scholarly journals The Heat-Induced Molecular Disaggregase Hsp104 of Candida albicans Plays a Role in Biofilm Formation and Pathogenicity in a Worm Infection Model

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.

2015 ◽  
Vol 14 (8) ◽  
pp. 834-844 ◽  
Author(s):  
Ranjith Rajendran ◽  
Elisa Borghi ◽  
Monica Falleni ◽  
Federica Perdoni ◽  
Delfina Tosi ◽  
...  

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.


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.


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.


2015 ◽  
Vol 83 (10) ◽  
pp. 3857-3864 ◽  
Author(s):  
Jessica C. Hargarten ◽  
Tyler C. Moore ◽  
Thomas M. Petro ◽  
Kenneth W. Nickerson ◽  
Audrey L. Atkin

The polymorphic commensal fungusCandida albicanscauses life-threatening disease via bloodstream and intra-abdominal infections in immunocompromised and transplant patients. Although host immune evasion is a common strategy used by successful human fungal pathogens,C. albicansprovokes recognition by host immune cells less capable of destroying it. To accomplish this,C. albicanswhite cells secrete a low-molecular-weight chemoattractive stimulant(s) of macrophages, a phagocyte that they are able to survive within and eventually escape from.C. albicansopaque cells do not secrete this chemoattractive stimulant(s). We report here a physiological mechanism that contributes to the differences in the interaction ofC. albicanswhite and opaque cells with macrophages.E,E-Farnesol, which is secreted by white cells only, is a potent stimulator of macrophage chemokinesis, whose activity is enhanced by yeast cell wall components and aromatic alcohols.E,E-farnesol results in up to an 8.5-fold increase in macrophage migrationin vitroand promotes a 3-fold increase in the peritoneal infiltration of macrophagesin vivo. Therefore, modulation of farnesol secretion to stimulate host immune recognition by macrophages may help explain why this commensal is such a successful pathogen.


Author(s):  
Gabriela Fernanda Bombarda ◽  
Janaina de Cássia Orlandi Sardi ◽  
Pedro L. Rosalen ◽  
Josy G. Lazarini ◽  
Eder R. Paganini ◽  
...  

Biofilms are organized microbial communities formed from an ecological succession. Biofilm formation functions as a mechanism of virulence and favors the development of diseases, including oral diseases such as dental caries and periodontal disease, in which the microorganisms Streptococcus mutans and Candida albicans are closely related. Previous studies have shown that interactions between S. mutans and C. albicans are associated with the pathogenesis of early childhood caries (ECC). Therefore, there is a great interest in finding new prototypes for antimicrobial drugs, mainly for the development of structural analogues of chalcones, which constitute one of the largest classes of natural products belonging to the flavonoid family and are considered strategic molecules for this purpose.


2009 ◽  
Vol 9 (2) ◽  
pp. 266-277 ◽  
Author(s):  
Suresh K. A. Palanisamy ◽  
Melissa A. Ramirez ◽  
Michael Lorenz ◽  
Samuel A. Lee

ABSTRACT To investigate the role of the prevacuolar secretion pathway in biofilm formation and virulence in Candida albicans, we cloned and analyzed the C. albicans homolog of the Saccharomyces cerevisiae prevacuolar trafficking gene PEP12. C. albicans PEP12 encodes a deduced t-SNARE that is 28% identical to S. cerevisiae Pep12p, and plasmids bearing C. albicans PEP12 complemented the abnormal vacuolar morphology and temperature-sensitive growth of an S. cerevisiae pep12 null mutant. The C. albicans pep12 Δ null mutant was defective in endocytosis and vacuolar acidification and accumulated 40- to 60-nm cytoplasmic vesicles near the plasma membrane. Secretory defects included increased extracellular proteolytic activity and absent lipolytic activity. The pep12Δ null mutant was more sensitive to cell wall stresses and antifungal agents than the isogenic complemented strain or the control strain DAY185. Notably, the biofilm formed by the pep12Δ mutant was reduced in overall mass and fragmented completely upon the slightest disturbance. The pep12Δ mutant was markedly reduced in virulence in an in vitro macrophage infection model and an in vivo mouse model of disseminated candidiasis. These results suggest that C. albicans PEP12 plays a key role in biofilm integrity and in vivo virulence.


2014 ◽  
Vol 58 (4) ◽  
pp. 2344-2355 ◽  
Author(s):  
De-Dong Li ◽  
Lan-Xue Zhao ◽  
Eleftherios Mylonakis ◽  
Gan-Hai Hu ◽  
Yong Zou ◽  
...  

ABSTRACTPterostilbene (PTE) is a stilbene-derived phytoalexin that originates from several natural plant sources. In this study, we evaluated the activity of PTE againstCandida albicansbiofilms and explored the underlying mechanisms. In 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assays, biofilm biomass measurement, confocal laser scanning microscopy, and scanning electron microscopy, we found that ≤16 μg/ml PTE had a significant effect againstC. albicansbiofilmsin vitro, while it had no fungicidal effect on planktonicC. albicanscells, which suggested a unique antibiofilm effect of PTE. Then we found that PTE could inhibit biofilm formation and destroy the maintenance of mature biofilms. At 4 μg/ml, PTE decreased cellular surface hydrophobicity (CSH) and suppressed hyphal formation. Gene expression microarrays and real-time reverse transcription-PCR showed that exposure ofC. albicansto 16 μg/ml PTE altered the expression of genes that function in morphological transition, ergosterol biosynthesis, oxidoreductase activity, and cell surface and protein unfolding processes (heat shock proteins). Filamentation-related genes, especially those regulated by the Ras/cyclic AMP (cAMP) pathway, includingECE1,ALS3,HWP1,HGC1, andRAS1itself, were downregulated upon PTE treatment, indicating that the antibiofilm effect of PTE was related to the Ras/cAMP pathway. Then, we found that the addition of exogenous cAMP reverted the PTE-induced filamentous growth defect. Finally, with a rat central venous catheter infection model, we confirmed thein vivoactivity of PTE againstC. albicansbiofilms. Collectively, PTE had strong activities againstC. albicansbiofilms bothin vitroandin vivo, and these activities were associated with the Ras/cAMP pathway.


2017 ◽  
Vol 85 (11) ◽  
Author(s):  
Audrey C. Bergeron ◽  
Brittany G. Seman ◽  
John H. Hammond ◽  
Linda S. Archambault ◽  
Deborah A. Hogan ◽  
...  

ABSTRACT Polymicrobial infections often include both fungi and bacteria and can complicate patient treatment and resolution of infection. Cross-kingdom interactions among bacteria, fungi, and/or the immune system during infection can enhance or block virulence mechanisms and influence disease progression. The fungus Candida albicans and the bacterium Pseudomonas aeruginosa are coisolated in the context of polymicrobial infection at a variety of sites throughout the body, including mucosal tissues such as the lung. In vitro, C. albicans and P. aeruginosa have a bidirectional and largely antagonistic relationship. Their interactions in vivo remain poorly understood, specifically regarding host responses in mediating infection. In this study, we examine trikingdom interactions using a transparent juvenile zebrafish to model mucosal lung infection and show that C. albicans and P. aeruginosa are synergistically virulent. We find that high C. albicans burden, fungal epithelial invasion, swimbladder edema, and epithelial extrusion events serve as predictive factors for mortality in our infection model. Longitudinal analyses of fungal, bacterial, and immune dynamics during coinfection suggest that enhanced morbidity is associated with exacerbated C. albicans pathogenesis and elevated inflammation. The P. aeruginosa quorum-sensing-deficient ΔlasR mutant also enhances C. albicans pathogenicity in coinfection and induces extrusion of the swimbladder. Together, these observations suggest that C. albicans-P. aeruginosa cross talk in vivo can benefit both organisms to the detriment of the host.


Author(s):  
Ruan Fourie ◽  
Jacobus Albertyn ◽  
Olihile Sebolai ◽  
Onele Gcilitshana ◽  
Carolina H. Pohl

The yeast Candida albicans exhibits multiple morphologies dependent on environmental cues. Candida albicans biofilms are frequently polymicrobial, enabling interspecies interaction through proximity and contact. The interaction between C. albicans and the bacterium, Pseudomonas aeruginosa, is antagonistic in vitro, with P. aeruginosa repressing the yeast-to-hyphal switch in C. albicans. Previous transcriptional analysis of C. albicans in polymicrobial biofilms with P. aeruginosa revealed upregulation of genes involved in regulation of morphology and biofilm formation, including SET3, a component of the Set3/Hos2 histone deacetylase complex (Set3C). This prompted the question regarding the involvement of SET3 in the interaction between C. albicans and P. aeruginosa, both in vitro and in vivo. We found that SET3 may influence early biofilm formation by C. albicans and the interaction between C. albicans and P. aeruginosa. In addition, although deletion of SET3 did not alter the morphology of C. albicans in the presence of P. aeruginosa, it did cause a reduction in virulence in a Caenorhabditis elegans infection model, even in the presence of P. aeruginosa.


2012 ◽  
Vol 80 (10) ◽  
pp. 3660-3668 ◽  
Author(s):  
Mohammad Shahrooei ◽  
Vishal Hira ◽  
Laleh Khodaparast ◽  
Ladan Khodaparast ◽  
Benoit Stijlemans ◽  
...  

ABSTRACTThe increased use of medical implants has resulted in a concomitant rise in device-related infections. The majority of these infections are caused byStaphylococcus epidermidisbiofilms. Immunoprophylaxis and immunotherapy targetingin vivo-expressed, biofilm-associated, bacterial cell surface-exposed proteins are promising new approaches to prevent and treat biofilm-related infections, respectively. Using anin silicoprocedure, we identified 64 proteins that are predicted to beS.epidermidissurface exposed (Ses), of which 36 were annotated as (conserved) hypothetical. Of these 36 proteins, 5 proteins—3 LPXTG motif-containing proteins (SesL, SesB, and SesC) and 2 of the largest ABC transporters (SesK and SesM)—were selected for evaluation as vaccine candidates. This choice was based on protein size, number of antigenic determinants, or the established role inS. epidermidisbiofilm formation of the protein family to which the candidate protein belongs. Anti-SesC antibodies exhibited the greatest inhibitory effect onS. epidermidisbiofilm formationin vitroand on colonization and infection in a mouse jugular vein catheter infection model that includes biofilms and organ infections. Active vaccination with a recombinant truncated SesC inhibitedS. epidermidisbiofilm formation in a rat model of subcutaneous foreign body infection. Antibodies to SesC were shown to be opsonic by anin vitroopsonophagocytosis assay. We conclude that SesC is a promising target for antibody mediated strategies againstS. epidermidisbiofilm formation.


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