Project description:Candida spp. are commensal opportunistic fungal pathogens that often colonize and infect mucosal surfaces of the human body. Candida, along with other microbes in the microbiota, generally grow as biofilms in a polymicrobial environment. Due to the nature of cellular growth in a biofilm (such as production of a protective extracellular matrix) and the recalcitrance of biofilms, infections involving biofilms are very difficult to treat with antibiotics and perpetuate the cycle of infection. The two most commonly isolated Candida spp. from Candida infections are Candida albicans and Candida glabrata, and the presence of both of these species results in increased patient inflammation and overall biofilm formation. This work aims to investigate the interspecies interactions between C. albicans (Ca) and C. glabrata (Cg) in co-culture through transcriptome analysis over the course of biofilm growth. We report that during co-culture, lipid biosynthesis and transporter genes were significantly modulated in both Ca and Cg. Differentially expressed genes in Ca during co-culture growth included putative transporter genes (C2_02180W_A and C1_09210C_B; up-regulated), amino acid biosynthesis (ARO7; up-regulated most in Ca:Cg 1:3), and lipid-related genes (LIP3 and IPT1; down-regulated). Differentially expressed genes in Cg in co-culture included putative transmembrane transporters (CAGL0H03399g and CAGL0K04609g; up-regulated), an oxidative stress response gene (CAGL0E04114g; down-regulated most in Ca:Cg 1:3), genes involved in the TCA cycle (LYS12 and CAGL0J06402g; down-regulated), and several genes involved in cell wall/membrane biosynthesis (SEC53, GAS2, VIG9; down-regulated). Additionally, confocal microscopy was utilized for membrane lipid analysis between monoculture and co-culture biofilms. Through filipin-stained lipid analysis, we found that there was a significant increase in cell membrane lipid content in Ca:Cg 1:3 biofilms compared to Ca and Ca:Cg 3:1 biofilms. These results suggest substantial modifications of both cell wall, cell membrane, and transporters in both Ca and Cg during the time course of co-culture growth, which allows for increased biofilm formation and virulence in Candida co-culture biofilms.
Project description:Transcriptional profiling of Candida albicans cells grown under planktonic and biofilm-inducing conditions, comparing SN76 and sfl1Δ/sfl1Δ strains. Goal was to study the effect of SFL1 deletion on the transcriptomic profile of C. albicans planktonic and biofilm cells under acidic conditions, in order to reveal the function of the Sfl1 transcription factor in C. albicans biofilm development.
Project description:To identify novel genes modulating Candida albicans biofilm formation, a screen of 2451 overexpression strains allowed us to identify 16 genes whose overexpression significantly reduced biofilm formation. Genome-wide expression and binding analyses were conducted upon overexpression of ZCF15 and ZCF26 and wild type planktonic and biofilm cells were performed. This study has identified new sets of biofilm regulators, including ZCF15 and ZCF26 whose specific role in metabolic remodelling during C. Albicans biofilm development. Triplicates data of RNAseq data are provided here with 6 conditions including the ZCF15 and ZCF16 cases mentioned here above
Project description:Candida albicans can form biofilm on the surface of indwelling medical devices. Biofilm formation is an importanat clinical problem because biofilm-grown cells have decreased susceptibility to antifungal agents. Microarray technology was used to identify changes in gene expression during biofilm development. Two biofilm substrates (denture and catheter) were used, with two C. albicans strains tested on each substrate. Three phases of biofilm development were studies: early (6 h), intermediate (12 h), and mature (48 h). Planktonic specimens were collected at the same time points. Comparison between biofilm and planktonic cell transcriptional profiles at each time point showed differential expression of approximately 3% of the genome in biofilm. Fewer than half of these genes were up-regulated in biofilm, compared to planktonic cells. Transcriptional profiles were also analyzed over the time course of biofilm development. Genes up-regulated during the early phase (6 h) primarily were involved in glycolytic and non-glycolytic carbohydrate assimilation, and amino acid metabolism. The largest number of differentially expressed genes were identified at the intermediate phase (12 h) of biofilm development where the largest increase in biofilm biomass occurs. Genes up-regulated at 12 h were involved in transcription, protein synthesis/translation, energy generation, cellular transport, and nucleotide metabolism. At mature phase (48 h), few genes were up-regulated compared to the 12 h time point. These data define phase-dependent changes in gene expression that occur during biofilm development and show how genes belong to different, but interconnected, functional categories regulate the morphology and phenotype of C. albicans biofilm Keywords: phase-dependent gene expression; comparative genomic hybridization; cell type comparison
Project description:Candida albicans, a major human fungal pathogen, can form biofilms on a variety of inert and biological surfaces. C. albicans biofilms allow for immune evasion, are highly resistant to antifungal therapies and represent a significant complication for a wide variety of immunocompromised patients in clinical settings. While transcriptional regulators and global transcriptional profiles of C. albicans biofilm formation have been well-characterized, very little is known about translational regulation of this important C. albicans virulence property. Here, using ribosome profiling, we define the first global translational profile of genes that is expressed during early biofilm development in a human fungal pathogen, C. albicans. We show that C. albicans biofilm formation involves altered translational regulation of gene classes associated with protein synthesis, transport, plasma membrane, cell wall, polarized growth, cell cycle, secretion, and signal transduction. Interestingly, while similar, but not identical, classes of genes showed transcriptional alterations during early C. albicans biofilm development, we observed very little overlap between specific genes that are up-regulated or down-regulated at the translational vs. transcriptional levels. Our results suggest that distinct translational mechanisms, which could potentially be targeted by novel antifungal strategies, play an important role in directing biofilm development of a major human fungal pathogen.
Project description:Biofilms are sessile microbial communities that are often resistant to conventional antimicrobial therapeutics and the host immune system. Candida albicans is an opportunistic pathogenic yeast and responsible for candidiasis. It readily colonizes host tissues and implant devices, and forms biofilms, which play an important role in pathogenesis and drug resistance. Its morphological transition from budding yeast to hyphal form and subsequent biofilm formation is regarded as the crucial factor for drug tolerance and virulence of Candida infections. In this study, nepodin (also called musizin) from Rumex japonicus root was investigated for antibiofilm, antihyphae, and antivirulence activities against fluconazole-resistant C. albicans strain. Nepodin at 2 µg/ml from Rumex plant effectively inhibited C. albicans biofilm formation by more than 90% but had no effect on planktonic cell growth. Also, Rumex root extract and nepodin inhibited hyphal growth and cell aggregation of C. albicans. Interestingly, nepodin also showed antibiofilm activity against Staphylococcus aureus or A. baumannii strains and two systems of dual biofilms of C. albicans and S. aureus or A. baumannii, respectively. Transcriptomic analysis using RNA-seq and qRT-PCR showed nepodin repressed the expressions of several hypha/biofilm related genes (ECE1, HWP1, and UME6) and overexpressed several transport genes (CDR4, CDR11, IFD6, and TPO2), which supported observed phenotypic changes.
Project description:Abstract: Candida parapsilosis and Candida albicans are human fungal pathogens that belong to the CUG clade in the Saccharomycotina. In contrast to C. albicans, relatively little is known about the virulence properties of C. parapsilosis, a pathogen particularly associated with infections of premature neonates. We describe here the construction of >200 C. parapsilosis strains carrying double allele deletions of transcription factors, protein kinases and species-specific genes. Two independent deletions were constructed for each target gene. Growth in > 40 conditions was tested, including carbon source, temperature, and the presence of antifungal drugs. The phenotypes were compared to C. albicans strains with deletions of orthologous transcription factors. We found that many phenotypes are shared between the two species, such as the role of Upc2 as a regulator of azole resistance. Others are unique. For example, Cph2 plays a role in the hypoxic response in C. parapsilosis and not in C. albicans. We found extensive divergence between the biofilm regulators of the two species. We identified 7 transcription factors and one protein kinase that are required for biofilm development in C. parapsilosis. Only three (Efg1, Bcr1, and Ace2) have similar effects on C. albicans biofilms, whereas Cph2, Czf1, Gzf3 and Ume6 have major roles in C. parapsilosis only. In addition, two transcription factors (Brg1 and Tec1) with well-characterized roles in biofilm formation in C. albicans do not have the same function in C. parapsilosis. We also compared the transcription profile of C. parapsilosis and C. albicans biofilms. Our analysis suggests the processes shared between the two species are predominantly metabolic.