scholarly journals A Re-Evaluation of the Relationship between Morphology and Pathogenicity in Candida Species

2020 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
David Kadosh ◽  
Vasanthakrishna Mundodi
Keyword(s):  
Candida Albicans ◽  
Candida Species ◽  
Fungal Pathogen ◽  
Future Research ◽  
Morphological Transition ◽  
Definitive Evidence ◽  
Human Fungal Pathogen ◽  
The Relationship ◽  
Lines Of Evidence

Many pathogenic Candida species possess the ability to undergo a reversible morphological transition from yeast to filamentous cells. In Candida albicans, the most frequently isolated human fungal pathogen, multiple lines of evidence strongly suggest that this transition is associated with virulence and pathogenicity. While it has generally been assumed that non-albicans Candida species (NACS) are less pathogenic than C. albicans, in part, because they do not filament as well, definitive evidence is lacking. Interestingly, however, a recent study suggests that filamentation of NACS is associated with reduced, rather than increased, pathogenicity. These findings, in turn, challenge conventional views and suggest that there are fundamental evolutionary differences in the morphology–pathogenicity relationship in C. albicans vs. NACS. The findings also raise many new and intriguing questions and open new avenues for future research, which are discussed.

scholarly journals Simple Carbohydrate Derivatives Diminish the Formation of Biofilm of the Pathogenic Yeast Candida albicans

Antibiotics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 10 ◽  
Author(s):  
Olena P. Ishchuk ◽  
Olov Sterner ◽  
Ulf Ellervik ◽  
Sophie Manner
Keyword(s):  
Candida Albicans ◽  
Fungal Pathogen ◽  
Biofilm Formation ◽  
Untreated Control ◽  
Morphological Transition ◽  
Pathogenic Yeast ◽  
Yeast Form ◽  
Human Fungal Pathogen ◽  
Morphological Transitions ◽  
Simple Carbohydrate

The opportunistic human fungal pathogen Candida albicans relies on cell morphological transitions to develop biofilm and invade the host. In the current study, we developed new regulatory molecules, which inhibit the morphological transition of C. albicans from yeast-form cells to cells forming hyphae. These compounds, benzyl α-l-fucopyranoside and benzyl β-d-xylopyranoside, inhibit the hyphae formation and adhesion of C. albicans to a polystyrene surface, resulting in a reduced biofilm formation. The addition of cAMP to cells treated with α-l-fucopyranoside restored the yeast-hyphae switch and the biofilm level to that of the untreated control. In the β-d-xylopyranoside treated cells, the biofilm level was only partially restored by the addition of cAMP, and these cells remained mainly as yeast-form cells.

scholarly journals Induction of theCandida albicansFilamentous Growth Program by Relief of Transcriptional Repression: A Genome-wide Analysis

2005 ◽  
Vol 16 (6) ◽  
pp. 2903-2912 ◽  
Author(s):  
David Kadosh ◽  
Alexander D. Johnson
Keyword(s):  
Candida Albicans ◽  
Transcriptional Repression ◽  
Fungal Pathogen ◽  
Morphological Transition ◽  
Whole Genome ◽  
Transcriptional Repressors ◽  
Genome Wide Analysis ◽  
Human Fungal Pathogen ◽  
Genome Wide ◽  
A Genome

Candida albicans, the major human fungal pathogen, undergoes a reversible morphological transition from blastospores (round budding cells) to filaments (elongated cells attached end-to-end). This transition, which is induced upon exposure of C. albicans cells to a number of host conditions, including serum and body temperature (37°C), is required for virulence. Using whole-genome DNA microarray analysis, we describe 61 genes that are significantly induced (≥2-fold) during the blastospore to filament transition that takes place in response to exposure to serum and 37°C. We next show that approximately half of these genes are transcriptionally repressed in the blastospore state by three transcriptional repressors, Rfg1, Nrg1, and Tup1. We conclude that the relief of this transcriptional repression plays a key role in bringing the C. albicans filamentous growth program into play, and we describe the framework of this transcriptional circuit.

scholarly journals Simple Carbohydrate Derivatives Diminish the Formation of Biofilm of Candida albicans

2019 ◽  
Author(s):  
Olena P. Ishchuk ◽  
Olov Sterner ◽  
Ulf Ellervik ◽  
Sophie Manner
Keyword(s):  
Candida Albicans ◽  
Fungal Pathogen ◽  
Biofilm Formation ◽  
Untreated Control ◽  
Morphological Transition ◽  
Yeast Form ◽  
Polystyrene Surface ◽  
Human Fungal Pathogen ◽  
Morphological Transitions ◽  
Simple Carbohydrate

Abstract The opportunistic human fungal pathogen Candida albicans rely on cell morphological transitions to develop biofilm and invade the host. In the current study, we developed new regulatory molecules, which inhibit the morphological transition of C. albicans from yeast-form cells to cells forming hyphae. These compounds, benzyl α-L-fucopyranoside and benzyl β-D-xylopyranoside, inhibit the morphological switching and adhesion of C. albicans to a polystyrene surface, resulting in a reduced biofilm formation. The addition of cAMP to cells treated with α-L-fucopyranoside restored the yeast-hyphae switch and the biofilm level to that of the untreated control. In the β-D-xylopyranoside treated cells, the biofilm level was only partially restored by the addition of cAMP, and these cells remained mainly as yeast-form cells.

scholarly journals Simple Carbohydrate Derivatives Diminish the Formation of Biofilm of Candida albicans

2019 ◽  
Author(s):  
Olena P. Ishchuk ◽  
Olov Sterner ◽  
Ulf Ellervik ◽  
Sophie Manner
Keyword(s):  
Candida Albicans ◽  
Fungal Pathogen ◽  
Biofilm Formation ◽  
Untreated Control ◽  
Morphological Transition ◽  
Yeast Form ◽  
Polystyrene Surface ◽  
Human Fungal Pathogen ◽  
Morphological Transitions ◽  
Simple Carbohydrate

Abstract The opportunistic human fungal pathogen Candida albicans rely on cell morphological transitions to develop biofilm and invade the host. In the current study, we developed new regulatory molecules, which inhibit the morphological transition of C. albicans from yeast-form cells to cells forming hyphae. These compounds, benzyl α-L-fucopyranoside and benzyl β-D-xylopyranoside, inhibit the morphological switching and adhesion of C. albicans to a polystyrene surface, resulting in a reduced biofilm formation. The addition of cAMP to cells treated with α-L-fucopyranoside restored the yeast-hyphae switch and the biofilm level to that of the untreated control. In the β-D-xylopyranoside treated cells, the biofilm level was only partially restored by the addition of cAMP, and these cells remained mainly as yeast-form cells.

scholarly journals pH-Dependant Antifungal Activity of Valproic Acid against the Human Fungal Pathogen Candida albicans

2017 ◽  
Vol 8 ◽  
Author(s):  
Julien Chaillot ◽  
Faiza Tebbji ◽  
Carlos García ◽  
Hugo Wurtele ◽  
René Pelletier ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Fungal Pathogen ◽  
Human Fungal Pathogen

scholarly journals Pmt-Mediated O Mannosylation Stabilizes an Essential Component of the Secretory Apparatus, Sec20p, in Candida albicans

2004 ◽  
Vol 3 (5) ◽  
pp. 1164-1168 ◽  
Author(s):  
Yvonne Weber ◽  
Stephan K.-H. Prill ◽  
Joachim F. Ernst
Keyword(s):  
Endoplasmic Reticulum ◽  
Candida Albicans ◽  
Fungal Pathogen ◽  
Wild Type ◽  
Rapid Degradation ◽  
Vesicle Traffic ◽  
Human Fungal Pathogen ◽  
Low Levels ◽  
Lumenal Domain ◽  
Secretory Apparatus

ABSTRACT Sec20p is an essential endoplasmic reticulum (ER) membrane protein in yeasts, functioning as a tSNARE component in retrograde vesicle traffic. We show that Sec20p in the human fungal pathogen Candida albicans is extensively O mannosylated by protein mannosyltransferases (Pmt proteins). Surprisingly, Sec20p occurs at wild-type levels in a pmt6 mutant but at very low levels in pmt1 and pmt4 mutants and also after replacement of specific Ser/Thr residues in the lumenal domain of Sec20p. Pulse-chase experiments revealed rapid degradation of unmodified Sec20p (38.6 kDa) following its biosynthesis, while the stable O-glycosylated form (50 kDa) was not formed in a pmt1 mutant. These results suggest a novel function of O mannosylation in eukaryotes, in that modification by specific Pmt proteins will prevent degradation of ER-resident membrane proteins via ER-associated degradation or a proteasome-independent pathway.

scholarly journals In Fungal Intracellular Pathogenesis, Form Determines Fate

mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Robin C. May ◽  
Arturo Casadevall
Keyword(s):  
Candida Albicans ◽  
Fungal Pathogen ◽  
Membrane Integrity ◽  
Pathogenic Fungi ◽  
Morphological Transition ◽  
Physical Damage ◽  
Fungal Cell ◽  
Morphological Transitions ◽  
Pathogenic Microbes ◽  
Phagosomal Membrane

ABSTRACT For pathogenic microbes to survive ingestion by macrophages, they must subvert powerful microbicidal mechanisms within the phagolysosome. After ingestion, Candida albicans undergoes a morphological transition producing hyphae, while the surrounding phagosome exhibits a loss of phagosomal acidity. However, how these two events are related has remained enigmatic. Now Westman et al. (mBio 9:e01226-18, 2018, https://doi.org/10.1128/mBio.01226-18) report that phagosomal neutralization results from disruption of phagosomal membrane integrity by the enlarging hyphae, directly implicating the morphological transition in physical damage that promotes intracellular survival. The C. albicans intracellular strategy shows parallels with another fungal pathogen, Cryptococcus neoformans, where a morphological changed involving capsular enlargement intracellularly is associated with loss of membrane integrity and death of the host cell. These similarities among distantly related pathogenic fungi suggest that morphological transitions that are common in fungi directly affect the outcome of the fungal cell-macrophage interaction. For this class of organisms, form determines fate in the intracellular environment.

scholarly journals The 5’ untranslated region of theEFG1transcript promotes its translation to regulate hyphal morphogenesis inCandida albicans

2018 ◽  
Author(s):  
Prashant R. Desai ◽  
Klaus Lengeler ◽  
Mario Kapitan ◽  
Silas Matthias Janßen ◽  
Paula Alepuz ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Fungal Pathogen ◽  
Regulatory Mechanisms ◽  
Untranslated Regions ◽  
Regulatory Sequence ◽  
Transcriptional Level ◽  
Human Fungal Pathogen ◽  
Hyphal Morphogenesis ◽  
Cellular Morphogenesis ◽  
Incandida Albicans

ABSTRACTExtensive 5’ untranslated regions (UTR) are a hallmark of transcripts determining hyphal morphogenesis inCandida albicans.The major transcripts of theEFG1gene, which are responsible for cellular morphogenesis and metabolism, contain a 5’ UTR of up to 1170 nt. Deletion analyses of the 5’ UTR revealed a 218 nt sequence that is required for production of the Efg1 protein and its functions in filamentation, without lowering the level and integrity of theEFG1transcript. Polysomal analyses revealed that the 218 nt 5’ UTR sequence is required for efficient translation of the Efg1 protein. Replacement of theEFG1ORF by the heterologous reporter geneCaCBGlucconfirmed the positive regulatory importance of the identified 5’ UTR sequence. In contrast to other reported transcripts containing extensive 5’ UTR sequences, these results indicate the positive translational function of the 5’ UTR sequence in theEFG1transcript, which is observed in context of the nativeEFG1promoter. The results suggest that the 5’ UTR recruits regulatory factors, possibly during emergence of the native transcript, which aid in translation of theEFG1transcript.IMPORTANCEMany of the virulence traits that makeCandida albicansan important human fungal pathogen are regulated on a transcriptional level. Here we report an important regulatory contribution of translation, which is exerted by the extensive 5’ untranslated regulatory sequence (5’ UTR) of the transcript for the protein Efg1, which determines growth, metabolism and filamentation in the fungus. Presence of the 5’ UTR is required for efficient translation of Efg1, to promote filamentation. Because transcripts for many relevant regulators contain extensive 5’ UTR sequences, it appears that virulence ofC. albicansdepends on the combination of transcriptional and translation regulatory mechanisms.

scholarly journals Sub-MIC levels of purpurin inhibit membrane ATPase-mediated proton efflux activity in the human fungal pathogen Candida albicans

2014 ◽  
Vol 67 (4) ◽  
pp. 349-350 ◽  
Author(s):  
Paul Wai-Kei Tsang ◽  
Alan Pak-Kin Wong ◽  
Han-Sung Jung ◽  
Wing-Ping Fong
Keyword(s):  
Candida Albicans ◽  
Fungal Pathogen ◽  
Proton Efflux ◽  
Human Fungal Pathogen ◽  
Membrane Atpase
Sign in / Sign up

Export Citation Format

Share Document