Search results for "Microbio"
showing 10 items of 8741 documents
Jaminaea phylloscopi sp. nov. (Microstromatales), a basidiomycetous yeast isolated from migratory birds in the Mediterranean basin.
2016
During a survey of yeasts vectored by migratory birds in the Mediterranean basin, isolations from the cloacae of members of the order Passeriformes collected in Ustica (Italy) were performed. Based on phylogenetic analysis of the D1/D2 domain of the 26S rRNA gene and the internal transcribed spacer ITS1-5.8S rRNA gene-ITS2 region, five yeast isolates clustered in a new lineage within the Microstromatales clade. The DNA sequences of these isolates differed from those of their closest relatives, Jaminaea angkorensis and Jaminaea lanaiensis, by 20 and 25 nt substitutions in the D1/D2 domain and 119 and 131 nt substitutions in the complete ITS region, respectively. In addition, the five isolate…
Mycobacterium tuberculosis complex lineage 5 exhibits high levels of within-lineage genomic diversity and differing gene content compared to the type…
2021
Pathogens of theMycobacterium tuberculosiscomplex (MTBC) are considered to be monomorphic, with little gene content variation between strains. Nevertheless, several genotypic and phenotypic factors separate strains of the different MTBC lineages (L), especially L5 and L6 (traditionally termedMycobacterium africanum) strains, from each other. However, this genome variability and gene content, especially of L5 strains, has not been fully explored and may be important for pathobiology and current approaches for genomic analysis of MTBC strains, including transmission studies. By comparing the genomes of 355 L5 clinical strains (including 3 complete genomes and 352 Illumina whole-genome sequenc…
Host-based lipid inflammation drives pathogenesis in Francisella infection
2017
Mass spectrometry imaging (MSI) was used to elucidate host lipids involved in the inflammatory signaling pathway generated at the host-pathogen interface during a septic bacterial infection. Using Francisella novicida as a model organism, a bacterial lipid virulence factor (endotoxin) was imaged and identified along with host phospholipids involved in the splenic response in murine tissues. Here, we demonstrate detection and distribution of endotoxin in a lethal murine F. novicida infection model, in addition to determining the temporally and spatially resolved innate lipid inflammatory response in both 2D and 3D renderings using MSI. Further, we show that the cyclooxygenase-2-dependent lip…
Role of Microbiota-Derived Extracellular Vesicles in Gut-Brain Communication
2021
Human intestinal microbiota comprise of a dynamic population of bacterial species and other microorganisms with the capacity to interact with the rest of the organism and strongly influence the host during homeostasis and disease. Commensal and pathogenic bacteria coexist in homeostasis with the intestinal epithelium and the gastrointestinal tract’s immune system, or GALT (gut-associated lymphoid tissue), of the host. However, a disruption to this homeostasis or dysbiosis by different factors (e.g., stress, diet, use of antibiotics, age, inflammatory processes) can cause brain dysfunction given the communication between the gut and brain. Recently, extracellular vesicles (EVs) derived from …
Molecular characterisation, evolution and expression analysis of g-type lysozymes in Ciona intestinalis
2017
Lysozyme is an important defense molecule of the innate immune system. Known for its bactericidal properties, lysozyme catalyzes the hydrolysis of b-(1,4)-glycosidic bonds between the N-acetyl glucosamine and N-acetyl muramic acid in the peptidoglycan layer of bacterial cell walls. In this study, the complete coding sequence of four g-type lysozymes were identified in Ciona intestinalis. Phylogenetic analysis and modelling supported the hypothesis of a close relationship with the vertebrate g-type lysozymes suggesting that the C. intestinalis g-type lysozyme genes (CiLys-g1, Cilys-g2, CiLys-g3, CiLys-g4) share a common ancestor in the chordate lineage. Protein motif searches indicated that …
The Complete Structure of the Core Oligosaccharide from Edwardsiella tarda EIB 202 Lipopolysaccharide
2017
The chemical structure and genomics of the lipopolysaccharide (LPS) core oligosaccharide of pathogenic Edwardsiella tarda strain EIB 202 were studied for the first time. The complete gene assignment for all LPS core biosynthesis gene functions was acquired. The complete structure of core oligosaccharide was investigated by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry MSn, and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry. The following structure of the undecasaccharide was established: The heterogeneous appearance of the core oligosaccharide structure was due to the partial lack of β-d-Galp and the replace…
Decreasing role of HCV and HBV infections as aetiological factors of hepatocellular carcinoma in Italy
2019
Background: The epidemiology of hepatocellular carcinoma (HCC) is characterized by a dynamical temporal trend of well-established and emerging risk factors. Methods: We evaluated the temporal trend of aetiological factors of HCC over the last two decades in Italy. HCC cases were recruited from two previously published national studies in 1996 and in 2008 and HCC cases were also enlisted from two national surveys in 2001 and in 2014 enrolling consecutive subjects with chronic liver disease (CLD) referring to more than 80 liver units scattered all over the country for a 6-monthperiod. Results: Out of the 9997 subjects with CLD recruited in 2001 and the 2408 recruited in 2014, 3.3% and 5.7% (P…
The impact of cooking on meat microstructure studied by low field NMR and Neutron Tomography
2017
International audience; We studied the impact of temperature of cooking on meat microstructure. The cooking temperature was verified by calorimetry, showing the disappearance of endothermic peaks when cooking temperature was increased. These observations correspond to the denaturation of different protein fractions at specific temperatures. 1H-low field NMR and neutron tomography were used to further understand the relationship between the observed protein denaturation and changes in meat microstructure after heating. Hahn’s echo and solid echo NMR sequences were applied to observe fast relaxation time corresponding to rigid protons. These protons were found to be associated with pools of p…
Cytotoxic activity of Holothuria tubulosa (Echinodermata) coelomocytes.
2017
Abstract The immune system of marine invertebrates, in particular that of holothurians, still requires further study. Our research showed that coelomocyte cells contained in the coelomic fluid of the sea cucumber, Holothuria tubulosa, are able to lyse, in vitro, red blood cells in rabbits and sheep. A plaque-forming assay showed spherule cells to be the effector cells, able to release cytotoxic molecules after xenogenic cell contact. The coelomocyte lysate supernatant, analysed by polyacrylamide gel electrophoresis overlay technique, using rabbit and sheep erythrocytes, showed two different haemolytic protein patterns: one calcium dependent and the other calcium independent. The fractions o…
Mycobacterium tuberculosis Rv2145c Promotes Intracellular Survival by STAT3 and IL-10 Receptor Signaling
2021
Although Mycobacterium tuberculosis (Mtb) is an intracellular pathogen in phagocytic cells, the factors and mechanisms by which they invade and persist in host cells are still not well understood. Characterization of the bacterial proteins modulating macrophage function is essential for understanding tuberculosis pathogenesis and bacterial virulence. Here we investigated the pathogenic role of the Rv2145c protein in stimulating IL-10 production. We first found that recombinant Rv2145c stimulated bone marrow-derived macrophages (BMDMs) to secrete IL-10, IL-6 and TNF-α but not IL-12p70 and to increase the expression of surface molecules through the MAPK, NF-κB, and TLR4 pathways and enhanced …