Faculty Opinions recommendation of Sexual biofilm formation in Candida tropicalis opaque cells.

ABSTRACT Systemic infections of Candida species pose a significant threat to public health. Toxicity associated with current therapies and emergence of resistant strains present major therapeutic challenges. Here, we report exploitation of the probiotic properties of two novel, food-derived yeasts, Saccharomyces cerevisiae (strain KTP) and Issatchenkia occidentalis (strain ApC), as an alternative approach to combat widespread opportunistic fungal infections. Both yeasts inhibit virulence traits such as adhesion, filamentation, and biofilm formation of several non-albicans Candida species, including Candida tropicalis, Candida krusei, Candida glabrata, and Candida parapsilosis as well as the recently identified multidrug-resistant species Candida auris. They inhibit adhesion to abiotic surfaces as well as cultured colon epithelial cells. Furthermore, probiotic treatment blocks the formation of biofilms of individual non-albicans Candida strains as well as mixed-culture biofilms of each non-albicans Candida strain in combination with Candida albicans. The probiotic yeasts attenuated non-albicans Candida infections in a live animal. In vivo studies using Caenorhabditis elegans suggest that exposure to probiotic yeasts protects nematodes from infection with non-albicans Candida strains compared to worms that were not exposed to the probiotic yeasts. Furthermore, application of probiotic yeasts postinfection with non-albicans Candida alleviated pathogenic colonization of the nematode gut. The probiotic properties of these novel yeasts are better than or comparable to those of the commercially available probiotic yeast Saccharomyces boulardii, which was used as a reference strain throughout this study. These results indicate that yeasts derived from food sources could serve as an effective alternative to antifungal therapy against emerging pathogenic Candida species. IMPORTANCE Non-albicans Candida-associated infections have emerged as a major risk factor in the hospitalized and immunecompromised patients. Besides, antifungal-associated complications occur more frequently with these non-albicans Candida species than with C. albicans. Therefore, as an alternative approach to combat these widespread non-albicans Candida-associated infections, here we showed the probiotic effect of two yeasts, Saccharomyces cerevisiae (strain KTP) and Issatchenkia occidentalis (ApC), in preventing adhesion and biofilm formation of five non-albicans Candida strains, Candida tropicalis, Candida krusei, Candida glabrata, Candida parapsilosis, and Candida auris. The result would influence the current trend of the conversion of conventional antimicrobial therapy into beneficial probiotic microbe-associated antimicrobial treatment.

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Ultrastructural architecture of colonies of different morphologies produced by phenotypic switching of a clinical strain of Candida tropicalis and biofilm formation by variant phenotypes

Micron ◽

10.1016/j.micron.2011.03.008 ◽

2011 ◽

Vol 42 (7) ◽

pp. 726-732 ◽

Cited By ~ 11

Author(s):

Emanuele J.G. França ◽

Célia G.T.J. Andrade ◽

Luciana Furlaneto-Maia ◽

Rosana Serpa ◽

Marcelo T. Oliveira ◽

...

Keyword(s):

Candida Tropicalis ◽

Biofilm Formation ◽

Phenotypic Switching ◽

Clinical Strain

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Virulence Factors and Azole-Resistant Mechanism of Candida Tropicalis Isolated From Candidemia

10.21203/rs.3.rs-377398/v1 ◽

2021 ◽

Author(s):

Elahe Sasani ◽

Sadegh Khodavaisy ◽

Sassan Rezaie ◽

Mohammadreza Salehi ◽

Muhammad Getso ◽

...

Keyword(s):

Virulence Factors ◽

Candida Tropicalis ◽

Biofilm Formation ◽

Molecular Mechanisms ◽

Antifungal Susceptibility ◽

Cell Surface Hydrophobicity ◽

Surface Hydrophobicity ◽

Azole Resistance ◽

Virulence Determinants ◽

Fluconazole Resistant

Abstract Background Virulence factors intensify the pathogenicity of Candida species in candidemia. Limited knowledge exists regarding the azole-resistant mechanism and virulence factors of Candida tropicalis. Consequently, we aimed to evaluate the virulence factors and the molecular mechanisms of azole resistance among C. tropicalis isolated from bloodstream infection. Materials and methods Forty-five C. tropicalis isolates recovered from candidemia patients were evaluated for virulence factors, including extracellular enzymatic activities, cell surface hydrophobicity (CHS), and biofilm formation. Antifungal susceptibility pattern and expression level of ERG11, UPC2, MDR1, and CDR1 genes of eight azole resistance C. tropicalis isolates were assessed. Results The isolates expressed different frequencies of virulence determinants as follows: coagulase 4 (8.9%), phospholipase 4 (8.9 %), proteinase 31 (68.9 %), CSH 43 (95.6 %), esterase 43 (95.6 %), hemolysin 44 (97.8%), and biofilm formation 45 (100%). All the isolates were susceptible to amphotericin B and showed the highest resistance to voriconazole. The high expression of ERG11 and UPC2 genes in fluconazole-resistant C. tropicalis isolates were observed. Conclusion C. tropicalis isolated from candidemia patients extensively displayed capacities for biofilm formation, hemolysis, esterase activity, and hydrophobicity. In addition, the overexpression of ERG11 and UPC2 genes can be considered as one of the possible mechanisms of azole resistance.

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Indole-3-acetic acid synthesized through the indole-3-pyruvate pathway promotes Candida tropicalis biofilm formation

PLoS ONE ◽

10.1371/journal.pone.0244246 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0244246

Author(s):

Masaru Miyagi ◽

Rachel Wilson ◽

Daisuke Saigusa ◽

Keiko Umeda ◽

Reina Saijo ◽

...

Keyword(s):

Escherichia Coli ◽

Acetic Acid ◽

Candida Tropicalis ◽

Biofilm Formation ◽

Single Species ◽

Signaling Molecules ◽

Biosynthesis Pathway ◽

Metabolomic Analysis ◽

Mixed Species ◽

Indole 3 Acetic Acid

We previously found that the elevated abundance of the fungus Candida tropicalis is positively correlated with the bacteria Escherichia coli and Serratia marcescens in Crohn’s disease patients and the three pathogens, when co-cultured, form a robust mixed-species biofilm. The finding suggests that these three pathogens communicate and promote biofilm formation, possibly through secretion of small signaling molecules. To identify candidate signaling molecules, we carried out a metabolomic analysis of the single-species and triple-species cultures of the three pathogens. This analysis identified 15 metabolites that were highly increased in the triple-species culture. One highly induced metabolite was indole-3-acetic acid (IAA), which has been shown to induce filamentation of certain fungi. We thus tested the effect of IAA on biofilm formation of C. tropicalis and demonstrated that IAA promotes biofilm formation of C. tropicalis. Then, we carried out isotope tracing experiments using 13C-labeled-tryptophan as a precursor to uncover the biosynthesis pathway of IAA in C. tropicalis. The results indicated that C. tropicalis synthesizes IAA through the indole-3-pyruvate pathway. Further studies using inhibitors of the indole-3-pyruvate pathway are warranted to decipher the mechanisms by which IAA influences biofilm formation.

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Candida tropicalis RON1 is required for hyphal formation, biofilm development, and virulence but is dispensable for N-acetylglucosamine catabolism

Medical Mycology ◽

10.1093/mmy/myaa063 ◽

2020 ◽

Cited By ~ 1

Author(s):

Yu-De Song ◽

Chih-Chieh Hsu ◽

Shi Qian Lew ◽

Ching-Hsuan Lin

Keyword(s):

Candida Albicans ◽

Candida Tropicalis ◽

Biofilm Formation ◽

Carbon Sources ◽

Protein Alignment ◽

Gene Expressions ◽

Glucose Content ◽

Catabolic Genes ◽

Hyphal Formation ◽

Biofilm Development

Abstract NDT80-like family genes are highly conserved across a large group of fungi, but the functions of each Ndt80 protein are diverse and have evolved differently among yeasts and pathogens. The unique NDT80 gene in budding yeast is required for sexual reproduction, whereas three NDT80-like genes, namely, NDT80, REP1, and RON1, found in Candida albicans exhibit distinct functions. Notably, it was suggested that REP1, rather than RON1, is required for N-acetylglucosamine (GlcNAc) catabolism. Although Candida tropicalis, a widely dispersed fungal pathogen in tropical and subtropical areas, is closely related to Candida albicans, its phenotypic, pathogenic and environmental adaptation characteristics are remarkably divergent. In this study, we focused on the Ron1 transcription factor in C. tropicalis. Protein alignment showed that C. tropicalis Ron1 (CtRon1) shares 39.7% identity with C. albicans Ron1 (CaRon1). Compared to the wild-type strain, the C. tropicalis ron1Δ strains exhibited normal growth in different carbon sources and had similar expression levels of several GlcNAc catabolic genes during GlcNAc treatment. In contrast, C. tropicalis REP1 is responsible for GlcNAc catabolism and is involved in GlcNAc catabolic gene expressions, similar to C. albicans Rep1. However, REP1 deletion strains in C. tropicalis promote hyphal development in GlcNAc with low glucose content. Interestingly, CtRON1, but not CaRON1, deletion mutants exhibited significantly impaired hyphal growth and biofilm formation. As expected, CtRON1 was required for full virulence. Together, the results of this study showed divergent functions of CtRon1 compared to CaRon1; CtRon1 plays a key role in yeast-hyphal dimorphism, biofilm formation and virulence. Lay Abstract In this study, we identified the role of RON1, an NDT80-like gene, in Candida tropicalis. Unlike the gene in Candida albicans, our studies showed that RON1 is a key regulator of hyphal formation, biofilm development and virulence but is dispensable for N-acetylglucosamine catabolism in C. tropicalis.

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