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.
2017-05-25 | GSE98986 | GEO
Project description:Loss of sterol demethylase activity reduces both azole and echinocandin antifungal susceptibility in a clinical isolate of C. parapsilosis
Project description:This SuperSeries is composed of the following subset Series: GSE27405: Transcriptional response of an azole-resistant Candida parapsilosis isolate [fluconazole]. GSE27407: Transcriptional response of an azole-resistant Candida parapsilosis isolate [posaconazole]. GSE27408: Transcriptional response of an azole-resistant Candida parapsilosis isolate [voriconazole]. Refer to individual Series
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.
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: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: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. C. parapsilosis mRNA profiles of wild type (WT) at 37 degree celcius in planktonic growth conditions and ace2-/-, cph2-/-, efg1-/-, czf1-/-, ume6-/-, bcr1-/- and WT in biofilm conditions were generated by deep sequencing, in triplicate, using Illumina HiSeq2000.