is a major foodborne pathogen and its antimicrobial resistance (AMR) has been described worldwide. The main objective of this study was to determine the occurrence and AMR of spp. isolated from broilers throughout the supply chain in Valencia, Spain.
View Article and Find Full Text PDFPharmaceuticals (PhCs) are organic contaminants that have been detected in wastewater, surface water, and soils throughout the world. The presence of 10 commonly used PhCs in Spain (azithromycin, benzylpenicillin, citalopram, fluconazole, fluoxetine, ibuprofen, irbesartan, olanzapine, telmisartan, and venlafaxine) was analysed at four wastewater treatment plants, and the changes in their concentrations during treatment were assessed. Although certain some PhCs were degraded in the treated water, their presence in sewage sludge increased in all cases.
View Article and Find Full Text PDFis an opportunistic fungus that is part of the normal microflora commonly found in the human digestive tract and the normal mucosa or skin of healthy individuals. However, in immunocompromised individuals, it becomes a serious health concern and a threat to their lives and is ranked as the leading fungal infection in humans worldwide. As existing treatments for this infection are non-specific or under threat of developing resistance, there is a dire necessity to find new targets for designing specific drugs to defeat this fungus.
View Article and Find Full Text PDFWe have established the chemical structure of (+)-bassianolone (3), the antimicrobial compound precursor of cephalosporolides E and F, and that of the furan metabolite 4 from the entomopathogenic fungus Beauveria bassiana.
View Article and Find Full Text PDFThis work supports the idea that composting can be useful for minimizing the rice straw and sewage sludge environmental impact. Several physical, chemical and microbiological properties of these raw materials were analyzed. The characteristics of the rice straw were complementary to those of the sewage sludge for the application of composting.
View Article and Find Full Text PDFMutagenesis of Candida albicans strain ATCC 26555 with N-methyl-nitro-N-nitrosoguanidine followed by plating on solid yeast nitrogen base-N-acetylglucosamine medium at 37 degrees C yielded colony morphology variants that were characterized as forming smooth colonies, in contrast to the rough colonies formed by the parental strain. One yeast monomorphic mutant, CAL4, was studied in detail. Strain CAL4 is defective in filamentous growth, unable to form hyphae or pseudohyphae in vivo and in vitro.
View Article and Find Full Text PDFThe use of trypsin to break proteins covalently linked to the yeast walls of Candida albicans released approx. 50% of the proteins, but also glucose and N-acetylglucosamine. Analysis by affinity chromatography indicated that glucose and/or N-acetylglucosamine formed part of the same supramolecular complexes with mannoproteins.
View Article and Find Full Text PDFTransglutaminase activity, which forms the interpeptidic cross-link N(epsilon)-(gamma-glutamyl)-lysine, was demonstrated in cell-free extracts of Saccharomyces cerevisiae by incorporation of [(14)C]lysine into an exogenous acceptor, N,N'-dimethylcasein. Higher levels of the activity were present in the cell wall, which also contained endogenous acceptors. The enzyme activity in the wall was inhibited by cystamine, a known inhibitor of transglutaminase, and by EDTA, indicating a cation-dependent activity.
View Article and Find Full Text PDFSaccharomyces cerevisiaepresents two alternative vegetative forms of growth, switching between yeast forms to pseudohyphal forms depending on the specific environmental conditions. To identify genes involved in cell wall morphogenesis, a haploid S. cerevisiae monomorphic mutant, W27, which exhibits pseudohyphal growth in the absence of the normal external signals that induce the formation of filamentous forms, was characterized.
View Article and Find Full Text PDFThe mechanisms of incorporation of two antigens have been determined using a monoclonal antibody (3A10) raised against the material released from the mycelial cell wall by zymolyase digestion and retained on a concanavalin A column. One of the hybridomas secreted an IgG that reacted with two bands in Western blots. Indirect immunofluorescence showed that the antigens were located on the surfaces of mycelial cells, but within the cell walls of yeasts.
View Article and Find Full Text PDFMicrobiology (Reading)
March 1999
In a previous series of experiments six mAbs were obtained against cell wall extracts of Candida albicans ATCC 26555. After several studies only one of them, designated 3H8, has been used to produce a commercial kit for the rapid diagnosis of candidiasis, Bichro-latex albicans (Fomouze Diagnostics). The present study involved the generation and characterization of this mAb as an immunoglobulin G1 which recognizes mannoproteins of high molecular mass present in the C.
View Article and Find Full Text PDFUrea or hot sodium dodecyl sulphate extracted a significant amount of the same proteins from the matrix of the cell wall of the yeast form and mycelial cells of Candida albicans. Gel filtration analysis of the urea-extracted proteins revealed that they occurred in the form of large complexes which were unaffected by up to 8 M urea. Among them, proteins en route to becoming covalently associated within the wall scaffold were identified by their reaction with specific antibodies.
View Article and Find Full Text PDFCell wall regeneration of individual Candida albicans yeast and mycelial protoplasts was studied with confocal and electron microscopy using polyclonal antibodies and lectins. Quantitative measurements of the fluorescence emitted by individual protoplasts during the process of regeneration indicate that chitin is the first polymer to be laid down, whereas beta (1,3)- and beta (1,6)glucan are incorporated at a later stage. Mannoproteins were found on the surface of fresh protoplasts and those newly synthesized were then deposited with time.
View Article and Find Full Text PDFCandida albicans cell wall components were analyzed by ethylenediamine (EDA) treatment. Based on their different solubility properties, the cell wall components produced three fractions (A, B, and C). Fractions B (EDA-soluble, water-insoluble) and C (EDA-insoluble) contained glucan, chitin, and protein in different proportions.
View Article and Find Full Text PDFActivity of the enzyme glutaminyl-peptide--glutamylyl-transferase (EC 2.3.2.
View Article and Find Full Text PDFFive different fractions containing uronic acids associated with protein were isolated from the cytoplasm of the filamentous form of Mucor rouxii. A single fraction was isolated from the cell wall by hot sodium dodecyl sulfate followed by ion exchange column chromatography. Two cytoplasmic entities (peaks I and II) were not adsorbed to DEAE Bio-Gel A.
View Article and Find Full Text PDFIn invasive candidiasis, the identification of Candida organisms in tissue samples or in normally sterile fluids is essential for an accurate diagnosis. Species identification is an important clue for the source of infection and in epidemiological studies. In this article, the authors have tested the value of a new monoclonal antibody (1B12) to detect C albicans in culture by immunofluorescence, and in tissue samples by immunohistochemistry.
View Article and Find Full Text PDFFEMS Microbiol Lett
October 1994
Mild alkaline solutions (beta-elimination), after removing the non-covalently bonded wall materials by hot SDS, released 13% and 26% of remaining wall proteins from mycelial and yeast cells of Candida albicans, respectively. When the beta-elimination was carried out after digestion of the walls with chitinase, four-fold more proteinaceous materials were released from mycelium and a similar amount in yeast walls. The solubilized materials were shown to be highly polydisperse, and endo-glycosidase H reduced their polydispersity and molecular masses, revealing different electrophoretic patterns in yeast and mycelial cell walls.
View Article and Find Full Text PDFMicrobiology (Reading)
July 1994
The organization of the components of the cell wall from Candida albicans was studied by means of sequential treatment with hot SDS, anhydrous ethylenediamine (EDA) and lytic enzymes, followed by chemical and microscopic analyses of the different separated fractions. The EDA-insoluble fraction retained the original morphology of the wall, which was destroyed by beta-glucanase, but not by chitinase treatments. Staining with fluorescent lectins revealed distinct distributions of mannoproteins, glucans and chitin in the wall.
View Article and Find Full Text PDFThe kinectics of incorporation of two precursor mannoproteins into the regenerating cell wall of Candida albicans protoplasts have been followed at 28 degrees C and 37 degrees C using two monoclonal antibodies specific for protein epitopes (MAb 1B12 and 4C12) as probes. Both molecules were secreted from the beginning of the regeneration process, and their incorporation was retarded significantly. Analysis of the secreted materials by Western immunoblotting with MAb 1B12 allowed the identification of two closely migrating bands at apparent Mr higher than 170 kDa and significant amounts of a highly polydisperse material of even greater molecular mass.
View Article and Find Full Text PDFThe mannoprotein components solubilized from the walls of Candida albicans blastoconidia following degradation of the glucan network with beta-glucanase (Zymolyase) have higher molecular masses than their probable precursors present in the supernatant of regenerating protoplasts. It therefore appears that the mannoproteins are released from the walls as part of supramolecular complexes. Immunological analysis using both polyclonal and monoclonal antibodies has demonstrated the probable relationship between molecules found in a mixed membrane preparation, those secreted by regenerating protoplasts, and those present in yeast cell walls.
View Article and Find Full Text PDFWall mannoproteins can be divided into two major groups depending upon their degree of interaction with the structural network: one type interacts by non-covalent bonds while the second group seems covalently bound to other wall components (intrinsic or structural mannoproteins). Cytological and biochemical studies have shown that mannoproteins are distributed randomly throughout cell wall interacting with glucan, chitin and other mannoproteins. Experimental results obtained using regenerating protoplasts have shown that building of the wall occurs in two steps: during the first one the skeleton of chitin is formed retaining protein molecules by non-covalent bonds.
View Article and Find Full Text PDFDifferent techniques released from the wall of Candida albicans mycelial cells high molecular weight mannoprotein materials with different levels of complexity. SDS solubilized among others one protein of 180 kDa which reacted with a monoclonal antibody (MAb) specific of a O-glycosylated protein secreted by regenerating mycelial protoplasts [Elorza et al. (1989) Biochem Biophys Res Commun 162:1118-1125].
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