Polysaccharides against Viruses: Immunostimulatory Properties and the Delivery of Antiviral Vaccines and Drugs.

Because viruses still represent a significant threat to human and animal health worldwide, the development of effective weapons against viral infections remains a top priority for the biopharmaceutical industry. This article reviews the dietary and pharmaceutical applications of polysaccharides (PS), first of all chitosan, in the prevention and treatment of viral diseases, focusing more particularly on solid or gel micro/nanoparticulate systems. The intrinsic antiviral activity of PS and their immunostimulatory effects, implemented in animal and human diets, are first surveyed.

Polysaccharide-based chromatographic adsorbents for virus purification and viral clearance.

Viruses still pose a significant threat to human and animal health worldwide. In the fight against viral infections, high-purity viral stocks are needed for manufacture of safer vaccines. It is also a priority to ensure the viral safety of biopharmaceuticals such as blood products.

Cellulose-based virus-retentive filters: a review.

Viral filtration is a critical step in the purification of biologics and in the monitoring of microbiological water quality. Viral filters are also essential protection elements against airborne viral particles. The present review first focuses on cellulose-based filter media currently used for size-exclusion and/or adsorptive filtration of viruses from biopharmaceutical and environmental water samples.

Polysaccharide-based antibiofilm surfaces.

Unlabelled: Surface treatment by natural or modified polysaccharide polymers is a promising means to fight against implant-associated biofilm infections. The present review focuses on polysaccharide-based coatings that have been proposed over the last ten years to impede biofilm formation on material surfaces exposed to bacterial contamination. Anti-adhesive and bactericidal coatings are considered.

Biofilm-induced modifications in the proteome of Pseudomonas aeruginosa planktonic cells.

While recent studies focused on Quorum Sensing (QS) role in the cell-to-cell communication in free or biofilm cultures, no work has been devoted up to now to investigate the communication between sessile and planktonic bacteria. In this aim, we elaborated an original two-chambered bioreactor and used a proteomic approach to study the alterations induced by Pseudomonas aeruginosa biofilm cells on protein expression in planktonic counterparts (named SIPs for Surface-Influenced Planktonics). Proteomic analyses revealed the existence of 31 proteins whose amount varied in SIPs, among which five corresponded to hypothetic proteins and two (the Fur and BCP proteins) are involved in bacterial response to oxidative stress.

Membrane proteomes of Pseudomonas aeruginosa and Acinetobacter baumannii.

Acinetobacter baumannii and Pseudomonas aeruginosa are known for their intrinsic resistance to antibiotics. Between mechanisms involved in this resistance, diminished expression of outer membrane proteins and up-regulation of efflux pumps play an important role. The characterization of membrane proteins is consequently necessary because of their importance in the antibiotic resistance but also in virulence.

Identification of biofilm-associated cluster (bac) in Pseudomonas aeruginosa involved in biofilm formation and virulence.

Biofilms are prevalent in diseases caused by Pseudomonas aeruginosa, an opportunistic and nosocomial pathogen. By a proteomic approach, we previously identified a hypothetical protein of P. aeruginosa (coded by the gene pA3731) that was accumulated by biofilm cells.

Impact of rpoS deletion on the proteome of Escherichia coli grown planktonically and as biofilm.

To investigate the role of rpoS in gene expression of Escherichia coli cells grown as biofilms, we compared the proteomes of a rpoS mutant and the wild-type strain. Experiments were performed on planktonic cells (in exponential or stationary growth phase) and biofilms developed on glass wool. Spot-by-spot comparison of gels obtained from biofilm and planktonic wild-type organisms showed that the intensity of between 22 and 30% of detected spots was affected by the growth mode, depending of the control used.

Proteomic analysis of Staphylococcus aureus biofilms grown in vitro on mechanical heart valve leaflets.

The in vitro colonization of three commercial heart valve leaflets by Staphylococcus aureus was investigated. The leaflets, made of pyrolytic carbon alloyed with or without silicon, displayed similar surface properties (wettability, roughness) and were readily colonized by S. aureus that formed patchy biofilms on the three supports.

Protein expression in Escherichia coli S17-1 biofilms: impact of indole.

Bacteria undergo significant changes during adherence to surfaces and biofilm development. Cell-to-cell signalling molecules are known to be involved in these phenotypic adaptations to the sessile mode of life. We demonstrated previously that indole can act as an extracellular signal to regulate biofilm formation in E.

Long-term incomplete xylose fermentation, after glucose exhaustion, with Candida shehatae co-immobilized with Saccharomyces cerevisiae.

Saccharomyces cerevisiae and Candida shehatae were co-immobilized in an agar sheet which was introduced in an original two-chambered bioreactor asymmetrically fed in a batch mode with a mixture of glucose and xylose in a ratio of 35:15. The two sugars were consumed simultaneously. All glucose was fermented but only 20% of xylose.

Immobilization induces alterations in the outer membrane protein pattern of Yersinia ruckeri.

We compared the outer membrane protein (OMP) pattern of 2-day-old immobilized Yersinia ruckericells (IC) with that of early (FC24) and late (FC48) stationary-phase planktonic counterparts. Fifty-five OMPs were identified. Principal component analysis discriminated between the protein maps of FC and IC.

Molecular weight characteristics of alginate produced by Azotobacter vinelandii in a membrane bioreactor.

A membrane bioreactor which combines a continuous fermentor and a cross-flow microfiltration module enabling continuous cell recycling and removal of the fermentation products freed of microbial cells was tested for the production of alginate by Azotobacter vinelandii. The molecular weight characteristics of the polysaccharide produced were investigated. The macromolecular characteristics of alginate recovered by first filtering batch fermentation broths through different microporous ceramic membranes with pore sizes varying from 0.

Sugar beet Ca-pectate gel as a cost-effective immobilized-cell matrix for metal biosorption.

Whole bacterial (Pseudomonas putida) and yeast (Saccharomyces cerevisiae) cells were immobilized by entrapment in gel beads of Ca-pectate obtained from sugar beet pulp and gel beads of commercial Ca-alginate (of algal origin). These immobilized-cell particles were tested for Cd2+ removal from dilute aqueous solutions and their mechanical properties were evaluated. Only Ca-pectate gel beads loaded with yeast cells displayed enhanced cadmium-binding efficiency (13.

Immobilized viable microbial cells: from the process to the proteome em leader or the cart before the horse.

Biotechnological processes based on immobilized viable cells have developed rapidly over the last 30 years. For a long time, basic studies of the physiological behaviour of immobilized cells (IC) have remained in the shadow of the applications. Natural IC structures, i.

Proteomic analysis of agar gel-entrapped Pseudomonas aeruginosa.

We have compared the protein maps of agar-entrapped Pseudomonas aeruginosa cells to those of free counterparts grown in the presence or absence of the immobilized-cell gel support. Principal component analyses (PCAs) were used to interpret spot quantity variations observed on electropherograms obtained by two-dimensional gel electrophoresis. PCA of the data matrix (923 rows x 6 columns) in which spot density values were standardized horizontally extracted three principal components (PCs) with eigenvalues higher than 1, accounting together for 71.

Comparative proteomic analysis of planktonic and immobilized Pseudomonas aeruginosa cells: a multivariate statistical approach.

The protein maps of Pseudomonas aeruginosa cells from two natural (attached) and one artificial (gel-entrapped) immobilized-cell (IC) systems, together with their free (suspended) counterparts, were compared after incubation for 18 or 48 h in a minimal salt medium. Principal component analysis (PCA) was used to interpret the variations in protein spot densities that were observed on electropherogram obtained by two-dimensional electrophoresis (2-DE). PCA of the 2-DE data, a matrix of 933 rows (observations, i.

Biofilm proteome: homogeneity or versatility?

The problems associated with biofilm infections in humans result from the distinct characteristics of biofilms, in particular their high level of resistance to antibiotics. One of the hypotheses that have been advanced to explain this resistance to antimicrobials is the phenotypic differentiation of biofilm cells. Although many studies on biofilms have highlighted physiological alterations following the attachment of bacteria to a surface, no studies have explicitly demonstrated a "biofilm" physiology.

Occurrence of sessile Pseudomonas oryzihabitans from a karstified chalk aquifer.

Pseudomonas oryzihabitans is an uncommon pathogen that may cause opportunistic infections. Although it has been previously isolated from the environment, the source of human infection has not been well documented. In this study, we describe the presence of P.

Multiple regression modelling of mineral base oil biodegradability based on their physical properties and overall chemical composition.

A set of 38 mineral base oils was characterized by a number of chemical (i.e., overall chemical composition) and physical parameters used routinely in industry.

Substituting Coomassie Brilliant Blue for bromophenol blue in two-dimensional electrophoresis buffers improves the resolution of focusing patterns.

In a new area of postgenomics challenges, the optimization of protein identification has become a central goal in microbiochemistry. In this work, we demonstrate that the substitution of Coomassie Brilliant Blue for bromophenol blue in two-dimensional electrophoresis (2-DE) buffers improves the focusing of whole proteins from Pseudomonas aeruginosa. This improvement of focusing concerns more particularly basic proteins.

Occurrence and phenotypic characterization of Yersinia ruckeri strains with biofilm-forming capacity in a rainbow trout farm.

The presence of Yersinia ruckeri in a French fish farm was investigated. Y. ruckeri was isolated mainly from algae and sediment samples rather than from water.

Phosphate deprivation is associated with high resistance to latamoxef of gel-entrapped, sessile-like Escherichia coli cells.

Viable Escherichia coli cells were entrapped in agar gel layers and incubated in a phosphate-limited glucose medium. Immobilized bacteria displayed enhanced alkaline phosphatase activity and overexpressed the outer membrane protein PhoE as compared with free-floating organisms. These observations highlighted the existence of high phosphate deprivation within biofilm-like structures.

Primary biodegradability of mineral base oils in relation to their chemical and physical characteristics.

The primary biodegradability of 32 mineral base (i.e., unformulated) oils of paraffinic nature was evaluated using the CEC L-33-A-93 test.

Viscosity properties of mineral paraffinic base oils as a key factor in their primary biodegradability.

The primary biodegradability of two types of paraffinic base oils (solvent and catalytically dewaxed oils) and their blends was evaluated using the CEC L-33-A-93 test. The biodegradability values varied between 10% and 75%. Base oil mixtures displayed varying contents in aromatic and polar compounds and a wide range of kinematic viscosity (KV) values, from roughly 10 to 600 cSt (at 40 degrees C), while their viscosity indices were almost constant (90-100).