Biofilm Control | Date: 2017-03-15
The invention relates to a method for determining the enzyme activity of enzymes, and to a device for determining the enzyme activity of an enzyme for implementing said method. The invention is applicable especially in analytical fields, in fields of biological and enzymological research, in the pharmaceutical field and/or in the medical field.
PubMed | BioFilm Control, Dijon University Hospital, French Institute of Health and Medical Research and Vivexia Laboratory
Type: Journal Article | Journal: Pathogens and disease | Year: 2016
Biofilms are complex communities of microorganisms embedded in an extracellular matrix and adherent to a surface. The development was described as a four-stage process leading to the formation of a mature biofilm which was resistant to immune system and antibiotic actions. In bone and joint infections (BJIs), the formation of biofilms is a leading cause of treatment failure. Here we study the capacity of 11 antibiotics commonly used in the treatment of BJIs to inhibit the biofilm formation on 29 clinical Staphylococcus aureus isolates by a new test called Antibiofilmogram() The minimal inhibitory concentration (MIC) and biofilm MIC (bMIC) were determined in vitro and showed similar values for clindamycin, fusidic acid, linezolid and rifampin. Reversely, daptomycin, fosfomycin, gentamicin and ofloxacin showed a bMIC distribution different from MIC with bMIC above breakpoint. Finally, cloxacillin, teicoplanin and vancomycin revealed an intermediate bMIC distribution with a strain-dependent pattern. A murine in vivo model of catheter-associated S. aureus infection was made and showed a significant reduction, but not total prevention, of catheter colonization with cloxacillin at bMIC, and no or limited reduction with cloxacillin at MIC. Antibiofilmogram() could be of great interest after surgical operations on contaminated prostheses and after bacteremia in order to prevent the colonization of the device.
PubMed | BioFilm Control, Institute of Chemistry of Clermont-Ferrand and University of Auvergne
Type: Journal Article | Journal: Applied biochemistry and biotechnology | Year: 2016
The aim of this study was to investigate the possibility of immobilizing peptoid on chitosan film in order to generate new active material. Chitosan films have been grafted for the first time with short-length peptoid oligomers displaying antioxidant activities. The antioxidant activity of the selected peptoids was initially investigated with the DPPH assay and hydroxyl radical procedure. The metal chelating capacity of peptoids was also evaluated prior to their covalent attachment to chitosan. The benefit of chitosan functionalization with respect to its intrinsic antioxidant properties was finally evaluated in the present study. Interestingly, an increase of up to 90% of the antioxidant activity of chitosan was observed.
Badel S.,University Blaise Pascal |
Laroche C.,University Blaise Pascal |
Gardarin C.,University Blaise Pascal |
Petit E.,Laboratoire des Polysaccharides Microbiens et Vegetaux |
And 2 more authors.
Enzyme and Microbial Technology | Year: 2011
The activity of polysaccharide cleavage enzymes has usually been evaluated by qualitative plate screening methods and quantitative colorimetric or chromatographic assays. The recent development of protein engineering has shown the limits of these techniques when applied to high throughput screening. Here we propose a microplate method to measure the activity of polysaccharide cleavage enzymes through small variations in viscosity. Polysaccharide solutions are co-incubated with magnetic particles in enzyme buffers. The cleavage action of polymer-degrading enzymes increases the mobility of the particles in a magnetic field, even at low levels of enzyme activities. This reproducible, sensitive technique was used to evaluate enzymatic specificity towards substrates. BioFilm indices (BFI) determined by associated software were used to follow enzyme kinetics and measure the usual variables. © 2010 Elsevier Inc.
PubMed | Biofilm Control, University of Barcelona, Public University of Navarra and Radboud University Nijmegen
Type: Comparative Study | Journal: Applied and environmental microbiology | Year: 2014
Biofilm formation by nontypeable (NT) Haemophilus influenzae remains a controversial topic. Nevertheless, biofilm-like structures have been observed in the middle-ear mucosa of experimental chinchilla models of otitis media (OM). To date, there have been no studies of biofilm formation in large collections of clinical isolates. This study aimed to investigate the initial adhesion to a solid surface and biofilm formation by NT H. influenzae by comparing isolates from healthy carriers, those with noninvasive respiratory disease, and those with invasive respiratory disease. We used 352 isolates from patients with nonbacteremic community-acquired pneumonia (NB-CAP), chronic obstructive pulmonary disease (COPD), OM, and invasive disease and a group of healthy colonized children. We then determined the speed of initial adhesion to a solid surface by the BioFilm ring test and quantified biofilm formation by crystal violet staining. Isolates from different clinical sources displayed high levels of biofilm formation on a static solid support after growth for 24 h. We observed clear differences in initial attachment and biofilm formation depending on the pathology associated with NT H. influenzae isolation, with significantly increased biofilm formation for NT H. influenzae isolates collected from patients with invasive disease and OM compared with NT H. influenzae isolates from patients with NB-CAP or COPD and healthy colonized subjects. In all cases, biofilm structures were detached by proteinase K treatment, suggesting an important role for proteins in the initial adhesion and static biofilm formation measured by crystal violet staining.
Badel S.,University Blaise Pascal |
Bernardi T.,BioFilm Control |
Michaud P.,University Blaise Pascal
Biotechnology Advances | Year: 2011
Lactobacilli have the ability to produce different kinds of exopolysaccharides (EPS) exhibiting a wide diversity of structures. EPS are classified, according to their composition into homopolysaccharides and heteropolysaccharides. One of their most described applications is their utilization as texturing agents naturally synthesized in the fermented food products. Nowadays, in regard to demand of modern consumers focusing towards safe and healthy food without additives, new perspectives of development appear for these biopolymers. The GRAS (Generally Recognized As Safe) and probiotic status of some lactobacilli give to them more preference for consumable EPS production. The main drawbacks limiting their industrial expansion are their low yields of production and the validation of their healthy allegations. Moreover, the texturing role of these exopolysaccharides, notably in dairy products, is actually a controversial issue. This review focuses on the novel ways of EPS production employing Lactobacillus spp. and their potential as nutraceuticals. © 2010 Elsevier Inc.
Biofilm Control | Date: 2011-12-11
The present invention relates to a method for measuring the effect of a force on a film. In particular, the present invention relates to a method for measuring the effect of a mechanical, hydrodynamic or physical force, for example, on the integrity of a film, for example a film made of microorganisms, foodstuffs and/or chemical substances. The present invention is especially applicable to the fields of biology, chemistry, biotechnology and food processing.
Biofilm Control | Date: 2011-06-30
The present invention relates to a method for detecting molecular interactions in a solution. In particular, the present invention relates to a method for detecting interactions between two substances that are likely to interact with one another. The present invention can be used in particular in the field of scientific research and in the field of medical analysis.
Biofilm Control | Date: 2013-12-31
Diagnostic preparations other than for medical or veterinary use. diagnostic reagents for medical use. apparatus and instruments for scientific research in laboratories, namely, air analysis apparatus, chemistry apparatus and instruments for testing the presence or the efficacy of antimicrobial agents, DNA chips, chromatography apparatus for laboratory use, computer programs used for testing the presence or the efficacy of antimicrobial agents; data processing apparatus, detectors of the presence or efficacy of antimicrobial agents; diagnostic apparatus, not for medical purposes, for testing the presence or the efficacy of antimicrobial agents; diagnostic apparatus for testing the presence or the efficacy of antimicrobial agents in food; incubators for bacteria culture, interfaces for computers, instruments and machines for testing the presence or the efficacy of antimicrobial agents, measures of the presence or the efficacy of antimicrobial agents, measuring apparatus of the presence or the efficacy of antimicrobial agents, measuring instruments of the presence or the efficacy of antimicrobial agents, observation instruments meant for testing the presence or the efficacy of antimicrobial agents; apparatus and instruments for physics meant for testing the presence or the efficacy of antimicrobial agents; probes meant for scientific purposes for testing the presence or the efficacy of antimicrobial agents; computer programs downloadable software for testing the presence or the efficacy of antimicrobial agents; scanners data processing equipment; apparatus, not for medical purposes, for testing the presence or the efficacy of antimicrobial agents. blood testing apparatus, catheters meant for testing the presence or the efficacy of antimicrobial agents; diagnostic apparatus for medical purposes meant for testing the presence or the efficacy of antimicrobial agents; medical apparatus and instruments meant for testing the presence or the efficacy of antimicrobial agents; urological imaging systems for detecting the presence or the efficacy of antimicrobial agents; veterinary apparatus and instruments meant for testing the presence or the efficacy of antimicrobial agents.
PubMed | BioFilm Control, CNRS Pascal Institute, University of Picardie Jules Verne and CNRS Microorganisms Laboratory: Genome and Environment
Type: Journal Article | Journal: PloS one | Year: 2014
Competition and cooperation phenomena occur within highly interactive biofilm communities and several non-biocides molecules produced by microorganisms have been described as impairing biofilm formation. In this study, we investigated the anti-biofilm capacities of an ubiquitous and biofilm producing bacterium, Klebsiella pneumoniae. Cell-free supernatant from K. pneumoniae planktonic cultures showed anti-biofilm effects on most Gram positive bacteria tested but also encompassed some Gram negative bacilli. The anti-biofilm non-bactericidal activity was further investigated on Staphylococcus epidermidis, by determining the biofilm biomass, microscopic observations and agglutination measurement through a magnetic bead-mediated agglutination test. Cell-free extracts from K. pneumoniae biofilm (supernatant and acellular matrix) also showed an influence, although to a lesser extend. Chemical analyses indicated that the active molecule was a high molecular weight polysaccharide composed of five monosaccharides: galactose, glucose, rhamnose, glucuronic acid and glucosamine and the main following sugar linkage residues [ 2)--L-Rhap-(1 ]; [ 4)--L-Rhap-(1 ]; [-D-Galp-(1 ]; [ 2,3)--D-Galp-(1 ]; [ 3)--D-Galp-(1 ] and, [ 4)--D-GlcAp-(1 ]. Characterization of this molecule indicated that this component was more likely capsular polysaccharide (CPS) and precoating of abiotic surfaces with CPS extracts from different serotypes impaired the bacteria-surface interactions. Thus the CPS of Klebsiella would exhibit a pleiotropic activity during biofilm formation, both stimulating the initial adhesion and maturation steps as previously described, but also repelling potential competitors.