scholarly journals Alcohol Dehydrogenase Restricts the Ability of the Pathogen Candida albicans To Form a Biofilm on Catheter Surfaces through an Ethanol-Based Mechanism

2006 ◽  
Vol 74 (7) ◽  
pp. 3804-3816 ◽  
Author(s):  
Pranab K. Mukherjee ◽  
Sotohy Mohamed ◽  
Jyotsna Chandra ◽  
Duncan Kuhn ◽  
Shuqing Liu ◽  
...  

ABSTRACT Candida biofilms formed on indwelling medical devices are increasingly associated with severe infections. In this study, we used proteomics and Western and Northern blotting analyses to demonstrate that alcohol dehydrogenase (ADH) is downregulated in Candida biofilms. Disruption of ADH1 significantly (P = 0.0046) enhanced the ability of Candida albicans to form biofilm. Confocal scanning laser microscopy showed that the adh1 mutant formed thicker biofilm than the parent strain (210 μm and 140 μm, respectively). These observations were extended to an engineered human oral mucosa and an in vivo rat model of catheter-associated biofilm. Inhibition of Candida ADH enzyme using disulfiram and 4-methylpyrazole resulted in thicker biofilm (P < 0.05). Moreover, biofilms formed by the adh1 mutant strain produced significantly smaller amounts of ethanol, but larger amounts of acetaldehyde, than biofilms formed by the parent and revertant strains (P < 0.0001), demonstrating that the effect of Adh1p on biofilm formation is mediated by its enzymatic activity. Furthermore, we found that 10% ethanol significantly inhibited biofilm formation in vitro, with complete inhibition of biofilm formation at ethanol concentrations of ≥20%. Similarly, using a clinically relevant rabbit model of catheter-associated biofilm, we found that ethanol treatment inhibited biofilm formation by C. albicans in vivo (P < 0.05) but not by Staphylococcus spp. (P > 0.05), indicating that ethanol specifically inhibits Candida biofilm formation. Taken together, our studies revealed that Adh1p contributes to the ability of C. albicans to form biofilms in vitro and in vivo and that the protein restricts biofilm formation through an ethanol-dependent mechanism. These results are clinically relevant and may suggest novel antibiofilm treatment strategies.

2007 ◽  
Vol 6 (6) ◽  
pp. 931-939 ◽  
Author(s):  
Fang Li ◽  
Michael J. Svarovsky ◽  
Amy J. Karlsson ◽  
Joel P. Wagner ◽  
Karen Marchillo ◽  
...  

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.


2001 ◽  
Vol 45 (2) ◽  
pp. 485-494 ◽  
Author(s):  
Arnold Louie ◽  
Pamela Kaw ◽  
Partha Banerjee ◽  
Weiguo Liu ◽  
George Chen ◽  
...  

ABSTRACT In vitro time-kill studies and a rabbit model of endocarditis and pyelonephritis were used to define the impact that the order of exposure of Candida albicans to fluconazole (FLC) and amphotericin B (AMB), as sequential and combination therapies, had on the susceptibility of C. albicans to AMB and on the outcome. The contribution of FLC-induced resistance to AMB for C. albicans also was assessed. In vitro, AMB monotherapy rapidly killed each of four C. albicans strains; FLC alone was fungistatic. Preincubation of these fungi with FLC for 18 h prior to exposure to AMB decreased their susceptibilities to AMB for 8 to >40 h. Induced resistance to AMB was transient, but the duration of resistance increased with the length of FLC preincubation. Yeast sequentially incubated with FLC followed by AMB plus FLC (FLC→AMB+FLC) showed fungistatic growth kinetics similar to that of fungi that were exposed to FLC alone. This antagonistic effect persisted for at least 24 h. Simultaneous exposure of C. albicans to AMB and FLC [AMB+FLC(simult)] demonstrated activity similar to that with AMB alone for AMB concentrations of ≥1 μg/ml; antagonism was seen using an AMB concentration of 0.5 μg/ml. The in vitro findings accurately predicted outcomes in our rabbit infection model. In vivo, AMB monotherapy and treatment with AMB for 24 h followed by AMB plus FLC (AMB→AMB+FLC) rapidly sterilized kidneys and cardiac vegetations. AMB+FLC(simult) and FLC→AMB treatments were slower in clearing fungi from infected tissues. FLC monotherapy and FLC→AMB+FLC were both fungistatic and were the least active regimens. No adverse interaction was observed between AMB and FLC for the AMB→FLC regimen. However, FLC→AMB treatment was slower than AMB alone in clearing fungi from tissues. Thus, our in vitro and in vivo studies both demonstrate that preexposure of C. albicans to FLC reduces fungal susceptibility to AMB. The length of FLC preexposure and whether AMB is subsequently used alone or in combination with FLC determine the duration of induced resistance to AMB.


2016 ◽  
Vol 60 (5) ◽  
pp. 3152-3155 ◽  
Author(s):  
Jeniel E. Nett ◽  
Jonathan Cabezas-Olcoz ◽  
Karen Marchillo ◽  
Deane F. Mosher ◽  
David R. Andes

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.


2004 ◽  
Vol 48 (8) ◽  
pp. 3051-3056 ◽  
Author(s):  
Michael R. Yeaman ◽  
Darwin Cheng ◽  
Bhavesh Desai ◽  
Leon I. Kupferwasser ◽  
Yan-Qiong Xiong ◽  
...  

ABSTRACT Platelet microbicidal proteins (PMPs) are believed to be integral to host defense against endovascular infection. We previously demonstrated that susceptibility to thrombin-induced PMP 1 (tPMP-1) in vitro negatively influences Candida albicans virulence in the rabbit model of infective endocarditis (IE). This study evaluated the relationship between in vitro tPMP-1 susceptibility (tPMP-1s) or resistance (tPMP-1r) and efficacy of fluconazole (FLU) therapy of IE due to C. albicans. Candida IE was established in rabbits with either tPMP-1s or tPMP-1r strains. Treatment groups received FLU (100 mg/kg/day) intraperitoneally for 7 or 14 days; control animals received no therapy. At these time points, cardiac vegetations, kidneys, and spleens were quantitatively cultured to assess fungal burden. At both 7 and 14 days and in all target tissues, the extent of candidal clearance by FLU was greater in animals infected with the tPMP-1s strain than in those infected with the tPMP-1r strain. These differences were statistically significant in the spleen and kidney. Corroborating these in vivo data, FLU (a candidastatic agent), in combination with tPMP-1, exerted an enhanced fungicidal effect in vitro against tPMP-1s and tPMP-1r C. albicans, with the extent of this effect greatest against the tPMP-1s strain. Collectively, these results support the concept that tPMP-1 susceptibility contributes to the net efficacy of FLU against C. albicans IE in vivo, particularly in tissues in which platelets and tPMP-1 likely play significant roles in host defense.


2014 ◽  
Vol 58 (12) ◽  
pp. 7606-7610 ◽  
Author(s):  
Kaat De Cremer ◽  
Nicolas Delattin ◽  
Katrijn De Brucker ◽  
Annelies Peeters ◽  
Soña Kucharíková ◽  
...  

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.


2021 ◽  
Vol 12 ◽  
Author(s):  
Rui Yuan ◽  
Jie Tu ◽  
Chunquan Sheng ◽  
Xi Chen ◽  
Na Liu

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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Aitziber Antoran ◽  
Leire Aparicio-Fernandez ◽  
Aize Pellon ◽  
Idoia Buldain ◽  
Leire Martin-Souto ◽  
...  

2019 ◽  
Vol 7 (2) ◽  
pp. 42 ◽  
Author(s):  
Yosi Farkash ◽  
Mark Feldman ◽  
Isaac Ginsburg ◽  
Doron Steinberg ◽  
Miriam Shalish

Background: Streptococcus mutans (S. mutans) and Candida albicans (C. albicans) are two major contributors to dental caries. They have a symbiotic relationship, allowing them to create an enhanced biofilm. Our goal was to examine whether two natural polyphenols (Padma hepaten (PH) and a polyphenol extraction from green tea (PPFGT)) could inhibit the caries-inducing properties of S. mutans and C. albicans. Methods: Co-species biofilms of S. mutans and C. albicans were grown in the presence of PH and PPFGT. Biofilm formation was tested spectrophotometrically. Exopolysaccharides (EPS) secretion was quantified using confocal scanning laser microscopy. Biofilm development was also tested on orthodontic surfaces (Essix) to assess biofilm inhibition ability on such an orthodontic appliance. Results: PPFGT and PH dose-dependently inhibited biofilm formation without affecting the planktonic growth. We found a significant reduction in biofilm total biomass using 0.625 mg/mL PPFGT and 0.16 mg/mL PH. A concentration of 0.31 mg/mL PPFGT and 0.16 mg/mL PH inhibited the total cell growth by 54% and EPS secretion by 81%. A reduction in biofilm formation and EPS secretion was also observed on orthodontic PVC surfaces. Conclusions: The polyphenolic extractions PPFGT and PH have an inhibitory effect on S. mutans and C. albicans biofilm formation and EPS secretion.


2012 ◽  
Vol 11 (8) ◽  
pp. 1012-1020 ◽  
Author(s):  
Alessandro Fiori ◽  
Soňa Kucharíková ◽  
Gilmer Govaert ◽  
Bruno P. A. Cammue ◽  
Karin Thevissen ◽  
...  

ABSTRACT The consequences of deprivation of the molecular chaperone Hsp104 in the fungal pathogen Candida albicans were investigated. Mutants lacking HSP104 became hypersusceptible to lethally high temperatures, similarly to the corresponding mutants of Saccharomyces cerevisiae , whereas normal susceptibility was restored upon reintroduction of the gene. By use of a strain whose only copy of HSP104 is an ectopic gene under the control of a tetracycline-regulated promoter, expression of Hsp104 prior to the administration of heat shock could be demonstrated to be sufficient to confer protection from the subsequent temperature increase. This result points to a key role for Hsp104 in orchestrating the cell response to elevated temperatures. Despite their not showing evident growth or morphological defects, biofilm formation by cells lacking HSP104 proved to be defective in two established in vitro models that use polystyrene and polyurethane as the substrates. Biofilms formed by the wild-type and HSP104 -reconstituted strains showed patterns of intertwined hyphae in the extracellular matrix. In contrast, biofilm formed by the hsp104 Δ/ hsp104 Δ mutant showed structural defects and appeared patchy and loose. Decreased virulence of the hsp104 Δ/ hsp104 Δ mutant was observed in the Caenorhabditis elegans infection model, in which high in vivo temperature does not play a role. In agreement with the view that stress responses in fungal pathogens may have evolved to provide niche-specific adaptation to environmental conditions, these results provide an indication of a temperature-independent role for Hsp104 in support of Candida albicans virulence, in addition to its key role in governing thermotolerance.


2006 ◽  
Vol 5 (10) ◽  
pp. 1604-1610 ◽  
Author(s):  
Clarissa J. Nobile ◽  
Jeniel E. Nett ◽  
David R. Andes ◽  
Aaron P. Mitchell

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.


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