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Sample records for albicans biofilms identification

  1. Identification, Typing, Antifungal Resistance Profile, and Biofilm Formation of Candida albicans Isolates from Lebanese Hospital Patients

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    Ibrahim Bitar

    2014-01-01

    Full Text Available As leading opportunistic fungal pathogens identification and subtyping of Candida species are crucial in recognizing outbreaks of infection, recognizing particularly virulent strains, and detecting the emergence of drug resistant strains. In this study our objective was to compare identification of Candida albicans by the hospitals through the use of conventional versus identification based on the ITS (Internal Transcribed Spacer and to assess biofilm forming capabilities, drug resistance patterns and correlate these with MLST typing. ITS typing revealed a 21.2% hospital misidentification rate. Multidrug resistance to three drugs out of four tested was detected within 25% of the isolates raising concerns about the followed treatment regimens. Drug resistant strains as well as biofilm formers were phylogenetically related, with some isolates with significant biofilm forming capabilities being correlated to those that were multidrug resistant. Such isolates were grouped closely together in a neighbor-joining tree generated by MLST typing indicating phylogenetic relatedness, microevolution, or recurrent infection. In conclusion, this pilot study gives much needed insight concerning C. albicans isolates circulating in Lebanese hospitals and is the first study of its kind correlating biofilm formation, antifungal resistance, and evolutionary relatedness.

  2. Plasticity of Candida albicans Biofilms

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

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    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.

  4. 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.

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

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    Řičicová Markéta

    2010-04-01

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

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

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    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.

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

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    Endang W. Bachtiar

    2014-07-01

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

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

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    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.

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

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    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.

  10. Identification of Genes Upregulated by the Transcription Factor Bcr1 That Are Involved in Impermeability, Impenetrability, and Drug Resistance of Candida albicans a/α Biofilms

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    Srikantha, Thyagarajan; Daniels, Karla J.; Pujol, Claude; Kim, Elena

    2013-01-01

    Candida albicans forms two types of biofilm, depending upon the configuration of the mating type locus. Although architecturally similar, a/α biofilms are impermeable, impenetrable, and drug resistant, whereas a/a and α/α biofilms lack these traits. The difference appears to be the result of an alternative matrix. Overexpression in a/a cells of BCR1, a master regulator of the a/α matrix, conferred impermeability, impenetrability, and drug resistance to a/a biofilms. Deletion of BCR1 in a/α cells resulted in the loss of these a/α-specific biofilm traits. Using BCR1 overexpression in a/a cells, we screened 107 genes of interest and identified 8 that were upregulated by Bcr1. When each was overexpressed in a/a biofilms, the three a/α traits were partially conferred, and when each was deleted in a/α cells, the traits were partially lost. Five of the eight genes have been implicated in iron homeostasis, and six encode proteins that are either in the wall or plasma membrane or secreted. All six possess sites for O-linked and N-linked glycosylation that, like glycosylphosphatidylinositol (GPI) anchors, can cross-link to the wall and matrix, suggesting that they may exert a structural role in conferring impermeability, impenetrability, and drug resistance, in addition to their physiological functions. The fact that in a screen of 107 genes, all 8 of the Bcr1-upregulated genes identified play a role in impermeability, impenetrability, and drug resistance suggests that the formation of the a/α matrix is highly complex and involves a larger number of genes than the initial ones identified here. PMID:23563485

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

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    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.

  12. Evaluation of Candida albicans biofilm formation on various dental ...

    African Journals Online (AJOL)

    Evaluation of Candida albicans biofilm formation on various dental restorative material surfaces. ... Nigerian Journal of Clinical Practice ... was significantly lower on the resin-modified glass ionomer and glass-ionomer cement samples. ... Conclusion: This finding emphasizes the use of glass ionomer restorative cements and ...

  13. 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.

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

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    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.

  15. Biofilm extracellular DNA enhances mixed species biofilms of Staphylococcus epidermidis and Candida albicans.

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    Pammi, Mohan; Liang, Rong; Hicks, John; Mistretta, Toni-Ann; Versalovic, James

    2013-11-14

    Polymicrobial infections are responsible for significant mortality and morbidity in adults and children. Staphylococcus epidermidis and Candida albicans are the most frequent combination of organisms isolated from polymicrobial infections. Vascular indwelling catheters are sites for mixed species biofilm formation and pose a significant risk for polymicrobial infections. We hypothesized that enhancement of biofilms in a mixed species environment increases patient mortality and morbidity. Mixed species biofilms of S. epidermidis and C. albicans were evaluated in vitro and in a subcutaneous catheter infection model in vivo. Mixed species biofilms were enhanced compared to single species biofilms of either S. epidermidis or C. albicans. A mixed species environment increased catheter infection and increased dissemination of S. epidermidis in mice. Microarrays were used to explore differential gene expression of S. epidermidis in the mixed species biofilms. In mixed species biofilms, compared to single species S. epidermidis biofilms, 2.7% of S. epidermidis genes were upregulated and 6% were down regulated. Staphylococcal autolysis repressors lrgA and lrgB were down regulated 36-fold and 27-fold respectively. The role of biofilm extracellular DNA was investigated by quantitation and by evaluating the effects of DNAse in a concentration and time dependent manner. S. epidermidis specific eDNA was increased in mixed species biofilms and further confirmed by degradation with DNAse. Mixed-species biofilms are enhanced and associated with increased S. epidermidis-specific eDNA in vitro and greater systemic dissemination of S. epidermidis in vivo. Down regulation of the lrg operon, a repressor of autolysis, associated with increased eDNA suggests a possible role for bacterial autolysis in mixed species biofilms. Enhancement and systemic dissemination of S. epidermidis may explain adverse outcomes after clinical polymicrobial infections of S. epidermidis and C. albicans.

  16. Biofilm extracellular DNA enhances mixed species biofilms of Staphylococcus epidermidis and Candida albicans

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    2013-01-01

    Background Polymicrobial infections are responsible for significant mortality and morbidity in adults and children. Staphylococcus epidermidis and Candida albicans are the most frequent combination of organisms isolated from polymicrobial infections. Vascular indwelling catheters are sites for mixed species biofilm formation and pose a significant risk for polymicrobial infections. We hypothesized that enhancement of biofilms in a mixed species environment increases patient mortality and morbidity. Results Mixed species biofilms of S. epidermidis and C. albicans were evaluated in vitro and in a subcutaneous catheter infection model in vivo. Mixed species biofilms were enhanced compared to single species biofilms of either S. epidermidis or C. albicans. A mixed species environment increased catheter infection and increased dissemination of S. epidermidis in mice. Microarrays were used to explore differential gene expression of S. epidermidis in the mixed species biofilms. In mixed species biofilms, compared to single species S. epidermidis biofilms, 2.7% of S. epidermidis genes were upregulated and 6% were down regulated. Staphylococcal autolysis repressors lrgA and lrgB were down regulated 36-fold and 27-fold respectively. The role of biofilm extracellular DNA was investigated by quantitation and by evaluating the effects of DNAse in a concentration and time dependent manner. S. epidermidis specific eDNA was increased in mixed species biofilms and further confirmed by degradation with DNAse. Conclusions Mixed-species biofilms are enhanced and associated with increased S. epidermidis-specific eDNA in vitro and greater systemic dissemination of S. epidermidis in vivo. Down regulation of the lrg operon, a repressor of autolysis, associated with increased eDNA suggests a possible role for bacterial autolysis in mixed species biofilms. Enhancement and systemic dissemination of S. epidermidis may explain adverse outcomes after clinical polymicrobial infections of S

  17. Candida albicans biofilm development in vitro for photodynamic therapy study

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    Suzuki, Luis Claudio

    2009-01-01

    Photodynamic therapy (PDT) is a phototherapy based on the use of a photo sensitizer (PS) in the presence of low intensity light with resonant wavelength of absorption of the PS and biological systems that can raise awareness, generating reactive oxygen species. Studies show that PDT has a lethal effect on Candida albicans. The biofilm formed by C. albicans is the cause of infections associated with medical devices such as catheters, with a proven resistance to antifungal agents, and the removal of the catheter colonized almost always is necessary. However, few studies in literature report the behavior and response of biofilm organized by C. albicans against PDT. The aims of this study were to develop a methodology for in vitro biofilm formation of C. albicans, evaluate the sensitivity of the biofilm of C. albicans to antimicrobial photodynamic therapy using PS as the methylene blue (MB) and hypocrellin B: La +3 (HBL a+3 ) and analyze the biofilm by Optical Coherence Tomography (OCT). For biofilm formation, discs were made from elastomeric silicone catheters. The PS were dissolved in solution of PBS, and the MB had two different concentrations tested in the biofilm: 100μM and 1mM; HBLa +3 only one of 10μM. The irradiation of both dyes with the microorganism was done by two different LEDs, one with red emission at λ = 630nm ± 20nm and the other one blue emission at λ = 460nm ± 30nm. We performed a curve of survival fraction versus time of irradiation of each sample with biofilm and suspension of the microorganism in the yeast form to verify the susceptibility of the front PDT. The yeast showed 100% reduction using both PS, but at different times of irradiation (30s to HBLa +3 and 6 min for the MB at 100μM). When the therapy was applied in biofilm, the MB 100μM did not show any significant reduction, while at concentration of 1mM was reduced by 100% after 6 min of irradiation. The HBLa +3 biofilm group showed a lower reduction in the concentration of 10μM in

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

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    Apurva K Pathak

    2012-02-01

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

  19. 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

  20. 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.

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

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    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

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

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    Mohamed Ahariz

    2010-08-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  4. The effect of Streptococcus mutans and Candida glabrata on Candida albicans biofilms formed on different surfaces

    NARCIS (Netherlands)

    Pereira-Cenci, T.; Deng, D.M.; Kraneveld, E.A.; Manders, E.M.M.; Del Bel Cury, A.A.; ten Cate, J.M.; Crielaard, W.

    2008-01-01

    Although Candida containing biofilms contribute to the development of oral candidosis, the characteristics of multi-species Candida biofilms and how oral bacteria modulate these biofilms is poorly understood. The aim of this study was to investigate interactions between Candida albicans and either

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2016-01-01

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

  8. Cranberry-derived proanthocyanidins prevent formation of Candida albicans biofilms in artificial urine through biofilm- and adherence-specific mechanisms.

    Science.gov (United States)

    Rane, Hallie S; Bernardo, Stella M; Howell, Amy B; Lee, Samuel A

    2014-02-01

    Candida albicans is a common cause of nosocomial urinary tract infections (UTIs) and is responsible for increased morbidity and healthcare costs. Moreover, the US Centers for Medicare & Medicaid Services no longer reimburse for hospital-acquired catheter-associated UTIs. Thus, development of specific approaches for the prevention of Candida urinary infections is needed. Cranberry juice-derived proanthocyanidins (PACs) have efficacy in the prevention of bacterial UTIs, partially due to anti-adherence properties, but there are limited data on their use for the prevention and/or treatment of Candida UTIs. Therefore, we sought to systematically assess the in vitro effect of cranberry-derived PACs on C. albicans biofilm formation in artificial urine. C. albicans biofilms in artificial urine were coincubated with cranberry PACs at serially increasing concentrations and biofilm metabolic activity was assessed using the XTT assay in static microplate and silicone disc models. Cranberry PAC concentrations of ≥16 mg/L significantly reduced biofilm formation in all C. albicans strains tested, with a paradoxical effect observed at high concentrations in two clinical isolates. Further, cranberry PACs were additive in combination with traditional antifungals. Cranberry PACs reduced C. albicans adherence to both polystyrene and silicone. Supplementation of the medium with iron reduced the efficacy of cranberry PACs against biofilms. These findings indicate that cranberry PACs have excellent in vitro activity against C. albicans biofilm formation in artificial urine. We present preliminary evidence that cranberry PAC activity against C. albicans biofilm formation is due to anti-adherence properties and/or iron chelation.

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

    Science.gov (United States)

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

    2016-09-01

    Neutrophils release extracellular traps (NETs) in response to planktonic C. albicans. These complexes composed of DNA, histones, and proteins inhibit Candida growth and dissemination. Considering the resilience of Candida biofilms to host defenses, we examined the neutrophil response to C. albicans during biofilm growth. In contrast to planktonic C. albicans, biofilms triggered negligible release of NETs. Time lapse imaging confirmed the impairment in NET release and revealed neutrophils adhering to hyphae and migrating on the biofilm. NET inhibition depended on an intact extracellular biofilm matrix as physical or genetic disruption of this component resulted in NET release. Biofilm inhibition of NETosis could not be overcome by protein kinase C activation via phorbol myristate acetate (PMA) and was associated with suppression of neutrophil reactive oxygen species (ROS) production. The degree of impaired NET release correlated with resistance to neutrophil attack. The clinical relevance of the role for extracellular matrix in diminishing NET production was corroborated in vivo using a rat catheter model. The C. albicans pmr1Δ/Δ, defective in production of matrix mannan, appeared to elicit a greater abundance of NETs by scanning electron microscopy imaging, which correlated with a decreased fungal burden. Together, these findings show that C. albicans biofilms impair neutrophil response through an inhibitory pathway induced by the extracellular matrix.

  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. Influence of culture conditions for clinically isolated non-albicans Candida biofilm formation.

    Science.gov (United States)

    Tan, Yulong; Leonhard, Matthias; Ma, Su; Schneider-Stickler, Berit

    2016-11-01

    Non-albicans Candida species have been isolated in increasing numbers in patients. Moreover, they are adept at forming biofilms. This study analyzed biofilm formation of clinically isolated non-albicans Candida, including Candida tropicalis, Candida krusei and Candida parapsilosis under the influence of different growth media (RPMI 1640, YPD and BHI) and several culture variables (inoculum concentration, incubation period and feeding conditions). The results showed that culture conditions strongly influenced non-albicans Candida species biofilm formation. YPD and BHI resulted in larger amount of biofilm formation with higher metabolic activity of biofilms. Furthermore, the growth media seems to have varying effects on adhesion and biofilm development. Growth conditions may also influence biofilm formation, which was enhanced when starting the culture with a larger inoculum, longer incubation period and using a fed-batch system. Therefore, the potential influences of external environmental factors should be considered when studying the non-albicans Candida biofilms in vitro. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. 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.

  13. 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

  14. 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.

  15. Silver colloidal nanoparticles: effect on matrix composition and structure of Candida albicans and Candida glabrata biofilms.

    Science.gov (United States)

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

    2013-04-01

    The aim of this study was to assess the effect of different silver nanoparticles (SN) concentrations on the matrix composition and structure of Candida albicans and Candida glabrata biofilms. Candida biofilms were developed in 6-well microtiter plates during 48 h. After, these biofilms were exposed to 13.5 or 54 μg SN ml(-1) for 24 h. Then, extracellular matrices were extracted from biofilms and analysed chemically in terms of proteins, carbohydrates and DNA. To investigate the biofilm structure, scanning electron microscopy (SEM) and epifluorescence microscopy were used. SN interfered with the matrix composition of Candida biofilms tested in terms of protein, carbohydrate and DNA, except for the protein content of C. albicans biofilm. By SEM, Candida biofilms treated with SN revealed structural differences, when compared with the control groups. Further, SN showed a trend of agglomeration within the biofilms. Epifluorescence microscopy images suggest that SN induced damage on cell walls of the Candida isolates tested. In general, irrespective of concentration, SN affected the matrix composition and structure of Candida biofilms and these findings may be related to the mechanisms of biocide action of SN. This study reveals new insights about the behaviour of SN when in contact with Candida biofilms. SN may contribute to the development of therapies to prevent or control Candida infections. © 2012 The Society for Applied Microbiology.

  16. 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.

  17. 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

  18. 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.

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

    Science.gov (United States)

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

    2014-08-01

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

  20. Levorotatory carbohydrates and xylitol subdue Streptococcus mutans and Candida albicans adhesion and biofilm formation.

    Science.gov (United States)

    Brambilla, Eugenio; Ionescu, Andrei C; Cazzaniga, Gloria; Ottobelli, Marco; Samaranayake, Lakshman P

    2016-05-01

    Dietary carbohydrates and polyols affect the microbial colonization of oral surfaces by modulating adhesion and biofilm formation. The aim of this study was to evaluate the influence of a select group of l-carbohydrates and polyols on either Streptococcus mutans or Candida albicans adhesion and biofilm formation in vitro. S. mutans or C. albicans suspensions were inoculated on polystyrene substrata in the presence of Tryptic soy broth containing 5% of the following compounds: d-glucose, d-mannose, l-glucose, l-mannose, d- and l-glucose (raceme), d- and l-mannose (raceme), l-glucose and l-mannose, sorbitol, mannitol, and xylitol. Microbial adhesion (2 h) and biofilm formation (24 h) were evaluated using MTT-test and Scanning Electron Microscopy (SEM). Xylitol and l-carbohydrates induced the lowest adhesion and biofilm formation in both the tested species, while sorbitol and mannitol did not promote C. albicans biofilm formation. Higher adhesion and biofilm formation was noted in both organisms in the presence of d-carbohydrates relative to their l-carbohydrate counterparts. These results elucidate, hitherto undescribed, interactions of the individually tested strains with l- and d-carbohydrates, and how they impact fungal and bacterial colonization. In translational terms, our data raise the possibility of using l-form of carbohydrates and xylitol for dietary control of oral plaque biofilms. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. 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.

  2. 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.

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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.

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

    Science.gov (United States)

    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.

  7. 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

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. 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:.

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

    Directory of Open Access Journals (Sweden)

    Anna Murzyn

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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  20. 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.

  1. Propolis Is an Efficient Fungicide and Inhibitor of Biofilm Production by Vaginal Candida albicans

    Directory of Open Access Journals (Sweden)

    Isis Regina Grenier Capoci

    2015-01-01

    Full Text Available Vulvovaginal candidiasis (VVC is one of the most common genital infections in women. The therapeutic arsenal remains restricted, and some alternatives to VVC treatment are being studied. The present study evaluated the influence of a propolis extractive solution (PES on biofilm production by Candida albicans isolated from patients with VVC. Susceptibility testing was used to verify the minimum inhibitory concentration (MIC of PES, with fluconazole and nystatin as controls. The biofilm formation of 29 vaginal isolates of C. albicans and a reference strain that were exposed to PES was evaluated using crystal violet staining. Colony-forming units were evaluated, proteins and carbohydrates of the matrix biofilm were quantified, and scanning electron microscopy was performed. The MIC of PES ranged from 68.35 to 546.87 μg/mL of total phenol content in gallic acid. A concentration of 546.87 μg/mL was able to cause the death of 75.8% of the isolates. PES inhibited biofilm formation by C. albicans from VVC. Besides antifungal activity, PES appears to present important antibiofilm activity on abiotic surfaces, indicating that it may have an additional beneficial effect in the treatment of VVC.

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

    African Journals Online (AJOL)

    2018-02-07

    Feb 7, 2018 ... Aims: Candida albicans adhesion to any oral substrata is the first and essential stage in forming a .... kinds of resin, glass, and even metal surfaces.[14] ... various parts of implant materials [tissue level implant, bone level ...

  3. Assessing the potential of four cathelicidins for the management of mouse candidiasis and Candida albicans biofilms.

    Science.gov (United States)

    Yu, Haining; Liu, Xuelian; Wang, Chen; Qiao, Xue; Wu, Sijin; Wang, Hui; Feng, Lan; Wang, Yipeng

    2016-02-01

    As the most common fungal pathogen of humans, severe drug resistance has emerged in the clinically isolated Candida albicans, which lead to the urgency to develop novel antifungal agents. Here, four our previously characterized cathelicidins (cathelicidin-BF, Pc-CATH1, Cc-CATH2, Cc-CATH3) were selected and their antifungal activities against C. albicans were evaluated in vitro and in vivo using amphotericin B and LL-37 as control. Results showed that all four cathelicidins could eradicate standard and clinically isolated C. albicans strains with most MIC values ranging from 1 to 16 μg/ml, in less than 0.5 h revealed by time-kill kinetic assay. Four peptides only exhibited slight hemolytic activity with most HC50 > 200 μg/ml, and retained potent anti-C. albicans activity at salt concentrations below and beyond physiological level. In animal experiment, 50 mg/kg administration of the four cathelicidins could significantly reduce the fungal counts in a murine oral candidiasis model induced by clinically isolated C. albicans. The antibiofilm activity of cathelicidin-BF, the most potent among the five peptides was evaluated, and result showed that cathelicidin-BF strongly inhibited C. albicans biofilm formation at 20 μg/ml. Furthermore, cathelicidin-BF also exhibited potent anti-C. albicans activity in established biofilms as measured by metabolic and fluorescent viability assays. Structure-function analyses suggest that they mainly adopt an α-helical conformations, which enable them to act as a membrane-active molecule. Altogether, the four cathelicidins display great potential for antifungal agent development against candidiasis. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  4. 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

  5. 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

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

    Science.gov (United States)

    2013-11-07

    RESEARCH ARTICLE Open Access C. albicans growth, transition, biofilm formation, and gene expression modulation by antimicrobial decapeptide KSL-W...at the end of the article © 2013 Theberge et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the...microbial growth and plaque formation by surfactant drugs. J Periodontal Res 1978, 13:474–485. 36. Semlali A, Leung KP, Curt S, Rouabhia M

  8. Effect of Candida albicans and Candida dubliniensis planktonic/biofilm quorum sensing molecules on yeast morphogenesis

    OpenAIRE

    Henriques, Mariana; Martins, Margarida Isabel Barros Coelho; Azeredo, Joana; Oliveira, Rosário

    2006-01-01

    One of the aims of this work was to study the effect of farnesol, a quorum sensing molecule for Candida albicans, on morphologic inhibition of Candida dubliniensis. The second goal of this work was to confirm if Candida dubliniensis also excreted quorum sensing molecules, on both planktonic and biofilm forms. The results clearly demonstrate that Candida dubliniensis undergoes morphological alterations triggered by farnesol. It was also found that supernatants of Candida dubliniensis and Ca...

  9. Flexible camphor diamond-like carbon coating on polyurethane to prevent Candida albicans biofilm growth.

    Science.gov (United States)

    Santos, Thaisa B; Vieira, Angela A; Paula, Luciana O; Santos, Everton D; Radi, Polyana A; Khouri, Sônia; Maciel, Homero S; Pessoa, Rodrigo S; Vieira, Lucia

    2017-04-01

    Camphor was incorporated in diamond-like carbon (DLC) films to prevent the Candida albicans yeasts fouling on polyurethane substrates, which is a material commonly used for catheter manufacturing. The camphor:DLC and DLC film for this investigation was produced by plasma enhanced chemical vapor deposition (PECVD), using an apparatus based on the flash evaporation of organic liquid (hexane) containing diluted camphor for camphor:DLC and hexane/methane, mixture for DLC films. The film was deposited at a low temperature of less than 25°C. We obtained very adherent camphor:DLC and DLC films that accompanied the substrate flexibility without delamination. The adherence of camphor:DLC and DLC films on polyurethane segments were evaluated by scratching test and bending polyurethane segments at 180°. The polyurethane samples, with and without camphor:DLC and DLC films were characterized by Raman spectroscopy, scanning electron microscopy, atomic force microscopy, and optical profilometry. Candida albicans biofilm formation on polyurethane, with and without camphor:DLC and DLC, was assessed. The camphor:DLC and DLC films reduced the biofilm growth by 99.0% and 91.0% of Candida albicans, respectively, compared to bare polyurethane. These results open the doors to studies of functionalized DLC coatings with biofilm inhibition properties used in the production of catheters or other biomedical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    V. F. Furletti

    2011-01-01

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

  12. Interactions between Candida albicans and Candida glabrata in biofilms: Influence of the strain type, culture medium and glucose supplementation.

    Science.gov (United States)

    Hosida, Thayse Yumi; Cavazana, Thamires Priscila; Henriques, Mariana; Pessan, Juliano Pelim; Delbem, Alberto Carlos Botazzo; Monteiro, Douglas Roberto

    2018-04-01

    The relationship among Candida species may be influenced by several factors. Thus, this study evaluated the interactions between Candida albicans and Candida glabrata in biofilms, varying the strain type, culture medium and glucose supplementation. Biofilms were formed for 48 hours in Sabouraud dextrose broth (SDB) or RPMI 1640, supplemented with 0%, 1% or 5% glucose. Each strain of C. albicans was combined with two strains of C. glabrata, generating four biofilm associations, which were quantified by colony-forming units (CFUs), total biomass and metabolic activity. Data were analysed by ANOVA and Tukey's HSD test (α = 0.05). For CFUs, all associations were classified as indifferent for biofilms formed in RPMI 1640, while for SDB the interactions were antagonistic for C. albicans and indifferent for C. glabrata. The association of reference strains resulted in a dual-species biofilm with biomass significantly higher than that observed for each single biofilm developed in SDB. The metabolic activity of dual-species biofilms did not significantly differ from that found for single ones, except for co-culture of the reference strains. Glucose supplementation and culture media had a significant influence on all parameters. In conclusion, the strain type, culture medium and glucose supplementation influenced the interactions between C. albicans and C. glabrata. © 2017 Blackwell Verlag GmbH.

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

    Science.gov (United States)

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

    2011-11-01

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

  14. The effect of propolis honey candy on C. Albicans and clinical isolate biofilms viability (in-vitro)

    Science.gov (United States)

    Soekanto, Sri Angky; Bachtiar, Endang W.; Ramadhan, Amatul Firdaus; Febrina, Riri; Sahlan, Muhamad

    2018-02-01

    The objective of this study was to analyze the effectiveness of Propolis honey candy on the formation of C. Albicans ATCC 10231 and Clinical Isolate biofilms. C. Albicans ATCC 10231 and Clinical Isolate were cultured on 96-wellplates that were previously coated with saliva and serum on each well plate. On each group, a solution of Propolis honey candy, X candy, and honey candy was distributed with a 50% concentration of solution. The well plates were then tested using MTT assay. For the X Candy, both C. Albicans ATCC 10231 and Clinical Isolate biofilms that were coated with saliva and serum showed a significant increase of biofilm formation (0.669±0.320) compared to the control (0.223±0.138). However, there were no significant differences between Propolis honey candy (0.171±0.120) and honey candy (0.217±0.112) in the formation of C. Albicans ATCC 10231 and Clinical Isolate biofilms compared to control. Propolis honey candy has a tendency to decrease the formation of C. Albicans ATCC 10231 and Clinical Isolate biofilms.

  15. 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.

  16. 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.

  17. 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.

  18. Proteus vulgaris and Proteus mirabilis Decrease Candida albicans Biofilm Formation by Suppressing Morphological Transition to Its Hyphal Form.

    Science.gov (United States)

    Lee, Kyoung Ho; Park, Su Jung; Choi, Sun Ju; Park, Joo Young

    2017-11-01

    Candida albicans (C. albicans) and Proteus species are causative agents in a variety of opportunistic nosocomial infections, and their ability to form biofilms is known to be a virulence factor. In this study, the influence of co-cultivation with Proteus vulgaris (P. vulgaris) and Proteus mirabilis (P. mirabilis) on C. albicans biofilm formation and its underlying mechanisms were examined. XTT reduction assays were adopted to measure biofilm formation, and viable colony counts were performed to quantify yeast growth. Real-time reverse transcriptase polymerase chain reaction was used to evaluate the expression of yeast-specific genes (rhd1 and rbe1), filament formation inhibiting genes (tup1 and nrg1), and hyphae-related genes (als3, ece1, hwp1, and sap5). Candida biofilm formation was markedly inhibited by treatment with either living or heat-killed P. vulgaris and P. mirabilis. Proteus-cultured supernatant also inhibited Candida biofilm formation. Likewise, treatment with live P. vulgaris or P. mirabilis or with Proteus-cultured supernatant decreased expression of hyphae-related C. albicans genes, while the expression of yeast-specific genes and the filament formation inhibiting genes of C. albicans were increased. Heat-killed P. vulgaris and P. mirabilis treatment, however, did not affect the expression of C. albicans morphology-related genes. These results suggest that secretory products from P. vulgaris and P. mirabilis regulate the expression of genes related to morphologic changes in C. albicans such that transition from the yeast form to the hyphal form can be inhibited. © Copyright: Yonsei University College of Medicine 2017

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

    Science.gov (United States)

    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. 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

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

    Directory of Open Access Journals (Sweden)

    Martinna de Mendonça e Bertolini

    2014-01-01

    Full Text Available The effect of Candida albicans biofilms and methyl methacrylate (MMA pretreatment on the bond strength between soft denture liners and polymethyl methacrylate (PMMA resin was analyzed. Specimens were prepared and randomly divided with respect to PMMA pretreatment, soft liner type (silicone-based or PMMA-based, and presence or absence of a C. albicans biofilm. Samples were composed of a soft denture liner bonded between two PMMA bars. Specimens (n = 10 were incubated to produce a C. albicans biofilm or stored in sterile PBS for 12 days. The tensile bond strength test was performed and failure type was determined using a stereomicroscope. Surface roughness (SR and scanning electron microscopy (SEM analysis were performed on denture liners (n = 8. Highest bond strength was observed in samples containing a silicone-based soft liner and stored in PBS, regardless of pretreatment (p < 0.01. Silicone-based specimens mostly underwent adhesive failures, while samples containing PMMA-based liners predominantly underwent cohesive failures. The silicone-based specimens SR decreased after 12 days of biofilm accumulation or PBS storage, while the SR of PMMA-based soft liners increased (p < 0.01. The PMMA-based soft liners surfaces presented sharp valleys and depressions, while silicone-based specimens surfaces exhibited more gentle features. In vitro exposure to C. albicans biofilms reduced the adhesion of denture liners to PMMA resin, and MMA pretreatment is recommended during relining procedures.

  2. Penicillenols from a deep-sea fungus Aspergillus restrictus inhibit Candida albicans biofilm formation and hyphal growth.

    Science.gov (United States)

    Wang, Jie; Yao, Qi-Feng; Amin, Muhammad; Nong, Xu-Hua; Zhang, Xiao-Yong; Qi, Shu-Hua

    2017-06-01

    Penicillenols (A1, A2, B1, B2, C1 and C2) were isolated from Aspergillus restrictus DFFSCS006, and could differentially inhibit biofilm formation and eradicate pre-developed biofilms of Candida albicans. Their structure-bioactivity relationships suggested that the saturation of hydrocarbon chain at C-8, R-configuration of C-5 and trans-configuration of the double bond between C-5 and C-6 of pyrrolidine-2,4-dione unit were important for their anti-biofilm activities. Penicillenols A2 and B1 slowed the hyphal growth and suppressed the transcripts of hypha specific genes HWP1, ALS1, ALS3, ECE1 and SAP4. Moreover, penicillenols A2 and B1 were found to act synergistically with amphotericin B against C. albicans biofilm formation.

  3. Efficacy of citric acid denture cleanser on the Candida albicans biofilm formed on poly(methyl methacrylate): effects on residual biofilm and recolonization process.

    Science.gov (United States)

    Faot, Fernanda; Cavalcanti, Yuri Wanderley; Mendonça e Bertolini, Martinna de; Pinto, Luciana de Rezende; da Silva, Wander José; Cury, Altair Antoninha Del Bel

    2014-06-23

    It is well known that the use of denture cleansers can reduce Candida albicans biofilm accumulation; however, the efficacy of citric acid denture cleansers is uncertain. In addition, the long-term efficacy of this denture cleanser is not well established, and their effect on residual biofilms is unknown. This in vitro study evaluated the efficacy of citric acid denture cleanser treatment on C. albicans biofilm recolonization on poly(methyl methacrylate) (PMMA) surface. C. albicans biofilms were developed for 72 h on PMMA resin specimens (n = 168), which were randomly assigned to 1 of 3 cleansing treatments (CTs) overnight (8 h). CTs included purified water as a control (CTC) and two experimental groups that used either a 1:5 dilution of citric acid denture cleanser (CT5) or a 1:8 dilution of citric acid denture cleanser (CT8). Residual biofilms adhering to the specimens were collected and quantified at two time points: immediately after CTs (ICT) and after cleaning and residual biofilm recolonization (RT). Residual biofilms were analyzed by quantifying the viable cells (CFU/mL), and biofilm architecture was evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Denture cleanser treatments and evaluation periods were considered study factors. Data were analyzed using two-way ANOVA and Tukey's Honestly Significant Difference (HSD) test (α = 0.05). Immediately after treatments, citric acid denture cleansing solutions (CT5 and CT8) reduced the number of viable cells as compared with the control (p recolonization (p recolonization was also detected by CLSM and SEM analysis, which revealed a higher biomass and average biofilm thickness for the CT8 group (p recolonization.

  4. Evaluation of CAMP-Like Effect, Biofilm Formation, and Discrimination of Candida africana from Vaginal Candida albicans Species

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    Keyvan Pakshir

    2017-01-01

    Full Text Available Candida africana as a species recovered from female genital specimens is highly close to C. albicans. The present study was conducted to discriminate C. africana from presumptive vaginal C. albicans strains by molecular assay and evaluate their hemolysin activity, biofilm formation, and cohemolytic effect (CAMP with vaginal bacterial flora. A total of 110 stock vaginal C. albicans isolates were examined by HWP1 gene amplification. Hemolysin activity and the ability of biofilm formation were evaluated by blood plate assay and visual detection methods, respectively. Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus agalactiae were used to evaluate the CAMP-like effects in Sabouraud blood agar media. Based on the size of the amplicons (941 bp, all isolates were identified as C. albicans. All samples were able to produce beta-hemolysin. Moreover, 69 out of 110 of the isolates (62.7% were biofilm-positive, 54 out of 110 Candida isolates (49% demonstrated cohemolytic effects with S. agalactiae, and 48 out of 110 showed this effect with S. aureus (43.6%. All isolates were CAMP-negative with S. epidermidis. We detected all isolates as Candida albicans and almost half of the isolates were CAMP-positive with S. aureus and S. agalactiae, suggesting that these bacteria increase the pathogenicity of Candida in vaginal candidiasis.

  5. Evaluation of CAMP-Like Effect, Biofilm Formation, and Discrimination of Candida africana from Vaginal Candida albicans Species

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    Bordbar, Mahboubeh; Nouraei, Hasti; Khodadadi, Hossein

    2017-01-01

    Candida africana as a species recovered from female genital specimens is highly close to C. albicans. The present study was conducted to discriminate C. africana from presumptive vaginal C. albicans strains by molecular assay and evaluate their hemolysin activity, biofilm formation, and cohemolytic effect (CAMP) with vaginal bacterial flora. A total of 110 stock vaginal C. albicans isolates were examined by HWP1 gene amplification. Hemolysin activity and the ability of biofilm formation were evaluated by blood plate assay and visual detection methods, respectively. Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus agalactiae were used to evaluate the CAMP-like effects in Sabouraud blood agar media. Based on the size of the amplicons (941 bp), all isolates were identified as C. albicans. All samples were able to produce beta-hemolysin. Moreover, 69 out of 110 of the isolates (62.7%) were biofilm-positive, 54 out of 110 Candida isolates (49%) demonstrated cohemolytic effects with S. agalactiae, and 48 out of 110 showed this effect with S. aureus (43.6%). All isolates were CAMP-negative with S. epidermidis. We detected all isolates as Candida albicans and almost half of the isolates were CAMP-positive with S. aureus and S. agalactiae, suggesting that these bacteria increase the pathogenicity of Candida in vaginal candidiasis. PMID:29318048

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

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    Michelle Peneluppi Silva

    2012-02-01

    Full Text Available Due to the increase in life expectancy, new treatments have emerged which, although palliative, provide individuals with a better quality of life. Artificial saliva is a solution that contains substances that moisten a dry mouth, thus mimicking the role of saliva in lubricating the oral cavity and controlling the existing normal oral microbiota. This study aimed to assess the influence of commercially available artificial saliva on biofilm formation by Candida albicans. Artificial saliva I consists of carboxymethylcellulose, while artificial saliva II is composed of glucose oxidase, lactoferrin, lysozyme and lactoperoxidase. A control group used sterile distilled water. Microorganisms from the oral cavity were transferred to Sabouraud Dextrose Agar and incubated at 37°C for 24 hours. Colonies of Candida albicans were suspended in a sterile solution of NaCl 0.9%, and standardisation of the suspension to 106 cells/mL was achieved. The acrylic discs, immersed in artificial saliva and sterile distilled water, were placed in a 24-well plate containing 2 mL of Sabouraud Dextrose Broth plus 5% sucrose and 0.1 mL aliquot of the Candida albicans suspension. The plates were incubated at 37°C for 5 days, the discs were washed in 2 mL of 0.9% NaCl and placed into a tube containing 10 mL of 0.9% NaCl. After decimal dilutions, aliquots of 0.1 mL were seeded on Sabouraud Dextrose Agar and incubated at 37°C for 48 hours. Counts were reported as CFU/mL (Log10. A statistically significant reduction of 29.89% (1.45 CFU/mL of Candida albicans was observed in saliva I when compared to saliva II (p = 0.002, considering p≤0.05.

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

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    Shahla Roudbarmohammadi

    2016-01-01

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

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

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

    2014-01-01

    Polymicrobial biofilms are of large medical importance, but relatively little is known about the role of interspecies interactions for their physiology and virulence. Here, we studied two human pathogens co-occuring in the oral cavity, the opportunistic fungus Candida albicans and the caries-promoting bacterium Streptococcus mutans. Dual-species biofilms reached higher biomass and cell numbers than mono-species biofilms, and the production of extracellular polymeric substances (EPSs) by S. mutans was strongly suppressed, which was confirmed by scanning electron microscopy, gas chromatography–mass spectrometry and transcriptome analysis. To detect interkingdom communication, C. albicans was co-cultivated with a strain of S. mutans carrying a transcriptional fusion between a green fluorescent protein-encoding gene and the promoter for sigX, the alternative sigma factor of S. mutans, which is induced by quorum sensing signals. Strong induction of sigX was observed in dual-species biofilms, but not in single-species biofilms. Conditioned media from mixed biofilms but not from C. albicans or S. mutans cultivated alone activated sigX in the reporter strain. Deletion of comS encoding the synthesis of the sigX-inducing peptide precursor abolished this activity, whereas deletion of comC encoding the competence-stimulating peptide precursor had no effect. Transcriptome analysis of S. mutans confirmed induction of comS, sigX, bacteriocins and the downstream late competence genes, including fratricins, in dual-species biofilms. We show here for the first time the stimulation of the complete quorum sensing system of S. mutans by a species from another kingdom, namely the fungus C. albicans, resulting in fundamentally changed virulence properties of the caries pathogen. PMID:24824668

  9. The Anti-Adhesive Effect of Curcumin on Candida albicans Biofilms on Denture Materials

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    Gordon Ramage

    2017-04-01

    Full Text Available The use of natural compounds as an alternative source of antimicrobials has become a necessity given the growing concern over global antimicrobial resistance. Polyphenols, found in various edible plants, offers one potential solution to this. We aimed to investigate the possibility of using curcumin within the context of oral health as a way of inhibiting and preventing the harmful development of Candida albicans biofilms. We undertook a series of adsorption experiments with varying concentrations of curcumin, showing that 50 μg/ml could prevent adhesion. This effect could be further synergized by the curcumin pre-treatment of yeast cells to obtain significantly greater inhibition (>90%, p < 0.001. Investigation of the biological impact of curcumin showed that it preferentially affected immature morphological forms (yeast and germlings, and actively promoted aggregation of the cells. Transcriptional analyses showed that key adhesins were down-regulated (ALS1 and ALS3, whereas aggregation related genes (ALS5 and AAF1 were up-regulated. Collectively, these data demonstrated that curcumin elicits anti-adhesive effects and that induces transcription of genes integrally involved in the processes related to biofilm formation. Curcumin and associated polyphenols therefore have the capacity to be developed for use in oral healthcare to augment existing preventative strategies for candidal biofilms on the denture surface.

  10. Real-time evaluation of two light delivery systems for photodynamic disinfection of Candida albicans biofilm in curved root canals.

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    Sabino, C P; Garcez, A S; Núñez, S C; Ribeiro, M S; Hamblin, M R

    2015-08-01

    Antimicrobial photodynamic therapy (APDT) combined with endodontic treatment has been recognized as an alternative approach to complement conventional root canal disinfection methods on bacterial biofilms. We developed an in  vitro model of bioluminescent Candida albicans biofilm inside curved dental root canals and investigated the microbial reduction produced when different light delivery methods are employed. Each light delivery method was evaluated in respect to the light distribution provided inside curved root canals. After conventional endodontic preparation, teeth were sterilized before canals were contaminated by a bioluminescent strain of C. albicans (CEC789). Methylene blue (90 μM) was introduced into the canals and then irradiated (λ = 660 nm, P = 100 mW, beam diameter = 2 mm) with laser tip either in contact with pulp chamber or within the canal using an optical diffuser fiber. Light distribution was evaluated by CCD camera, and microbial reduction was monitored through bioluminescence imaging. Our findings demonstrated that the bioluminescent C. albicans biofilm model had good reproducibility and uniformity. Light distribution in dental tissue was markedly dependent on the light delivery system, and this strategy was directly related to microbial destruction. Both light delivery systems performed significant fungal inactivation. However, when irradiation was performed with optical diffuser fiber, microbial burden reduction was nearly 100 times more effective. Bioluminescence is an interesting real-time analysis to endodontic C. albicans biofilm inactivation. APDT showed to be an effective way to inactivate C. albicans biofilms. Diffuser fibers provided optimized light distribution inside curved root canals and significantly increased APDT efficiency.

  11. An in vitro Model for Oral Mixed Biofilms of Candida albicans and Streptococcus gordonii in Synthetic Saliva

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    Daniel eMontelongo-Jauregui

    2016-05-01

    Full Text Available As a member of the normal human oral microbiota, the fungus C. albicans is often found in association with Streptococcus gordonii, a member of dental plaque forming bacteria. Evidence suggests that S. gordonii serves as a facilitator of C. albicans adherence to dental tissues, which represents a clinically relevant problem, particularly for immunocompromised individuals that could subsequently develop fungal infections. In this study we describe the development of a relatively simple and economical in vitro model that allows for the growth of mixed bacterial/fungal biofilms in 96-well microtiter plates. We have applied this method to test and compare the growth characteristics of single and dual species biofilms in traditional microbiological media versus a synthetic saliva medium (basal medium mucin, BMM that more closely resembles physiological conditions within the oral cavity. Results indicated a synergistic effect for the formation of biofilms when both microorganisms were seeded together under all conditions tested. The structural and architectural features of the resulting biofilms were further characterized using scanning electron microscopy (SEM and confocal scanning laser microscopy (CSLM. We also performed drug susceptibility assays against single and mixed species biofilms using commonly used antifungals and antibacterial antibiotics, both in monotherapy and in combination therapy, for a direct comparison of resistance against antimicrobial treatment. As expected, mixed species biofilms displayed higher levels of resistance to antimicrobial treatment at every dose tested in both traditional media and BMM synthetic saliva, as compared to single-species biofilms.

  12. The Effect of Essential Oils and Bioactive Fractions on Streptococcus mutans and Candida albicans Biofilms: A Confocal Analysis

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    Irlan Almeida Freires

    2015-01-01

    Full Text Available The essential oils (EO and bioactive fractions (BF from Aloysia gratissima, Baccharis dracunculifolia, Coriandrum sativum, Cyperus articulatus, and Lippia sidoides were proven to have strong antimicrobial activity on planktonic microorganisms; however, little is known about their effects on the morphology or viability of oral biofilms. Previously, we determined the EO/fractions with the best antimicrobial activity against Streptococcus mutans and Candida spp. In this report, we used a confocal analysis to investigate the effect of these EO and BF on the morphology of S. mutans biofilms (thickness, biovolume, and architecture and on the metabolic viability of C. albicans biofilms. The analysis of intact treated S. mutans biofilms showed no statistical difference for thickness in all groups compared to the control. However, a significant reduction in the biovolume of extracellular polysaccharides and bacteria was observed for A. gratissima and L. sidoides groups, indicating that these BF disrupt biofilm integrity and may have created porosity in the biofilm. This phenomenon could potentially result in a weakened structure and affect biofilm dynamics. Finally, C. sativum EO drastically affected C. albicans viability when compared to the control. These results highlight the promising antimicrobial activity of these plant species and support future translational research on the treatment of dental caries and oral candidiasis.

  13. Effect of tt-farnesol and myricetin on in vitro biofilm formed by Streptococcus mutans and Candida albicans.

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    Rocha, Guilherme Roncari; Florez Salamanca, Elkin Jahir; de Barros, Ana Letícia; Lobo, Carmélia Isabel Vitorino; Klein, Marlise Inêz

    2018-02-14

    Dental caries is considered a multifactorial disease, in which microorganisms play an important role. The diet is decisive in the biofilm formation because it provides the necessary resources for cellular growth and exopolysaccharides synthesis. Exopolysaccharides are the main components of the extracellular matrix (ECM). The ECM provides a 3D structure, support for the microorganisms and form diffusion-limited environments (acidic niches) that cause demineralization of the dental enamel. Streptococcus mutans is the main producer of exopolysaccharides. Candida albicans is detected together with S. mutans in biofilms associated with severe caries lesions. Thus, this study aimed to determine the effect of tt-farnesol and myricetin topical treatments on cariogenic biofilms formed by Streptococcus mutans and Candida albicans. In vitro dual-species biofilms were grown on saliva-coated hydroxyapatite discs, using tryptone-yeast extract broth with 1% sucrose (37 °C, 5% CO 2 ). Twice-daily topical treatments were performed with: vehicle (ethanol 15%, negative control), 2 mM myricetin, 4 mM tt-farnesol, myricetin + tt-farnesol, myricetin + tt-farnesol + fluoride (250 ppm), fluoride, and chlorhexidine digluconate (0.12%; positive control). After 67 h, biofilms were evaluated to determine biofilm biomass, microbial population, and water-soluble and -insoluble exopolysaccharides in the ECM. Only the positive control yielded a reduced quantity of biomass and microbial population, while tt-farnesol treatment was the least efficient in reducing C. albicans population. The combination therapy myricetin + farnesol + fluoride significantly reduced water-soluble exopolysaccharides in the ECM (vs. negative control; p < 0.05; ANOVA one-way, followed by Tukey's test), similarly to the positive control. Therefore, the combination therapy negatively influenced an important virulence trait of cariogenic biofilms. However, the concentrations of both myricetin and tt

  14. Unexplored antifungal activity of linear battacin lipopeptides against planktonic and mature biofilms of C. albicans.

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    De Zoysa, Gayan Heruka; Glossop, Hugh Douglas; Sarojini, Vijayalekshmi

    2018-02-25

    Novel antifungal agents are required against pathogenic fungi such as Candida albicans. We report the anticandidal activity of battacin lipopeptide antibiotics with previously unexplored antifungal activity. From amongst sixteen battacin lipopeptides tested against C. alibicans (SC5314) the 4-methyl hexanoyl conjugated trimeric lipopeptide 13 emerged as the lead candidate with a MIC of 6.25 μM and negligible haemolysis of mouse red blood cells. The potency of this lipopeptide was maintained under acidic conditions. Additionally, antifungal activity was further enhanced with amphotericin B at its non-haemolytic concentrations. Herein we have demonstrated for the first time that battacin lipopeptides prevent C. albicans biofilm colonisation as well as inhibit pre-formed biofilms of this fungal pathogen. XTT biofilm assays revealed that 13 prevented colonisation of C. albicans biofilms at its MIC (6.25 μM) and, at a higher concentration, eradicated 24 h (25 μM) and 48 h (62.5 μM) old preformed biofilms. In comparison, we found that amphotericin at much lower concentrations prevented biofilm colonisation (0.78 μM) and inhibited 24 h old preformed biofilms (6.25 μM), however was completely inactive against 48 h old preformed biofilms. Thus, lipopeptide 13 is more effective than amphotericin at eradicating more mature C. albicans biofilms. The membrane lytic mechanism of action of compound 13 was validated by a colorimetric assay using lipid vesicles mimicking fungal membranes in which compound 13 effected an immediate dark purple to red colour transition of suspended vesicles upon peptide interaction. In addition, TEM images of C. albicans cells exposed to 13 showed clearly disrupted cellular membranes. Interestingly, compound 13 increased the endogenous generation of reactive oxygen species (ROS) in a concentration dependent manner. In the presence of an antioxidant, ascorbic acid, ROS production was diminished yet antifungal activity

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

    Science.gov (United States)

    Morici, Paola; Fais, Roberta; Rizzato, Cosmeri

    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. PMID:27902776

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

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    Paola Morici

    Full Text Available 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.

  17. ESTUDO DO EFEITO DA TERAPIA FOTODINÂMICA ANTIMICROBIANA SOBRE A VIABILIDADE DO BIOFILME PRODUZIDO POR Candida albicans

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    Ana Paula Pinto

    2017-03-01

    Full Text Available A C. albicans é um fungo comensal e oportunista, que em casos de imunossupressão pode causar infecções e levar o indivíduo à morte. O biofilme produzido por C. albicans apresenta resistência a vários antifúngicos, pois é formado por uma matriz extracelular que dificulta a difusão dos fármacos. A Terapia Fotodinâmica Antimicrobiana (TFA é uma terapia que combina uma fonte de luz visível, um agente fotossensível (não tóxico e oxigênio. Esta interação promove a produção de espécies reativas de oxigênio (ERO’s, que alteram a permeabilidade da membrana celular e podem levar à morte celular de microrganismos. Foi realizada a TFA em biofilmes produzidos por C. albicans em diferentes fases de desenvolvimento. A fonte de luz utilizada foi um Light Emitting Diode (LED (630nm e o agente fotossenssível utilizado foi o Azul de Toluidina (AT. Os resultados demonstraram que tanto sobre a formação quanto sobre o biofilme produzido por C. albicans a TFA foi capaz de reduzir a viabilidade celular e alterar a morfologia, diminuindo a quantidade do número de células e de filamentos. Assim, a TFA demonstra ser uma potencial terapia antifúngica.

  18. Synergistic antifungal effect of chitosan-stabilized selenium nanoparticles synthesized by pulsed laser ablation in liquids against Candida albicans biofilms.

    Science.gov (United States)

    Lara, Humberto H; Guisbiers, Gregory; Mendoza, Jonathan; Mimun, Lawrence C; Vincent, Brandy A; Lopez-Ribot, Jose L; Nash, Kelly L

    2018-01-01

    Candida albicans is a major opportunistic fungal pathogen. One of the most important virulence factors that contribute to the pathogenesis of candidiasis is its ability to form biofilms. A key characteristic of Candida biofilms is their resistance to antifungal agents. Due to significant morbidity and mortality rates related to biofilm-associated drug resistance, there is an urgency to develop novel nanotechnology-based approaches preventing biofilm-related infections. In this study, we report, for the first time, the synthesis of selenium nanoparticles by irradiating selenium pellets by nanosecond pulsed laser ablation in liquid chitosan as a capping agent. Synergy of the fungicidal effect of selenium nanoparticles and chitosan was quantified by the combination index theorem of Chou-Talalay. This drug combination resulted in a potent fungicidal effect against a preformed C. albicans biofilm in a dose-response manner. By advanced electron microscopy techniques, we documented the adhesive and permeabilizing properties of chitosan, therefore allowing selenium nanoparticles to enter as the cell wall of the yeast became disrupted and distorted. Most importantly, we demonstrated a potent quantitative synergistic effect when compounds such as selenium and chitosan are combined. These chitosan-stabilized selenium nanoparticles could be used for ex vivo applications such as sterilizers for surfaces and biomedical devices.

  19. Gallic acid/hydroxypropyl-β-cyclodextrin complex: Improving solubility for application on in vitro/ in vivo Candida albicans biofilms.

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    Guilherme Rodrigues Teodoro

    Full Text Available The aim of this study was to increase the solubility of gallic acid (GA for the treatment of Candida albicans biofilm, which is very difficult to treat and requires high drug concentrations. Cyclodextrins (CDs were used for this purpose. Complexes were evaluated by phase-solubility studies, prepared by spray drying and characterized by drug loading, scanning electron microscopy (SEM and differential scanning calorimetry (DSC. The complexes were tested on C. albicans biofilm using in vitro and in vivo models. HPβCD formed soluble inclusion complexes with GA. The percentage of GA in GA/HPβCD was 10.8 ± 0.01%. The SEM and DSC analyses confirmed the formation of inclusion complexes. GA/HPβCD maintained the antimicrobial activity of the pure GA. GA/HPβCD was effective on C. albicans biofilms of 24 and 48h. The in vivo results showed an anti-inflammatory activity of GA/HPβCD with no difference in invading hypha counting among the groups. This study encourages the development of new antifungal agents.

  20. Bismuth oxide aqueous colloidal nanoparticles inhibit Candida albicans growth and biofilm formation

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    Hernandez-Delgadillo R

    2013-04-01

    Full Text Available Rene Hernandez-Delgadillo,1 Donaji Velasco-Arias,3 Juan Jose Martinez-Sanmiguel,2 David Diaz,3 Inti Zumeta-Dube,3 Katiushka Arevalo-Niño,1 Claudio Cabral-Romero2 1Facultad de Ciencias Biológicas, Instituto de Biotecnologia, Universidad Autonoma de Nuevo Leon, UANL, Monterrey, Mexico; 2Facultad de Odontología, Universidad Autonoma de Nuevo Leon, UANL, Monterrey, México; 3Facultad de Quimica, Universidad Nacional Autonoma de Mexico, UNAM, Distrito Federal, México Abstract: Multiresistance among microorganisms to common antimicrobials has become one of the most significant concerns in modern medicine. Nanomaterials are a new alternative to successfully treat the multiresistant microorganisms. Nanostructured materials are used in many fields, including biological sciences and medicine. Recently, it was demonstrated that the bactericidal activity of zero-valent bismuth colloidal nanoparticles inhibited the growth of Streptococcus mutans; however the antimycotic potential of bismuth nanostructured derivatives has not yet been studied. The main objective of this investigation was to analyze the fungicidal activity of bismuth oxide nanoparticles against Candida albicans, and their antibiofilm capabilities. Our results showed that aqueous colloidal bismuth oxide nanoparticles displayed antimicrobial activity against C. albicans growth (reducing colony size by 85% and a complete inhibition of biofilm formation. These results are better than those obtained with chlorhexidine, nystatin, and terbinafine, the most effective oral antiseptic and commercial antifungal agents. In this work, we also compared the antimycotic activities of bulk bismuth oxide and bismuth nitrate, the precursor metallic salt. These results suggest that bismuth oxide colloidal nanoparticles could be a very interesting candidate as a fungicidal agent to be incorporated into an oral antiseptic. Additionally, we determined the minimum inhibitory concentration for the synthesized

  1. 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.

  2. 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.

  3. Hibiscus sabdariffa extract inhibits in vitro biofilm formation capacity of Candida albicans isolated from recurrent urinary tract infections.

    Science.gov (United States)

    Alshami, Issam; Alharbi, Ahmed E

    2014-02-01

    To explore the prevention of recurrent candiduria using natural based approaches and to study the antimicrobial effect of Hibiscus sabdariffa (H. sabdariffa) extract and the biofilm forming capacity of Candida albicans strains in the present of the H. sabdariffa extract. In this particular study, six strains of fluconazole resistant Candida albicans isolated from recurrent candiduria were used. The susceptibility of fungal isolates, time-kill curves and biofilm forming capacity in the present of the H. sabdariffa extract were determined. Various levels minimum inhibitory concentration of the extract were observed against all the isolates. Minimum inhibitory concentration values ranged from 0.5 to 2.0 mg/mL. Time-kill experiment demonstrated that the effect was fungistatic. The biofilm inhibition assay results showed that H. sabdariffa extract inhibited biofilm production of all the isolates. The results of the study support the potential effect of H. sabdariffa extract for preventing recurrent candiduria and emphasize the significance of the plant extract approach as a potential antifungal agent.

  4. Candida albicans ethanol stimulates Pseudomonas aeruginosa WspR-controlled biofilm formation as part of a cyclic relationship involving phenazines.

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    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.

  5. 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.

  6. EFEITO DOS COMPOSTOS ORAGANOCALCOGÊNEOS (PhSe2 E (p-Cl-PhSe2 SOBRE A VIABILIDADE DO BIOFILME FORMADO POR Candida albicans

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    Marília Toledo Braga

    2017-05-01

    Full Text Available Os fungos do gênero Candida são capazes de produzir infecções superficiais ou sistêmicas em indivíduos com baixa resposta imunológica. Estes fungos promovem infecções a partir da sua capacidade de formar biofilmes. Os biofilmes formados por C. albicans são mais resistentes aos tratamentos antifúngicos convencionais. Portanto o objetivo deste trabalho foi avaliar e comparar o potencial antifúngico dos compostos organocalcogêneos (PhSe2 e (p­-Cl-PhSe2 sobre os biofilmes de C. albicans. Suspensões de C. albicans foram incubadas para a formação do biofilme e estes foram tratados com os compostos organocalcogêneos por 24 horas. Os resultados obtidos demonstraram o potencial antifúngico de ambos compostos sobre o biofilme formado por C. albicans, inibindo a viabilidade do biofilme e reduzindo a quantidade de células planctônicas. Esses compostos apresentaram uma resposta terapêutica promissora, uma vez que as opções para tratamento de infecções fúngicas é limitado.

  7. 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.

  8. [FUNCTION OF INTERCELLULAR ADHESION A, FIBRINOGEN BINDING PROTEIN, AND ACCUMULATION-ASSOCIATED PROTEIN GENES IN FORMATION OF STAPHYLOCOCCUS EPIDERMIDIS-CANDIDA ALBICANS MIXED SPECIES BIOFILMS].

    Science.gov (United States)

    Wang, Xiaoyan; Chen, Ying; Huang, Yunchao; Zhou, Youquan; Zhao, Guangqiang; Ye, Lianhua; Lei, Yujie; Tang, Qi

    2015-01-01

    To explore the function of intercellular adhesion A (icaA), fibrinogen binding protein (fbe), and accumulation-associated protein (aap) genes in formation of Staphylococcus epidermidis-Candida albicans mixed species biofilms. The experiment was divided into 3 groups: single culture of Staphylococcus epidermidis ATCC35984 (S. epidermidis group) or Candida albicans ATCC10231 (C. albicans group), and co-culture of two strains (mixed group) to build in vitro biofilm model. Biofilm mass was detected by crystal violet semi-quantitative adherence assay at 2, 4, 6, 8, 12, 24, 48, and 72 hours after incubation. XTT assay was performed to determine the growth kinetics in the same time. Scanning electron microscopy (SEM) was used to observe the ultrastructure of the biofilms after 24 and 72 hours of incubation. The expressions of icaA, fbe, and aap genes were analyzed by real-time fluorescent quantitative PCR. Crystal violet semi-quantitative adherence assay showed that the biofilms thickened at 12 hours in the S. epidermidis and mixed groups; after co-cultured for 72 hours the thickness of biofilm in mixed group was more than that in the S. epidermidis group, and there was significant difference between 2 groups at the other time (P 0.05). In C. albicans group, the biofilm started to grow at 12 hours of cultivation, but the thickness of the biofilm was significantly lower than that in the mixed group in all the time points (P 0.05) except at 12 hours (P 0.05); the A value of mixed group was significantly higher than that of the C. albicans group after 6 hours (P biofilms with complex structure formed in all groups. The real-time fluorescent quantitative PCR showed the expressions of fbe, icaA, and aap genes in mixed group increased 1.93, 1.52, and 1.46 times respectively at 72 hours compared with the S. epidermidis group (P biofilms have more complex structure and are thicker than single species biofilms of Staphylococcus epidermidis or Candida albicans, which is related to

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

    OpenAIRE

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

    1996-01-01

    Two chromogenic media, Albicans ID and CHROMagar Candida agar plates, were compared with a reference medium, Sabouraud-chloramphenicol agar, and standard methods for the identification of yeast species. This study involved 951 clinical specimens. The detection rates for the two chromogenic media for polymicrobial specimens were 20% higher than that for the Sabouraud-chloramphenicol agar plates. The rates of identification of Candida albicans for Albicans ID and CHROMagar Candida agar plates w...

  10. 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.

  11. RNA-Seq Reveals Enhanced Sugar Metabolism in Streptococcus mutans Co-cultured with Candida albicans within Mixed-Species Biofilms

    Science.gov (United States)

    He, Jinzhi; Kim, Dongyeop; Zhou, Xuedong; Ahn, Sang-Joon; Burne, Robert A.; Richards, Vincent P.; Koo, Hyun

    2017-01-01

    Early childhood caries (ECC), which can lead to rampant tooth-decay that is painful and costly to treat, is one of the most prevalent infectious diseases affecting children worldwide. Previous studies support that interactions between Streptococcus mutans and Candida albicans are associated with the pathogenesis of ECC. The presence of Candida enhances S. mutans growth, fitness and accumulation within biofilms in vitro, although the molecular basis for these behaviors is undefined. Using an established co-cultivation biofilm model and RNA-Seq, we investigated how C. albicans influences the transcriptome of S. mutans. The presence of C. albicans dramatically altered gene expression in S. mutans in the dual-species biofilm, resulting in 393 genes differentially expressed, compared to mono-species biofilms of S. mutans. By Gene Ontology analysis, the majority of up-regulated genes were related to carbohydrate transport and metabolic/catabolic processes. KEGG pathway impact analysis showed elevated pyruvate and galactose metabolism, suggesting that co-cultivation with C. albicans influences carbohydrate utilization by S. mutans. Analysis of metabolites confirmed the increases in carbohydrate metabolism, with elevated amounts of formate in the culture medium of co-cultured biofilms. Moreover, co-cultivation with C. albicans altered transcription of S. mutans signal transduction (comC and ciaRH) genes associated with fitness and virulence. Interestingly, the expression of genes for mutacins (bacteriocins) and CRISPR were down-regulated. Collectively, the data provide a comprehensive insight into S. mutans transcriptomic changes induced by C. albicans, and offer novel insights into how bacterial–fungal interactions may enhance the severity of dental caries. PMID:28642749

  12. RNA-Seq Reveals Enhanced Sugar Metabolism in Streptococcus mutans Co-cultured with Candida albicans within Mixed-Species Biofilms

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    Jinzhi He

    2017-06-01

    Full Text Available Early childhood caries (ECC, which can lead to rampant tooth-decay that is painful and costly to treat, is one of the most prevalent infectious diseases affecting children worldwide. Previous studies support that interactions between Streptococcus mutans and Candida albicans are associated with the pathogenesis of ECC. The presence of Candida enhances S. mutans growth, fitness and accumulation within biofilms in vitro, although the molecular basis for these behaviors is undefined. Using an established co-cultivation biofilm model and RNA-Seq, we investigated how C. albicans influences the transcriptome of S. mutans. The presence of C. albicans dramatically altered gene expression in S. mutans in the dual-species biofilm, resulting in 393 genes differentially expressed, compared to mono-species biofilms of S. mutans. By Gene Ontology analysis, the majority of up-regulated genes were related to carbohydrate transport and metabolic/catabolic processes. KEGG pathway impact analysis showed elevated pyruvate and galactose metabolism, suggesting that co-cultivation with C. albicans influences carbohydrate utilization by S. mutans. Analysis of metabolites confirmed the increases in carbohydrate metabolism, with elevated amounts of formate in the culture medium of co-cultured biofilms. Moreover, co-cultivation with C. albicans altered transcription of S. mutans signal transduction (comC and ciaRH genes associated with fitness and virulence. Interestingly, the expression of genes for mutacins (bacteriocins and CRISPR were down-regulated. Collectively, the data provide a comprehensive insight into S. mutans transcriptomic changes induced by C. albicans, and offer novel insights into how bacterial–fungal interactions may enhance the severity of dental caries.

  13. Treatment of Candida albicans biofilms with low-temperature plasma induced by dielectric barrier discharge and atmospheric pressure plasma jet

    International Nuclear Information System (INIS)

    Koban, Ina; Welk, Alexander; Meisel, Peter; Holtfreter, Birte; Kocher, Thomas; Matthes, Rutger; Huebner, Nils-Olaf; Kramer, Axel; Sietmann, Rabea; Kindel, Eckhard; Weltmann, Klaus-Dieter

    2010-01-01

    Because of some disadvantages of chemical disinfection in dental practice (especially denture cleaning), we investigated the effects of physical methods on Candida albicans biofilms. For this purpose, the antifungal efficacy of three different low-temperature plasma devices (an atmospheric pressure plasma jet and two different dielectric barrier discharges (DBDs)) on Candida albicans biofilms grown on titanium discs in vitro was investigated. As positive treatment controls, we used 0.1% chlorhexidine digluconate (CHX) and 0.6% sodium hypochlorite (NaOCl). The corresponding gas streams without plasma ignition served as negative treatment controls. The efficacy of the plasma treatment was determined evaluating the number of colony-forming units (CFU) recovered from titanium discs. The plasma treatment reduced the CFU significantly compared to chemical disinfectants. While 10 min CHX or NaOCl exposure led to a CFU log 10 reduction factor of 1.5, the log 10 reduction factor of DBD plasma was up to 5. In conclusion, the use of low-temperature plasma is a promising physical alternative to chemical antiseptics for dental practice.

  14. Treatment of Candida albicans biofilms with low-temperature plasma induced by dielectric barrier discharge and atmospheric pressure plasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Koban, Ina; Welk, Alexander; Meisel, Peter; Holtfreter, Birte; Kocher, Thomas [Unit of Periodontology, Dental School, University of Greifswald, Rotgerberstr. 8, 17475 Greifswald (Germany); Matthes, Rutger; Huebner, Nils-Olaf; Kramer, Axel [Institute for Hygiene and Environmental Medicine, University of Greifswald, Walther-Rathenau-Str. 49 a, 17487 Greifswald (Germany); Sietmann, Rabea [Institute of Microbiology, University of Greifswald, Friedrich-Ludwig-Jahn-Str. 15, 17487 Greifswald (Germany); Kindel, Eckhard; Weltmann, Klaus-Dieter, E-mail: ina.koban@uni-greifswald.d [Leibniz Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

    2010-07-15

    Because of some disadvantages of chemical disinfection in dental practice (especially denture cleaning), we investigated the effects of physical methods on Candida albicans biofilms. For this purpose, the antifungal efficacy of three different low-temperature plasma devices (an atmospheric pressure plasma jet and two different dielectric barrier discharges (DBDs)) on Candida albicans biofilms grown on titanium discs in vitro was investigated. As positive treatment controls, we used 0.1% chlorhexidine digluconate (CHX) and 0.6% sodium hypochlorite (NaOCl). The corresponding gas streams without plasma ignition served as negative treatment controls. The efficacy of the plasma treatment was determined evaluating the number of colony-forming units (CFU) recovered from titanium discs. The plasma treatment reduced the CFU significantly compared to chemical disinfectants. While 10 min CHX or NaOCl exposure led to a CFU log{sub 10} reduction factor of 1.5, the log{sub 10} reduction factor of DBD plasma was up to 5. In conclusion, the use of low-temperature plasma is a promising physical alternative to chemical antiseptics for dental practice.

  15. Biofilms and Wounds: An Identification Algorithm and Potential Treatment Options

    Science.gov (United States)

    Percival, Steven L.; Vuotto, Claudia; Donelli, Gianfranco; Lipsky, Benjamin A.

    2015-01-01

    Significance: The presence of a “pathogenic” or “highly virulent” biofilm is a fundamental risk factor that prevents a chronic wound from healing and increases the risk of the wound becoming clinically infected. There is presently no unequivocal gold standard method available for clinicians to confirm the presence of biofilms in a wound. Thus, to help support clinician practice, we devised an algorithm intended to demonstrate evidence of the presence of a biofilm in a wound to assist with wound management. Recent Advances: A variety of histological and microscopic methods applied to tissue biopsies are currently the most informative techniques available for demonstrating the presence of generic (not classified as pathogenic or commensal) biofilms and the effect they are having in promoting inflammation and downregulating cellular functions. Critical Issues: Even as we rely on microscopic techniques to visualize biofilms, they are entities which are patchy and dispersed rather than confluent, particularly on biotic surfaces. Consequently, detection of biofilms by microscopic techniques alone can lead to frequent false-negative results. Furthermore, visual identification using the naked eye of a pathogenic biofilm on a macroscopic level on the wound will not be possible, unlike with biofilms on abiotic surfaces. Future Direction: Lacking specific biomarkers to demonstrate microscopic, nonconfluent, virulent biofilms in wounds, the present focus on biofilm research should be placed on changing clinical practice. This is best done by utilizing an anti-biofilm toolbox approach, rather than speculating on unscientific approaches to identifying biofilms, with or without staining, in wounds with the naked eye. The approach to controlling biofilm should include initial wound cleansing, periodic debridement, followed by the application of appropriate antimicrobial wound dressings. This approach appears to be effective in removing pathogenic biofilms. PMID:26155381

  16. Persea americana Glycolic Extract: In Vitro Study of Antimicrobial Activity against Candida albicans Biofilm and Cytotoxicity Evaluation

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    D. Jesus

    2015-01-01

    Full Text Available This study evaluated the antifungal activity of Persea americana extract on Candida albicans biofilm and its cytotoxicity in macrophage culture (RAW 264.7. To determine the minimum inhibitory concentration (MIC, microdilution in broth (CLSI M27-S4 protocol was performed. Thereafter, the concentrations of 12.5, 25, 50, 100, and 200 mg/mL (n=10 with 5 min exposure were analyzed on mature biofilm in microplate wells for 48 h. Saline was used as control (n=10. After treatment, biofilm cells were scraped off and dilutions were plated on Sabouraud dextrose agar. After incubation (37°C/48 h, the values of colony forming units per milliliter (CFU/mL were converted to log10 and analyzed (ANOVA and Tukey test, 5%. The cytotoxicity of the P. americana extract was evaluated on macrophages by MTT assay. The MIC of the extract was 6.25 mg/mL and with 12.5 mg/mL there was elimination of 100% of planktonic cultures. Regarding the biofilms, a significant reduction (P<0.001 of the biofilm at concentrations of 50 (0.580±0.209 log10, 100 (0.998±0.508 log10, and 200 mg/mL (1.093±0.462 log10 was observed. The concentrations of 200 and 100 mg/mL were cytotoxic for macrophages, while the concentrations of 50, 25, and 12.5 mg/mL showed viability higher than 55%.

  17. Lab-scale preparations of Candida albicans and dual Candida albicans-Candida glabrata biofilms on the surface of medical-grade polyvinyl chloride (PVC) perfusion tube using a modified gravity-supported free-flow biofilm incubator (GS-FFBI).

    Science.gov (United States)

    Shao, Jing; Lu, KeQiao; Tian, Ge; Cui, YanYan; Yan, YuanYuan; Wang, TianMing; Zhang, XinLong; Wang, ChangZhong

    2015-02-01

    The assembly of a man-made gravity-supported free-flow biofilm incubator (GS-FFBI) was described, which was composed of a gas cushion injector and four incubators. The GS-FFBI had the characteristics of (i) a bottom-up flow direction, and (ii) lab-scale biofilm preparation without the use of a multichannel pump. Two opportunistic fungal strains, namely Candida albicans and Candida glabrata, were employed to incubate C. albicans and dual C. albicans-C. glabrata biofilms on the surface of medical-grade polyvinyl chloride perfusion tube. In terms of the results from {2, 3-bis (2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide} (XTT) assay, dry weight measurement, colony-forming unit counting, susceptibility test, and scanning electron microscopy, it was demonstrated that GS-FFBI could form both stable single and dual Candida biofilms with no significant variations among the four incubators or the three daily incubations within 21h, and could operate for at least 96h smoothly with no contamination of stock medium. The results also indicated, for the first time, that C. albicans and C. glabrata might be co-existent competitively and symbiotically in the dual biofilms with flowing media. GS-FFBI would be a useful device to study in vitro morphological and physiological features of microbial biofilms in the medical settings. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. The European Confederation of Medical Mycology (ECMM) survey of candidaemia in Italy: in vitro susceptibility of 375 Candida albicans isolates and biofilm production.

    Science.gov (United States)

    Tortorano, Anna Maria; Prigitano, Anna; Biraghi, Emanuela; Viviani, Maria Anna

    2005-10-01

    To investigate the in vitro antifungal susceptibility pattern of 375 Candida albicans bloodstream isolates recovered during the European Confederation of Medical Mycology survey of candidaemia performed in Lombardia, Italy and to test the ability to form biofilm. In vitro susceptibility to flucytosine, fluconazole, itraconazole, posaconazole, voriconazole and caspofungin was performed by broth microdilution following the NCCLS guidelines. Biofilm production was measured using the XTT reduction assay in 59 isolates selected as representative of different patterns of susceptibility to flucytosine and azoles. MICs (mg/L) at which 90% of the strains were inhibited were < or =0.25 for flucytosine, 0.25 for caspofungin, 4 for fluconazole and 0.06 for itraconazole, voriconazole and posaconazole. Flucytosine resistance was detected in five isolates and was associated with serotype B in 2/29 and serotype A in 3/346. Resistance to fluconazole was detected in 10 isolates; nine of these exhibited reduced susceptibility to the other azoles. Among the 10 patients with fluconazole-resistant C. albicans bloodstream infection, only one, an AIDS patient, had been previously treated with fluconazole. Biofilm production was observed in 23 isolates (39%) and was significantly associated with serotype B. No relationship was detected with the pattern of antifungal susceptibility. Resistance is uncommon in C. albicans isolates recovered from blood cultures, while biofilm production is a relatively frequent event. Periodic surveillance is warranted to monitor the incidence of in vitro antifungal resistance as well as of biofilm production.

  19. Secreted Aspartic Protease Cleavage of Candida albicans Msb2 Activates Cek1 MAPK Signaling Affecting Biofilm Formation and Oropharyngeal Candidiasis

    Science.gov (United States)

    Chadha, Sonia; Tati, Swetha; Conti, Heather R.; Hube, Bernhard; Cullen, Paul J.; Edgerton, Mira

    2012-01-01

    Perception of external stimuli and generation of an appropriate response are crucial for host colonization by pathogens. In pathogenic fungi, mitogen activated protein kinase (MAPK) pathways regulate dimorphism, biofilm/mat formation, and virulence. Signaling mucins, characterized by a heavily glycosylated extracellular domain, a transmembrane domain, and a small cytoplasmic domain, are known to regulate various signaling pathways. In Candida albicans, the mucin Msb2 regulates the Cek1 MAPK pathway. We show here that Msb2 is localized to the yeast cell wall and is further enriched on hyphal surfaces. A msb2Δ/Δ strain formed normal hyphae but had biofilm defects. Cek1 (but not Mkc1) phosphorylation was absent in the msb2Δ/Δ mutant. The extracellular domain of Msb2 was shed in cells exposed to elevated temperature and carbon source limitation, concomitant with germination and Cek1 phosphorylation. Msb2 shedding occurred differentially in cells grown planktonically or on solid surfaces in the presence of cell wall and osmotic stressors. We further show that Msb2 shedding and Cek1 phosphorylation were inhibited by addition of Pepstatin A (PA), a selective inhibitor of aspartic proteases (Saps). Analysis of combinations of Sap protease mutants identified a sap8Δ/Δ mutant with reduced MAPK signaling along with defects in biofilm formation, thereby suggesting that Sap8 potentially serves as a major regulator of Msb2 processing. We further show that loss of either Msb2 (msb2Δ/Δ) or Sap8 (sap8Δ/Δ) resulted in higher C. albicans surface β-glucan exposure and msb2Δ/Δ showed attenuated virulence in a murine model of oral candidiasis. Thus, Sap-mediated proteolytic cleavage of Msb2 is required for activation of the Cek1 MAPK pathway in response to environmental cues including those that induce germination. Inhibition of Msb2 processing at the level of Saps may provide a means of attenuating MAPK signaling and reducing C. albicans virulence. PMID:23139737

  20. Alternative Mating Type Configurations (a/α versus a/a or α/α) of Candida albicans Result in Alternative Biofilms Regulated by Different Pathways

    Science.gov (United States)

    Srikantha, Thyagarajan; Huang, Guanghua; Garnaas, Adam M.; Soll, David R.

    2011-01-01

    Similar multicellular structures can evolve within the same organism that may have different evolutionary histories, be controlled by different regulatory pathways, and play similar but nonidentical roles. In the human fungal pathogen Candida albicans, a quite extraordinary example of this has occurred. Depending upon the configuration of the mating type locus (a/α versus a/a or α/α), C. albicans forms alternative biofilms that appear similar morphologically, but exhibit dramatically different characteristics and are regulated by distinctly different signal transduction pathways. Biofilms formed by a/α cells are impermeable to molecules in the size range of 300 Da to 140 kDa, are poorly penetrated by human polymorphonuclear leukocytes (PMNs), and are resistant to antifungals. In contrast, a/a or α/α biofilms are permeable to molecules in this size range, are readily penetrated by PMNs, and are susceptible to antifungals. By mutational analyses, a/α biofilms are demonstrated to be regulated by the Ras1/cAMP pathway that includes Ras1→Cdc35→cAMP(Pde2—|)→Tpk2(Tpk1)→Efg1→Tec1→Bcr1, and a/a biofilms by the MAP kinase pathway that includes Mfα→Ste2→ (Ste4, Ste18, Cag1)→Ste11→Hst7→Cek2(Cek1)→Tec1. These observations suggest the hypothesis that while the upstream portion of the newly evolved pathway regulating a/a and α/α cell biofilms was derived intact from the upstream portion of the conserved pheromone-regulated pathway for mating, the downstream portion was derived through modification of the downstream portion of the conserved pathway for a/α biofilm formation. C. albicans therefore forms two alternative biofilms depending upon mating configuration. PMID:21829325

  1. Evaluation of Antimicrobial and Antifungal efficacy of Chitosan as endodontic irrigant against Enterococcus Faecalis and Candida Albicans Biofilm formed on tooth substrate.

    Science.gov (United States)

    Yadav, Pankaj; Chaudhary, Sarika; Saxena, Rajendra K; Talwar, Sangeeta; Yadav, Sudha

    2017-03-01

    Bacterial biofilms formed on the root canal wall are often difficult to remove. This study aimed to evaluate the cytotoxic effect and antibacterial efficacy of chitosan when used as root canal irrigant against E. Faecalis and Candida albicans biofilm formed on tooth substrate. The present study evaluated antibacterial effect of 0.25% Chitosan, 0.5% Chitosan, 2% chlorhexidine and 3% sodium hypochlorite against Enterococcus faecalis and Candida Albicans . Agar-well diffusion methods, minimal inhibitory concentration tests and biofilm susceptibility assays were used to determine antibacterial activity. Teeth specimens were sectioned to obtain a standardized tooth length of 12mm. Specimens were inoculated with 10 mL of the freshly prepared E. Faecalis suspension and Candida albicans for 4 weeks. The specimens were then instrumented with ProTaper rotary files F3 size. After irrigation with test solution, three sterile paper points were placed into one canal, left for 60 s and transferred to a test tube containing 1 mL of reduced transport fluid. The number of CFU in 1 mL was determined. 3-week biofilm qualitative assay showed complete inhibition of bacterial growth with 3% Sodium hypochlorite, 2% Chlorhexidine and Chitosan except saline, which showed presence of bacterial growth. Significant reduction of colony forming units (CFU)/mL was observed for the chitosan groups and the antibacterial activity of the chitosan groups was at par with 3% NaOCl and 2% Chlorhexidine. It was observed that the chitosan showed no cytotoxicity at 3mg/ml and 10% cytotoxicity at 6mg/ml. The use of chitosan as a root canal irrigant might be an alternative considering the various undesirable properties of NaOCl and chlorhexidine. Key words: Biofilm, Candida albicans, Chitosan, Cytotoxicity, Enterococcus faecalis.

  2. Candida species isolated from different body sites and their antifungal susceptibility pattern: Cross-analysis of Candida albicans and Candida glabrata biofilms.

    Science.gov (United States)

    Cataldi, Valentina; Di Campli, Emanuela; Fazii, Paolo; Traini, Tonino; Cellini, Luigina; Di Giulio, Mara

    2017-08-01

    Candida species are regular commensal in humans, but-especially in immunocompromised patients-they represent opportunistic pathogens giving rise to systemic infection. The aim of the present work was to isolate and characterize for their antifungal profile Candida species from different body sites and to analyze the biofilms produced by C. albicans and C. glabrata isolates. Eighty-one strains of Candida species from 77 patients were identified. Epidemiological study showed that the most isolated species were C. albicans (44), C. glabrata (13) and C. parapsilosis (13) mainly from Hematology, Infectious Diseases, Medicine, Neonatology and Oncology Divisions, the majority of the biological samples were swabs (44) and blood cultures (16). The analysis of the biofilm formation was performed at 24 and 48-hours comparing resistant and susceptible strains of C. albicans to resistant and susceptible strains of C. glabrata. Candida albicans has a greater ability to form biofilm compared to C. glabrata, both in the susceptible and resistant strains reaching maturity after 24 hours with a complex structure composed of blastospores, pseudohyphae, and hyphae embedded in a matrix. On the contrary, C. glabrata biofilm was composed exclusively of blastospores that in the resistant strain, after 24 hours, were organized in a compact multilayer different to the discontinuous structure observed in the susceptible analyzed strains. In conclusion, the increasing of the incidence of Candida species infection together with their emerging drug resistance also related to the biofilm forming capability underline the need to monitor their distribution and susceptibility patterns for improving the surveillance and for a correct management of the infection. © The Author 2016. 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.

  3. Exoenzyme activity and possibility identification of Candida dubliniensis among Candida albicans species isolated from vaginal candidiasis.

    Science.gov (United States)

    Jafari, Maryam; Salari, Samira; Pakshir, Keyvan; Zomorodian, Kamiar

    2017-09-01

    Vulvovaginal candidiasis (VVC) or vaginal candidiasis is a common fungal infection of the genitals causing inflammation, irritation, itching, and vaginal discharge. Common yeast infections are caused by the yeast species C. albicans. However, there are other species of Candida such as C. dubliniensis which are considered as the causative agents of this infection. Hydrolytic enzymes such as proteinase and coagulase are known as virulence factors. The aim of this study was the molecular confirmation and differentiation of C. dubliniensis among C. albicans strains isolated from women with vulvovaginal candidiasis by PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) and the evaluation of proteinase and coagulase activities. A total of 100 C. albicans strains isolated from women with vulvovaginal candidiasis referred to Shiraz medical clinics were enrolled in the study. All the isolates were primarily identified by conventional methods. PCR-RFLP method was used for the confirmation and identification of C. albicans and C. dubliniensis. Moreover, in vitro proteinase and coagulase activities of these isolates were evaluated using bovine serum albumin media and classical rabbit plasma tube test. As a result, PCR-RFLP identified 100% of the isolates as C. albicans, and no C. dubliniensis could be identified in this study. 84% of the isolates showed proteinase activity, whereas coagulase activity was only detected in 5% of the isolates. This study reveals that C. dubliniensis plays no role in vaginal candidiasis in Iranian patients. Proteinase production could be an essential virulence factor in C. albicans pathogenicity, but coagulase activity has less potential in this matter. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Drug Susceptibility of Matrix-Encapsulated Candida albicans Nano-Biofilms

    Science.gov (United States)

    2014-02-01

    Filamentous hyphae can be seen attesting the presence of true biofilms. Figure 2. Kinetics of release of amphotericin B (AMB), caspofungin (CAS) from...the nano-biofilm growth in 3D is similar in the two matrices in the absence of any drugs (Fig. 3A,B). The cell wall along the hyphae appears as...demonstrate a 3D architecture with cell wall from hyphae (blue) superimposed with vacuoles of live cells (yellow). The viability of cells not exposed to any

  5. Candida parapsilosis Biofilm Identification by Raman Spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Samek, Ota; Mlynariková, K.; Bernatová, Silvie; Ježek, Jan; Krzyžánek, Vladislav; Šiler, Martin; Zemánek, Pavel; Růžička, F.; Holá, Miroslava; Mahelová, M.

    2014-01-01

    Roč. 15, č. 12 (2014), s. 23924-23935 E-ISSN 1422-0067 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01; GA ČR GAP205/11/1687 Institutional support: RVO:68081731 Keywords : Raman spectroscopy * Candida parapsilosis * biofilm Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.862, year: 2014

  6. 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.

  7. AÇÃO ANTIFÚNGICA DE UM JATO DE PLASMA NÃO-TERMICO DE HÉLIO/AR COMPRIMIDO SOBRE BIOFILMES DE CANDIDA ALBICANS

    Directory of Open Access Journals (Sweden)

    Fernanda Ramos Figueira

    2017-01-01

    Full Text Available Os biofilmes fúngicos são uma predominante causa de infecções crônicas associadas à utilização de cateteres e próteses, conferindo resistência aos antibióticos e fatores imunológicos do hospedeiro, sendo as leveduras, do gênero Candida spp, as mais frequentemente isoladas. O plasma não-térmico, operado à pressão atmosférica, vem ganhando destaque como uma nova estratégia antimicrobiana, inclusive para erradicação de biofilmes. Este trabalho teve como objetivo avaliar a eficácia da inativação de biofilmes de Candida albicans ATCC sobre substrato de poliuretano, utilizando jatos de plasma atmosférico de 6L/min de hélio e 4L/min de ar comprimido, alternando entre sistema contínuo e pulsado, com frequência de 60Hz e distâncias de 10 a 30mm entre o bocal e substrato. Após tratamento, realizou-se a contagem das unidades formadoras de colônia e a análise morfológica da superfície do biofilme por Microscopia Eletrônica de Varredura. O melhor grupo foi o plasma de modo pulsado com distância de 30mm com redução de 92% das unidades formadoras de colônia, demonstrando ser uma tecnologia promissora para o controle de biofilmes de C. albicans.

  8. Antimicrobial activity of denture adhesive associated with Equisetum giganteum- and Punica granatum-enriched fractions against Candida albicans biofilms on acrylic resin surfaces.

    Science.gov (United States)

    Almeida, Nara Ligia Martins; Saldanha, Luiz Leonardo; da Silva, Rafaela Alves; Pinke, Karen Henriette; da Costa, Eliane Ferraz; Porto, Vinicius Carvalho; Dokkedal, Anne Lígia; Lara, Vanessa Soares

    2018-01-01

    Candida biofilms adhere to the internal surface of removable dentures, which is an etiological factor in the pathogenesis of denture stomatitis (DS). Adhesive materials are used at the base of maxillary complete dentures to improve their retention and chewing qualities. This article reports the antimicrobial activity of the enriched fractions of Equisetum giganteum and Punica granatum incorporated into a denture adhesive against C. albicans biofilm. The biofilms were induced on the surface of heat-cured acrylic resin specimens that were previously treated with a mixture of adhesive/herb extracts. The antimicrobial activity was evaluated by CFU counts, XTT reduction, and SEM and CLSM analysis. Both herb extracts amplified the anti-biofilm action of the adhesive on the acrylic resin by up to 12 h. Therefore, when these extracts were combined with COREGA®, they played a collaborative and innovative role in biofilm control and can be considered alternatives for temporary use in the treatment and/or prevention of DS.

  9. Fluorescence In Situ Hybridization with Peptide Nucleic Acid Probes for Rapid Identification of Candida albicans Directly from Blood Culture Bottles

    Science.gov (United States)

    Rigby, Susan; Procop, Gary W.; Haase, Gerhard; Wilson, Deborah; Hall, Geraldine; Kurtzman, Cletus; Oliveira, Kenneth; Von Oy, Sabina; Hyldig-Nielsen, Jens J.; Coull, James; Stender, Henrik

    2002-01-01

    A new fluorescence in situ hybridization (FISH) method that uses peptide nucleic acid (PNA) probes for identification of Candida albicans directly from positive-blood-culture bottles in which yeast was observed by Gram staining (herein referred to as yeast-positive blood culture bottles) is described. The test (the C. albicans PNA FISH method) is based on a fluorescein-labeled PNA probe that targets C. albicans 26S rRNA. The PNA probe is added to smears made directly from the contents of the blood culture bottle and hybridized for 90 min at 55°C. Unhybridized PNA probe is removed by washing of the mixture (30 min), and the smears are examined by fluorescence microscopy. The specificity of the method was confirmed with 23 reference strains representing phylogenetically related yeast species and 148 clinical isolates covering the clinically most significant yeast species, including C. albicans (n = 72), C. dubliniensis (n = 58), C. glabrata (n = 5), C. krusei (n = 2), C. parapsilosis (n = 4), and C. tropicalis (n = 3). The performance of the C. albicans PNA FISH method as a diagnostic test was evaluated with 33 routine and 25 simulated yeast-positive blood culture bottles and showed 100% sensitivity and 100% specificity. It is concluded that this 2.5-h method for the definitive identification of C. albicans directly from yeast-positive blood culture bottles provides important information for optimal antifungal therapy and patient management. PMID:12037084

  10. 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)

  11. Polymer multilayers loaded with antifungal β-peptides kill planktonic Candida albicans and reduce formation of fungal biofilms on the surfaces of flexible catheter tubes.

    Science.gov (United States)

    Raman, Namrata; Lee, Myung-Ryul; Palecek, Sean P; Lynn, David M

    2014-10-10

    Candida albicans is the most common fungal pathogen responsible for hospital-acquired infections. Most C. albicans infections are associated with the implantation of medical devices that act as points of entry for the pathogen and as substrates for the growth of fungal biofilms that are notoriously difficult to eliminate by systemic administration of conventional antifungal agents. In this study, we report a fill-and-purge approach to the layer-by-layer fabrication of biocompatible, nanoscale 'polyelectrolyte multilayers' (PEMs) on the luminal surfaces of flexible catheters, and an investigation of this platform for the localized, intraluminal release of a cationic β-peptide-based antifungal agent. We demonstrate that polyethylene catheter tubes with luminal surfaces coated with multilayers ~700nm thick fabricated from poly-l-glutamic acid (PGA) and poly-l-lysine (PLL) can be loaded, post-fabrication, by infusion with β-peptide, and that this approach promotes extended intraluminal release of this agent (over ~4months) when incubated in physiological media. The β-peptide remained potent against intraluminal inoculation of the catheters with C. albicans and substantially reduced the formation of C. albicans biofilms on the inner surfaces of film-coated catheters. Finally, we report that these β-peptide-loaded coatings exhibit antifungal activity under conditions that simulate intermittent catheter use and microbial challenge for at least three weeks. We conclude that β-peptide-loaded PEMs offer a novel and promising approach to kill C. albicans and prevent fungal biofilm formation on surfaces, with the potential to substantially reduce the incidence of device-associated infections in indwelling catheters. β-Peptides comprise a promising new class of antifungal agents that could help address problems associated with the use of conventional antifungal agents. The versatility of the layer-by-layer approach used here thus suggests additional opportunities to

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

    Science.gov (United States)

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

    1996-02-01

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

  13. Bisbibenzyls, a new type of antifungal agent, inhibit morphogenesis switch and biofilm formation through upregulation of DPP3 in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Li Zhang

    Full Text Available The yeast-to-hypha transition plays a crucial role in the pathogenesis of C. albicans. Farnesol, a quorum sensing molecule (QSM secreted by the fungal itself, could prevent the formation of hyphae and subsequently lead to the defect of biofilm formation. The DPP3, encoding phosphatase, is a key gene in regulating farnesol synthesis. In this study, we screened 24 bisbibenzyls and 2 bibenzyls that were isolated from bryophytes or chemically synthesized by using CLSI method for antifungal effect. Seven bisbibenzyls were found to have antifungal effects with IC(80 less than 32 µg/ml, and among them, plagiochin F, isoriccardin C and BS-34 were found to inhibit the hyphae and biofilm formation of C. albicans in a dose-dependent manner. To uncover the underlying relationship between morphogenesis switch and QSM formation, we measured the farnesol production by HPLC-MS and quantified Dpp3 expression by detecting the fluorescent intensity of green fluorescent protein tagged strain using Confocal Laser Scanning microscopy and Multifunction Microplate Reader. The DPP3 transcripts were determined by real-time PCR. The data indicated that the bisbibenzyls exerted antifungal effects through stimulating the synthesis of farnesol via upregulation of Dpp3, suggesting a potential antifungal application of bisbibenzyls. In addition, our assay provides a novel, visual and convenient method to measure active compounds against morphogenesis switch.

  14. Identification, antifungal resistance profile, in vitro biofilm formation and ultrastructural characteristics of Candida species isolated from diabetic foot patients in Northern India

    Directory of Open Access Journals (Sweden)

    D Kumar

    2016-01-01

    Full Text Available Purpose: Diabetic foot ulcers are a serious cause of diagnostic and therapeutic concern. The following study was undertaken to determine the fungal causes of diabetic foot ulcers, with their phenotypic and genotypic characterisation. Materials and Methods: A total of 155 diabetic foot ulcers were studied for 1 year. Deep tissue specimen was collected from the wounds, and crushed samples were plated on Sabouraud dextrose agar with chloramphenicol (0.05 g. Identification was done by growth on cornmeal agar, germ tube formation and urease test. For molecular identification, conserved portion of the 18S rDNA region, the adjacent internal transcribed spacer 1 (ITS1 and a portion of the 28S rDNA region were amplified, using the ITS1 and ITS2 primers. Antifungal susceptibility against voriconazole, fluconazole and amphotericin B was determined by standard broth microdilution method. Biofilm formation was studied in three steps. First, on the surface of wells of microtiter plates followed by quantification of growth by fungal metabolism measurement. Finally, biofilms were analysed by scanning electron microscopy (SEM. Results: Fungal aetiology was found in 75 patients (48.38%. All were identified as Candida species (100%. The prevalence of different species was Candida tropicalis (34.6%, Candida albicans (29.3%, Candida krusei (16.0%, Candida parapsilosis (10.6%, Candida glabrata (9.33%. All were susceptible to amphotericin B (100%. On microtiter plate, all the isolates were viable within 48 h showing biofilms. The metabolic activity of cells in the biofilm increased with cellular mass, especially in the first 24 h. On SEM, majority showed budding yeast form. Conclusion: Non-albicans Candida spp. with potential biofilm forming ability are emerging as a predominant cause of diabetic foot ulcers.

  15. Identification, antifungal resistance profile, in vitro biofilm formation and ultrastructural characteristics of Candida species isolated from diabetic foot patients in Northern India.

    Science.gov (United States)

    Kumar, D; Banerjee, T; Chakravarty, J; Singh, S K; Dwivedi, A; Tilak, R

    2016-01-01

    Diabetic foot ulcers are a serious cause of diagnostic and therapeutic concern. The following study was undertaken to determine the fungal causes of diabetic foot ulcers, with their phenotypic and genotypic characterisation. A total of 155 diabetic foot ulcers were studied for 1 year. Deep tissue specimen was collected from the wounds, and crushed samples were plated on Sabouraud dextrose agar with chloramphenicol (0.05 g). Identification was done by growth on cornmeal agar, germ tube formation and urease test. For molecular identification, conserved portion of the 18S rDNA region, the adjacent internal transcribed spacer 1 (ITS1) and a portion of the 28S rDNA region were amplified, using the ITS1 and ITS2 primers. Antifungal susceptibility against voriconazole, fluconazole and amphotericin B was determined by standard broth microdilution method. Biofilm formation was studied in three steps. First, on the surface of wells of microtiter plates followed by quantification of growth by fungal metabolism measurement. Finally, biofilms were analysed by scanning electron microscopy (SEM). Fungal aetiology was found in 75 patients (48.38%). All were identified as Candida species (100%). The prevalence of different species was Candida tropicalis (34.6%), Candida albicans (29.3%), Candida krusei (16.0%), Candida parapsilosis (10.6%), Candida glabrata (9.33%). All were susceptible to amphotericin B (100%). On microtiter plate, all the isolates were viable within 48 h showing biofilms. The metabolic activity of cells in the biofilm increased with cellular mass, especially in the first 24 h. On SEM, majority showed budding yeast form. Non-albicans Candida spp. with potential biofilm forming ability are emerging as a predominant cause of diabetic foot ulcers.

  16. Evaluation of SOC for the presumptive identification of Candida albicans and Cryptococcus neoformans.

    Science.gov (United States)

    Fleming, W H; Knezek, K L; Dorn, G L

    1987-01-01

    SOC, a fungal growth medium composed of Solryth, oxgall, and caffeic acid, was evaluated as a medium to provide rapid, differential identification of Candida albicans and Cryptococcus neoformans. Using a variety of common isolation media to produce the yeast inocula, the germ tube methods tested ranked in the following order of decreasing sensitivity: SOC (97% +/- 1), serum (92% +/- 5), rabbit coagulase plasma with EDTA in combination with tryptic soy broth (89% +/- 5), TOC (89% +/- 6), and rabbit coagulase plasma with EDTA (83% +/- 4). In chlamydospore production, SOC also proved to be the most sensitive after 24 h incubation: SOC (96% +/- 2), TOC (80% +/- 2), and cornmeal-Tween 80 agar (14% +/- 3). Other medically important yeasts showed normal patterns of growth within 24 h on SOC, thus assisting in their identification. Eighty strains of Cryptococcus neoformans showed characteristic brown pigmentation on SOC and TOC within 18 h, while all other species of the genus Cryptococcus and 229 Candida isolates did not show a change in pigmentation.

  17. Biofilms.

    Science.gov (United States)

    López, Daniel; Vlamakis, Hera; Kolter, Roberto

    2010-07-01

    The ability to form biofilms is a universal attribute of bacteria. Biofilms are multicellular communities held together by a self-produced extracellular matrix. The mechanisms that different bacteria employ to form biofilms vary, frequently depending on environmental conditions and specific strain attributes. In this review, we emphasize four well-studied model systems to give an overview of how several organisms form biofilms: Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. Using these bacteria as examples, we discuss the key features of biofilms as well as mechanisms by which extracellular signals trigger biofilm formation.

  18. Structural Properties and Antifungal Activity against Candida albicans Biofilm of Different Composite Layers Based on Ag/Zn Doped Hydroxyapatite-Polydimethylsiloxanes

    Directory of Open Access Journals (Sweden)

    Andreea Groza

    2016-04-01

    Full Text Available Modern medicine is still struggling to find new and more effective methods for fighting off viruses, bacteria and fungi. Among the most dangerous and at times life-threatening fungi is Candida albicans. Our work is focused on surface and structural characterization of hydroxyapatite, silver doped hydroxyapatite and zinc doped hydroxyapatite deposited on a titanium substrate previously coated with polydimethylsiloxane (HAp-PDMS, Ag:HAp-PDMS, Zn:HAp-PDMS by different techniques: Scanning Electron Microscopy (SEM, Glow Discharge Optical Emission Spectroscopy (GDOES and Fourier Transform Infrared Spectroscopy (FTIR. The morphological studies revealed that the use of the PDMS polymer as an interlayer improves the quality of the coatings. The structural characterizations of the thin films revealed the basic constituents of both apatitic and PDMS structure. In addition, the GD depth profiles indicated the formation of a composite material as well as the successful embedding of the HAp, Zn:HAp and Ag:HAp into the polymer. On the other hand, in vitro evaluation of the antifungal properties of Ag:HAp-PDMS and Zn:HAp-PDMS demonstrated the fungicidal effects of Ag:HAp-PDMS and the potential antifungal effect of Zn:HAp-PDMS composite layers against C. albicans biofilm. The results acquired in this research complete previous research on the potential use of new complex materials produced by nanotechnology in biomedicine.

  19. Biofilms

    OpenAIRE

    López, Daniel; Vlamakis, Hera; Kolter, Roberto

    2010-01-01

    The ability to form biofilms is a universal attribute of bacteria. Biofilms are multicellular communities held together by a self-produced extracellular matrix. The mechanisms that different bacteria employ to form biofilms vary, frequently depending on environmental conditions and specific strain attributes. In this review, we emphasize four well-studied model systems to give an overview of how several organisms form biofilms: Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and ...

  20. 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.

  1. Identification of different bacterial species in biofilms using confocal Raman microscopy

    Science.gov (United States)

    Beier, Brooke D.; Quivey, Robert G.; Berger, Andrew J.

    2010-11-01

    Confocal Raman microspectroscopy is used to discriminate between different species of bacteria grown in biofilms. Tests are performed using two bacterial species, Streptococcus sanguinis and Streptococcus mutans, which are major components of oral plaque and of particular interest due to their association with healthy and cariogenic plaque, respectively. Dehydrated biofilms of these species are studied as a simplified model of dental plaque. A prediction model based on principal component analysis and logistic regression is calibrated using pure biofilms of each species and validated on pure biofilms grown months later, achieving 96% accuracy in prospective classification. When biofilms of the two species are partially mixed together, Raman-based identifications are achieved within ~2 μm of the boundaries between species with 97% accuracy. This combination of spatial resolution and predication accuracy should be suitable for forming images of species distributions within intact two-species biofilms.

  2. Confocal Raman microscopy for identification of bacterial species in biofilms

    Science.gov (United States)

    Beier, Brooke D.; Quivey, Robert G.; Berger, Andrew J.

    2011-03-01

    Implemented through a confocal microscope, Raman spectroscopy has been used to distinguish between biofilm samples of two common oral bacteria species, Streptococcus sanguinis and mutans, which are associated with healthy and cariogenic plaque, respectively. Biofilms of these species are studied as a model of dental plaque. A prediction model has been calibrated and validated using pure biofilms. This model has been used to identify the species of transferred and dehydrated samples (much like a plaque scraping) as well as hydrated biofilms in situ. Preliminary results of confocal Raman mapping of species in an intact two-species biofilm will be shown.

  3. 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.

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

    Science.gov (United States)

    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.

  5. Comparison of VITEK 2 YST Card and API 20C AUX system in identification of non- albicans Candida species

    Directory of Open Access Journals (Sweden)

    Süleyman Durmaz

    2012-03-01

    Full Text Available Objectives: In the present study, it was aimed to compare results obtained by using VITEK 2 YST Card (bioMérieux, France with those obtained by using API 20C AUX (bioMérieux, France for identification of non- albicans Candida species, which was isolated from various clinical samples, at level of species.Materials and methods: Forty-one non-albicans Candida isolates, which were isolated from 28 urine, 10 blood and 3 vaginal swab specimens, and found to be negative by germ tube test, were identified by using VITEK 2 YST Card (bioMérieux, France. In addition, microscopic morphology was assessed in corn-meal Tween 80 agar, while carbohydrate assimilation was assessed by using commercially available API 20C AUX kit (bioMérieux, France.Results: Thirty-four isolates (82.9% were identified as identical species by these 2 systems, while different results were obtained in 7 isolates (17.1%. 5 isolates, identified as Candida glabrata by API 20C AUX system, were identified as Candida tropicalis (n=2, Candida krusei, Candida lipolitica and Candida kefyr by VITEK 2 YST Card. One other isolate, identified as C.tropicalis, was identified as Candida parapsilosis; and additional one isolate, identified as C.parapsilosis, was identified as C.tropicalis.Conclusion: It was concluded that one should be cautious in the identification of C.glabrata, in particular, C.tropicalis and C.parapsilosis, although between VITEK 2 YST Card and API 20C AUX system results was found largely similarity in identification of non-albicans Candida spp.

  6. The potential of Raman spectroscopy for the identification of biofilm formation by Staphylococcus epidermidis

    International Nuclear Information System (INIS)

    Samek, O; Al-Marashi, J F M; Telle, H H

    2010-01-01

    We report on an investigation into a common problem in microbiology laboratories, which is associated with the difficulty of distinguishing/recognising different strains of the genus Staphylococcus. We demonstrate the potential of Raman spectroscopy as a rapid techniques allowing for the identification of different isolates for the detection of biofilm-positive and biofilm-negative Staphylococcus epidermidis strains. For this, the recorded spectra were interpreted using the approach of principal component analysis (PCA)

  7. Candida albicans isolated from urine: Phenotypic and molecular identification, virulence factors and antifungal susceptibility

    Directory of Open Access Journals (Sweden)

    Laura Wiebusch

    2017-07-01

    Conclusions: C. albicans isolates from urine have a high capacity for virulence and can be associated with infectious processes. Furthermore, the high percentage of isolates resistant to itraconazole is important because this antifungal agent is commonly used to treat fungal infections in the hospital environment.

  8. Identification of small molecules that disrupt vacuolar function in the pathogen Candida albicans.

    Directory of Open Access Journals (Sweden)

    Helene Tournu

    Full Text Available The fungal vacuole is a large acidified organelle that performs a variety of cellular functions. At least a sub-set of these functions are crucial for pathogenic species of fungi, such as Candida albicans, to survive within and invade mammalian tissue as mutants with severe defects in vacuolar biogenesis are avirulent. We therefore sought to identify chemical probes that disrupt the normal function and/or integrity of the fungal vacuole to provide tools for the functional analysis of this organelle as well as potential experimental therapeutics. A convenient indicator of vacuolar integrity based upon the intracellular accumulation of an endogenously produced pigment was adapted to identify Vacuole Disrupting chemical Agents (VDAs. Several chemical libraries were screened and a set of 29 compounds demonstrated to reproducibly cause loss of pigmentation, including 9 azole antifungals, a statin and 3 NSAIDs. Quantitative analysis of vacuolar morphology revealed that (excluding the azoles a sub-set of 14 VDAs significantly alter vacuolar number, size and/or shape. Many C. albicans mutants with impaired vacuolar function are deficient in the formation of hyphal elements, a process essential for its pathogenicity. Accordingly, all 14 VDAs negatively impact C. albicans hyphal morphogenesis. Fungal selectivity was observed for approximately half of the VDA compounds identified, since they did not alter the morphology of the equivalent mammalian organelle, the lysosome. Collectively, these compounds comprise of a new collection of chemical probes that directly or indirectly perturb normal vacuolar function in C. albicans.

  9. 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

  10. Identification of biofilm-associated cluster (bac in Pseudomonas aeruginosa involved in biofilm formation and virulence.

    Directory of Open Access Journals (Sweden)

    Camille Macé

    Full Text Available Biofilms are prevalent in diseases caused by Pseudomonas aeruginosa, an opportunistic and nosocomial pathogen. By a proteomic approach, we previously identified a hypothetical protein of P. aeruginosa (coded by the gene pA3731 that was accumulated by biofilm cells. We report here that a Delta pA3731 mutant is highly biofilm-defective as compared with the wild-type strain. Using a mouse model of lung infection, we show that the mutation also induces a defect in bacterial growth during the acute phase of infection and an attenuation of the virulence. The pA3731 gene is found to control positively the ability to swarm and to produce extracellular rhamnolipids, and belongs to a cluster of 4 genes (pA3729-pA3732 not previously described in P. aeruginosa. Though the protein PA3731 has a predicted secondary structure similar to that of the Phage Shock Protein, some obvious differences are observed compared to already described psp systems, e.g., this unknown cluster is monocistronic and no homology is found between the other proteins constituting this locus and psp proteins. As E. coli PspA, the amount of the protein PA3731 is enlarged by an osmotic shock, however, not affected by a heat shock. We consequently named this locus bac for biofilm-associated cluster.

  11. Visual Analysis of DNA Microarray Data for Accurate Molecular Identification of Non-albicans Candida Isolates from Patients with Candidemia Episodes

    OpenAIRE

    De Luca Ferrari, Michela; Ribeiro Resende, Mariângela; Sakai, Kanae; Muraosa, Yasunori; Lyra, Luzia; Gonoi, Tohru; Mikami, Yuzuru; Tominaga, Kenichiro; Kamei, Katsuhiko; Zaninelli Schreiber, Angelica; Trabasso, Plinio; Moretti, Maria Luiza

    2013-01-01

    The performance of a visual slide-based DNA microarray for the identification of non-albicans Candida spp. was evaluated. Among 167 isolates that had previously been identified by Vitek 2, the agreement between DNA microarray and sequencing results was 97.6%. This DNA microarray platform showed excellent performance.

  12. 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 ...

  13. Identification of Candida Species Using MP65 Gene and Evaluation of the Candida albicans MP65 Gene Expression in BALB/C Mice.

    Science.gov (United States)

    Bineshian, Farahnaz; Yadegari, Mohammad Hossien; Sharifi, Zohre; Akbari Eidgahi, Mohammadreza; Nasr, Reza

    2015-05-01

    Systemic candidiasis is a major public health concern. In particular, in immunocompromised people, such as patients with neutropenia, patients with Acquired Immune Deficiency Syndrome (AIDS) and cancer who are undergoing antiballistic chemotherapy or bone marrow transplants, and people with diabetes. Since the clinical signs and symptoms are nonspecific, early diagnosis is often difficult. The 65-kDa mannoprotein (MP65) gene of Candida albicans is appropriate for detection and identification of systemic candidiasis. This gene encodes a putative b-glucanase mannoprotein of 65 kDa, which plays a major role in the host-fungus relationship, morphogenesis and pathogenicity. The current study aimed to identify different species of Candida (C. albicans, C. glabrata and C. parapsilosis) using the Polymerase Chain Reaction (PCR) technique and also to evaluate C. albicans MP65 gene expression in BALB/C mice. All yeast isolates were identified on cornmeal agar supplemented with tween-80, germ tube formation in serum, and assimilation of carbon sources in the API 20 C AUX yeast identification system. Polymerase Chain Reaction was performed on all samples using species-specific primers for the MP65 65 kDa gene. After RNA extraction, cDNA synthesis was performed by the Maxime RT Pre Mix kit. Candida albicans MP65 gene expression was evaluated by quantitative Real-Time (q Real-Time) and Real-Time (RT) PCR techniques. The 2-ΔΔCT method was used to analyze relative changes in gene expression of MP65. For statistical analysis, nonparametric Wilcoxon test was applied using the SPSS version 16 software. Using biochemical methods, one hundred, six and one isolates of clinical samples were determined as C. albicans, C. glabrata and C. parapsilosis, respectively. Species-specific primers for PCR experiments were applied to clinical specimens, and in all cases a single expected band for C. albicans, C. glabrata and C. parapsilosis was obtained (475, 361 and 124 base pairs, respectively

  14. 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).

  15. 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.

  16. A versatile overexpression strategy in the pathogenic yeast Candida albicans: identification of regulators of morphogenesis and fitness.

    Directory of Open Access Journals (Sweden)

    Murielle Chauvel

    Full Text Available Candida albicans is the most frequently encountered human fungal pathogen, causing both superficial infections and life-threatening systemic diseases. Functional genomic studies performed in this organism have mainly used knock-out mutants and extensive collections of overexpression mutants are still lacking. Here, we report the development of a first generation C. albicans ORFeome, the improvement of overexpression systems and the construction of two new libraries of C. albicans strains overexpressing genes for components of signaling networks, in particular protein kinases, protein phosphatases and transcription factors. As a proof of concept, we screened these collections for genes whose overexpression impacts morphogenesis or growth rates in C. albicans. Our screens identified genes previously described for their role in these biological processes, demonstrating the functionality of our strategy, as well as genes that have not been previously associated to these processes. This article emphasizes the potential of systematic overexpression strategies to improve our knowledge of regulatory networks in C. albicans. The C. albicans plasmid and strain collections described here are available at the Fungal Genetics Stock Center. Their extension to a genome-wide scale will represent important resources for the C. albicans community.

  17. Identification of anti-biofilm components in Withania somnifera and their effect on virulence of Streptococcus mutans biofilms.

    Science.gov (United States)

    Pandit, S; Cai, J N; Song, K Y; Jeon, J G

    2015-08-01

    The aim of this study was to identify components of the Withania somnifera that could show anti-virulence activity against Streptococcus mutans biofilms. The anti-acidogenic activity of fractions separated from W. somnifera was compared, and then the most active anti-acidogenic fraction was chemically characterized using gas chromatography-mass spectroscopy. The effect of the identified components on the acidogenicity, aciduricity and extracellular polymeric substances (EPS) formation of S. mutans UA159 biofilms was evaluated. The change in accumulation and acidogenicity of S. mutans UA159 biofilms by periodic treatments (10 min per treatment) with the identified components was also investigated. Of the fractions, n-hexane fraction showed the strongest anti-acidogenic activity and was mainly composed of palmitic, linoleic and oleic acids. Of the identified components, linoleic and oleic acids strongly affected the acid production rate, F-ATPase activity and EPS formation of the biofilms. Periodic treatment with linoleic and oleic acids during biofilm formation also inhibited the biofilm accumulation and acid production rate of the biofilms without killing the biofilm bacteria. These results suggest that linoleic and oleic acids may be effective agents for restraining virulence of S. mutans biofilms. Linoleic and oleic acids may be promising agents for controlling virulence of cariogenic biofilms and subsequent dental caries formation. © 2015 The Society for Applied Microbiology.

  18. Identification of capsule, biofilm, lateral flagellum, and type IV pili in Vibrio mimicus strains.

    Science.gov (United States)

    Tercero-Alburo, J J; González-Márquez, H; Bonilla-González, E; Quiñones-Ramírez, E I; Vázquez-Salinas, C

    2014-11-01

    Vibrio mimicus is a bacterium that causes gastroenteritis; it is closely related to Vibrio cholerae, and can cause acute diarrhea like cholera- or dysentery-type diarrhea. It is distributed worldwide. Factors associated with virulence (such as hemolysins, enterotoxins, proteases, phospholipases, aerobactin, and hemagglutinin) have been identified; however, its pathogenicity mechanism is still unknown. In pathogenic Vibrio species such as V. cholerae, Vibrio. parahaemolyticus and Vibrio vulnificus, capsule, biofilms, lateral flagellum, and type IV pili are structures described as essential for pathogenicity. These structures had not been described in V. mimicus until this work. We used 20 V. mimicus strains isolated from water (6), oyster (9), and fish (5) samples and we were able to identify the capsule, biofilm, lateral flagellum, and type IV pili through phenotypic tests, electron microscopy, PCR, and sequencing. In all tested strains, we observed and identified the presence of capsular exopolysaccharide, biofilm formation in an in vitro model, as well as swarming, multiple flagellation, and pili. In addition, we identified homologous genes to those described in other bacteria of the genus in which these structures have been found. Identification of these structures in V. mimicus is a contribution to the biology of this organism and can help to reveal its pathogenic behavior. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Mimicking disinfection and drying of biofilms in contaminated endoscopes

    NARCIS (Netherlands)

    Kovaleva, J.; Degener, J. E.; van der Mei, H. C.

    2010-01-01

    The effects of peracetic acid-based (PAA) disinfectant with, and without, additional drying on Candida albicans, Candida parapsilosis, Pseudomonas aeruginosa and Stenotrophomonas maltophilia, isolated from contaminated flexible endoscopes, in single-and dual-species biofilms were studied. Biofilms

  20. Identification and functional characterization of Rca1, a transcription factor involved in both antifungal susceptibility and host response in Candida albicans.

    Science.gov (United States)

    Vandeputte, Patrick; Pradervand, Sylvain; Ischer, Françoise; Coste, Alix T; Ferrari, Sélène; Harshman, Keith; Sanglard, Dominique

    2012-07-01

    The identification of novel transcription factors associated with antifungal response may allow the discovery of fungus-specific targets for new therapeutic strategies. A collection of 241 Candida albicans transcriptional regulator mutants was screened for altered susceptibility to fluconazole, caspofungin, amphotericin B, and 5-fluorocytosine. Thirteen of these mutants not yet identified in terms of their role in antifungal response were further investigated, and the function of one of them, a mutant of orf19.6102 (RCA1), was characterized by transcriptome analysis. Strand-specific RNA sequencing and phenotypic tests assigned Rca1 as the regulator of hyphal formation through the cyclic AMP/protein kinase A (cAMP/PKA) signaling pathway and the transcription factor Efg1, but also probably through its interaction with a transcriptional repressor, most likely Tup1. The mechanisms responsible for the high level of resistance to caspofungin and fluconazole observed resulting from RCA1 deletion were investigated. From our observations, we propose that caspofungin resistance was the consequence of the deregulation of cell wall gene expression and that fluconazole resistance was linked to the modulation of the cAMP/PKA signaling pathway activity. In conclusion, our large-scale screening of a C. albicans transcription factor mutant collection allowed the identification of new effectors of the response to antifungals. The functional characterization of Rca1 assigned this transcription factor and its downstream targets as promising candidates for the development of new therapeutic strategies, as Rca1 influences host sensing, hyphal development, and antifungal response.

  1. Identification of antifungal compounds active against Candida albicans using an improved high-throughput Caenorhabditis elegans assay.

    Directory of Open Access Journals (Sweden)

    Ikechukwu Okoli

    2009-09-01

    Full Text Available Candida albicans, the most common human pathogenic fungus, can establish a persistent lethal infection in the intestine of the microscopic nematode Caenorhabditis elegans. The C. elegans-C. albicans infection model was previously adapted to screen for antifungal compounds. Modifications to this screen have been made to facilitate a high-throughput assay including co-inoculation of nematodes with C. albicans and instrumentation allowing precise dispensing of worms into assay wells, eliminating two labor-intensive steps. This high-throughput method was utilized to screen a library of 3,228 compounds represented by 1,948 bioactive compounds and 1,280 small molecules derived via diversity-oriented synthesis. Nineteen compounds were identified that conferred an increase in C. elegans survival, including most known antifungal compounds within the chemical library. In addition to seven clinically used antifungal compounds, twelve compounds were identified which are not primarily used as antifungal agents, including three immunosuppressive drugs. This assay also allowed the assessment of the relative minimal inhibitory concentration, the effective concentration in vivo, and the toxicity of the compound in a single assay.

  2. 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.

  3. 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.

  4. Identification of Candida albicans and Candida dubliniensis Species Isolated from Bronchoalveolar Lavage Samples Using Genotypic and Phenotypic Methods

    Directory of Open Access Journals (Sweden)

    Sahar Kianipour

    2018-01-01

    Full Text Available Background: Candida dubliniensis is a newly diagnosed species very similar to Candida albicans phenotypically and first discovered in the mouth of people with AIDS in 1995. Among the different phenotypic and genotypic methods, a cost-effective method should be selected which makes it possible to differentiate these similar species. Materials and Methods: Polymerase chain reaction (PCR-restriction fragment length polymorphism with MspI enzyme and the Duplex-PCR method were done by DNA extraction using boiling. The sequencing of the amplified ribosomal region was used to confirm the C. dubliniensis species. Direct examination and colony count of the yeasts were applied for bronchoalveolar lavage (BAL samples and the growth rate of the yeasts were studied at 45°C. To understand the ability formation of chlamydoconidia in yeast isolates, they were separately cultured on the sunflower seed agar, wheat flour agar, and corn meal agar media. Results: Fifty-nine (49.2% yeast colonies were identified from the total of 120 BAL specimens. Twenty-nine isolated yeasts; including 17 (58.6% of C. albicans/dubliniensis complex and 12 (41.4% of nonalbicans isolates produced pseudohypha or blastoconidia in direct smear with a mean colony count of 42000 CFU/mL. C. albicans with the frequency of 15 (42.9% were the most common isolated yeasts, whereas C. dubliniensis was identified in two nonHIV patients. Conclusion: Sequencing of the replicated gene fragment is the best method for identifying the yeasts, but the determination of the species by phenotypic methods such as the creation of chlamydoconidia in sunflower seeds agar and wheat flour agar media can be cost-effective, have sensitivity and acceptable quality.

  5. Identification of Candida albicans and Candida dubliniensis Species Isolated from Bronchoalveolar Lavage Samples Using Genotypic and Phenotypic Methods.

    Science.gov (United States)

    Kianipour, Sahar; Ardestani, Mohammad Emami; Dehghan, Parvin

    2018-01-01

    Candida dubliniensis is a newly diagnosed species very similar to Candida albicans phenotypically and first discovered in the mouth of people with AIDS in 1995. Among the different phenotypic and genotypic methods, a cost-effective method should be selected which makes it possible to differentiate these similar species. Polymerase chain reaction (PCR)-restriction fragment length polymorphism with MspI enzyme and the Duplex-PCR method were done by DNA extraction using boiling. The sequencing of the amplified ribosomal region was used to confirm the C. dubliniensis species. Direct examination and colony count of the yeasts were applied for bronchoalveolar lavage (BAL) samples and the growth rate of the yeasts were studied at 45°C. To understand the ability formation of chlamydoconidia in yeast isolates, they were separately cultured on the sunflower seed agar, wheat flour agar, and corn meal agar media. Fifty-nine (49.2%) yeast colonies were identified from the total of 120 BAL specimens. Twenty-nine isolated yeasts; including 17 (58.6%) of C. albicans / dubliniensis complex and 12 (41.4%) of nonalbicans isolates produced pseudohypha or blastoconidia in direct smear with a mean colony count of 42000 CFU/mL. C. albicans with the frequency of 15 (42.9%) were the most common isolated yeasts, whereas C. dubliniensis was identified in two nonHIV patients. Sequencing of the replicated gene fragment is the best method for identifying the yeasts, but the determination of the species by phenotypic methods such as the creation of chlamydoconidia in sunflower seeds agar and wheat flour agar media can be cost-effective, have sensitivity and acceptable quality.

  6. Identification of Genes Involved in Polysaccharide-Independent Staphylococcus aureus Biofilm Formation

    Science.gov (United States)

    Boles, Blaise R.; Thoendel, Matthew; Roth, Aleeza J.; Horswill, Alexander R.

    2010-01-01

    Staphylococcus aureus is a potent biofilm former on host tissue and medical implants, and biofilm growth is a critical virulence determinant for chronic infections. Recent studies suggest that many clinical isolates form polysaccharide-independent biofilms. However, a systematic screen for defective mutants has not been performed to identify factors important for biofilm formation in these strains. We created a library of 14,880 mariner transposon mutants in a S. aureus strain that generates a proteinaceous and extracellular DNA based biofilm matrix. The library was screened for biofilm defects and 31 transposon mutants conferred a reproducible phenotype. In the pool, 16 mutants overproduced extracellular proteases and the protease inhibitor α2-macroglobulin restored biofilm capacity to 13 of these mutants. The other 15 mutants in the pool displayed normal protease levels and had defects in genes involved in autolysis, osmoregulation, or uncharacterized membrane proteins. Two transposon mutants of interest in the GraRS two-component system and a putative inositol monophosphatase were confirmed in a flow cell biofilm model, genetically complemented, and further verified in a community-associated methicillin-resistant S. aureus (CA-MRSA) isolate. Collectively, our screen for biofilm defective mutants identified novel loci involved in S. aureus biofilm formation and underscored the importance of extracellular protease activity and autolysis in biofilm development. PMID:20418950

  7. Identification of genes involved in polysaccharide-independent Staphylococcus aureus biofilm formation.

    Directory of Open Access Journals (Sweden)

    Blaise R Boles

    2010-04-01

    Full Text Available Staphylococcus aureus is a potent biofilm former on host tissue and medical implants, and biofilm growth is a critical virulence determinant for chronic infections. Recent studies suggest that many clinical isolates form polysaccharide-independent biofilms. However, a systematic screen for defective mutants has not been performed to identify factors important for biofilm formation in these strains. We created a library of 14,880 mariner transposon mutants in a S. aureus strain that generates a proteinaceous and extracellular DNA based biofilm matrix. The library was screened for biofilm defects and 31 transposon mutants conferred a reproducible phenotype. In the pool, 16 mutants overproduced extracellular proteases and the protease inhibitor alpha(2-macroglobulin restored biofilm capacity to 13 of these mutants. The other 15 mutants in the pool displayed normal protease levels and had defects in genes involved in autolysis, osmoregulation, or uncharacterized membrane proteins. Two transposon mutants of interest in the GraRS two-component system and a putative inositol monophosphatase were confirmed in a flow cell biofilm model, genetically complemented, and further verified in a community-associated methicillin-resistant S. aureus (CA-MRSA isolate. Collectively, our screen for biofilm defective mutants identified novel loci involved in S. aureus biofilm formation and underscored the importance of extracellular protease activity and autolysis in biofilm development.

  8. DNA-microarrays identification of Streptococcus mutans genes associated with biofilm thickness

    Directory of Open Access Journals (Sweden)

    Feldman Mark

    2008-12-01

    Full Text Available Abstract Background A biofilm is a complex community of microorganisms that develop on surfaces in diverse environments. The thickness of the biofilm plays a crucial role in the physiology of the immobilized bacteria. The most cariogenic bacteria, mutans streptococci, are common inhabitants of a dental biofilm community. In this study, DNA-microarray analysis was used to identify differentially expressed genes associated with the thickness of S. mutans biofilms. Results Comparative transcriptome analyses indicated that expression of 29 genes was differentially altered in 400- vs. 100-microns depth and 39 genes in 200- vs. 100-microns biofilms. Only 10 S. mutans genes showed differential expression in both 400- vs. 100-microns and 200- vs. 100-microns biofilms. All of these genes were upregulated. As sucrose is a predominant factor in oral biofilm development, its influence was evaluated on selected genes expression in the various depths of biofilms. The presence of sucrose did not noticeably change the regulation of these genes in 400- vs. 100-microns and/or 200- vs. 100-microns biofilms tested by real-time RT-PCR. Furthermore, we analyzed the expression profile of selected biofilm thickness associated genes in the luxS- mutant strain. The expression of those genes was not radically changed in the mutant strain compared to wild-type bacteria in planktonic condition. Only slight downregulation was recorded in SMU.2146c, SMU.574, SMU.609, and SMU.987 genes expression in luxS- bacteria in biofilm vs. planktonic environments. Conclusion These findings reveal genes associated with the thickness of biofilms of S. mutans. Expression of these genes is apparently not regulated directly by luxS and is not necessarily influenced by the presence of sucrose in the growth media.

  9. Consensus guidelines for the identification and treatment of biofilms in chronic nonhealing wounds

    DEFF Research Database (Denmark)

    Schultz, Gregory; Bjarnsholt, Thomas; James, Garth A.

    2017-01-01

    diagnostic options; clinical indicators of biofilms; future options for diagnostic tests; treatment strategies; mechanical debridement; topical antiseptics; screening antibiofilm agents; and levels of evidence when choosing antibiofilm treatments. Conclusion: This consensus document attempts to clarify...... misunderstandings about the role of biofilms in clinical practice, and provides a basis for clinicians to recognize biofilms in chronic nonhealing wounds and manage patients optimally. A new paradigm for wound care, based on a stepped-down treatment approach, was derived from the consensus statements....

  10. Isolation and identification of bacteria able to form biofilms from deep subsurface environments

    International Nuclear Information System (INIS)

    Sakurai, Kenta; Yoshikawa, Hideki

    2012-01-01

    Migration radionuclides in an underground environment are one of the major concerns in the safety assessment of a geological repository. Biofilms can have an impact on the transport of radionuclides in several ways: (1) by acting as a barrier to radionuclide sorption onto geological surfaces, or (2) by providing a sorption site for radionuclides, or (3) by trapping many things, including radionuclides. Little is known about bacterial effects on the biofilm formation deep underground. In this study, we isolated bacterial strains from deep groundwater and evaluated the biofilm formation abilities of these strains by crystal violet assay. Bacterial strains were isolated from ground-water collected at -140 m in the 07-V140-M01 borehole at the Horonobe Underground Research Center, Japan. The crystal violet assay showed that 98% of the isolated strains had biofilm formation abilities under tested conditions. This result suggested that biofilm formation must not be neglected in the study of migration radionuclides in nuclear waste repositories. The isolated strains produced differential amounts of biofilm, although they were identified as the same Pseudomonas species, suggesting that biofilm formation abilities varied at different strain levels. These results support the conclusion that the assessment of biofilm impact on the transport of radionuclides in a geological repository must consider the variation in biofilm formation as a function of strain level. (author)

  11. Identification of Candida albicans by using different culture medias and its association in potentially malignant and malignant lesions.

    Science.gov (United States)

    Saigal, Sonal; Bhargava, Ankur; Mehra, S K; Dakwala, Falguni

    2011-07-01

    The present study evaluates the association of Candida albicans with normal control group, potentially malignant and malignant lesions of oral cavity by using two different liquid culture media. Saliva was collected and biopsy was taken only from those clinically suspected potentially malignant and malignant lesions for histopathological diagnosis. Saliva samples were inoculated for fungal growth in Sabouraud's dextrose agar and culture-positive samples had undergone for Germ tube test. Germ tube-positive samples were further taken for quantification of chlamydospore production in liquid media at 8 and 16 hours. In normal control groups no fungus growth was found; however, potentially malignant and malignant cases showed fungus growth, positive germ tube test and chlamydospore formation. The result also showed rapid and quantitatively more chlamydospore formation in corn meal broth + 5% milk in comparison to serum milk culture media. The oral mucosa is compromised in potentially malignant lesions, it can be argued that this species may be involved in carcinogenesis by elaborating the nitrosamine compounds which either act directly on oral mucosa or interact with other chemical carcinogens to activate specific proto-oncogenes and thereby initiate oral neoplasia.

  12. Identification of Candida albicans by using different culture medias and its association in potentially malignant and malignant lesions

    Directory of Open Access Journals (Sweden)

    Sonal Saigal

    2011-01-01

    Full Text Available Background and Objective: The present study evaluates the association of Candida albicans with normal control group, potentially malignant and malignant lesions of oral cavity by using two different liquid culture media. Materials and Methods: Saliva was collected and biopsy was taken only from those clinically suspected potentially malignant and malignant lesions for histopathological diagnosis. Saliva samples were inoculated for fungal growth in Sabouraud′s dextrose agar and culture-positive samples had undergone for Germ tube test. Germ tube-positive samples were further taken for quantification of chlamydospore production in liquid media at 8 and 16 hours. Results: In normal control groups no fungus growth was found; however, potentially malignant and malignant cases showed fungus growth, positive germ tube test and chlamydospore formation. The result also showed rapid and quantitatively more chlamydospore formation in corn meal broth + 5% milk in comparison to serum milk culture media. Conclusion: The oral mucosa is compromised in potentially malignant lesions, it can be argued that this species may be involved in carcinogenesis by elaborating the nitrosamine compounds which either act directly on oral mucosa or interact with other chemical carcinogens to activate specific proto-oncogenes and thereby initiate oral neoplasia.

  13. Identification of the Genes Involved in the Biofilm-like Structures on Actinomyces oris K20, a Clinical Isolate from an Apical Lesion

    Science.gov (United States)

    2013-01-01

    bacteria in clinically asymptomatic periapical pathosis. J Endod 1990;16:534–8. 5. Nair PNR. On the causes of persistent apical periodontitis : a review...Identification of the Genes Involved in the Biofilm-like Structures on Actinomyces oris K20, a Clinical Isolate from an Apical Lesion Chiho Mashimo...Actinomyces oris K20. (J Endod 2013;39:44–48) Key Words Actinomyces oris, apical abscess, biofilm, polysac- charide deacetylase, transposon mutagenesis

  14. 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...

  15. In Situ Identification and Stratification of Monochloramine Inhibition Effects on Nitrifying Biofilms as Determined by the Use of Microelectrodes

    Science.gov (United States)

    The nitrifying biofilm grown in an annular biofilm reactor and the microbial deactivation achieved after monochloramine treatment were investigated using microelectrodes. The nitrifying biofilm ammonium microprofile was measured and the effect of monochloramine on nitrifying bio...

  16. Affirm VPIII microbial identification test can be used to detect gardnerella vaginalis, Candida albicans and trichomonas vaginalis microbial infections in Korean women.

    Science.gov (United States)

    Byun, Seung Won; Park, Yeon Joon; Hur, Soo Young

    2016-04-01

    The aim of this study was to compare Affirm VPIII Microbial Identification Test results for Korean women to those obtained for Gardnerella vaginalis through Nugent score, Candida albicans based on vaginal culture and Trichomonas vaginalis based on wet smear diagnostic standards. Study participants included 195 women with symptomatic or asymptomatic vulvovaginitis under hospital obstetric or gynecologic care. A definite diagnosis was made based on Nugent score for Gardnerella, vaginal culture for Candida and wet prep for Trichomonas vaginalis. Affirm VPIII Microbial Identification Test results were then compared to diagnostic standard results. Of the 195 participants, 152 were symptomatic, while 43 were asymptomatic. Final diagnosis revealed 68 (37.87%) cases of Gardnerella, 29 (14.87%) cases of Candida, one (0.51%) case of Trichomonas, and 10 (5.10%) cases of mixed infections. The detection rates achieved by each detection method (Affirm assay vs diagnostic standard) for Gardnerella and Candida were not significantly different (33.33% vs 34.8% for Gardnerella, 13.33% vs 14.87% for Candida, respectively). The sensitivity and specificity of the Affirm test for Gardnerella compared to the diagnostic standard were 75.0% and 88.98%, respectively. For Candida, the sensitivity and specificity of the Affirm test compared to the diagnostic standard were 82.76% and 98.80%, respectively. The number of Trichomonas cases was too small (1 case) to be statistically analyzed. The Affirm test is a quick tool that can help physicians diagnose and treat patients with infectious vaginitis at the point of care. © 2016 Japan Society of Obstetrics and Gynecology.

  17. Rapid and reliable MALDI-TOF mass spectrometry identification of Candida non-albicans isolates from bloodstream infections.

    Science.gov (United States)

    Pulcrano, Giovanna; Iula, Dora Vita; Vollaro, Antonio; Tucci, Alessandra; Cerullo, Monica; Esposito, Matilde; Rossano, Fabio; Catania, Maria Rosaria

    2013-09-01

    Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) fingerprinting has recently become an effective instrument for rapid microbiological diagnostics and in particular for identification of micro-organisms directly in a positive blood culture. The aim of the study was to evaluate a collection of 82 stored yeast isolates from bloodstream infection, by MALDI-TOF MS; 21 isolates were identified also directly from positive blood cultures and in the presence of other co-infecting micro-organisms. Of the 82 isolates grown on plates, 64 (76%) were correctly identified by the Vitek II system and 82 (100%) by MALDI-TOF MS; when the two methods gave different results, the isolate was identified by PCR. MALDI-TOF MS was unreliable in identifying two isolates (Candida glabrata and Candida parapsilosis) directly from blood culture; however, direct analysis from positive blood culture samples was fast and effective for the identification of yeast, which is of great importance for early and adequate treatment. © 2013. Published by Elsevier B.V. All rights reserved.

  18. Candida biofilms: is adhesion sexy?

    Science.gov (United States)

    Soll, David R

    2008-08-26

    The development of Candida albicans biofilms requires two types of adhesion molecule - the Als proteins and Hwp1. Mutational analyses have recently revealed that these molecules play complementary roles, and their characteristics suggest that they may have evolved from primitive mating agglutinins.

  19. Streptococcus mutans competence-stimulating peptide inhibits Candida albicans hypha formation

    NARCIS (Netherlands)

    Jarosz, L.M.; Deng, D.M.; van der Mei, H.C.; Crielaard, W.; Krom, B.P.

    2009-01-01

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

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  1. Identification of bacterial strains isolated from the Mediterranean Sea exhibiting different abilities of biofilm formation.

    Science.gov (United States)

    Brian-Jaisson, Florence; Ortalo-Magné, Annick; Guentas-Dombrowsky, Linda; Armougom, Fabrice; Blache, Yves; Molmeret, Maëlle

    2014-07-01

    The Mediterranean Sea has rarely been investigated for the characterization of marine bacteria as compared to other marine environments such as the Atlantic or Pacific Ocean. Bacteria recovered from inert surfaces are poorly studied in these environments, when it has been shown that the community structure of attached bacteria can be dissimilar from that of planktonic bacteria present in the water column. The objectives of this study were to identify and characterize marine bacteria isolated from biofilms developed on inert surfaces immersed in the Mediterranean Sea and to evaluate their capacity to form a biofilm in vitro. Here, 13 marine bacterial strains have been isolated from different supports immersed in seawater in the Bay of Toulon (France). Phylogenetic analysis and different biological and physico-chemical properties have been investigated. Among the 13 strains recovered, 8 different genera and 12 different species were identified including 2 isolates of a novel bacterial species that we named Persicivirga mediterranea and whose genus had never been isolated from the Mediterranean Sea. Shewanella sp. and Pseudoalteromonas sp. were the most preponderant genera recovered in our conditions. The phenotypical characterization revealed that one isolate belonging to the Polaribacter genus differed from all the other ones by its hydrophobic properties and poor ability to form biofilms in vitro. Identifying and characterizing species isolated from seawater including from Mediterranean ecosystems could be helpful for example, to understand some aspects of bacterial biodiversity and to further study the mechanisms of biofilm (and biofouling) development in conditions approaching those of the marine environment.

  2. Dynamics of Mixed- Candida Species Biofilms in Response to Antifungals.

    Science.gov (United States)

    Vipulanandan, G; Herrera, M; Wiederhold, N P; Li, X; Mintz, J; Wickes, B L; Kadosh, D

    2018-01-01

    Oral infections caused by Candida species, the most commonly isolated human fungal pathogen, are frequently associated with biofilms. Although Candida albicans is the predominant organism found in patients with oral thrush, a biofilm infection, there is an increasing incidence of oral colonization and infections caused by non- albicans Candida species, including C. glabrata, C. dubliniensis, and C. tropicalis, which are frequently more resistant to antifungal treatment. While single-species Candida biofilms have been well studied, considerably less is known about the dynamics of mixed- Candida species biofilms and how these dynamics are altered by antifungal treatment. To address these questions, we developed a quantitative polymerase chain reaction-based approach to determine the precise species composition of mixed- Candida species biofilms formed by clinical isolates and laboratory strains in the presence and absence of clinically relevant concentrations of 3 commonly used antifungals: fluconazole, caspofungin, and amphotericin B. In monospecies biofilms, fluconazole exposure favored growth of C. glabrata and C. tropicalis, while caspofungin generally favored significant growth of all species to a varying degree. Fluconazole was not effective against preformed mixed- Candida species biofilms while amphotericin B was potent. As a general trend, in mixed- Candida species biofilms, C. albicans lost dominance in the presence of antifungals. Interestingly, presence in mixed versus monospecies biofilms reduced susceptibility to amphotericin B for C. tropicalis and C. glabrata. Overall, our data suggest that antifungal treatment favors the growth of specific non- albicans Candida species in mixed- Candida species biofilms.

  3. Molecular identification, antifungal susceptibility profile, and biofilm formation of clinical and environmental Rhodotorula species isolates.

    Science.gov (United States)

    Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona E; Colombo, Arnaldo Lopes

    2013-01-01

    Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC(50)/MIC(90), 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula

  4. Development of Anti-Virulence Approaches for Candidiasis via a Novel Series of Small-Molecule Inhibitors of Candida albicans Filamentation

    Directory of Open Access Journals (Sweden)

    Jesus A. Romo

    2017-12-01

    Full Text Available Candida albicans remains the main etiologic agent of candidiasis, the most common fungal infection and now the third most frequent infection in U.S. hospitals. The scarcity of antifungal agents and their limited efficacy contribute to the unacceptably high morbidity and mortality rates associated with these infections. The yeast-to-hypha transition represents the main virulence factor associated with the pathogenesis of C. albicans infections. In addition, filamentation is pivotal for robust biofilm development, which represents another major virulence factor for candidiasis and further complicates treatment. Targeting pathogenic mechanisms rather than growth represents an attractive yet clinically unexploited approach in the development of novel antifungal agents. Here, we performed large-scale phenotypic screening assays with 30,000 drug-like small-molecule compounds within ChemBridge’s DIVERSet chemical library in order to identify small-molecule inhibitors of C. albicans filamentation, and our efforts led to the identification of a novel series of bioactive compounds with a common biaryl amide core structure. The leading compound of this series, N-[3-(allyloxy-phenyl]-4-methoxybenzamide, was able to prevent filamentation under all liquid and solid medium conditions tested, suggesting that it impacts a common core component of the cellular machinery that mediates hypha formation under different environmental conditions. In addition to filamentation, this compound also inhibited C. albicans biofilm formation. This leading compound also demonstrated in vivo activity in clinically relevant murine models of invasive and oral candidiasis. Overall, our results indicate that compounds within this series represent promising candidates for the development of novel anti-virulence approaches to combat C. albicans infections.

  5. The potential of Raman spectroscopy for the identification of biofilm formation by Staphylococcus epidermidis

    Czech Academy of Sciences Publication Activity Database

    Samek, Ota; Al-Marashi, J.F.M.; Telle, H.H.

    2010-01-01

    Roč. 7, č. 5 (2010), s. 378-383 ISSN 1612-2011 R&D Projects: GA MŠk OC08034 Grant - others:EC(XE) MEIF-CT-2006-041965 Institutional research plan: CEZ:AV0Z20650511 Keywords : Raman spectroscopy * Staphylococcus epidermidis * biofilm * principle component analysis Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 6.010, year: 2010

  6. Identification of pink-pigmented bacteria isolated from environmental water samples and their biofilm formation abilities.

    Science.gov (United States)

    Furuhata, Katsunori; Kato, Yuko; Goto, Keiichi; Saitou, Keiko; Sugiyama, Jun-Ichi; Hara, Motonobu; Fukuyama, Masahumi

    2008-06-01

    Sixty-seven strains of pink-pigmented bacteria, which were isolated from environmental water samples collected nationwide, were identified by partial 16S rDNA sequence analysis. In addition, the biofilm formation ability of the isolates was experimentally investigated. We could identify only 2 strains at the species level: Pedobacter roseus HS-38 and Runella slithyformis HS-77. The results showed that of the strains tested, 22 strains (32.8%) were Pedobacter spp., which was most frequently identified, followed by 19 strains (28.4%) of Arcicella spp., 16 strains (23.9%) of Deinococcus spp., 5 strains (7.5%) of Roseomonas spp., 4 strains (6.0%) of Flectobacillus spp. and 1 strain (1.5%) of Runella sp. Most isolates showed low similarity values to previously known species, and they were found to be novel species. At a result, it was difficult to identify environmental water-derived pink-pigmented bacteria at the species level. On the other hand, when we measured the absorbance by the crystal violet staining to examine the quantities of biofilm formation of these strains, fifty-five (82.0%) of the 67 isolates formed biofilm. The absorbance of Deinococcus sp. HS-75 was the highest (3.56). When comparing the absorbance values among the genera, Roseomonas spp. showed the highest absorbance (mean:1.62), followed by Deinococcus spp. (mean: 1.03), and Arcicella spp. (mean: 1.01). Strains of Flectobacillus spp. (mean: 0.48) and Pedobacter spp. (mean: 0.42) showed lower absorbance values. As above, it was shown that, at the species level, the pink-pigmented bacteria in the water in the Japanese environment had various levels of ability to form biofilm.

  7. Identification of individual biofilm-forming bacterial cells using Raman tweezers

    Czech Academy of Sciences Publication Activity Database

    Samek, Ota; Bernatová, Silvie; Ježek, Jan; Šiler, Martin; Šerý, Mojmír; Krzyžánek, Vladislav; Hrubanová, Kamila; Zemánek, Pavel; Holá, V.; Růžička, F.

    2015-01-01

    Roč. 20, č. 5 (2015), 051038:1-6 ISSN 1083-3668 R&D Projects: GA ČR GAP205/11/1687; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : Raman tweezers * Staphylococcus epidermidis * biofilm Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.556, year: 2015

  8. On the chemical identification and visualization of uranium species in biofilms and Euglena mutabilis cells

    International Nuclear Information System (INIS)

    Brockmann, Sina

    2013-01-01

    For risk assessment of anthropogenic uranium contaminations in the environment a detailed knowledge of the migration and immobilization behavior is required to prevent health hazards for humans and animals caused by an uncontrolled discharge of uranium. Hence, comprehensive studies on the interactions of uranium with the environment are required. Besides the influences of the geological materials, there is a huge effect of the biosphere, especially the interactions with microorganisms and biofilms, on the properties of uranium in the environment. The aim of this study was to investigate and to describe naturally occurring biofilms from real uranium contaminated areas and their influence on the uranium migration. The investigations in this study on the localization and the speciation of the uranium in the biosystems were primarily done with a coupled system of laser scanning microscopy (CLSM) and laser induced fluorescence spectroscopy (LIFS). Natural biofilms collected from two uranium contaminated acid mine drainage (AMD) environments, the former uranium mine in Koenigstein (Saxony, Germany) and the former Gessenheap near Ronneburg (Thuringia,Germany), were investigated in this study. The chosen samples represent typical biofilm communities living in AMD water and are exemplary for potentially occurring scenarios of contaminated mining water both in the underground and on the surface. The investigation on the interactions between uranium and Euglena mutabilis, which is a typical unicellular microorganism that can be found in acidic, uranium and other heavy metal containing waters, was another important part of this study. Bioaccumulation experiments of uranium on living Euglena mutabilis cells depending on the pH (pH 3 - 6) and on the background media in sodium perchlorate (9 g/l) or sodium sulfate (3.48 g/l) solution containing 0.01 mM uranium show an effective immobilization of uranium. At the acidic pH-values (pH 3 - 4) over 90 % of the added uranium was

  9. Identification of Streptococcus sanguinis Genes Required for Biofilm Formation and Examination of Their Role in Endocarditis Virulence▿

    OpenAIRE

    Ge, Xiuchun; Kitten, Todd; Chen, Zhenming; Lee, Sehmi P.; Munro, Cindy L.; Xu, Ping

    2008-01-01

    Streptococcus sanguinis is one of the pioneers in the bacterial colonization of teeth and is one of the most abundant species in the oral biofilm called dental plaque. S. sanguinis is also the most common viridans group streptococcal species implicated in infective endocarditis. To investigate the association of biofilm and endocarditis, we established a biofilm assay and examined biofilm formation with a signature-tagged mutagenesis library of S. sanguinis. Four genes that have not previousl...

  10. Identification of Bicarbonate as a Trigger and Genes Involved with Extracellular DNA Export in Mycobacterial Biofilms

    Directory of Open Access Journals (Sweden)

    Sasha J. Rose

    2016-12-01

    Full Text Available Extracellular DNA (eDNA is an integral biofilm matrix component of numerous pathogens, including nontuberculous mycobacteria (NTM. Cell lysis is the source of eDNA in certain bacteria, but the source of eDNA remains unidentified for NTM, as well as for other eDNA-containing bacterial species. In this study, conditions affecting eDNA export were examined, and genes involved with the eDNA export mechanism were identified. After a method for monitoring eDNA in real time in undisturbed biofilms was established, different conditions affecting eDNA were investigated. Bicarbonate positively influenced eDNA export in a pH-independent manner in Mycobacterium avium, M. abscessus, and M. chelonae. The surface-exposed proteome of M. avium in eDNA-containing biofilms revealed abundant carbonic anhydrases. Chemical inhibition of carbonic anhydrases with ethoxzolamide significantly reduced eDNA export. An unbiased transposon mutant library screen for eDNA export in M. avium identified many severely eDNA-attenuated mutants, including one not expressing a unique FtsK/SpoIIIE-like DNA-transporting pore, two with inactivation of carbonic anhydrases, and nine with inactivation of genes belonging to a unique genomic region, as well as numerous mutants involved in metabolism and energy production. Complementation of nine mutants that included the FtsK/SpoIIIE and carbonic anhydrase significantly restored eDNA export. Interestingly, several attenuated eDNA mutants have mutations in genes encoding proteins that were found with the surface proteomics, and many more mutations are localized in operons potentially encoding surface proteins. Collectively, our data strengthen the evidence of eDNA export being an active mechanism that is activated by the bacterium responding to bicarbonate.

  11. Identification of lactobacilli with inhibitory effect on biofilm formation by pathogenic bacteria on stainless steel surfaces.

    Science.gov (United States)

    Ait Ouali, Fatma; Al Kassaa, Imad; Cudennec, Benoit; Abdallah, Marwan; Bendali, Farida; Sadoun, Djamila; Chihib, Nour-Eddine; Drider, Djamel

    2014-11-17

    Two hundred and thirty individual clones of microorganisms were recovered from milk tanks and milking machine surfaces at two distinct farms (Bejaja City, Algeria). Of these clones, 130 were identified as lactic acid bacteria (LAB). In addition Escherichia coli, Salmonella, Staphylococcus aureus and Pseudomonas aeruginosa species were identified in the remaining 100 isolates-spoilage isolate. These isolates were assayed for ability to form biofilms. S. aureus, Lactobacillus brevis strains LB1F2, LB14F1 and LB15F1, and Lactobacillus pentosus strains LB2F2 and LB3F2 were identified as the best biofilm formers. Besides, these LAB isolates were able to produce proteinaceous substances with antagonism against the aforementioned spoilage isolates, when grown in MRS or TSB-YE media. During the screening, L. pentosus LB3F2 exhibited the highest antibacterial activity when grown in TSB-YE medium at 30 °C. Additionally, L. pentosus LB3F2 was able to strongly hamper the adhesion of S. aureus SA3 on abiotic surfaces as polystyrene and stainless steel slides. LAB isolates did not show any hemolytic activity and all of them were sensitive to different families of antibiotic tested. It should be pointed out that LB3F2 isolate was not cytotoxic on the intestinal cells but could stimulate their metabolic activity. This report unveiled the potential of LB1F2, LB14F1, LB15F1, LB2F2, and LB3F2 isolates to be used as natural barrier or competitive exclusion organism in the food processing sector as well as a positive biofilm forming bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. EFEITO ANTIFÚNGICO DO RESVERATROL SOBRE A CANDIDA ALBICANS

    Directory of Open Access Journals (Sweden)

    Bruna Graziele Marques da Silva

    2017-05-01

    Full Text Available A Candida albicans é um fungo comensal da microbiota normal, sendo capaz de produzir infecções em pacientes imunocomprometidos. As infecções estão apresentando resistência às terapias convencionais. Recentemente diversos compostos derivados de produtos naturais vêm sendo testados, destacando o polifenol Resveratrol que possui efeitos farmacológicos. Desse modo o objetivo deste estudo foi avaliar os efeitos do polifenol sobre o crescimento e a viabilidade do biofilme da C. albicans. Foram utilizadas as concentrações do Resveratrol em 5 μΜ, 10 μΜ, 20 μΜ, 50 μΜ, 100 μΜ, 200 μΜ, 300μΜ, 400μΜ e 500μΜ e a densidade de C.albicans foram de 105, 106 e 107 células viáveis/ml, e ainda, foi analisada a morfologia. Os resultados obtidos demonstram maior inibição no crescimento e viabilidade do biofilme na concentração de 500μΜ de polifenol, em comparação ao controle. Dessa forma, o polifenol Resveratrol foi capaz de alterar a morfologia das células e reduzir a viabilidade do biofilme da Candida albicans.

  13. Streptococcus mutans competence-stimulating peptide inhibits Candida albicans hypha formation.

    Science.gov (United States)

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

    2009-11-01

    The oral cavity is colonized by microorganisms growing in biofilms in which interspecies interactions take place. Streptococcus mutans grows in biofilms on enamel surfaces and is considered one of the main etiological agents of human dental caries. Candida albicans is also commonly found in the human oral cavity, where it interacts with S. mutans. C. albicans is a polymorphic fungus, and the yeast-to-hypha transition is involved in virulence and biofilm formation. The aim of this study was to investigate interkingdom communication between C. albicans and S. mutans based on the production of secreted molecules. S. mutans UA159 inhibited C. albicans germ tube (GT) formation in cocultures even when physically separated from C. albicans. Only S. mutans spent medium collected in the early exponential phase (4-h-old cultures) inhibited the GT formation of C. albicans. During this phase, S. mutans UA159 produces a quorum-sensing molecule, competence-stimulating peptide (CSP). The role of CSP in inhibiting GT formation was confirmed by using synthetic CSP and a comC deletion strain of S. mutans UA159, which lacks the ability to produce CSP. Other S. mutans strains and other Streptococcus spp. also inhibited GT formation but to different extents, possibly reflecting differences in CSP amino acid sequences among Streptococcus spp. or differences in CSP accumulation in the media. In conclusion, CSP, an S. mutans quorum-sensing molecule secreted during the early stages of growth, inhibits the C. albicans morphological switch.

  14. Comparative Phenotypic Analysis of the Major Fungal Pathogens Candida parapsilosis and Candida albicans

    Science.gov (United States)

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

    2014-01-01

    Candida parapsilosis and Candida albicans are human fungal pathogens that belong to the CTG clade in the Saccharomycotina. In contrast to C. albicans, relatively little is known about the virulence properties of C. parapsilosis, a pathogen particularly associated with infections of premature neonates. We describe here the construction of C. parapsilosis strains carrying double allele deletions of 100 transcription factors, protein kinases and species-specific genes. Two independent deletions were constructed for each target gene. Growth in >40 conditions was tested, including carbon source, temperature, and the presence of antifungal drugs. The phenotypes were compared to C. albicans strains with deletions of orthologous transcription factors. We found that many phenotypes are shared between the two species, such as the role of Upc2 as a regulator of azole resistance, and of CAP1 in the oxidative stress response. Others are unique to one species. For example, Cph2 plays a role in the hypoxic response in C. parapsilosis but not in C. albicans. We found extensive divergence between the biofilm regulators of the two species. We identified seven transcription factors and one protein kinase that are required for biofilm development in C. parapsilosis. Only three (Efg1, Bcr1 and Ace2) have similar effects on C. albicans biofilms, whereas Cph2, Czf1, Gzf3 and Ume6 have major roles in C. parapsilosis only. Two transcription factors (Brg1 and Tec1) with well-characterized roles in biofilm formation in C. albicans do not have the same function in C. parapsilosis. We also compared the transcription profile of C. parapsilosis and C. albicans biofilms. Our analysis suggests the processes shared between the two species are predominantly metabolic, and that Cph2 and Bcr1 are major biofilm regulators in C. parapsilosis. PMID:25233198

  15. Sexual Biofilm Formation in Candida tropicalis Opaque Cells

    Science.gov (United States)

    Jones, Stephen K.; Hirakawa, Matthew P.; Bennett, Richard J.

    2014-01-01

    Summary Candida albicans and Candida tropicalis are opportunistic fungal pathogens that can transition between white and opaque phenotypic states. White and opaque cells differ both morphologically and in their responses to environmental signals. In C. albicans, opaque cells respond to sexual pheromones by undergoing conjugation, while white cells are induced by pheromones to form sexual biofilms. Here, we show that sexual biofilm formation also occurs in C. tropicalis but, unlike C. albicans, biofilms are formed exclusively by opaque cells. C. tropicalis biofilm formation was dependent on the pheromone receptors Ste2 and Ste3, confirming the role of pheromone signaling in sexual biofilm development. Structural analysis of C. tropicalis sexual biofilms revealed stratified communities consisting of a basal layer of yeast cells and an upper layer of filamentous cells, together with an extracellular matrix. Transcriptional profiling showed that genes involved in pheromone signaling and conjugation were upregulated in sexual biofilms. Furthermore, FGR23, which encodes an agglutinin-like protein, was found to enhance both mating and sexual biofilm formation. Together, these studies reveal that C. tropicalis opaque cells form sexual biofilms with a complex architecture, and suggest a conserved role for sexual agglutinins in mediating mating, cell cohesion and biofilm formation. PMID:24612417

  16. Identification of Streptococcus sanguinis Genes Required for Biofilm Formation and Examination of Their Role in Endocarditis Virulence▿

    Science.gov (United States)

    Ge, Xiuchun; Kitten, Todd; Chen, Zhenming; Lee, Sehmi P.; Munro, Cindy L.; Xu, Ping

    2008-01-01

    Streptococcus sanguinis is one of the pioneers in the bacterial colonization of teeth and is one of the most abundant species in the oral biofilm called dental plaque. S. sanguinis is also the most common viridans group streptococcal species implicated in infective endocarditis. To investigate the association of biofilm and endocarditis, we established a biofilm assay and examined biofilm formation with a signature-tagged mutagenesis library of S. sanguinis. Four genes that have not previously been associated with biofilm formation in any other bacterium, purB, purL, thrB, and pyrE, were putatively identified as contributing to in vitro biofilm formation in S. sanguinis. By examining 800 mutants for attenuation in the rabbit endocarditis model and for reduction in biofilm formation in vitro, we found some mutants that were both biofilm defective and attenuated for endocarditis. However, we also identified mutants with only reduced biofilm formation or with only attenuation in the endocarditis model. This result indicates that the ability to form biofilms in vitro is not associated with endocarditis virulence in vivo in S. sanguinis. PMID:18390999

  17. Identification of Streptococcus sanguinis genes required for biofilm formation and examination of their role in endocarditis virulence.

    Science.gov (United States)

    Ge, Xiuchun; Kitten, Todd; Chen, Zhenming; Lee, Sehmi P; Munro, Cindy L; Xu, Ping

    2008-06-01

    Streptococcus sanguinis is one of the pioneers in the bacterial colonization of teeth and is one of the most abundant species in the oral biofilm called dental plaque. S. sanguinis is also the most common viridans group streptococcal species implicated in infective endocarditis. To investigate the association of biofilm and endocarditis, we established a biofilm assay and examined biofilm formation with a signature-tagged mutagenesis library of S. sanguinis. Four genes that have not previously been associated with biofilm formation in any other bacterium, purB, purL, thrB, and pyrE, were putatively identified as contributing to in vitro biofilm formation in S. sanguinis. By examining 800 mutants for attenuation in the rabbit endocarditis model and for reduction in biofilm formation in vitro, we found some mutants that were both biofilm defective and attenuated for endocarditis. However, we also identified mutants with only reduced biofilm formation or with only attenuation in the endocarditis model. This result indicates that the ability to form biofilms in vitro is not associated with endocarditis virulence in vivo in S. sanguinis.

  18. Inhibitory effects of Lactobacillus rhamnosus and Lactobacillus casei on Candida biofilm of denture surface.

    Science.gov (United States)

    Song, Young-Gyun; Lee, Sung-Hoon

    2017-04-01

    Candida albicans biofilm is associated with denture-related stomatitis and oral candidiasis of elderly. Probiotics are beneficial bacteria and have antibacterial activity against pathogenic bacteria. The purpose of this study was to investigate the antifungal activity of various probiotics against C. albicans and the inhibitory effects of probiotics on Candida biofilm on the denture surface. The spent culture media of various probiotics were investigated the antifungal efficacy against C. albicans. Candida biofilm was formed on a denture base resin and was then treated with Lactobacillus rhamnosus and Lactobacillus casei. Also, the biofilms of L. rhamnosus and L. casei were formed and were sequentially treated with C. albicans. Colony-forming units of C. albicans on the denture surface were counted after spreading on agar plate. The denture base resin was treated with the spent culture media for 30days, after which the denture surface roughness was analyzed with an atomic force microscope. L. rhamnosus and L. casei exhibited stronger antifungal activity than other probiotics. The spent culture medium of L. rhamnosus and L. casei exhibited the antifungal activity against blastoconidia and biofilm of C. albicans. L. rhamnosus and L. casei showed the antifungal activity against Candida biofilm, and the biofilm of L. rhamnosus and L. casei inhibited formation of Candida biofilm on denture surface. Neither of the probiotics affected the surface roughness of the denture base resin. L. rhamnosus and L. casei may be the ideal probiotics for the prevention and treatment of denture-related stomatitis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Portrait of Candida Species Biofilm Regulatory Network Genes.

    Science.gov (United States)

    Araújo, Daniela; Henriques, Mariana; Silva, Sónia

    2017-01-01

    Most cases of candidiasis have been attributed to Candida albicans, but Candida glabrata, Candida parapsilosis and Candida tropicalis, designated as non-C. albicans Candida (NCAC), have been identified as frequent human pathogens. Moreover, Candida biofilms are an escalating clinical problem associated with significant rates of mortality. Biofilms have distinct developmental phases, including adhesion/colonisation, maturation and dispersal, controlled by complex regulatory networks. This review discusses recent advances regarding Candida species biofilm regulatory network genes, which are key components for candidiasis. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Ria Puspitawati

    2011-06-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Candida albicans importance to denture wearers. A literature review.

    Science.gov (United States)

    Gleiznys, Alvydas; Zdanavičienė, Eglė; Žilinskas, Juozas

    2015-01-01

    Opportunistic oral fungal infections have spred, especially in denture wearers. Denture stomatitis is a common inflammatory reaction, multifactorial etiology, which is usually associated with Candida species, particularly Candida albicans, due to its high virulence, ability to adhere and form biofilms on oral cavity tissues and denture surfaces. This article highlights the pathogenesis, clinical presentation, and management strategies of Candida-associated denture stomatitis commonly encountered in dental practice.

  3. Identification of GIG1, a GlcNAc-Induced Gene in Candida albicans Needed for Normal Sensitivity to the Chitin Synthase Inhibitor Nikkomycin Z▿§

    OpenAIRE

    Gunasekera, Angelo; Alvarez, Francisco J.; Douglas, Lois M.; Wang, Hong X.; Rosebrock, Adam P.; Konopka, James B.

    2010-01-01

    The amino sugar N-acetylglucosamine (GlcNAc) is known to be an important structural component of cells from bacteria to humans, but its roles in cell signaling are less well understood. GlcNAc induces two pathways in the human fungal pathogen Candida albicans. One activates cyclic AMP (cAMP) signaling, which stimulates the formation of hyphal cells and the expression of virulence genes, and the other pathway induces genes needed to catabolize GlcNAc. Microarray analysis of gene expression was...

  4. Combating biofilms

    DEFF Research Database (Denmark)

    Yang, Liang; Liu, Yang; Wu, Hong

    2012-01-01

    Biofilms are complex microbial communities consisting of microcolonies embedded in a matrix of self-produced polymer substances. Biofilm cells show much greater resistance to environmental challenges including antimicrobial agents than their free-living counterparts. The biofilm mode of life...... is believed to significantly contribute to successful microbial survival in hostile environments. Conventional treatment, disinfection and cleaning strategies do not proficiently deal with biofilm-related problems, such as persistent infections and contamination of food production facilities. In this review......, strategies to control biofilms are discussed, including those of inhibition of microbial attachment, interference of biofilm structure development and differentiation, killing of biofilm cells and induction of biofilm dispersion....

  5. Inhibitory effect of farnesol on biofilm formation by Candida tropicalis

    Directory of Open Access Journals (Sweden)

    E Zibafar

    2009-03-01

    Full Text Available ABSTRACT Background: Candidiasis associated with indwelling medical devices is especially problematic since they can act as substrates for biofilm growth which are highly resistant to antifungal drugs. Farnesol is a quorum-sensing molecule that inhibits filamentation and biofilm formation in Candida albicans. Since in recent years Candida tropicalis have been reported as an important and common non-albicans Candida species with high drug resistance pattern, the inhibitory effect of farnesol on biofilm formation by Candida tropicalis was evaluated. Methods: Five Candida tropicalis strains were treated with different concentration of farnesol (0, 30 and 300 µM after 0, 1 and 4 hrs of adherence and then they were maintained under biofilm formation condition in polystyrene, 96-well microtiter plates at 37°C for 48 hrs. Biofilm formation was measured by a semiquantitative colorimetric technique based on reduction assay of 2,3- bis  -2H-tetrazolium- 5- carboxanilide (XTT. Results: The results indicated that the initial adherence time had no effect on biofilm formation and low concentration of farnesol (30 µM could not inhibit biofilm formation. However the presence of non-adherent cells increased biofilm formation significantly and the high concentration of farnesol (300 µM could inhibit biofilm formation. Conclusion: Results of this study showed that the high concentration of farnesol could inhibit biofilm formation and may be used as an adjuvant in prevention and in therapeutic strategies with antifungal drugs.

  6. Candida Biofilms: Threats, Challenges, and Promising Strategies

    Science.gov (United States)

    Cavalheiro, Mafalda; Teixeira, Miguel Cacho

    2018-01-01

    Candida species are fungal pathogens known for their ability to cause superficial and systemic infections in the human host. These pathogens are able to persist inside the host due to the development of pathogenicity and multidrug resistance traits, often leading to the failure of therapeutic strategies. One specific feature of Candida species pathogenicity is their ability to form biofilms, which protects them from external factors such as host immune system defenses and antifungal drugs. This review focuses on the current threats and challenges when dealing with biofilms formed by Candida albicans, Candida glabrata, Candida tropicalis, and Candida parapsilosis, highlighting the differences between the four species. Biofilm characteristics depend on the ability of each species to produce extracellular polymeric substances (EPS) and display dimorphic growth, but also on the biofilm substratum, carbon source availability and other factors. Additionally, the transcriptional control over processes like adhesion, biofilm formation, filamentation, and EPS production displays great complexity and diversity within pathogenic yeasts of the Candida genus. These differences not only have implications in the persistence of colonization and infections but also on antifungal resistance typically found in Candida biofilm cells, potentiated by EPS, that functions as a barrier to drug diffusion, and by the overexpression of drug resistance transporters. The ability to interact with different species in in vivo Candida biofilms is also a key factor to consider when dealing with this problem. Despite many challenges, the most promising strategies that are currently available or under development to limit biofilm formation or to eradicate mature biofilms are discussed. PMID:29487851

  7. Candida Biofilms: Threats, Challenges, and Promising Strategies.

    Science.gov (United States)

    Cavalheiro, Mafalda; Teixeira, Miguel Cacho

    2018-01-01

    Candida species are fungal pathogens known for their ability to cause superficial and systemic infections in the human host. These pathogens are able to persist inside the host due to the development of pathogenicity and multidrug resistance traits, often leading to the failure of therapeutic strategies. One specific feature of Candida species pathogenicity is their ability to form biofilms, which protects them from external factors such as host immune system defenses and antifungal drugs. This review focuses on the current threats and challenges when dealing with biofilms formed by Candida albicans, Candida glabrata, Candida tropicalis , and Candida parapsilosis , highlighting the differences between the four species. Biofilm characteristics depend on the ability of each species to produce extracellular polymeric substances (EPS) and display dimorphic growth, but also on the biofilm substratum, carbon source availability and other factors. Additionally, the transcriptional control over processes like adhesion, biofilm formation, filamentation, and EPS production displays great complexity and diversity within pathogenic yeasts of the Candida genus. These differences not only have implications in the persistence of colonization and infections but also on antifungal resistance typically found in Candida biofilm cells, potentiated by EPS, that functions as a barrier to drug diffusion, and by the overexpression of drug resistance transporters. The ability to interact with different species in in vivo Candida biofilms is also a key factor to consider when dealing with this problem. Despite many challenges, the most promising strategies that are currently available or under development to limit biofilm formation or to eradicate mature biofilms are discussed.

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

    Science.gov (United States)

    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.

  9. Biofilm Risks

    DEFF Research Database (Denmark)

    Wirtanen, Gun Linnea; Salo, Satu

    2016-01-01

    This chapter on biofilm risks deals with biofilm formation of pathogenic microbes, sampling and detection methods, biofilm removal, and prevention of biofilm formation. Several common pathogens produce sticky and/or slimy structures in which the cells are embedded, that is, biofilms, on various...... surfaces in food processing. Biofilms of common foodborne pathogens are reviewed. The issue of persistent and nonpersistent microbial contamination in food processing is also discussed. It has been shown that biofilms can be difficult to remove and can thus cause severe disinfection and cleaning problems...... in food factories. In the prevention of biofilm formation microbial control in process lines should both limit the number of microbes on surfaces and reduce microbial activity in the process. Thus the hygienic design of process equipment and process lines is important in improving the process hygiene...

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

    Science.gov (United States)

    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.

  11. Salmonella biofilms

    NARCIS (Netherlands)

    Castelijn, G.A.A.

    2013-01-01

    Biofilm formation by Salmonellaspp. is a problem in the food industry, since biofilms may act as a persistent source of product contamination. Therefore the aim of this study was to obtain more insight in the processes involved and the factors contributing to Salmonellabiofilm

  12. Identification of GIG1, a GlcNAc-induced gene in Candida albicans needed for normal sensitivity to the chitin synthase inhibitor nikkomycin Z.

    Science.gov (United States)

    Gunasekera, Angelo; Alvarez, Francisco J; Douglas, Lois M; Wang, Hong X; Rosebrock, Adam P; Konopka, James B

    2010-10-01

    The amino sugar N-acetylglucosamine (GlcNAc) is known to be an important structural component of cells from bacteria to humans, but its roles in cell signaling are less well understood. GlcNAc induces two pathways in the human fungal pathogen Candida albicans. One activates cyclic AMP (cAMP) signaling, which stimulates the formation of hyphal cells and the expression of virulence genes, and the other pathway induces genes needed to catabolize GlcNAc. Microarray analysis of gene expression was carried out under four different conditions in order to characterize the transcriptional changes induced by GlcNAc. The most highly induced genes include those that encode a GlcNAc transporter (NGT1) and the GlcNAc catabolic enzymes (HXK1, DAC1, and NAG1). GlcNAc also activated most of the genes whose expression is increased when cells are triggered with other stimuli to form hyphae. Surprisingly, GlcNAc also induced a subset of genes that are regulated by galactose (GAL1, GAL7, and GAL10), which may be due to cross talk between signaling pathways. A novel GlcNAc-induced gene, GIG1, which is not essential for GlcNAc catabolism or the induction of hyphae, was identified. However, a Gig1-green fluorescent protein (GFP) fusion protein was specifically induced by GlcNAc, and not by other sugars. Gig1-GFP localized to the cytoplasm, where GlcNAc metabolism occurs. Significantly, a gig1Δ mutant displayed increased resistance to nikkomycin Z, which inhibits chitin synthase from converting UDP-GlcNAc into cell wall chitin. Gig1 is highly conserved in fungi, especially those that contain GlcNAc catabolic genes. These results implicate Gig1 in GlcNAc metabolism.

  13. Identification of GIG1, a GlcNAc-Induced Gene in Candida albicans Needed for Normal Sensitivity to the Chitin Synthase Inhibitor Nikkomycin Z▿§

    Science.gov (United States)

    Gunasekera, Angelo; Alvarez, Francisco J.; Douglas, Lois M.; Wang, Hong X.; Rosebrock, Adam P.; Konopka, James B.

    2010-01-01

    The amino sugar N-acetylglucosamine (GlcNAc) is known to be an important structural component of cells from bacteria to humans, but its roles in cell signaling are less well understood. GlcNAc induces two pathways in the human fungal pathogen Candida albicans. One activates cyclic AMP (cAMP) signaling, which stimulates the formation of hyphal cells and the expression of virulence genes, and the other pathway induces genes needed to catabolize GlcNAc. Microarray analysis of gene expression was carried out under four different conditions in order to characterize the transcriptional changes induced by GlcNAc. The most highly induced genes include those that encode a GlcNAc transporter (NGT1) and the GlcNAc catabolic enzymes (HXK1, DAC1, and NAG1). GlcNAc also activated most of the genes whose expression is increased when cells are triggered with other stimuli to form hyphae. Surprisingly, GlcNAc also induced a subset of genes that are regulated by galactose (GAL1, GAL7, and GAL10), which may be due to cross talk between signaling pathways. A novel GlcNAc-induced gene, GIG1, which is not essential for GlcNAc catabolism or the induction of hyphae, was identified. However, a Gig1-green fluorescent protein (GFP) fusion protein was specifically induced by GlcNAc, and not by other sugars. Gig1-GFP localized to the cytoplasm, where GlcNAc metabolism occurs. Significantly, a gig1Δ mutant displayed increased resistance to nikkomycin Z, which inhibits chitin synthase from converting UDP-GlcNAc into cell wall chitin. Gig1 is highly conserved in fungi, especially those that contain GlcNAc catabolic genes. These results implicate Gig1 in GlcNAc metabolism. PMID:20675577

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Stamenov N.

    2016-03-01

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

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    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. Prospective evaluation of the chromogenic medium CandiSelect 4 for differentiation and presumptive identification of non-Candida albicans Candida species

    NARCIS (Netherlands)

    Zhao, Liang; de Hoog, G Sybren; Cornelissen, Akke; Lyu, Qian; Mou, Lili; Liu, Taohua; Cao, Yu; Vatanshenassan, Mansoureh; Kang, Yingqian

    Rapid identification of pathogenic yeasts is a crucial step in timely and appropriate antifungal therapy. For diagnostics in the clinical laboratory, simplified alternatives to barcoding are needed. CandiSelect 4 (CS4) medium, a chromogenic medium for isolation of clinical yeasts, allows routine

  19. Influência de Lactobacillus rhamnosus na patogenicidade e na expressão de genes de virulência de Candida albicans: estudo in vitro e in vivo

    OpenAIRE

    Ribeiro, Felipe de Camargo [UNESP

    2015-01-01

    The high incidence of candidiasis caused by Candida albicans and the adaptability of this species, as well as resistance to antifungal drive the development of research on alternative therapies to control this infection. The aim of this study was to evaluate the influence of Lactobacillus rhamnosus and products of their metabolism against C. albicans, evaluating the pathogenicity and the expression of genes that regulate the formation of C. albicans biofilms in vitro and in vivo in invertebra...

  20. Fungal Biofilms: In Vivo Models for Discovery of Anti-Biofilm Drugs.

    Science.gov (United States)

    Nett, Jeniel E; Andes, David R

    2015-06-01

    During infection, fungi frequently transition to a biofilm lifestyle, proliferating as communities of surface-adherent aggregates of cells. Phenotypically, cells in a biofilm are distinct from free-floating cells. Their high tolerance of antifungals and ability to withstand host defenses are two characteristics that foster resilience. Biofilm infections are particularly difficult to eradicate, and most available antifungals have minimal activity. Therefore, the discovery of novel compounds and innovative strategies to treat fungal biofilms is of great interest. Although many fungi have been observed to form biofilms, the most well-studied is Candida albicans. Animal models have been developed to simulate common Candida device-associated infections, including those involving vascular catheters, dentures, urinary catheters, and subcutaneous implants. Models have also reproduced the most common mucosal biofilm infections: oropharyngeal and vaginal candidiasis. These models incorporate the anatomical site, immune components, and fluid dynamics of clinical niches and have been instrumental in the study of drug resistance and investigation of novel therapies. This chapter describes the significance of fungal biofilm infections, the animal models developed for biofilm study, and how these models have contributed to the development of new strategies for the eradication of fungal biofilm infections.

  1. Anti-Biofilm Efficacy of Nitric Oxide-Releasing Silica Nanoparticles

    OpenAIRE

    Hetrick, Evan M.; Shin, Jae Ho; Paul, Heather S.; Schoenfisch, Mark H.

    2009-01-01

    The ability of nitric oxide (NO)-releasing silica nanoparticles to kill biofilm-based microbial cells is reported. Biofilms of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans were formed in vitro and exposed to NO-releasing silica nanoparticles. Replicative viability experiments revealed that ≥ 99% of cells from each type of biofilm were killed via NO release, with the greatest efficacy (≥ 99.999% killing) against gram-negative...

  2. Identification of Genes Involved in Biofilm Formation and Respiration via Mini-Himar Transposon Mutagenesis of Geobacter sulfurreducens▿ †

    Science.gov (United States)

    Rollefson, Janet B.; Levar, Caleb E.; Bond, Daniel R.

    2009-01-01

    Electron transfer from cells to metals and electrodes by the Fe(III)-reducing anaerobe Geobacter sulfurreducens requires proper expression of redox proteins and attachment mechanisms to interface bacteria with surfaces and neighboring cells. We hypothesized that transposon mutagenesis would complement targeted knockout studies in Geobacter spp. and identify novel genes involved in this process. Escherichia coli mating strains and plasmids were used to develop a conjugation protocol and deliver mini-Himar transposons, creating a library of over 8,000 mutants that was anaerobically arrayed and screened for a range of phenotypes, including auxotrophy for amino acids, inability to reduce Fe(III) citrate, and attachment to surfaces. Following protocol validation, mutants with strong phenotypes were further characterized in a three-electrode system to simultaneously quantify attachment, biofilm development, and respiratory parameters, revealing mutants defective in Fe(III) reduction but unaffected in electron transfer to electrodes (such as an insertion in GSU1330, a putative metal export protein) or defective in electrode reduction but demonstrating wild-type biofilm formation (due to an insertion upstream of the NHL domain protein GSU2505). An insertion in a putative ATP-dependent transporter (GSU1501) eliminated electrode colonization but not Fe(III) citrate reduction. A more complex phenotype was demonstrated by a mutant containing an insertion in a transglutaminase domain protein (GSU3361), which suddenly ceased to respire when biofilms reached approximately 50% of the wild-type levels. As most insertions were not in cytochromes but rather in transporters, two-component signaling proteins, and proteins of unknown function, this collection illustrates how biofilm formation and electron transfer are separate but complementary phenotypes, controlled by multiple loci not commonly studied in Geobacter spp. PMID:19395486

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

    Directory of Open Access Journals (Sweden)

    Ria Puspitawati

    2013-07-01

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

  4. Differentiation between Candida albicans and Candida dubliniensis using hypertonic Sabouraud broth and tobacco agar

    Directory of Open Access Journals (Sweden)

    Fabíola Silveira-Gomes

    2011-08-01

    Full Text Available INTRODUCTION: Opportunistic fungal infections in immunocompromised hosts are caused by Candida species, and the majority of such infections are due to Candida albicans. However, the emerging pathogen Candida dubliniensis demonstrates several phenotypic characteristics in common with C. albicans, such as production of germ tubes and chlamydospores, calling attention to the development of stable resistance to fluconazole in vitro. The aim of this study was to evaluate the performance of biochemistry identification in the differentiating between C. albicans and C. dubliniensis, by phenotyping of yeast identified as C. albicans. METHODS: Seventy-nine isolates identified as C. albicans by the API system ID 32C were grown on Sabouraud dextrose agar at 30°C for 24-48h and then inoculated on hypertonic Sabouraud broth and tobacco agar. RESULTS: Our results showed that 17 (21.5% isolates were growth-inhibited on hypertonic Sabouraud broth, a phenotypic trait inconsistent with C. albicans in this medium. However, the results observed on tobacco agar showed that only 9 (11.4% of the growth-inhibited isolates produced characteristic colonies of C. dubliniensis (rough colonies, yellowish-brown with abundant fragments of hyphae and chlamydospores. CONCLUSIONS: The results suggest that this method is a simple tool for screening C. albicans and non-albicans yeast and for verification of automated identification.

  5. Differentiation between Candida albicans and Candida dubliniensis using hypertonic Sabouraud broth and tobacco agar.

    Science.gov (United States)

    Silveira-Gomes, Fabíola; Sarmento, Dayse Nogueira; Espírito-Santo, Elaine Patrícia Tavares do; Souza, Nádia de Oliveira; Pinto, Thifany Mendes; Marques-da-Silva, Silvia Helena

    2011-01-01

    Opportunistic fungal infections in immunocompromised hosts are caused by Candida species, and the majority of such infections are due to Candida albicans. However, the emerging pathogen Candida dubliniensis demonstrates several phenotypic characteristics in common with C. albicans, such as production of germ tubes and chlamydospores, calling attention to the development of stable resistance to fluconazole in vitro. The aim of this study was to evaluate the performance of biochemistry identification in the differentiating between C. albicans and C. dubliniensis, by phenotyping of yeast identified as C. albicans. Seventy-nine isolates identified as C. albicans by the API system ID 32C were grown on Sabouraud dextrose agar at 30°C for 24-48h and then inoculated on hypertonic Sabouraud broth and tobacco agar. Our results showed that 17 (21.5%) isolates were growth-inhibited on hypertonic Sabouraud broth, a phenotypic trait inconsistent with C. albicans in this medium. However, the results observed on tobacco agar showed that only 9 (11.4%) of the growth-inhibited isolates produced characteristic colonies of C. dubliniensis (rough colonies, yellowish-brown with abundant fragments of hyphae and chlamydospores). The results suggest that this method is a simple tool for screening C. albicans and non-albicans yeast and for verification of automated identification.

  6. Biofilm Infections

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Jensen, Peter Østrup; Moser, Claus Ernst

    A still increasing interest and emphasis on the sessile bacterial lifestyle biofilms has been seen since it was realized that the vast majority of the total microbial biomass exists as biofilms. Aggregation of bacteria was first described by Leeuwenhoek in 1677, but only recently recognized...... as being important in chronic infection. In 1993 the American Society for Microbiology (ASM) recognized that the biofilm mode of growth was relevant to microbiology. This book covers both the evidence for biofilms in many chronic bacterial infections as well as the problems facing these infections...... such as diagnostics, pathogenesis, treatment regimes and in vitro and in vivo models for studying biofilms. This is the first scientific book on biofilm infections, chapters written by the world leading scientist and clinicians. The intended audience of this book is scientists, teachers at university level as well...

  7. 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.

  8. 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)

  9. 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.

  10. A Candida biofilm-induced pathway for matrix glucan delivery: implications for drug resistance.

    Directory of Open Access Journals (Sweden)

    Heather T Taff

    Full Text Available Extracellular polysaccharides are key constituents of the biofilm matrix of many microorganisms. One critical carbohydrate component of Candida albicans biofilms, β-1,3 glucan, has been linked to biofilm protection from antifungal agents. In this study, we identify three glucan modification enzymes that function to deliver glucan from the cell to the extracellular matrix. These enzymes include two predicted glucan transferases and an exo-glucanase, encoded by BGL2, PHR1, and XOG1, respectively. We show that the enzymes are crucial for both delivery of β-1,3 glucan to the biofilm matrix and for accumulation of mature matrix biomass. The enzymes do not appear to impact cell wall glucan content of biofilm cells, nor are they necessary for filamentation or biofilm formation. We demonstrate that mutants lacking these genes exhibit enhanced susceptibility to the commonly used antifungal, fluconazole, during biofilm growth only. Transcriptional analysis and biofilm phenotypes of strains with multiple mutations suggest that these enzymes act in a complementary fashion to distribute matrix downstream of the primary β-1,3 glucan synthase encoded by FKS1. Furthermore, our observations suggest that this matrix delivery pathway works independently from the C. albicans ZAP1 matrix formation regulatory pathway. These glucan modification enzymes appear to play a biofilm-specific role in mediating the delivery and organization of mature biofilm matrix. We propose that the discovery of inhibitors for these enzymes would provide promising anti-biofilm therapeutics.

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

    Directory of Open Access Journals (Sweden)

    Lakshmi A. Leepel

    2012-10-01

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

  12. 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.

  13. Biofilm Development

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim

    2015-01-01

    During the past decade we have gained much knowledge about the molecular mechanisms that are involved in initiation and termination of biofilm formation. In many bacteria, these processes appear to occur in response to specific environmental cues and result in, respectively, induction or terminat......During the past decade we have gained much knowledge about the molecular mechanisms that are involved in initiation and termination of biofilm formation. In many bacteria, these processes appear to occur in response to specific environmental cues and result in, respectively, induction...... or termination of biofilm matrix production via the second messenger molecule c-di-GMP. In between initiation and termination of biofilm formation we have defined specific biofilm stages, but the currently available evidence suggests that these transitions are mainly governed by adaptive responses......, and not by specific genetic programs. It appears that biofilm formation can occur through multiple pathways and that the spatial structure of the biofilms is species dependent as well as dependent on environmental conditions. Bacterial subpopulations, e.g., motile and nonmotile subpopulations, can develop...

  14. Spectroscopic identification and anti-biofilm properties of polar metabolites from the medicinal plant Helichrysum italicum against Pseudomonas aeruginosa.

    Science.gov (United States)

    D'Abrosca, Brigida; Buommino, Elisabetta; D'Angelo, Grazia; Coretti, Lorena; Scognamiglio, Monica; Severino, Valeria; Pacifico, Severina; Donnarumma, Giovanna; Fiorentino, Antonio

    2013-11-15

    Two new acylated styrylpyrones, one 5-methoxy-1(3H)-isobenzofuranone glucoside and a hydroxymethyl-orcinol derivative, along with sixteen known aromatic metabolites, including lignans, quinic acid derivatives low-molecular weight phenol glucosides, have been isolated from the methanol extract of Helichrysum italicum, a medicinal plant typical of the Mediterranean vegetation. The structures of these compounds have been elucidated on the basis of extensive 2D-NMR spectroscopic analyses, including COSY, TOCSY, HSQC, CIGAR-HMBC, H2BC and HSQC-TOCSY, along with Q-TOF HRMS(2) analysis. Selected compounds were evaluated for their anti-biofilm properties against Pseudomonas aeruginosa. Copyright © 2013. Published by Elsevier Ltd.

  15. Identification and characterization of an operon, msaABCR, that controls virulence and biofilm development in Staphylococcus aureus.

    Science.gov (United States)

    Sahukhal, Gyan S; Elasri, Mohamed O

    2014-06-11

    Community-acquired, methicillin-resistant Staphylococcus aureus strains often cause localized infections in immunocompromised hosts, but some strains show enhanced virulence leading to severe infections even among healthy individuals with no predisposing risk factors. The genetic basis for this enhanced virulence has yet to be determined. S. aureus possesses a wide variety of virulence factors, the expression of which is carefully coordinated by a variety of regulators. Several virulence regulators have been well characterized, but others have yet to be thoroughly investigated. Previously, we identified the msa gene as a regulator of several virulence genes, biofilm development, and antibiotic resistance. We also found evidence of the involvement of upstream genes in msa function. To investigate the mechanism of regulation of the msa gene (renamed msaC), we examined the upstream genes whose expression was affected by its deletion. We showed that msaC is part of a newly defined four-gene operon (msaABCR), in which msaC is a non-protein-coding RNA that is essential for the function of the operon. Furthermore, we found that an antisense RNA (msaR) is complementary to the 5' end of the msaB gene and is expressed in a growth phase-dependent manner suggesting that it is involved in regulation of the operon. These findings allow us to define a new operon that regulates fundamental phenotypes in S. aureus such as biofilm development and virulence. Characterization of the msaABCR operon will allow us to investigate the mechanism of function of this operon and the role of the individual genes in regulation and interaction with its targets. This study identifies a new element in the complex regulatory circuits in S. aureus, and our findings may be therapeutically relevant.

  16. 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

  17. Candida Biofilms: Threats, Challenges, and Promising Strategies

    Directory of Open Access Journals (Sweden)

    Mafalda Cavalheiro

    2018-02-01

    Full Text Available Candida species are fungal pathogens known for their ability to cause superficial and systemic infections in the human host. These pathogens are able to persist inside the host due to the development of pathogenicity and multidrug resistance traits, often leading to the failure of therapeutic strategies. One specific feature of Candida species pathogenicity is their ability to form biofilms, which protects them from external factors such as host immune system defenses and antifungal drugs. This review focuses on the current threats and challenges when dealing with biofilms formed by Candida albicans, Candida glabrata, Candida tropicalis, and Candida parapsilosis, highlighting the differences between the four species. Biofilm characteristics depend on the ability of each species to produce extracellular polymeric substances (EPS and display dimorphic growth, but also on the biofilm substratum, carbon source availability and other factors. Additionally, the transcriptional control over processes like adhesion, biofilm formation, filamentation, and EPS production displays great complexity and diversity within pathogenic yeasts of the Candida genus. These differences not only have implications in the persistence of colonization and infections but also on antifungal resistance typically found in Candida biofilm cells, potentiated by EPS, that functions as a barrier to drug diffusion, and by the overexpression of drug resistance transporters. The ability to interact with different species in in vivo Candida biofilms is also a key factor to consider when dealing with this problem. Despite many challenges, the most promising strategies that are currently available or under development to limit biofilm formation or to eradicate mature biofilms are discussed.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. 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.

  20. Bacterial biofilms and antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Liliana Caldas-Arias

    2015-04-01

    Full Text Available Biofilms give to bacteria micro-environmental benefits; confers protection against antimicrobials. Bacteria have antibiotic resistance by conventional and unusual mechanisms leading to delayed wound healing, to increase recurrent chronic infections and nosocomial contamination of medical devices. Objective: This narrative review aims to introduce the characteristics of Bacteria-biofilms, antimicrobial resistance mechanisms and potential alternatives for prevention and control of its formation. Methods: Search strategy was performed on records: PubMed / Medline, Lilacs, Redalyc; with suppliers such as EBSCO and thesaurus MeSH and DeCS. Conclusions: Knowledge and research performance of biofilm bacteria are relevant in the search of technology for detection and measuring sensitivity to antibiotics. The identification of Bacterial-biofilms needs no-traditional microbiological diagnosis.

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

    Science.gov (United States)

    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

  2. Wound biofilms: lessons learned from oral biofilms

    OpenAIRE

    Mancl, Kimberly A.; Kirsner, Robert S.; Ajdic, Dragana

    2013-01-01

    Biofilms play an important role in the development and pathogenesis of many chronic infections. Oral biofilms, more commonly known as dental plaque,are a primary cause of oral diseases including caries, gingivitis and periodontitis. Oral biofilms are commonly studied as model biofilm systems as they are easily accessible, thus biofilm research in oral diseases is advanced with details of biofilm formation and bacterial interactions being well-elucidated. In contrast, wound research has relati...

  3. Identification of Xylella fastidiosa antivirulence genes: hemagglutinin adhesins contribute a biofilm maturation to X. fastidios and colonization and attenuate virulence.

    Science.gov (United States)

    Guilhabert, Magalie R; Kirkpatrick, Bruce C

    2005-08-01

    Xylella fastidosa, a gram-negative, xylem-limited bacterium, is the causal agent of several economically important plant diseases, including Pierce's disease (PD) and citrus variegated chlorosis (CVC). Until recently, the inability to transform or produce transposon mutants of X. fastidosa had been a major impediment to identifying X. fastidosa genes that mediate pathogen and plant interactions. A random transposon (Tn5) library of X. fastidosa was constructed and screened for mutants showing more severe symptoms and earlier grapevine death (hypervirulence) than did vines infected with the wild type. Seven hypervirulent mutants identified in this screen moved faster and reached higher populations than the wild type in grapevines. These results suggest that X. fastidosa attenuates its virulence in planta and that movement is important in X. fastidosa virulence. The mutated genes were sequenced and none had been described previously as antivirulence genes, although six of them showed similarity with genes of known functions in other organisms. One transposon insertion inactivated a hemagglutinin adhesin gene (PD2118), which we named HxfA. Another mutant in a second putative X. fastidosa hemagglutinin gene, PD1792 (HxfB), was constructed, and further characterization of these hxf mutants suggests that X. fastidosa hemagglutinins mediate contact between X. fastidosa cells, which results in colony formation and biofilm maturation within the xylem vessels.

  4. Identification of Molecular and Cellular Responses of Desulfovibrio vulgaris Biofilms under Culture Conditions Relevant to Field Conditions for Bioreduction of Toxic Metals and Radionuclides. Final report

    International Nuclear Information System (INIS)

    Wall, Judy D.

    2011-01-01

    Our findings demonstrated that D. vulgaris surface-adhered populations produce extracellular structures, and that the cells have altered carbon and energy flux compared to planktonic cells. Biofilms did not have greatly increased carbohydrate accumulation. Interestingly genes present on the native plasmid found in D. vulgaris Hildenborough were necessary for wild type biofilm formation. In addition, extracellular appendages dependent on functions or proteins encoded by flaG or fliA also contributed to biofilm formation. Studies with SRB biofilms have indicated that the reduction and precipitation of metals can occur within the biofilm matrix; however, little work has been done to elucidate the physiological state of surface-adhered cells during metal reduction (Cr6+, U6+) and how this process is affected by nutrient feed levels (i.e., the stimulant).

  5. Identification of Molecular and Cellular Responses of Desulfovibrio vulgaris Biofilms under Culture Conditions Relevant to Field Conditions for Bioreduction of Toxic Metals and Radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Judy D. Wall

    2011-06-09

    Our findings demonstrated that D. vulgaris surface-adhered populations produce extracellular structures, and that that the cells have altered carbon and energy flux compared to planktonic cells. Biofilms did not have greatly increased carbohydrate accumulation. Interestingly genes present on the native plasmid found in D. vulgaris Hildenborough were necessary for wild type biofilm formation. In addition, extracellular appendages dependent on functions or proteins encoded by flaG or fliA also contributed to biofilm formation. Studies with SRB biofilms have indicated that the reduction and precipitation of metals can occur within the biofilm matrix; however, little work has been done to elucidate the physiological state of surface-adhered cells during metal reduction (Cr6+, U6+) and how this process is affected by nutrient feed levels (i.e., the stimulant).

  6. Antifungal Activity of 14-Helical β-Peptides against Planktonic Cells and Biofilms of Candida Species

    Directory of Open Access Journals (Sweden)

    Namrata Raman

    2015-08-01

    Full Text Available Candida albicans is the most prevalent cause of fungal infections and treatment is further complicated by the formation of drug resistant biofilms, often on the surfaces of implanted medical devices. In recent years, the incidence of fungal infections by other pathogenic Candida species such as C. glabrata, C. parapsilosis and C. tropicalis has increased. Amphiphilic, helical β-peptide structural mimetics of natural antimicrobial α-peptides have been shown to exhibit specific planktonic antifungal and anti-biofilm formation activity against C. albicans in vitro. Here, we demonstrate that β-peptides are also active against clinically isolated and drug resistant strains of C. albicans and against other opportunistic Candida spp. Different Candida species were susceptible to β-peptides to varying degrees, with C. tropicalis being the most and C. glabrata being the least susceptible. β-peptide hydrophobicity directly correlated with antifungal activity against all the Candida clinical strains and species tested. While β-peptides were largely ineffective at disrupting existing Candida biofilms, hydrophobic β-peptides were able to prevent the formation of C. albicans, C. glabrata, C. parapsilosis and C. tropicalis biofilms. The broad-spectrum antifungal activity of β-peptides against planktonic cells and in preventing biofilm formation suggests the promise of this class of molecules as therapeutics.

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

    Directory of Open Access Journals (Sweden)

    S R Fule

    2015-01-01

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

  8. Effects of lactoferricin B against keratitis-associated fungal biofilms.

    Science.gov (United States)

    Sengupta, Jayangshu; Saha, Suman; Khetan, Archana; Sarkar, Sujoy K; Mandal, Santi M

    2012-10-01

    Biofilms are considered as the most important developmental characteristics in ocular infections. Biofilm eradication is a major challenge today to overcome the incidence of drug resistance. This report demonstrates the in vitro ability of biofilm formation on contact lens by three common keratitis-associated fungal pathogens, namely, Aspergillus fumigatus, Fusarium solani, and Candida albicans. Antifungal sensitivity testing performed for both planktonic cells and biofilm revealed the sessile phenotype to be resistant at MIC levels for the planktonic cells and also at higher concentrations. A prototype lens care solution was also found to be partially effective in eradication of the mature biofilm from contact lenses. Lactoferricin B (Lacf, 64 μg/ml), an antimicrobial peptide, exhibited almost no effect on the sessile phenotype. However, the combinatory effect of Lacf with antifungals against planktonic cells and biofilms of three fungal strains that were isolated from keratitis patients exhibited a reduction of antifungal dose more than eightfold. Furthermore, the effect of Lacf in lens care solution against biofilms in which those strains formed was eradicated successfully. These results suggest that lactoferricin B could be a promising candidate for clinical use in improving biofilm susceptibility to antifungals and also as an antibiofilm-antifungal additive in lens care solution.

  9. Candida glabrata Biofilms: How Far Have We Come?

    Science.gov (United States)

    Rodrigues, Célia F.; Rodrigues, Maria Elisa; Silva, Sónia; Henriques, Mariana

    2017-01-01

    Infections caused by Candida species have been increasing in the last decades and can result in local or systemic infections, with high morbidity and mortality. After Candida albicans, Candida glabrata is one of the most prevalent pathogenic fungi in humans. In addition to the high antifungal drugs resistance and inability to form hyphae or secret hydrolases, C. glabrata retain many virulence factors that contribute to its extreme aggressiveness and result in a low therapeutic response and serious recurrent candidiasis, particularly biofilm formation ability. For their extraordinary organization, especially regarding the complex structure of the matrix, biofilms are very resistant to antifungal treatments. Thus, new approaches to the treatment of C. glabrata’s biofilms are emerging. In this article, the knowledge available on C. glabrata’s resistance will be highlighted, with a special focus on biofilms, as well as new therapeutic alternatives to control them. PMID:29371530

  10. Candida glabrata Biofilms: How Far Have We Come?

    Directory of Open Access Journals (Sweden)

    Célia F. Rodrigues

    2017-03-01

    Full Text Available Infections caused by Candida species have been increasing in the last decades and can result in local or systemic infections, with high morbidity and mortality. After Candida albicans, Candida glabrata is one of the most prevalent pathogenic fungi in humans. In addition to the high antifungal drugs resistance and inability to form hyphae or secret hydrolases, C. glabrata retain many virulence factors that contribute to its extreme aggressiveness and result in a low therapeutic response and serious recurrent candidiasis, particularly biofilm formation ability. For their extraordinary organization, especially regarding the complex structure of the matrix, biofilms are very resistant to antifungal treatments. Thus, new approaches to the treatment of C. glabrata’s biofilms are emerging. In this article, the knowledge available on C. glabrata’s resistance will be highlighted, with a special focus on biofilms, as well as new therapeutic alternatives to control them.

  11. 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

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

    Science.gov (United States)

    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.

  13. Biofilm antifungal susceptibility of Candida urine isolated from ambulatory patients

    Directory of Open Access Journals (Sweden)

    Débora da Luz Becker

    2016-07-01

    Full Text Available Background and Objectives: the association between the biofilm formations an antifungal resistance has been suggested to be an important factor in the pathogenesis of several Candida species. Besides, studies have included invasive candidiasis from hospitalized patients; however there are few studies that evaluated the species distribution, antifungal susceptibility and biofilm formation of Candida species isolated from ambulatory patients. Thus, the aim of this study was to evaluate whether biofilm producing contributes to antifungal resistance in Candida isolates from urine sample obtained from ambulatory patients. Methods: During one year, 25 urine samples positive for yeast were collected, stored and plated on agar supplemented with chloramphenicol and Sabouread left at room temperature for 5 days for subsequent: 52% (13/25 were C. albicans, 36% (9/25 C. tropicalis, 8% (2/25 C. krusei and 4% (1/25 C. parapsilosis. Results: The ability to form biofilm was detected in 23 (92% of the yeast studied and 15.4% (2/13 of C. albicans were fluconazole (FLU and ketoconazole (KET resistant, while 11.1% (1/9 of C. tropicalis were ketoconazole resistant and were anidulafungin (ANI non-susceptible. Conclusion: our results showed the high capacity for biofilm formation among Candida isolates from ambulatory patients.

  14. Species-Specific and Drug-Specific Differences in Susceptibility of Candida Biofilms to Echinocandins: Characterization of Less Common Bloodstream Isolates

    Science.gov (United States)

    Simitsopoulou, Maria; Peshkova, Pavla; Tasina, Efthymia; Katragkou, Aspasia; Kyrpitzi, Daniela; Velegraki, Aristea; Walsh, Thomas J.

    2013-01-01

    Candida species other than Candida albicans are increasingly recognized as causes of biofilm-associated infections. This is a comprehensive study that compared the in vitro activities of all three echinocandins against biofilms formed by different common and infrequently identified Candida isolates. We determined the activities of anidulafungin (ANID), caspofungin (CAS), and micafungin (MFG) against planktonic cells and biofilms of bloodstream isolates of C. albicans (15 strains), Candida parapsilosis (6 strains), Candida lusitaniae (16 strains), Candida guilliermondii (5 strains), and Candida krusei (12 strains) by XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] assay. Planktonic and biofilm MICs were defined as ≥50% fungal damage. Planktonic cells of all Candida species were susceptible to the three echinocandins, with MICs of ≤1 mg/liter. By comparison, differences in the MIC profiles of biofilms in response to echinocandins existed among the Candida species. Thus, C. lusitaniae and C. guilliermondii biofilms were highly recalcitrant to all echinocandins, with MICs of ≥32 mg/liter. In contrast, the MICs of all three echinocandins for C. albicans and C. krusei biofilms were relatively low (MICs ≤ 1 mg/liter). While echinocandins exhibited generally high MICs against C. parapsilosis biofilms, MFG exhibited the lowest MICs against these isolates (4 mg/liter). A paradoxical growth effect was observed with CAS concentrations ranging from 8 to 64 mg/liter against C. albicans and C. parapsilosis biofilms but not against C. krusei, C. lusitaniae, or C. guilliermondii. While non-albicans Candida planktonic cells were susceptible to all echinocandins, there were drug- and species-specific differences in susceptibility among biofilms of the various Candida species, with C. lusitaniae and C. guilliermondii exhibiting profiles of high MICs of the three echinocandins. PMID:23529739

  15. Enterococcus faecium biofilm formation: identification of major autolysin AtlAEfm, associated Acm surface localization, and AtlAEfm-independent extracellular DNA Release.

    Science.gov (United States)

    Paganelli, Fernanda L; Willems, Rob J L; Jansen, Pamela; Hendrickx, Antoni; Zhang, Xinglin; Bonten, Marc J M; Leavis, Helen L

    2013-04-16

    Enterococcus faecium is an important multidrug-resistant nosocomial pathogen causing biofilm-mediated infections in patients with medical devices. Insight into E. faecium biofilm pathogenesis is pivotal for the development of new strategies to prevent and treat these infections. In several bacteria, a major autolysin is essential for extracellular DNA (eDNA) release in the biofilm matrix, contributing to biofilm attachment and stability. In this study, we identified and functionally characterized the major autolysin of E. faecium E1162 by a bioinformatic genome screen followed by insertional gene disruption of six putative autolysin genes. Insertional inactivation of locus tag EfmE1162_2692 resulted in resistance to lysis, reduced eDNA release, deficient cell attachment, decreased biofilm, decreased cell wall hydrolysis, and significant chaining compared to that of the wild type. Therefore, locus tag EfmE1162_2692 was considered the major autolysin in E. faecium and renamed atlAEfm. In addition, AtlAEfm was implicated in cell surface exposure of Acm, a virulence factor in E. faecium, and thereby facilitates binding to collagen types I and IV. This is a novel feature of enterococcal autolysins not described previously. Furthermore, we identified (and localized) autolysin-independent DNA release in E. faecium that contributes to cell-cell interactions in the atlAEfm mutant and is important for cell separation. In conclusion, AtlAEfm is the major autolysin in E. faecium and contributes to biofilm stability and Acm localization, making AtlAEfm a promising target for treatment of E. faecium biofilm-mediated infections. IMPORTANCE Nosocomial infections caused by Enterococcus faecium have rapidly increased, and treatment options have become more limited. This is due not only to increasing resistance to antibiotics but also to biofilm-associated infections. DNA is released in biofilm matrix via cell lysis, caused by autolysin, and acts as a matrix stabilizer. In this study

  16. Development of a calibration protocol and identification of the most sensitive parameters for the particulate biofilm models used in biological wastewater treatment.

    Science.gov (United States)

    Eldyasti, Ahmed; Nakhla, George; Zhu, Jesse

    2012-05-01

    Biofilm models are valuable tools for process engineers to simulate biological wastewater treatment. In order to enhance the use of biofilm models implemented in contemporary simulation software, model calibration is both necessary and helpful. The aim of this work was to develop a calibration protocol of the particulate biofilm model with a help of the sensitivity analysis of the most important parameters in the biofilm model implemented in BioWin® and verify the predictability of the calibration protocol. A case study of a circulating fluidized bed bioreactor (CFBBR) system used for biological nutrient removal (BNR) with a fluidized bed respirometric study of the biofilm stoichiometry and kinetics was used to verify and validate the proposed calibration protocol. Applying the five stages of the biofilm calibration procedures enhanced the applicability of BioWin®, which was capable of predicting most of the performance parameters with an average percentage error (APE) of 0-20%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Hydraulic resistance of biofilms

    KAUST Repository

    Dreszer, C.; Vrouwenvelder, Johannes S.; Paulitsch-Fuchs, Astrid H.; Zwijnenburg, Arie; Kruithof, Joop C.; Flemming, Hans Curt

    2013-01-01

    resistance is very low compared to the expected biofilm resistance and, thus, biofilm resistance can be determined accurately. Transmembrane pressure drop was monitored. As biofilm parameters, thickness, total cell number, TOC, and extracellular polymeric

  18. 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.

  19. Effects of undecylenic acid released from denture liner on Candida biofilms.

    Science.gov (United States)

    Gonçalves, L M; Del Bel Cury, A A; Sartoratto, A; Garcia Rehder, V L; Silva, W J

    2012-10-01

    Denture liners (DL) are easily colonized by Candida spp. In an attempt to prevent biofilm colonization, manufacturers have incorporated undecylenic acid (UDA) into DL. In this in vitro study, the effects of UDA released from DL on Candida biofilms were investigated. The concentrations of UDA released from commercial DL were determined by gas chromatography-mass spectrometry (GC-MS). Minimum inhibitory concentration (MIC) and minimum fungistatic concentration (MFC) tests were performed for C. albicans or C. glabrata, with UDA for comparison with the concentrations released from DL. Specimens of DL with (experimental group) and without UDA (control group) were fabricated, and Candida biofilms were developed on DL surfaces. Biofilms were evaluated by cell counts, metabolic activity, structure, and secretion of proteinase or phospholipase. The concentrations of UDA released were within the MIC and MFC ranges. In the presence of UDA, C. albicans biofilms were thinner and had lower numbers of viable and active cells, although no significant enzymatic changes were observed relative to the control group (p > 0.05). In contrast, C. glabrata biofilms exhibited higher cell counts and greater metabolic activity and also increased proteinase activity in the presence of UDA relative to the control group (p < 0.05). Overall, UDA did not prevent Candida biofilm formation.

  20. Promotion of chlamydoconidium formation in Candida albicans by corn meal broth incubation.

    Science.gov (United States)

    Nakamoto, S

    1998-04-01

    Chlamydoconidium formation can be used as a tool for the identification of Candida albicans. While chlamydoconidia are known to be inducible on corn meal agar, this report demonstrates that testing in liquid media supplemented with milk or serum enhances chlamydoconidium formation and the formation of complex mycelial clusters.

  1. The in vivo biofilm

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Alhede, Maria; Alhede, Morten

    2013-01-01

    Bacteria can grow and proliferate either as single, independent cells or organized in aggregates commonly referred to as biofilms. When bacteria succeed in forming a biofilm within the human host, the infection often becomes very resistant to treatment and can develop into a chronic state. Biofilms...... have been studied for decades using various in vitro models, but it remains debatable whether such in vitro biofilms actually resemble in vivo biofilms in chronic infections. In vivo biofilms share several structural characteristics that differ from most in vitro biofilms. Additionally, the in vivo...... experimental time span and presence of host defenses differ from chronic infections and the chemical microenvironment of both in vivo and in vitro biofilms is seldom taken into account. In this review, we discuss why the current in vitro models of biofilms might be limited for describing infectious biofilms...

  2. Identification of the amino acids essential for LytSR-mediated signal transduction in Staphylococcus aureus and their roles in biofilm-specific gene expression

    Science.gov (United States)

    Lehman, McKenzie K.; Bose, Jeffrey L.; Sharma-Kuinkel, Batu K.; Moormeier, Derek E.; Endres, Jennifer L.; Sadykov, Marat R.; Biswas, Indranil; Bayles, Kenneth W.

    2015-01-01

    Summary Recent studies have demonstrated that expression of the Staphylococcus aureus lrgAB operon is specifically expressed within tower structures during biofilm development. To gain a better understanding of the mechanisms underlying this spatial control of lrgAB expression, we carried out a detailed analysis of the LytSR two-component system. Specifically, a conserved aspartic acid (Asp53) of the LytR response regulator was shown to be the target of phosphorylation, which resulted in enhanced binding to the lrgAB promoter and activation of transcription. In addition, we identified His390 of the LytS histidine kinase as the site of autophosphorylation and Asn394 as a critical amino acid involved in phosphatase activity. Interestingly, LytS-independent activation of LytR was observed during planktonic growth, with acetyl phosphate acting as a phosphodonor to LytR. In contrast, mutations disrupting the function of LytS prevented tower-specific lrgAB expression, providing insight into the physiologic environment within these structures. In addition, over activation of LytR led to increased lrgAB promoter activity during planktonic and biofilm growth and a change in biofilm morphology. Overall, the results of this study are the first to define the LytSR signal transduction pathway, as well as determine the metabolic context within biofilm tower structures that triggers these signaling events. PMID:25491472

  3.   In situ identification of streptococci and other bacteria in initial dental biofilm by confocal laser scanning microscopy and fluorescence in situ hybridization

    DEFF Research Database (Denmark)

    Dige, Irene; Kilian, Mogens; Nilsson, Holger

    2007-01-01

    Confocal laser scanning microscopy (CLSM) has been employed as a method for studying intact natural biofilm. When combined with fluorescence in situ hybridization (FISH) it is possible to analyze spatial relationships and changes of specific members of microbial populations over time. The aim...

  4. Biophysics of biofilm infection.

    Science.gov (United States)

    Stewart, Philip S

    2014-04-01

    This article examines a likely basis of the tenacity of biofilm infections that has received relatively little attention: the resistance of biofilms to mechanical clearance. One way that a biofilm infection persists is by withstanding the flow of fluid or other mechanical forces that work to wash or sweep microorganisms out of the body. The fundamental criterion for mechanical persistence is that the biofilm failure strength exceeds the external applied stress. Mechanical failure of the biofilm and release of planktonic microbial cells is also important in vivo because it can result in dissemination of infection. The fundamental criterion for detachment and dissemination is that the applied stress exceeds the biofilm failure strength. The apparent contradiction for a biofilm to both persist and disseminate is resolved by recognizing that biofilm material properties are inherently heterogeneous. There are also mechanical aspects to the ways that infectious biofilms evade leukocyte phagocytosis. The possibility of alternative therapies for treating biofilm infections that work by reducing biofilm cohesion could (1) allow prevailing hydrodynamic shear to remove biofilm, (2) increase the efficacy of designed interventions for removing biofilms, (3) enable phagocytic engulfment of softened biofilm aggregates, and (4) improve phagocyte mobility and access to biofilm. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  5. The in vitro and in vivo efficacy of fluconazole in combination with farnesol against Candida albicans isolates using a murine vulvovaginitis model.

    Science.gov (United States)

    Bozó, Aliz; Domán, Marianna; Majoros, László; Kardos, Gábor; Varga, István; Kovács, Renátó

    2016-11-01

    Farnesol is a quorum-sensing molecule that inhibits biofilm formation in Candida albicans. Previous in vitro data suggest that, in combination with certain antifungals, farnesol may have an adjuvant anti-biofilm agent. However, the in vivo efficacy of farnesol is very questionable. Therefore, the in vitro and in vivo activity of fluconazole combined with farnesol was evaluated against C. albicans biofilms using fractional inhibitory concentration index (FICI) determination, time-kill experiments and a murine vulvovaginitis model. The median biofilm MICs of fluconazole-sensitive C. albicans isolates ranged between 4 -> 512 mg/L and 150-300 μM for fluconazole and farnesol, respectively. These values were 512 -> 512 mg/L and > 300 μM for fluconazole-resistant clinical isolates. Farnesol decreased the median MICs of fluconazole by 2-64-fold for biofilms. Based on FICI, synergistic interaction was observed only in the case of the sessile SC5314 reference strain (FICIs: 0.16-0.27). In time-kill studies, only the 512 mg/L fluconazole and 512 mg/L fluconazole + 75 μM farnesol reduced biofilm mass significantly at each time point in the case of all isolates. The combination reduced the metabolic activity of biofilms for all isolates in a concentration- and time-dependent manner. Our findings revealed that farnesol alone was not protective in a murine vulvovaginitis model. Farnesol was not beneficial in combination with fluconazole for fluconazole-susceptible isolates, but partially increased fluconazole activity against one fluconazole-resistant isolate, but not the other one.

  6. Biofilm-specific extracellular matrix proteins of non-typeable Haemophilus influenzae

    Science.gov (United States)

    Wu, Siva; Baum, Marc M.; Kerwin, James; Guerrero-Given, Debbie; Webster, Simon; Schaudinn, Christoph; VanderVelde, David; Webster, Paul

    2014-01-01

    Non-typeable Haemophilus influenzae (NTHi), a human respiratory tract pathogen can form colony biofilms in vitro. Bacterial cells and the amorphous extracellular matrix (ECM) constituting the biofilm can be separated using sonication. The ECM from 24 hr and 96 hr NTHi biofilms contained polysaccharides and proteinaceous components as detected by NMR and FTIR spectroscopy. More conventional chemical assays on the biofilm ECM confirmed the presence of these components and also DNA. Proteomics revealed eighteen proteins present in biofilm ECM that were not detected in planktonic bacteria. One ECM protein was unique to 24 hr biofilms, two were found only in 96 hr biofilms, and fifteen were present in the ECM of both 24 hr and 96 hr NTHi biofilms. All proteins identified were either associated with bacterial membranes or were cytoplasmic proteins. Immunocytochemistry showed two of the identified proteins, a DNA-directed RNA polymerase and the outer membrane protein OMP P2, associated with bacteria and biofilm ECM. Identification of biofilm-specific proteins present in immature biofilms is an important step in understanding the in vitro process of NTHi biofilm formation. The presence of a cytoplasmic protein and a membrane protein in the biofilm ECM of immature NTHi biofilms suggests that bacterial cell lysis may be a feature of early biofilm formation. PMID:24942343

  7. Detection of Pathogenic Biofilms with Bacterial Amyloid Targeting Fluorescent Probe, CDy11

    DEFF Research Database (Denmark)

    Kim, Jun Young; Sahu, Srikanta; Yau, Yin Hoe

    2016-01-01

    Bacterial biofilms are responsible for a wide range of persistent infections. In the clinic, diagnosis of biofilm-associated infections relies heavily on culturing methods, which fail to detect nonculturable bacteria. Identification of novel fluorescent probes for biofilm imaging will greatly...... facilitate diagnosis of pathogenic bacterial infection. Herein, we report a novel fluorescent probe, CDy11 (compound of designation yellow 11), which targets amyloid in the Pseudomonas aeruginosa biofilm matrix through a diversity oriented fluorescent library approach (DOFLA). CDy11 was further demonstrated...

  8. Biofilm Fixed Film Systems

    Directory of Open Access Journals (Sweden)

    Dipesh Das

    2011-09-01

    Full Text Available The work reviewed here was published between 2008 and 2010 and describes research that involved aerobic and anoxic biofilm treatment of water pollutants. Biofilm denitrification systems are covered when appropriate. References catalogued here are divided on the basis of fundamental research area or reactor types. Fundamental research into biofilms is presented in two sections, Biofilm Measurement and Characterization and Growth and Modeling. The reactor types covered are: trickling filters, rotating biological contactors, fluidized bed bioreactors, submerged bed biofilm reactors, biological granular activated carbon, membrane bioreactors, and immobilized cell reactors. Innovative reactors, not easily classified, are then presented, followed by a section on biofilms on sand, soil and sediment.

  9. 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.

  10. Adhesion, biofilm formation, cell surface hydrophobicity and antifungal planktonic susceptibility: relationship among Candida spp.

    Directory of Open Access Journals (Sweden)

    Ana Isabel Silva-Dias

    2015-03-01

    Full Text Available We have performed the characterization of the adhesion profile, biofilm formation, cell surface hydrophobicity (CSH and antifungal susceptibility of 184 Candida clinical isolates obtained from different human reservoirs. Adhesion was quantified using a flow cytometric assay and biofilm formation was evaluated using two methodologies: XTT and crystal violet assay. CSH was quantified with the microbial adhesion to hydrocarbons test while planktonic susceptibility was assessed accordingly the CLSI protocol for yeast M27-A3 S4.Yeast cells of non-albicans species exhibit increased ability to adhere and form biofilm. However the correlation between adhesion and biofilm formation varied according to species and also with the methodology used for biofilm assessment. No association was found between strain´s site of isolation or planktonic antifungal susceptibility and adhesion or biofilm formation. Finally CSH seemed to be a good predictor for biofilm formation but not for adhesion.Despite the marked variability registered intra and inter species, C. tropicalis and C. parapsilosis were the species exhibiting high adhesion profile. C. tropicalis, C. guilliermondii and C. krusei revealed higher biofilm formation values in terms of biomass. C. parapsilosis was the species with lower biofilm metabolic activity.

  11. Adhesion, biofilm formation, cell surface hydrophobicity, and antifungal planktonic susceptibility: relationship among Candida spp.

    Science.gov (United States)

    Silva-Dias, Ana; Miranda, Isabel M; Branco, Joana; Monteiro-Soares, Matilde; Pina-Vaz, Cidália; Rodrigues, Acácio G

    2015-01-01

    We have performed the characterization of the adhesion profile, biofilm formation, cell surface hydrophobicity (CSH) and antifungal susceptibility of 184 Candida clinical isolates obtained from different human reservoirs. Adhesion was quantified using a flow cytometric assay and biofilm formation was evaluated using two methodologies: XTT and crystal violet assay. CSH was quantified with the microbial adhesion to hydrocarbons test while planktonic susceptibility was assessed accordingly the CLSI protocol for yeast M27-A3 S4. Yeast cells of non-albicans species exhibit increased ability to adhere and form biofilm. However, the correlation between adhesion and biofilm formation varied according to species and also with the methodology used for biofilm assessment. No association was found between strain's site of isolation or planktonic antifungal susceptibility and adhesion or biofilm formation. Finally CSH seemed to be a good predictor for biofilm formation but not for adhesion. Despite the marked variability registered intra and inter species, C. tropicalis and C. parapsilosis were the species exhibiting high adhesion profile. C. tropicalis, C. guilliermondii, and C. krusei revealed higher biofilm formation values in terms of biomass. C. parapsilosis was the species with lower biofilm metabolic activity.

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

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    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.

  13. 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.

  14. Pseudomonas aeruginosa Biofilm Infections

    DEFF Research Database (Denmark)

    Rybtke, Morten; Hultqvist, Louise Dahl; Givskov, Michael

    2015-01-01

    Studies of biopsies from infectious sites, explanted tissue and medical devises have provided evidence that biofilms are the underlying cause of a variety of tissue-associated and implant-associated recalcitrant human infections. With a need for novel anti-biofilm treatment strategies, research...... in biofilm infection microbiology, biofilm formation mechanisms and biofilm-associated antimicrobial tolerance has become an important area in microbiology. Substantial knowledge about biofilm formation mechanisms, biofilm-associated antimicrobial tolerance and immune evasion mechanisms has been obtained...... through work with biofilms grown in in vitro experimental setups, and the relevance of this information in the context of chronic infections is being investigated by the use of animal models of infection. Because our current in vitro experimental setups and animal models have limitations, new advanced...

  15. A Nonbactericidal Zinc-Complexing Ligand as a Biofilm Inhibitor: Structure-Guided Contrasting Effects on Staphylococcus aureus Biofilm.

    Science.gov (United States)

    Kapoor, Vidushi; Rai, Rajanikant; Thiyagarajan, Durairaj; Mukherjee, Sandipan; Das, Gopal; Ramesh, Aiyagari

    2017-08-04

    Zinc-complexing ligands are prospective anti-biofilm agents because of the pivotal role of zinc in the formation of Staphylococcus aureus biofilm. Accordingly, the potential of a thiosemicarbazone (compound C1) and a benzothiazole-based ligand (compound C4) in the prevention of S. aureus biofilm formation was assessed. Compound C1 displayed a bimodal activity, hindering biofilm formation only at low concentrations and promoting biofilm growth at higher concentrations. In the case of C4, a dose-dependent inhibition of S. aureus biofilm growth was observed. Atomic force microscopy analysis suggested that at higher concentrations C1 formed globular aggregates, which perhaps formed a substratum that favored adhesion of cells and biofilm formation. In the case of C4, zinc supplementation experiments validated zinc complexation as a plausible mechanism of inhibition of S. aureus biofilm. Interestingly, C4 was nontoxic to cultured HeLa cells and thus has promise as a therapeutic anti-biofilm agent. The essential understanding of the structure-driven implications of zinc-complexing ligands acquired in this study might assist future screening regimes for identification of potent anti-biofilm agents. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Antimicrobial blue light inactivation of biofilms formed by clinical isolates of multidrug-resistant microorganisms

    Science.gov (United States)

    Ferrer-Espada, Raquel; Fang, Yanyan; Dai, Tianhong

    2018-02-01

    Antibiotic resistance is one of the most serious threats to public health. It is estimated that at least 23,000 people die each year in the USA as a direct result of antibiotic-resistant infections. In addition, many antibiotic-resistant microorganisms develop biofilms, surface-associated microbial communities that are extremely resistant to antibiotics and the immune system. A light-based approach, antimicrobial blue light (aBL), has attracted increasing attention due to its intrinsic antimicrobial effect without the involvement of exogenous photosensitizers. In this study, we investigated the effectiveness of this non-antibiotic approach against biofilms formed by multidrug-resistant (MDR) microorganisms. MDR Acinetobacter baumannii, Escherichia coli, Candida albicans, and Pseudomonas aeruginosa biofilms were grown either in 96-well microtiter plates for 24 h or in a CDC biofilm reactor for 48 h, and then exposed to aBL at 405 nm emitted from a light-emitting diode (LED). We demonstrated that, for the biofilms grown in the CDC biofilm reactor, approximately 1.88 log10 CFU reduction was achieved in A. baumannii, 2.78 log10 CFU in E. coli and 3.18 log10 CFU in P. aeruginosa after 162 J/cm2 , 576 J/cm2 and 500 J/cm2 aBL were delivered, respectively. For the biofilms formed in the 96-well microtiter plates, 5.67 and 2.46 log10 CFU reduction was observed in P. aeruginosa and C. albicans polymicrobial biofilm after an exposure of 216 J/cm2 . In conclusion, aBL is potentially an alternative non-antibiotic approach against MDR biofilm-related infections. Future studies are warranted to investigate other important MDR microorganisms, the mechanism of action of aBL, and aBL efficacy in vivo.

  17. The Biofilm Challenge

    DEFF Research Database (Denmark)

    Alhede, Maria; Alhede, Morten

    2014-01-01

    The concept of biofilms has emerged in the clinical setting during the last decade. Infections involving biofilms have been documented in all parts of the human body, and it is currently believed that the presence of biofilm-forming bacteria is equivalent to chronic infection. A quick Pubmed search...

  18. Produção de biofilme por leveduras isoladas de cavidade bucal de usuários de prótese dentária Biofilm production by yeasts isolated from bucal cavity of prosthesis wearers

    Directory of Open Access Journals (Sweden)

    Terezinha Inez Estivalet Svidzinski

    2005-03-01

    Full Text Available Foi analisada a presença de espécies do gênero Cândida na saliva de indivíduos distribuídos em três grupos: 1 com prótese e lesão; 2 com prótese sem lesão; 3 sem prótese e sem lesão, correlacionando com a capacidade de produção de biofilme em meio Sabouraud dextrose, contendo 8% de glicose, sendo determinada por leitura em espectrofotômetro. Dos 220 pacientes foram isoladas 92 leveduras: 24 (grupo 1, 24 (grupo 2 e 44 (grupo 3. Em 70% foi isolado C. albicans e 30% C. não albicans. A produção de biofilme em maior freqüência (64% foi encontrada entre as leveduras C. não albicans e a maior porcentagem na produção de biofilme, quanto aos grupos de pacientes, foram 75, 63 e 57% correspondendo aos grupos 1, 2 e 3, respectivamente. Esses dados sugerem que a produção de biofilme das espécies do gênero Cândida pode estar associada ao processo infeccioso destes isoladosThe presence of some species of Candida was analyzed in saliva of individuals with: 1 prostheses and lesions; 2 with prostheses without lesions; 3 without prostheses and without lesions, relating with the capacity for biofilm production in Sabouraud dextrose broth medium with 8% of glucose determinate by spectrophotometric method. A total of 92 yeasts were isolated from the 220 patients: 24 (group 1, 24 (group 2 and 44 (group 3. C. albicans was isolated in 70% of the cases and C. non albicans in 30%. The most frequent biofilm production (64% was showed by C. non albicans yeasts and the patient groups who presented greater percent in biofilm production was 1, 2 and 3 corresponding to 75, 63 e 57% respectively. These data support that biofilm production may be associated with infectious process caused by Candida species

  19. 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).

  20. 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.

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

    Science.gov (United States)

    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

  2. [Microbial "friend-foe" identification in human intestine microsymbiocenosis].

    Science.gov (United States)

    Bukharin, O V; Petrunova, N B

    2011-01-01

    Development of methodical approach of evaluation of microbial "friend-foe" identification in human intestine microsymbiocenosis. 9 bifidobacteria cultures (dominants) and 18 opportunistic microorganism strains (associants) isolated from patients during examination for intestine dysbiosis and identified by conventional methods were used. Evaluation of microbial "friend-foe" identification in microsymbiocenosis was performed by author developed technique that is based on determination of growth factors (GF), anti-lysozyme activity (ALA) and formation of biofilms (BFF) of associants co-incubated with exometabolites of dominants. GF, ALA, BFF were studied photometrically (Bukharin O.V., 1999, 2009; O'Toole G.A., 2000). The data were statistically analyzed by Fisher-Student criteria. The detected opposite (increase/reduction) phenomenon of the "dominant-associant" pair allowed realization of the "friend-foe" identification in microsymbiocenosis. Associants (E. coli and Enterococcus faecium) were "friend" species, in which bifidobacteria exometabolites did not change growth properties and stimulated ALA (by 17,5--32%) and BFF (by 25 - 39%). Associants (Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Candida albicans) were "foe" microsymbiont species, in which bifidoflora exometabolites decreased GF (by 20,7--68%), ALA (by 22,7--54%) and BFF (by 22,5 --39%). Indigenous microflora during microsymbiocenosis formation can participate in "friend-foe" identification, the basis of which is determined by microsymbiont exometabolites. The data obtained open a perspective of understanding mechanisms of intramicrobial interactions and can be used for both diagnostics and optimal selection of "candidates" during creation of new probiotics and synbiotics.

  3. Antifungal activity, mode of action and anti-biofilm effects of Laurus nobilis Linnaeus essential oil against Candida spp.

    Science.gov (United States)

    Peixoto, Larissa Rangel; Rosalen, Pedro Luiz; Ferreira, Gabriela Lacet Silva; Freires, Irlan Almeida; de Carvalho, Fabíola Galbiatti; Castellano, Lúcio Roberto; de Castro, Ricardo Dias

    2017-01-01

    The present study demonstrated the antifungal potential of the chemically characterized essential oil (EO) of Laurus nobilis L. (bay laurel) against Candida spp. biofilm adhesion and formation, and further established its mode of action on C. albicans. L. nobilis EO was obtained and tested for its minimum inhibitory and fungicidal concentrations (MIC/MFC) against Candida spp., as well as for interaction with cell wall biosynthesis and membrane ionic permeability. Then we evaluated its effects on the adhesion, formation, and reduction of 48hC. albicans biofilms. The EO phytochemical profile was determined by gas chromatography coupled to mass spectrometry (GC/MS). The MIC and MFC values of the EO ranged from (250 to 500) μg/mL. The MIC values increased in the presence of sorbitol (osmotic protector) and ergosterol, which indicates that the EO may affect cell wall biosynthesis and membrane ionic permeability, respectively. At 2 MIC the EO disrupted initial adhesion of C. albicans biofilms (p0.05). When applied for 1min, every 8h, for 24h and 48h, the EO reduced the amount of C. albicans mature biofilm with no difference in relation to nystatin (p>0.05). The phytochemical analysis identified isoeugenol as the major compound (53.49%) in the sample. L. nobilis EO has antifungal activity probably due to monoterpenes and sesquiterpenes in its composition. This EO may affect cell wall biosynthesis and membrane permeability, and showed deleterious effects against C. albicans biofilms. Copyright © 2016. Published by Elsevier Ltd.

  4. Influence of Culture Media on Biofilm Formation by Candida Species and Response of Sessile Cells to Antifungals and Oxidative Stress

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    Isela Serrano-Fujarte

    2015-01-01

    Full Text Available The aims of the study were to evaluate the influence of culture media on biofilm formation by C. albicans, C. glabrata, C. krusei, and C. parapsilosis and to investigate the responses of sessile cells to antifungals and reactive oxygen species (ROS as compared to planktonic cells. For biofilm formation, the Candida species were grown at different periods of time in YP or YNB media supplemented or not with 0.2 or 2% glucose. Sessile and planktonic cells were exposed to increasing concentrations of antifungals, H2O2, menadione or silver nanoparticles (AgNPs. Biofilms were observed by scanning electron microscopy (SEM and quantified by the XTT assay. C. albicans formed biofilms preferentially in YPD containing 2% glucose (YPD/2%, C. glabrata in glucose-free YNB or supplemented with 0.2% glucose (YNB/0.2%, while C. krusei and C. parapsilosis preferred YP, YPD/0.2%, and YPD/2%. Interestingly, only C. albicans produced an exopolymeric matrix. This is the first report dealing with the in vitro effect of the culture medium and glucose on the formation of biofilms in four Candida species as well as the resistance of sessile cells to antifungals, AgNPs, and ROS. Our results suggest that candidiasis in vivo is a multifactorial and complex process where the nutritional conditions, the human immune system, and the adaptability of the pathogen should be considered altogether to provide an effective treatment of the patient.

  5. Influence of Culture Media on Biofilm Formation by Candida Species and Response of Sessile Cells to Antifungals and Oxidative Stress

    Science.gov (United States)

    Serrano-Fujarte, Isela; Reyna-López, Georgina Elena; Martínez-Gámez, Ma. Alejandrina; Vega-González, Arturo; Cuéllar-Cruz, Mayra

    2015-01-01

    The aims of the study were to evaluate the influence of culture media on biofilm formation by C. albicans, C. glabrata, C. krusei, and C. parapsilosis and to investigate the responses of sessile cells to antifungals and reactive oxygen species (ROS) as compared to planktonic cells. For biofilm formation, the Candida species were grown at different periods of time in YP or YNB media supplemented or not with 0.2 or 2% glucose. Sessile and planktonic cells were exposed to increasing concentrations of antifungals, H2O2, menadione or silver nanoparticles (AgNPs). Biofilms were observed by scanning electron microscopy (SEM) and quantified by the XTT assay. C. albicans formed biofilms preferentially in YPD containing 2% glucose (YPD/2%), C. glabrata in glucose-free YNB or supplemented with 0.2% glucose (YNB/0.2%), while C. krusei and C. parapsilosis preferred YP, YPD/0.2%, and YPD/2%. Interestingly, only C. albicans produced an exopolymeric matrix. This is the first report dealing with the in vitro effect of the culture medium and glucose on the formation of biofilms in four Candida species as well as the resistance of sessile cells to antifungals, AgNPs, and ROS. Our results suggest that candidiasis in vivo is a multifactorial and complex process where the nutritional conditions, the human immune system, and the adaptability of the pathogen should be considered altogether to provide an effective treatment of the patient. PMID:25705688

  6. Influence of culture media on biofilm formation by Candida species and response of sessile cells to antifungals and oxidative stress.

    Science.gov (United States)

    Serrano-Fujarte, Isela; López-Romero, Everardo; Reyna-López, Georgina Elena; Martínez-Gámez, Ma Alejandrina; Vega-González, Arturo; Cuéllar-Cruz, Mayra

    2015-01-01

    The aims of the study were to evaluate the influence of culture media on biofilm formation by C. albicans, C. glabrata, C. krusei, and C. parapsilosis and to investigate the responses of sessile cells to antifungals and reactive oxygen species (ROS) as compared to planktonic cells. For biofilm formation, the Candida species were grown at different periods of time in YP or YNB media supplemented or not with 0.2 or 2% glucose. Sessile and planktonic cells were exposed to increasing concentrations of antifungals, H2O2, menadione or silver nanoparticles (AgNPs). Biofilms were observed by scanning electron microscopy (SEM) and quantified by the XTT assay. C. albicans formed biofilms preferentially in YPD containing 2% glucose (YPD/2%), C. glabrata in glucose-free YNB or supplemented with 0.2% glucose (YNB/0.2%), while C. krusei and C. parapsilosis preferred YP, YPD/0.2%, and YPD/2%. Interestingly, only C. albicans produced an exopolymeric matrix. This is the first report dealing with the in vitro effect of the culture medium and glucose on the formation of biofilms in four Candida species as well as the resistance of sessile cells to antifungals, AgNPs, and ROS. Our results suggest that candidiasis in vivo is a multifactorial and complex process where the nutritional conditions, the human immune system, and the adaptability of the pathogen should be considered altogether to provide an effective treatment of the patient.

  7. Antibiofilm potential of flavonoids extracted from Moringa oleifera seed coat against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans.

    Science.gov (United States)

    Onsare, J G; Arora, D S

    2015-02-01

    The increased microbial drug resistance due to biofilms and the side effects associated with the use of conventional drugs is still a major concern in the medical fraternity. This work evaluates the antibiofilm potential of flavonoids extracted from Moringa oleifera seed coat (SC) in search for green and effective alternatives for overcoming menace of biofilms. The study evaluated the minimum inhibitory concentration (MIC) of flavonoids against respective test organisms, inhibition of initial cell attachment as well as disruption of preformed biofilms and metabolic activity of treated biofilms. Mutagenicity and cytotoxicity as well as characterization of the active component were also carried out. Although Pseudomonas aeruginosa showed the lowest MIC of 0.05 mg ml(-1), the action of flavonoids and gentamicin on initial cell attachment revealed a comparable effect against bacterial biofilms, i.e. Staphylococcus aureus and Pseudomonas aeruginosa with approx. 80% inhibition compared to Candida albicans. Disruption of the preformed biofilms revealed that susceptibility of P. aeruginosa began as early as 4 h of exposure to flavonoids with 88% growth inhibition at the end of 24-h incubation. Encouragingly, t-test analysis on the effect of the extract and the standard antibiotic against each organism indicated no significant variance at P < 0.05. A drastic low metabolic activity exhibited by the treated biofilms as compared to the untreated ones was further supportive of the antibiofilm potential of seed coat flavonoids. The bioactive component from M. oleifera seed coat has exhibited antibiofilm potential against the test organisms belonging to Gram positive, Gram negative and yeast. Antibiofilm potential and biosafety of plant-based flavonoids from M. oleifera seed coat reveal a prospective active principle that could be of use in biofilm-associated menace. © 2014 The Society for Applied Microbiology.

  8. 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.

  9. Prevalence of Candida albicans, Candida dubliniensis and Candida africana in pregnant women suffering from vulvovaginal candidiasis in Argentina.

    Science.gov (United States)

    Mucci, María Josefina; Cuestas, María Luján; Landanburu, María Fernanda; Mujica, María Teresa

    Vulvovaginal candidiasis (VVC) is a vulvovaginitis commonly diagnosed in gynecology care. In recent years, the taxonomy of the most important pathogenic Candida species, such as Candida albicans have undergone significant changes. This study examined the prevalence of C. albicans, Candida africana, and Candida dubliniensis in vaginal specimens from 210 pregnant women suffering from vulvovaginitis or having asymptomatic colonization. Phenotypic and molecular methods were used for the identification of the species. During the studied period, 55 isolates of Candida or other yeasts were obtained from specimens collected from 52 patients suffering from vulvovaginitis (24.8%). C. albicans was the predominant Candida species in 42 isolates (80.7%), either alone or in combination with other species of the genus (5.7%, n=3). Additionally, nine isolates of C. albicans (50%) were obtained from asymptomatic patients (n=18). C. dubliniensis was the causative agent in 2 (3.8%) cases of VVC, and was also isolated in one asymptomatic patient. Molecular assays were carried out using specific PCR to amplify the ACT1-associated intron sequence of C. dubliniensis. The amplification of the HWP1 gene also correctly identified isolates of the species C. albicans and C. dubliniensis. No C. africana was isolated in this work. Some C. albicans isolates were either homozygous or heterozygous at the HWP1 locus. The distribution of heterozygous and homozygous C. albicans isolates at the HWP1 locus was very similar among patients suffering from VVC and asymptomatic patients (p=0.897). The presence of C. albicans and C. dubliniensis, and the absence of C. africana in pregnant is noteworthy. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. The Use of Chitosan to Enhance Photodynamic Inactivation against Candida albicans and Its Drug-Resistant Clinical Isolates

    Directory of Open Access Journals (Sweden)

    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.

  11. Intrinsic and Extrinsic Aspects on Campylobacter jejuni Biofilms

    Directory of Open Access Journals (Sweden)

    Roberta T. Melo

    2017-07-01

    Full Text Available Biofilm represents a way of life that allows greater survival of microorganisms in hostile habitats. Campylobacter jejuni is able to form biofilms in vitro and on surfaces at several points in the poultry production chain. Genetic determinants related to their formation are expressed differently between strains and external conditions are decisive in this respect. Our approach combines phylogenetic analysis and the presence of seven specific genes linked to biofilm formation in association with traditional microbiology techniques, using Mueller Hinton and chicken juice as substrates in order to quantify, classify, determine the composition and morphology of the biomass of simple and mixed biofilms of 30 C. jejuni strains. It also evaluates the inhibition of its formation by biocides commonly used in industry and also by zinc oxide nanoparticles. Genetic analysis showed high heterogeneity with the identification of 23 pulsotypes. Despite the diversity, the presence of flaA, cadF, luxS, dnaJ, htrA, cbrA, and sodB genes in all strains shows the high potential for biofilm formation. This ability was only expressed in chicken juice, where they presented phenotype of a strong biofilm producer, with a mean count of 7.37 log CFU/mL and an ultrastructure characteristic of mature biofilm. The composition of simple and mixed biofilms was predominantly composed by proteins. The exceptions were found in mixed biofilms with Pseudomonas aeruginosa, which includes a carbohydrate-rich matrix, lower ability to sessile form in chicken juice and compact architecture of the biofilm, this aspects are intrinsic to this species. Hypochlorite, chlorhexidine, and peracetic acid were more effective in controlling viable cells of C. jejuni in biofilm, but the existence of tolerant strains indicates exposure to sublethal concentrations and development of adaptation mechanisms. This study shows that in chicken juice C. jejuni presents greater potential in producing mature

  12. 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

  13. 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.

  14. Purification and identification of 4-allylbenzene-1,2-diol: an antilisterial and biofilm preventing compound from the leaves of Piper betle L. var Pachaikodi.

    Science.gov (United States)

    Kavitha, Sekar; HariKrishnan, Adhikesavan; Jeevaratnam, Kadirvelu

    2017-12-22

    Antibiotic-resistant food-borne Listeriosis has been rising with up to 30% mortality threat in humans since several decades. Hence, discovering antilisterial from the extracts of ethnomedicinal plants may be of value as a novel antidote. In our preceding study, we reported that ethanolic extract of Piper betle L. var Pachaikodi leaves exhibited antibacterial activity towards Listeria monocytogenes MTCC 657. Consequently in the present study, the bioactive molecule responsible for anti-Listeria activity was purified and identified as 4-allylbenzene-1,2-diol. This identified bioactive compound may have significance while used as antimicrobials and/or food additives in food processing sector as evidenced by dual action: biofilm inhibition and pore formation on cell membrane.

  15. Pseudomonas aeruginosa biofilm infections

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim

    2014-01-01

    Bacteria in natural, industrial and clinical settings predominantly live in biofilms, i.e., sessile structured microbial communities encased in self-produced extracellular matrix material. One of the most important characteristics of microbial biofilms is that the resident bacteria display...... a remarkable increased tolerance toward antimicrobial attack. Biofilms formed by opportunistic pathogenic bacteria are involved in devastating persistent medical device-associated infections, and chronic infections in individuals who are immune-compromised or otherwise impaired in the host defense. Because...... the use of conventional antimicrobial compounds in many cases cannot eradicate biofilms, there is an urgent need to develop alternative measures to combat biofilm infections. The present review is focussed on the important opportunistic pathogen and biofilm model organism Pseudomonas aeruginosa. Initially...

  16. Flo11p, drug efflux pumps, and the extracellular matrix cooperate to form biofilm yeast colonies

    Czech Academy of Sciences Publication Activity Database

    Váchová, Libuše; Šťovíček, V.; Hlaváček, Otakar; Chernyavskiy, Oleksandr; Štěpánek, L.; Kubínová, Lucie; Palková, Z.

    2011-01-01

    Roč. 194, č. 5 (2011), s. 679-687 ISSN 0021-9525 R&D Projects: GA ČR GA204/08/0718; GA MŠk(CZ) LC531; GA MŠk(CZ) LC06063 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z50110509 Keywords : CANDIDA-ALBICANS BIOFILMS * SACCHAROMYCES-CEREVISIAE * ABC TRANSPORTERS Subject RIV: EE - Microbiology, Virology Impact factor: 10.264, year: 2011

  17. High-Throughput Nano-Biofilm Microarray for Antifungal Drug Discovery

    Science.gov (United States)

    2013-06-25

    of metal ions. Toyocamycin is an adenosine analog that has shown tumori- cidal activity by inhibiting RNA synthesis and inducing apoptosis (44) and...copolymer esters as flow improvers of waxy crude oil. J. Petrol. Sci. Eng. 65:139 –146. 20. Kyeremateng SO, Amado E, Kressler J. 2007. Synthesis and...MA. 2003. Mecha- nism of fluconazole resistance in Candida albicans biofilms: phase-specific role of efflux pumps and membrane sterols . Infect. Immun

  18. Anti-Candida activity assessment of Pelargonium graveolens oil free and nanoemulsion in biofilm formation in hospital medical supplies.

    Science.gov (United States)

    Giongo, Janice Luehring; de Almeida Vaucher, Rodrigo; Fausto, Viviane Pedroso; Quatrin, Priscilla Maciel; Lopes, Leonardo Quintana Soares; Santos, Roberto Christ Vianna; Gündel, André; Gomes, Patrícia; Steppe, Martin

    2016-11-01

    Infections due to microbial biofilm formation on the surface of catheters and other medical devices are constantly reported as a major cause of morbidity and mortality in patients admitted to hospitals. Furthermore, sessile cells are more resistant to phagocytosis and most antimicrobial, which complicates the treatment of such infections. Researches aimed at new antimicrobial originating mainly from plants have increased in recent years and the development of new strategies for their release is critical in combating the formation of biofilms. Geranium oil (GO) has proven antimicrobial activity. Because of this, the aim of this study was to develop nanoemulsions containing this oil (NEG) and evaluate its activity after the biofilm formation of Candida albicans, Candida tropicalis, Candida glabrata, and Candida krusei in hospital medical supplies. For quantification of the biofilm, crystal violet, total protein, and ATP-bioluminescence assays were used. The results revealed that GO and NEG showed lower MIC for C. albicans and C. tropicalis. The biofilms formed by different species of Candida on the surfaces of polyethylene and polyurethane were quantified. GO and NEG significantly inhibited the formation of biofilms in all species tested on the surfaces of polyethylene. However, NEG antibiofilm has had better activity than GO for C. albicans, C. tropicalis and C. glabrata, according to the surface potential analysis by atomic force microscopy (AFM). The analysis of the biofilm formation on the polyethylene surface by ATP-bioluminescence and CFU showed similar results. In both methods the formation of biofilm in the catheter occurred in greater quantity for C. albicans and C. tropicalis. GO did not significantly inhibit the formation of biofilms only in C. krusei, although NEG significantly increased this activity GO in all species tested when compared to the control training biofilm. The following study shows that the development of NEG may become an effective

  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. Candida albicans infection in patients with oral squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Čanković Miloš

    2010-01-01

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

  1. 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...

  2. 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.

  3. 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.

  4. Voice Prosthetic Biofilm Formation and Candida Morphogenic Conversions in Absence and Presence of Different Bacterial Strains and Species on Silicone-Rubber

    NARCIS (Netherlands)

    van der Mei, Henny C.; Buijssen, Kevin J. D. A.; van der Laan, Bernard F. A. M.; Ovchinnikova, Ekatarina; Geertsema-Doornbusch, Gesinda I.; Atema-Smit, Jelly; van de Belt-Gritter, Betsy; Busscher, Henk J.

    2014-01-01

    Morphogenic conversion of Candida from a yeast to hyphal morphology plays a pivotal role in the pathogenicity of Candida species. Both Candida albicans and Candida tropicalis, in combination with a variety of different bacterial strains and species, appear in biofilms on silicone-rubber voice

  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. Long-term efficacy of denture cleansers in preventing Candida spp. biofilm recolonization on liner surface

    Directory of Open Access Journals (Sweden)

    Ana Paula Coelho Vieira

    2010-09-01

    Full Text Available This study evaluated the long-term efficacy of denture cleansers against Candida spp. biofilm recolonization on liner surface. Specimens were fabricated of a poly(methyl methacrylate-based denture liner and had their surface roughness evaluated at baseline and after cleansing treatments. C. albicans or C. glabrata biofilms were formed on liner surface for 48 h, and then the specimens were randomly assigned to one of cleaning treatments: two alkaline peroxides (soaking for 3 or 15 min, 0.5% sodium hypochlorite (10 min or distilled water (control; 15 min. After the treatments, the specimens were sonicated to disrupt the biofilm, and residual cells were counted (cell/mL. Long-term effectiveness of the cleaning processes was determined by submitting a set of cleaned specimens to biofilm growth conditions for 48 h followed by estimation of cell counts. The topography of specimens after cleaning treatments was analyzed by SEM. Data were analyzed by ANOVA and Tukey's test (α; = 0.05. Results of cell count estimation showed significant differences in cleanliness among the treatments (p 0.05 was observed among the Candida species regarding the recolonization condition. Alkaline denture cleansers showed similar cleaning performance and both differed from the control (p < 0.001. Sodium hypochlorite was the only treatment that removed biofilm efficiently, since no viable cells were found after its use. In conclusion, alkaline peroxide denture cleansers were not effective in removing Candida spp. biofilm from denture liner surfaces and preventing biofilm recolonization.

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

    Directory of Open Access Journals (Sweden)

    Bernadett Márkus

    suggested a role for CaPpz1 in biofilm formation, was confirmed experimentally. Thus our unbiased proteomic approach lead to the discovery of a novel function for this phosphatase in C. albicans.

  8. 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

    CaPpz1 in biofilm formation, was confirmed experimentally. Thus our unbiased proteomic approach lead to the discovery of a novel function for this phosphatase in C. albicans. PMID:28837603

  9. Photodynamic therapy with water-soluble phtalocyanines against bacterial biofilms in teeth root canals

    Science.gov (United States)

    Gergova, Raina; Georgieva, Tzvetelina; Angelov, Ivan; Mantareva, Vanya; Valkanov, Serjoga; Mitov, Ivan; Dimitrov, Slavcho

    2012-06-01

    The study presents the PDT with metal phthalocyanines on biofilms grown in root canals of ten representatives of the Gram-positive and the Gram-negative bacterial species and a fungus Candida albicans which cause aqute teeth infections in root canals.. The extracted human single-root teeth infected for 48 h with microorganisms in conditions to form biofilms of the above pathogens were PDT treated. The stage of biofilm formation and PDT effect of the samples of the teeth were determined by the scaning electron microscopy and with standard microbial tests. The PDT treating procedure included 10 min incubation with the respected phthalocyanine and irradiated with 660 nm Diode laser for 10 min. The most strongly antibacterial activity was achieved with zinc(II) phthalocyanine (ZnPc) against Enterococcus faecalis, Staphylococcus aureus and Moraxella catarrhalis. The other Gram-negative bacteria and Candida albicans were 10-100 times more resistant than the Gram-positive species. The Gram-negative Moraxella catarrhalis and Acinetobacter baumannii were more sensitive than the enterobacteria, but eradication of Pseudomonas aeruginosa in biofilm was insignificant. The influence of the stage of biofilm formation and the initial conditions (bacterial density, photosensitizer concentration and energy fluence of radiation) to the obtained level of inactivation of biofilms was investigated. The PDT with ZnPc photosensitizers show a powerful antimicrobial activity against the most frequent pathogens in endodontic infections and this method for inactivation of pathogens may be used with sucsses for treatment of the bacterial biofilms in the root canals.

  10. Hydraulic resistance of biofilms

    KAUST Repository

    Dreszer, C.

    2013-02-01

    Biofilms may interfere with membrane performance in at least three ways: (i) increase of the transmembrane pressure drop, (ii) increase of feed channel (feed-concentrate) pressure drop, and (iii) increase of transmembrane passage. Given the relevance of biofouling, it is surprising how few data exist about the hydraulic resistance of biofilms that may affect the transmembrane pressure drop and membrane passage. In this study, biofilms were generated in a lab scale cross flow microfiltration system at two fluxes (20 and 100Lm-2h-1) and constant cross flow (0.1ms-1). As a nutrient source, acetate was added (1.0mgL-1 acetate C) besides a control without nutrient supply. A microfiltration (MF) membrane was chosen because the MF membrane resistance is very low compared to the expected biofilm resistance and, thus, biofilm resistance can be determined accurately. Transmembrane pressure drop was monitored. As biofilm parameters, thickness, total cell number, TOC, and extracellular polymeric substances (EPS) were determined, it was demonstrated that no internal membrane fouling occurred and that the fouling layer actually consisted of a grown biofilm and was not a filter cake of accumulated bacterial cells. At 20Lm-2h-1 flux with a nutrient dosage of 1mgL-1 acetate C, the resistance after 4 days reached a value of 6×1012m-1. At 100Lm-2h-1 flux under the same conditions, the resistance was 5×1013m-1. No correlation of biofilm resistance to biofilm thickness was found; Biofilms with similar thickness could have different resistance depending on the applied flux. The cell number in biofilms was between 4×107 and 5×108 cellscm-2. At this number, bacterial cells make up less than a half percent of the overall biofilm volume and therefore did not hamper the water flow through the biofilm significantly. A flux of 100Lm-2h-1 with nutrient supply caused higher cell numbers, more biomass, and higher biofilm resistance than a flux of 20Lm-2h-1. However, the biofilm thickness

  11. First characterization of Candida albicans by random amplified polymorphic DNA method in Nicaragua and comparison of the diagnosis methods for vaginal candidiasis in Nicaraguan women

    Directory of Open Access Journals (Sweden)

    Bello Martha Darce

    2002-01-01

    Full Text Available A total of 106 women with vaginitis in Nicaragua were studied. The positive rate for the identification of Candida species was 41% (44 positive cultures out of 106 women with vaginitis. The sensitivity of microscopic examination of wet mount with the potassium hydroxide (KOH was 61% and 70% with Gram's stain when using the culture of vaginal fluid as gold standard for diagnosis of candidiasis. Among the 44 positives cultures, isolated species of yeast from vaginal swabs were C. albicans (59%, C. tropicalis (23%, C. glabrata (14% and C. krusei (4%. This study reports the first characterization of 26 C. albicans stocks from Nicaragua by the random amplified polymorphic DNA method. The genetic analysis in this small C. albicans population showed the existence of linkage disequilibrium, which is consistent with the hypothesis that C. albicans undergoes a clonal propagation.

  12. 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.

  13. 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

  14. Meningococcal biofilm formation

    DEFF Research Database (Denmark)

    Lappann, M.; Haagensen, Janus Anders Juul; Claus, H.

    2006-01-01

    We show that in a standardized in vitro flow system unencapsulated variants of genetically diverse lineages of Neisseria meningitidis formed biofilms, that could be maintained for more than 96 h. Biofilm cells were resistant to penicillin, but not to rifampin or ciprofloxacin. For some strains......, microcolony formation within biofilms was observed. Microcolony formation in strain MC58 depended on a functional copy of the pilE gene encoding the pilus subunit pilin, and was associated with twitching of cells. Nevertheless, unpiliated pilE mutants formed biofilms showing that attachment and accumulation......X alleles was identified among genetically diverse meningococcal strains. PilX alleles differed in their propensity to support autoaggregation of cells in suspension, but not in their ability to support microcolony formation within biofilms in the continuous flow system....

  15. Biofilms in wounds

    DEFF Research Database (Denmark)

    Cooper, R A; Bjarnsholt, Thomas; Alhede, M

    2014-01-01

    Following confirmation of the presence of biofilms in chronic wounds, the term biofilm became a buzzword within the wound healing community. For more than a century pathogens have been successfully isolated and identified from wound specimens using techniques that were devised in the nineteenth...... extracellular polymeric substances (EPS). Cells within such aggregations (or biofilms) display varying physiological and metabolic properties that are distinct from those of planktonic cells, and which contribute to their persistence. There are many factors that influence healing in wounds and the discovery...... of biofilms in chronic wounds has provided new insight into the reasons why. Increased tolerance of biofilms to antimicrobial agents explains the limited efficacy of antimicrobial agents in chronic wounds and illustrates the need to develop new management strategies. This review aims to explain the nature...

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

    Directory of Open Access Journals (Sweden)

    Voon Kin Chin

    2016-10-01

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

  17. Identification of a General O-linked Protein Glycosylation System in Acinetobacter baumannii and Its Role in Virulence and Biofilm Formation

    Science.gov (United States)

    Iwashkiw, Jeremy A.; Seper, Andrea; Weber, Brent S.; Scott, Nichollas E.; Vinogradov, Evgeny; Stratilo, Chad; Reiz, Bela; Cordwell, Stuart J.; Whittal, Randy; Schild, Stefan; Feldman, Mario F.

    2012-01-01

    Acinetobacter baumannii is an emerging cause of nosocomial infections. The isolation of strains resistant to multiple antibiotics is increasing at alarming rates. Although A. baumannii is considered as one of the more threatening “superbugs” for our healthcare system, little is known about the factors contributing to its pathogenesis. In this work we show that A. baumannii ATCC 17978 possesses an O-glycosylation system responsible for the glycosylation of multiple proteins. 2D-DIGE and mass spectrometry methods identified seven A. baumannii glycoproteins, of yet unknown function. The glycan structure was determined using a combination of MS and NMR techniques and consists of a branched pentasaccharide containing N-acetylgalactosamine, glucose, galactose, N-acetylglucosamine, and a derivative of glucuronic acid. A glycosylation deficient strain was generated by homologous recombination. This strain did not show any growth defects, but exhibited a severely diminished capacity to generate biofilms. Disruption of the glycosylation machinery also resulted in reduced virulence in two infection models, the amoebae Dictyostelium discoideum and the larvae of the insect Galleria mellonella, and reduced in vivo fitness in a mouse model of peritoneal sepsis. Despite A. baumannii genome plasticity, the O-glycosylation machinery appears to be present in all clinical isolates tested as well as in all of the genomes sequenced. This suggests the existence of a strong evolutionary pressure to retain this system. These results together indicate that O-glycosylation in A. baumannii is required for full virulence and therefore represents a novel target for the development of new antibiotics. PMID:22685409

  18. Identification of a general O-linked protein glycosylation system in Acinetobacter baumannii and its role in virulence and biofilm formation.

    Directory of Open Access Journals (Sweden)

    Jeremy A Iwashkiw

    Full Text Available Acinetobacter baumannii is an emerging cause of nosocomial infections. The isolation of strains resistant to multiple antibiotics is increasing at alarming rates. Although A. baumannii is considered as one of the more threatening "superbugs" for our healthcare system, little is known about the factors contributing to its pathogenesis. In this work we show that A. baumannii ATCC 17978 possesses an O-glycosylation system responsible for the glycosylation of multiple proteins. 2D-DIGE and mass spectrometry methods identified seven A. baumannii glycoproteins, of yet unknown function. The glycan structure was determined using a combination of MS and NMR techniques and consists of a branched pentasaccharide containing N-acetylgalactosamine, glucose, galactose, N-acetylglucosamine, and a derivative of glucuronic acid. A glycosylation deficient strain was generated by homologous recombination. This strain did not show any growth defects, but exhibited a severely diminished capacity to generate biofilms. Disruption of the glycosylation machinery also resulted in reduced virulence in two infection models, the amoebae Dictyostelium discoideum and the larvae of the insect Galleria mellonella, and reduced in vivo fitness in a mouse model of peritoneal sepsis. Despite A. baumannii genome plasticity, the O-glycosylation machinery appears to be present in all clinical isolates tested as well as in all of the genomes sequenced. This suggests the existence of a strong evolutionary pressure to retain this system. These results together indicate that O-glycosylation in A. baumannii is required for full virulence and therefore represents a novel target for the development of new antibiotics.

  19. [The evaluation of relationship between the origin of Candida sp. and the ability of biofilm formation on surface of different biomaterials].

    Science.gov (United States)

    Ciok-Pater, Emilia; Gospodarek, Eugenia; Prazyńska, Małgorzata; Bogiel, Tomasz

    2009-01-01

    The increase of fungal infections in recent years is connected with the progress in medicine. The vast usage of biomaterials is an inseparable element of contemporary medicine but it also leads to development of infections. The ability to produce biofilm by those yeasts plays an important role in the pathogenesis of candidiasis. Candida biofilm can form on the surface of plastic materials (silicon, polychloride vinyl, polymethacrylate methyl) used to catheters, drains and dentures production that is why it is a serious problem in case of fungal infections in patients who during the diagnosis and treatment have contact with biomaterials. The aim of the study was the assessment of ability to form biofilm on the surface of different biomaterials (latex silicon, polychloride vinyl, polystyrene, nylon and polymethacrylate methyl). 150 strains of Candida sp. were examined: 85 (56.7%) C. albicans and 65 (43.3%) C. non-albicans. The examined yeasts produced biofilm on the surface of polymethacrylate methyl in 39.3%, latex silicone in 38.7%, polychloride vinyl in 38.0%, polystyrene in 35.3% and nylon in 30.7%. Biofilm was most frequently produced by the strains of C. albicans, C. tropicalis, C. glabrata, C. parapsilosis, C. krusei and C. lusitaniae species.

  20. 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

  1. Sustained release of a novel anti-quorum-sensing agent against oral fungal biofilms.

    Science.gov (United States)

    Feldman, Mark; Shenderovich, Julia; Al-Quntar, Abed Al Aziz; Friedman, Michael; Steinberg, Doron

    2015-04-01

    Thiazolidinedione-8 (S-8) has recently been identified as a potential anti-quorum-sensing/antibiofilm agent against bacteria and fungi. Based on these results, we investigated the possibility of incorporating S-8 in a sustained-release membrane (SRM) to increase its pharmaceutical potential against Candida albicans biofilm. We demonstrated that SRM containing S-8 inhibits fungal biofilm formation in a time-dependent manner for 72 h, due to prolonged release of S-8. Moreover, the SRM effectively delivered the agent in its active form to locations outside the membrane reservoir. In addition, eradication of mature biofilm by the SRM containing S-8 was also significant. Of note, S-8-containing SRM affected the characteristics of mature C. albicans biofilm, such as thickness, exopolysaccharide (EPS) production, and morphogenesis of fungal cells. The concept of using an antibiofilm agent with no antifungal activity incorporated into a sustained-release delivery system is new in medicine and dentistry. This concept of an SRM containing a quorum-sensing quencher with an antibiofilm effect could pave the way for combating oral fungal infectious diseases. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  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. Chlamydospore production and germ-tube formation by auxotrophs of Candida albicans.

    Science.gov (United States)

    Balish, E

    1973-04-01

    A prototrophic strain and 21 auxotrophic strains of Candida albicans were assessed for their capacity to produce chlamydospores and germ tubes. All of the mutants were able to produce germ-tubes in human serum but only two mutants produced them in defined medium with L-alpha-amino-n-butyric acid as the sole source of nitrogen. Most auxotrophs were not able to produce chlamydospores on corn meal agar with 1% Tween 80, but they could be induced to do so if the medium was supplemented with their growth requirement(s). Although L-cysteine was able to support the growth of two methionine mutants, it did not support chlamydospore formation when added to corn meal agar with 1% Tween 80. Mutants of C. albicans that do not form chlamydospores could be incorrectly identified in laboratories that rely on chlamydospore formation for identification.

  7. Starvation, Together with the SOS Response, Mediates High Biofilm-Specific Tolerance to the Fluoroquinolone Ofloxacin

    Science.gov (United States)

    Bernier, Steve P.; Lebeaux, David; DeFrancesco, Alicia S.; Valomon, Amandine; Soubigou, Guillaume; Coppée, Jean-Yves; Ghigo, Jean-Marc; Beloin, Christophe

    2013-01-01

    High levels of antibiotic tolerance are a hallmark of bacterial biofilms. In contrast to well-characterized inherited antibiotic resistance, molecular mechanisms leading to reversible and transient antibiotic tolerance displayed by biofilm bacteria are still poorly understood. The physiological heterogeneity of biofilms influences the formation of transient specialized subpopulations that may be more tolerant to antibiotics. In this study, we used random transposon mutagenesis to identify biofilm-specific tolerant mutants normally exhibited by subpopulations located in specialized niches of heterogeneous biofilms. Using Escherichia coli as a model organism, we demonstrated, through identification of amino acid auxotroph mutants, that starved biofilms exhibited significantly greater tolerance towards fluoroquinolone ofloxacin than their planktonic counterparts. We demonstrated that the biofilm-associated tolerance to ofloxacin was fully dependent on a functional SOS response upon starvation to both amino acids and carbon source and partially dependent on the stringent response upon leucine starvation. However, the biofilm-specific ofloxacin increased tolerance did not involve any of the SOS-induced toxin–antitoxin systems previously associated with formation of highly tolerant persisters. We further demonstrated that ofloxacin tolerance was induced as a function of biofilm age, which was dependent on the SOS response. Our results therefore show that the SOS stress response induced in heterogeneous and nutrient-deprived biofilm microenvironments is a molecular mechanism leading to biofilm-specific high tolerance to the fluoroquinolone ofloxacin. PMID:23300476

  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. Biofilm is a Major Virulence Determinant in Bacterial Colonization of Chronic Skin Ulcers Independently from the Multidrug Resistant Phenotype

    Directory of Open Access Journals (Sweden)

    Enea Gino Di Domenico

    2017-05-01

    Full Text Available Bacterial biofilm is a major factor in delayed wound healing and high levels of biofilm production have been repeatedly described in multidrug resistant organisms (MDROs. Nevertheless, a quantitative correlation between biofilm production and the profile of antimicrobial drug resistance in delayed wound healing remains to be determined. Microbial identification, antibiotic susceptibility and biofilm production were assessed in 135 clinical isolates from 87 patients. Gram-negative bacteria were the most represented microorganisms (60.8% with MDROs accounting for 31.8% of the total isolates. Assessment of biofilm production revealed that 80% of the strains were able to form biofilm. A comparable level of biofilm production was found with both MDRO and not-MDRO with no significant differences between groups. All the methicillin-resistant Staphylococcus aureus (MRSA and 80% of Pseudomonas aeruginosa MDR strains were found as moderate/high biofilm producers. Conversely, less than 17% of Klebsiella pneumoniae extended-spectrum beta-lactamase (ESBL, Escherichia coli-ESBL and Acinetobacter baumannii were moderate/high biofilm producers. Notably, those strains classified as non-biofilm producers, were always associated with biofilm producer bacteria in polymicrobial colonization. This study shows that biofilm producers were present in all chronic skin ulcers, suggesting that biofilm represents a key virulence determinant in promoting bacterial persistence and chronicity of ulcerative lesions independently from the MDRO phenotype.

  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. Screening of pharmacologically active small molecule compounds identifies antifungal agents against Candida biofilms

    Directory of Open Access Journals (Sweden)

    Takao eWatamoto

    2015-12-01

    Full Text Available Candida species have emerged as important and common opportunistic human pathogens, particularly in immunocompromised individuals. The current antifungal therapies either have toxic side effects or are insufficiently effect. The aim of this study is develop new small-molecule antifungal compounds by library screening methods using C. albicans, and to evaluate their antifungal effects on Candida biofilms and cytotoxic effects on human cells. Wild-type C. albicans strain SC5314 was used in library screening. To identify antifungal compounds, we screened a small-molecule library of 1,280 pharmacologically active compounds (LOPAC1280TM using an antifungal susceptibility test (AST. To investigate the antifungal effects of the hit compounds, ASTs were conducted using Candida strains in various growth modes, including biofilms. We tested the cytotoxicity of the hit compounds using human gingival fibroblast (hGF cells to evaluate their clinical safety. Only 35 compounds were identified by screening, which inhibited the metabolic activity of C. albicans by >50%. Of these, 26 compounds had fungistatic effects and 9 compounds had fungicidal effects on C. albicans. Five compounds, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate, ellipticine and CV-3988, had strong fungicidal effects and could inhibit the metabolic activity of Candida biofilms. However, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate and ellipticine were cytotoxic to hGF cells at low concentrations. CV-3988 showed no cytotoxicity at a fungicidal concentration.Four of the compounds identified, BAY11-7082, BAY11-7085, sanguinarine chloride hydrate and ellipticine, had toxic effects on Candida strains and hGF cells. In contrast, CV-3988 had fungicidal effects on Candida strains, but low cytotoxic effects on hGF cells. Therefore, this screening reveals agent, CV-3988 that was previously unknown to be antifungal agent, which could be a novel therapies for superficial mucosal

  12. Comparison of duplex PCR and phenotypic analysis in differentiating Candida dubliniensis from Candida albicans from oral samples.

    Science.gov (United States)

    Sampath, Asanga; Weerasekera, Manjula; Dilhari, Ayomi; Gunasekara, Chinthika; Bulugahapitiya, Uditha; Fernando, Neluka; Samaranayake, Lakshman

    2017-12-01

    Candida dubliniensis shares a wide range of phenotypic characteristics with Candida albicans including a common trait called germ tube positivity. Hence, laboratory differentiation of these two species is cumbersome. Duplex PCR analyses for C. albicans and C. dubliniensis was performed directly on DNA extracted from a total of 122 germ tube positive isolates derived from 100 concentrated oral rinse samples from a random cohort of diabetics attending a clinic in Sri Lanka. These results were confirmed by DNA sequencing of internal transcribed spacer (ITS) region of rDNA of the yeasts. Performance efficacy of duplex PCR was then compared with phenotypic identification using a standard battery of phenotypic tests. Of the 122 germ tube positive isolates three were identified by duplex PCR as C. dubliniensis and the remainder as C. albicans. On the contrary, when the standard phenotypic tests, sugar assimilation and chlamydospore formation, were used to differentiate the two species 13 germ tube positive isolates were erroneously identified as C. dubliniensis. Duplex PCR was found to be rapid, sensitive and more specific than phenotypic identification methods in discriminating C. dubliniensis from C. albicans. This is also the first report on the oral carriage of C. dubliniensis in a Sri Lankan population.

  13. Emergence of non-albicans Candida among candidal vulvovaginitis cases and study of their potential virulence factors, from a tertiary care center, North India.

    Science.gov (United States)

    Kumari, Varsha; Banerjee, Tuhina; Kumar, Pankaj; Pandey, Sulekha; Tilak, Ragini

    2013-01-01

    The purpose of this study was to determine the prevalence of various Candida species and study some of their virulence factors among thevulvovaginal candidiasis(VVC)patients. The study was conducted in a Tertiary Care University Hospital in North India. This study was carried out prospectively for a period of 1 year. High vaginal swabs (HVSs) were collected from women in childbearing age group attending the gynecology and obstetrics out-patient departments with the complaints suggestive of vulvovaginitis. Samples were plated on Sabouraud's dextrose agar slope. Candida spp. isolated was further speciated based on microscopy, biochemical tests and culture characteristics on special media. Virulence factors of these strains were determined by biofilm formation and phospholipase activity. A total of 464 HVS from 232 patients with the complaints of vulvovaginitis were included in this study. Following laboratory workup, 71 specimens were positive for genus Candida (30.6%). Further speciation showed 32.4% as Candida albicans, 45.07% Candida parapsilosis and 22.53% of Candida glabrata. Biofilm production was shown by 50 candidal strains (70.4%) and phospholipase activity was given by 41 candidal strains (57.74%). Our study suggests increasing prevalence of non-albicans Candida among the VVC cases along with their virulence factors. Therefore, we recommend that microbiological investigation upto species level should be mandatory to determine the emergence of non-albicans Candida as a major cause of VVC.

  14. Emergence of non-albicans Candida among candidal vulvovaginitis cases and study of their potential virulence factors, from a tertiary care center, North India

    Directory of Open Access Journals (Sweden)

    Varsha Kumari

    2013-01-01

    Full Text Available Purpose: The purpose of this study was to determine the prevalence of various Candida species and study some of their virulence factors among thevulvovaginal candidiasis(VVCpatients. Study Design and Settings: The study was conducted in a Tertiary Care University Hospital in North India. Materials and Methods: This study was carried out prospectively for a period of 1 year. High vaginal swabs (HVSs were collected from women in childbearing age group attending the gynecology and obstetrics out-patient departments with the complaints suggestive of vulvovaginitis. Samples were plated on Sabouraud′s dextrose agar slope. Candida spp. isolated was further speciated based on microscopy, biochemical tests and culture characteristics on special media. Virulence factors of these strains were determined by biofilm formation and phospholipase activity. Result: A total of 464 HVS from 232 patients with the complaints of vulvovaginitis were included in this study. Following laboratory workup, 71 specimens were positive for genus Candida (30.6%. Further speciation showed 32.4% as Candida albicans, 45.07% Candida parapsilosis and 22.53% of Candida glabrata. Biofilm production was shown by 50 candidal strains (70.4% and phospholipase activity was given by 41 candidal strains (57.74%. Conclusion: Our study suggests increasing prevalence of non-albicans Candida among the VVC cases along with their virulence factors. Therefore, we recommend that microbiological investigation upto species level should be mandatory to determine the emergence of non-albicans Candida as a major cause of VVC.

  15. 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

  16. 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

  17. 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...

  18. Occurrence of yeasts, enterococci and other enteric bacteria in subgingival biofilm of HIV-positive patients with chronic gingivitis and necrotizing periodontitis Ocorrência de leveduras, enterococos e outras bactérias entéricas no biofilme subgengival de pacientes HIV-positivos com gengivite crônica e periodontite necrosante

    Directory of Open Access Journals (Sweden)

    Elerson Gaetti-Jardim Júnior

    2008-06-01

    Full Text Available The purpose of this study was to determine the prevalence of enteric bacteria and yeasts in biofilm of 80 HIV-positive patients with plaque-associated gingivitis or necrotizing periodontitis. Patients were subjected to extra, intra oral and radiographic examinations. The oral hygiene, bleeding on probing, gingival conditions, and attachment loss were evaluated. Clinical specimens were collected from gingival crevices or periodontal pockets, transferred to VMGA III, diluted and transferred to Sabouraud Dextrose agar with 100 µg/ml of chloramphenicol, peptone water, EVA broth, EMB agar, SS agar, Bile esculin agar and Brilliant green agar. Isolation of yeasts was carried out at room temperature, for 3-7 days; and for the isolation of enteric microorganisms plates were incubated at 37ºC, for 24-48 h. The yeasts identification was performed according to the carbon and nitrogen assimilation, fermentation of carbohydrates and germ tube formation. Bacteria were identified according to their colonial and cellular morphologies and biochemical tests. Yeasts were identified as Candida albicans and its occurrence was more common in patients with CD4+ below 200/mm³ and was affected by the extension of periodontal involvement (P = 0.0345. Enteric bacteria recovered from clinical specimens were identified as Enterobacter sakazakii, Enterobacter cloacae, Serratia liquefaciens, Klebsiella oxytoca and Enterococcus sp. Enterobacteriaceae and enterococci were detected in 32.5% of clinical samples from patients with necrotizing periodontitis. In conclusion, non-oral pathogenic bacteria and C. albicans were more prevalent in periodontal sites of HIV-positive patients with necrotizing periodontitis and chronic gingivitis.O objetivo desse estudo foi avaliar a ocorrência de bactérias entéricas e leveduras no biofilme subgengival de pacientes HIV-positivos com gengivite crônica ou periodontite necrosante. Os pacientes foram submetidos a exame clínico e radiogr

  19. Studying bacterial multispecies biofilms

    DEFF Research Database (Denmark)

    Røder, Henriette Lyng; Sørensen, Søren Johannes; Burmølle, Mette

    2016-01-01

    The high prevalence and significance of multispecies biofilms have now been demonstrated in various bacterial habitats with medical, industrial, and ecological relevance. It is highly evident that several species of bacteria coexist and interact in biofilms, which highlights the need for evaluating...... the approaches used to study these complex communities. This review focuses on the establishment of multispecies biofilms in vitro, interspecies interactions in microhabitats, and how to select communities for evaluation. Studies have used different experimental approaches; here we evaluate the benefits...... and drawbacks of varying the degree of complexity. This review aims to facilitate multispecies biofilm research in order to expand the current limited knowledge on interspecies interactions. Recent technological advances have enabled total diversity analysis of highly complex and diverse microbial communities...

  20. Compaction and relaxation of biofilms

    KAUST Repository

    Valladares Linares, R.

    2015-06-18

    Operation of membrane systems for water treatment can be seriously hampered by biofouling. A better characterization of biofilms in membrane systems and their impact on membrane performance may help to develop effective biofouling control strategies. The objective of this study was to determine the occurrence, extent and timescale of biofilm compaction and relaxation (decompaction), caused by permeate flux variations. The impact of permeate flux changes on biofilm thickness, structure and stiffness was investigated in situ and non-destructively with optical coherence tomography using membrane fouling monitors operated at a constant crossflow velocity of 0.1 m s−1 with permeate production. The permeate flux was varied sequentially from 20 to 60 and back to 20 L m−2 h−1. The study showed that the average biofilm thickness on the membrane decreased after elevating the permeate flux from 20 to 60 L m−2 h−1 while the biofilm thickness increased again after restoring the original flux of 20 L m−2 h−1, indicating the occurrence of biofilm compaction and relaxation. Within a few seconds after the flux change, the biofilm thickness was changed and stabilized, biofilm compaction occurred faster than the relaxation after restoring the original permeate flux. The initial biofilm parameters were not fully reinstated: the biofilm thickness was reduced by 21%, biofilm stiffness had increased and the hydraulic biofilm resistance was elevated by 16%. Biofilm thickness was related to the hydraulic biofilm resistance. Membrane performance losses are related to the biofilm thickness, density and morphology, which are influenced by (variations in) hydraulic conditions. A (temporarily) permeate flux increase caused biofilm compaction, together with membrane performance losses. The impact of biofilms on membrane performance can be influenced (increased and reduced) by operational parameters. The article shows that a (temporary) pressure increase leads to more

  1. Interactions in multispecies biofilms

    DEFF Research Database (Denmark)

    Burmølle, Mette; Ren, Dawei; Bjarnsholt, Thomas

    2014-01-01

    The recent focus on complex bacterial communities has led to the recognition of interactions across species boundaries. This is particularly pronounced in multispecies biofilms, where synergistic interactions impact the bacterial distribution and overall biomass produced. Importantly, in a number...... of settings, the interactions in a multispecies biofilm affect its overall function, physiology, or surroundings, by resulting in enhanced resistance, virulence, or degradation of pollutants, which is of significant importance to human health and activities. The underlying mechanisms causing these synergistic...

  2. The Impact of Biofilm Formation on the Persistence of Candidemia

    Directory of Open Access Journals (Sweden)

    Wei-Sin Li

    2018-06-01

    Full Text Available This study aimed to determine the predictors of persistent candidemia and examine the impact of biofilm formation by Candida isolates in adult patients with candidemia. Of the adult patients with candidemia in Kaohsiung Chang Gung Memorial Hospital between January 2007 and December 2012, 68 case patients with persistent candidemia (repeated candidemia after a 3-day systemic antifungal therapy and 68 control patients with non-persistent candidemia (Candida clearance from the bloodstream after a 3-day systemic antifungal therapy were included based on propensity score matching and matching for the Candida species isolated. Biofilm formation by the Candida species was assessed in vitro using standard biomass assays. Presence of central venous catheters (CVCs at diagnosis (adjusted odd ratio [AOR], 3.77; 95% confidence interval [CI], 1.09–13.00, p = 0.04, infection with higher biofilm forming strains of Candida species (AOR, 8.03; 95% CI, 2.50–25.81; p < 0.01, and receipt of suboptimal fluconazole doses as initial therapy (AOR, 5.54; 95% CI, 1.53–20.10; p < 0.01 were independently associated with persistent candidemia. Biofilm formation by Candida albicans, C. tropicalis, and C. glabrata strains was significantly higher in the case patients than in the controls. There were no significant differences in the overall mortality and duration of hospitalization between the two groups. Our data suggest that, other than presence of retained CVCs and use of suboptimal doses of fluconazole, biofilm formation was highly associated with development of persistent candidemia.

  3. Bacteriophages and Biofilms

    Directory of Open Access Journals (Sweden)

    David R. Harper

    2014-06-01

    Full Text Available Biofilms are an extremely common adaptation, allowing bacteria to colonize hostile environments. They present unique problems for antibiotics and biocides, both due to the nature of the extracellular matrix and to the presence within the biofilm of metabolically inactive persister cells. Such chemicals can be highly effective against planktonic bacterial cells, while being essentially ineffective against biofilms. By contrast, bacteriophages seem to have a greater ability to target this common form of bacterial growth. The high numbers of bacteria present within biofilms actually facilitate the action of bacteriophages by allowing rapid and efficient infection of the host and consequent amplification of the bacteriophage. Bacteriophages also have a number of properties that make biofilms susceptible to their action. They are known to produce (or to be able to induce enzymes that degrade the extracellular matrix. They are also able to infect persister cells, remaining dormant within them, but re-activating when they become metabolically active. Some cultured biofilms also seem better able to support the replication of bacteriophages than comparable planktonic systems. It is perhaps unsurprising that bacteriophages, as the natural predators of bacteria, have the ability to target this common form of bacterial life.

  4. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.)

  7. Identification of Carbohydrate Metabolism Genes in the Metagenome of a Marine Biofilm Community Shown to Be Dominated by Gammaproteobacteria and Bacteroidetes

    Directory of Open Access Journals (Sweden)

    Jennifer L. Edwards

    2010-10-01

    Full Text Available Polysaccharides are an important source of organic carbon in the marine environment and degradation of the insoluble and globally abundant cellulose is a major component of the marine carbon cycle. Although a number of species of cultured bacteria are known to degrade crystalline cellulose, little is known of the polysaccharide hydrolases expressed by cellulose-degrading microbial communities, particularly in the marine environment. Next generation 454 Pyrosequencing was applied to analyze the microbial community that colonizes and degrades insoluble polysaccharides in situ in the Irish Sea. The bioinformatics tool MG-RAST was used to examine the randomly sampled data for taxonomic markers and functional genes, and showed that the community was dominated by members of the Gammaproteobacteria and Bacteroidetes. Furthermore, the identification of 211 gene sequences matched to a custom-made database comprising the members of nine glycoside hydrolase families revealed an extensive repertoire of functional genes predicted to be involved in cellulose utilization. This demonstrates that the use of an in situ cellulose baiting method yielded a marine microbial metagenome considerably enriched in functional genes involved in polysaccharide degradation. The research reported here is the first designed to specifically address the bacterial communities that colonize and degrade cellulose in the marine environment and to evaluate the glycoside hydrolase (cellulase and chitinase gene repertoire of that community, in the absence of the biases associated with PCR-based molecular techniques.

  8. 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,

  9. 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 ...

  10. Optimized candidal biofilm microtiter assay

    NARCIS (Netherlands)

    Krom, Bastiaan P.; Cohen, Jesse B.; Feser, Gail E. McElhaney; Cihlar, Ronald L.

    Microtiter based candidal biofilm formation is commonly being used. Here we describe the analysis of factors influencing the development of candidal biofilms such as the coating with serum, growth medium and pH. The data reported here show that optimal candidal biofilm formation is obtained when

  11. Biofilm formation on abiotic surfaces

    DEFF Research Database (Denmark)

    Tang, Lone

    2011-01-01

    Bacteria can attach to any surface in contact with water and proliferate into complex communities enclosed in an adhesive matrix, these communities are called biofilms. The matrix makes the biofilm difficult to remove by physical means, and bacteria in biofilm can survive treatment with many...

  12. Biofilms associated with bowel necrosis: A newly recognised ...

    African Journals Online (AJOL)

    All specimens showed varying degrees of bowel necrosis and an organising acute peritoneal reaction. In addition, all showed colonies of Gram-negative bacteria within a mucopolysaccharide matrix. Conclusions. The identification of biofilms in necrotic bowel has raised questions regarding their clinical implications. Further ...

  13. Determination of virulence factors and biofilm formation among isolates of vulvovaginal candidiasis

    Directory of Open Access Journals (Sweden)

    Tapan Majumdar

    2016-01-01

    Full Text Available Context: Under morphogenesis-inducing conditions, Candida spp. begins to undergo yeast-to-hypha switch. This shift from commensal to pathogenic state is dependent on several virulence factors. Aim: To find out whether the isolated Candida spp. were pathogens causing vulvovaginal candidiasis or mere bystanders. Settings and Design: Cross-sectional observational study conducted on 275 symptomatic hospital patients in Tripura between August 2012 and April 2015. Subjects and Methods: Discharge was collected from patients and identified by Grams staining and wet mount test. Culturing was done in Sabouraud dextrose agar followed by speciation. To test for virulence factors, assays for adherence, plasma coagulase, phospholipase, lipase, protease, hemolysin, and biofilm formation were carried out. Statistical Analysis Used: Significance between two groups was compared using one-way analysis of variance along with Tukey test, and Chi-square 2 × 2 contingency table at 95% confidence interval. Results: Fifty-six Candida spp. could be isolated in the study which was used for further virulence tests. One hundred percent of isolates expressed adherence. Among other virulence factors, maximum virulence 25 (45% was shown through protease production. Hemolysin production and biofilm formation were the second most 22 (39% expressed virulence factors. In a comparison of virulence factors between biofilm-forming isolates and planktonic cells, significant difference was seen for plasma coagulase and hemolysin production. Conclusions: All the isolates expressed one or more virulence factors. Adherence was expressed in all isolates but highest number was observed for Candida albicans. Furthermore, C. albicans strain number was highest for protease, hemolysin and coagulase expression and biofilm formation. Candida krusei isolates were the least in number for expressing any of the virulence factors. Significantly higher number of biofilm forming isolates produced

  14. Biofilm Production in Carbapenem Resistant Isolates from Chronic Wound Infections

    Directory of Open Access Journals (Sweden)

    Swarna SR

    2017-02-01

    Full Text Available Biofilms are communities of microorganisms covered with extracellular polymeric substances. Such biofilm phenotype makes the microorganism resistant to antibiotics and plays a role in wound chronicity. This results in prolonged hospital stays in ICU, greater cost, and increased mortality. Methods: Pus swabs (59 were collected from a tertiary care hospital near Chennai were processed and identified using standard procedure followed by antibiotic susceptibility testing and identification of carbapenem resistance by Modified Hodge test as per CLSI guidelines. The biofilm formation was tested using plastic microtiter plate method. Results: Out of 59 pus swabs, 51 yielded growth with 69 isolates and 8 yielded no growth. Among the 69 isolates, 51 were GNB and 18 were GPC. Biofilm detection was noted in 84.31% (43/51 GNB isolates with 0.1% crystal violet whereas 100% (51/51 showed biofilm positive with 0.1% safranin. About 74.50% (38/51 isolates of GNB were carbapenem resistant by screening with disk diffusion method. Only 24% (6/25 of GNB isolates among Enterobacteriaceae were positive by Modified Hodge test method. Conclusion: The result shows the association of biofilm production among carbapenem resistant isolates obtained from chronic wound infections.

  15. Study of biofilm in bacteria from water pipelines.

    Science.gov (United States)

    Mahapatra, Ashoka; Padhi, Nupur; Mahapatra, Dharitri; Bhatt, Mamta; Sahoo, Debasish; Jena, Swetlina; Dash, Debabrata; Chayani, Nirupama

    2015-03-01

    A biofilm is a layer of microorganisms contained in a matrix (slime layer), which forms on surfaces in contact with water. Their presence in drinking water pipe networks can be responsible for a wide range of water quality and operational problems. To identify the bacterial isolates, obtained from water pipelines of kitchens, to evaluate the water quality & to study the biofilm producing capacity of the bacterial isolates from various sources. A prospective study using water samples from aqua guard & pipelines to kitchens of S.C.B Medical College hostels. Standard biochemical procedures for bacterial identification, multiple tube culture & MPN count to evaluate water quality & tissue culture plate (TCP) method for biofilm detection was followed. STATA software version 9.2 from STATA Corporation, College station road, 90 Houston, Texas was used for statistical analysis. One hundred eighty seven isolates were obtained from 45 water samples cultured. The isolates were Acinetobacter spp. (44), Pseudomonas spp.(41), Klebsiella spp.(36) & others . Biofilm was detected in (37) 19.78 % of the isolates (95% CI 30.08% -43.92%) including Acinetobacter spp.-10, Klebsiella spp. - 9, Pseudomonas spp. - 9, & others, majority (34) of which were from kitchen pipelines. Water from pipeline sources was unsatisfactory for consumption as the MPN counts were > 10. Most of the biofilm producers were gram negative bacilli & Pseudomonas & Acinetobacter spp. were strong (4+) biofilm producers.

  16. Alginate production affects Pseudomonas aeruginosa biofilm development and architecture, but is not essential for biofilm formation

    DEFF Research Database (Denmark)

    Stapper, A.P.; Narasimhan, G.; Oman, D.E.

    2004-01-01

    of their biofilm formation using confocal laser scanning microscopy. Biofilm Image Processing (BIP) and Community Statistics (COMSTAT) software programs were used to provide quantitative measurements of the two-dimensional biofilm images. All three strains formed distinguishable biofilm architectures, indicating...

  17. Association between pathogens from tracheal aspirate and oral biofilm of patients on mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Luana Carneiro Diniz SOUZA

    2017-06-01

    Full Text Available Abstract The aim of this study was to detect possible associations between respiratory pathogens from tracheal aspirate and oral biofilm samples in intubated patients in an intensive care unit (ICU, and to identify the most common respiratory pathogens in oral biofilm, particularly in patients that developed ventilator-associated pneumonia (VAP. Two oral biofilm samples were collected from the tongue of intubated patients (at admission and after 48 hours and analyzed by culture with the Antibiotic Sensitivity Test. The results from the tongue biofilm samples were compared with the tracheal secretions samples. A total of 59.37% of patients exhibited the same species of pathogens in their tracheal aspirate and oral biofilm, of which 8 (42.1% developed VAP, 10 (52.63% did not develop pneumonia and one (5.26% had aspiration pneumonia. There was a statistically significant association between presence of microorganisms in the tracheal and mouth samples for the following pathogens: Klebsiella pneumoniae, Candida albicans, Pseudomonas aeruginosa, Enterobacter gergoviae, Streptococcus spp and Serratia marcescens (p < 0.05. Pathogens that are present in tracheal aspirates of intubated patients can be detected in their oral cavity, especially in those who developed VAP or aspiration pneumonia. Thus, the results indicate that an improved oral care in these patients could decrease ICU pneumonia rates.

  18. Association between pathogens from tracheal aspirate and oral biofilm of patients on mechanical ventilation.

    Science.gov (United States)

    Souza, Luana Carneiro Diniz; Mota, Vanise Barros Rodrigues da; Carvalho, Alícia Valéria Dos Santos Zaranza de; Corrêa, Rita da Graça Carvalhal Frazão; Libério, Silvana Amado; Lopes, Fernanda Ferreira

    2017-06-05

    The aim of this study was to detect possible associations between respiratory pathogens from tracheal aspirate and oral biofilm samples in intubated patients in an intensive care unit (ICU), and to identify the most common respiratory pathogens in oral biofilm, particularly in patients that developed ventilator-associated pneumonia (VAP). Two oral biofilm samples were collected from the tongue of intubated patients (at admission and after 48 hours) and analyzed by culture with the Antibiotic Sensitivity Test. The results from the tongue biofilm samples were compared with the tracheal secretions samples. A total of 59.37% of patients exhibited the same species of pathogens in their tracheal aspirate and oral biofilm, of which 8 (42.1%) developed VAP, 10 (52.63%) did not develop pneumonia and one (5.26%) had aspiration pneumonia. There was a statistically significant association between presence of microorganisms in the tracheal and mouth samples for the following pathogens: Klebsiella pneumoniae, Candida albicans, Pseudomonas aeruginosa, Enterobacter gergoviae, Streptococcus spp and Serratia marcescens (p aspirates of intubated patients can be detected in their oral cavity, especially in those who developed VAP or aspiration pneumonia. Thus, the results indicate that an improved oral care in these patients could decrease ICU pneumonia rates.

  19. Silver colloidal nanoparticle stability: influence on Candida biofilms formed on denture acrylic.

    Science.gov (United States)

    Monteiro, Douglas Roberto; Takamiya, Aline Satie; Feresin, Leonardo Perina; Gorup, Luiz Fernando; de Camargo, Emerson Rodrigues; Delbem, Alberto Carlos Botazzo; Henriques, Mariana; Barbosa, Debora Barros

    2014-08-01

    Our aim in this study was to evaluate how the chemical stability of silver nanoparticles (SNs) influences their efficacy against Candida albicans and C. glabrata biofilms. Several parameters of SN stability were tested, namely, temperature (50ºC, 70ºC, and 100ºC), pH (5.0 and 9.0), and time of contact (5 h and 24 h) with biofilms. The control was defined as SNs without temperature treatment, pH 7, and 24 h of contact. These colloidal suspensions at 54 mg/L were used to treat mature Candida biofilms (48 h) formed on acrylic. Their efficacy was determined by total biomass and colony-forming unit quantification. Data were analyzed using analysis of variance and the Bonferroni post hoc test (α = 0.05). The temperature and pH variations of SNs did not affect their efficacy against the viable cells of Candida biofilms (P > 0.05). Moreover, the treatment periods were not decisive in terms of the susceptibility of Candida biofilms to SNs. These findings provide an important advantage of SNs that may be useful in the treatment of Candida-associated denture stomatitis. © 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.

  20. Dental biofilm infections

    DEFF Research Database (Denmark)

    Larsen, Tove; Fiehn, Nils-Erik

    2017-01-01

    and cause gingival inflammation and breakdown of supporting periodontal fibers and bone and ultimately tooth loss, i.e., gingivitis, chronic or aggressive periodontitis, and around dental implants, peri-implantitis. Furthermore, bacteria from the dental biofilm may spread to other parts of the body......-fermenting bacteria causing demineralization of teeth, dental caries, which may further lead to inflammation and necrosis in the pulp and periapical region, i.e., pulpitis and periapical periodontitis. In supra- and subgingival biofilms, predominantly gram-negative, anaerobic proteolytic bacteria will colonize...

  1. Pseudomonas aeruginosa Biofilms

    DEFF Research Database (Denmark)

    Alhede, Maria; Bjarnsholt, Thomas; Givskov, Michael

    2014-01-01

    biofilms, which protect the aggregated, biopolymer-embedded bacteria from the detrimental actions of antibiotic treatments and host immunity. A key component in the protection against innate immunity is rhamnolipid, which is a quorum sensing (QS)-regulated virulence factor. QS is a cell-to-cell signaling...... mechanism used to coordinate expression of virulence and protection of aggregated biofilm cells. Rhamnolipids are known for their ability to cause hemolysis and have been shown to cause lysis of several cellular components of the human immune system, for example, macrophages and polymorphonuclear leukocytes...

  2. 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

  3. Manipulatiaon of Biofilm Microbial Ecology

    Energy Technology Data Exchange (ETDEWEB)

    Burkhalter, R.; Macnaughton, S.J.; Palmer, R.J.; Smith, C.A.; Whitaker, K.W.; White, D.C.; Zinn, M.; kirkegaard, R.

    1998-08-09

    The Biofilm mode of growth provides such significant advantages to the members of the consortium that most organisms in important habitats are found in biofilms. The study of factors that allow manipulation of biofilm microbes in the biofilm growth state requires that reproducible biofilms by generated. The most effective monitoring of biofilm formation, succession and desquamation is with on-line monitoring of microbial biofilms with flowcell for direct observation. The biofilm growth state incorporates a second important factor, the heterogeneity in the distribution in time and space of the component members of the biofilm consortium. This heterogeneity is reflected not only in the cellular distribution but in the metabolic activity within a population of cells. Activity and cellular distribution can be mapped in four dimensions with confocal microscopy, and function can be ascertained by genetically manipulated reporter functions for specific genes or by vital stains. The methodology for understanding the microbial ecology of biofilms is now much more readily available and the capacity to manipulate biofilms is becoming an important feature of biotechnology.

  4. Bacterial biofilm and associated infections

    Directory of Open Access Journals (Sweden)

    Muhsin Jamal

    2018-01-01

    Full Text Available Microscopic entities, microorganisms that drastically affect human health need to be thoroughly investigated. A biofilm is an architectural colony of microorganisms, within a matrix of extracellular polymeric substance that they produce. Biofilm contains microbial cells adherent to one-another and to a static surface (living or non-living. Bacterial biofilms are usually pathogenic in nature and can cause nosocomial infections. The National Institutes of Health (NIH revealed that among all microbial and chronic infections, 65% and 80%, respectively, are associated with biofilm formation. The process of biofilm formation consists of many steps, starting with attachment to a living or non-living surface that will lead to formation of micro-colony, giving rise to three-dimensional structures and ending up, after maturation, with detachment. During formation of biofilm several species of bacteria communicate with one another, employing quorum sensing. In general, bacterial biofilms show resistance against human immune system, as well as against antibiotics. Health related concerns speak loud due to the biofilm potential to cause diseases, utilizing both device-related and non-device-related infections. In summary, the understanding of bacterial biofilm is important to manage and/or to eradicate biofilm-related diseases. The current review is, therefore, an effort to encompass the current concepts in biofilm formation and its implications in human health and disease.

  5. Manipulation of Biofilm Microbial Ecology

    Energy Technology Data Exchange (ETDEWEB)

    White, D.C.; Palmer, R.J., Jr.; Zinn, M.; Smith, C.A.; Burkhalter, R.; Macnaughton, S.J.; Whitaker, K.W.; Kirkegaard, R.D.

    1998-08-15

    The biofilm mode of growth provides such significant advantages to the members of the consortium that most organisms in important habitats are found in biofilms. The study of factors that allow manipulation of biofilm microbes in the biofilm growth state requires that reproducible biofilms be generated. The most effective monitoring of biofilm formation, succession and desaturation is with on-line monitoring of microbial biofilms with flowcell for direct observation. The biofilm growth state incorporates a second important factor, the heterogeneity in distribution in time and space of the component members of the biofilm consortium. This heterogeneity is reflected not only in the cellular distribution but in the metabolic activity within a population of cells. Activity and cellular distribution can be mapped in four dimensions with confocal microscopy, and function can be ascertained by genetically manipulated reporter functions for specific genes or by vital stains. The methodology for understanding the microbial ecology of biofilms is now much more readily available and the capacity to manipulate biofilms is becoming an important feature of biotechnology.

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

    Directory of Open Access Journals (Sweden)

    Read Pukkila-Worley

    2011-06-01

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

  7. Biofilm in endodontics: A review

    Science.gov (United States)

    Jhajharia, Kapil; Parolia, Abhishek; Shetty, K Vikram; Mehta, Lata Kiran

    2015-01-01

    Endodontic disease is a biofilm-mediated infection, and primary aim in the management of endodontic disease is the elimination of bacterial biofilm from the root canal system. The most common endodontic infection is caused by the surface-associated growth of microorganisms. It is important to apply the biofilm concept to endodontic microbiology to understand the pathogenic potential of the root canal microbiota as well as to form the basis for new approaches for disinfection. It is foremost to understand how the biofilm formed by root canal bacteria resists endodontic treatment measures. Bacterial etiology has been confirmed for common oral diseases such as caries and periodontal and endodontic infections. Bacteria causing these diseases are organized in biofilm structures, which are complex microbial communities composed of a great variety of bacteria with different ecological requirements and pathogenic potential. The biofilm community not only gives bacteria effective protection against the host's defense system but also makes them more resistant to a variety of disinfecting agents used as oral hygiene products or in the treatment of infections. Successful treatment of these diseases depends on biofilm removal as well as effective killing of biofilm bacteria. So, the fundamental to maintain oral health and prevent dental caries, gingivitis, and periodontitis is to control the oral biofilms. From these aspects, the formation of biofilms carries particular clinical significance because not only host defense mechanisms but also therapeutic efforts including chemical and mechanical antimicrobial treatment measures have the most difficult task of dealing with organisms that are gathered in a biofilm. The aim of this article was to review the mechanisms of biofilms’ formation, their roles in pulpal and periapical pathosis, the different types of biofilms, the factors influencing biofilm formation, the mechanisms of their antimicrobial resistance, techniques to

  8. Biofilm roughness determines Cryptosporidium parvum retention in environmental biofilms.

    Science.gov (United States)

    DiCesare, E A Wolyniak; Hargreaves, B R; Jellison, K L

    2012-06-01

    The genus Cryptosporidium is a group of waterborne protozoan parasites that have been implicated in significant outbreaks of gastrointestinal infections throughout the world. Biofilms trap these pathogens and can contaminate water supplies through subsequent release. Biofilm microbial assemblages were collected seasonally from three streams in eastern Pennsylvania and used to grow biofilms in laboratory microcosms. Daily oocyst counts in the influx and efflux flow allowed the calculation of daily oocyst retention in the biofilm. Following the removal of oocysts from the influx water, oocyst attachment to the biofilm declined to an equilibrium state within 5 days that was sustained for at least 25 days. Varying the oocyst loading rate for the system showed that biofilm retention could be saturated, suggesting that discrete binding sites determined the maximum number of oocysts retained. Oocyst retention varied seasonally but was consistent across all three sites; however, seasonal oocyst retention was not consistent across years at the same site. No correlation between oocyst attachment and any measured water quality parameter was found. However, oocyst retention was strongly correlated with biofilm surface roughness and roughness varied among seasons and across years. We hypothesize that biofilm roughness and oocyst retention are dependent on environmentally driven changes in the biofilm community rather than directly on water quality conditions. It is important to understand oocyst transport dynamics to reduce risks of human infection. Better understanding of factors controlling biofilm retention of oocysts should improve our understanding of oocyst transport at different scales.

  9. Anti-Biofilm Activity of a Long-Chain Fatty Aldehyde from Antarctic Pseudoalteromonas haloplanktis TAC125 against Staphylococcus epidermidis Biofilm.

    Science.gov (United States)

    Casillo, Angela; Papa, Rosanna; Ricciardelli, Annarita; Sannino, Filomena; Ziaco, Marcello; Tilotta, Marco; Selan, Laura; Marino, Gennaro; Corsaro, Maria M; Tutino, Maria L; Artini, Marco; Parrilli, Ermenegilda

    2017-01-01

    Staphylococcus epidermidis is a harmless human skin colonizer responsible for ~20% of orthopedic device-related infections due to its capability to form biofilm. Nowadays there is an interest in the development of anti-biofilm molecules. Marine bacteria represent a still underexploited source of biodiversity able to synthesize a broad range of bioactive compounds, including anti-biofilm molecules. Previous results have demonstrated that the culture supernatant of Antarctic marine bacterium Pseudoalteromonas haloplanktis TAC125 impairs the formation of S. epidermidis biofilm. Further, evidence supports the hydrophobic nature of the active molecule, which has been suggested to act as a signal molecule. In this paper we describe an efficient activity-guided purification protocol which allowed us to purify this anti-biofilm molecule and structurally characterize it by NMR and mass spectrometry analyses. Our results demonstrate that the anti-biofilm molecule is pentadecanal, a long-chain fatty aldehyde, whose anti- S. epidermidis biofilm activity has been assessed using both static and dynamic biofilm assays. The specificity of its action on S. epidermidis biofilm has been demonstrated by testing chemical analogs of pentadecanal differing either in the length of the aliphatic chain or in their functional group properties. Further, indications of the mode of action of pentadecanal have been collected by studying the bioluminescence of a Vibrio harveyi reporter strain for the detection of autoinducer AI-2 like activities. The data collected suggest that pentadecanal acts as an AI-2 signal. Moreover, the aldehyde metabolic role and synthesis in the Antarctic source strain has been investigated. To the best of our knowledge, this is the first report on the identification of an anti-biofilm molecule form from cold-adapted bacteria and on the action of a long-chain fatty aldehyde acting as an anti-biofilm molecule against S. epidermidis .

  10. PATHOGENICITY OF BIOFILM BACTERIA

    Science.gov (United States)

    There is a paucity of information concerning any link between the microorganisms commonly found in biofilms of drinking water systems and their impacts on human health. For bacteria, culture-based techniques detect only a limited number of the total microorganisms associated wit...

  11. [Biofilms in otolaryngology].

    Science.gov (United States)

    Mena Viveros, Nicolás

    2014-01-01

    According to the National Institute of Health of the USA, «more than 60% of all microbial infections are caused by biofilms».'This can surprise us, but it is enough to consider that common infections like those of the genito-urinary tract, infections produced by catheters, middle ear infections in children, the formation of dental plaque and gingivitis are caused by biofilms, for this statement to seem more realistic. At present this is one of the subjects of great interest within medicine, particularly in otolaryngology. Bacteria have traditionally been considered to be in a free state without evident organization, partly perhaps by the ease of studying them in this form. Nevertheless, the reality is that, in nature, the great majority of these germs form complex colonies adhered to surfaces, colonies that have received the name of biofilms. These biofilms are more common than previously thought and almost all of the people have been in contact with them in the form of infections in the teeth or humid, slippery areas. New treatments that can eradicate them are currently being investigated. Copyright © 2012 Elsevier España, S.L. All rights reserved.

  12. Bacterial and fungal biofilm formation on contact lenses and their susceptibility to lens care solutions

    Directory of Open Access Journals (Sweden)

    Siddharth Kackar

    2017-01-01

    Full Text Available Background: Microbial biofilm formation on contact lenses and lens storage cases may be a risk factor for contact lens-associated corneal infections. Various types of contact lens care solutions are used to reduce microbial growths on lenses. Objectives: The present study aimed at comparing the growths of biofilms on the different contact lenses and lens cases. The study also aimed at determining the effect of lens care solutions and bacteriophage on these biofilms. Materials and Methods: One type of hard lens and two types of soft lenses were used for the study. The organisms used were Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 60193 and Escherichia coli ATCC 25922. Biofilm production was performed by modified O'Toole and Kolter method and effect of lens cleaning solutions and a crude coliphage on biofilms was also studied. Results were visualised using scanning electron microscopy and quantitated by colony counting method and spectrophotometric measurement of optical density (OD. Statistical analysis was done by SPSS 11.5, Kruskal–Wallis test and Chi-square test. Results: Soft lens cleaning solutions had a significant inhibitory effect (P = 0.020 on biofilm formation on soft lenses and also lens cases (P < 0.001. Soft lens cleaning solution 2 was more efficient than solution 1. However, no such inhibitory effect was observed with regard to hard lens cleaning solution, but for a significant reduction in the OD values (P < 0.001. There was no significant inhibitory effect by bacteriophages. Conclusion: This study showed the importance of selecting the appropriate lens cleaning solution to prevent biofilm production on contact lenses.

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

    Directory of Open Access Journals (Sweden)

    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

  14. May one-stage exchange for Candida albicans peri-prosthetic infection be successful?

    Science.gov (United States)

    Jenny, J-Y; Goukodadja, O; Boeri, C; Gaudias, J

    2016-02-01

    Fungal infection of a total joint arthroplasty has a low incidence but is generally considered as more difficult to cure than bacterial infection. As for bacterial infection, two-stage exchange is considered as the gold standard of treatment. We report two cases of one-stage total joint exchange for fungal peri-prosthetic infection with Candida albicans, where the responsible pathogens was only identified on intraoperative samples. This situation can be considered as a one-stage exchange for fungal peri-prosthetic infection without preoperative identification of the responsible organism, which is considered as having a poor prognosis. Both cases were free of infection after two years. One-stage revision has several potential advantages over two-stage revision, including shorter hospital stay and rehabilitation, no interim period with significant functional impairment, shorter antibiotic treatment, better functional outcome and probably lower costs. We suggest that one-stage revision for C. albicans peri-prosthetic infection may be successful even without preoperative fungal identification. Level IV-Historical cases. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  15. A functional portrait of Med7 and the mediator complex in Candida albicans.

    Science.gov (United States)

    Tebbji, Faiza; Chen, Yaolin; Richard Albert, Julien; Gunsalus, Kearney T W; Kumamoto, Carol A; Nantel, André; Sellam, Adnane; Whiteway, Malcolm

    2014-11-01

    Mediator is a multi-subunit protein complex that regulates gene expression in eukaryotes by integrating physiological and developmental signals and transmitting them to the general RNA polymerase II machinery. We examined, in the fungal pathogen Candida albicans, a set of conditional alleles of genes encoding Mediator subunits of the head, middle, and tail modules that were found to be essential in the related ascomycete Saccharomyces cerevisiae. Intriguingly, while the Med4, 8, 10, 11, 14, 17, 21 and 22 subunits were essential in both fungi, the structurally highly conserved Med7 subunit was apparently non-essential in C. albicans. While loss of CaMed7 did not lead to loss of viability under normal growth conditions, it dramatically influenced the pathogen's ability to grow in different carbon sources, to form hyphae and biofilms, and to colonize the gastrointestinal tracts of mice. We used epitope tagging and location profiling of the Med7 subunit to examine the distribution of the DNA sites bound by Mediator during growth in either the yeast or the hyphal form, two distinct morphologies characterized by different transcription profiles. We observed a core set of 200 genes bound by Med7 under both conditions; this core set is expanded moderately during yeast growth, but is expanded considerably during hyphal growth, supporting the idea that Mediator binding correlates with changes in transcriptional activity and that this binding is condition specific. Med7 bound not only in the promoter regions of active genes but also within coding regions and at the 3' ends of genes. By combining genome-wide location profiling, expression analyses and phenotyping, we have identified different Med7p-influenced regulons including genes related to glycolysis and the Filamentous Growth Regulator family. In the absence of Med7, the ribosomal regulon is de-repressed, suggesting Med7 is involved in central aspects of growth control.

  16. 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.

  17. 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

  18. 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.

  19. 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...

  20. 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,...

  1. 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.

  2. New Technologies for Studying Biofilms

    Science.gov (United States)

    FRANKLIN, MICHAEL J.; CHANG, CONNIE; AKIYAMA, TATSUYA; BOTHNER, BRIAN

    2016-01-01

    Bacteria have traditionally been studied as single-cell organisms. In laboratory settings, aerobic bacteria are usually cultured in aerated flasks, where the cells are considered essentially homogenous. However, in many natural environments, bacteria and other microorganisms grow in mixed communities, often associated with surfaces. Biofilms are comprised of surface-associated microorganisms, their extracellular matrix material, and environmental chemicals that have adsorbed to the bacteria or their matrix material. While this definition of a biofilm is fairly simple, biofilms are complex and dynamic. Our understanding of the activities of individual biofilm cells and whole biofilm systems has developed rapidly, due in part to advances in molecular, analytical, and imaging tools and the miniaturization of tools designed to characterize biofilms at the enzyme level, cellular level, and systems level. PMID:26350329

  3. Silver against Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Kirketerp-Møller, K.; Kristiansen, S.

    2007-01-01

    bacteria in both the planktonic and biofilm modes of growth. The action of silver on mature in vitro biofilms of Pseudomonas aeruginosa, a primary pathogen of chronic infected wounds, was investigated. The results show that silver is very effective against mature biofilms of P. aeruginosa......, but that the silver concentration is important. A concentration of 5-10 ig/mL silver sulfadiazine eradicated the biofilm whereas a lower concentration (1 ig/mL) had no effect. The bactericidal concentration of silver required to eradicate the bacterial biofilm was 10-100 times higher than that used to eradicate...... planktonic bacteria. These observations strongly indicate that the concentration of silver in currently available wound dressings is much too low for treatment of chronic biofilm wounds. It is suggested that clinicians and manufacturers of the said wound dressings consider whether they are treating wounds...

  4. Acyclic N-halamine-immobilized polyurethane: Preparation and antimicrobial and biofilm-controlling functions

    Science.gov (United States)

    Luo, Jie; Porteous, Nuala; Lin, Jiajin; Sun, Yuyu

    2015-01-01

    Hydroxyl groups were introduced onto polyurethane surfaces through 1,6-hexamethylene diisocyanate activation, followed by diethanolamine hydroxylation. Polymethacrylamide was covalently attached to the hydroxylated polyurethane through surface grafting polymerization of methacrylamide using cerium (IV) ammonium nitrate as an initiator. After bleach treatment, the amide groups of the covalently bound polymethacrylamide chains were transformed into N-halamines. The new N-halamine-immobilized polyurethane provided a total sacrifice of 107–108 colony forming units per milliliter of Staphylococcus aureus (Gram-positive bacteria), Escherichia coli (Gram-negative bacteria), and Candida albicans (fungi) within 10 min and successfully prevented bacterial and fungal biofilm formation. The antimicrobial and biofilm-controlling effects were both durable and rechargeable, pointing to great potentials of the new acyclic N-halamine-immobilized polyurethane for a broad range of related applications. PMID:26089593

  5. Extracellular DNA Contributes to Dental Biofilm Stability

    DEFF Research Database (Denmark)

    Schlafer, Sebastian; Meyer, Rikke Louise; Dige, Irene

    2017-01-01

    dental biofilms. This study aimed to determine whether eDNA was part of the matrix in biofilms grown in situ in the absence of sucrose and whether treatment with DNase dispersed biofilms grown for 2.5, 5, 7.5, 16.5, or 24 h. Three hundred biofilms from 10 study participants were collected and treated...... the amount of biofilm in very early stages of growth (up to 7.5 h), but the treatment effect decreased with increasing biofilm age. This study proves the involvement of eDNA in dental biofilm formation and its importance for biofilm stability in the earliest stages. Further research is required to uncover...

  6. Activation of the Cph1-dependent MAP kinase signaling pathway induces white-opaque switching in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Bernardo Ramírez-Zavala

    Full Text Available Depending on the environmental conditions, the pathogenic yeast Candida albicans can undergo different developmental programs, which are controlled by dedicated transcription factors and upstream signaling pathways. C. albicans strains that are homozygous at the mating type locus can switch from the normal yeast form (white to an elongated cell type (opaque, which is the mating-competent form of this fungus. Both white and opaque cells use the Ste11-Hst7-Cek1/Cek2 MAP kinase signaling pathway to react to the presence of mating pheromone. However, while opaque cells employ the transcription factor Cph1 to induce the mating response, white cells recruit a different downstream transcription factor, Tec1, to promote the formation of a biofilm that facilitates mating of opaque cells in the population. The switch from the white to the opaque cell form is itself induced by environmental signals that result in the upregulation of the transcription factor Wor1, the master regulator of white-opaque switching. To get insight into the upstream signaling pathways controlling the switch, we expressed all C. albicans protein kinases from a tetracycline-inducible promoter in a switching-competent strain. Screening of this library of strains showed that a hyperactive form of Ste11 lacking its N-terminal domain (Ste11(ΔN467 efficiently stimulated white cells to switch to the opaque phase, a behavior that did not occur in response to pheromone. Ste11(ΔN467-induced switching specifically required the downstream MAP kinase Cek1 and its target transcription factor Cph1, but not Cek2 and Tec1, and forced expression of Cph1 also promoted white-opaque switching in a Wor1-dependent manner. Therefore, depending on the activation mechanism, components of the pheromone-responsive MAP kinase pathway can be reconnected to stimulate an alternative developmental program, switching of white cells to the mating-competent opaque phase.

  7. Biofilm and Dental Biomaterials

    Directory of Open Access Journals (Sweden)

    Marit Øilo

    2015-05-01

    Full Text Available All treatment involving the use of biomaterials in the body can affect the host in positive or negative ways. The microbiological environment in the oral cavity is affected by the composition and shape of the biomaterials used for oral restorations. This may impair the patients’ oral health and sometimes their general health as well. Many factors determine the composition of the microbiota and the formation of biofilm in relation to biomaterials such as, surface roughness, surface energy and chemical composition, This paper aims to give an overview of the scientific literature regarding the association between the chemical, mechanical and physical properties of dental biomaterials and oral biofilm formation, with emphasis on current research and future perspectives.

  8. Biofilms promote altruism.

    Science.gov (United States)

    Kreft, Jan-Ulrich

    2004-08-01

    The origin of altruism is a fundamental problem in evolution, and the maintenance of biodiversity is a fundamental problem in ecology. These two problems combine with the fundamental microbiological question of whether it is always advantageous for a unicellular organism to grow as fast as possible. The common basis for these three themes is a trade-off between growth rate and growth yield, which in turn is based on irreversible thermodynamics. The trade-off creates an evolutionary alternative between two strategies: high growth yield at low growth rate versus high growth rate at low growth yield. High growth yield at low growth rate is a case of an altruistic strategy because it increases the fitness of the group by using resources economically at the cost of decreased fitness, or growth rate, of the individual. The group-beneficial behaviour is advantageous in the long term, whereas the high growth rate strategy is advantageous in the short term. Coexistence of species requires differences between their niches, and niche space is typically divided into four 'axes' (time, space, resources, predators). This neglects survival strategies based on cooperation, which extend the possibilities of coexistence, arguing for the inclusion of cooperation as the fifth 'axis'. Here, individual-based model simulations show that spatial structure, as in, for example, biofilms, is necessary for the origin and maintenance of this 'primitive' altruistic strategy and that the common belief that growth rate but not yield decides the outcome of competition is based on chemostat models and experiments. This evolutionary perspective on life in biofilms can explain long-known biofilm characteristics, such as the structural organization into microcolonies, the often-observed lack of mixing among microcolonies, and the shedding of single cells, as promoting the origin and maintenance of the altruistic strategy. Whereas biofilms enrich altruists, enrichment cultures, microbiology's paradigm

  9. [Bacterial biofilms and infection].

    Science.gov (United States)

    Lasa, I; Del Pozo, J L; Penadés, J R; Leiva, J

    2005-01-01

    In developed countries we tend to think of heart disease and the numerous forms of cancer as the main causes of mortality, but on a global scale infectious diseases come close, or may even be ahead: 14.9 million deaths in 2002 compared to cardiovascular diseases (16.9 million deaths) and cancer (7.1 million deaths) (WHO report 2004). The infectious agents responsible for human mortality have evolved as medical techniques and hygienic measures have changed. Modern-day acute infectious diseases caused by specialized bacterial pathogens such as diphtheria, tetanus, cholera, plague, which represented the main causes of death at the beginning of XX century, have been effectively controlled with antibiotics and vaccines. In their place, more than half of the infectious diseases that affect mildly immunocompromised patients involve bacterial species that are commensal with the human body; these can produce chronic infections, are resistant to antimicrobial agents and there is no effective vaccine against them. Examples of these infections are the otitis media, native valve endocarditis, chronic urinary infections, bacterial prostatitis, osteomyelitis and all the infections related to medical devices. Direct analysis of the surface of medical devices or of tissues that have been foci of chronic infections shows the presence of large numbers of bacteria surrounded by an exopolysaccharide matrix, which has been named the "biofilm". Inside the biofilm, bacteria grow protected from the action of the antibodies, phagocytic cells and antimicrobial treatments. In this article, we describe the role of bacterial biofilms in human persistent infections.

  10. The usefulness of DNA sequencing after extraction by Whatman FTA filter matrix technology and phenotypic tests for differentiation of Candida albicans and Candida dubliniensis.

    Science.gov (United States)

    Kiraz, Nuri; Oz, Yasemin; Aslan, Huseyin; Muslumanoglu, Hamza

    2014-02-01

    Since C. dubliniensis is similar to C. albicans phenotypically, it can be misidentified as C. albicans. We aimed to investigate the prevalence of C. dubliniensis among isolates previously identified as C. albicans in our stocks and to compare the phenotypic methods and DNA sequencing of D1/D2 region on the ribosomal large subunit (rLSU) gene. A total of 850 isolates included in this study. Phenotypic identification was performed based on germ tube formation, chlamydospore production, colony colors on chromogenic agar, inability of growth at 45 °C and growth on hypertonic Sabouraud dextrose agar. Eighty isolates compatible with C. dubliniensis by at least one phenotypic test were included in the sequence analysis. Nested PCR amplification of D1/D2 region of the rLSU gene was performed after the fungal DNA extraction by Whatman FTA filter paper technology. The sequencing analysis of PCR products carried out by an automated capillary gel electrophoresis device. The rate of C. dubliniensis was 2.35 % (n = 20) among isolates previously described as C. albicans. Consequently, none of the phenotypic tests provided satisfactory performance alone in our study, and molecular methods required special equipment and high cost. Thus, at least two phenotypic methods can be used for identification of C. dubliniensis, and molecular methods can be used for confirmation.

  11. Biofilm architecture in a novel pressurized biofilm reactor.

    Science.gov (United States)

    Jiang, Wei; Xia, Siqing; Duan, Liang; Hermanowicz, Slawomir W

    2015-01-01

    A novel pure-oxygen pressurized biofilm reactor was operated at different organic loading, mechanical shear and hydrodynamic conditions to understand the relationships between biofilm architecture and its operation. The ultimate goal was to improve the performance of the biofilm reactor. The biofilm was labeled with seven stains and observed with confocal laser scanning microscopy. Unusual biofilm architecture of a ribbon embedded between two surfaces with very few points of attachment was observed. As organic loading increased, the biofilm morphology changed from a moderately rough layer into a locally smoother biomass with significant bulging protuberances, although the chemical oxygen demand (COD) removal efficiency remained unchanged at about 75%. At higher organic loadings, biofilms contained a larger fraction of active cells distributed uniformly within a proteinaceous matrix with decreasing polysaccharide content. Higher hydrodynamic shear in combination with high organic loading resulted in the collapse of biofilm structure and a substantial decrease in reactor performance (a COD removal of 16%). Moreover, the important role of proteins for the spatial distribution of active cells was demonstrated quantitatively.

  12. Microbiology and performance of a methanogenic biofilm reactor during the start-up period.

    Science.gov (United States)

    Cresson, R; Dabert, P; Bernet, N

    2009-03-01

    To understand the interactions between anaerobic biofilm development and process performances during the start-up period of methanogenic biofilm reactor. Two methanogenic inverse turbulent bed reactors have been started and monitored for 81 days. Biofilm development (adhesion, growth, population dynamic) and characteristics (biodiversity, structure) were investigated using molecular tools (PCR-SSCP, FISH-CSLM). Identification of the dominant populations, in relation to process performances and to the present knowledge of their metabolic activities, was used to propose a global scheme of the degradation routes involved. The inoculum, which determines the microbial species present in the biofilm influences bioreactor performances during the start-up period. FISH observations revealed a homogeneous distribution of the Archaea and bacterial populations inside the biofilm. This study points out the link between biodiversity, functional stability and methanogenic process performances during start-up of anaerobic biofilm reactor. It shows that inoculum and substrate composition greatly influence biodiversity, physiology and structure of the biofilm. The combination of molecular techniques associated to a biochemical engineering approach is useful to get relevant information on the microbiology of a methanogenic growing biofilm, in relation with the start-up of the process.

  13. An ecological perspective of Listeria monocytogenes biofilms in food processing facilities.

    Science.gov (United States)

    Valderrama, Wladir B; Cutter, Catherine N

    2013-01-01

    Listeria monocytogenes can enter the food chain at virtually any point. However, food processing environments seem to be of particular importance. From an ecological point of view, food processing facilities are microbial habitats that are constantly disturbed by cleaning and sanitizing procedures. Although L. monocytogenes is considered ubiquitous in nature, it is important to recognize that not all L. monocytogenes strains appear to be equally distributed; the distribution of the organism seems to be related to certain habitats. Currently, no direct evidence exists that L. monocytogenes-associated biofilms have played a role in food contamination or foodborne outbreaks, likely because biofilm isolation and identification are not part of an outbreak investigation, or the definition of biofilm is unclear. Because L. monocytogenes is known to colonize surfaces, we suggest that contamination patterns may be studied in the context of how biofilm formation is influenced by the environment within food processing facilities. In this review, direct and indirect epidemiological and phenotypic evidence of lineage-related biofilm formation capacity to specific ecological niches will be discussed. A critical view on the development of the biofilm concept, focused on the practical implications, strengths, and weaknesses of the current definitions also is discussed. The idea that biofilm formation may be an alternative surrogate for microbial fitness is proposed. Furthermore, current research on the influence of environmental factors on biofilm formation is discussed.

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

    Directory of Open Access Journals (Sweden)

    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

  15. Staphylococcus aureus biofilms: recent developments in biofilm dispersal.

    Science.gov (United States)

    Lister, Jessica L; Horswill, Alexander R

    2014-01-01

    Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and represents a significant burden on the healthcare system. S. aureus attachment to medical implants and host tissue, and the establishment of a mature biofilm, play an important role in the persistence of chronic infections. The formation of a biofilm, and encasement of cells in a polymer-based matrix, decreases the susceptibility to antimicrobials and immune defenses, making these infections difficult to eradicate. During infection, dispersal of cells from the biofilm can result in spread to secondary sites and worsening of the infection. In this review, we discuss the current understanding of the pathways behind biofilm dispersal in S. aureus, with a focus on enzymatic and newly described broad-spectrum dispersal mechanisms. Additionally, we explore potential applications of dispersal in the treatment of biofilm-mediated infections.

  16. Long-term efficacy of denture cleansers in preventing Candida spp. biofilm recolonization on liner surface.

    Science.gov (United States)

    Vieira, Ana Paula Coelho; Senna, Plínio Mendes; Silva, Wander José da; Del Bel Cury, Altair Antoninha

    2010-01-01

    This study evaluated the long-term efficacy of denture cleansers against Candida spp. biofilm recolonization on liner surface. Specimens were fabricated of a poly(methyl methacrylate)-based denture liner and had their surface roughness evaluated at baseline and after cleansing treatments. C. albicans or C. glabrata biofilms were formed on liner surface for 48 h, and then the specimens were randomly assigned to one of cleaning treatments: two alkaline peroxides (soaking for 3 or 15 min), 0.5% sodium hypochlorite (10 min) or distilled water (control; 15 min). After the treatments, the specimens were sonicated to disrupt the biofilm, and residual cells were counted (cell/mL). Long-term effectiveness of the cleaning processes was determined by submitting a set of cleaned specimens to biofilm growth conditions for 48 h followed by estimation of cell counts. The topography of specimens after cleaning treatments was analyzed by SEM. Data were analyzed by ANOVA and Tukey's test (α; = 0.05). Results of cell count estimation showed significant differences in cleanliness among the treatments (p 0.05) was observed among the Candida species regarding the recolonization condition. Alkaline denture cleansers showed similar cleaning performance and both differed from the control (p recolonization.

  17. The innovation of cryo-SEM freeze-fracturing methodology demonstrated on high pressure frozen biofilm.

    Science.gov (United States)

    Hrubanova, Kamila; Nebesarova, Jana; Ruzicka, Filip; Krzyzanek, Vladislav

    2018-04-22

    In this study we present an innovative method for the preparation of fully hydrated samples of microbial biofilms of cultures Staphylococcus epidermidis, Candida parapsilosis and Candida albicans. Cryo-scanning electron microscopy (cryo-SEM) and high-pressure freezing (HPF) rank among cutting edge techniques in the electron microscopy of hydrated samples such as biofilms. However, the combination of these techniques is not always easily applicable. Therefore, we present a method of combining high-pressure freezing using EM PACT2 (Leica Microsystems), which fixes hydrated samples on small sapphire discs, with a high resolution SEM equipped with the widely used cryo-preparation system ALTO 2500 (Gatan). Using a holder developed in house, a freeze-fracturing technique was applied to image and investigate microbial cultures cultivated on the sapphire discs. In our experiments, we focused on the ultrastructure of the extracellular matrix produced during cultivation and the relationships among microbial cells in the biofilm. The main goal of our investigations was the detailed visualization of areas of the biofilm where the microbial cells adhere to the substrate/surface. We show the feasibility of this technique, which is clearly demonstrated in experiments with various freeze-etching times. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. On the chemical identification and visualization of uranium species in biofilms and Euglena mutabilis cells; Zur chemischen Identifizierung und Visualisierung von Uran-Spezies in Biofilmen und Euglena mutabilis Zellen

    Energy Technology Data Exchange (ETDEWEB)

    Brockmann, Sina

    2013-11-14

    For risk assessment of anthropogenic uranium contaminations in the environment a detailed knowledge of the migration and immobilization behavior is required to prevent health hazards for humans and animals caused by an uncontrolled discharge of uranium. Hence, comprehensive studies on the interactions of uranium with the environment are required. Besides the influences of the geological materials, there is a huge effect of the biosphere, especially the interactions with microorganisms and biofilms, on the properties of uranium in the environment. The aim of this study was to investigate and to describe naturally occurring biofilms from real uranium contaminated areas and their influence on the uranium migration. The investigations in this study on the localization and the speciation of the uranium in the biosystems were primarily done with a coupled system of laser scanning microscopy (CLSM) and laser induced fluorescence spectroscopy (LIFS). Natural biofilms collected from two uranium contaminated acid mine drainage (AMD) environments, the former uranium mine in Koenigstein (Saxony, Germany) and the former Gessenheap near Ronneburg (Thuringia,Germany), were investigated in this study. The chosen samples represent typical biofilm communities living in AMD water and are exemplary for potentially occurring scenarios of contaminated mining water both in the underground and on the surface. The investigation on the interactions between uranium and Euglena mutabilis, which is a typical unicellular microorganism that can be found in acidic, uranium and other heavy metal containing waters, was another important part of this study. Bioaccumulation experiments of uranium on living Euglena mutabilis cells depending on the pH (pH 3 - 6) and on the background media in sodium perchlorate (9 g/l) or sodium sulfate (3.48 g/l) solution containing 0.01 mM uranium show an effective immobilization of uranium. At the acidic pH-values (pH 3 - 4) over 90 % of the added uranium was

  19. 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.

  20. Antibiotic treatment of biofilm infections

    DEFF Research Database (Denmark)

    Ciofu, Oana; Rojo-Molinero, Estrella; Macià, María D.

    2017-01-01

    Bacterial biofilms are associated with a wide range of infections, from those related to exogenous devices, such as catheters or prosthetic joints, to chronic tissue infections such as those occurring in the lungs of cystic fibrosis patients. Biofilms are recalcitrant to antibiotic treatment due ...

  1. Experimental evolution in biofilm populations

    Science.gov (United States)

    Steenackers, Hans P.; Parijs, Ilse; Foster, Kevin R.; Vanderleyden, Jozef

    2016-01-01

    Biofilms are a major form of microbial life in which cells form dense surface associated communities that can persist for many generations. The long-life of biofilm communities means that they can be strongly shaped by evolutionary processes. Here, we review the experimental study of evolution in biofilm communities. We first provide an overview of the different experimental models used to study biofilm evolution and their associated advantages and disadvantages. We then illustrate the vast amount of diversification observed during biofilm evolution, and we discuss (i) potential ecological and evolutionary processes behind the observed diversification, (ii) recent insights into the genetics of adaptive diversification, (iii) the striking degree of parallelism between evolution experiments and real-life biofilms and (iv) potential consequences of diversification. In the second part, we discuss the insights provided by evolution experiments in how biofilm growth and structure can promote cooperative phenotypes. Overall, our analysis points to an important role of biofilm diversification and cooperation in bacterial survival and productivity. Deeper understanding of both processes is of key importance to design improved antimicrobial strategies and diagnostic techniques. PMID:26895713

  2. Microalgal biofilms for wastewater treatment

    NARCIS (Netherlands)

    Boelee, N.C.

    2013-01-01

    The objective of this thesis was to explore the possibilities of using microalgal biofilms for the treatment of municipal wastewater, with a focus on the post-treatment of municipal wastewater effluent. The potential of microalgal biofilms for wastewater treatment was first investigated using a

  3. Microbial ecology of phototrophic biofilms

    NARCIS (Netherlands)

    Roeselers, G.

    2007-01-01

    Biofilms are layered structures of microbial cells and an extracellular matrix of polymeric substances, associated with surfaces and interfaces. Biofilms trap nutrients for growth of the enclosed microbial community and help prevent detachment of cells from surfaces in flowing systems. Phototrophic

  4. Bacterial Biofilms in Jones Tubes.

    Science.gov (United States)

    Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

    To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

  5. Interaction of Nanoparticles with Biofilms

    Science.gov (United States)

    In this work we have studied the interaction and adsorption of engineered nanoparticles such as TiO2, ZnO, CeO2 , and carbon nanotubes with biofilms. Biofilm is an extracellular polymeric substance coating comprised of living material and it is an aggregation of bacteria, algae, ...

  6. 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

  7. Biofilm models of polymicrobial infection.

    Science.gov (United States)

    Gabrilska, Rebecca A; Rumbaugh, Kendra P

    2015-01-01

    Interactions between microbes are complex and play an important role in the pathogenesis of infections. These interactions can range from fierce competition for nutrients and niches to highly evolved cooperative mechanisms between different species that support their mutual growth. An increasing appreciation for these interactions, and desire to uncover the mechanisms that govern them, has resulted in a shift from monomicrobial to polymicrobial biofilm studies in different disease models. Here we provide an overview of biofilm models used to study select polymicrobial infections and highlight the impact that the interactions between microbes within these biofilms have on disease progression. Notable recent advances in the development of polymicrobial biofilm-associated infection models and challenges facing the study of polymicrobial biofilms are addressed.

  8. Antibiotic resistance of bacterial biofilms

    DEFF Research Database (Denmark)

    Hoiby, N.; Bjarnsholt, T.; Givskov, M.

    2010-01-01

    A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis...... and other components of the body's defence system. The persistence of, for example, staphylococcal infections related to foreign bodies is due to biofilm formation. Likewise, chronic Pseudomonas aeruginosa lung infection in cystic fibrosis patients is caused by biofilm-growing mucoid strains....... Characteristically, gradients of nutrients and oxygen exist from the top to the bottom of biofilms and these gradients are associated with decreased bacterial metabolic activity and increased doubling times of the bacterial cells; it is these more or less dormant cells that are responsible for some of the tolerance...

  9. Antibiotic tolerance and microbial biofilms

    DEFF Research Database (Denmark)

    Folkesson, Anders

    Increased tolerance to antimicrobial agents is thought to be an important feature of microbes growing in biofilms. We study the dynamics of antibiotic action within hydrodynamic flow chamber biofilms of Escherichia coli and Pseudomonas aeruginosa using isogenic mutants and fluorescent gene...... expression reporters and we address the question of how biofilm organization affects antibiotic susceptibility. The dynamics of microbial killing is monitored by viable count determination, and confocal laser microscopy. Our work shows that the apparent increased antibiotic tolerance is due to the formation...... of antibiotic tolerant subpopulations within the biofilm. The formation of these subpopulations is highly variable and dependent on the antibiotic used, the biofilm structural organization and the induction of specific tolerance mechanisms....

  10. Bioactivity Assessment of Indian Origin-Mangrove Actinobacteria against Candida albicans.

    Science.gov (United States)

    Pavan Kumar, J G S; Gomathi, Ajitha; Gothandam, K M; Vasconcelos, Vitor

    2018-02-12

    Actinobacteria is found to have a potent metabolic activity against pathogens. The present study reveals the assessment of potent antifungal secondary metabolites from actinobacteria isolated from Indian marine mangrove sediments. The samples were collected from the coastal regions of Muthupet, Andaman and the Nicobar Islands. Identification was carried out using 16S rRNA analysis and biosynthetic genes (Polyketide synthase type I/II and Non-ribosomal peptide synthase) were screened. Actinobacteria were assayed for their antifungal activity against 16 clinical Candida albicans and the compound analysis was performed using gas chromatography-mass spectrometry GC-MS. The 31 actinobacterial strains were isolated and 16S rRNA gene sequencing revealed that this ecosystem is rich on actinobacteria, with Streptomyces as the predominant genus. The PCR based screening of biosynthetic genes revealed the presence of PKS-I in six strains, PKS-II in four strains and NRPS in 11 strains. The isolated actinobacteria VITGAP240 and VITGAP241 (two isolates) were found to have a potential antifungal activity against all the tested C. albicans . GC-MS results revealed that the actinobacterial compounds were belonging to heterocyclic, polyketides and peptides. Overall, the strains possess a wide spectrum of antifungal properties which affords the production of significant bioactive metabolites as potential antibiotics.

  11. [Trichophyton tonsurans associated with non-albicans Candida species in hands onychomycosis about a Moroccan case].

    Science.gov (United States)

    Kouara, S; Ait Hlilou, B; Abbadi, A; Khalki, H; Benbella, I; Lahmadi, K; Er-Rami, M

    2017-03-01

    Trichophyton tonsurans is an anthropophilic dermatophyte, frequent in the USA and in Asia where it is responsible for causing tinea capitis. At present, we attend an emergence of this species in certain regions where it was not or little met. Here, we report a case of onychomycosis of the hand due to T. tonsurans associated with non-albicans Candida species at an adult woman. The patient is a 62-year-old woman, with hypertension and diabetes. She reports the rather frequent use of chemical cleaners for the housework. She presented one year previously a distal onycholysis of the last four fingers of the left hand. The clinical examination objectified a presence of intertrigo in the second interdigital space. The mycological examination showed at the direct examination mycelial elements and the culture allowed the isolation of T. tonsurans associated with non-albicans Candida species. Our observation highlights especially the identification of a species, which has been described only once in Morocco about a case with onychomycosis of the feet. A possible emergence of this species in our country is not far from being possible. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Activities of Fluconazole, Caspofungin, Anidulafungin, and Amphotericin B on Planktonic and Biofilm Candida Species Determined by Microcalorimetry

    Science.gov (United States)

    Maiolo, Elena Maryka; Furustrand Tafin, Ulrika; Borens, Olivier

    2014-01-01

    We investigated the activities of fluconazole, caspofungin, anidulafungin, and amphotericin B against Candida species in planktonic form and biofilms using a highly sensitive assay measuring growth-related heat production (microcalorimetry). C. albicans, C. glabrata, C. krusei, and C. parapsilosis were tested, and MICs were determined by the broth microdilution method. The antifungal activities were determined by isothermal microcalorimetry at 37°C in RPMI 1640. For planktonic Candida, heat flow was measured in the presence of antifungal dilutions for 24 h. Candida biofilm was formed on porous glass beads for 24 h and exposed to serial dilutions of antifungals for 24 h, and heat flow was measured for 48 h. The minimum heat inhibitory concentration (MHIC) was defined as the lowest antifungal concentration reducing the heat flow peak by ≥50% (≥90% for amphotericin B) at 24 h for planktonic Candida and at 48 h for Candida biofilms (measured also at 24 h). Fluconazole (planktonic MHICs, 0.25 to >512 μg/ml) and amphotericin B (planktonic MHICs, 0.25 to 1 μg/ml) showed higher MHICs than anidulafungin (planktonic MHICs, 0.015 to 0.5 μg/ml) and caspofungin (planktonic MHICs, 0.125 to 0.5 μg/ml). Against Candida species in biofilms, fluconazole's activity was reduced by >1,000-fold compared to its activity against the planktonic counterparts, whereas echinocandins and amphotericin B mainly preserved their activities. Fluconazole induced growth of planktonic C. krusei at sub-MICs. At high concentrations of caspofungin (>4 μg/ml), paradoxical growth of planktonic C. albicans and C. glabrata was observed. Microcalorimetry enabled real-time evaluation of antifungal activities against planktonic and biofilm Candida organisms. It can be used in the future to evaluate new antifungals and antifungal combinations and to study resistant strains. PMID:24566186

  13. Impact of Hydrodynamics on Oral Biofilm Strength

    NARCIS (Netherlands)

    Paramonova, E.; Kalmykowa, O. J.; van der Mei, H. C.; Busscher, H. J.; Sharma, P. K.

    2009-01-01

    Mechanical removal of oral biofilms is ubiquitously accepted as the best way to prevent caries and periodontal diseases. Removal effectiveness strongly depends on biofilm strength. To investigate the influence of hydrodynamics on oral biofilm strength, we grew single- and multi-species biofilms of

  14. Confocal microscopy imaging of the biofilm matrix

    DEFF Research Database (Denmark)

    Schlafer, Sebastian; Meyer, Rikke L

    2017-01-01

    The extracellular matrix is an integral part of microbial biofilms and an important field of research. Confocal laser scanning microscopy is a valuable tool for the study of biofilms, and in particular of the biofilm matrix, as it allows real-time visualization of fully hydrated, living specimens...... the concentration of solutes and the diffusive properties of the biofilm matrix....

  15. Oral Biofilm Architecture on Natural Teeth

    NARCIS (Netherlands)

    Zijnge, Vincent; van Leeuwen, M. Barbara M.; Degener, John E.; Abbas, Frank; Thurnheer, Thomas; Gmuer, Rudolf; Harmsen, Hermie J. M.

    2010-01-01

    Periodontitis and caries are infectious diseases of the oral cavity in which oral biofilms play a causative role. Moreover, oral biofilms are widely studied as model systems for bacterial adhesion, biofilm development, and biofilm resistance to antibiotics, due to their widespread presence and

  16. Bacterial biofilms: prokaryotic adventures in multicellularity

    DEFF Research Database (Denmark)

    Webb, J.S.; Givskov, Michael Christian; Kjelleberg, S.

    2003-01-01

    The development of bacterial biofilms includes both the initial social behavior of undifferentiated cells, as well as cell death and differentiation in the mature biofilm, and displays several striking similarities with higher organisms. Recent advances in the field provide new insight...... into differentiation and cell death events in bacterial biofilm development and propose that biofilms have an unexpected level of multicellularity....

  17. The Small Molecule DAM Inhibitor, Pyrimidinedione, Disrupts Streptococcus pneumoniae Biofilm Growth In Vitro.

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar Yadav

    -clumps were scattered and attached to the bottom of the plate when cells were grown in the presence of pyrimidinedione. Scanning electron microscopy analysis demonstrated the absence of an extracellular polysaccharide matrix in pyrimidinedione-grown biofilms compared to control-biofilms. Pyrimidinedione also significantly inhibited MRSA, MSSA, and Staphylococcus epidermidis biofilm growth in vitro. Furthermore, pyrimidinedione does not exhibit eukaryotic cell toxicity. In a microarray analysis, 56 genes were significantly up-regulated and 204 genes were significantly down-regulated. Genes involved in galactose metabolism were exclusively up-regulated in pyrimidinedione-grown biofilms. Genes related to DNA replication, cell division and the cell cycle, pathogenesis, phosphate-specific transport, signal transduction, fatty acid biosynthesis, protein folding, homeostasis, competence, and biofilm formation were down regulated in pyrimidinedione-grown biofilms. This study demonstrated that the small molecule Dam inhibitor, pyrimidinedione, inhibits pneumococcal biofilm growth in vitro at concentrations that do not inhibit planktonic cell growth and down regulates important metabolic-, virulence-, competence-, and biofilm-related genes. The identification of a small molecule (pyrimidinedione with S. pneumoniae biofilm-inhibiting capabilities has potential for the development of new compounds that prevent biofilm formation.

  18. 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.

  19. Significance of polymethylmethacrylate (PMMA) modification by zinc oxide nanoparticles for fungal biofilm formation.

    Science.gov (United States)

    Cierech, Mariusz; Kolenda, Adam; Grudniak, Anna M; Wojnarowicz, Jacek; Woźniak, Bartosz; Gołaś, Marlena; Swoboda-Kopeć, Ewa; Łojkowski, Witold; Mierzwińska-Nastalska, Elżbieta

    2016-08-20

    The objective of this study was to obtain a material composite with antifungal properties for dentures to be used as an alternative protocol in denture stomatitis treatment and prevention. Denture stomatitis is still a clinical problem in patients particularly vulnerable to this disease. Composites of PMMA and doped ZnO-NPs (weight concentrations, 2.5%, 5%, 7.5%) and PMMA with sprayed solvothermal and hydrothermal ZnO-NPs were tested. The following investigations of newly formed biomaterials were undertaken: influence on Candida albicans solution, biofilm staining, XTT analysis and a quantitative analysis of adhered C. albicans. These studies evidenced the antifungal activity of both nanocomposites PMMA-ZnO-NPs and the efficacy of sputtering of zinc oxide nanoparticles on the PMMA. The study of the biofilm deposition on the surface showed that antifungal properties increase with increasing concentration of ZnO-NPs. The XTT assay in conjunction with testing the turbidity of solutions may indicate the mechanism by which ZnO-NPs exert their effect on the increased induction of antioxidative stress in microorganism cells. The denture base made of the aforesaid materials may play a preventive role in patients susceptible to fungal infections. Based on the results obtained a modified treatment of stomatitis Type II (Newton's classification) complicated by fungal infection was proposed. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Rapid Methods for the Laboratory Identification of Pathogenic Microorganisms.

    Science.gov (United States)

    1982-09-01

    coli Hemophilus influenzae Bacillus anthracis Bacillus circulans Bacillus coagulans Bacillus cereus T Candida albicans Cryptococcus neoformans Legionel...reveree aide If neceeeary and Identify by block number) Lectins: Rapid Identification, Bacillus anthracisjCryptococcus " neoformans. Neisseria...field-type kit for the rapid identification of Bacillus anthracis. We have shown that certain lectins will selectively interact with B. anthracis

  1. 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

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

    Directory of Open Access Journals (Sweden)

    Bokor-Bratić Marija B.

    2008-01-01

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

  3. Growing and analyzing biofilms in flow chambers

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Sternberg, Claus

    2011-01-01

    This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic......, and disassembly and cleaning of the system. In addition, embedding and fluorescent in situ hybridization of flow chamber-grown biofilms are addressed....

  4. Molecular methods for biofilms

    KAUST Repository

    Ferrera, Isabel; Balagué , Vanessa; Voolstra, Christian R.; Aranda, Manuel; Bayer, Till; Abed, Raeid M.M.; Dobretsov, Sergey; Owens, Sarah M.; Wilkening, Jared; Fessler, Jennifer L.; Gilbert, Jack A.

    2014-01-01

    This chapter deals with both classical and modern molecular methods that can be useful for the identification of microorganisms, elucidation and comparison of microbial communities, and investigation of their diversity and functions. The most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples; these are discussed in the first part. The second part provides an overview over DNA polymerase chain reaction (PCR) amplification and DNA sequencing methods. Protocols and analysis software as well as potential pitfalls associated with application of these methods are discussed. Community fingerprinting analyses that can be used to compare multiple microbial communities are discussed in the third part. This part focuses on Denaturing Gradient Gel Electrophoresis (DGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP) and Automated rRNA Intergenic Spacer Analysis (ARISA) methods. In addition, classical and next-generation metagenomics methods are presented. These are limited to bacterial artificial chromosome and Fosmid libraries and Sanger and next-generation 454 sequencing, as these methods are currently the most frequently used in research. Isolation of nucleic acids: This chapter discusses, the most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples. Nucleic acid isolation methods generally include three steps: cell lysis, removal of unwanted substances, and a final step of DNA purification and recovery. The first critical step is the cell lysis, which can be achieved by enzymatic or mechanical procedures. Removal of proteins, polysaccharides and other unwanted substances is likewise important to avoid their interference in subsequent analyses. Phenol-chloroform-isoamyl alcohol is commonly used to recover DNA, since it separates nucleic acids into an aqueous phase and precipitates proteins and

  5. Molecular methods for biofilms

    KAUST Repository

    Ferrera, Isabel

    2014-08-30

    This chapter deals with both classical and modern molecular methods that can be useful for the identification of microorganisms, elucidation and comparison of microbial communities, and investigation of their diversity and functions. The most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples; these are discussed in the first part. The second part provides an overview over DNA polymerase chain reaction (PCR) amplification and DNA sequencing methods. Protocols and analysis software as well as potential pitfalls associated with application of these methods are discussed. Community fingerprinting analyses that can be used to compare multiple microbial communities are discussed in the third part. This part focuses on Denaturing Gradient Gel Electrophoresis (DGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP) and Automated rRNA Intergenic Spacer Analysis (ARISA) methods. In addition, classical and next-generation metagenomics methods are presented. These are limited to bacterial artificial chromosome and Fosmid libraries and Sanger and next-generation 454 sequencing, as these methods are currently the most frequently used in research. Isolation of nucleic acids: This chapter discusses, the most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples. Nucleic acid isolation methods generally include three steps: cell lysis, removal of unwanted substances, and a final step of DNA purification and recovery. The first critical step is the cell lysis, which can be achieved by enzymatic or mechanical procedures. Removal of proteins, polysaccharides and other unwanted substances is likewise important to avoid their interference in subsequent analyses. Phenol-chloroform-isoamyl alcohol is commonly used to recover DNA, since it separates nucleic acids into an aqueous phase and precipitates proteins and

  6. Unintended Laboratory-Driven Evolution Reveals Genetic Requirements for Biofilm Formation by Desulfovibrio vulgaris Hildenborough

    Directory of Open Access Journals (Sweden)

    Kara B. De León

    2017-10-01

    Full Text Available Biofilms of sulfate-reducing bacteria (SRB are of particular interest as members of this group are culprits in corrosion of industrial metal and concrete pipelines as well as being key players in subsurface metal cycling. Yet the mechanism of biofilm formation by these bacteria has not been determined. Here we show that two supposedly identical wild-type cultures of the SRB Desulfovibrio vulgaris Hildenborough maintained in different laboratories have diverged in biofilm formation. From genome resequencing and subsequent mutant analyses, we discovered that a single nucleotide change within DVU1017, the ABC transporter of a type I secretion system (T1SS, was sufficient to eliminate biofilm formation in D. vulgaris Hildenborough. Two T1SS cargo proteins were identified as likely biofilm structural proteins, and the presence of at least one (with either being sufficient was shown to be required for biofilm formation. Antibodies specific to these biofilm structural proteins confirmed that DVU1017, and thus the T1SS, is essential for localization of these adhesion proteins on the cell surface. We propose that DVU1017 is a member of the lapB category of microbial surface proteins because of its phenotypic similarity to the adhesin export system described for biofilm formation in the environmental pseudomonads. These findings have led to the identification of two functions required for biofilm formation in D. vulgaris Hildenborough and focus attention on the importance of monitoring laboratory-driven evolution, as phenotypes as fundamental as biofilm formation can be altered.

  7. 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.

  8. 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.)

  9. Conductive properties of methanogenic biofilms.

    Science.gov (United States)

    Li, Cheng; Lesnik, Keaton Larson; Liu, Hong

    2018-02-01

    Extracellular electron transfer between syntrophic partners needs to be efficiently maintained in methanogenic environments. Direct extracellular electron transfer via electrical current is an alternative to indirect hydrogen transfer but requires construction of conductive extracellular structures. Conductive mechanisms and relationship between conductivity and the community composition in mixed-species methanogenic biofilms are not well understood. The present study investigated conductive behaviors of methanogenic biofilms and examined the correlation between biofilm conductivity and community composition between different anaerobic biofilms enriched from the same inoculum. Highest conductivity observed in methanogenic biofilms was 71.8±4.0μS/cm. Peak-manner response of conductivity upon changes over a range of electrochemical potentials suggests that electron transfer in methanogenic biofilms occurs through redox driven super-exchange. The strong correlation observed between biofilm conductivity and Geobacter spp. in the metabolically diverse anaerobic communities suggests that the efficiency of DEET may provide pressure for microbial communities to select for species that can produce electrical conduits. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Biofilm models for the practitioner

    DEFF Research Database (Denmark)

    Morgenroth, Eberhard Friedrich; van Loosdrecht, M. C. M.; Wanner, O.

    2000-01-01

    Even though mathematical biofilm models are extensively used in biofilm research, there has been very little application of these models in the engineering practice so far. However, practitioners would be interested in models that can be used as tools to control plant operation under dynamic...... conditions or to help them handle complex interactions between particle removal, carbon oxidation, nitrification, denitrification and biological phosphorus removal. But even though there is a whole range of biofilm models available, it is difficult for the practitioner to select the appropriate modeling...

  11. Stratified growth in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Werner, E.; Roe, F.; Bugnicourt, A.

    2004-01-01

    In this study, stratified patterns of protein synthesis and growth were demonstrated in Pseudomonas aeruginosa biofilms. Spatial patterns of protein synthetic activity inside biofilms were characterized by the use of two green fluorescent protein (GFP) reporter gene constructs. One construct...... synthesis was restricted to a narrow band in the part of the biofilm adjacent to the source of oxygen. The zone of active GFP expression was approximately 60 Am wide in colony biofilms and 30 Am wide in flow cell biofilms. The region of the biofilm in which cells were capable of elongation was mapped...... by treating colony biofilms with carbenicillin, which blocks cell division, and then measuring individual cell lengths by transmission electron microscopy. Cell elongation was localized at the air interface of the biofilm. The heterogeneous anabolic patterns measured inside these biofilms were likely a result...

  12. Novel method for quantitative estimation of biofilms

    DEFF Research Database (Denmark)

    Syal, Kirtimaan

    2017-01-01

    Biofilm protects bacteria from stress and hostile environment. Crystal violet (CV) assay is the most popular method for biofilm determination adopted by different laboratories so far. However, biofilm layer formed at the liquid-air interphase known as pellicle is extremely sensitive to its washing...... and staining steps. Early phase biofilms are also prone to damage by the latter steps. In bacteria like mycobacteria, biofilm formation occurs largely at the liquid-air interphase which is susceptible to loss. In the proposed protocol, loss of such biofilm layer was prevented. In place of inverting...... and discarding the media which can lead to the loss of the aerobic biofilm layer in CV assay, media was removed from the formed biofilm with the help of a syringe and biofilm layer was allowed to dry. The staining and washing steps were avoided, and an organic solvent-tetrahydrofuran (THF) was deployed...

  13. Albicans candidiasis amongs women and infants at two health ...

    African Journals Online (AJOL)

    Albicans candidiasis amongs women and infants at two health facilities in Port ... and in infants – Oral Thrush (OT) was investigated in Port Harcourt, Rivers State. ... UPTH (28.6%) had more infection rate than BMSH (22.9%), pregnant women ...

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

    Directory of Open Access Journals (Sweden)

    Fikadu G Tafesse

    2015-10-01

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

  15. Host defence against disseminated and invasive candida albicans infections.

    NARCIS (Netherlands)

    Vonk, A.G.

    2004-01-01

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

  16. Hydrodynamic dispersion within porous biofilms

    KAUST Repository

    Davit, Y.; Byrne, H.; Osborne, J.; Pitt-Francis, J.; Gavaghan, D.; Quintard, M.

    2013-01-01

    Many microorganisms live within surface-associated consortia, termed biofilms, that can form intricate porous structures interspersed with a network of fluid channels. In such systems, transport phenomena, including flow and advection, regulate

  17. Exploiting social evolution in biofilms

    DEFF Research Database (Denmark)

    Boyle, Kerry E; Heilmann, Silja; van Ditmarsch, Dave

    2013-01-01

    Bacteria are highly social organisms that communicate via signaling molecules, move collectively over surfaces and make biofilm communities. Nonetheless, our main line of defense against pathogenic bacteria consists of antibiotics-drugs that target individual-level traits of bacterial cells...... and thus, regrettably, select for resistance against their own action. A possible solution lies in targeting the mechanisms by which bacteria interact with each other within biofilms. The emerging field of microbial social evolution combines molecular microbiology with evolutionary theory to dissect...... the molecular mechanisms and the evolutionary pressures underpinning bacterial sociality. This exciting new research can ultimately lead to new therapies against biofilm infections that exploit evolutionary cheating or the trade-off between biofilm formation and dispersal....

  18. Biofilms: Community Behavior by Bacteria

    Indian Academy of Sciences (India)

    IAS Admin

    United we stand, divided we fall. This is a ... controls biofilm development, swarming motility and the produc- ... thought that the absence of overt gut flora upsets the balance .... there are several risks of integration which makes this strategy.

  19. Compaction and relaxation of biofilms

    KAUST Repository

    Valladares Linares, R.; Wexler, A. D.; Bucs, Szilard; Dreszer, C.; Zwijnenburg, A.; Flemming, H. C.; Kruithof, J. C.; Vrouwenvelder, Johannes S.

    2015-01-01

    Operation of membrane systems for water treatment can be seriously hampered by biofouling. A better characterization of biofilms in membrane systems and their impact on membrane performance may help to develop effective biofouling control strategies

  20. Biofilm in endodontics: a review

    OpenAIRE

    Zambrano de la Peña, Sonia; Salcedo-Moncada, Doris; Petkova- Gueorguieva, Marieta; Ventocilla Huasupoma, María

    2017-01-01

    It is demonstrated the efforts made endodontic microbiology and science to get to decipher the secrets of this unique structure although every day new questions arise. We need the treatments we use to combat biofilm achieve oxygenate the periapical ecosystem and basically scrape and loosen the tightly adhering bacteria Knowing the process of biofilm formation, microbial metabolism and strategies that they use to resist and remain hidden but active , we know why we observe refractory periapica...

  1. Critical review on biofilm methods

    DEFF Research Database (Denmark)

    Azeredo, Joana; F. Azevedo, Nuno; Briandet, Romain

    2017-01-01

    Biofilms are widespread in nature and constitute an important strategy implemented by microorganisms to survive in sometimes harsh environmental conditions. They can be beneficial or have a negative impact particularly when formed in industrial settings or on medical devices. As such, research in...... and limitations of several methods. Accordingly, this review aims at helping scientists in finding the most appropriate and up-to-date methods to study their biofilms....

  2. The Emerging Pathogen Candida auris: Growth Phenotype, Virulence Factors, Activity of Antifungals, and Effect of SCY-078, a Novel Glucan Synthesis Inhibitor, on Growth Morphology and Biofilm Formation.

    Science.gov (United States)

    Larkin, Emily; Hager, Christopher; Chandra, Jyotsna; Mukherjee, Pranab K; Retuerto, Mauricio; Salem, Iman; Long, Lisa; Isham, Nancy; Kovanda, Laura; Borroto-Esoda, Katyna; Wring, Steve; Angulo, David; Ghannoum, Mahmoud

    2017-05-01

    Candida auris , a new multidrug-resistant Candida spp. which is associated with invasive infection and high rates of mortality, has recently emerged. Here, we determined the virulence factors (germination, adherence, biofilm formation, phospholipase and proteinase production) of 16 C. auris isolates and their susceptibilities to 11 drugs belonging to different antifungal classes, including a novel orally bioavailable 1,3-β-d-glucan synthesis inhibitor (SCY-078). We also examined the effect of SCY-078 on the growth, ultrastructure, and biofilm-forming abilities of C. auris Our data showed that while the tested strains did not germinate, they did produce phospholipase and proteinase in a strain-dependent manner and had a significantly reduced ability to adhere and form biofilms compared to that of Candida albicans ( P = 0.01). C. auris isolates demonstrated reduced susceptibility to fluconazole and amphotericin B, while, in general, they were susceptible to the remaining drugs tested. SCY-078 had an MIC 90 of 1 mg/liter against C. auris and caused complete inhibition of the growth of C. auris and C. albicans Scanning electron microscopy analysis showed that SCY-078 interrupted C. auris cell division, with the organism forming abnormal fused fungal cells. Additionally, SCY-078 possessed potent antibiofilm activity, wherein treated biofilms demonstrated significantly reduced metabolic activity and a significantly reduced thickness compared to the untreated control ( P < 0.05 for both comparisons). Our study shows that C. auris expresses several virulence determinants (albeit to a lesser extent than C. albicans ) and is resistant to fluconazole and amphotericin B. SCY-078, the new orally bioavailable antifungal, had potent antifungal/antibiofilm activity against C. auris , indicating that further evaluation of this antifungal is warranted. Copyright © 2017 Larkin et al.

  3. Streptococcus mutans Protein Synthesis during Mixed-Species Biofilm Development by High-Throughput Quantitative Proteomics

    Science.gov (United States)

    Klein, Marlise I.; Xiao, Jin; Lu, Bingwen; Delahunty, Claire M.; Yates, John R.; Koo, Hyun

    2012-01-01

    Biofilms formed on tooth surfaces are comprised of mixed microbiota enmeshed in an extracellular matrix. Oral biofilms are constantly exposed to environmental changes, which influence the microbial composition, matrix formation and expression of virulence. Streptococcus mutans and sucrose are key modulators associated with the evolution of virulent-cariogenic biofilms. In this study, we used a high-throughput quantitative proteomics approach to examine how S. mutans produces relevant proteins that facilitate its establishment and optimal survival during mixed-species biofilms development induced by sucrose. Biofilms of S. mutans, alone or mixed with Actinomyces naeslundii and Streptococcus oralis, were initially formed onto saliva-coated hydroxyapatite surface under carbohydrate-limiting condition. Sucrose (1%, w/v) was then introduced to cause environmental changes, and to induce biofilm accumulation. Multidimensional protein identification technology (MudPIT) approach detected up to 60% of proteins encoded by S. mutans within biofilms. Specific proteins associated with exopolysaccharide matrix assembly, metabolic and stress adaptation processes were highly abundant as the biofilm transit from earlier to later developmental stages following sucrose introduction. Our results indicate that S. mutans within a mixed-species biofilm community increases the expression of specific genes associated with glucan synthesis and remodeling (gtfBC, dexA) and glucan-binding (gbpB) during this transition (Pmutans up-regulates specific adaptation mechanisms to cope with acidic environments (F1F0-ATPase system, fatty acid biosynthesis, branched chain amino acids metabolism), and molecular chaperones (GroEL). Interestingly, the protein levels and gene expression are in general augmented when S. mutans form mixed-species biofilms (vs. single-species biofilms) demonstrating fundamental differences in the matrix assembly, survival and biofilm maintenance in the presence of other

  4. Isolation of Extracellular Polymeric Substances from Biofilms of the Thermoacidophilic Archaeon Sulfolobus acidocaldarius.

    Science.gov (United States)

    Jachlewski, Silke; Jachlewski, Witold D; Linne, Uwe; Bräsen, Christopher; Wingender, Jost; Siebers, Bettina

    2015-01-01

    Extracellular polymeric substances (EPS) are the major structural and functional components of microbial biofilms. The aim of this study was to establish a method for EPS isolation from biofilms of the thermoacidophilic archaeon, Sulfolobus acidocaldarius, as a basis for EPS analysis. Biofilms of S. acidocaldarius were cultivated on the surface of gellan gum-solidified Brock medium at 78°C for 4 days. Five EPS extraction methods were compared, including shaking of biofilm suspensions in phosphate buffer, cation-exchange resin (CER) extraction, and stirring with addition of EDTA, crown ether, or NaOH. With respect to EPS yield, impact on cell viability, and compatibility with subsequent biochemical analysis, the CER extraction method was found to be the best suited isolation procedure resulting in the detection of carbohydrates and proteins as the major constituents and DNA as a minor component of the EPS. Culturability of CER-treated cells was not impaired. Analysis of the extracellular proteome using two-dimensional gel electrophoresis resulted in the detection of several hundreds of protein spots, mainly with molecular masses of 25-116 kDa and pI values of 5-8. Identification of proteins suggested a cytoplasmic origin for many of these proteins, possibly released via membrane vesicles or biofilm-inherent cell lysis during biofilm maturation. Functional analysis of EPS proteins, using fluorogenic substrates as well as zymography, demonstrated the activity of diverse enzyme classes, such as proteases, lipases, esterases, phosphatases, and glucosidases. In conclusion, the CER extraction method, as previously applied to bacterial biofilms, also represents a suitable method for isolation of water soluble EPS from the archaeal biofilms of S. acidocaldarius, allowing the investigation of composition and function of EPS components in these types of biofilms.

  5. Isolation of extracellular polymeric substances from biofilms of the thermoacidophilic archaeon Sulfolobus acidocaldarius

    Directory of Open Access Journals (Sweden)

    Silke eJachlewski

    2015-08-01

    Full Text Available Extracellular polymeric substances (EPS are the major structural and functional components of microbial biofilms. The aim of this study was to establish a method for EPS isolation from biofilms of the thermoacidophilic archaeon Sulfolobus acidocaldarius as a basis for EPS analysis. Biofilms of S. acidocaldarius were cultivated on the surface of gellan gum-solidified Brock medium at 78 °C for 4 days. Five EPS extraction methods were compared, including shaking of biofilm suspensions in phosphate buffer, cation-exchange resin (CER extraction and stirring with addition of EDTA, crown ether or NaOH. With respect to EPS yield, impact on cell viability and compatibility with subsequent biochemical analysis, the CER extraction method was found to be the best suited isolation procedure resulting in the detection of carbohydrates and proteins as the major constituents and DNA as a minor component of the EPS. Culturability of CER-treated cells was not impaired. Analysis of the extracellular proteome using two-dimensional gel electrophoresis resulted in the detection of several hundredshundred of protein spots, mainly with molecular masses of 25 kDa to 116 kDa and pI values of 5 to 8. Identification of proteins suggested a cytoplasmic origin for many of these proteins, possibly released via membrane vesicles or biofilm-inherent cell lysis during biofilm maturation. Functional analysis of EPS proteins, using fluorogenic substrates as well as zymography, demonstrated the activity of diverse groups of enzymes such as proteases, lipases, esterases, phosphatases and glucosidases. In conclusion, the CER extraction method, as previously applied to bacterial biofilms, also represents a suitable method for isolation of water soluble EPS from the archaeal biofilms of S. acidocaldarius, allowing the investigation of composition and function of EPS components in these types of biofilms.

  6. In vitro biofilm forming capacity on abiotic contact surfaces by outbreak-associated Vibrio harveyi strains

    Directory of Open Access Journals (Sweden)

    Pallaval Veera Bramha Chari

    2014-02-01

    Full Text Available Objective: To evaluate the in vitro biofilm forming capacity on abiotic food contact surfaces by Vibrio harveyi (V. harveyi strains. Methods: Thirty six Gram-negative V. harveyi strains were isolated from various street vended seafood outlets in a food processing line and evaluated for their ability to produce mucoid biofilms on food contact surfaces using a microplate assay. Phenotypic characterization of mucoid biofilm producing V. harveyi strains were screened on Congo red agar, thiosulfate-citrate-bile salts-sucrose agar and tryptic soy agar, respectively. Results: Only five V. harveyi strains (14% were mucoid biofilm producers characterized by formation of black colonies, whereas the remaining 31 strains (86% were not capable of producing biofilm characterized by formation of red colonies or pinkish-red colonies with darkening at the centre. The morphological, physiological and biochemical characteristics of these isolates were studied using standard protocols. Strain identification was confirmed by polymerase chain reaction targeted to species-specific polymerase chain reaction primers VH-1 and VH-2 corresponding to variable regions of V. harveyi 16S rRNA sequence. All the biofilm-forming strains showed resistance to at least three antimicrobial compounds tested. V. harveyi strains isolated from various seafood were able to form biofilms of different capacity, and the strains VB267, VB238 and VB166 isolated from cat fish, shrimp and eel fish exhibited significantly greater biofilm forming ability compared to other isolates. Conclusions: It can be concluded from the present study that the strain VB166 was able to better attach and form subsequent biofilms on glass and stainless steel compared to high density polyethylene. These properties allow these bacteria to survive, proliferate and persist in street vended seafood outlets.

  7. Conservation and Divergence in the Candida Species Biofilm Matrix Mannan-Glucan Complex Structure, Function, and Genetic Control.

    Science.gov (United States)

    Dominguez, Eddie; Zarnowski, Robert; Sanchez, Hiram; Covelli, Antonio S; Westler, William M; Azadi, Parastoo; Nett, Jeniel; Mitchell, Aaron P; Andes, David R

    2018-04-03

    Candida biofilms resist the effects of available antifungal therapies. Prior studies with Candida albicans biofilms show that an extracellular matrix mannan-glucan complex (MGCx) contributes to antifungal sequestration, leading to drug resistance. Here we implement biochemical, pharmacological, and genetic approaches to explore a similar mechanism of resistance for the three most common clinically encountered non- albicans Candida species (NAC). Our findings reveal that each Candida species biofilm synthesizes a mannan-glucan complex and that the antifungal-protective function of this complex is conserved. Structural similarities extended primarily to the polysaccharide backbone (α-1,6-mannan and β-1,6-glucan). Surprisingly, biochemical analysis uncovered stark differences in the branching side chains of the MGCx among the species. Consistent with the structural analysis, similarities in the genetic control of MGCx production for each Candida species also appeared limited to the synthesis of the polysaccharide backbone. Each species appears to employ a unique subset of modification enzymes for MGCx synthesis, likely accounting for the observed side chain diversity. Our results argue for the conservation of matrix function among Candida spp. While biogenesis is preserved at the level of the mannan-glucan complex backbone, divergence emerges for construction of branching side chains. Thus, the MGCx backbone represents an ideal drug target for effective pan- Candida species biofilm therapy. IMPORTANCE Candida species, the most common fungal pathogens, frequently grow as a biofilm. These adherent communities tolerate extremely high concentrations of antifungal agents, due in large part, to a protective extracellular matrix. The present studies define the structural, functional, and genetic similarities and differences in the biofilm matrix from the four most common Candida species. Each species synthesizes an extracellular mannan-glucan complex (MGCx) which

  8. N-halamine-based rechargeable antimicrobial and biofilm-controlling polyurethane

    Science.gov (United States)

    Sun, Xinbo; Cao, Zhengbing; Porteous, Nuala; Sun, Yuyu

    2012-01-01

    An N-halamine precursor, 5, 5-dimethyl hydantoin (DMH), was covalently linked to the surface of polyurethane (PU) with 1,6-hexamethylene diisocyanate (HDI) as a coupling agent. The reaction pathways were investigated using propyl isocyanate (PI) as a model compound, and the results suggested that the imide and amide groups of DMH had very similar reactivity toward the isocyanate groups on PU surfaces activated with HDI. After bleach treatment, the covalently bound DMH moieties were transformed into N-halamines. The new N-halmaine-based PU provided potent antimicrobial effects against Staphylococcus aureus (S. aureus, Gram-positive), Escherichia coli (E. coli, Gram-negative), methicillin-resistant staphylococcus aureus (MRSA, drug resistant Gram-positive bacteria), vancomycin-resistant enterococcus (VRE, drug resistant Gram-positive bacteria), and Candida albicans (C. ablicans, fungi), and successfully prevented bacterial and fungal biofilm formation. The antimicrobial and biofilm-controlling effects were stable for longer than 6 months under normal storage in open air. Furthermore, if the functions were lost due to prolonged use, they could be recharged by another chlorination treatment. The recharging could be repeated as needed to achieve long-term protection against microbial contamination and biofilm-formation. PMID:22244984

  9. Ciliates as engineers of phototrophic biofilms

    NARCIS (Netherlands)

    Weerman, Ellen J.; van der Geest, Harm G.; van der Meulen, Myra D.; Manders, Erik M. M.; van de Koppel, Johan; Herman, Peter M. J.; Admiraal, Wim

    1. Phototrophic biofilms consist of a matrix of phototrophs, non-photosynthetic bacteria and extracellular polymeric substances (EPS) which is spatially structured. Despite widespread exploitation of algae and bacteria within phototrophic biofilms, for example by protozoans, the 'engineering'

  10. Current understanding of multi-species biofilms

    DEFF Research Database (Denmark)

    Yang, Liang; Liu, Yang; Wu, Hong

    2011-01-01

    every year worldwide to deal with damage to equipment, contaminations of products, energy losses, and infections in human beings resulted from microbial biofilms. Microorganisms compete, cooperate, and communicate with each other in multi-species biofilms. Understanding the mechanisms of multi......Direct observation of a wide range of natural microorganisms has revealed the fact that the majority of microbes persist as surface-attached communities surrounded by matrix materials, called biofilms. Biofilms can be formed by a single bacterial strain. However, most natural biofilms are actually......-species biofilm formation will facilitate the development of methods for combating bacterial biofilms in clinical, environmental, industrial, and agricultural areas. The most recent advances in the understanding of multi-species biofilms are summarized and discussed in the review....

  11. Killing of Serratia marcescens biofilms with chloramphenicol.

    Science.gov (United States)

    Ray, Christopher; Shenoy, Anukul T; Orihuela, Carlos J; González-Juarbe, Norberto

    2017-03-29

    Serratia marcescens is a Gram-negative bacterium with proven resistance to multiple antibiotics and causative of catheter-associated infections. Bacterial colonization of catheters mainly involves the formation of biofilm. The objectives of this study were to explore the susceptibility of S. marcescens biofilms to high doses of common antibiotics and non-antimicrobial agents. Biofilms formed by a clinical isolate of S. marcescens were treated with ceftriaxone, kanamycin, gentamicin, and chloramphenicol at doses corresponding to 10, 100 and 1000 times their planktonic minimum inhibitory concentration. In addition, biofilms were also treated with chemical compounds such as polysorbate-80 and ursolic acid. S. marcescens demonstrated susceptibility to ceftriaxone, kanamycin, gentamicin, and chloramphenicol in its planktonic form, however, only chloramphenicol reduced both biofilm biomass and biofilm viability. Polysorbate-80 and ursolic acid had minimal to no effect on either planktonic and biofilm grown S. marcescens. Our results suggest that supratherapeutic doses of chloramphenicol can be used effectively against established S. marcescens biofilms.

  12. Candida Biofilms: Development, Architecture, and Resistance

    Science.gov (United States)

    CHANDRA, JYOTSNA; MUKHERJEE, PRANAB K.

    2015-01-01

    Intravascular device–related infections are often associated with biofilms (microbial communities encased within a polysaccharide-rich extracellular matrix) formed by pathogens on the surfaces of these devices. Candida species are the most common fungi isolated from catheter-, denture-, and voice prosthesis–associated infections and also are commonly isolated from contact lens–related infections (e.g., fungal keratitis). These biofilms exhibit decreased susceptibility to most antimicrobial agents, which contributes to the persistence of infection. Recent technological advances have facilitated the development of novel approaches to investigate the formation of biofilms and identify specific markers for biofilms. These studies have provided extensive knowledge of the effect of different variables, including growth time, nutrients, and physiological conditions, on biofilm formation, morphology, and architecture. In this article, we will focus on fungal biofilms (mainly Candida biofilms) and provide an update on the development, architecture, and resistance mechanisms of biofilms. PMID:26350306

  13. 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.

  14. Cleaning and Disinfection of Bacillus cereus Biofilm.

    Science.gov (United States)

    Deal, Amanda; Klein, Dan; Lopolito, Paul; Schwarz, John Spencer

    2016-01-01

    Methodology has been evolving for the testing of disinfectants against bacterial single-species biofilms, as the difficulty of biofilm remediation continues to gain much-needed attention. Bacterial single-species biofilm contamination presents a real risk to good manufacturing practice-regulated industries. However, mixed-species biofilms and biofilms containing bacterial spores remain an even greater challenge for cleaning and disinfection. Among spore-forming microorganisms frequently encountered in pharmaceutical manufacturing areas, the spores of Bacillus cereus are often determined to be the hardest to disinfect and eradicate. One of the reasons for the low degree of susceptibility to disinfection is the ability of these spores to be encapsulated within an exopolysachharide biofilm matrix. In this series of experiments, we evaluated the disinfectant susceptibility of B. cereus biofilms relative to disassociated B. cereus spores and biofilm from a non-spore-forming species. Further, we assessed the impact that pre-cleaning has on increasing that susceptibility. Methodology has been evolving for the testing of disinfectants against bacterial single-species biofilms, as the difficulty of biofilm remediation continues to gain much-needed attention. Bacterial single-species biofilm contamination presents a real risk to good manufacturing practice-regulated industries. However, mixed-species biofilms and biofilms containing bacterial spores remain an even greater challenge for cleaning and disinfection. Among spore-forming microorganisms frequently encountered in pharmaceutical manufacturing areas, the spores of Bacillus cereus are often determined to be the hardest to disinfect and eradicate. One of the reasons for the low degree of susceptibility to disinfection is the ability of these spores to be encapsulated within an exopolysachharide biofilm matrix. In this series of experiments, we evaluated the disinfectant susceptibility of B. cereus biofilms relative to

  15. Maggot excretions inhibit biofilm formation on biomaterials.

    Science.gov (United States)

    Cazander, Gwendolyn; van de Veerdonk, Mariëlle C; Vandenbroucke-Grauls, Christina M J E; Schreurs, Marco W J; Jukema, Gerrolt N

    2010-10-01

    Biofilm-associated infections in trauma surgery are difficult to treat with conventional therapies. Therefore, it is important to develop new treatment modalities. Maggots in captured bags, which are permeable for larval excretions/secretions, aid in healing severe, infected wounds, suspect for biofilm formation. Therefore we presumed maggot excretions/secretions would reduce biofilm formation. We studied biofilm formation of Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella oxytoca, Enterococcus faecalis, and Enterobacter cloacae on polyethylene, titanium, and stainless steel. We compared the quantities of biofilm formation between the bacterial species on the various biomaterials and the quantity of biofilm formation after various incubation times. Maggot excretions/secretions were added to existing biofilms to examine their effect. Comb-like models of the biomaterials, made to fit in a 96-well microtiter plate, were incubated with bacterial suspension. The formed biofilms were stained in crystal violet, which was eluted in ethanol. The optical density (at 595 nm) of the eluate was determined to quantify biofilm formation. Maggot excretions/secretions were pipetted in different concentrations to (nonstained) 7-day-old biofilms, incubated 24 hours, and finally measured. The strongest biofilms were formed by S. aureus and S. epidermidis on polyethylene and the weakest on titanium. The highest quantity of biofilm formation was reached within 7 days for both bacteria. The presence of excretions/secretions reduced biofilm formation on all biomaterials. A maximum of 92% of biofilm reduction was measured. Our observations suggest maggot excretions/secretions decrease biofilm formation and could provide a new treatment for biofilm formation on infected biomaterials.

  16. 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.

  17. Effect of Algae and Plant Lectins on Planktonic Growth and Biofilm Formation in Clinically Relevant Bacteria and Yeasts

    Directory of Open Access Journals (Sweden)

    Mayron Alves Vasconcelos

    2014-01-01

    Full Text Available This study aimed to evaluate the abilities of plant and algae lectins to inhibit planktonic growth and biofilm formation in bacteria and yeasts. Initially, ten lectins were tested on Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella oxytoca, Pseudomonas aeruginosa, Candida albicans, and C. tropicalis at concentrations of 31.25 to 250 μg/mL. The lectins from Cratylia floribunda (CFL, Vatairea macrocarpa (VML, Bauhinia bauhinioides (BBL, Bryothamnion seaforthii (BSL, and Hypnea musciformis (HML showed activities against at least one microorganism. Biofilm formation in the presence of the lectins was also evaluated; after 24 h of incubation with the lectins, the biofilms were analyzed by quantifying the biomass (by crystal violet staining and by enumerating the viable cells (colony-forming units. The lectins reduced the biofilm biomass and/or the number of viable cells to differing degrees depending on the microorganism tested, demonstrating the different characteristics of the lectins. These findings indicate that the lectins tested in this study may be natural alternative antimicrobial agents; however, further studies are required to better elucidate the functional use of these proteins.

  18. Microbiële biofilms in tandheelkunde

    NARCIS (Netherlands)

    Krom, B.P.

    2015-01-01

    Aangehechte gemeenschappen van micro-organismen, ook wel biofilms genoemd, zijn altijd en overal aanwezig. Hoewel biofilms een slechte naam hebben, zijn ze meestal natuurlijk, gezond en zelfs gewenst. In de tandartspraktijk komen zowel gezonde (orale biofilms) als ongezonde (bijv. in de waterleiding

  19. Microbiële biofilms in tandheelkunde

    NARCIS (Netherlands)

    Krom, B.P.

    2015-01-01

    Aangehechte gemeenschappen van micro-organismen, ook wel biofilms genoemd, zijn altijd en overal aanwezig. Hoewel biofilms een slechte naam hebben, zijn ze meestal natuurlijk, gezond en zelfs gewenst. In de mondzorgpraktijk komen zowel gezonde (orale biofilms) als ongezonde (bijv. in de waterleiding

  20. Differential growth of wrinkled biofilms

    Science.gov (United States)

    Espeso, D. R.; Carpio, A.; Einarsson, B.

    2015-02-01

    Biofilms are antibiotic-resistant bacterial aggregates that grow on moist surfaces and can trigger hospital-acquired infections. They provide a classical example in biology where the dynamics of cellular communities may be observed and studied. Gene expression regulates cell division and differentiation, which affect the biofilm architecture. Mechanical and chemical processes shape the resulting structure. We gain insight into the interplay between cellular and mechanical processes during biofilm development on air-agar interfaces by means of a hybrid model. Cellular behavior is governed by stochastic rules informed by a cascade of concentration fields for nutrients, waste, and autoinducers. Cellular differentiation and death alter the structure and the mechanical properties of the biofilm, which is deformed according to Föppl-Von Kármán equations informed by cellular processes and the interaction with the substratum. Stiffness gradients due to growth and swelling produce wrinkle branching. We are able to reproduce wrinkled structures often formed by biofilms on air-agar interfaces, as well as spatial distributions of differentiated cells commonly observed with B. subtilis.

  1. Role of biofilm in cerebrospinal fluid shunt infections: A study at tertiary neurocare center from South India

    Directory of Open Access Journals (Sweden)

    Kirtilaxmi K Benachinmardi

    2017-01-01

    Full Text Available Introduction: Biofilms are the source of persistent infections of many pathogenic microbes. They are responsible for nosocomial infection and also associated with many surgical conditions including indwelling medical devices such as ventriculoperitoneal shunt. A significant problem encountered in shunt procedures is obstruction followed by infection, with infection rate ranging from 2% to 27%, often with poor outcome. Materials and Methods: This study was conducted in the Department of Neuromicrobiology at a tertiary neuroinstitute for 6 months from July 1 to December 31, 2014. The samples comprised cerebrospinal fluid (CSF from suspected cases of shunt infections. Laboratory diagnosis of causative agent was established by adopting standard procedures. Then, isolates were evaluated for production of biofilm by tissue culture plate (TCP method and tube method. Results: Of the 1642 shunt CSF samples obtained from neurosurgery, 14.79% were culture positive which yielded 254 isolates. About 51.97% were Gram-negative bacilli (GNB, 46.46% were Gram-positive cocci (GPC, and 1.57% were Candida albicans. Among GNB, nonfermenters were the most common (51.52% followed by Pseudomonas aeruginosa (15.9%. Among GPC, coagulase-negative Staphylococci were 88.13%, out of which 43.26% were methicillin-resistant. Other GPC were Enterococcus spp. (4.24%, Staphylococcus aureus (5.08%, and Streptococcus spp. (2.54%. Among all isolates, 120 were tested for biofilm production, out of which 57.5% were biofilm producers and 42.5% were nonproducers. Conclusions: TCP was the better method to detect biofilm. Most of the biofilm producers were resistant pathogens.

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

    Directory of Open Access Journals (Sweden)

    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

  3. Bmh1p (14-3-3) mediates pathways associated with virulence in Candida albicans.

    Science.gov (United States)

    Kelly, Michelle N; Johnston, Douglas A; Peel, Bethany A; Morgan, Timothy W; Palmer, Glen E; Sturtevant, Joy E

    2009-05-01

    The ability of the pathogenic fungus Candida albicans to cause disease requires rapid adaptation to changes in the host environment and to an evolving host immune response. The identification of 'virulence factors' using in vitro characterization of mutant strains has traditionally relied on a common set of phenotypic and biochemical assays (most often performed at 30 degrees C) and the subsequent correlation with their corresponding virulence in mouse models of disease. Utilizing a panel of isog