Project description:By searching for new drugs against fungal pathogens, we found that miltefosine is active against Aspergillus fumigatus clinical isolates. A library of transcription factors (TF) null mutants was then challenged with this drug and we discovered a novel TF that confers resistance to miltefonise, named here SmiA. By using ChIP-seq, we searched for SmiA targets upon miltefosine treatment.
Project description:To understand how metabolic and nutritional factors governing adaptation to the host niche contribute to the virulence of Aspergillus fumigatus we compared transcriptomes of developmentally matched A.fumigatus isolates following laboratory culture or initiation of infection in the neutropenic murine lung.
Project description:The on-going Microbial Observatory Experiments on the International Space Station (ISS) revealed the presence of various microorganisms that may be affected by the distinct environment of the ISS. The low-nutrient environment combined with enhanced irradiation and microgravity may trigger changes in the molecular suit of microorganisms leading to increased virulence and resistance of microbes. Proteomic characterization of two Aspergillus fumigatus strains, ISSFT-021 and IF1SW-F4, isolated from HEPA filter debris and cupola surface of the ISS, respectively, is presented, along with a comparison to experimentally established clinical isolates Af293 and CEA10. In-depth analysis highlights variations in the proteome of both ISS-isolated strains when compared to the clinical strains. Proteins up-regulated in ISS isolates were involved in oxidative stress response, and carbohydrate and secondary metabolism. This report provides insight into possible molecular adaptation of filamentous fungi to the unique ISS environment. Lastly, an attempt was made to elucidate plausible causes of the enhanced virulence of both ISS-isolated A. fumigatus strains.
Project description:Aspergillus fumigatus can cause Invasive Pulmonary Aspergillosis (IPA), the most severe form of Aspergillus-related infections. Fungicidal azoles and fungistatic caspofungin (CAS) are the first- and second-line therapies, respectively, used to treat IPA. However, azole-resistance is on the rise and new therapeutic alternatives need to be implemented. Recently, we showed that treatment of A. fumigatus with CAS or micafungin, but not voriconazole, induces production of the oxylipin 5,8-diHODE by the fungal oxygenase PpoA. Here we investigated the influence of ppo genes, that encode fatty acid oxygenases responsible for oxylipin biosynthesis, on CAS tolerance. The ppo mutants showed a very complex pattern of CAS susceptibility. PpoA and PpoC influence on CAS tolerance is mediated by MpkA phosphorylation and protein kinase A (PKA) activity. RNAseq transcriptional profiling and label-free quantitative proteomics (spectral counts) of the ppoA, and ppoC mutants showed that differentially expressed genes and proteins are related to secondary metabolites and carbohydrate metabolism. We tested several mutants of these differentially expressed genes encoding transcription factors and signal transduction proteins and some of them are more susceptible to CAS. We also characterized two clinical isolates, CNM7555 and IFM41607, that have decreased and increased susceptibility to CAS. CNM7555 does not have increased oxylipin production in the presence of CAS while the oxylipin induction upon CAS exposure is increased in the IFM41607, suggesting oxylipins are not the single mechanism involved in CAS tolerance in these isolates. Upon CAS exposure, CNM7555 has increased MpkA phosphorylation and PKA activity than IFM41607. Modulation of secondary metabolite production and carbohydrate metabolism is also essential in these clinical isolates for acquiring CAS tolerance. Our results reveal different aspects and genetic determinants involved in A. fumigatus CAS tolerance.
Project description:We compared multiple strains of lab trophozoites to recent clinical isolates. Clinical isolates were grown in xenic media, and maintained many characteristics of the cyst stage of devlopment Keywords: Stage conversion
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.