Project description:In the last decade, Candida krusei has caused multiple outbreaks of candidemia in Neonatal Intensive Care Units (NICUs) in low-and middle-income countries such as Brazil, India, and South Africa. In India, C. krusei ranks as the sixth cause of candidemia in adult ICUs. Additionally, sporadic outbreaks of nosocomial candidemia in the NICUs are widely reported from India. However, the genetic population of C. krusei causing outbreaks remain largely unknown. In the present study, we used whole genome sequencing to examine the genetic structure of C. krusei population causing candidemia spanning a period of five years (2015-20) in a single NICU in Delhi, India. Further, to evaluate the mechanisms of azole antifungal resistance in C. krusei, we compare the transcriptomic profiles of fluconazole susceptible (FLU-S) and resistant (FLU-R) isolates. Transcriptomic assay was performed in logarithmically growing C. krusei clinical isolates 123/P/19 and 1390/P/18 strains. STAR aligner v.2.5.2b was used to sequence the trimmed reads with the specified reference genome of P. kudriavzevii to determine the unique gene hit counts. A total of 178 genes were differentially expressed by at least 1.5-fold in 1390/P/18 as compared to 123/P/19 isolate. Principal component analysis (PCA) of normalized read counts also depicted almost similar transcriptomic profile between the two C. krusei strains with 53 % variance at principal component 1. Out of 178 differentially expressed genes, 72 were up-regulated and 106 were down-regulated in 1390/P/18 strain compared to 123/P/19 strain. Functionally, genes associated with transport (n=10), mitogen activated protein kinase signaling (MAPK; n=8), transcription factors (TF; n=6) and ergosterol biosynthesis (n=3) were expressed differentially.
Project description:Candida glabrata is a human-associated opportunistic fungal pathogen. It shares its niche with Lactobacillus spp. in the gastrointestinal and vaginal tract. In fact, Lactobacillus species are thought to competitively prevent Candida overgrowth. We investigated the molecular aspects of this antifungal effect by analyzing the interaction of C. glabrata strains with Limosilactobacillus fermentum. From a collection of clinical C. glabrata isolates, we identified strains with different sensitivities to L. fermentum in coculture. We analyzed the variation of their expression pattern to isolate the specific response to L. fermentum. C. glabrata-L. fermentum coculture induced genes associated with ergosterol biosynthesis, weak acid stress, and drug/chemical stress. L. fermentum coculture depleted C. glabrata ergosterol. The reduction of ergosterol was dependent on the Lactobacillus species, even in coculture with different Candida species. We found a similar ergosterol-depleting effect with other lactobacillus strains (Lactobacillus crispatus and Lactobacillus rhamosus) on Candida albicans, Candida tropicalis, and Candida krusei. The addition of ergosterol improved C. glabrata growth in the coculture. Blocking ergosterol synthesis with fluconazole increased the susceptibility against L. fermentum, which was again mitigated by the addition of ergosterol. In accordance, a C. glabrata Derg11 mutant, defective in ergosterol biosynthesis, was highly sensitive to L. fermentum. In conclusion, our analysis indicates an unexpected direct function of ergosterol for C. glabrata proliferation in coculture with L. fermentum.
Project description:we performed mitochondrial proteomic analysis on multiple Candida species (C. albicans, C. glabrata, C. krusei and Candida auris) and analyzed the differentially expressed mitochondrial proteins (DEMPs) between azole-sensitive and azole-resistant Candida species.
Project description:The pathogenic yeast Candida krusei is more distantly related to Candida albicans than clinically relevant CTG-clade Candida species. Its cell wall, a dynamic organelle that is the first point of interaction between pathogen and host, is relatively understudied, and its wall proteome remains unidentified to date. Here, we present an integrated study of the cell wall in C. krusei. Our comparative genomic studies and experimental data indicate that the general structure of the cell wall in C. krusei is similar to Saccharomyces cerevisiae and C. albicans and is comprised of b-1,3-glucan, b-1,6-glucan, chitin, and mannoproteins. However, some pronounced differences with C. albicans walls were observed, for instance, higher mannan and protein levels and altered protein mannosylation patterns. Further, despite absence of proteins with high sequence similarity to Candida adhesins, protein structure modeling identified eleven proteins with similarity to flocculins/adhesins in S. cerevisiae or C. albicans. To obtain a proteomic comparison of biofilm and planktonic cells, C. krusei cells were grown to exponential phase and in static 24-h cultures. Interestingly, the 24-h static cultures of C. krusei yielded formation of floating biofilm (flor) rather than adherence to polystyrene at the bottom. The proteomic analysis of both conditions identified a total of 32 cell wall proteins. In line with a possible role in flor formation, increased abundance of flocculins, in particular Flo110, was observed in the floating biofilm compared to exponential cells. This study is the first to provide a detailed description of the cell wall in C. krusei including its cell wall proteome, and paves the way for further investigations on the importance of flor formation and flocculins in the pathogenesis of C. krusei.
2023-04-25 | MSV000091793 | MassIVE
Project description:Whole genome sequencing of Candida krusei clinical bloodstream isolates
Project description:Comparative analysis of genome wide binding profile of Ncb2 in azole sensitive (AS, Gu4) and azole resistant (AR, Gu5) clinical isolates of Candida albicans. The goal was to study the role of Ncb2 in acquisition of drug resistance by comparing the binding profiles of Ncb2 in both the isolates.
Project description:To investigate the diversity of gene contents of Candida albicans strain by array-based comparative genomic hybridization (array CGH; aCGH). A fluconazole-resistant Candida albicans strain CaLY350 was selected to carry out the comparative genomics microarray. Two-condition experiment, CaLY350 vs.SN152. Biological replicates: 2 control, 2 transfected, independently grown and harvested. One replicate per array.