scholarly journals Sustained Nitric Oxide-Releasing Nanoparticles Induce Cell Death in Candida albicans Yeast and Hyphal Cells, Preventing Biofilm FormationIn Vitroand in a Rodent Central Venous Catheter Model

2016 ◽  
Vol 60 (4) ◽  
pp. 2185-2194 ◽  
Author(s):  
Mohammed S. Ahmadi ◽  
Hiu Ham Lee ◽  
David A. Sanchez ◽  
Adam J. Friedman ◽  
Moses T. Tar ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Candida Albicans ◽  
Flow Cytometric Analysis ◽  
Extracellular Polysaccharide ◽  
Host Cells ◽  
Yeast Cells ◽  
Central Venous ◽  
Content Type ◽  
Biofilm Development

ABSTRACTCandida albicansis a leading nosocomial pathogen. Today, candidal biofilms are a significant cause of catheter infections, and such infections are becoming increasingly responsible for the failure of medical-implanted devices.C. albicansforms biofilms in which fungal cells are encased in an autoproduced extracellular polysaccharide matrix. Consequently, the enclosed fungi are protected from antimicrobial agents and host cells, providing a unique niche conducive to robust microbial growth and a harbor for recurring infections. Here we demonstrate that a recently developed platform comprised of nanoparticles that release therapeutic levels of nitric oxide (NO-np) inhibits candidal biofilm formation, destroys the extracellular polysaccharide matrices of mature fungal biofilms, and hinders biofilm development on surface biomaterials such as the lumen of catheters. We found NO-np to decrease both the metabolic activity of biofilms and the cell viability ofC. albicansin vitroandin vivo. Furthermore, flow cytometric analysis found NO-np to induce apoptosis in biofilm yeast cellsin vitro. Moreover, NO-np behave synergistically when used in combination with established antifungal drug therapies. Here we propose NO-np as a novel treatment modality, especially in combination with standard antifungals, for the prevention and/or remediation of fungal biofilms on central venous catheters and other medical devices.

The ultrastructure of Candida albicans infections

1981 ◽  
Vol 27 (11) ◽  
pp. 1156-1164 ◽  
Author(s):  
Thomas J. Marrie ◽  
J. William Costerton
Keyword(s):  
Candida Albicans ◽  
Oral Candidiasis ◽  
Ruthenium Red ◽  
Host Cells ◽  
Yeast Cells ◽  
Positive Matrix ◽  
Urine Sediment ◽  
Bacteria Adhesion

Scrapings of Candida albicans plaques from the tongue and buccal mucosa of patients with oral candidiasis were examined electron microscopy. In addition, urine sediment from patients with infection of their catheterized urinary tracts was similar examined. Three types of C. albicans – oral epithelial cell interactions were noted: a loose adherence apparently mediated by ruthenium red positive matrix, a "tight" adherence where no space could be seen between the host and yeast cell, and invasions host cells by yeast hyphal elements. Adhesion of Candida blastospores to hyphal elements and adhesion of bacteria to Candida cells was also frequently observed.Urine sediments from patients with mixed bacteria–yeast infections demonstrated adhesion of the bacteria to the yeast cells. This phenomenon was also demonstrated in in vitro experiments and fibrous ruthenium red material invariably occupied the zo*** of adhesion.Phagocytosis of yeast by polymorphonuclear leukocytes was found in urinary, but not in oral, candidiasis. Our in vivo and vitro observations indicate that a ruthenium red positive matrix covers the surfaces involved in the yeast to yeast, yeast to ho and yeast to bacteria adhesion.

scholarly journals The “Finger,” a Unique Multicellular Morphology of Candida albicans Induced by CO2and Dependent upon the Ras1-Cyclic AMP Pathway

2012 ◽  
Vol 11 (10) ◽  
pp. 1257-1267 ◽  
Author(s):  
Karla J. Daniels ◽  
Claude Pujol ◽  
Thyagarajan Srikantha ◽  
David R. Soll
Keyword(s):  
Candida Albicans ◽  
Cyclic Amp ◽  
Mutational Analysis ◽  
Cell Monolayer ◽  
Yeast Cells ◽  
Content Type ◽  
Dispersal Mechanism ◽  
Basal Bulb ◽  
High Doses

ABSTRACTMost experiments exploring the basic biology of pathogenic microbes are performedin vitrounder conditions that do not usually mimic those of their host niche. Hence, developmental programs initiated by specific host cues may be missedin vitro. We have tested the effects of growing low-density agar cultures of the yeast pathogenCandida albicansin concentrations of CO2found in the gastrointestinal tract. It is demonstrated that in physiological concentrations of CO2at 37°C, yeast cells form a heretofore undescribed multicellular “finger” morphology distinct from a previously described stalk-like structure induced by high doses of UV irradiation that kills more than 99.99% of cells. The finger extends aerially, is uniform in diameter, and is visible to the naked eye, attaining lengths of 3 mm. It is composed of a basal yeast cell monolayer adhering to a semispherical crater formed in the agar and connected to a basal bulb of yeast cells at a fragile interface. The bulb extends into the long shaft. We propose that a single, centrally located hypha extending the length of the shaft forms buds at compartment junctions that serve as the source of the yeast cells in the shaft. A mutational analysis reveals finger formation is dependent upon the pathway Ras1→Cdc35→cyclic AMP (cAMP) (PDE2—|)→Tpk2→Tec1. Because of the mechanically fragile interface and the compactness of bulb and shaft, we suggest that the finger may function as a multicellular dispersal mechanism produced in host niches containing high levels of CO2.

scholarly journals Anti-Candidal Activity and In Vitro Cytotoxicity Assessment of Graphene Nanoplatelets Decorated with Zinc Oxide Nanorods

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 752 ◽  
Author(s):  
Graziella Ficociello ◽  
Maria De Caris ◽  
Giusy Trillò ◽  
Domenico Cavallini ◽  
Maria Sarto ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Candida Albicans ◽  
Pathogenic Fungus ◽  
In Vitro Cytotoxicity ◽  
Yeast Cells ◽  
Zinc Oxide Nanorods ◽  
Aggregation State ◽  
Oxide Nanorods ◽  
Biofilm Development

Candida albicans is the most common pathogenic fungus that is isolated in nosocomial infections in medically and immune-compromised patients. The ability of C. albicans to convert its form from yeast to hyphal morphology contributes to biofilm development that effectively shelters Candida against the action of antifungals molecules. In the last years, nanocomposites are the most promising solutions against drug-resistant microorganisms. The aim of this study was to investigate the antifungal activity of graphene nanoplateles decorated with zinc oxide nanorods (ZNGs) against the human pathogen Candida albicans. We observed that ZNGs were able to induce a significant mortality in fungal cells, as well as to affect the main virulence factors of this fungus or rather the hyphal development and biofilm formation. Reactive Oxygen Species (ROS) formation in yeast cells resulted one of the mechanisms of ZNGs to induce mortality. Finally, the toxicity of this nanomaterial was tested also on human keratinocyte cell line HaCaT. Our data indicated that ZNGs resulted not toxic when their aggregation state decreased by adding glycerol as emulsifier to ZNGs suspensions or when HaCaT cells were grown on ZNGs-coated glasses. Overall, the results that were obtained indicated that ZNGs could be exploited as an antifungal nanomaterial with a high degree of biocompatibility on human cells.

scholarly journals Symbiotic Relationship between Streptococcus mutans and Candida albicans Synergizes Virulence of Plaque BiofilmsIn Vivo

2014 ◽  
Vol 82 (5) ◽  
pp. 1968-1981 ◽  
Author(s):  
Megan L. Falsetta ◽  
Marlise I. Klein ◽  
Punsiri M. Colonne ◽  
Kathleen Scott-Anne ◽  
Stacy Gregoire ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Bacterial Pathogen ◽  
Single Species ◽  
Content Type ◽  
3 Dimensional ◽  
Biofilm Development

ABSTRACTStreptococcus mutansis often cited as the main bacterial pathogen in dental caries, particularly in early-childhood caries (ECC).S. mutansmay not act alone;Candida albicanscells are frequently detected along with heavy infection byS. mutansin 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 enhancedin vitroandin vivo. The presence ofC. albicansaugments the production of exopolysaccharides (EPS), such that cospecies biofilms accrue more biomass and harbor more viableS. mutanscells than single-species biofilms. The resulting 3-dimensional biofilm architecture displays sizeableS. mutansmicrocolonies 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. Ourin vitrodata also revealed that glucosyltransferase-derived EPS is a key mediator of cospecies biofilm development and that coexistence withC. albicansinduces the expression of virulence genes inS. mutans(e.g.,gtfB,fabM). We also found thatCandida-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.

scholarly journals Regulation of type 1 fimbriae synthesis and biofilm formation by the transcriptional regulator LrhA of Escherichia coli

Microbiology ◽  
2005 ◽  
Vol 151 (10) ◽  
pp. 3287-3298 ◽  
Author(s):  
Caroline Blumer ◽  
Alexandra Kleefeld ◽  
Daniela Lehnen ◽  
Margit Heintz ◽  
Ulrich Dobrindt ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Invertible Element ◽  
Transcriptional Regulator ◽  
Host Cells ◽  
Yeast Cells ◽  
Type 1 Fimbriae ◽  
Biofilm Development

Type 1 fimbriae of Escherichia coli facilitate attachment to the host mucosa and promote biofilm formation on abiotic surfaces. The transcriptional regulator LrhA, which is known as a repressor of flagellar, motility and chemotaxis genes, regulates biofilm formation and expression of type 1 fimbriae. Whole-genome expression profiling revealed that inactivation of lrhA results in an increased expression of structural components of type 1 fimbriae. In vitro, LrhA bound to the promoter regions of the two fim recombinases (FimB and FimE) that catalyse the inversion of the fimA promoter, and to the invertible element itself. Translational lacZ fusions with these genes and quantification of fimE transcript levels by real-time PCR showed that LrhA influences type 1 fimbrial phase variation, primarily via activation of FimE, which is required for the ON-to-OFF transition of the fim switch. Enhanced type 1 fimbrial expression as a result of lrhA disruption was confirmed by mannose-sensitive agglutination of yeast cells. Biofilm formation was stimulated by lrhA inactivation and completely suppressed upon LrhA overproduction. The effects of LrhA on biofilm formation were exerted via the changed levels of surface molecules, most probably both flagella and type 1 fimbriae. Together, the data show a role for LrhA as a repressor of type 1 fimbrial expression, and thus as a regulator of the initial stages of biofilm development and, presumably, bacterial adherence to epithelial host cells also.

scholarly journals The Transcriptional Regulator Nrg1p Controls Candida albicans Biofilm Formation and Dispersion

2010 ◽  
Vol 9 (10) ◽  
pp. 1531-1537 ◽  
Author(s):  
Priya Uppuluri ◽  
Christopher G. Pierce ◽  
Derek P. Thomas ◽  
Sarah S. Bubeck ◽  
Stephen P. Saville ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Structural Integrity ◽  
Genetically Engineered ◽  
Negative Regulator ◽  
Yeast Cells ◽  
Developmental Cycle ◽  
Content Type ◽  
Adhesive Interactions

ABSTRACT The ability of Candida albicans to reversibly switch morphologies is important for biofilm formation and dispersion. In this pathogen, Nrg1p functions as a key negative regulator of the yeast-to-hypha morphogenetic transition. We have previously described a genetically engineered C. albicans tet-NRG1 strain in which NRG1 expression levels can be manipulated by the presence or absence of doxycycline (DOX). Here, we have used this strain to ascertain the role of Nrg1p in regulating the different stages of the C. albicans biofilm developmental cycle. In an in vitro model of biofilm formation, the C. albicans tet-NRG1 strain was able to form mature biofilms only when DOX was present in the medium, but not in the absence of DOX, when high levels of NRG1 expression blocked the yeast-to-hypha transition. However, in a biofilm cell retention assay in which biofilms were developed with mixtures of C. albicans tet-NRG1 and SC5314 strains, tet-NRG1 yeast cells were still incorporated into the mixed biofilms, in which an intricate network of hyphae of the wild-type strain provided for biofilm structural integrity and adhesive interactions. Also, utilizing an in vitro biofilm model under conditions of flow, we demonstrated that C. albicans Nrg1p exerts an exquisite control of the dispersal process, as overexpression of NRG1 leads to increases in dispersion of yeast cells from the biofilms. Our results demonstrate that manipulation of NRG1 gene expression has a profound influence on biofilm formation and biofilm dispersal, thus identifying Nrg1p as a key regulator of the C. albicans biofilm life cycle.

scholarly journals Heterogeneous distribution of Candida albicans cell-surface antigens demonstrated with an Als1-specific monoclonal antibody

Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3645-3659 ◽  
Author(s):  
David A. Coleman ◽  
Soon-Hwan Oh ◽  
Xiaomin Zhao ◽  
Lois L. Hoyer
Keyword(s):  
Candida Albicans ◽  
Cell Surface ◽  
Spatial Localization ◽  
Host Cells ◽  
Yeast Cells ◽  
Cell Surface Antigens ◽  
Heterogeneous Distribution ◽  
Germ Tubes

Despite an abundance of data describing expression of genes in the Candida albicans ALS (agglutinin-like sequence) gene family, little is known about the production of Als proteins on individual cells, their spatial localization or stability. Als proteins are most commonly discussed with respect to function in adhesion of C. albicans to host and abiotic surfaces. Development of a mAb specific for Als1, one of the eight large glycoproteins encoded by the ALS family, provided the opportunity to detect Als1 during growth of yeast and hyphae, both in vitro and in vivo, and to demonstrate the utility of the mAb in blocking C. albicans adhesion to host cells. Although most C. albicans yeast cells in a saturated culture are Als1-negative by indirect immunofluorescence, Als1 is detected on the surface of nearly all cells shortly after transfer into fresh growth medium. Als1 covers the yeast cell surface, with the exception of bud scars. Daughters of the inoculum cells, and sometimes granddaughters, also have detectable Als1, but Als1 is not detectable on cells from subsequent generations. On germ tubes and hyphae, most Als1 is localized proximal to the mother yeast. Once deposited on yeasts or hyphae, Als1 persists long after the culture has reached saturation. Growth stage-dependent production of Als1, coupled with its persistence on the cell surface, results in a heterogeneous population of cells within a C. albicans culture. Anti-Als1 immunolabelling patterns vary depending on the source of the C. albicans cells, with obvious differences between cells recovered from culture and those from a murine model of disseminated candidiasis. Results from this work highlight the temporal parallels for ALS1 expression and Als1 production in yeasts and germ tubes, the specialized spatial localization and persistence of Als1 on the C. albicans cell surface, and the differences in Als1 localization that occur in vitro and in vivo.

scholarly journals Candida albicansDispersed Cells Are Developmentally Distinct from Biofilm and Planktonic Cells

mBio ◽  
2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Priya Uppuluri ◽  
Maikel Acosta Zaldívar ◽  
Matthew Z. Anderson ◽  
Matthew J. Dunn ◽  
Judith Berman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Carbon Sources ◽  
Yeast Cells ◽  
Direct Access ◽  
Molecular Characteristics ◽  
Content Type ◽  
Biofilm Dispersal ◽  
Biofilm Development ◽  
Dispersed Cells

ABSTRACTCandida albicanssurface-attached biofilms such as those formed on intravenous catheters with direct access to the bloodstream often serve as a nidus for continuous release of cells capable of initiating new infectious foci. We previously reported that cells dispersed from a biofilm are yeast cells that originate from the top-most hyphal layers of the biofilm. Compared to their planktonic counterparts, these biofilm dispersal yeast cells displayed enhanced virulence-associated characteristics and drug resistance. However, little is known about their molecular properties. To address that issue, in this study we aimed to define the molecular characteristics of these biofilm dispersal cells. We found that the inducer of dispersal,PES1, genetically interacts with the repressor of filamentation,NRG1, in a manner consistent with the definition of dispersed cells as yeast cells. Further, using a flow biofilm model, we performed comprehensive comparative RNA sequencing on freshly dispersed cells in order to identify unique transcriptomic characteristics. Gene expression analysis demonstrated that dispersed cells largely inherit a biofilm-like mRNA profile. Strikingly, however, dispersed cells seemed transcriptionally reprogrammed to acquire nutrients such as zinc and amino acids and to metabolize alternative carbon sources, while their biofilm-associated parent cells did not induce the same high-affinity transporters or express gluconeogenetic genes, despite exposure to the same nutritional signals. Collectively, the findings from this study characterize cell dispersal as an intrinsic step of biofilm development which generates propagules more adept at colonizing distant host sites. This developmental step anticipates the need for virulence-associated gene expression before the cells experience the associated external signals.IMPORTANCECandida albicanssurface-attached biofilms serve as a reservoir of cells to perpetuate and expand an infection; cells released from biofilms on catheters have direct access to the bloodstream. Biofilm dispersal yeast cells exhibit enhanced adhesion, invasion, and biofilm formation compared to their planktonic counterparts. Here, we show using transcriptome sequencing (RNA-seq) that dispersed yeast cells are developmentally distinct from the cells in their parent biofilms as well as from planktonic yeast cells. Dispersal cells possess an anticipatory expression pattern that primes them to infect new sites in the host, to survive in nutrient-starved niches, and to invade new sites. These studies identified dispersal cells as a unique proliferative cell type of the biofilm and showed that they could serve as targets for antibiofilm drug development in the future.

scholarly journals Plasticity of Candida albicans Biofilms

2016 ◽  
Vol 80 (3) ◽  
pp. 565-595 ◽  
Author(s):  
David R. Soll ◽  
Karla J. Daniels
Keyword(s):  
Extracellular Matrix ◽  
Candida Albicans ◽  
Fungal Pathogen ◽  
Biofilm Formation ◽  
Strain Differences ◽  
Type Locus ◽  
Content Type ◽  
Biofilm Development ◽  
Candida Albicans Biofilms

SUMMARYCandida 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 formedin vitrovary 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 theMTLlocus. 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.

scholarly journals Treatment with Candida albicans biotherapic influences in vitro fungal adhesion to Ma-104 cells

2021 ◽  
Vol 10 (36) ◽  
pp. 152-154
Author(s):  
Beatriz Guerreiro Basílio Costa ◽  
Camila Monteiro Siqueira ◽  
Gleyce Moreno Barbosa ◽  
Venicio Feo Da Veiga ◽  
Maristela Barbosa Portela ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Oral Candidiasis ◽  
Fungal Growth ◽  
Host Cells ◽  
Yeast Cells ◽  
Distilled Water ◽  
Candida Spp ◽  
Morphological Alterations ◽  
Morphological Aspects

Background: Oral candidiasis is an opportunist fungal infection in humans, mainly caused by Candida albicans. It occurs when the host presents an imbalance in the immune system and Candida spp., normally found in human flora, become able to develop the infection [1]. This disease is very common in HIV patients, and in all individuals that present immunossupression, such as patients treated with chemotherapy. Considering this scenario, the development of new medicines to treat oral candidiasis is mandatory. Aims: The aim of this study was to evaluate citotoxicity, morphology and quantify the adhesion rates of C. albicans to biotherapic-treated Ma104 cells. Methodology: The biotherapic was prepared following the Roberto Costa technique and Brazilian Homeopathic Pharmacopeia protocol [2]. Briefly, biotherapic 1X was prepared with 1 mL of aqueous solution containing 108 yeasts of living Candida albicans plus 9 ml of sterile distilled water. This solution was submmited to 100 mechanical succussions. Biotherapic 2X was obtained after addition of 1 ml of 1X solution in 9 ml of sterile distilled water and it was also submitted to 100 mechanical succussions. This procedure was repeated until biotherapic 30X was obtained. As a control, sterile dynamized water (30X) was used. The inhibition of fungal growth induced by biotherapic was evaluated by MTT method after 24 hours of treatment. The morphological aspects of Ma104-biotherapic-treated cells were analyzed by Giemsa staining after 5, 10 and 60 days, and compared with control groups (water 30X and untreated cells). Additionally, Ma104 cells were treated during 5 and 30 days with biotherapic in parallel with respective controls, and the index adhesion of yeast cells was quantified. Results: The biotherapic was not able to reduce the viability of treated C. albicans when compared with controls. On the other hand, Ma104 treated cells presented important morphological alterations after 60 days, such as: cytoplasmic vacuoles, halos around the nucleolus and elongation of the plasmatic membrane. These changes were not observed in ,untreated cells nor in ones treated with water 30X. The adhesion index to Ma104 cells was reduced around 27% after 5 and 30 days of treatment when compared to controls. Conclusion: These results showed that the biotherapic did not present any citotoxicity, but was able to modify the morphological aspects of Ma-104 cells. Additionally, the interaction between host cells and ethilogic agent is directly influenced by biotherapic treatment, suggesting a promising antifungal potential of this medicine.

Sign in / Sign up

Export Citation Format

Share Document