Search results for "microbial"
showing 10 items of 2041 documents
Identification, cloning and environmental factors modulation of a αβ defensin from the lessepsian invasive mussel Brachidontes pharaonis (Bivalvia: M…
2015
International audience; Immunological effectors of invasive species playing a role in addressing new colonization are still poorly studied. In the present study the cDNA sequence of the defensin from a Lessepsian invasive species, the Red Sea mussel Brachidontes pharaonis, was cloned using RACE method. Defensins are a class of widely known antimicrobial peptides (AMPs), oligopeptides with a broad spectrum of targeted organisms ranging from viruses to parasites. Analysis of BpDef sequence (262 bp) revealed the presence of an ORF coding for 81 amino acids. The full-length amino acid sequence showed the highest similarity to antimicrobial peptides MGD1 and MGD2 sequence from Mytilus galloprovi…
Monoclonal anti-fosB antibody specific for predetermined, nonstructural region of the fosB protein.
1997
Comparison of the primary structures and theoretical prediction of the potential antigenic determinant of the deduced Fos proteins reveals the presence of a nonstructural and hydrophilic region juxtaposed to the leucine zipper and nonconserved among the Fos protein family. To develop monoclonal anti-peptide antibodies capable of distinguishing all Fos-proteins, synthetic peptides specific for the mentioned predicted region were synthesized manually by the "tea-bag" method. Immunization of Balb/c mice with fosB-related synthetic peptide BSA gave rise to mouse hybridoma cell line K21 (IgG1, kappa) secreting highly specific antibodies against corresponding human fosB protein. Fine mapping of t…
Hybrid sequencing approach applied to human fecal metagenomic clone libraries revealed clones with potential biotechnological applications.
2012
Natural environments represent an incredible source of microbial genetic diversity. Discovery of novel biomolecules involves biotechnological methods that often require the design and implementation of biochemical assays to screen clone libraries. However, when an assay is applied to thousands of clones, one may eventually end up with very few positive clones which, in most of the cases, have to be "domesticated" for downstream characterization and application, and this makes screening both laborious and expensive. The negative clones, which are not considered by the selected assay, may also have biotechnological potential; however, unfortunately they would remain unexplored. Knowledge of t…
A bug's life: Delving into the challenges of helminth microbiome studies.
2020
The body of vertebrates is inhabited by trillions of microorganisms, i.e. viruses, archaea, bacteria and unicellular eukaryotes, together referred to as the ‘microbiota’. Similarly, vertebrates also host a plethora of parasitic worms (the ‘macrobiota’), some of which share their environment with the microbiota inhabiting the gastrointestinal tract [1]. Complex interactions between the helminths and the gut microbiota have been associated with establishment of parasite infection, disease manifestations, and host immune-modulation [2, 3]. Remarkably, not only enteric helminths alter the 26 gut microbiome composition [4], but also the infection with blood flukes of the genus Schistosoma has be…
Excitation-Wavelength-Dependent Photocycle Initiation Dynamics Resolve Heterogeneity in the Photoactive Yellow Protein from Halorhodospira halophila
2018
Photoactive yellow proteins (PYPs) make up a diverse class of blue-light-absorbing bacterial photoreceptors. Electronic excitation of the p-coumaric acid chromophore covalently bound within PYP results in triphasic quenching kinetics; however, the molecular basis of this behavior remains unresolved. Here we explore this question by examining the excitation-wavelength dependence of the photodynamics of the PYP from Halorhodospira halophila via a combined experimental and computational approach. The fluorescence quantum yield, steady-state fluorescence emission maximum, and cryotrapping spectra are demonstrated to depend on excitation wavelength. We also compare the femtosecond photodynamics …
Chemical composition and biological activities of Artemisia judaica essential oil from southern desert of Jordan
2016
Abstract Ethnopharmacologic relevance Artemisia judaica L. (Arabic name: Beithran ), is a medicinal and aromatic plant growing in the valley bottoms of desert areas, particularly in the southern desert of Jordan nearest to the Jordan-Saudi Arabia borders and in Wadi Araba in the Southern Badia. In Jordan, A. judaica is widely used in traditional medicine being recommended by aboriginal Bedouins in the North Badia region of Jordan as calmative. Furthermore, it is used for the treatment of stomach ache, heart diseases, sexual weakness, diabetes, gastro-intestinal disorders and external wounding. Additionally, other folk medicines of the Arabic region commonly use this aromatic plant for the t…
In vitro induction of cecropin genes — an immune response in a Drosophila blood cell line
1992
The Drosophila melanogaster cell line mbn-2 was explored as a model system to study insect immune responses in vitro. This cell line is of blood cell origin, derived from larval hemocytes of the mutant lethal (2) malignant blood neoplasm (1(2)mbn). The mbn-2 cells respond to microbial substances by the activation of cecropin genes, coding for bactericidal peptides. The response is stronger than that previously described for SL2 cells, and four other tested Drosophila cell lines were totally unresponsive. Bacterial lipopolysaccharide, algal laminarin (a beta-1,3-glucan), and bacterial flagellin were strong inducers, bacterial peptidoglycan fragments gave a weaker response, whereas a formyl-m…
Vibrio vulnificus biotype 2 serovar E gne but not galE is essential for lipopolysaccharide biosynthesis and virulence
2008
ABSTRACT This work aimed to establish the role of gne (encoding UDP-GalNAc 4-epimerase activity) and galE (encoding UDP-Gal-4-epimerase activity) in the biosynthesis of surface polysaccharides, as well as in the virulence for eels and humans of the zoonotic serovar of Vibrio vulnificus biotype 2, serovar E. DNA sequence data revealed that gne and galE are quite homologous within this species (≥90% homology). Mutation in gne of strain CECT4999 increased the surface hydrophobicity, produced deep alterations in the outer membrane architecture, and resulted in noticeable increases in the sensitivity to microcidal peptides (MP), to eel and human sera, and to phagocytosis/opsonophagocytosis. Furt…
Differential uptake and killing potential of Campylobacter jejuni by human peripheral monocytes/macrophages
1997
The ability of Campylobacter jejuni to survive in monocytes after phagocytic uptake was tested in a new in vitro model using adherent macrophages derived from human peripheral monocytes. The cells were stimulated with cytokines before use to ensure full phagocytic and killing activity. The kinetics of uptake and killing of bacteria was followed for 72 h with 16 strains, including stool and blood isolates and laboratory adapted strains. Significant bacterial strain differences were not observed, but the viability of phagocytosed bacteria was dependent on the individual donating the macrophages. The majority of blood donors carried macrophages that killed phagocytosed Campylobacter within 24 …
Characterisation of the essential oil of Nepeta glomerata Montbret et Aucher ex Bentham from Lebanon and its biological activities.
2011
The essential oil of Nepeta glomerata from Lebanon was studied by means of GC and GC/MS analysis; 70 compounds were identified. The oil was constituted mainly by monoterpenes and the most abundant components were α-pinene, spathulenol and carvacrol. Nepeta glomerata oil showed antibacterial activity, particularly towards Gram-positive bacteria, and also inhibited LPS-induced NO production in macrophage cell line RAW 264.7, with an IC(50) value of 78.1 µg mL(-1). Furthermore, an in vitro cytotoxic assay showed that the oil was more active on a renal adenocarcinoma cell line (48% of inhibition of proliferation at 100 µg mL(-1)) in comparison to an amelanotic melanoma.