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: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:The ability of the fungus Candida albicans to filament and form biofilms contributes to its burden as a leading cause of hospital-acquired infections. Biofilm development involves an interconnected transcriptional regulatory network (TRN) consisting of nine transcription factors (TFs) that bind both to their own regulatory regions and to those of the other network TFs. Here, we show that seven of the nine TFs in the C. albicans biofilm network contain prion-like domains (PrLDs) that have been linked to the ability to form phase-separated condensates. Construction of PrLD mutants in four biofilm TFs reveals that these domains are essential for filamentation and biofilm formation in C. albicans. Moreover, biofilm PrLDs promote the formation of phase-separated condensates in the nuclei of live cells, and PrLD mutations that abolish phase separation (such as the removal of aromatic residues) also prevent biofilm formation. Biofilm TF condensates can selectively recruit other TFs through PrLD-PrLD interactions and can co-recruit RNA polymerase II, implicating condensate formation in the assembly of active transcriptional complexes. Finally, we show that PrLD mutations that block the phase separation of biofilm TFs also prevent filamentation in an in vivo model of gastrointestinal colonization. Together, these studies associate transcriptional condensates with the regulation of filamentation and biofilm formation in C. albicans, and highlight how targeting of PrLD-PrLD interactions could prevent pathogenesis by this species.
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:Identification of proteins in Candida albicans biofilm-derived extracellular vesicles. Raw data underlying data published in https://doi.org/10.3390/jof9111078.
Project description:Natural product cinnamaldehyde has significant antifungal activities, and its inhibitory activity against Candida albicans has been reported. Up to now, there are few reports on the changes in the transcriptome of Candida albicans after cinnamaldehyde treatment. Here, RNA sequencing analysis of samples obtained from Candida albicans cells grown in the presence or absence of cinnamaldehyde was performed. A total of 123 differentially expressed genes were identified, of which 15 genes were up-regulated and 108 genes were down-regulated.