Search results for "(Staphylococcus)"
showing 10 items of 371 documents
Asymmetric Disulfanylbenzamides as Irreversible and Selective Inhibitors of Staphylococcus aureus Sortase A
2020
Abstract Staphylococcus aureus is one of the most frequent causes of nosocomial and community‐acquired infections, with drug‐resistant strains being responsible for tens of thousands of deaths per year. S. aureus sortase A inhibitors are designed to interfere with virulence determinants. We have identified disulfanylbenzamides as a new class of potent inhibitors against sortase A that act by covalent modification of the active‐site cysteine. A broad series of derivatives were synthesized to derive structure‐activity relationships (SAR). In vitro and in silico methods allowed the experimentally observed binding affinities and selectivities to be rationalized. The most active compounds were f…
A Silicone Ventricular Catheter Coated with a Combination of Rifampin and Trimethoprim for the Prevention of Catheter-related Infections
1998
So-called antiinfective catheters which are generated by incorporation of antimicrobial substances into polymers appear to be effectful devices in the prevention of catheter related infections. Such devices mainly act by prevention of bacterial colonization of the catheter surface rather than by inhibition of adherence. In a preceding study, we developed a rifampin-containing silicone catheter for the prevention of ventricular shunt infection. In the present study, this work was continued with a combination of antimicrobials incorporated in silicone ventricular catheters to reduce the risk of rifampin resistance and to expand the antimicrobial spectrum. We found that the drug release kineti…
Staphylococcus aureus nēsāšana veselu cilvēku starpā
2016
Staphylococcus aureus bieži vien kolonizē nāsis, padarot veselu cilvēku par šo patogēno mikroorganismu nēsātāju. Medicīnas darbiniekiem un medicīnas studentiem, kas ir pakļauti ilgu laika periodu slimnīcas videi, ir lielākais risks kļūt par S.aureus nēsātāju. Nēsātāji darbojas kā pastāvīgi infekcijas avoti. Stafilokoku infekcijas visbiežāk attīstās imūn-novājinātiem pacientiem, tāpēc nēsāšana medicīnas darbinieku vidū ir sevišķi svarīga. Darba mērķis: noteikt S.aureus nēsāšanas biežumu medicīnas fakultātes studentu vidū. Galvenie uzdevumi: 1.Noteikt S.aureus nēsāšanas atkarību no medicīnas fakultātes kursa ( otrais kurss, sestais kurss) – tātad no saskares ar slimnīcas vidi. 2.Noteikt S.aur…
Staphylococcus epidermidis un to rezistence pret antibakteriālajām vielām
2016
Staphylococcus epidermidis ir vieni no biežākajiem nozokomiālo infekciju un bakterēmijas ierosinātājiem. S.epidermidis bieži ir meticilīnrezistenti un tas nozīmē, ka baktērijas ir rezistentas pret klasiskajām β – laktāmu antibakteriālajām vielām. Meticilīnrezistenci nosaka mecA gēns , kurš ir integrēts baktērijas DNS. Baktēriju rezistence būtiski ietekmē arī infekciju terapijas izvēli. Darba mērķis ir izpētīt Staphylococcus epidermidis rezistenci pret antibakteriālajiem preparātiem no klīniskajiem materiāliem izolētajos paraugos. Pētījumā tika noskaidrots , ka S.epidermidis uzrādīja augstu rezistenci pret ampicilinu – 17 gadījumos ( 83% ), un arī pret eritromicīnu – 37 gadījumi ( 74% ). 31 …
No perifēro vēnu katetru uzsējumiem izdalīto Staphylococcus epidermidis bioplēvju veidošana un jutība pret antibakteriālajiem līdzekļiem
2015
Mūsdienās Staphylococcus epidermidis ir vieni no visbiežāk izolētajiem nozokomiālo infekciju izraisītājiem pacientu grupā ar tādiem riska faktoriem kā novājināta imūnsistēma un implantētām medicīniskajām ierīcēm. Visbūtiskākā ar svešķermeņiem saistīto infekciju patoģenēzē ir šo mikroorganismu spēja kolonizēt medicīnisko ierīču abiotiskās virsmas, formējot bioplēvi, kas sastāv no daudzslāņu šūnu klasteriem, iekļautiem ekstracelulārajā gļotu substancē un ir saistīta ar šo baktēriju rezistenci pret antibakteriālajiem līdzekļiem, padarot to izraisītās slimības grūti ārstējamas. Pētījuma mērķis: Analizēt no perifēro vēnu katetru uzsējumiem izdalīto Staphylococcus epidermidis bioplēvju veidošanas…
4-Diazopyrazole Derivatives as Potential New Antibiofilm Agents
2008
<i>Background:</i> The recognition that chronic infections and infections associated with medical devices are biofilm related has been the impulse for investigating the antibiofilm properties of some diazopyrazoles biologically active as antimicrobials. <i>Methods:</i> The susceptibility of staphylococcal biofilms was determined at concentrations ranging from 25 to 1.5 µg/ml using crystal violet and methylthiazotetrazolium (MTT) staining. In the case of <i>Candida albicans,</i> we first assessed the anti-germ tube formation effect of 4-NO<sub>2</sub> (compound 1c) and then we evaluated its antibiofilm activity at concentrations ranging from 10…
Subcytocidal attack by staphylococcal alpha-toxin activates NF-kappaB and induces interleukin-8 production.
2001
ABSTRACTFormation of transmembrane pores by staphylococcal alpha-toxin can provoke a spectrum of events depending on target cell species and toxin dose, and in certain cases, repair of the lesions has been observed. Here, we report that transcriptional processes are activated as a response of cells to low toxin doses. Exposure of monocytic (THP-1) or epithelial (ECV304) cells to 40 to 160 ng/ml alpha-toxin provoked a drop in cellular ATP level that was followed by secretion of substantial amounts of interleukin-8 (IL-8). Cells transfected with constructs comprising the proximal IL-8 promoter fused to luciferase or to green fluorescent protein cDNA exhibited enhanced reporter gene expression…
The hemagglutinin of Staphylococcus saprophyticus is a major adhesin for uroepithelial cells.
1996
The 160-kDa hemagglutinin of Staphylococcus saprophyticus also serves as a fibronectin-binding protein, and the two activities may be present on different parts of the molecule. Bacteria expressing the 160-kDa hemagglutinin bound in large numbers to histological sections of human ureters, whereas nonhemagglutinating bacteria did not bind. Binding was decreased by an antiserum to the 160-kDa protein and by a preparation of sheep erythrocyte membranes. Fibronectin had no effect. We therefore conclude that binding of S. saprophyticus to uroepithelial cells is mediated by the hemagglutinating activity of the 160-kDa surface protein.
Control of biofilm formation by poly-ethylene-co-vinyl acetate films incorporating nisin.
2010
The aim of this study was to evaluate the effect of poly-ethylene-co-vinyl acetate (EVA) films incorporating different concentrations (0.1%, 0.5% and 1%) of nisin on the biofilm-forming ability of Listeria monocytogenes ATCC 7644, Staphylococcus aureus 815 and Staphylococ-cus epidermidis ATCC 35984. Nisin was incorporated into two grades of EVA (EVA14 and EVA28) in the melt during a common film-blowing operation. The efficacy of EVA/nisin films was evaluated by biofilm biomass measurements and Live/Dead staining in combination with fluorescence microscopy. In order to evaluate whether the nisin incorporation could modify the film surface properties, contact angle measurements and scanning e…
Antibacterial Activity of Flavonoids Against Methicillin-resistant Staphylococcus aureus strains
2000
An experimental and theoretical study was performed on the anti-staphylococcal activity of 18 natural and synthetic flavonoids against methicillin-resistant Staphylococcus aureus strains. The analysed flavonoids belong to three well-differentiated structural patterns: chalcones, flavanones and flavones. The quantitative analysis of the anti-staphylococcal activity of the compounds was carried out by determining their percent inhibition degree. The hierarchical cluster analysis method was used to analyse the anti-MRSA activity of the compounds. With this methodology, the flavonoids were classified into four groups according to their anti-staphylococcal activity (high, sufficient, intermediat…