Search results for "Candida albicans"
showing 10 items of 312 documents
Cloning and characterization of PRB1, a Candida albicans gene encoding a putative novel endoprotease B and factors affecting its expression
2002
Abstract Several cDNA fragments corresponding to transcripts differentially expressed under conditions that favor mycelial growth of Candida albicans were identified by the “differential display” technique. One of these was cloned and used as a probe to rescue the full gene from a genomic library of the fungus. The sequence identified a single, uninterrupted open reading frame of 1395 nucleotides encoding a putative protein of 465 residues and a theoretical molecular weight of 50.3 kDa, present in the genome as a single copy located at chromosome 2 in different strains. The gene product showed high homology with subtilisin-like proteases, mainly PRB1, the vacuolar B protease from Saccharomy…
Soft X-ray tomography of phenotypic switching and the cellular response to antifungal peptoids in Candida albicans.
2009
The opportunistic pathogen Candida albicans can undergo phenotypic switching between a benign, unicellular phenotype and an invasive, multicellular form that causes candidiasis. Increasingly, strains of Candida are becoming resistant to antifungal drugs, making the treatment of candidiasis difficult, especially in immunocompromised or critically ill patients. Consequently, there is a pressing need to develop new drugs that circumvent fungal drug-resistance mechanisms. In this work we used soft X-ray tomography to image the subcellular changes that occur as a consequence of both phenotypic switching and of treating C. albicans with antifungal peptoids, a class of candidate therapeutics unaf…
Molecular cloning and characterization of theCandida albicansUBI3 gene coding for a ubiquitin-hybrid protein
2000
Using a polyubiquitin cDNA as a probe, we have isolated a clone (pPR3, a pEMBLYe23 derivative plasmid) containing the Candida albicans UBI3 gene coding for a fusion protein. This protein is formed by one ubiquitin subunit fused, at its C-terminus, to an unrelated peptide which is similar to the ribosomal protein encoded by the 3' tail of the Saccharomyces cerevisiae UBI3 gene. Southern blot analysis of chromosomal DNA probed with the 3' non-ubiquitin tail of UBI3 indicated that only one homologous gene is present in the C. albicans genome. Heterelogous expression of pPR3 in a S. cerevisiae ubi3 mutant strain complements the mutant phenotype (slow growth) conferred by the ubi3 defect; this p…
Pga26 mediates filamentation and biofilm formation and is required for virulence in Candida albicans
2011
The Candida albicans gene PGA26 encodes a small cell wall protein and is upregulated during de novo wall synthesis in protoplasts. Disruption of PGA26 caused hypersensitivity to cell wall-perturbing compounds (Calcofluor white and Congo red) and to zymolyase, which degrades the cell wall β-1,3-glucan network. However, susceptibility to caspofungin, an inhibitor of β-1,3-glucan synthesis, was decreased. In addition, pga26Δ mutants show increased susceptibility to antifungals (fluconazol, posaconazol or amphotericin B) that target the plasma membrane and have altered sensitivities to environmental (heat, osmotic and oxidative) stresses. Except for a threefold increase in β-1,6-glucan and a sl…
The Candida albicans pH-regulated KER1 gene encodes a lysine/glutamic-acid-rich plasma-membrane protein that is involved in cell aggregation.
2004
Immunoscreening of aCandida albicanscDNA library with a polyclonal germ-tube-specific antibody (pAb anti-gt) resulted in the isolation of a gene encoding a lysine/glutamic-acid-rich protein, which was consequently designatedKER1. The nucleotide and deduced amino acid sequences of this gene displayed no significant homology with any other known sequence.KER1encodes a 134 kDa lysine (14·5 %)/glutamic acid (16·7 %) protein (Ker1p) that contains two potential transmembrane segments.KER1was expressed in a pH-conditional manner, with maximal expression at alkaline pH and lower expression at pH 4·0, and was regulated byRIM101. A Δker1/Δker1null mutant grew normally but was hyperflocculant under ge…
Signalling through TLR2/MyD88 induces differentiation of murine bone marrow stem and progenitor cells to functional phagocytes in response to Candida…
2009
Summary We have previously demonstrated that inactivated yeasts and hyphae of Candida albicans induce in vitro the proliferation of murine haematopoietic stem and progenitor cells (HSPCs, sorted as LKS cells: Lin - c-Kit + Sca-1 + ) as well as their differentia- tion to lineage-positive cells, through a MyD88- dependent pathway. In this work, we have found that this process is mainly mediated by TLR2, and that expanding cells express myeloid and not lym- phoid markers. Incubation of long-term repopulat- ing HSCs (Lin - CD105 + and Sca-1 + ) with C. albicans yeasts resulted in their proliferation and up regu- lation of the common myeloid progenitors (CMPs) markers, CD34 and FcgRII/III, by a …
The loss of the inducible Aspergillus carbonarius MFS transporter MfsA leads to ochratoxin A overproduction
2014
Ochratoxin A (OTA), a nephrotoxic compound produced by certain Aspergillus and Penicillium species, is one of the most abundant mycotoxins in food commodities. Aspergillus carbonarius is the main source of OTA in wine, grape juice and dried vine fruits. Although many studies have focused on OTA production by A. carbonarius, little is known about the genes related to OTA production and transport. We have found a transporter that belongs to the major facilitator superfamily (MfsA) which is highly expressed with a 102-fold induction in an ochratoxigenic A. carbonarius strain compared to a low OTA producer strain. The encoding mfsA gene shows similarity to the multidrug efflux transporter flu1 …
MALIGNANT TUMOR-LIKE GAASTRIC LESION DUE TO CANDIDA ALBICANS IN A DIABETIC PATIENT TREATED WITH CYCLOSPORIN: A CASE REPORT AND REVIEW OF THE LITERATU…
2012
The gastrointestinal tract of healthy individuals is colonized by hundreds of saprophytes and mycetes, especially the Candida species, are habitual ones. Under certain conditions, the fungal flora may overgrow, resulting in lesions of the digestive mucosa which, rarely, can have a local diffusion and/or spread to the lympho-hematogenous system. Mycotic infections of the stomach can sometimes look like benign gastric ulcers. Here, we present the case report of a woman, aged 64, who presented with type II diabetes mellitus and psoriasis, on chronic treatment with cyclosporin A and with endoscopic evidence of an ulcerated, vegetating gastric lesion secondary to Candida albicans infection. Alth…
Identification of pH-regulated antigen 1 released from Candida albicans as the major ligand for leukocyte integrin alphaMbeta2.
2007
Candida albicans is a common opportunistic fungal pathogen and is the leading cause of invasive fungal disease in immunocompromised individuals. The induction of cell-mediated immunity to C. albicans is of critical importance in host defense and the prime task of cells of the innate immune system. We previously demonstrated that the integrin alpha(M)beta(2) (CD11b/CD18) is the major leukocyte receptor involved in C. albicans recognition, mediating both adhesive and migratory responses to the fungus. In the present study, we demonstrate that various C. albicans strains release a protease-sensitive activity into their conditioned medium that supports alpha(M)beta(2)-mediated cell adhesion and…
Isolation and identification of the antibacterial compounds from Helichrysum stoechas.
1991
Fractionation of the dicholoromethane extract of the aerial parts of Helichrysum stoechas yielded seven isolates (1-7), which exhibited varying antimicrobial activity against Gram-positive bacteria. Pure compounds 1-3 have been previously reported in the same species and 4 and 5 were identified as italipyrone and plicatipyrone, previously isolated from H. italicum and H. plicatum. The two other isolates are helipyrone (6) and homoarenol (7) mixed with related substances. Compound 6c (4,4'-dihydroxy-5,6,5',6'-tetramethyl-3,3'-methylen-di-pyr-2-one) and 6b helipyrone with one methyl substitution, have not been previously reported in other species.