Search results for "BIOFILM"

Electron transfer mechanism in Shewanella loihica PV-4 biofilms formed at graphite electrode

2012

Abstract Electron transfer mechanisms in Shewanella loihica PV-4 viable biofilms formed at graphite electrodes were investigated in potentiostat-controlled electrochemical cells poised at oxidative potentials (0.2 V vs. Ag/AgCl). Chronoamperometry (CA) showed a repeatable biofilm growth of S. loihica PV-4 on graphite electrode. CA, cyclic voltammetry (CV) and its first derivative shows that both direct electron transfer (DET) mediated electron transfer (MET) mechanism contributes to the overall anodic (oxidation) current. The maximum anodic current density recorded on graphite was 90 μA cm − 2 . Fluorescence emission spectra shows increased concentration of quinone derivatives and riboflavi…

Effect of E. coli biofilm formation and removal on passive films on AISI 316L during fermentation processes

2021

Abstract 316L coupons were sanitized in hot water vapour inducing iron enrichment in passive films. Coupons were then immersed in a pilot fed-batch fermenter in presence of E. coli. Sanitization causes iron enrichment in passive films. Fermentation causes the growth of biofilm on the SS, constituted by bacteria embedded in an extracellular polymeric substance. During fermentation SS open circuit potential is very negative due to low oxygen concentration on its surface, while the chelating action of siderophores induces chromium enrichment in the passive film. Disinfection in NaClO for 30 min allows removal of biofilm and formation of a protective passive film.

CORROSION RESISTANCE OF DIFFERENT STAINLESS STEEL GRADES IN FOOD AND BEVERAGE INDUSTRY

2020

Curcumin derivatives as inhibitors of Gram positive and Gram negative biofilm formation

2015

Novel chemical countermeasures against staphylococcal biofilms

2010

Some natural and synthetic related pyrrolomycins, a family of halogenated pyrrole antibiotics, showed anti-biofilm properties in vitro at low concentration (0.045μg/mL) against preformed staphylococcal biofilms. Moreover, considering the human cell toxicity, the selectivity indexes (ratio of cytotoxicity to antibiofilm activity) of some of them were very interesting. The present study aims to investigate if the pyrrolomycins could also prevent staphylococcal biofilm formation. The evaluation of S.aureus ATCC 25923 biofilm formation inhibition was conducted by safranin staining method. At tested concentrations of 0.18, 0.09, 0.045 μg/mL (concentrations much lower than MIC value determined on…

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…