Project description:Invasive fungal infections are important healthcare associated disease worldwide especially in intensive care units More recently, Candida auris a multidrug and potentially pan-resistant species has globally emerged as a new nosocomial pathogen, which has been already reported from at least 50 countries on six continents. Clinical studies showed that previously well-defined phylogenetic C. auris clades display significant differences regarding their pathogenicity, virulence, metabolism and susceptibility profile to traditional antifungal therapies. Based on epidemiological data, isolates belonging to the South Asian clade show the highest ratio of resistance to fluconazole (97%), amphotericin B (47%) and this clade involves the highest number of multidrug resistant isolates (45%), which compromise the efficacy of applied antifungal therapy. In the past decade, a new broad-spectrum antifungal drug, isavuconazole (ISA), has been introduced into clinical practice. ISA is primarily approved for the treatment of invasive aspergillosis and mucormycosis, and currently, there are no available recommendations for the therapy of invasive Candida infections. In our previous study, we reported different ISA susceptibility profiles between isolates belonging to South Asian lineage. However, the global transcriptional - even isolate specific - response remained unresolved. Therefore, our study aimed to reveal those molecular events, which are associated with ISA exposure using high throughput RNA sequencing (RNAseq).
Project description:Fungal infections are a major health concern because of limited antifungal drugs and development of drug resistance. Candida can develop azole drug resistance by overexpression of drug efflux pumps or mutating ERG11, the target of azoles. However, the role of epigenetic histone modifications in azole-induced gene expression and drug resistance is poorly understood in Candida glabrata. In this study, we show that Set1 mediates histone H3K4 methylation in C. glabrata. In addition, loss of SET1 and histone H3K4 methylation increases azole susceptibility in both C. glabrata and S. cerevisiae. This increase in azole susceptibility in S. cerevisiae and C. glabrata strains lacking SET1 is due to distinct mechanisms. For S. cerevisiae, loss of SET1 decreased the expression and function of the efflux pump Pdr5, but not ERG11 expression under azole treatment. In contrast, loss of SET1 in C. glabrata does not alter expression or function of efflux pumps. However, RNA sequencing revealed that C. glabrata Set1 is necessary for azole-induced expression of all 12 genes in the late ergosterol biosynthesis pathway, including ERG11 and ERG3. Furthermore, chromatin immunoprecipitation analysis shows histone H3K4 trimethylation increases upon azole-induced ERG gene expression. In addition, high performance liquid chromatography analysis indicated Set1 is necessary for maintaining proper ergosterol levels under azole treatment. Clinical isolates lacking SET1 were also hypersusceptible to azoles which is attributed to reduced ERG11 expression but not defects in drug efflux. Overall, Set1 contributes to azole susceptibility in a species-specific manner by altering the expression and consequently disrupting pathways known for mediating drug resistance.
Project description:Diutina catenulata is an ascomycetous yeast, that is regularly fluconazole-resistant and increasingly reported as the cause of invasive infection in humans. Here, we describe the de novo genome assembly of the clinical D. catenulata type-strain CBS565 and provide insights into the genome and compared it to an Illumina-sequenced environmental strain.
