Biofilms of the fungal pathogen Candida albicans can form on implanted medical devices and contribute to fungal virulence and are recalcitrant to antifungal therapy. The transcription factor Ume6 directs hyphal cell elongation and thus promotes biofilm formation in C. albicans.
View Article and Find Full Text PDFExtracellular vesicles (EVs) are heterogeneous particles encapsulated with a phospholipid bilayer membrane. EVs have evolved diverse biological functions, serving mainly as prominent mediators and regulators of cell-cell communication. This study investigated whether candidalysin, a key virulence factor in infections, is present within EVs derived from biofilms and retains activity by inducing host immune responses.
View Article and Find Full Text PDFNat Microbiol
April 2025
Since their discovery in 2007, there has been growing awareness of the importance of fungal extracellular vesicles (EVs) for fungal physiology, host-pathogen interactions and virulence. Fungal EVs are nanostructures comprising bilayered membranes and molecules of various types that participate in several pathophysiological processes in fungal biology, including secretion, cellular communication, immunopathogenesis and drug resistance. However, many questions remain regarding the classification of EVs, their cellular origin, passage across the cell wall, experimental models for functional and compositional analyses, production in vitro and in vivo and biomarkers for EVs.
View Article and Find Full Text PDFCandida albicans is the most common cause of life-threatening fungal infection in the developed world but remains a therapeutic challenge. Protein kinases have been rewarding drug targets across diverse indications but remain untapped for antifungal development. Previously, screening kinase inhibitors against C.
View Article and Find Full Text PDFUnlabelled: Screen of mutants from a mannosyltransferase family identified the importance of for biofilm drug resistance and neutrophil evasion. Biochemical analysis of the mutant matrix and cell wall identified alterations in the mannan structures. Resistance and matrix for were restored with delivery of wild-type matrix via extracellular vesicles.
View Article and Find Full Text PDFRecently expanded reports of multidrug-resistant fungal infections underscore the need to develop new and more efficient methods for antifungal drug discovery. A ubiquitous problem in natural product drug discovery campaigns is the rediscovery of known compounds or their relatives; accordingly, we have integrated Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) for structural dereplication and Yeast Chemical Genomics for bioprocess evaluation into a screening platform to identify such compounds early in the screening process. We identified 450 fractions inhibiting and the resistant strains of and among more than 40,000 natural product fractions.
View Article and Find Full Text PDFAntimicrob Agents Chemother
February 2025
is the second most common cause of invasive candidiasis and is widely known to have reduced susceptibility to fluconazole relative to many other spp. Upc2A is a transcription factor that regulates ergosterol biosynthesis gene expression under conditions of sterol stress such as azole drug treatment or hypoxia. Through an microevolution experiment, we found that loss-of-function mutants of the ATF/CREB transcription factor suppresses the fluconazole hyper-susceptibility of the ∆ mutant.
View Article and Find Full Text PDFAntimicrob Agents Chemother
December 2024
Nystatin, a polyene, is one of the oldest antifungal drugs with wide potency. BSG005 is a novel, chemically modified, nystatin-like molecule in development for systemic therapy. We evaluated the pharmacokinetic/pharmacodynamic (PK/PD) relationships and target exposures using invasive pulmonary aspergillosis (IPA) and invasive candidiasis (IC) infection models for BSG005 against common fungal pathogens including , , , and .
View Article and Find Full Text PDFAntimicrob Agents Chemother
November 2024
Only three classes of antifungal drugs are currently in clinical use. Here, we report that derivatives of the malarial drug mefloquine have broad-spectrum antifungal activity including difficult-to-treat molds and endemic fungi. Pharmacokinetic and efficacy studies of NSC-4377 indicate that it penetrates the central nervous system and is active against .
View Article and Find Full Text PDFOnly three classes of antifungal drugs are currently in clinical use. Here, we report that derivatives of the malarial drug mefloquine have broad spectrum antifungal activity including difficult to treat molds and endemic fungi. Pharmacokinetic and efficacy studies of NSC-4377 indicate it penetrates the central nervous system and is active against in vivo.
View Article and Find Full Text PDFAntimicrob Agents Chemother
August 2024
Candida albicans is a commensal of the human microbiota that can form biofilms on implanted medical devices. These biofilms are tolerant to antifungals and to the host immune system. To identify novel genes modulating C.
View Article and Find Full Text PDFBiofilm formation by the fungal pathogen Candida albicans is the basis for its ability to infect medical devices. The metabolic gene ERG251 has been identified as a target of biofilm transcriptional regulator Efg1, and here we report that ERG251 is required for biofilm formation but not conventional free-living planktonic growth. An erg251Δ/Δ mutation impairs biofilm formation in vitro and in an in vivo catheter infection model.
View Article and Find Full Text PDFOpen Forum Infect Dis
March 2024
The epidemiology of invasive aspergillosis (IA) is evolving. To define the patient groups who will most likely benefit from primary or secondary prophylaxis, particularly those whose medical conditions and IA risk change over time, it is helpful to depict patient populations and their risk periods in a temporal visual model. The Sankey approach provides a dynamic figure to understand the risk of IA for various patient populations.
View Article and Find Full Text PDFThe opportunistic fungal pathogen Candida albicans damages host cells via its peptide toxin, candidalysin. Before secretion, candidalysin is embedded in a precursor protein, Ece1, which consists of a signal peptide, the precursor of candidalysin and seven non-candidalysin Ece1 peptides (NCEPs), and is found to be conserved in clinical isolates. Here we show that the Ece1 polyprotein does not resemble the usual precursor structure of peptide toxins.
View Article and Find Full Text PDFAntimicrob Agents Chemother
March 2024
SF001 is a next-generation polyene antifungal drug in development, designed to have increased specificity to fungal ergosterol, which is absent in humans, and decreased binding to cholesterol. SF001 demonstrates long-acting, potent, broad-spectrum fungicidal activity. The goal of the current study was to determine the pharmacodynamic index and target of SF001 in an immunocompromised mouse model of invasive pulmonary aspergillosis against six isolates.
View Article and Find Full Text PDFThe host type I interferon (IFN) pathway is a major signature of inflammation induced by the human fungal pathogen, Candida albicans. However, the molecular mechanism for activating this pathway in the host defence against C. albicans remains unknown.
View Article and Find Full Text PDFAntimicrob Agents Chemother
January 2024
The newly emerged pathogen, , presents a serious threat to public health worldwide. This multidrug-resistant yeast often colonizes and persists on the skin of patients, can easily spread from person to person, and can cause life-threatening systemic infections. New antifungal therapies are therefore urgently needed to limit and control both superficial and systemic infections.
View Article and Find Full Text PDFis a commensal fungus that colonizes the human oral cavity and gastrointestinal tract but also causes mucosal as well as invasive disease. The expression of virulence traits in clinical isolates is heterogeneous and the genetic basis of this heterogeneity is of high interest. The reference strain SC5314 is highly invasive and expresses robust filamentation and biofilm formation relative to many other clinical isolates.
View Article and Find Full Text PDFProlonged infections in immunocompromised individuals may be a source for novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants, particularly when both the immune system and antiviral therapy fail to clear the infection and enable within-host evolution. Here we describe a 486-day case of SARS-CoV-2 infection in an immunocompromised individual. Following monotherapy with the monoclonal antibody Bamlanivimab, the individual's virus acquired resistance, likely via the earliest known occurrence of Spike amino acid variant E484T.
View Article and Find Full Text PDFTriazole antifungals (i.e., fluconazole, itraconazole, voriconazole, posaconazole, and isavuconazole) are commonly used in clinical practice to prevent or treat invasive fungal infections.
View Article and Find Full Text PDFUnlabelled: is a diploid human fungal pathogen that displays significant genomic and phenotypic heterogeneity over a range of virulence traits and in the context of a variety of environmental niches. Here, we show that the effects of Rob1 on biofilm and filamentation virulence traits is dependent on both the specific environmental condition and the clinical strain of . The reference strain SC5314 is a heterozygote with two alleles that differ by a single nucleotide polymorphism at position 946 resulting in a serine or proline containing isoform.
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