Search results for "biofilm."

Agr system of Listeria monocytogenes EGD-e: role in adherence and differential expression pattern.

2007

ABSTRACT In this study, we investigated the agrBDCA operon in the pathogenic bacterium Listeria monocytogenes EGD-e. In-frame deletion of agrA and agrD resulted in an altered adherence and biofilm formation on abiotic surfaces, suggesting the involvement of the agr system of L. monocytogenes during the early stages of biofilm formation. Real-time PCR experiments indicated that the transcript levels of agrBDCA depended on the stage of biofilm development, since the levels were lower after the initial attachment period than during biofilm growth, whereas transcription during planktonic growth was not growth phase dependent. The mRNA quantification data also suggested that the agr system was a…

Rezistences pret antibakteriālajiem līdzekļiem un bioplēvju veidošanās noteikšana no ķirurģiskā materiālā izolētiem Staphylococcus epidermidis celmiem

2021

Staphylococcus epidermidis ir komensāls oportūnists, kas ir plaši sastopams kā daļa no ādas normālās mikrofloras. Bieži tas kā kontaminants nokļūst uz protēžu vai katetru virsmas un veicina noturīgu infekciju attīstību. Pateicoties S. epidermids biofilmu veidojošai īpašībai 80% grūti ārstējamu infekciju gadījumos novērojama to klātbūtne. Meticilīna rezistence ir plaši izplatīta pateicoties mecA gēna klātbūtnei. Svarīgi izprast rezistences mehānismus un biofilmu dabu, lai tās varētu laboratoriski noteikt un atrastu veidu, kā cīnīties ar sarežģītām infekcijām. Darba ietvaros noteikts, ka klīniskajos izolātos novērojama izteikta rezistence pret ciprofloksacīnu, klindamicīnu, eritromicīnu, cefo…

The immune mediators in echinoderms as souce of novel AMPs against microbial biofilms

2012

Toward potent antibiofilm degradable medical devices: A generic method for the antibacterial surface modification of polylactide

2013

International audience; The effects of biomaterials on their environment must be carefully modulated in most biomedical applications. Among other approaches, this modulation can be obtained through the modification of the biomaterial surface. This paper proposes a simple and versatile strategy to produce non-leaching antibacterial polylactide (PLA) surfaces without any degradation of the polyester chains. The method is based on a one-pot procedure that provides a "clickable" PLA surface via anionic activation which is then functionalized with an antibacterial quaternized poly(2-(dimethylamino)ethyl methacrylate) (QPDMAEMA) by covalent immobilization on the surface. The anti-adherence and an…

Nanozymes in Nanofibrous Mats with Haloperoxidase-like Activity To Combat Biofouling.

2018

Electrospun polymer mats are widely used in tissue engineering, wearable electronics, and water purification. However, in many environments, the polymer nanofibers prepared by electrospinning suffer from biofouling during long-term usage, resulting in persistent infections and device damage. Herein, we describe the fabrication of polymer mats with CeO2–x nanorods that can prevent biofouling in an aqueous environment. The embedded CeO2–x nanorods are functional mimics of natural haloperoxidases that catalyze the oxidative bromination of Br– and H2O2 to HOBr. The generated HOBr, a natural signaling molecule, disrupted the bacterial quorum sensing, a critical step in biofilm formation. The pol…

Incorporation of nisin in poly (ethylene-co-vinyl acetate) films by melt processing: a study on the antimicrobial properties

2011

Both industry and academia have shown a growing interest in materials with antimicrobial properties suitable for food packaging applications. In this study, we prepared and characterized thin films of ethylene-co-vinyl acetate (EVA) copolymer with antimicrobial properties. The films were prepared with a film blowing process by incorporating a nisin preparation as an antimicrobial agent in the melt. Two grades of EVA containing 14 and 28% (wt/wt) vinyl acetate (EVA 14 and EVA 28, respectively) and two commercial formulations of nisin with different nominal activities were used. The effect of the nisin concentration also was evaluated. The films with the highest antimicrobial activity were th…

Submicrometer-Sized Roughness Suppresses Bacteria Adhesion.

2020

Biofilm formation is most commonly combatted with antibiotics or biocides. However, proven toxicity and increasing resistance of bacteria increase the need for alternative strategies to prevent adhesion of bacteria to surfaces. Chemical modification of the surfaces by tethering of functional polymer brushes or films provides a route toward antifouling coatings. Furthermore, nanorough or superhydrophobic surfaces can delay biofilm formation. Here we show that submicrometer-sized roughness can outweigh surface chemistry by testing the adhesion of E. coli to surfaces of different topography and wettability over long exposure times (>7 days). Gram-negative and positive bacterial strains are tes…

Candida albicans biofilms on different materials for manufacturing implant abutments and prostheses

2019

[EN] Background: Morphological, physical and chemical properties of both implants and prostheses can determine the biofilm formation on their surface and increase the risk of biological complications. The aim of this study was to evaluate the capacity of biofilm formation of Candida albicans on different materials used to manufacture abutments and prostheses. Material and Methods: Biofilm formation was analyzed on cp grade II titanium, cobalt-chromium alloy and zirconia, silicone, acrylic resin (polymethylmethacrylate) and nano-hybrid composite. Some samples were partially covered with lithium disilicate glass ceramic to study specifically the junction areas. C. albicans was incubated in a …

Development and viability of biofilms grown on experimental abutments mimicking dental implants: an in vivo model

2019

Background To determine whether an experimental abutment mimicking the macro- and microstructure of a dental implant is a suitable method for recovering biofilm, and to describe the features of biofilms formed around such abutments on healthy implants. Material and Methods Experimental abutments were used in 15 patients without peri-implant diseases. After 14 days’ absence of dental hygiene in this area, the abutments were retrieved and analyzed through confocal laser scanning microscopy and scanning electron microscopy. The biofilm formation on the surface of the first 5 abutments was determined by a fluorescence-staining method using SYTO9 nucleic acid stain. In order to study the biofilm…

2017

Joint replacement surgery is associated with significant morbidity and mortality following infection with either methicillin-resistant Staphylococcus aureus (MRSA) or Staphylococcus epidermidis. These organisms have strong biofilm-forming capability in deep wounds and on prosthetic surfaces, with 103 -104 microbes resulting in clinically significant infections. To inhibit biofilm formation, we developed 3D titanium structures using selective laser melting and then coated them with a silver nanolayer using atomic layer deposition. On bare titanium scaffolds, S. epidermidis growth was slow but on silver-coated implants there were significant further reductions in both bacterial recovery (p < …