Purpurin suppresses Candida albicans biofilm formation and hyphal development

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Purpurin Triggers Caspase-Independent Apoptosis in Candida dubliniensis Biofilms

Candida dubliniensis is an important human fungal pathogen that causes oral infections in patients with AIDS and diabetes mellitus. However, C. Dubliniensis has been frequently reported in bloodstream infections in clinical settings. Like its phylogenetically related virulent species C. albicans, C. Dubliniensis is able to grow and switch between yeast form and filamentous form (hyphae) and develops biofilms on both abiotic and biotic surfaces. Biofilms are recalcitrant to antifungal therapies and C. Dubliniensis readily turns drug resistant upon repeated exposure. More than 80% of infections are associated with biofilms. Suppression of fungal biofilms may therefore represent a viable antifungal strategy with clinical relevance. Here, we report that C. dubliniensis biofilms were inhibited by purpurin, a natural anthraquinone pigment isolated from madder root. Purpurin inhibited C. dubliniensis biofilm formation in a concentration-dependent manner; while mature biofilms were less susceptible to purpurin. Scanning electron microscopy (SEM) analysis revealed scanty structure consisting of yeast cells in purpurin-treated C. dubliniensis biofilms. We sought to delineate the mechanisms of the anti-biofilm activity of purpurin on C. Dubliniensis. Intracellular ROS levels were significantly elevated in fungal biofilms and depolarization of MMP was evident upon purpurin treatment in a concentration-dependent manner. DNA degradation was evident. However, no activated metacaspase could be detected. Together, purpurin triggered metacaspase-independent apoptosis in C. dubliniensis biofilms.published_or_final_versio

Effect of Propolis on the Adhesion Index, Morphology and Viability of Candida albicans Cells on Biofilm Formation

Approximately 70-75% of reproductive women have experienced vulvovaginal candidiasis at least once, and 40-45% will have recurrences. Candida albicans is the most etiology of vulvovaginal candidiasis and is able to form a biofilm that can lead to antifungal resistances and recurrences. One of the natural products that have an anti biofilm effect is propolis. This study expected that propolis from Lawang can be one of the anti-biofilm agent candidates for antifungal resistant cases. This study aimed to know the anti-biofilm effect of propolis ethanol extract on cell adhesion index, morphology, and viability of Candida albicans cell on biofilm formation. The adhesion index was counted on 100 epithelial cells under light microscopy (1000x). Morphology was seen using light microscopy (400x). Cell viability was examined by CFU assay. At 12.5% concentration of propolis ethanol extract, adhesion index decreased (p=0,000), and hyphal growth was inhibited. Colony growth decreased at 2.5% concentration and was not seen at 10% concentration of propolis ethanol extract (p=0,000). These results indicated that propolis ethanol extract could decrease adhesion index, failed the Candida albicans morphology transition from yeast to hyphal, and decreased Candida albicans cell viability on biofilm formation. Propolis ethanol extract is likely to be one of the alternatives to recurrent vulvovaginal candidiasis treatment, especially caused by Candida albicans biofilm formation

EFFECT OF JAVANESE TURMERIC ETHANOL EXTRACT ON THE ERADICATION OF CANDIDA ALBICANS BIOFILMS IN EARLY, INTERMEDIATE, AND MATURATION PHASES

Objectives: The aim of this research was to observe the effect of Javanese turmeric ethanol extract (JTEE) on the eradication of Candida albicans invarious phases of biofilm development.Methods: C. albicans biofilms were exposed to JTEE at a concentration 1–45% for 1 h. Cell viability was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the wavelength was read at 570 nm.Results: The results showed that the 50% minimal biofilm eradication concentration was 30% in the early phase, 20% in the intermediate phase, and25% in the maturation phase of the biofilm. The eradication percentage increased along with increasing JTEE concentration, but decreased with theage of the biofilm.Conclusion: We concluded that JTEE has the potential to eradicate C. albicans biofilms in various phases of development

Malva sylvestris inhibits Candida albicans biofilm formation

Introduction: Candidiasis-associated biofilm formed by Candida species complicates treatment and contributes to unacceptable high mortality rates. We performed the aqueous and ethanol extracts of the different parts of Malva sylvestris, Dorema aucheri, Ferulago angulata and Citrullus colocynthis plants to identify best plant extract that inhibits growth of Candida albicans or Candida krusei, and conducted a series of follow-up studies to examine the inhibitors of C. albicans biofilm formation of the identified plant extract.Methods: The antifungal activities of the aqueous and ethanol extracts of the different parts of M. sylvestris, D. aucheri, F. angulata and C. colocynthis plants were evaluated in vitro using disk diffusion test and broth microdilution test against C. albicans and C. krusei. The crystal violet assay, morphological response and expression pattern of hyphal wall protein 1 (HWP1) gene were carried out to investigate the biofilm-inhibitory properties of the best plant extract tested in C. albicans.Results: The screen identified ethanol extract of M. sylvestris root that largely represented antifungal activity among the tested extracts. M. sylvestris root inhibited C. albicans biofilm formation. Ethanol extract of M. sylvestris root demonstrated significant reduction in C. albicans biofilm formation (P &lt; 0.005). Moreover, morphological observation of ethanol extract of M. sylvestris root treated cells confirmed a decrease in biofilm thickness and cellular density. Finally, ethanol extract of M. sylvestris root displayed significant down-regulation of HWP1.Conclusion: These results provide proof of concept for the implementation of ethanol extract of M. sylvestris root as inhibitor of C. albicans biofilm formation.</p

SEM Image of Candida Albicans Biofilms on Plastic Coupons

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Fungal biofilms: targets for the development of novel strategies in plant disease management

The global food supply has been facing increasing challenges during the first decades of the 21st century. Disease in plants is an important constraint to worldwide crop production, accounting for 20\u201340% of its annual harvest loss. Although the use of resistant varieties, good water management and agronomic practices are valid management tools in counteracting plant diseases, there are still many pathosystems where fungicides are widely used for disease management. However, restrictive regulations and increasing concern regarding the risk to human health and the environment, along with the incidence of fungicide resistance, have discouraged their use and have prompted for a search for new efficient, ecologically friendly and sustainable disease management strategies. The recent evidence of biofilm formation by fungal phytopathogens provides the scientific framework for designing and adapting methods and concepts developed by biofilm research that could be integrated in IPM practices. In this perspective paper, we provide evidence to support the view that the biofilm lifestyle plays a critical role in the pathogenesis of plant diseases. We describe the main factors limiting the durability of single-site fungicides, and we assemble the current knowledge on pesticide resistance in the specific context of the biofilm lifestyle. Finally, we illustrate the potential of antibiofilm compounds at sub-lethal concentrations for the development of an innovative, eco-sustainable strategy to counteract phytopathogenic fungi. Such fungicide-free solutions will be instrumental in reducing disease severity, and will permit more prudent use of fungicides decreasing thus the selection of resistant forms and safeguarding the environment

Fungal Morphogenesis

Morphogenesis in fungi is often induced by extracellular factors and executed by fungal genetic factors. Cell surface changes and alterations of the microenvironment often accompany morphogenetic changes in fungi. In this review, we will first discuss the general traits of yeast and hyphal morphotypes and how morphogenesis affects development and adaptation by fungi to their native niches, including host niches. Then we will focus on the molecular machinery responsible for the two most fundamental growth forms, yeast and hyphae. Last, we will describe how fungi incorporate exogenous environmental and host signals together with genetic factors to determine their morphotype and how morphogenesis, in turn, shapes the fungal microenvironment

Interaction between Candida albicans and Pseudomonas aeruginosa

Fungal pathogen Candida albicans causes serious nosocomial infections in patients, in part, due to formation of drug-resistant biofilms. Protein kinases (PK) and transcription factors (TF) mediate signal transduction and transcription of proteins involved in biofilm development. To discover biofilm-related PKs, a collection of 63 C. albicans PK mutants was screened twice independently with microtiter plate-based biofilm assay (XTT). Thirty-eight (60%) mutants showed different degrees of biofilm impairment with the poor biofilm formers additionally possessing filamentation defects. Most of these genes were already known to encode proteins associated with Candida morphology and biofilms but VPS15, PKH3, PGA43, IME2 and CEX1, were firstly associated with both processes in this study. Previous studies of Holcombe et al. (2010) had shown that bacterial pathogen, Pseudomonas aeruginosa can impair C. albicans filamentation and biofilm development. To investigate their interaction, the good biofilm former PK mutants of C. albicans were assessed for their response to P. aeruginosa supernatants derived from two strains, wildtype PAO1 and homoserine lactone (HSL)-free mutant ΔQS, without finding any nonresponsive mutants. This suggested that none of the PKs in this study was implicated in Candida-Pseudomonas signaling. To screen promoter sequences for overrepresented TFs across C. albicans gene sets significantly up/downregulated in presence of bacterial supernatants from Holcombe et al. (2010) study, TFbsST database was created online. The TFbsST database integrates experimentally verified TFs of Candida to analyse promoter sequences for TF binding sites. In silico studies predicted that Efg1p was overrepresented in C. albicans and C. parapsilosis RBT family genes