Search results for "biofilm."
showing 10 items of 382 documents
Solid lipid nanoparticles containing vancomycin: preparation, characterization and in vitro anti-Staphylococcus aureus biofilms activity
2009
Coagulase-negative staphylococci and Staphylococcus aureus are the most common cause of nosocomial infections and can induce a wide spectrum of diseases associated with remarkable morbidity and mortality. Biofilms of staphylococci are intrinsically resistant to conventional antibiotics and, being commonly associated with implanted medical device, such as catheters and vascular grafts, have the potential to cause blood-stream infections. The paper describes the preparation and characterization of vancomycin-loaded Solid Lipid Nanoparticles (SLNs) and in vitro studies of the inhibition of Staphylococcus aureus ATCC 29213 biofilms in the presence of this nanoparticle system. Methods. The vanco…
Pyrrolomycins as antimicrobial agents. Microwave-assisted organic synthesis and insights into their antimicrobial mechanism of action
2019
Abstract New compounds able to counteract staphylococcal biofilm formation are needed. In this study we investigate the mechanism of action of pyrrolomycins, whose potential as antimicrobial agents has been demonstrated. We performed a new efficient and easy method to use microwave organic synthesis suitable for obtaining pyrrolomycins in good yields and in suitable amount for their in vitro in-depth investigation. We evaluate the inhibitory activity towards Sortase A (SrtA), a transpeptidase responsible for covalent anchoring in Gram-positive peptidoglycan of many surface proteins involved in adhesion and in biofilm formation. All compounds show a good inhibitory activity toward SrtA, havi…
Origanum vulgare subsp. hirtum Essential Oil Prevented Biofilm formation and showed antibacterial activity against planktonic and sessile bacterial c…
2013
Essential oils from six different populations of Origanum vulgare subsp. hirtum were compared for their antibiofilm properties. The six essential oils (A to F) were characterized by a combination of gas chromatography with flame ionization detector and gas chromatography with mass spectrometer detector analyses. All oils showed weak activity against the planktonic form of a group of Staphylococcus aureus strains and against a Pseudomonas aeruginosa ATCC 15442 reference strain. The ability to inhibit biofilm formation was investigated at sub-MIC levels of 200, 100, and 50 m g/ml by staining sessile cells with safranin. Sample E showed the highest average effectiveness against all tested stra…
Photothermal nanofibrillar membrane based on hyaluronic acid and graphene oxide to treat Staphylococcus aureus and Pseudomonas aeruginosa infected wo…
2022
Here we reported the fabrication of an electrospun membrane based on a hyaluronic acid derivative (HA-EDA) to be used as a bandage for the potential treatment of chronic wounds. The membrane, loaded with graphene oxide (GO) and ciprofloxacin, showed photothermal properties and light-triggered drug release when irradiated with a near-infrared (NIR) laser beam. Free amino groups of HA-EDA derivative allowed autocrosslinking of the elec- trospun membrane; thus, a substantial enhancement in the hydrolytic resistance of the patch was obtained. In vitro antibacterial activity studies performed on Staphylococcus aureus and Pseudomonas aeruginosa revealed that such electrospun membranes, due to the…
Differences in metabolic profiles of planktonic and biofilm cells in Staphylococcus aureus - (1)H Nuclear Magnetic Resonance search for candidate bio…
2013
Staphylococcus aureus is responsible for many types of infections related to biofilm presence. As the early diagnostics remains the best option for prevention of biofilm infections, the aim of the work presented was to search for differences in metabolite patterns of S. aureus ATCC6538 biofilm vs. free-swimming S. aureus planktonic forms. For this purpose, Nuclear Magnetic Resonance (NMR) spectroscopy was applied. Data obtained were supported by means of Scanning Electron Microscopy, quantitative cultures and X-ray computed microtomography. Metabolic trends accompanying S. aureus biofilm formation were found using Principal Component Analysis (PCA). Levels of isoleucine, alanine and 2,3-but…
Branched High Molecular Weight Glycopolypeptide With Broad-Spectrum Antimicrobial Activity for the Treatment of Biofilm Related Infections.
2017
There are few therapeutic options to simultaneously tackle Staphylococcus aureus and Pseudomonas aeruginosa, two of the most relevant nosocomial and antibiotic-resistant pathogens responsible for implant, catheters and wound severe infections. The design and synthesis of polymers with inherent antimicrobial activity have gained increasing attention as a safe strategy to treat multi-drug-resistant microbes. Here, we tested the activity of a new polymeric derivative with glycopolypeptide architecture (PAA-VC) bearing l-arginine, vancomycin, and colistin as side chains acting against multiple targets, which give rise to a broad spectrum antimicrobial activity favorably combining specific and n…
ANTIMICROBIAL AND ANTISTAPHYLOCOCCAL BIOFILM ACTIVITY FROM THE SEA URCHIN PARACENTROTUS LIVIDUS
2009
Aims: Staphylococcal biofilm-associated infections are resistant to conventional antibiotics. Consequently, new agents are needed to treat them. With this aim, we focused on the effector cells (coelomocytes) of the sea urchin Paracentrotus lividus immune system. Methods and Results: We tested the activity of the 5-kDa peptide fraction of the cytosol from coelomocytes (5-CC) against a group of Gram-positive, Gram-negative bacteria and fungi. We determined minimal inhibitory concentrations (MICs) ranging from 253.7 to 15.8 mg ml(-1). We observed an inhibitory activity and antibiofilm properties of 5-CC against staphylococcal biofilms of reference strains Staphylococcus epidermidis DSM 3269 an…
Effect of temperature on the release of carvacrol and cinnamaldehyde incorporated into polymeric systems to control growth and biofilms ofEscherichia…
2015
This study assessed the effect of temperature on the release of essential oil components incorporated by melt compounding into polymeric films. Specifically, polyethylene-co-vinylacetate (EVA) films containing carvacrol (CAR) and cinnamaldehyde (ALD), alone and in combination, were prepared and their surface and mechanical properties and antibacterial and anti-biofilm activity against Escherichia coli and Staphylococcus aureus were evaluated. The addition of ALD and CAR did not provoke variation in the surface morphology of EVA and allowed their delivery. At 37°C, films containing CAR, ALD or their combination (25+75%) were found to have the strongest bactericidal effect, whereas at lower t…
Phenotypic and genotypic study on antibiotic resistance and pathogenic factors of Staphylococcus aureus isolates from small ruminant mastitis milk in…
2021
Staphyloccoccus aureus is the major cause of mastitis in small ruminants in the Mediterranean farms causing severe losses to dairy industry. Antibiotic treatment has been the most common approach to control these infections. Aim of this study was to investigate antimicrobial resistance (AMR), virulence factors and biofilm-related genes of 84 Sicilian strains of S. aureus isolated from sheep and goats milk during two different periods δT1 (2006-2009) and δT2 (2013-2015). Kirby Bauer method and Polymerase Chain Reaction (PCR) were utilized to monitor AMR and related genes (mecA, tetK, tetM, ermA, ermC). Moreover, toxin genes (tsst-1, sea-see, seg-sej, and sep) and biofilm genes (bap, ica, sas…
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…