scholarly journals Eap1p, an Adhesin That Mediates Candida albicans Biofilm Formation In Vitro and In Vivo

2007 ◽  
Vol 6 (6) ◽  
pp. 931-939 ◽  
Author(s):  
Fang Li ◽  
Michael J. Svarovsky ◽  
Amy J. Karlsson ◽  
Joel P. Wagner ◽  
Karen Marchillo ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Cell Adhesion ◽  
Biofilm Formation ◽  
Fungal Infections ◽  
Gene Dosage ◽  
Venous Catheter ◽  
Flow Chamber ◽  
Dependent Manner

ABSTRACT Candida albicans is the leading cause of systemic fungal infections in immunocompromised humans. The ability to form biofilms on surfaces in the host or on implanted medical devices enhances C. albicans virulence, leading to antimicrobial resistance and providing a reservoir for infection. Biofilm formation is a complex multicellular process consisting of cell adhesion, cell growth, morphogenic switching between yeast form and filamentous states, and quorum sensing. Here we describe the role of the C. albicans EAP1 gene, which encodes a glycosylphosphatidylinositol-anchored, glucan-cross-linked cell wall protein, in adhesion and biofilm formation in vitro and in vivo. Deleting EAP1 reduced cell adhesion to polystyrene and epithelial cells in a gene dosage-dependent manner. Furthermore, EAP1 expression was required for C. albicans biofilm formation in an in vitro parallel plate flow chamber model and in an in vivo rat central venous catheter model. EAP1 expression was upregulated in biofilm-associated cells in vitro and in vivo. Our results illustrate an association between Eap1p-mediated adhesion and biofilm formation in vitro and in vivo.

scholarly journals Targeting Fibronectin To Disrupt In Vivo Candida albicans Biofilms

2016 ◽  
Vol 60 (5) ◽  
pp. 3152-3155 ◽  
Author(s):  
Jeniel E. Nett ◽  
Jonathan Cabezas-Olcoz ◽  
Karen Marchillo ◽  
Deane F. Mosher ◽  
David R. Andes
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Drug Targets ◽  
Venous Catheter ◽  
Surface Adhesion ◽  
Inhibitory Protein ◽  
Content Type ◽  
Novel Target

ABSTRACTNew drug targets are of great interest for the treatment of fungal biofilms, which are routinely resistant to antifungal therapies. We theorized that the interaction ofCandida albicanswith matricellular host proteins would provide a novel target. Here, we show that an inhibitory protein (FUD) targetingCandida-fibronectin interactions disrupts biofilm formationin vitroandin vivoin a rat venous catheter model. The peptide appears to act by blocking the surface adhesion ofCandida, halting biofilm formation.

scholarly journals Function of Candida albicans Adhesin Hwp1 in Biofilm Formation

2006 ◽  
Vol 5 (10) ◽  
pp. 1604-1610 ◽  
Author(s):  
Clarissa J. Nobile ◽  
Jeniel E. Nett ◽  
David R. Andes ◽  
Aaron P. Mitchell
Keyword(s):  
Candida Albicans ◽  
Cell Surface ◽  
Biofilm Formation ◽  
Tight Binding ◽  
Surface Protein ◽  
Venous Catheter ◽  
Cell Surface Protein ◽  
Additional Support

ABSTRACT Hwp1 is a well-characterized Candida albicans cell surface protein, expressed only on hyphae, that mediates tight binding to oral epithelial cells. Prior studies indicate that HWP1 expression is dependent upon Bcr1, a key regulator of biofilm formation. Here we test the hypothesis that Hwp1 is required for biofilm formation. In an in vitro model, the hwp1/hwp1 mutant produces a thin biofilm that lacks much of the hyphal mass found in the hwp1/HWP1 reconstituted strain. In a biofilm cell retention assay, we find that the hwp1/hwp1 mutant is defective in retention of nonadherent bcr1/bcr1 mutant cells. In an in vivo rat venous catheter model, the hwp1/hwp1 mutant has a severe biofilm defect, yielding only yeast microcolonies in the catheter lumen. These properties of the hwp1/hwp1 mutant are consistent with its role as a hypha-specific adhesin and indicate that it is required for normal biofilm formation. Overexpression of HWP1 in a bcr1/bcr1 mutant background improves adherence in the in vivo catheter model. This finding provides additional support for the model that Hwp1 is critical for biofilm adhesion. Hwp1 is the first cell surface protein known to be required for C. albicans biofilm formation in vivo and is thus an excellent therapeutic target.

scholarly journals Acetylcholine Protects against Candida albicans Infection by Inhibiting Biofilm Formation and Promoting Hemocyte Function in a Galleria mellonella Infection Model

2015 ◽  
Vol 14 (8) ◽  
pp. 834-844 ◽  
Author(s):  
Ranjith Rajendran ◽  
Elisa Borghi ◽  
Monica Falleni ◽  
Federica Perdoni ◽  
Delfina Tosi ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Galleria Mellonella ◽  
Inflammatory Responses ◽  
Fungal Infections ◽  
Infection Model ◽  
Content Type

ABSTRACT Both neuronal acetylcholine and nonneuronal acetylcholine have been demonstrated to modulate inflammatory responses. Studies investigating the role of acetylcholine in the pathogenesis of bacterial infections have revealed contradictory findings with regard to disease outcome. At present, the role of acetylcholine in the pathogenesis of fungal infections is unknown. Therefore, the aim of this study was to determine whether acetylcholine plays a role in fungal biofilm formation and the pathogenesis of Candida albicans infection. The effect of acetylcholine on C. albicans biofilm formation and metabolism in vitro was assessed using a crystal violet assay and phenotypic microarray analysis. Its effect on the outcome of a C. albicans infection, fungal burden, and biofilm formation were investigated in vivo using a Galleria mellonella infection model. In addition, its effect on modulation of host immunity to C. albicans infection was also determined in vivo using hemocyte counts, cytospin analysis, larval histology, lysozyme assays, hemolytic assays, and real-time PCR. Acetylcholine was shown to have the ability to inhibit C. albicans biofilm formation in vitro and in vivo . In addition, acetylcholine protected G. mellonella larvae from C. albicans infection mortality. The in vivo protection occurred through acetylcholine enhancing the function of hemocytes while at the same time inhibiting C. albicans biofilm formation. Furthermore, acetylcholine also inhibited inflammation-induced damage to internal organs. This is the first demonstration of a role for acetylcholine in protection against fungal infections, in addition to being the first report that this molecule can inhibit C. albicans biofilm formation. Therefore, acetylcholine has the capacity to modulate complex host-fungal interactions and plays a role in dictating the pathogenesis of fungal infections.

scholarly journals Global Identification of Biofilm-Specific Proteolysis in Candida albicans

mBio ◽  
2016 ◽  
Vol 7 (5) ◽  
Author(s):  
Michael B. Winter ◽  
Eugenia C. Salcedo ◽  
Matthew B. Lohse ◽  
Nairi Hartooni ◽  
Megha Gulati ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Venous Catheter ◽  
Opportunistic Pathogen ◽  
Fungal Species ◽  
Implanted Medical Devices ◽  
Opportunistic Fungal Pathogen ◽  
Biofilm Development

ABSTRACT Candida albicans is a fungal species that is part of the normal human microbiota and also an opportunistic pathogen capable of causing mucosal and systemic infections. C. albicans cells proliferate in a planktonic (suspension) state, but they also form biofilms, organized and tightly packed communities of cells attached to a solid surface. Biofilms colonize many niches of the human body and persist on implanted medical devices, where they are a major source of new C. albicans infections. Here, we used an unbiased and global substrate-profiling approach to discover proteolytic activities produced specifically by C. albicans biofilms, compared to planktonic cells, with the goal of identifying potential biofilm-specific diagnostic markers and targets for therapeutic intervention. This activity-based profiling approach, coupled with proteomics, identified Sap5 (Candidapepsin-5) and Sap6 (Candidapepsin-6) as major biofilm-specific proteases secreted by C. albicans . Fluorogenic peptide substrates with selectivity for Sap5 or Sap6 confirmed that their activities are highly upregulated in C. albicans biofilms; we also show that these activities are upregulated in other Candida clade pathogens. Deletion of the SAP5 and SAP6 genes in C. albicans compromised biofilm development in vitro in standard biofilm assays and in vivo in a rat central venous catheter biofilm model. This work establishes secreted proteolysis as a promising enzymatic marker and potential therapeutic target for Candida biofilm formation. IMPORTANCE Biofilm formation by the opportunistic fungal pathogen C. albicans is a major cause of life-threatening infections. This work provides a global characterization of secreted proteolytic activity produced specifically by C. albicans biofilms. We identify activity from the proteases Sap5 and Sap6 as highly upregulated during C. albicans biofilm formation and develop Sap-cleavable fluorogenic substrates that enable the detection of biofilms from C. albicans and also from additional pathogenic Candida species. Furthermore, SAP5 and SAP6 deletions confirm that both proteases are required for proper biofilm development in vitro and in vivo . We propose that secreted proteolysis is a promising marker for the diagnosis and potential therapeutic targeting of Candida biofilm-associated infections.

scholarly journals In VitroAnalyses of the Effects of Heparin and Parabens on Candida albicans Biofilms and Planktonic Cells

2011 ◽  
Vol 56 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Marisa H. Miceli ◽  
Stella M. Bernardo ◽  
T. S. Neil Ku ◽  
Carla Walraven ◽  
Samuel A. Lee
Keyword(s):  
Candida Albicans ◽  
Metabolic Activity ◽  
Biofilm Formation ◽  
High Dose ◽  
Dependent Manner ◽  
Planktonic Cells ◽  
Content Type ◽  
Heparin Sodium ◽  
The Individual

ABSTRACTInfections and thromboses are the most common complications associated with central venous catheters. Suggested strategies for prevention and management of these complications include the use of heparin-coated catheters, heparin locks, and antimicrobial lock therapy. However, the effects of heparin onCandida albicansbiofilms and planktonic cells have not been previously studied. Therefore, we sought to determine thein vitroeffect of a heparin sodium preparation (HP) on biofilms and planktonic cells ofC. albicans. Because HP contains two preservatives, methyl paraben (MP) and propyl paraben (PP), these compounds and heparin sodium without preservatives (Pure-H) were also tested individually. The metabolic activity of the mature biofilm after treatment was assessed using XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and microscopy. Pure-H, MP, and PP caused up to 75, 85, and 60% reductions of metabolic activity of the mature preformedC. albicansbiofilms, respectively. Maximal efficacy against the mature biofilm was observed with HP (up to 90%) compared to the individual compounds (P< 0.0001). Pure-H, MP, and PP each inhibitedC. albicansbiofilm formation up to 90%. A complete inhibition of biofilm formation was observed with HP at 5,000 U/ml and higher. When tested against planktonic cells, each compound inhibited growth in a dose-dependent manner. These data indicated that HP, MP, PP, and Pure-H havein vitroantifungal activity againstC. albicansmature biofilms, formation of biofilms, and planktonic cells. Investigation of high-dose heparin-based strategies (e.g., heparin locks) in combination with traditional antifungal agents for the treatment and/or prevention ofC. albicansbiofilms is warranted.

Effect of Single Dose In Vivo Propranolol Therapy on In Vitro Adhesion of Human SS RBC.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1234-1234 ◽  
Author(s):  
Laura M. De Castro ◽  
Jude C. Jonassaint ◽  
Jennifer G. Johnson ◽  
Milena Batchvarova ◽  
Marilyn J. Telen
Keyword(s):  
Safety Data ◽  
Study Drug ◽  
Flow Chamber ◽  
In Vivo Studies ◽  
Dependent Manner ◽  
Number Of Patients ◽  
Significant Difference ◽  
Before And After

Abstract Sickle red blood cells (SS RBC) are abnormally adhesive to both endothelial cells (ECs) and components of the extracellular matrix (ECM). Epinephrine (epi) has been shown to elevate cAMP in SS RBC and increase adhesion of SS RBC to ECs in a protein kinase A-dependent manner. In vitro and in vivo studies performed in our lab have led to the hypothesis that adrenergic stimuli such as epi may initiate or exacerbate vaso-occlusion and thus contribute to the association of vaso-occlusive events with physiologic stress. We are conducting a prospective, dose-escalation pilot clinical study to investigate whether in vivo administration of one dose of propranolol either down-regulates baseline SS RBC adhesion in vitro or prevents its upregulation by epi. In addition, this study will provide additional safety data regarding the use of propranolol in normotensive patients with sickle cell disease (SCD). Figure Figure To date, we have completed the first two dose cohorts. 11 subjects (9 SS and 1 Sβ° thalassemia; 7 females, 3 males) have participated. No severe adverse events were noted. Cohorts 1 and 2 had mean pre-propranolol blood pressure (BP) of 116 (5.9 SD)/ 60.4 (3.98 SD) and 106.8 (4.68 SD)/ 58 (3.9 SD), respectively; this difference was not statistically significant. Minimal and asymptomatic changes in BP were noted in both cohorts after drug administration, with biphasic systolic and diastolic BP nadirs at 45 and 240 minutes. No clinically significant changes in heart rate were observed. Adhesion studies were performed using a graduated height flow chamber on the day of RBC collection. RBC adhesion to ECs was studied before and after epi stimulation and was measured at sheer stresses ranging from 1 to 3 dyne/cm2. Baseline adhesion measurements were validated by comparing percent (%) adhesion assayed at 2 different times within 7 days—at screening and before propranolol dose on the study drug day. We observed no significant difference in adhesion at the 2 different time points without propranolol. Comparison of % adhesion of epi-stimulated RBC to ECs before and 1 hour after propranolol showed that propranolol given in vivo significantly inhibited both non-stimulated and epi-stimulated SS RBC adhesion (p=0.04 and p=0.001, respectively). Lastly, comparison of SS RBC adhesion at both drug doses confirmed the drug-related inhibition of adhesion (p&lt;0.004). We conclude that propranolol administered in vivo decreases SS RBC baseline adhesion to ECs and substantially abrogates epi-stimulated adhesion to ECs, as measured in vitro. Although we have thus far studied only a small number of patients and low propranolol doses, we expect to confirm these results with the 3rd cohort, in which a higher dose of propranolol will be used. If our findings continue to show that propranolol can decrease both SS RBC baseline and epi-stimulated adhesion to ECs, study of propranolol on a larger scale would be warranted in order to ascertain its safety and efficacy as an anti-adhesive therapy in SCD.

scholarly journals Reduced Virulence of HWP1-Deficient Mutants of Candida albicans and Their Interactions with Host Cells

2000 ◽  
Vol 68 (4) ◽  
pp. 1997-2002 ◽  
Author(s):  
Noboru Tsuchimori ◽  
Laura L. Sharkey ◽  
William A. Fonzi ◽  
Samuel W. French ◽  
John E. Edwards ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Cell Injury ◽  
Gene Dosage ◽  
Surface Protein ◽  
Host Cells ◽  
Null Mutant ◽  
Gene Dosage Effect ◽  
Hyphal Development

ABSTRACT The Candida albicans gene HWP1 encodes a surface protein that is required for normal hyphal development in vitro. We used mutants lacking one or both alleles of HWP1to investigate the role of this gene in virulence. Mice infected intravenously with the homozygous hwp1 null mutant, CAL3, survived a median of >14 days, whereas mice infected with a control strain containing two functional alleles of HWP1 survived only 3.5 days. After 1 day of infection, all strains produced similar levels of infection in the kidneys, spleen, and blood. However, after 2 and 3 days, there was a significant decrease in the number of organisms in the kidneys of the mice infected with CAL3. This finding suggests that the hwp1 homozygous null mutant is normal in its ability to initiate infection but deficient in its capacity to maintain infection. CAL3 also germinated minimally in the kidneys. The ability of the heterozygous null mutant to germinate and cause mortality in mice was intermediate to CAL3, suggesting a gene dosage effect. To investigate potential mechanisms for the diminished virulence of CAL3, we examined its interactions with endothelial cells and neutrophils in vitro. CAL3 caused less endothelial cell injury than the heterozygoushwp1 mutant. We conclude that the HWP1 gene product is important for both in vivo hyphal development and pathogenicity of C. albicans. Also, the ability to form filaments may be critical for candidal virulence by enabling the fungus to induce cellular injury and maintain a deep-seated infection.

scholarly journals Oral Administration of the Broad-Spectrum Antibiofilm Compound Toremifene Inhibits Candida albicans and Staphylococcus aureus Biofilm FormationIn Vivo

2014 ◽  
Vol 58 (12) ◽  
pp. 7606-7610 ◽  
Author(s):  
Kaat De Cremer ◽  
Nicolas Delattin ◽  
Katrijn De Brucker ◽  
Annelies Peeters ◽  
Soña Kucharíková ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Broad Spectrum ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Candida Krusei ◽  
Content Type ◽  
And Staphylococcus Aureus

ABSTRACTWe here report on thein vitroactivity of toremifene to inhibit biofilm formation of different fungal and bacterial pathogens, includingCandida albicans,Candida glabrata,Candida dubliniensis,Candida krusei,Pseudomonas aeruginosa,Staphylococcus aureus, andStaphylococcus epidermidis. We validated thein vivoefficacy of orally administered toremifene againstC. albicans and S. aureusbiofilm formation in a rat subcutaneous catheter model. Combined, our results demonstrate the potential of toremifene as a broad-spectrum oral antibiofilm compound.

scholarly journals Intravital Imaging of Candida albicans Identifies Differential In Vitro and In Vivo Filamentation Phenotypes for Transcription Factor Deletion Mutants

mSphere ◽  
2021 ◽  
Author(s):  
Rohan S. Wakade ◽  
Manning Huang ◽  
Aaron P. Mitchell ◽  
Melanie Wellington ◽  
Damian J. Krysan
Keyword(s):  
Candida Albicans ◽  
Fungal Infections ◽  
Deletion Mutants ◽  
Filamentous Form ◽  
Content Type ◽  
Yeast Form ◽  
Common Causes ◽  
Do So

Candida albicans is one of the most common causes of fungal infections in humans. C. albicans undergoes a transition from a round yeast form to a filamentous form during infection, which is critical for its ability to cause disease. Although this transition has been studied in the laboratory for years, methods to do so in an animal model of infection have been limited.

scholarly journals Effects of Hsp90 Inhibitor Ganetespib on Inhibition of Azole-Resistant Candida albicans

2021 ◽  
Vol 12 ◽  
Author(s):  
Rui Yuan ◽  
Jie Tu ◽  
Chunquan Sheng ◽  
Xi Chen ◽  
Na Liu
Keyword(s):  
Drug Resistance ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Inhibitory Effect ◽  
Hsp90 Inhibitor ◽  
Pcr Analysis ◽  
Fungal Hypha

Candida albicans is the most common fungal pathogen. Recently, drug resistance of C. albicans is increasingly severe. Hsp90 is a promising antifungal target to overcome this problem. To evaluate the effects of Hsp90 inhibitor ganetespib on the inhibition of azole-resistant C. albicans, the microdilution checkerboard method was used to measure the in vitro synergistic efficacy of ganetespib. The XTT/menadione reduction assay, microscopic observation, and Rh6G efflux assay were established to investigate the effects of ganetespib on azole-resistant C. albicans biofilm formation, filamentation, and efflux pump. Real-time RT-PCR analysis was employed to clarify the mechanism of antagonizing drug resistance. The in vivo antifungal efficacy of ganetespib was determined by the infectious model of azole-resistant C. albicans. Ganetespib showed an excellent synergistic antifungal activity in vitro and significantly inhibited the fungal biofilm formation, whereas it had no inhibitory effect on fungal hypha formation. Expression of azole-targeting enzyme gene ERG11 and efflux pump genes CDR1, CDR2, and MDR1 was significantly down-regulated when ganetespib was used in combination with FLC. In a mouse model infected with FLC-resistant C. albicans, the combination of ganetespib and FLC effectively reversed the FLC resistance and significantly decreased the kidney fungal load of mouse.

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