Search results for "bacteri"
showing 10 items of 5466 documents
Pyrrolomycins as potential anti-staphylococcal biofilms agents
2010
With the goal of discovering new anti-infective agents active against microbial biofilms, this investigation focused on some natural pyrrolomycins, a family of halogenated pyrrole antibiotics. In this study the anti-staphylococcal biofilm activity of pyrrolomycins C, D, F1, F2a, F2b, F3 and of the synthesized related compounds I, II, III were investigated. The susceptibility of six staphylococcal biofilms was determined by methyltiazotetrazolium staining. Most of the compounds were active at concentrations of 1.5 microg ml(-1) with significant inhibition percentages. A few of the compounds were active at the lowest screening concentration of 0.045 microg ml(-1). The population log reduction…
An MHC class II-expressing T cell clone presenting conventional antigen lacks the ability to present bacterial superantigen.
1995
We have analyzed the response of rat T cells to myelin basic protein (MBP) and the bacterial superantigen, staphylococcal enterotoxin E (SEE). Rat T cells reactive with MBP can respond to SEE presented by spleen cells but not to SEE presented by LOA, a rat T cell clone that expresses both I-A and I-E MHC class II molecules, even though LOA is much more efficient than splenic APC in the presentation of MBP. The inability of LOA to present superantigen is not due to a structural difference in MHC II molecules between LOA and the splenic APC or to differential expression of major accessory/adhesion molecules, including CD2, CD5, CD4 and CD44, on LOA. The non-responsiveness of SEE/LOA-induced T…
In vitro anti-biofilm activity of Boswellia spp. oleogum resin essential oils
2009
Aims: To evaluate the anti-biofilm activity of the commercially available essential oils from two Boswellia species. Methods and Results: The susceptibility of staphylococcal and Candida albicans biofilms was determined by methyltiazotetrazolium (MTT) staining. At concentrations ranging from 217·3 μg ml−1 (25% v/v) to 6·8 μg ml−1 (0·75% v/v), the essential oil of Boswellia papyrifera showed considerable activity against both Staphylococcus epidermidis DSM 3269 and Staphylococcus aureus ATCC 29213 biofilms. The anti-microbial efficacy of this oil against S. epidermidis RP62A biofilms was also tested using live/dead staining in combination with fluorescence microscopy, and we observed that …
Selective killing of human monocytes and cytokine release provoked by sphingomyelinase (beta-toxin) of Staphylococcus aureus.
1996
The best-known activity of Staphylococcus aureus sphingomyelinase C, alias beta-toxin, is as a hemolysin that provokes hot-cold lysis of erythrocytes which contain substantial amounts of sphingomyelin in the plasma membrane. Sheep erythrocytes are most susceptible, and we found that one hemolytic unit, representing the toxin concentration that elicits 50% hemolysis of 2.5 X 10(8) erythrocytes per ml, corresponds to 0.05 enzyme units or to approximately 0.25 microg of sphingomyelinase per ml. The cytotoxic action of beta-toxin on nucleated cells has not been described in any detail before, and the present investigation was undertaken to fill this information gap. We now identify beta-toxin a…
Discovery of 2-aryl and 2-pyridinylbenzothiazoles endowed with antimicrobial and aryl hydrocarbon receptor agonistic activities
2020
Highlights • Sixteen functionalized benzothiazoles were evaluated as antimicrobial agents and as AhR modulators. • The benzothiazoles showed noticeable antimicrobial effects against Gram-positive and Gram-negative pathogens and against the yeast C. albicans. • Six benzothiazoles exhibited significant AhR agonist effects in a cell-based reporter gene assay. • Structure-activity relationship analysis exposed some relevant headings on the substituent's contributions to the studied biological effects. • Compound 12 displayed promising biocide activity and AhR agonism as well as an adequate ADMET profile and binding similarities with FICZ.
A subunit of eukaryotic translation initiation factor 2α-phosphatase (CreP/PPP1R15B) regulates membrane traffic.
2012
The constitutive reverter of eIF2α phosphorylation (CReP)/PPP1r15B targets the catalytic subunit of protein phosphatase 1 (PP1c) to phosphorylated eIF2α (p-eIF2α) to promote its dephosphorylation and translation initiation. Here, we report a novel role and mode of action of CReP. We found that CReP regulates uptake of the pore-forming Staphylococcus aureus α-toxin by epithelial cells. This function was independent of PP1c and translation, although p-eIF2α was involved. The latter accumulated at sites of toxin attack and appeared conjointly with α-toxin in early endosomes. CReP localized to membranes, interacted with phosphomimetic eIF2α, and, upon overexpression, induced and decorated a pop…
Elpceļu infekciju gadījumos izdalīto Staphylococcus aureus jutība pret antibakteriālajiem līdzekļiem
2017
S.aureus ir gram + pozitīva baktērija, kas ir lokalizējusies degunā elpošanas traktā un uz ādas un ne vienmer ir patogēns mikroorganisms. Spēj ģēnētiski izmainīt savu šūnapvalka olbaltumvielas, padarot tos rezistentus pret antibiotikām. Meticilīn-rezistentais S. aureus (MRSA) satur mecA gēnu, kas nodrošina mikroorganismam rezistenci ne tikai pret meticilīnu un b - laktāma grupas antibiotikām, bet arī pret cefalosporīniem un citām grupām. Rezistences attīstība patogēniem ir saistīta ar plašu un bieži nepamatotu antibiotiku lietošanu terapijā. Darba mērķis: Noteikt S. aureus jutību pret antibakteriālajiem līdzekļiem, celmiem, kas izdalīti no elpceļu materiāla. Darba uzdevumi: Veikt laboratori…
Photoactivated chlorophyllin-based gelatin films and coatings to prevent microbial contamination of food products
2008
[EN] The aim of this work was to develop antimicrobial photosensitizer-containing edible films and coatings based on gelatin as the polymer matrix. incorporating sodium magnesium chlorophyllin (E-140) and sodium copper chlorophyllin (E-141). Chlorophyllins were incorporated into the gelatin film-forming solution and the inhibiting effect of the cast films was tested against Staphylococcus aureus and Listeria monocytogenes. The results demonstrated that water soluble sodium magnesium chlorophyllin and water soluble sodium copper chlorophyllin reduced the growth of S. aureus and L monocytogenes by 5 log and 4 log respectively. Subsequently, the activity of self-standing films and coatings con…
A POLYCARBOXYLIC/AMINO FUNCTIONALIZED HYALURONIC ACID DERIVATIVE FOR THE PRODUCTION OF pH SENSIBLE HYDROGELS IN THE PREVENTION OF BACTERIAL ADHESION …
2014
A graft copolymer derivative of hyaluronic acid bearing pendant amino and short polymethacrylate portions (HA-EDA-BMP-MANa) has been employed for the production of a pH sensible vancomycin releasing hydrogel and studied in vitro to test its potential anti adhesive property against Staphylococcus aureus colonization. The copolymer obtained through atom transfer radical polymerization bears chargeable (carboxyl and amino groups) portions and it could be formulated as a hydrogel at a concentration of 10% w/v. The HA-EDA-BMP-MANa hydrogels, produced at three different pH values (5, 6 and 7, respectively), were formulated with or without the addition of vancomycin (2% w/v). The vancomycin releas…
In vitro antibacterial and biofilm inhibitory activity of the sawdust essential oil of Tetraclinis articulata (vahl) against catheter-associated Stap…
2021
Abstract The aim of the present study was to determine the chemical composition, antibacterial and antibiofilm activities of the essential oil of sawdust from root burl wood of T. articulata. Nine strains including 8 clinical isolates from catheters-related infections and one ATCC 25923 were tested. Twenty-seven different compounds were identified by GC–MS in the essential oil of T. articulata extracted by hydrodistillation. Carvacrol and cedrol were the principal compounds representing 34.37 ± 0.07 and 11.07 ± 0.09 respectively. The EO had a strong antibacterial activity against all strains including one Multidrug-Resistant (MDR) and two Methicillin-Resistant S. aureus strains. Inhibition …