Search results for "Staphylococcus"
showing 10 items of 371 documents
Relationships between Staphylococcus aureus genetic background, virulence factors, agr groups (alleles), and human disease
2002
ABSTRACT The expression of most Staphylococcus aureus virulence factors is controlled by the agr locus, which encodes a two-component signaling pathway whose activating ligand is an agr -encoded autoinducing peptide (AIP). A polymorphism in the amino acid sequence of the AIP and of its corresponding receptor divides S. aureus strains into four major groups. Within a given group, each strain produces a peptide that can activate the agr response in the other member strains, whereas the AIPs belonging to different groups are usually mutually inhibitory. We investigated a possible relationship between agr groups and human S. aureus disease by studying 198 S. aureus strains isolated from 14 asym…
Impact de la modulation de la réponse inflammatoire pulmonaire et systémique de l'hôte mediée par Toll-Like Receptor 2 dans un modèle animal de pneum…
2012
EA MERS Hors CT hors EJ; Master
Jaunu Staphylococcus Epidermidis sortāzes A inhibitoru atlase izmantojot FRET skrīninga sistēmu
2020
Pētījuma mērķis ir atrast jaunus zāļu kandidātus, kuri spēj inhibēt Staphylococcus epidermidis sortāzi A, vienlaicīgi mazinot patogēnu multirezistēnces izplatīšanos. Šim mērķim tika izveidoti ģenētiski DNS konstrukti, kuri kodē S.epidermidis sortāzes A katalītisko domēnu, iebūvējot pET22b un pET28a vektoros srtA gēnu. Rekombinantā sortāzes proteīna sintēze tika inducēta ar IPTG, izmantojot BL21(DE3) celmu Escherichia coli ekspresijas sistēmā. Proteīns bez papildus heksahistidīna sekvences (pET22b vektors) tika attīrīts ar anjonapmaiņas hromatogrāfijas kolonnām, savukārt heksahistidīna sekvenci saturošā sortāze (pET28a vektors) tika attīrīta iz…
Biofilmu veidojošo Staphylococcus epidermidis antibakteriālās rezistences un mecA gēna noteikšana
2017
Staphylococcus epidermidis baktērijas mūsdienās ir kļuvušas par visbiežāk izolētajiem un būtiskākajiem koagulāzes negatīvo stafilokoku pārstāvjiem nozokomiālajā vidē, jo, būdami dominējošie oportūnistiskie patogēni, tās izraisa ievērojamu skaitu ar medicīniskajām ierīcēm saistītu infekcijas slimību cilvēkiem ar novājinātu imūnsistēmu, kļūstot par nopietnu draudu sabiedrības veselībai. S. epidermidis patogenitāte izpaužas šo baktēriju spējā producēt biofilmas, kuras kalpo kā daudzfunkcionāls virulences un antibakteriālās rezistences faktors un padara šo patogēnu izraisītās slimības ļoti grūti ārstējamas, jo tiek atvieglota antibiotiku rezistences gēnu, tai skaitā SCCmec lokalizētā mecA gēna,…
Stafilococchi: causa di mastite
2011
Staphylococcus aureus è un batterio che può provocare mastite. Negli ultimi anni sono stati isolati Stafilococchi resistenti a molti degli antibiotici usati in terapia. Il presente lavoro ha lo scopo di caratterizzare gli Stafilococchi circolanti in Sicilia per prevenire la diffusione di batteri patogeni resistenti
PVC silver zeolite composites with antimicrobial properties
2011
Poly(vinyl chloride) (PVC) composites containing increasing amounts (2-20%, w/w) of silver zeolite (SZ) were prepared by melt mixing and characterized by thermal, mechanical and rheological analyses. The addition of large amount of SZ did not influence the processability and the formability of the composites, if compared to neat plasticized PVC. The antibacterial activity of PVC SZ composites was tested on Escherichia coli and Staphylococcus epidermidis and resulted promising both in culture broth and on agar plate and also in sterile urine seeded with these strains, for simulation purposes. In sterile urine, composites induced a significant reduction (4-6 log units) of viability of both st…
Ceļa locītavas septiska artrīta ārstēšanas rezultāti
2015
Pasaulē nav vienotas taktikas ceļa locītavas septiska artrīta ārstēšanai. Ir vairāki protokoli, kuros pie septiska artrīta izvēlas punktēt ceļa locītavu, tādējādi nodrošinot drenāžu. Cits protokols paredz artroskopisku skalošanu vairākas reizes, neuzrādot konkrētu skaitu. Ja augstāk minētās darbības kopā ar antibakteriālu terapiju nedod vēlamo efektu, dažkārt tiek veikta vaļēja sinovektomija vai pat locītavas endoprotezēšana. Traumatoloģijas un ortopēdijas slimnīcā nav vienota protokola ceļa locītavas septiska artrīta ārstēšanai. Parasti cenšas 3 reizes izskalot ceļa locītavu ar troakāriem, izmantojot 6 litrus fizioloģiskā šķidruma. Tad tiek izvērtēti iekaisuma rādītāji dinamikā un lemts pa…
Inhibition of bacterial virulence factors of foodborne pathogens by paprika (Capsicum annuum L.) extracts
2022
Abstract Capsicum annuum extracts of different polarities were tested for their antimicrobial, antibiofilm, and anti-Quorum sensing (QS) activity against several pathogenic microorganisms and possible toxic effects using an in vivo model (Galleria mellonella L.). Hexane (HE) and Chloroform extract (CE) were the most active in inhibiting biofilm formation of the eight bacteria tested, with inhibition percentages between 22 and 88% for a concentration of 100 μg/mL. These extracts were potent inhibitors of Staphylococcus aureus biofilm, and microscopy analysis confirmed a significant reduction in adhered cells. Moreover, polystyrene surfaces coated with these extracts decreased Staph. aureus a…
ChemInform Abstract: One-Step Synthesis, Crystallographic Studies and Antimicrobial Activity of New 4-Diazopyrazole Derivatives.
2010
Summary A number of new 4-diazopyrazole derivatives were prepared by the reaction of 1- R -3-methyl-5(R 1 -substituted)benzamidopyrazoles with a sevenfold excess of nitrous acid in acetic medium. The compounds were tested for activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus faecalis, Listeria monocytogenes, Candida albicans, Candida tropicalis and Paecilomyces varioti . The highest microbial susceptibility was shown by Gram-positive bacteria, with minimum inhibitory concentrations (MIC) in the range 0.5–12.5 μg/mL. For S aureus the R 1 substituents were screened utilizing the Topliss operational scheme. The 4-nitro g…
Staphylococcus aureus alpha-toxin attack on human platelets promotes assembly of the prothrombinase complex.
1990
alpha-Toxin, the major cytolysin of Staphylococcus aureus, promotes blood coagulation by its attack on human platelets (Bhakdi S., Muhly, M., Mannhardt, U., Hugo, F., Klapettek, K., Mueller-Eckhardt, C., and Roka, L. (1988) J. Exp. Med. 168, 527-542). In the present study we demonstrate that toxin attack on gel-filtered human platelets initiates the assembly of prothrombinase complexes at rates up to 10-fold of controls. Treatment of platelets with 0.1 microgram/ml alpha-toxin resulted in generation of 1.4 units of thrombin/10(8) platelets. A similar rate of thrombin generation was noted when platelets were subjected to three cycles of freezing and thawing. However, the alpha-toxin-induced …