Search results for "bacteri"
showing 10 items of 5466 documents
Antimicrobial activity of essential oil ofArtemisia judaicaL. from Algeria against multi-drug resistant bacteria from clinical origin
2015
Artemisia judaica L. essential oil was studied for antibacterial activity against various clinical isolates of bacteria resistant to a number of antibiotics. The antibacterial activity was evaluated against 20 multidrug resistant (MDR) of clinical origin compared to standard ATCC strains. The strains that showed resistance against the maximum number of antibiotics tested were selected for an antibacterial assay by three methods: Disc diffusion method, microatmosphere and dilution method. The obtained results demonstrated that the A. judaica essential oil possessed an excellent inhibitory effect against all of the tested strains. The most potent results were obtained against MRSA (Methicilli…
Evaluation of Zataria multiflora Boiss. essential oil activity against Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes by pr…
2013
Essential oils (EOs) have long been applied as flavoring agents in foods, and due to their content in antimicrobial compounds, they have potential as natural agents for food preservation. Recently, real-time PCR in combination with PMA has successfully been applied to discriminate between live Escherichia coli O157:H7 and dead bacteria killed by cumin, clove, oregano and cinnamon EOs. In this study, initial experiments were performed in order to elucidate the minimum bactericidal concentration of Zataria multiflora EOs on E. coli O157:H7, Salmonella enterica and Listeria monocytogenes. Thereafter PMA-qPCR was applied in order to selectively quantify life cells within a bacterial population …
Evaluation of the antibacterial activity of a new ozonized olive oil against oral and periodontal pathogens.
2018
Background In the present study, the antimicrobial properties of a new ozonized olive oil (O-zone gel) against oral and periodontal pathogens will be evaluated and compared with that of common CHX-based agents. Material and methods O-zone gel was compared with two agents based on chlorhexidine digluconate (CHX): Corsodyl Dental Gel and Plak Gel. A. actinomycetemcomitans, P. intermedia and S. mutans, were selected and the antibacterial capability of the compounds was tested by using direct contact agar diffusion test (DCT) and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) evaluations. Differences between specific means were analyzed by a one-way analysis…
Resistance of Immobilized Lactic Acid Bacteria to the Inhibitory Effect of Quaternary Ammonium Sanitizers
2001
Abstract The inhibitory effect of quaternary ammonium sanitizers (QAS) on the fermentation activity of lactic acid bacteria was investigated. Benzalkonium chloride and didecyl dimethyl ammonium chloride show the same inhibitory effect. In MRS agar medium and MRS liquid medium their minimum inhibitory concentration was below 2 μg/mL. Interfering molecules in milk increased this concentration of inhibitory QAS above 8 μg/mL. Both growth and acidification were decreased but by immobilizing cells in calcium alginate gel beads this inhibitory effect could be reduced. The longer the beads were used for successive acidification and were colonized by lactic acid bacteria, the better was the acidifi…
Permeabilization of the Outer Mitochondrial Membrane by Bcl-2 Proteins
2010
The proteins of the Bcl-2 family regulate the release of the apoptotic factors from mitochondria during apoptosis, a key event in physiological cell death. Although their molecular mechanisms remain unclear, the Bcl-2 proteins have been proposed to directly control the permeability of the outer mitochondrial membrane by pore formation. Indeed, they share structural features with the pore forming domains of some bacterial toxins and they can give rise to proteolipidic pores in model membranes. The complex level of regulation needed to decide the fate of the cell is achieved by an intricate interaction network between different members of the family. Current models consider multiple parallel …
Verifying a medical protocol with temporal graphs: the case of a nosocomial disease.
2014
Abstract Objective Our contribution focuses on the implementation of a formal verification approach for medical protocols with graphical temporal reasoning paths to facilitate the understanding of verification steps. Materials and methods Formal medical guideline specifications and background knowledge are represented through conceptual graphs, and reasoning is based on graph homomorphism. These materials explain the underlying principles or rationale that guide the functioning of verifications. Results An illustration of this proposal is made using a medical protocol defining guidelines for the monitoring and prevention of nosocomial infections. Such infections, which are acquired in the h…
Preventing root caries development under oral biofilm challenge in an artificial mouth
2013
Objectives: To study the preventive effects of chlorhexidine against root caries under oral biofilm in an artificial mouth. Study Design: Sixteen human tooth-root disks were inoculated with a salivary sample that was produced by mixing the unstimulated saliva of three adults who had no untreated caries. The disks were incubated in an artificial mouth fed with a 5% sucrose solution three times daily for one week. Eight disks received a twice daily rinse of 0.12% chlorhexidine (test group). The other eight disks were rinsed in distilled water (control). The biofilm was then studied with three techniques: colony forming unit (CFU) counting, scanning electron microscopy (SEM) and confocal laser…
Isolation and Characterization of Two Klebsiella pneumoniae Phages Encoding Divergent Depolymerases
2020
The emergence of multidrug-resistant bacteria is a major global health concern. The search for new therapies has brought bacteriophages into the spotlight, and new phages are being described as possible therapeutic agents. Among the bacteria that are most extensively resistant to current antibiotics is Klebsiella pneumoniae, whose hypervariable extracellular capsule makes treatment particularly difficult. Here, we describe two new K. pneumoniae phages, &pi
UV‐Vis Spectroscopy Reveals a Correlation Between Y263 and BV Protonation States in Bacteriophytochromes
2019
Red-light photosensory proteins, phytochromes, link light activation to biological functions by interconverting between two conformational states. For this, they undergo large-scale secondary and tertiary changes which follow small-scale Z to E bond photoisomerization of the covalently bound bilin chromophore. The complex network of amino acid interactions in the chromophore-binding pocket plays a central role in this process. Highly conserved Y263 and H290 have been found to be important for the photoconversion yield, while H260 has been identified as important for bilin protonation and proton transfer steps. Here, we focus on the roles these amino acids are playing in preserving the chemi…
Molecular architecture and activation of the insecticidal protein Vip3Aa from Bacillus thuringiensis
2020
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