Project description:The limited number of antifungals and the emergence of multidrug-resistant Candida auris pose a significant challenge to human medicine. Here, we utilized combinatorial drug therapy as an approach to augment the activity of current azole antifungals against C. auris. We evaluated the fluconazole chemosensitization activity of 1547 FDA-approved drugs and clinical molecules against an azole-resistant strain of C. auris. This led to the discovery that lopinavir, an antiviral drug, is a potent agent capable of sensitizing C. auris to the effect of azole antifungals. At a therapeutically achievable concentration (4-8 µg/ml), lopinavir exhibited potent synergistic interactions with azole drugs, particularly with itraconazole, against C. auris (ΣFICI ranged from 0.05-0.50). The lopinavir/itraconazole combination enhanced the survival rate of C. auris-infected Caenorhabditis elegans by 90% and reduced the fungal burden in infected nematodes by 88.5% (p < 0.05). Moreover, lopinavir enhanced the antifungal activity of itraconazole against other medically important Candida species including C. albicans, C. tropicalis, C. glabrata, C. tropicalis, and C. parapsilosis. Comparative transcriptomic profiling revealed that lopinavir interferes with glucose permeation and ATP synthesis. This compromises the function of the efflux pumps presents in C. auris enhancing sensitivity to azole antifungals, as demonstrated by Nile red efflux assays. This study presents lopinavir as a novel, potent and broad-spectrum azole chemosensitizing agent that warrants further investigation against recalcitrant Candida infections.
Project description:Candida auris is an emerging multidrug-resistant human fungal pathogen often refractory to treatment by all classes of antifungal drugs. Amphotericin B (AmB) is a fungicidal drug that, despite its toxic side effects, remains a drug of choice for the treatment of drug-resistant fungal infections, including those caused by C. auris. However, the molecular mechanisms underlying AmB resistance are poorly understood. In this study, we present data that suggests membrane lipid alterations and chromatin modifications are critical processes that contribute to or cause adaptive AmB resistance in clinical C. auris isolates. To determine the plausible cause of increased AmB resistance, we performed RNA-seq of AmB-resistant and sensitive C. auris isolates. Remarkably, AmB-resistant strains show a pronounced enrichment of genes involved in lipid and ergosterol biosynthesis, adhesion, drug transport as well as chromatin remodeling. The transcriptomics data confirm increased adhesion and reduced lipid membrane permeability of AmB-resistant strains compared to the sensitive isolates. The AmB-resistant strains also display hyper-resistance to cell wall perturbing agents, including congo red, calcofluor white and caffeine. Additionally, we noticed an increased phosphorylation of Mkc1 cell integrity MAP kinase upon AmB treatment. Collectively, these data identify differences in the transcriptional landscapes of AmB-resistant vs AmB-senstive isolates, and provide a framework for the mechanistic understanding of AmB resistance in C. auris.
Project description:Candida auris clinical isolate FY279 was exposed to tebuconazole (32μg/ml). Randomly14 adaptors were chosen. 10 adaptors obtained resistance to tebuconazole. These resistant adaptors were sequenced.
Project description:Filamentous cell growth is a vital property of fungal pathogens. The mechanisms of filamentation in the emerging multidrug-resistant fungal pathogen Candida auris are poorly understood. Here, we show that exposure of C. auris to glycerol triggers a rod-like filamentation-competent (RL-FC) phenotype, which forms elongated filamentous cells after a prolonged culture period. Whole-genome sequencing analysis reveals that all RL-FC isolates harbor a mutation in the C2H2 zinc finger transcription factor-encoding gene GFC1 (Gfc1 variants). Deletion of GFC1 leads to an RL-FC phenotype similar to that observed in Gfc1 variants. We further demonstrate that GFC1 mutation causes enhanced fatty acid β-oxidation metabolism and thereby promotes RL-FC/filamentous growth. This regulation is achieved through a Multiple Carbon source Utilizer (Mcu1)-dependent mechanism. Interestingly, both the evolved RL-FC isolates and the gfc1Δ mutant exhibit an enhanced ability to colonize the skin. Our results reveal that glycerol-mediated GFC1 mutations are beneficial during C. auris skin colonization and infection.
Project description:Candida auris has been globally recognized as a multidrug-resistant human fungal pathogen that contributes for the worldwide occurrence of nosocomial outbreaks. It has been reported that C. auris was able to avoid neutrophil attack, suggestive of an impaired innate immune response. Whether C. auris evades the innate immune recognition of BMDM (bone marrow derived macrophage) remains poorly understood, and as for well-known Candida species -C. albicans, it can trigger immune response. To determine whether occurs difference between immune response stimulated by C. auris or C. albicans, we performed mRNA-seq of BMDM stimulated by C. auris or C. albicans.
Project description:Candida auris has emerged as a problematic fungal pathogen associated with high morbidity and mortality. Amphotericin B (AmB) is the most effective antifungal used to treat invasive fungal candidiasis, with resistance rarely observed among clinical isolates. However, C. auris possesses extraordinary resistant profiles against all available antifungal drugs, including AmB. In our pursuit of potential solutions, we conducted a screening of a panel of 727 FDA-approved drugs and identified the proton pump inhibitor lansoprazole (LNP) as a potent enhancer of AmB’s activity against C. auris. LNP also potentiates the antifungal activity of AmB against other medically important species of Candida and Cryptococcus. Our investigations into the mechanism of action unveiled that LNP metabolite(s) interact with a crucial target in the mitochondrial respiratory chain (complex III, known as cytochrome bc1). This interaction increases oxidative stress within fungal cells. Our results demonstrated the critical role of an active respiratory function in the antifungal activity of LNP. Most importantly, LNP restored the efficacy of AmB in an immunocompromised mouse model, resulting in a 1.7-log (~98%) CFU reduction in the burden of C. auris in the kidneys. Our findings strongly advocate for a thorough and comprehensive evaluation of LNP as a cytochrome bc1 inhibitor for combating drug-resistant C. auris infections.
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:<p>Filamentous cell growth is a vital property of fungal pathogens. The mechanisms of filamentation in the emerging multidrug-resistant fungal pathogen Candida auris are poorly understood. Here, we show that exposure of C. auris to glycerol triggers a rod-like filamentation-competent (RL-FC) phenotype, which forms elongated filamentous cells after a prolonged culture period. Whole-genome sequencing analysis reveals that all RL-FC isolates harbor a mutation in the C2H2 zinc finger transcription factor-encoding gene <em>GFC1</em> (Gfc1 variants). Deletion of GFC1 leads to an RL-FC phenotype similar to that observed in Gfc1 variants. We further demonstrate that GFC1 mutation causes enhanced fatty acid β-oxidation metabolism and thereby promotes RL-FC/filamentous growth. This regulation is achieved through a Multiple Carbon source Utilizer (Mcu1)-dependent mechanism. Interestingly, both the evolved RL-FC isolates and the gfc1Δ mutant exhibit an enhanced ability to colonize the skin. Our results reveal that glycerol-mediated GFC1 mutations are beneficial during C. auris skin colonization and infection.</p>