Zosteric acid (ZA) is a secondary metabolite of the seagrass with antibiofilm activity against fungi. Information concerning its mechanisms of action is lacking and this limits the development of more potent derivatives based on the same target and activity structure. The aim of this work was to investigate the ZA mode of action by analyzing the metabolic status of biofilm and its protein expression profile upon ZA treatment.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
September 2021
Antimicrobial Polyvinyl chloride (PVC) was obtained by covalent bonding of zinc oxide nanoparticles, which have gained important achievements in antimicrobial fields because of their auspicious properties. This was achieved by grafting mercaptopropyltrimethoxysilane onto PVC, followed by the growth of zinc oxide nanoparticles covalently bonded on the polymer surface. In this study, the relationship between the physicochemical features of modified-surface PVC and antimicrobial activity on Staphylococcus aureus and Candida albicans was investigated.
View Article and Find Full Text PDFRibosomal RNA in fungi is encoded by a series of genes and spacers included in a large operon present in 100 tandem repeats, normally in a single locus. The multigene nature of this locus was somehow masked by Sanger sequencing, which produces a single sequence reporting the prevalent nucleotide of each site. The introduction of next generation sequencing led to deeper knowledge of the individual sequences (reads) and therefore of the variants between the same DNA sequences located in different tandem repeats.
View Article and Find Full Text PDFYeast taxonomy was introduced based on the idea that physiological properties would help discriminate species, thus assuming a strong link between physiology and taxonomy. However, the instability of physiological characteristics within species configured them as not ideal markers for species delimitation, shading the importance of physiology and paving the way to the DNA-based taxonomy. The hypothesis of reconnecting taxonomy with specific traits from phylogenies has been successfully explored for Bacteria and Archaea, suggesting that a similar route can be traveled for yeasts.
View Article and Find Full Text PDFIn yeast engineering, metabolic burden is often linked to the reprogramming of resources from regular cellular activities to guarantee recombinant protein(s) production. Therefore, growth parameters can be significantly influenced. Two recombinant strains, previously developed by the multiple δ-integration of a glucoamylase in the industrial 27P, did not display any detectable metabolic burden.
View Article and Find Full Text PDFIn the lignocellulosic yeast development, metabolic burden relates to redirection of resources from regular cellular activities toward the needs created by recombinant protein production. As a result, growth parameters may be greatly affected. Noteworthy, M2n[pBKD2-]-C1, previously developed by multiple δ-integration of the β-glucosidase , did not show any detectable metabolic burden.
View Article and Find Full Text PDFA correct, fast, reliable identification method is pivotal in nosocomial environments to guide treatment strategies, whereas misidentification might lead to treatment failure. For routine identifications the Vitek system and CHROMagar are widely used but not always reliable, especially now with an increasing number of new emerging fungal pathogens that need careful identification. Here we describe two cases of candidemia, due to Candida palmioleophila previously misidentified as Candida albicans by using the Vitek2 system and CHROMagar.
View Article and Find Full Text PDFCandida parapsilosis is an emerging opportunistic pathogen present in both clinical and natural environment, with a strong frequency of biofilm forming strains. While the drugs active against biofilm are rare, liposomal amphotericin B is credited with an antibiofilm activity in some opportunistic species of the genus Candida. Using freshly isolated strains from hospital environment, in this paper we could show the prevalence of biofilm forming vs.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
November 2019
Tuberculins purified protein derivatives (PPDs) are obtained by precipitation from heat treated mycobacteria. PPDs are used in diagnosis of mycobacterial infections in humans and animals. Bovine PPD (PPDB) is obtained from ( complex), while Avian PPD (PPDA) and Johnin PPD (PPDJ) are extracted, respectively, from and ( complex).
View Article and Find Full Text PDFMicrobes growing onto solid surfaces form complex 3-D biofilm structures characterized by the production of extracellular polymeric compounds and an increased resistance to drugs. The quantification of biofilm relays currently on a number of different approaches and techniques, often leading to different evaluations of the ability to form biofilms of the studied microbial strains. Measures of biofilm biomass were carried out with crystal violet (CV) and a direct reading at 405 nm, whereas the activity was assessed with the XTT ((2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2-tetrazolium-5-carboxanilide) method.
View Article and Find Full Text PDFLignocellulosic bioethanol production results in huge amounts of stillage, a potentially polluting by-product. Stillage, rich in heavy metals and, mainly, inhibitors, requires specific toxicity studies to be adequately managed. To this purpose, we applied an FTIR ecotoxicological bioassay to evaluate the toxicity of lignocellulosic stillage.
View Article and Find Full Text PDFA procedure for microbial cell density determination with a high-throughput densitometric assay was developed to allow a precise quantification of both free and sessile cells, such as those of a biofilm, with a large range from low to high cell densities. Densitometry was chosen because it allows fast, rapid and cost-effective measures; it is non-disruptive; and has an easy learning curve. The method setup, and the further validation, was carried out with strains of and Equations were developed at the level of the single strains, of the three species and finally a general one applicable to all three species.
View Article and Find Full Text PDFA yeast strain was isolated during a study on vineyard-associated yeast strains from Apulia in Southern Italy. ITS and LSU D1/D2 rDNA sequences showed this strain not to belong to any known species and was described as the type strain of , a close relative of . Several secondary peaks appeared in the sequences, suggesting internal heterogeneity among the copies of the rDNA.
View Article and Find Full Text PDFSpecies identification of yeasts and other Fungi is currently carried out with Sanger sequences of selected molecular markers, mainly from the ribosomal DNA operon, characterized by hundreds of tandem repeats of the 18S, ITS1, 5.8S, ITS2 and LSU . The ITS region has been recently proposed as a primary barcode marker making this region the most used one in taxonomy, phylogeny and diagnostics.
View Article and Find Full Text PDFMedical and environmental microbiology have two distinct, although very short, histories stemming, the first from the pioneering works of Sommelweiss, Pasteur, Lister and Koch, the second mainly from the studies of Bejerink and Winogradsky. These two branches of microbiology evolved and specialized separately producing distinct communities and evolving rather different approaches and techniques. The evidence accumulated in recent decades indicate that indeed most of the medically relevant microorganisms have a short circulation within the nosocomial environment and a larger one involving the external, i.
View Article and Find Full Text PDFThe rapid and accurate identification of pathogen yeast species is crucial for clinical diagnosis due to the high level of mortality and morbidity induced, even after antifungal therapy. For this purpose, new rapid, high-throughput and reliable identification methods are required. In this work we described a combined approach based on two high-throughput techniques in order to improve the identification of pathogenic yeast strains.
View Article and Find Full Text PDFMechanical mapping with chemical specificity of biological samples is now made possible by joint micro-Brillouin and micro-Raman measurements. In this work, thanks to the unprecedented contrast of a new tandem Fabry-Perot interferometer, we demonstrate simultaneous detection of Brillouin and Raman spectra from different Candida biofilms. Our proof-of-concept study reveals the potential of this label-free joint micro-spectroscopy technique in challenging microbiological issues.
View Article and Find Full Text PDFThe etiology and pathogenesis of Parkinson's disease (PD) are still unclear. However, multiple lines of evidence suggest a critical role of the toll like receptor 4 (TLR4) in inflammatory response and neuronal death. Neuroinflammation may be associated with the misfolding and aggregation of proteins accompanied by a change in their secondary structure.
View Article and Find Full Text PDFTwo hundred seventy seven strains from eleven opportunistic species of the genus Candida, isolated from two Italian hospitals, were identified and analyzed for their ability to form biofilm in laboratory conditions. The majority of Candida albicans strains formed biofilm while among the NCAC species there were different level of biofilm forming ability, in accordance with the current literature. The relation between the variables considered, i.
View Article and Find Full Text PDFThe aim of this study was to assess potential candidate gene regions and corresponding universal primer pairs as secondary DNA barcodes for the fungal kingdom, additional to ITS rDNA as primary barcode. Amplification efficiencies of 14 (partially) universal primer pairs targeting eight genetic markers were tested across > 1 500 species (1 931 strains or specimens) and the outcomes of almost twenty thousand (19 577) polymerase chain reactions were evaluated. We tested several well-known primer pairs that amplify: i) sections of the nuclear ribosomal RNA gene large subunit (D1-D2 domains of 26/28S); ii) the complete internal transcribed spacer region (ITS1/2); iii) partial β -tubulin II (TUB2); iv) γ-actin (ACT); v) translation elongation factor 1-α (TEF1α); and vi) the second largest subunit of RNA-polymerase II (partial RPB2, section 5-6).
View Article and Find Full Text PDFZwitterionic sulfobetaine surfactants are used in pharmaceutical or biomedical applications for the solubilization and delivery of hydrophobic molecules in aqueous medium or in biological environments. In a screening on the biocidal activity of synthetic surfactants on microbial cells, remarkable results have emerged with sulfobetaine amphiphiles. The interaction between eight zwitterionic sulfobetaine amphiphiles and Saccharomyces cerevisiae model cells was therefore analyzed.
View Article and Find Full Text PDFBackground: Trichoderma species are saprophytic filamentous fungi producing localized and invasive infections that are cause of morbidity and mortality, especially in immunocompromised patients, causing up to 53% mortality. Non-immunocompromised patients, undergoing continuous ambulatory peritoneal dialysis, are other targets of this fungus. Current molecular diagnostic tools, based on the barcode marker ITS, fail to discriminate these fungi at the species level, further increasing the difficulty associated with these infections and their generally poor prognosis.
View Article and Find Full Text PDFExperiencing an adverse childhood and parental neglect is a risk factor for depression in the adult population. Patients with a history of traumatic childhood develop a subtype of depression that is characterized by earlier onset, poor treatment response and more severe symptoms. The long-lasting molecular mechanisms that are engaged during early traumatic events and determine the risk for depression are poorly understood.
View Article and Find Full Text PDFMeyerozyma guilliermondii is a yeast species widely isolated from several natural environments and from fruit; in medical microbiology it is known as the teleomorph of the opportunistic pathogen Candida guilliermondii, which causes about 2% of the human blood infections. This yeast is also promising in a variety of biotechnological applications as vitamins production and post-harvest control. The question if isolates from different sources are physiologically and genetically similar, or if the various environments induced significant differences, is crucial for the understanding of this species structure and to select strains appropriate for each application.
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