concentrations were measured using horse serum as well as fetal calf serum in the culture media. Dialysis of serum resulted in a reduction of thymidine levels by factors of at least 10

  18. Sapodilla (Manilkara zapota Broth as an Alternative Media for Candida albicans

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    Chen Chui Ying

    2017-03-01

    Full Text Available Objective: To determine whether sapodilla can be used to grow Candida albicans. Among all the high galactose and arabinose content fruits, the sapodilla was chosen because it is available year round and can get easily in market. Other than that, it also contains vitamins, calcium and phosphorus which are very useful for fungi growth. Methods: This study used an experimental study as a method of research. The researcher culture Candida albicans on the experimental sapodilla media and identifies the morphology of the fungi by using Gram staining method. The experiment will be replicated two times to get accurate result. The procedure of this experiment constitute of sapodilla media preparation, sapodilla media observation, organism preparation, planting and incubation, observation of fungal colonies and identification of the fungi. Results: In 0%, there was no fungal growth at all. In 5%, there was mild density of fungal colonies. In 10%, there was moderate density of fungal colonies and in 15% the fungal grew with very dense colonies. Conclusions: Sapodilla (Manilkara zapota broth can be used as an alternative media for Candida albicans.

  19. Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin

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    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. Metabolic rate determines haematopoietic stem cell self-renewal.

    Science.gov (United States)

    Sastry, P S R K

    2004-01-01

    The number of haematopoietic stem cells (HSCs) per animal is conserved across species. This means the HSCs need to maintain hematopoiesis over a longer period in larger animals. This would result in the requirement of stem cell self-renewal. At present the three existing models are the stochastic model, instructive model and the third more recently proposed is the chiaro-scuro model. It is a well known allometric law that metabolic rate scales to the three quarter power. Larger animals have a lower metabolic rate, compared to smaller animals. Here it is being hypothesized that metabolic rate determines haematopoietic stem cell self-renewal. At lower metabolic rate the stem cells commit for self-renewal, where as at higher metabolic rate they become committed to different lineages. The present hypothesis can explain the salient features of the different models. Recent findings regarding stem cell self-renewal suggest an important role for Wnt proteins and their receptors known as frizzleds, which are an important component of cell signaling pathway. The role of cGMP in the Wnts action provides further justification for the present hypothesis as cGMP is intricately linked to metabolic rate. One can also explain the telomere homeostasis by the present hypothesis. One prediction of the present hypothesis is with reference to the limit of cell divisions known as Hayflick limit, here it is being suggested that this is the result of metabolic rate in laboratory conditions and there can be higher number of cell divisions in vivo if the metabolic rate is lower. Copyright 2004 Elsevier Ltd.

  1. Antimicrobial activity of apple cider vinegar against Escherichia coli, Staphylococcus aureus and Candida albicans; downregulating cytokine and microbial protein expression.

    Science.gov (United States)

    Yagnik, Darshna; Serafin, Vlad; J Shah, Ajit

    2018-01-29

    The global escalation in antibiotic resistance cases means alternative antimicrobials are essential. The aim of this study was to investigate the antimicrobial capacity of apple cider vinegar (ACV) against E. coli, S. aureus and C. albicans. The minimum dilution of ACV required for growth inhibition varied for each microbial species. For C. albicans, a 1/2 ACV had the strongest effect, S. aureus, a 1/25 dilution ACV was required, whereas for E-coli cultures, a 1/50 ACV dilution was required (p < 0.05). Monocyte co-culture with microbes alongside ACV resulted in dose dependent downregulation of inflammatory cytokines (TNFα, IL-6). Results are expressed as percentage decreases in cytokine secretion comparing ACV treated with non-ACV treated monocytes cultured with E-coli (TNFα, 99.2%; IL-6, 98%), S. aureus (TNFα, 90%; IL-6, 83%) and C. albicans (TNFα, 83.3%; IL-6, 90.1%) respectively. Proteomic analyses of microbes demonstrated that ACV impaired cell integrity, organelles and protein expression. ACV treatment resulted in an absence in expression of DNA starvation protein, citrate synthase, isocitrate and malate dehydrogenases in E-coli; chaperone protein DNak and ftsz in S. aureus and pyruvate kinase, 6-phosphogluconate dehydrogenase, fructose bisphosphate were among the enzymes absent in C.albican cultures. The results demonstrate ACV has multiple antimicrobial potential with clinical therapeutic implications.

  2. Inhibition of Candida albicans Biofilm Formation by the Synthetic Lactoferricin Derived Peptide hLF1-11.

    Science.gov (United States)

    Morici, Paola; Fais, Roberta; Rizzato, Cosmeri; Tavanti, Arianna; Lupetti, Antonella

    2016-01-01

    The aim of this study was to evaluate the in vitro activity of the synthetic peptide hLF1-11 against biofilm produced by clinical isolates of Candida albicans with different fluconazole susceptibility. The antibiofilm activity of the peptide hLF1-11 was assessed in terms of reduction of biofilm cellular density, metabolic activity and sessile cell viability. The extent of morphogenesis in hLF1-11 treated and untreated biofilms was also investigated microscopically. Transcription levels of genes related to cell adhesion, hyphal development and extracellular matrix production were analysed by qRT-PCR in hLF1-11 treated and untreated biofilms. Exogenous dibutyryl-cAMP (db-cAMP) was used to rescue morphogenesis in cells exposed to the peptide. The results revealed that hLF1-11 exhibited an inhibitory effect on biofilm formation by all C. albicans isolates tested in a dose-dependent manner, regardless of their fluconazole susceptibility. Visual inspection of treated or untreated biofilm cells with an inverted microscope revealed a significant reduction in hyphal formation by hLF1-11 treated cells, as early as 3 hours of incubation. Moreover, hLF1-11 showed a reduced activity on preadherent cells. hLF1-11 induced the down-regulation of biofilm and hyphal-associated genes, which were predominantly regulated via the Ras1-cAMP-Efg1 pathway. Indeed, exogenous db-cAMP restored morphogenesis in hLF1-11 treated cells. The hLF1-11 peptide significantly inhibited biofilm formation by C. albicans mainly at early stages, interfering with biofilm cellular density and metabolic activity, and affected morphogenesis through the Ras1-cAMP-Efg1 pathway. Our findings provide the first evidence that hLF1-11 could represent a potential candidate for the prevention of biofilm formation by C. albicans.

  3. Molecular and Genetic Determinants of Glioma Cell Invasion

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    Kenta Masui

    2017-12-01

    Full Text Available A diffusely invasive nature is a major obstacle in treating a malignant brain tumor, “diffuse glioma”, which prevents neurooncologists from surgically removing the tumor cells even in combination with chemotherapy and radiation. Recently updated classification of diffuse gliomas based on distinct genetic and epigenetic features has culminated in a multilayered diagnostic approach to combine histologic phenotypes and molecular genotypes in an integrated diagnosis. However, it is still a work in progress to decipher how the genetic aberrations contribute to the aggressive nature of gliomas including their highly invasive capacity. Here we depict a set of recent discoveries involving molecular genetic determinants of the infiltrating nature of glioma cells, especially focusing on genetic mutations in receptor tyrosine kinase pathways and metabolic reprogramming downstream of common cancer mutations. The specific biology of glioma cell invasion provides an opportunity to explore the genotype-phenotype correlation in cancer and develop novel glioma-specific therapeutic strategies for this devastating disease.

  4. Effects of Antifungal Soaked Silicone Hydrogel Contact Lenses on Candida albicans in an Agar Eye Model.

    Science.gov (United States)

    Phan, Chau-Minh; Bajgrowicz, Magdalena; McCanna, David J; Subbaraman, Lakshman N; Jones, Lyndon

    2016-09-01

    To evaluate the effects of two commercial silicone hydrogel contact lenses (CLs) soaked with natamycin (NA) or fluconazole (FL) on the growth of Candida albicans in an in vitro eye model. Three-D printed molds were used as a cast for making eye-shaped models comprising potato dextrose agar. Senofilcon A (SA) and lotrafilcon B (LB) CLs were incubated with either 2 mL of NA or FL at a concentration of 1 mg/mL for 24 hr. To simulate a fungal infection, the eye models were coated with C. albicans. The drug-soaked lenses were placed on top of the eye models. Seven experimental conditions were examined: (1) NA-SA, (2) NA-LB, (3) FL-SA, (4) FL-LB, (5) SA, (6) LB, and (7) control-no lens. At specified time points (t=1, 8, 16, 24, 48 hr), the agar eyes from each experimental condition were removed from the incubator and photographed. The yeast cells from the 24 and 48 hr time point were also analyzed using light microscopy. At 24 and 48 hr, there was considerable growth observed for all conditions except for the NA-SA and NA-LB conditions. When observed under the microscope at 24 and 48 hr, the morphology of the yeast cells in the FL-SA and SA condition were similar to that of the control (oval shaped). There was limited hyphae growth observed for LB and significant visible hyphae growth for the NA-LB group. For NA-SA, NA-LB, and FL-LB groups, the cells were significantly smaller compared with the control. For NA-SA and NA-LB, there was limited growth of C. albicans observed on the eye models even after 48 hr. Under the microscope, the cell morphology differ noticeably between each testing condition, and is dependent on drug-lens combinations.

  5. DETERMINANTS OF RED-BLOOD-CELL DEFORMABILITY IN RELATION TO CELL AGE

    NARCIS (Netherlands)

    BOSCH, FH; WERRE, JM; ROERDINKHOLDERSTOELWINDER, B; HULS, T; WILLEKENS, FLA; WICHERS, G; HALIE, MR

    Red blood cell (RBC) deformability was determined with an ektacytometer in fractions separated on the basis of differences in cell volume or density. Deformability was measured with ektacytometry (rpm-scan and osmo-scan). We studied three groups of RBC fractions:l. By counterflow centrifugation we

  6. Proteomic analysis of protein phosphatase Z1 from Candida albicans.

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    Bernadett Márkus

    Full Text Available Protein phosphatase Z is a "novel type" fungus specific serine/threonine protein phosphatase. Previously our research group identified the CaPPZ1 gene in the opportunistic pathogen Candida albicans and reported that the gene deletion had several important physiological consequences. In order to reveal the protein targets and the associated mechanisms behind the functions of the phosphatase a proteomic method was adopted for the comparison of the cappz1 deletion mutant and the genetically matching QMY23 control strain. Proteins extracted from the control and deletion mutant strains were separated by two-dimensional gel electrophoresis and the protein spots were stained with RuBPS and Pro-Q Diamond in order to visualize the total proteome and the phosphoproteome, respectively. The alterations in spot intensities were determined by densitometry and were analysed with the Delta2D (Decodon software. Spots showing significantly different intensities between the mutant and control strains were excised from the gels and were digested with trypsin. The resulting peptides were identified by LC-MS/MS mass spectrometry. As many as 15 protein spots were found that exhibited significant changes in their intensity upon the deletion of the phosphatase and 20 phosphoproteins were identified in which the level of phosphorylation was modified significantly in the mutant. In agreement with previous findings we found that the affected proteins function in protein synthesis, oxidative stress response, regulation of morphology and metabolism. Among these proteins we identified two potential CaPpz1 substrates (Eft2 and Rpp0 that may regulate the elongation step of translation. RT-qPCR experiments revealed that the expression of the genes coding for the affected proteins was not altered significantly. Thus, the absence of CaPpz1 exerted its effects via protein synthesis/degradation and phosphorylation/dephosphorylation. In addition, our proteomics data strongly

  7. Proteomic analysis of protein phosphatase Z1 from Candida albicans

    Science.gov (United States)

    Pfliegler, Walter P.; Petrényi, Katalin; Boros, Enikő; Pócsi, István; Tőzsér, József; Dombrádi, Viktor

    2017-01-01

    Protein phosphatase Z is a “novel type” fungus specific serine/threonine protein phosphatase. Previously our research group identified the CaPPZ1 gene in the opportunistic pathogen Candida albicans and reported that the gene deletion had several important physiological consequences. In order to reveal the protein targets and the associated mechanisms behind the functions of the phosphatase a proteomic method was adopted for the comparison of the cappz1 deletion mutant and the genetically matching QMY23 control strain. Proteins extracted from the control and deletion mutant strains were separated by two-dimensional gel electrophoresis and the protein spots were stained with RuBPS and Pro-Q Diamond in order to visualize the total proteome and the phosphoproteome, respectively. The alterations in spot intensities were determined by densitometry and were analysed with the Delta2D (Decodon) software. Spots showing significantly different intensities between the mutant and control strains were excised from the gels and were digested with trypsin. The resulting peptides were identified by LC-MS/MS mass spectrometry. As many as 15 protein spots were found that exhibited significant changes in their intensity upon the deletion of the phosphatase and 20 phosphoproteins were identified in which the level of phosphorylation was modified significantly in the mutant. In agreement with previous findings we found that the affected proteins function in protein synthesis, oxidative stress response, regulation of morphology and metabolism. Among these proteins we identified two potential CaPpz1 substrates (Eft2 and Rpp0) that may regulate the elongation step of translation. RT-qPCR experiments revealed that the expression of the genes coding for the affected proteins was not altered significantly. Thus, the absence of CaPpz1 exerted its effects via protein synthesis/degradation and phosphorylation/dephosphorylation. In addition, our proteomics data strongly suggested a role for

  8. [Inhibitory effects of butyl alcohol extract of Baitouweng decoction on yeast-to-hyphae transition of Candida albicans isolates from VVC in alkaline pH environment].

    Science.gov (United States)

    Zhang, Meng-xiang; Xia, Dan; Shi, Gao-xiang; Shao, Jing; Wang, Tian-ming; Tang, Chuan-chao; Wang, Chang-zhong

    2015-02-01

    To investigate the effects of butyl alcohol extract of Baitouweng decoction ( BAEB) on yeast-to-hyphae transition of Candida albicans isolates from vulvovaginal candidiasis (VVC) in alkaline pH. Serial 2-fold dilution assay was used to determine the minimal inhibitory concentrations (MICs) of Baitouweng decoction extracts against C. albicans isolates from VVC, XTT assay was applied to determine the metabolic activity of C. albicans hypha treated by BAEB for 6 h. The morphological change of C. albicans treated by BAEB was inspected at different pH by inverted microscope, fluorescence microscope, scanning electron microscopy (SEM). Solid agar plate and semi-solid agar were utilized to evaluate colony morphology and invasive growth of C. albicans, respectively. Quantitative Real-time PCR (qRT-PCR) was adopted to observe the expressions of hyphae-specific genes including HWP1, ALS3, CSH1, SUN41 and CaPDE2. The MIC of BAEB against C. albicans is less than that of other extracts; hyphae grow best at pH 8. 0; 512 mg · L(-1) and 1,024 mg · L(-1) BAEB could inhibit formation of hyphae and influence colony morphology. When treated by 512 mg · L(-1) and 1,024 mg · L(-1) BAEB, the colonies became smooth; while by 0 and 256 mg · L(-1) BAEB, the colonies became wrinkled. In semi-solid agar, the length of hyphae decreased steadily as the concentration of BAEB lowered. The expression of HWP1, ALS3, CSHl, SUN41 were downregulated by 5.12, 4.26, 3.2 and 2.74 folds, and CaPDE2 was upregulated by 2.38 fold. BAEB could inhibit yeast-to-hyphae transition of C. albicans isolates from VVC in alkaline pH.

  9. Candida albicans biofilms and MMA surface treatment influence the adhesion of soft denture liners to PMMA resin

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    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.

  10. Identification of inhibitors of yeast-to-hyphae transition in Candida albicans by a reporter screening assay.

    Science.gov (United States)

    Heintz-Buschart, Anna; Eickhoff, Holger; Hohn, Erwin; Bilitewski, Ursula

    2013-03-10

    Candida albicans is one of the most common opportunistic fungal pathogens, causing life-threatening disease in immunocompromised patients. As it is not primarily a pathogen, but can exist in a commensal state, we aimed at the identification of new anti-infective compounds which do not eradicate the fungus, but primarily disable a virulence determinant. The yeast–hyphae-dimorphism of C. albicans is considered a major contributor to fungal disease, as mutants locked into either yeast or hyphal state have been shown to be less virulent in the mouse-model. We devised a high-throughput screening procedure which allows us to find inhibitors of the induction of hyphae. Hyphae-formation was induced by nitrogen starvation at 37 °C and neutral pH in a reporter strain, which couples promoter activity of the hyphae-specific HWP1 to β-galactosidase expression. In a pilot screening of 720 novel synthetic compounds, we identified substances which inhibited the outgrowth of germ tubes. They belonged to chemical classes not yet known for antimycotic properties, namely methyl aryl-oxazoline carboxylates, dihydrobenzo[d]isoxazolones and thiazolo[4,5-e]benzoisoxazoles. In conclusion we developed a novel screening assay, which addresses the morphological switch from the yeast form of C. albicans to its hyphal form and identified novel chemical structures with activity against C. albicans. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. RT-PCR detection of Candida albicans ALS gene expression in the reconstituted human epithelium (RHE) model of oral candidiasis and in model biofilms.

    Science.gov (United States)

    Green, Clayton B; Cheng, Georgina; Chandra, Jyotsna; Mukherjee, Pranab; Ghannoum, Mahmoud A; Hoyer, Lois L

    2004-02-01

    An RT-PCR assay was developed to analyse expression patterns of genes in the Candida albicans ALS (agglutinin-like sequence) family. Inoculation of a reconstituted human buccal epithelium (RHE) model of mucocutaneous candidiasis with strain SC5314 showed destruction of the epithelial layer by C. albicans and also formation of an upper fungal layer that had characteristics similar to a biofilm. RT-PCR analysis of total RNA samples extracted from C. albicans-inoculated buccal RHE showed that ALS1, ALS2, ALS3, ALS4, ALS5 and ALS9 were consistently detected over time as destruction of the RHE progressed. Detection of transcripts from ALS7, and particularly from ALS6, was more sporadic, but not associated with a strictly temporal pattern. The expression pattern of ALS genes in C. albicans cultures used to inoculate the RHE was similar to that observed in the RHE model, suggesting that contact of C. albicans with buccal RHE does little to alter ALS gene expression. RT-PCR analysis of RNA samples extracted from model denture and catheter biofilms showed similar gene expression patterns to the buccal RHE specimens. Results from the RT-PCR analysis of biofilm RNA specimens were consistent between various C. albicans strains during biofilm development and were comparable to gene expression patterns in planktonic cells. The RT-PCR assay described here will be useful for analysis of human clinical specimens and samples from other disease models. The method will provide further insight into the role of ALS genes and their encoded proteins in the diverse interactions between C. albicans and its host.

  12. Symbiotic Relationship between Streptococcus mutans and Candida albicans Synergizes Virulence of Plaque Biofilms In Vivo

    Science.gov (United States)

    Falsetta, Megan L.; Klein, Marlise I.; Colonne, Punsiri M.; Scott-Anne, Kathleen; Gregoire, Stacy; Pai, Chia-Hua; Gonzalez-Begne, Mireya; Watson, Gene; Krysan, Damian J.; Bowen, William H.

    2014-01-01

    Streptococcus mutans is often cited as the main bacterial pathogen in dental caries, particularly in early-childhood caries (ECC). S. mutans may not act alone; Candida albicans cells are frequently detected along with heavy infection by S. mutans in plaque biofilms from ECC-affected children. It remains to be elucidated whether this association is involved in the enhancement of biofilm virulence. We showed that the ability of these organisms together to form biofilms is enhanced in vitro and in vivo. The presence of C. albicans augments the production of exopolysaccharides (EPS), such that cospecies biofilms accrue more biomass and harbor more viable S. mutans cells than single-species biofilms. The resulting 3-dimensional biofilm architecture displays sizeable S. mutans microcolonies surrounded by fungal cells, which are enmeshed in a dense EPS-rich matrix. Using a rodent model, we explored the implications of this cross-kingdom interaction for the pathogenesis of dental caries. Coinfected animals displayed higher levels of infection and microbial carriage within plaque biofilms than animals infected with either species alone. Furthermore, coinfection synergistically enhanced biofilm virulence, leading to aggressive onset of the disease with rampant carious lesions. Our in vitro data also revealed that glucosyltransferase-derived EPS is a key mediator of cospecies biofilm development and that coexistence with C. albicans induces the expression of virulence genes in S. mutans (e.g., gtfB, fabM). We also found that Candida-derived β1,3-glucans contribute to the EPS matrix structure, while fungal mannan and β-glucan provide sites for GtfB binding and activity. Altogether, we demonstrate a novel mutualistic bacterium-fungus relationship that occurs at a clinically relevant site to amplify the severity of a ubiquitous infectious disease. PMID:24566629

  13. 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.

  14. Determination of chitin content in fungal cell wall: an alternative flow cytometric method.

    Science.gov (United States)

    Costa-de-Oliveira, Sofia; Silva, Ana P; Miranda, Isabel M; Salvador, Alexandre; Azevedo, Maria M; Munro, Carol A; Rodrigues, Acácio G; Pina-Vaz, Cidália

    2013-03-01

    The conventional methods used to evaluate chitin content in fungi, such as biochemical assessment of glucosamine release after acid hydrolysis or epifluorescence microscopy, are low throughput, laborious, time-consuming, and cannot evaluate a large number of cells. We developed a flow cytometric assay, efficient, and fast, based on Calcofluor White staining to measure chitin content in yeast cells. A staining index was defined, its value was directly related to chitin amount and taking into consideration the different levels of autofluorecence. Twenty-two Candida spp. and four Cryptococcus neoformans clinical isolates with distinct susceptibility profiles to caspofungin were evaluated. Candida albicans clinical isolate SC5314, and isogenic strains with deletions in chitin synthase 3 (chs3Δ/chs3Δ) and genes encoding predicted GlycosylPhosphatidylInositol (GPI)-anchored proteins (pga31Δ/Δ and pga62Δ/Δ), were used as controls. As expected, the wild-type strain displayed a significant higher chitin content (P relationship between chitin content and antifungal drug susceptibility phenotype was found, an association was established between the paradoxical growth effect in the presence of high caspofungin concentrations and the chitin content. This novel flow cytometry protocol revealed to be a simple and reliable assay to estimate cell wall chitin content of fungi. Copyright © 2013 International Society for Advancement of Cytometry.

  15. Determination of in vitro oxygen consumption rates for tumor cells

    International Nuclear Information System (INIS)

    Cardenas-Navia, L.I.; Moeller, B.J.; Kirkpatrick, J.P.; Laursen, T.A.; Dewhirst, M.W.

    2003-01-01

    To determine pO 2 at the surface of a monolayer of confluent HCT 116 cells, and to then determine consumption rate in vitro by examining the pO 2 profile in media above the cells. Materials and Methods: A recessed-tip polarographic oxygen microelectrode (diameter ∼10μm) was used to measure pO 2 profiles of media above a confluent monolayer of HCT 116 human colon adenocarcinoma cells in a T25 flask exposed to a 95% air, 5% CO 2 mixture. A two-dimensional finite element analysis of the diffusion equation was used to fit the data, thereby extracting a steady-state O 2 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 O 2 gradient in the media, with a mean (SE) media layer of 1677 (147) μm and a mean pO 2 at the cell layer/media interface of 44 (8) mm Hg (n=9). pO 2 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 O 2 /cm 3 s and 1.0 x 10 3 (0.46 x 10 3 ) /s, respectively. Control experiments in flasks containing no cells show slight gradients in pO 2 of 38 (12) mm Hg/cm, resulting from some O 2 diffusion through the flask into the surrounding water bath. An addition of 10 -3 M NaCN to the media results in a dramatic increase in pO 2 at the cell layer, consistent with a shut-down in respiration. Under normal cell culture conditions there is an O 2 gradient present in the media of cull culture systems, resulting in physiologic O 2 concentrations at the cell layer, despite the non-physiologic O 2 concentration of the gas mixture to which the cell culture system is exposed. This significant (p -6 ) O 2 gradient in the media of cell culture systems is a result of cell O 2

  16. 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

  17. 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).

  18. Collective cell migration without proliferation: density determines cell velocity and wave velocity

    Science.gov (United States)

    Tlili, Sham; Gauquelin, Estelle; Li, Brigitte; Cardoso, Olivier; Ladoux, Benoît; Delanoë-Ayari, Hélène; Graner, François

    2018-05-01

    Collective cell migration contributes to embryogenesis, wound healing and tumour metastasis. Cell monolayer migration experiments help in understanding what determines the movement of cells far from the leading edge. Inhibiting cell proliferation limits cell density increase and prevents jamming; we observe long-duration migration and quantify space-time characteristics of the velocity profile over large length scales and time scales. Velocity waves propagate backwards and their frequency depends only on cell density at the moving front. Both cell average velocity and wave velocity increase linearly with the cell effective radius regardless of the distance to the front. Inhibiting lamellipodia decreases cell velocity while waves either disappear or have a lower frequency. Our model combines conservation laws, monolayer mechanical properties and a phenomenological coupling between strain and polarity: advancing cells pull on their followers, which then become polarized. With reasonable values of parameters, this model agrees with several of our experimental observations. Together, our experiments and model disantangle the respective contributions of active velocity and of proliferation in monolayer migration, explain how cells maintain their polarity far from the moving front, and highlight the importance of strain-polarity coupling and density in long-range information propagation.

  19. Immune response in mice infected with Candida albicans in the mycelial form.

    Science.gov (United States)

    Bibas Bonet de Jorrat, M E; de Valdez, G A; de Petrino, S F; Sirena, A; Perdigón, G

    1989-05-01

    The effect of the infection with the mycelial form of a Candida albicans strain (Mycology Dept.) upon the immune system in mice was studied. BALB/c mice were infected intraperitoneally in a single dose of a 3 x 10(6), 6 x 10(6) and 12 x 10(6) cell suspension of the strain. Macrophages's activity was studied the days 7, 14, 21, 28, 35, and 42 after inoculation, by the following assays: phagocytosis in vitro, mononucleated phagocytic system by the colloidal carbon clearance technique, the lymphocyte's activity by the direct plaque forming cells technique (PFC) and delayed hypersensitivity (DTH). Infection with the mycelial form did not affect the peritoneal macrophage's phagocytic ability, neither modified the delayed hypersensitivity to sheep red blood cells (SRBC). However, a slight and transient depression of the lymphocyte stimulation was found. Suppression of PFC to SRBC was high when a 12 x 10(6) cell suspension was used in contrast to the infection with blastospores. These results suggest that systemic infection by Candida albicans in its mycelial form do not induce a non specific immunosuppression.

  20. 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.

  1. Rsr1 Focuses Cdc42 Activity at Hyphal Tips and Promotes Maintenance of Hyphal Development in Candida albicans

    Science.gov (United States)

    Pulver, Rebecca; Heisel, Timothy; Gonia, Sara; Robins, Robert; Norton, Jennifer; Haynes, Paula

    2013-01-01

    The extremely elongated morphology of fungal hyphae is dependent on the cell's ability to assemble and maintain polarized growth machinery over multiple cell cycles. The different morphologies of the fungus Candida albicans make it an excellent model organism in which to study the spatiotemporal requirements for constitutive polarized growth and the generation of different cell shapes. In C. albicans, deletion of the landmark protein Rsr1 causes defects in morphogenesis that are not predicted from study of the orthologous protein in the related yeast Saccharomyces cerevisiae, thus suggesting that Rsr1 has expanded functions during polarized growth in C. albicans. Here, we show that Rsr1 activity localizes to hyphal tips by the differential localization of the Rsr1 GTPase-activating protein (GAP), Bud2, and guanine nucleotide exchange factor (GEF), Bud5. In addition, we find that Rsr1 is needed to maintain the focused localization of hyphal polarity structures and proteins, including Bem1, a marker of the active GTP-bound form of the Rho GTPase, Cdc42. Further, our results indicate that tip-localized Cdc42 clusters are associated with the cell's ability to express a hyphal transcriptional program and that the ability to generate a focused Cdc42 cluster in early hyphae (germ tubes) is needed to maintain hyphal morphogenesis over time. We propose that in C. albicans, Rsr1 “fine-tunes” the distribution of Cdc42 activity and that self-organizing (Rsr1-independent) mechanisms of polarized growth are not sufficient to generate narrow cell shapes or to provide feedback to the transcriptional program during hyphal morphogenesis. PMID:23223038

  2. Copy number determination of genetically-modified hematopoietic stem cells.

    Science.gov (United States)

    Schuesler, Todd; Reeves, Lilith; Kalle, Christof von; Grassman, Elke

    2009-01-01

    Human gene transfer with gammaretroviral, murine leukemia virus (MLV) based vectors has been shown to effectively insert and express transgene sequences at a level of therapeutic benefit. However, there are numerous reports of disruption of the normal cellular processes caused by the viral insertion, even of replication deficient gammaretroviral vectors. Current gammaretroviral and lentiviral vectors do not control the site of insertion into the genome, hence, the possibility of disruption of the target cell genome. Risk related to viral insertions is linked to the number of insertions of the transgene into the cellular DNA, as has been demonstrated for replication competent and replication deficient retroviruses in experiments. At high number of insertions per cell, cell transformation due to vector induced activation of proto-oncogenes is more likely to occur, in particular since more than one transforming event is needed for oncogenesis. Thus, determination of the vector copy number in bulk transduced populations, individual colony forming units, and tissue from the recipient of the transduced cells is an increasingly important safety assay and has become a standard, though not straightforward assay, since the inception of quantitative PCR.

  3. Cell flux through S phase in the mouse duodenal epithelium determined by cell sorting and radioautography

    International Nuclear Information System (INIS)

    Bjerknes, M.; Cheng, H.

    1982-01-01

    An accumulation of cells in early S phase was observed in normal mouse duodenal epithelium studied with flow cytometry. To determine if this accumulation of cells was the result of a lower rate of DNA synthesis, animals were given a single injection of 3 H-thymidine and the epithelium collected one hour later. The epithelium was processed for flow cytometry. Seven sort windows were established in different portions of the DNA histogram. Cells from each window were sorted onto glass slides that were then processed for radioautography. The number of silver grains over the nuclei of each sorted population was counted. It was found that cells in early S phase had significantly fewer grains over their nuclei than did mid- or late-S phase cells. We conclude that the accumulation of cells in early S phase is due, at least in part, to a lower rate of DNA synthesis in early than in mid or late S phase

  4. The Discovery of a Potential Antimicrobial Agent: the Novel Compound Natural Medicinal Plant Fermentation Extracts against Candida albicans

    Science.gov (United States)

    Song, Mingzhu; Wang, Xirui; Mao, Canquan; Yao, Wei

    2018-01-01

    Natural medicinal plants and their extracts are important sources of antimicrobial drug development. In this study, we reported an ancient formula of Chinese folk medicine, the compound natural medicinal plant fermentation extracts (CNMPFE) for its antimicrobial effects. The effects and mechanisms of CNMPFE on C. albicans were studied by cell damage experiments including antimicrobial kinetics, fungal growth curve, alkaline phosphatase (AKP) activity, ultraviolet absorption, electric conductivity and the evaluation of cellular ultra microstructure. The results showed that the minimal inhibitory concentration and minimum fungicidal concentration of CNMPFE against C. albicans were 75% (vol/vol) and 80% (vol/vol) respectively. The inhibition of CNMPFE for C. albicans was dose and time dependent, based on increasing of the AKP activities and the ultraviolet absorptions and the electric conductivities of the fungal solutions, it may exert its antifungal properties by disrupting the structure of cell wall and the cell membrane integrity and their permeability, subsequently resulting in cell death. Taken together, these findings suggest that CNMPFE may be a promising drug candidate for the treatment of fungal infections skin diseases.

  5. Antimicrobial efficacy of chlorine dioxide against Candida albicans in stationary and starvation phases in human root canal: An in-vitro study

    Directory of Open Access Journals (Sweden)

    Shirur Krishnaraj Somayaji

    2014-01-01

    Full Text Available Introduction: Candida albicans (C. albicans is the most commonly isolated fungal pathogen from dental root canal. C. albicans forms biofilm and develops resistance against root canal irrigants . This study determines the fungicidal efficacy of 13.8% chlorine dioxide in extracted human teeth at stationary and starvation phases of C. albicans. Materials and Methods: Teeth were decoronated and coronal portion of the roots were prepared into blocks, which were incubated at 37°C with C. albicans for five days. The samples were treated with chlorine dioxide for 12 and 20 minutes. Total of fifty blocks were taken in the study. Colony-forming units were counted in Sabourauds dextrose agar and scanning electron microscopic observation was done. Data were analyzed by one-way ANOVA and Bonferoni′s post hoc test. Results: Teeth at stationary phase (12 min showed mean colony count of 28,000 ± 1814 which is significantly (P < 0.001 less than control group. Teeth at starvation phase (12 min showed colony count of 65,600 ± 1912 which is also significantly (P < 0.001 less than control group. Teeth irrigated at stationary phase (20 min showed mean colony count of 23,400 ± 1776 (P < 0.001. Teeth irrigated at starvation phase (20 min showed mean colony count of 48,100 ± 1663 which is also significantly (P < 0.001 less than that of control group. Conclusion: Treatment of chlorine dioxide reduces the C. albicans count in root canals of extracted human teeth at stationary and starvation phases. Efficacy of chlorine dioxide against C. albicans is relatively higher in stationary phase than that of starvation phase.

  6. 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.

  7. Rutas de glicosilación en Candida albicans: circuitos reguladores y efectos sobre virulencia

    OpenAIRE

    Domínguez Cantero, María del Pilar

    2011-01-01

    [ES]Esta tesis trata sobre las rutas de glicosilación en Candida albicans: circuitos reguladores y efectos sobre virulencia. [EN]This thesis is about glycosylation pathways in Candida albicans: regulatory circuits and effects on virulence.

  8. In vitro effects of glycyrrhetinic acid and hyaluronic acid on the growth of vulvovaginal Candida albicans and other yeasts

    Directory of Open Access Journals (Sweden)

    Martina Stevan

    2017-12-01

    Full Text Available Aims. The present study aimed to test the in vitro activity against Candida albicans and non-albicans strains of 18-β glycyrrhetinic acid (18-β GA and hyaluronic acid (HA, both alone and in combination. This antimicrobial activity was assessed using the National Committee for Clinical Laboratory Standards (NCCLS method on Candida strains that were isolated from patients with recurrent vulvovaginal candidiasis (RVVC. Results. Our results demonstrate that the anti-Candida activity is independent from antifungal susceptibility level and the fact that the growth inhibition is stronger at acidic pH level makes the two drugs a promising biological alternative for the topical treatment of vulvovaginal candidiasis (VVC and RVVC. Conclusions. Furthermore, the reduction of both budding cells formation and germ tube elongation, on mammalian cell monolayers, may explain the observed growth inhibition and suggest a decreased virulence, respectively.

  9. Mitochondrial pyruvate carrier function determines cell stemness and metabolic reprogramming in cancer cells

    Science.gov (United States)

    Li, Xiaoran; Kan, Quancheng; Fan, Zhirui; Li, Yaqing; Ji, Yasai; Zhao, Jing; Zhang, Mingzhi; Grigalavicius, Mantas; Berge, Viktor; Goscinski, Mariusz Adam; M. Nesland, Jahn; Suo, Zhenhe

    2017-01-01

    One of the remarkable features of cancer cells is aerobic glycolysis, a phenomenon known as the “Warburg Effect”, in which cells rely preferentially on glycolysis instead of oxidative phosphorylation (OXPHOS) as the main energy source even in the presence of high oxygen tension. Cells with dysfunctional mitochondria are unable to generate sufficient ATP from mitochondrial OXPHOS, and then are forced to rely on glycolysis for ATP generation. Here we report our results in a prostate cancer cell line in which the mitochondrial pyruvate carrier 1 (MPC1) gene was knockout. It was discovered that the MPC1 gene knockout cells revealed a metabolism reprogramming to aerobic glycolysis with reduced ATP production, and the cells became more migratory and resistant to both chemotherapy and radiotherapy. In addition, the MPC1 knockout cells expressed significantly higher levels of the stemness markers Nanog, Hif1α, Notch1, CD44 and ALDH. To further verify the correlation of MPC gene function and cell stemness/metabolic reprogramming, MPC inhibitor UK5099 was applied in two ovarian cancer cell lines and similar results were obtained. Taken together, our results reveal that functional MPC may determine the fate of metabolic program and the stemness status of cancer cells in vitro. PMID:28624784

  10. Operating Cell Temperature Determination in Flat-Plate Photovoltaic Modules

    International Nuclear Information System (INIS)

    Chenlo, F.

    2002-01-01

    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

  11. The neural stem cell fate determinant TLX promotes tumorigenesis and genesis of cells resembling glioma stem cells.

    Science.gov (United States)

    Park, Hyo-Jung; Kim, Jun-Kyum; Jeon, Hye-Min; Oh, Se-Yeong; Kim, Sung-Hak; Nam, Do-Hyun; Kim, Hyunggee

    2010-11-01

    A growing body of evidence indicates that deregulation of stem cell fate determinants is a hallmark of many types of malignancies. The neural stem cell fate determinant TLX plays a pivotal role in neurogenesis in the adult brain by maintaining neural stem cells. Here, we report a tumorigenic role of TLX in brain tumor initiation and progression. Increased TLX expression was observed in a number of glioma cells and glioma stem cells, and correlated with poor survival of patients with gliomas. Ectopic expression of TLX in the U87MG glioma cell line and Ink4a/Arf-deficient mouse astrocytes (Ink4a/Arf(-/-) astrocytes) induced cell proliferation with a concomitant increase in cyclin D expression, and accelerated foci formation in soft agar and tumor formation in in vivo transplantation assays. Furthermore, overexpression of TLX in Ink4a/Arf(-/-) astrocytes inhibited cell migration and invasion and promoted neurosphere formation and Nestin expression, which are hallmark characteristics of glioma stem cells, under stem cell culture conditions. Our results indicate that TLX is involved in glioma stem cell genesis and represents a potential therapeutic target for this type of malignancy.

  12. Cell cycle phase of nondividing cells in aging human cell cultures determined by DNA content and chromosomal constitution

    International Nuclear Information System (INIS)

    Yanishevsky, R.M.

    1975-01-01

    Human diploid cell cultures, strain WI-38, have a finite proliferative capacity and have been proposed as a model of biological aging. To identify the cell cycle phase of the nondividing cells, cultures of various ages were exposed to 3 Hdt for 48 hours to label dividing cells, then the cycle phase was identified for individual cells by one of two methods, and finally, the proliferative status of the same cells was scored by autoradiographic evidence of 3 HdT uptake. The methods to identify the cycle phase were: determination of DNA strain content by Feulgen scanning cytophotometry, and determination of chromosome constitution by the technique of premature chromosome condensation (PCC). Preliminary experiments showed the effect of continuous exposure to various levels of 3 HdT on cell growth. High levels of 3 HdT inhibited cell cycle traverse: the cell number and labeling index curves reached a plateau; the cell volume increased; the cells accumulated with 4C DNA contents and it appeared that they blocked in G 2 phase. This pattern is consistent with a radiation effect. (U.S.)

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

    Science.gov (United States)

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

    1995-09-01

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

  14. Pathogenesis of Candida albicans infections in the alternative chorio-allantoic membrane chicken embryo model resembles systemic murine infections.

    Directory of Open Access Journals (Sweden)

    Ilse D Jacobsen

    Full Text Available 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 response, characterized by lower induction of proinflammatory cytokines and increased transcription of regulatory cytokines, suggesting that immunopathology contributes to pathogenesis. While many aspects of the chicken embryo response resembled murine infections, we also observed significant differences: In contrast to systemic infections in mice, IL-10 had a beneficial effect in chicken embryos. IL-22 and IL-17A were only upregulated after the peak mortality in the chicken embryo model occurred; thus, the role of the Th17 response in this model remains unclear. Abscess formation occurs frequently in murine models, whereas the avian response was dominated by granuloma formation. Pathogenicity of the majority of 15 tested C. albicans deletion strains was comparable to the virulence in mouse models and reduced virulence was associated with significantly lower transcription of proinflammatory cytokines. However, fungal burden did not correlate with virulence and for few mutants like bcr1Δ and tec1Δ different outcomes in survival compared to murine infections were observed. C. albicans strains locked in the yeast stage disseminated significantly more often from the CAM into the embryo, supporting the hypothesis that the yeast morphology is responsible for dissemination in systemic infections. These data suggest that the pathogenesis of C. albicans infections in the chicken embryo model resembles systemic murine infections but also differs in some aspects. Despite

  15. Antiadherent activity of Schinus terebinthifolius and Croton urucurana extracts on in vitro biofilm formation of Candida albicans and Streptococcus mutans.

    Science.gov (United States)

    Barbieri, Dicler S V; Tonial, Fabiana; Lopez, Patricia V A; Sales Maia, Beatriz H L N; Santos, Germana D; Ribas, Marina O; Glienke, Chirlei; Vicente, Vania A

    2014-09-01

    To evaluate the antiadherent property of crude, methanol and acetate methanol extract fractions from Schinus terebinthifolius and Croton urucurana in hydroalcoholic (HA) and dimethylsulfoxide (DMSO) solvents on in vitro biofilms formed by Streptococcus mutans and Candida albicans strains. The minimal concentration of adherence (MICA) was determined to evaluate the antiadherent potential of extracts on the in vitro biofilm formation. The extracts of plants were subjected to thin layer chromatography (TLC) in order to detect what class of compounds was responsible for the antiadherent activity. Data were estimated by analysis of variance (ANOVA) complemented by Tukey test level of significance set at 5%. Both plants demonstrated inhibition of S. mutans and C. albicans on in vitro biofilm formation. The biofilms of C. albicans were more efficiently inhibited by the S. terebinthifolius fraction of acetate-methanol and methanol in hydroalcoholic solvents (p<0.05). The S. mutans biofilms adherence was best inhibited by the S. terebinthifolius crude extract and its methanolic fraction, both in hydroalcoholic solvent (p<0.05). TLC of crude extracts and fractions of S. terebinthifolius detected the presence of several active compounds, including phenolic compounds, anthraquinones, terpenoids, and alkaloids. C. urucurana extracts confirmed activity for both microorganisms (p<0.05). However, higher concentrations were needed to achieve antiadherent activity, mainly to inhibit in vitro biofilm formation of C. albicans. The antiadherent potential of both plants on in vitro biofilms formed by C. albicans and S. mutans were confirmed, suggesting the importance of studies about these extracts for therapeutic prevention of oral diseases associated with oral biofilms. Copyright © 2014. Published by Elsevier Ltd.

  16. Monocyte-mediated Serum-independent Damage to Hyphal and Pseudohyphal Forms of Candida albicans In Vitro

    OpenAIRE

    Diamond, Richard D.; Haudenschild, Christian C.

    1981-01-01

    Human peripheral blood monocytes attached to Candida albicans hyphae in the absence of serum and damaged the hyphae without completely ingesting them. Attachment and damage was not augmented by the addition of serum. Damage to hyphae was quantitated by a previously developed metabolic assay that measured leukocyte-induced reduction in uptake of [14C]cytosine by the hyphae. Use of cells from patients with hereditary disorders of leukocyte function, chronic granulomatous disease, and myeloperox...

  17. 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

  18. Irreversible electropermeabilization of the human pathogen Candida albicans: an in-vitro experimental study.

    Science.gov (United States)

    Novickij, Vitalij; Grainys, Audrius; Svediene, Jurgita; Markovskaja, Svetlana; Paskevicius, Algimantas; Novickij, Jurij

    2015-02-01

    Pathogenic fungi cause many life-threatening infections, especially among individuals with immune system dysfunction. The antifungal drugs commonly used to suppress fungal pathogens can result in long-lasting and toxic therapy. In this work, irreversible electropermeabilization was used to investigate the dynamics of the decrease in Candida albicans colony vitality after application of a pulsed electric field (PEF) and use of antifungal drugs. The fungi were subjected to single 250-µs to 2-ms (0.5-2.5 kV/cm) pulses or repeated short 5-µs pulses, and efficacy was compared. It was shown that electropermeabilization combined with antifungal agents results in rapid and more effective treatment, eliminating more than 90% of C. albicans colony-forming units in a single procedure, which is advantageous in biomedicine. It was also observed that, because of application of PEF and use of the antifungal agents, the Candida cells form cell aggregates and average live cell size is reduced by as much as 53%.

  19. IL-1 Coordinates the Neutrophil Response to C. albicans in the Oral Mucosa.

    Directory of Open Access Journals (Sweden)

    Simon Altmeier

    2016-09-01

    Full Text Available Mucosal infections with Candida albicans belong to the most frequent forms of fungal diseases. Host protection is conferred by cellular immunity; however, the induction of antifungal immunity is not well understood. Using a mouse model of oropharyngeal candidiasis (OPC we show that interleukin-1 receptor (IL-1R signaling is critical for fungal control at the onset of infection through its impact on neutrophils at two levels. We demonstrate that both the recruitment of circulating neutrophils to the site of infection and the mobilization of newly generated neutrophils from the bone marrow depended on IL-1R. Consistently, IL-1R-deficient mice displayed impaired chemokine production at the site of infection and defective secretion of granulocyte colony-stimulating factor (G-CSF in the circulation in response to C. albicans. Strikingly, endothelial cells were identified as the primary cellular source of G-CSF during OPC, which responded to IL-1α that was released from keratinocytes in the infected tissue. The IL-1-dependent crosstalk between two different cellular subsets of the nonhematopoietic compartment was confirmed in vitro using a novel murine tongue-derived keratinocyte cell line and an established endothelial cell line. These data establish a new link between IL-1 and granulopoiesis in the context of fungal infection. Together, we identified two complementary mechanisms coordinating the neutrophil response in the oral mucosa, which is critical for preventing fungal growth and dissemination, and thus protects the host from disease.

  20. IL-1 Coordinates the Neutrophil Response to C. albicans in the Oral Mucosa.

    Science.gov (United States)

    Altmeier, Simon; Toska, Albulena; Sparber, Florian; Teijeira, Alvaro; Halin, Cornelia; LeibundGut-Landmann, Salomé

    2016-09-01

    Mucosal infections with Candida albicans belong to the most frequent forms of fungal diseases. Host protection is conferred by cellular immunity; however, the induction of antifungal immunity is not well understood. Using a mouse model of oropharyngeal candidiasis (OPC) we show that interleukin-1 receptor (IL-1R) signaling is critical for fungal control at the onset of infection through its impact on neutrophils at two levels. We demonstrate that both the recruitment of circulating neutrophils to the site of infection and the mobilization of newly generated neutrophils from the bone marrow depended on IL-1R. Consistently, IL-1R-deficient mice displayed impaired chemokine production at the site of infection and defective secretion of granulocyte colony-stimulating factor (G-CSF) in the circulation in response to C. albicans. Strikingly, endothelial cells were identified as the primary cellular source of G-CSF during OPC, which responded to IL-1α that was released from keratinocytes in the infected tissue. The IL-1-dependent crosstalk between two different cellular subsets of the nonhematopoietic compartment was confirmed in vitro using a novel murine tongue-derived keratinocyte cell line and an established endothelial cell line. These data establish a new link between IL-1 and granulopoiesis in the context of fungal infection. Together, we identified two complementary mechanisms coordinating the neutrophil response in the oral mucosa, which is critical for preventing fungal growth and dissemination, and thus protects the host from disease.

  1. 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. © 2015 Blackwell Verlag GmbH.

  2. Role of Notch signaling in cell-fate determination of human mammary stem/progenitor cells

    International Nuclear Information System (INIS)

    Dontu, Gabriela; Jackson, Kyle W; McNicholas, Erin; Kawamura, Mari J; Abdallah, Wissam M; Wicha, Max S

    2004-01-01

    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

  3. A radiolabel release microassay for phagocytic killing of Candida albicans

    International Nuclear Information System (INIS)

    Bistoni, F.; Baccarini, M.; Blasi, E.; Marconi, P.; Puccetti, P.

    1982-01-01

    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.)

  4. The dectin-1/inflammasome pathway is responsible for the induction of protective T-helper 17 responses that discriminate between yeasts and hyphae of Candida albicans.

    Science.gov (United States)

    Cheng, Shih-Chin; van de Veerdonk, Frank L; Lenardon, Megan; Stoffels, Monique; Plantinga, Theo; Smeekens, Sanne; Rizzetto, Lisa; Mukaremera, Liliane; Preechasuth, Kanya; Cavalieri, Duccio; Kanneganti, Thirumala Devi; van der Meer, Jos W M; Kullberg, Bart Jan; Joosten, Leo A B; Gow, Neil A R; Netea, Mihai G

    2011-08-01

    In the mucosa, the immune pathways discriminating between colonizing and invasive Candida, thus inducing tolerance or inflammation, are poorly understood. Th17 responses induced by Candida albicans hyphae are central for the activation of mucosal antifungal immunity. An essential step for the discrimination between yeasts and hyphae and induction of Th17 responses is the activation of the inflammasome by C. albicans hyphae and the subsequent release of active IL-1β in macrophages. Inflammasome activation in macrophages results from differences in cell-wall architecture between yeasts and hyphae and is partly mediated by the dectin-1/Syk pathway. These results define the dectin-1/inflammasome pathway as the mechanism that enables the host immune system to mount a protective Th17 response and distinguish between colonization and tissue invasion by C. albicans.

  5. 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.

  6. Determinants of academic performance in children with sickle cell anaemia.

    Science.gov (United States)

    Ezenwosu, Osita U; Emodi, Ifeoma J; Ikefuna, Anthony N; Chukwu, Barth F; Osuorah, Chidiebere D

    2013-11-19

    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. 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- matched normal classmates were recruited as controls. The total number of days of school absence for 2009/2010 academic session was obtained for each pair of pupils from the class attendance register. Academic performance was assessed using the average of the overall scores in the three term examinations of same session. Intelligence ability was determined with Draw-A-Person Quotient (DAPQ) using the Draw-A-Person Test while socio-economic status was determined using the occupational status and educational attainment of each parent. Academic performance of children with SCA showed statistically significant association with their socio-economic status (χ2 = 9.626, p = 0.047), and significant correlation with DAPQ (r = 0.394, p = 0.000) and age (r = -0.412, p = 0.000). However, no significant relationship existed between academic performance and school absence in children with SCA (r = -0.080, p = 0.453). Academic performance of children with SCA is influenced by their intelligence ability, age and socio-economic status but not negatively affected by their increased school absenteeism.

  7. Study of the prevalence and association of ocular chlamydial conjunctivitis in women with genital infection by Chlamydia trachomatis, Mycoplasma genitalium and Candida albicans attending outpatient clinic.

    Science.gov (United States)

    Khattab, Rania Abdelmonem; Abdelfattah, Maha Mohssen

    2016-01-01

    To determine the association between chlamydial conjunctivitis and genital infection by Chlamydia trachomatis, Mycoplasma genitalium and Candida albicans, in addition to the possible relationship between cultured bacterial pathogens and oculogenital chlamydial infection. This study was performed on 100 (50 symptomatic and 50 asymptomatic) women attending the Gynecological and Obstetric outpatient clinic of Alzahra hospital, Alazhar University. Simultaneously a conjunctival swab was taken from these patients. Polymerase chain reaction (PCR) was done on DNA extracted from both vaginal and conjunctival swab samples. Culture for both vaginal and conjunctival swabs was also done. Candida albicans was the predominant organism isolated by culture in 20% and 40% of conjunctival and vaginal swabs respectively. By the PCR method, ocular Chlamydia trachomatis was present in 60% of symptomatic women, while genital Chlamydia trachomatis infection was present in 30% of symptomatic women. The results of this method also indicated that 25/50 (50%) vaginal swabs were positive with PCR for Candida albicans versus 15/50 (30%) were PCR positive in conjunctival swab. Mycoplasma genitalium was present in only 10% of vaginal swabs. Concomitant oculogenital PCR positive results for Chlamydia trachomatis and Candida albicans were 30% and 28% respectively. Ocular Chlamydia trachomatis was associated with genital Chlamydia trachomatis in a high percentage of women followed by Candida albicans. Cultured bacterial organisms do not play a role in enhancement of Chlamydia trachomatis infection.

  8. Quercetin Assists Fluconazole to Inhibit Biofilm Formations of Fluconazole-Resistant Candida Albicans in In Vitro and In Vivo Antifungal Managements of Vulvovaginal Candidiasis

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    Mei Gao

    2016-11-01

    Full Text Available Background: Vulvovaginal candidiasis (VVC is a common gynecological disease. Candida albicans is believed to be mainly implicated in VVC occurrence, the biofilm of which is one of the virulence factors responsible for resistance to traditional antifungal agents especially to fluconazole (FCZ. Quercetin (QCT is a dietary flavonoid and has been demonstrated to be antifungal against C. albicans biofilm. Methods: 17 C. albicans isolates including 15 clinical ones isolated from VVC patients were employed to investigate the effects of QCT and/or FCZ on the inhibition of C. albicans biofilm. Results: We observed that 64 µg/mL QCT and/or 128 µg/mL FCZ could (i be synergistic against 10 FCZ-resistant planktonic and 17 biofilm cells of C. albicans, (ii inhibit fungal adherence, cell surface hydrophobicity (CSH, flocculation, yeast-to-hypha transition, metabolism, thickness and dispersion of biofilms; (iii down-regulate the expressions of ALS1, ALS3, HWP1, SUN41, UME6 and ECE1 and up-regulate the expressions of PDE2, NRG1 and HSP90, and we also found that (iv the fungal burden was reduced in vaginal mucosa and the symptoms were alleviated in a murine VVC model after the treatments of 5 mg/kg QCT and/or 20 mg/kg FCZ. Conclusion: Together with these results, it could be demonstrated that QCT could be a favorable antifungal agent and a promising synergist with FCZ in the clinical management of VVC caused by C. albicans biofilm.

  9. Effects of 60 Cobalt ionizing radiation in morphology and metabolism of yeasts and Chlamydospore of Candida albicans

    International Nuclear Information System (INIS)

    Grillo, Michel R.F.; Demicheli, Marina C.; Andrade Junior, Heitor F.; Galiesteo Junior, Andres A.J.

    2015-01-01

    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 ( 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)

  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. Determination of residual cell culture media components by MEKC.

    Science.gov (United States)

    Zhang, Junge; Chakraborty, Utpal; Foley, Joe P

    2009-11-01

    Folic acid, hypoxanthine, mycophenolic acid, nicotinic acid, riboflavin, and xanthine are widely used as cell culture media components in monoclonal antibody manufacturing. These components are subsequently removed during the downstream purification processes. This article describes a single MEKC method that can simultaneously determine all the listed compounds with acceptable LOD and LOQ. All the analytes were successfully separated by MEKC using running buffer containing 40 mM SDS, 20 mM sodium phosphate, and 20 mM sodium borate at pH 9.0. The MEKC method was compared to the corresponding CZE method using the same running buffer containing no SDS. The effect of SDS concentration on separation, the pH of the running buffer, and the detection wavelength were studied and optimal MEKC conditions were established. Good linearity was obtained with correlation coefficients of more than 0.99 for all analytes. Specificity, accuracy, and precision were also evaluated. The recovery was in the range of 89-112%. The precision results were in the range of 1.7-4.8%. The experimentally determined data demonstrated that the MEKC method is applicable to the determination of the six analytes in in-process samples from monoclonal antibody manufacturing processes.

  12. Antifungal activity of components used for decontamination of dental prostheses on the growth of Candida albicans

    Directory of Open Access Journals (Sweden)

    Cíntia Lima Gouveia

    Full Text Available Introduction: The effectiveness of antimicrobial solutions employed in dental prosthesis decontamination is still uncertain. Aim: To evaluate the antifungal activity of cleaners used in the decontamination of dental prostheses on the growth of Candida albicans. Material and method: The evaluated products were: Corega Tabs(r (S1, Sodium Hypochlorite 1% (S2, Sodium Bicarbonate 1% (S3, Hydrogen Peroxide 1% (S4, Chlorhexidine Digluconate 0.12% - Periogard (r (S5, Mouthrinse based on essential oils - Listerine(r (S6, essential oil from Rosmarinus officinalis (rosemary at concentrations of 1% (S7 and 2% (S8. The antifungal activity of the products was evaluated by agar diffusion technique and the determination of microbial death curve of samples of C. albicans (ATCC 90028 in concentration 1.5 × 106 CFU/mL. The tests were performed in triplicate and statistical analysis was made by ANOVA Two-Way and Tukey tests, with the confidence level of 95%. Result: The average of the zones of inhibition growth, in millimeters, obtained for the products were: 0.0 (S1, 44.7 (S2, 0.0 (S3, 21.6 (S4, 10.0 (S5, 6.1 (S6, 0.0 (S7 and 2.4 (S8. Considering the determination of microbial death curve, all products showed a statistical difference (p<0.01 from control (0.85% sodium chloride and S3 groups. Fungal growth less than 2×104 CFU/mL and an accentuation of the microbial death curve were observed after 30 minutes, with exception for S3 and control groups. Conclusion: The studied compounds, with the exception of Sodium Bicarbonate, have antifungal effect against C. albicans, which contribute for dental prostheses hygiene.

  13. Effect of the Ethyl Acetate Fraction of Eugenia uniflora on Proteins Global Expression during Morphogenesis in Candida albicans

    Directory of Open Access Journals (Sweden)

    Walicyranison P. Silva-Rocha

    2017-09-01

    Full Text Available Candida albicans is able to switch from yeast to hyphal growth and this is an essential step for tissue invasion and establishment of infection. Due to the limited drug arsenal used to treat fungal infections and the constant emergence of resistant strains, it is important to search for new therapeutic candidates. Therefore, this study aimed to investigate by proteomic analysis the role of a natural product (Eugenia uniflora in impairing hypha formation in C. albicans. We also tested the potential action of E. uniflora to prevent and treat oral candidiasis induced in a murine model of oral infection and the ability of polymorphonuclear neutrophils to phagocytize C. albicans cells treated with the ethyl acetate fraction of the extract. We found that this fraction greatly reduced hypha formation after morphogenesis induction in the presence of serum. Besides, several proteins were differentially expressed in cells treated with the fraction. Surprisingly, the ethyl acetate fraction significantly reduced phagocytosis in C. albicans (Mean 120.36 ± 36.71 yeasts/100 PMNs vs. 44.68 ± 19.84 yeasts/100 PMNs. Oral candidiasis was attenuated when C. albicans cells were either pre-incubated in the presence of E. uniflora or when the fraction was applied to the surface of the oral cavity after infection. These results were consistent with the reduction in CFU counts (2.36 vs. 1.85 Log10 CFU/ml and attenuation of tissue damage observed with histopathological analysis of animals belonging to treated group. We also observed shorter true hyphae by direct examination and histopathological analysis, when cells were treated with the referred natural product. The E. uniflora ethyl acetate fraction was non-toxic to human cells. E. uniflora may act on essential proteins mainly related to cellular structure, reducing the capacity of filamentation and attenuating infection in a murine model, without causing any toxic effect on human cells, suggesting that it may be a

  14. Aberrant lipogenesis is a metabolic marker for azole-resistant candida albicans (Conference Presentation)

    Science.gov (United States)

    Karanja, Caroline; Hong, Weili; Younis, Waleed; Cheng, Ji-Xin; Seleem, Mohamed

    2017-02-01

    Candida is the single most important cause of fungal bloodstream infections worldwide causing significant mortality as high as 50%. This high mortality rate is, in part, due to the inability to rapidly diagnose and simultaneously initiate an effective antifungal therapy early in the disease process. Current culture-based diagnostics are often slow, requiring several days to complete, and are only 50% sensitive in diagnosing candidemia (Candida bloodstream infection). For every 12 hours of delay in starting correct antifungal therapy, the risk of death for a given patient with candidemia increases by 200%. To address this unmet need, we explored the potential of employing stimulated Raman Scattering (SRS) imaging to diagnose candidemia and probe metabolic differences between resistant and susceptible strain at a single cell level. Metabolism is integral to pathogenicity; microorganism have very short life cycles, and therefore only a few hours are needed to observe a full metabolic cycle. SRS imaging at C-H vibration frequency at 2850 cm-1 revealed a substantial difference in lipogenesis between the susceptible and resistant C. albicans. Treating the C. albicans with fluconazole, an antimicrobial drug that targets ergosterol biosynthesis only affected the lipogenesis in the susceptible strain. Our results show that single-cell metabolic imaging under a SRS microscope can be used for diagnose candidemia and early detection of antimicrobial susceptibility.

  15. Linalool-induced oxidative stress processes in the human pathogen Candida albicans.

    Science.gov (United States)

    Máté, Gábor; Kovács, Dominika; Gazdag, Zoltán; Pesti, Miklós; Szántó, Árpád

    2017-06-01

    The present study investigated the linalool (Lol)-induced effects in acute toxicity tests in the human pathogen Candida albicans (C. albicans). Lol treatments induced reduced germ tube formation of the pathogen, which plays a crucial role in the virulence. In comparison with the untreated control, the exposure of 107 cells ml -1 to 0.7 mM or 1.4 mM Lol for one hour induced 20% and 30% decrements, respectively, in the colony-forming ability. At the same time, these treatments caused dose-dependent decrease in the levels of superoxide anion radical and total reactive oxygen species, while there was 1.5 and 1.8-fold increases in the concentrations of peroxides and lipid peroxides, respectively, indicating oxidative stress induction in the presence of Lol. Lol treatments resulted in different adaptive modifications of the antioxidant system. In 0.7 mM-treated cells, decreased specific activities of superoxide dismutase and catalase were detected, while exposure to 1.4 mM Lol resulted in the up-regulation of catalase, glutathione reductase and glutathione peroxidases.

  16. 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.

  17. Possible mechanisms of the antifungal activity of fluconazole in combination with terbinafine against Candida albicans.

    Science.gov (United States)

    Khodavandi, Alireza; Alizadeh, Fahimeh; Vanda, Nasim Aghai; Karimi, Golgis; Chong, Pei Pei

    2014-12-01

    Candidiasis is a term describing infections by yeasts from the genus Candida, the majority Candida albicans. Treatment of such infections often requires antifungals such as the azoles, but increased use of these drugs has led to selection of yeasts with increased resistance to these drugs. Combination therapy would be one of the best strategies for the treatment of candidiasis due to increased resistance to azoles. The antifungal activities of fluconazole and terbinafine were evaluated in vitro alone and in combination using broth microdilution test and time kill study. Eventually the expression level of selected genes involved in ergosterol biosynthesis of Candida was evaluated using semi-quantitative RT-PCR. The obtained results showed the significant MICs ranging from 0.25 to 8 µg/mL followed by FICs ranged from 0.37 to 1 in combination with fluconazole/terbinafine. Our findings have demonstrated that the combination of fluconazole and terbinafine could also significantly reduce the expression of ERG1, 3, and 11 in the cell membrane of Candida in all concentrations tested ranging from 1.73- to 6.99-fold. This study was undertaken with the ultimate goal of finding the probable targets of fluconazole/terbinafine in C. albicans by looking at its effects on cell membrane synthesis.

  18. An Adaptation to Low Copper in Candida albicans Involving SOD Enzymes and the Alternative Oxidase.

    Directory of Open Access Journals (Sweden)

    Chynna N Broxton

    Full Text Available In eukaryotes, the Cu/Zn superoxide dismutase (SOD1 is a major cytosolic cuproprotein with a small fraction residing in the mitochondrial intermembrane space (IMS to protect against respiratory superoxide. Curiously, the opportunistic human fungal pathogen Candida albicans is predicted to express two cytosolic SODs including Cu/Zn containing SOD1 and manganese containing SOD3. As part of a copper starvation response, C. albicans represses SOD1 and induces the non-copper alternative SOD3. While both SOD1 and SOD3 are predicted to exist in the same cytosolic compartment, their potential role in mitochondrial oxidative stress had yet to be investigated. We show here that under copper replete conditions, a fraction of the Cu/Zn containing SOD1 localizes to the mitochondrial IMS to guard against mitochondrial superoxide. However in copper starved cells, localization of the manganese containing SOD3 is restricted to the cytosol leaving the mitochondrial IMS devoid of SOD. We observe that during copper starvation, an alternative oxidase (AOX form of respiration is induced that is not coupled to ATP synthesis but maintains mitochondrial superoxide at low levels even in the absence of IMS SOD. Surprisingly, the copper-dependent cytochrome c oxidase (COX form of respiration remains high with copper starvation. We provide evidence that repression of SOD1 during copper limitation serves to spare copper for COX and maintain COX respiration. Overall, the complex copper starvation response of C. albicans involving SOD1, SOD3 and AOX minimizes mitochondrial oxidative damage whilst maximizing COX respiration essential for fungal pathogenesis.

  19. 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.

  20. Natural biased coin encoded in the genome determines cell strategy.

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    Faezeh Dorri

    Full Text Available Decision making at a cellular level determines different fates for isogenic cells. However, it is not yet clear how rational decisions are encoded in the genome, how they are transmitted to their offspring, and whether they evolve and become optimized throughout generations. In this paper, we use a game theoretic approach to explain how rational decisions are made in the presence of cooperators and competitors. Our results suggest the existence of an internal switch that operates as a biased coin. The biased coin is, in fact, a biochemical bistable network of interacting genes that can flip to one of its stable states in response to different environmental stimuli. We present a framework to describe how the positions of attractors in such a gene regulatory network correspond to the behavior of a rational player in a competing environment. We evaluate our model by considering lysis/lysogeny decision making of bacteriophage lambda in E. coli.

  1. Quantitative Analyses of Force-Induced Amyloid Formation in Candida albicans Als5p: Activation by Standard Laboratory Procedures.

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    Cho X J Chan

    Full Text Available Candida albicans adhesins have amyloid-forming sequences. In Als5p, these amyloid sequences cluster cell surface adhesins to create high avidity surface adhesion nanodomains. Such nanodomains form after force is applied to the cell surface by atomic force microscopy or laminar flow. Here we report centrifuging and resuspending S. cerevisiae cells expressing Als5p led to 1.7-fold increase in initial rate of adhesion to ligand coated beads. Furthermore, mechanical stress from vortex-mixing of Als5p cells or C. albicans cells also induced additional formation of amyloid nanodomains and consequent activation of adhesion. Vortex-mixing for 60 seconds increased the initial rate of adhesion 1.6-fold. The effects of vortex-mixing were replicated in heat-killed cells as well. Activation was accompanied by increases in thioflavin T cell surface fluorescence measured by flow cytometry or by confocal microscopy. There was no adhesion activation in cells expressing amyloid-impaired Als5pV326N or in cells incubated with inhibitory concentrations of anti-amyloid dyes. Together these results demonstrated the activation of cell surface amyloid nanodomains in yeast expressing Als adhesins, and further delineate the forces that can activate adhesion in vivo. Consequently there is quantitative support for the hypothesis that amyloid forming adhesins act as both force sensors and effectors.