Search results for "Microbio"
showing 10 items of 8741 documents
Distinctive attributes for predicted secondary structures at terminal sequences of non-classically secreted proteins from proteobacteria
2008
Abstract C- and N-terminal sequences (64 amino acid residues each) of 89 non-classically secreted type I, type III and type IV proteins (Swiss-Prot/TrEMBL) from proteobacteria were transformed into predicted secondary structures. Multivariate analysis of variance (MANOVA) confirmed the significance of location (C- or N-termini) and secretion type as essential factors in respect of quantitative representations of structured (a-helices, b-strands) and unstructured (coils) elements. The profiles of secondary structures were transcripted using unequal property values for helices, strands and coils and corresponding numerical vectors (independent variables) were subjected to multiple discriminan…
Production and Properties of Starch Citrates—Current Research
2020
Starch modification by chemical reaction is widely used to improve the properties of native starch. Modified by citric acid, starch is characterized by specific properties resulting from the presence of citrate residues and as a result of cross-linking starch. The chemicals used for preparing starch citrates are safe for human health and the natural environment compared to the harsh chemicals used for conventional modifications. Starch citrates are traditionally produced by heating starch–citric acid mixtures in semi-dry conditions or by a heat moisture treatment. The conditions of the modification process (roasting temperature, heating time, citric acid dose) and the botanic source or geno…
Thiazole Analogues of the Marine Alkaloid Nortopsentin as Inhibitors of Bacterial Biofilm Formation
2020
Anti-virulence strategy is currently considered a promising approach to overcome the global threat of the antibiotic resistance. Among different bacterial virulence factors, the biofilm formation is recognized as one of the most relevant. Considering the high and growing percentage of multi-drug resistant infections that are biofilm-mediated, new therapeutic agents capable of counteracting the formation of biofilms are urgently required. In this scenario, a new series of 18 thiazole derivatives was efficiently synthesized and evaluated for its ability to inhibit biofilm formation against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 25923 and S. aureus ATCC 6538 a…
An extended catalogue of ncRNAs in Streptomyces coelicolor reporting abundant tmRNA, RNase-P RNA and RNA fragments derived from pre-ribosomal RNA lea…
2022
Streptomyces coelicolor is a model organism for studying streptomycetes. This genus possesses relevant medical and economical roles, because it produces many biologically active metabolites of pharmaceutical interest, including the majority of commercialized antibiotics. In this bioinformatic study, the transcriptome of S. coelicolor has been analyzed to identify novel RNA species and quantify the expression of both annotated and novel transcripts in solid and liquid growth medium cultures at different times. The major characteristics disclosed in this study are: (i) the diffuse antisense transcription; (ii) the great abundance of transfer-messenger RNAs (tmRNA); (iii) the abundance of rnpB…
Single-cell analysis of population context advances RNAi screening at multiple levels
2012
Isogenic cells in culture show strong variability, which arises from dynamic adaptations to the microenvironment of individual cells. Here we study the influence of the cell population context, which determines a single cell's microenvironment, in image‐based RNAi screens. We developed a comprehensive computational approach that employs Bayesian and multivariate methods at the single‐cell level. We applied these methods to 45 RNA interference screens of various sizes, including 7 druggable genome and 2 genome‐wide screens, analysing 17 different mammalian virus infections and four related cell physiological processes. Analysing cell‐based screens at this depth reveals widespread RNAi‐induce…
Toll Like Receptors as Sensors of the Tumor Microbial Dysbiosis: Implications in Cancer Progression
2021
Microbiota is a complex ecosystem of active microorganisms resident in the body of mammals. Although the majority of these microorganisms resides at the distal gastrointestinal tract, high-throughput DNA sequencing technology have made possible to understand that several other tissues of the human body host their own microbiota, even those once considered sterile, such as lung tissue. These bacterial communities have important functions in maintaining a healthy body state and the host immune system has evolved multiple mechanisms by which maintaining a symbiotic relationship with the microbiota. The maintenance of this dialogue allows the induction of protective responses to pathogens and r…
Role of hematopoietic stem and progenitor cells in training immunity against infection
2022
During an infection, haematopoiesis is altered to increase the output of mature myeloid cells to fight off the pathogen. It has been demonstrated that the detection of pattern recognition receptor agonists by hematopoietic stem and progenitor cells (HSPCs) induces their differentiation towards mature myeloid cells with modified phenotypes. In the present PhD thesis, we show that an in vitro transient exposure of HSPCs to live Candida albicans cells is sufficient to induce a trained phenotype of the macrophages they produce in a dectin-1- and TLR2-dependent manner. Additionally, we use an HSPC transplantation mouse model to demonstrate that the direct interaction of β-glucans and their recep…
The LuxR Regulators PcoR and RfiA Co-regulate Antimicrobial Peptide and Alginate Production in
2017
Cyclic lipopeptides (CLPs) are considered as some of the most important secondary metabolites in different plant-associated bacteria, thanks to their antimicrobial, cytotoxic, and surfactant properties. In this study, our aim was to investigate the role of the Quorum Sensing (QS) system, PcoI/PcoR, and the LuxR-type transcriptional regulator RfiA in CLP production in the phytopatogenic bacterium, Pseudomonas corrugata based on our previous work where we reported that the pcoR and rfiA mutants were devoid of the CLPs cormycin and corpeptin production. Due to the close genetic link between the QS system and the RfiA (rfiA is co-transcribed with pcoI), it was difficult to ascertain the specifi…
Evolutionary advantage conferred by an eukaryote-to-eukaryote gene transfer event in wine yeasts
2015
Although an increasing number of horizontal gene transfers have been reported in eukaryotes, experimental evidence for their adaptive value is lacking. Here, we report the recent transfer of a 158-kb genomic region between Torulaspora microellipsoides and Saccharomyces cerevisiae wine yeasts or closely related strains. This genomic region has undergone several rearrangements in S. cerevisiae strains, including gene loss and gene conversion between two tandemly duplicated FOT genes encoding oligopeptide transporters. We show that FOT genes confer a strong competitive advantage during grape must fermentation by increasing the number and diversity of oligopeptides that yeast can utilize as a s…
Double copies of blaKPC-3::Tn4401a on an IncX3 plasmid in Klebsiella pneumoniae successful clone ST512 from Italy
2015
ABSTRACT A carbapenem-resistant sequence type 512 (ST512) Klebsiella pneumoniae carbapenemase 3 (KPC-3)-producing K. pneumoniae strain showing a novel variant plasmid content was isolated in Palermo, Italy, in 2014. ST512 is a worldwide successful clone associated with the spread of bla KPC genes located on the IncFIIk pKpQIL plasmid. In our ST512 strain, the bla KPC-3 gene was unusually located on an IncX3 plasmid, whose complete sequence was determined. Two copies of bla KPC-3 ::Tn 4401a caused by intramolecular transposition events were detected in the plasmid.