Project description:Azole resistance was induced in vitro by growth of a susceptible C. parapsilosis isolate in the presence of fluconazole. Whole genome microarrays were used to compare the transcriptional response of the fluconazole-resistant and susceptible isolates.
Project description:Azole resistance was induced in vitro by growth of a susceptible C. parapsilosis isolate in the presence of voriconazole. Whole genome microarrays were used to compare the transcriptional response of the voriconizole-resistant and susceptible isolates.
Project description:Azole resistance was induced in vitro by growth of a susceptible C. parapsilosis isolate in the presence of posaconazole. Whole genome microarrays were used to compare the transcriptional response of the posaconazole-resistant and susceptible isolates.
Project description:The present study describes a novel mechanism of antifungal resistance affecting the susceptibility of both the azole and echinocandin antifungals in an azole-resistant isolate from a matched pair of C. parapsilosis isolates obtained from a patient with prosthetic valve endocarditis. Transcriptome analysis indicated differential expression of several genes in the resistant isolate including upregulation of ERG1, ERG2, ERG5, ERG6, ERG11, ERG24, ERG25, ERG27, DAP1 and UPC2, of the ergosterol biosynthesis pathway. Whole genome sequencing revealed a mutation in the ERG3 gene leading to a G111R amino acid substitution in the resistant isolate. Subsequent introduction of this allele in the native ERG3 locus in the susceptible isolate resulted in a fluconazole MIC of >64 mg/ml and a caspofungin MIC of 8 mg/ml. Corresponding allelic replacement of the wildtype allele for the mutant allele in the resistant isolate resulted in a drop in MIC to 1 mg/ml for both fluconazole and caspofungin. Sterol profiles indicated a loss of sterol demethylase activity as a result of this mutation. This work demonstrate that this G111R mutation is wholly responsible for the resistant phenotype in the C. parapsilosis resistant isolate and is the first report of this multidrug resistance mechanism.
Project description:Cerebrospinal fluid (CSF) proteins regulate neurogenesis, homeostasis and participate in active signalling during neuroinflammation. Components of CSF are mostly blood-derived, but partially also secreted from the brain cells. While various birds may represent suitable models for the investigation of adult constitutive neurogenesis, proteomic studies of the avian CSF examined so far solely chicken embryos. On this basis, we explored the proteomic composition of CSF and plasma in adult parrots, budgerigar (Melopsittacus undulatus) and cockatiel (Nymphicus hollandicus) and chickens (Gallus gallus) using liquid chromatography–tandem mass spectrometry (nLC-MS/MS). To overcome the lack of a complete cockatiel genome information, we compared the MS/MS identification success rates after mapping all spectra from all three species against the reference proteomes of three model avian species: chicken, budgerigar and zebra finch. We show highest efficiency (8.8-4.7%) for the closest reference proteome, although part of the proteins (7.2-18%) were mapped only with other references. After filtering the selected datasets, we identified up to 746 proteins represented in the CSF and plasma of chicken, budgerigar and cockatiel. Enrichment analysis of the core proteome of these datasets revealed various metabolic and signalling pathways. Comparative analysis of CSF and plasma for each species then indicated clusters of proteins preferentially upregulated into CSF that were involved in neurogenesis, neural development and neural differentiation pathways. This study provides the first insight into the proteomics of adult avian CSF and plasma and brings novel molecular evidence supporting the adult neurogenesis in birds.