Anti-Biofilm Extracts and Molecules from the Marine Environment.

Pathogenic bacteria and their biofilms are involved in many diseases and represent a major public health problem, including the development of antibiotic resistance. These biofilms are known to cause chronic infections for which conventional antibiotic treatments are often ineffective. The search for new molecules and innovative solutions to combat these pathogens and their biofilms has therefore become an urgent need.

Cultivable epiphytic bacteria of the Chlorophyta Ulva sp.: diversity, antibacterial, and biofilm-modulating activities.

Aims: Macroalgae harbor a rich epiphytic microbiota that plays a crucial role in algal morphogenesis and defense mechanisms. This study aims to isolate epiphytic cultivable microbiota from Ulva sp. surfaces.

Extracts from Wallis Sponges Inhibit Biofilm Formation.

Pathogenic bacteria and their biofilms are involved in many human and animal diseases and are a major public health problem with, among other things, the development of antibiotic resistance. These biofilms are known to induce chronic infections for which classical treatments using antibiotic therapy are often ineffective. Sponges are sessile filter-feeding marine organisms known for their dynamic symbiotic partnerships with diverse microorganisms and their production of numerous metabolites of interest.

Mechanically Enhanced Salmo salar Gelatin by Enzymatic Cross-linking: Premise of a Bioinspired Material for Food Packaging, Cosmetics, and Biomedical Applications.

Marine animal by-products of the food industry are a great source of valuable biomolecules. Skins and bones are rich in collagen, a protein with various applications in food, cosmetic, healthcare, and medical industries in its native form or partially hydrolyzed (gelatin). Salmon gelatin is a candidate of interest due to its high biomass production available through salmon consumption, its biodegradability, and its high biocompatibility.

Microbiota of the Digestive Glands and Extrapallial Fluids of Clams Evolve Differently Over Time Depending on the Intertidal Position.

The Manila clam (Ruditapes philippinarum) is the second most exploited bivalve in the world but remains threatened by diseases and global changes. Their associated microbiota play a key role in their fitness and acclimation capacities. This study aimed at better understanding the behavior of clam digestive glands and extrapallial fluids microbiota at small, but contrasting spatial and temporal scales.

The marine intertidal zone shapes oyster and clam digestive bacterial microbiota.

Digestive microbiota provide a wide range of beneficial effects on host physiology and are therefore likely to play a key role in marine intertidal bivalve ability to acclimatize to the intertidal zone. This study investigated the effect of intertidal levels on the digestive bacterial microbiota of oysters (Crassostrea gigas) and clams (Ruditapes philippinarum), two bivalves with different ecological niches. Based on 16S rRNA region sequencing, digestive glands, seawater and sediments harbored specific bacterial communities, dominated by operational taxonomic units assigned to the Mycoplasmatales,Desulfobacterales and Rhodobacterales orders, respectively.

Novel Antifungal Compounds, Spermine-Like and Short Cyclic Polylactates, Produced by in Yogurt.

was described as endowed with high antifungal activity. Most of the studies associated this activity to the produced organic acids, i.e.

Action mechanisms involved in the bioprotective effect of Lactobacillus harbinensis K.V9.3.1.Np against Yarrowia lipolytica in fermented milk.

The use of lactic acid bacteria (LAB) as bioprotective cultures can be an alternative to chemical preservatives or antibiotic to prevent fungal spoilage in dairy products. Among antifungal LAB, Lactobacillus harbinensis K.V9.

Identification and quantification of antifungal compounds produced by lactic acid bacteria and propionibacteria.

Fungal growth in bakery products represents the most frequent cause of spoilage and leads to economic losses for industrials and consumers. Bacteria, such as lactic acid bacteria and propionibacteria, are commonly known to play an active role in preservation of fermented food, producing a large range of antifungal metabolites. In a previous study (Le Lay et al.

Screening for antimicrobial and proteolytic activities of lactic acid bacteria isolated from cow, buffalo and goat milk and cheeses marketed in the southeast region of Brazil.

Lactic acid bacteria (LAB) can be isolated from different sources such as milk and cheese, and the lipolytic, proteolytic and glycolytic enzymes of LAB are important in cheese preservation and in flavour production. Moreover, LAB produce several antimicrobial compounds which make these bacteria interesting for food biopreservation. These characteristics stimulate the search of new strains with technological potential.

Characterization of the antifungal activity of Lactobacillus harbinensis K.V9.3.1Np and Lactobacillus rhamnosus K.C8.3.1I in yogurt.

Few antifungal protective cultures adapted to fermented dairy products are commercially available because of the numerous constraints linked to their market implementation. Consumer's demand for naturally preserved food products is growing and the utilization of lactic acid bacteria is a promising way to achieve this goal. In this study, using a 2(5-1) factorial fractional design, we first evaluated the effects of fermentation time, of initial sucrose concentration and of the initial contamination amount of a spoilage yeast, on antifungal activities of single and mixed cultures of Lactobacillus rhamnosus K.

Screening of Lactobacillus spp. for the prevention of Pseudomonas aeruginosa pulmonary infections.

Background: Pseudomonas aeruginosa is an opportunistic pathogen that significantly increases morbidity and mortality in nosocomial infections and cystic fibrosis patients. Its pathogenicity especially relies on the production of virulence factors or resistances to many antibiotics. Since multiplication of antibiotic resistance can lead to therapeutic impasses, it becomes necessary to develop new tools for fighting P.

Stability and Inhibitory Activity of Pediocin PA-1 Against Listeria sp. in Simulated Physiological Conditions of the Human Terminal Ileum.

Listeria monocytogenes is responsible for severe foodborne infections, which can be life-threatening especially for infants and elderly populations. The emergence of antibiotic-resistant pathogens has stimulated the search for new strategies, such as the use of bacteriocins, to prevent or cure foodborne infectious diseases in the intestine. In this study, we evaluated the efficacy of the bacteriocin pediocin PA-1 from Pediococcus acidilactici UL5 to inhibit Listeria ivanovii, used as a surrogate for L.

Antimicrobial potential of egg yolk ovoinhibitor, a multidomain Kazal-like inhibitor of chicken egg.

Chicken egg ovoinhibitor is a multidomain Kazal-type serine protease inhibitor with unknown function. Comparison of expression between different tissues indicated that ovoinhibitor is highly expressed in the magnum and liver followed by the uterus, which secrete egg white, egg yolk, and eggshell precursors, respectively. The results also revealed that ovoinhibitor expression is increased in the liver during sexual maturation followed by a subsequent decrease in mature hens.

Set up of a new in vitro model to study dietary fructans fermentation in formula-fed babies.

A new in vitro fermentation model with immobilised infant faecal microbiota simulating the proximal colon of a formula-fed baby was developed and used to test the effects of known prebiotic fructans. Intestinal fermentation, based on a previously developed colonic fermentation model, using a new feeding medium simulating a formula-fed infant ileal chyme, was carried out for seventy-one consecutive days divided into four stabilisation periods intercalated with four prebiotic treatment periods. At the end of the first stabilisation period, total bacterial concentration in colonised beads and in faecal sample was similar, metabolite concentrations returned to stabilisation values after each treatment period.

New in vitro colonic fermentation model for Salmonella infection in the child gut.

In this study, a new in vitro continuous colonic fermentation model of Salmonella infection with immobilized child fecal microbiota and Salmonella serovar Typhimurium was developed for the proximal colon. This model was then used to test the effects of two amoxicillin concentrations (90 and 180 mg day(-1)) on the microbial composition and metabolism of the gut microbiota and on Salmonella serovar Typhimurium during a 43-day fermentation. Addition of gel beads (2%, v/v) colonized with Salmonella serovar Typhimurium in the reactor resulted in a high and stable Salmonella concentration (log 7.

Glycerol induces reuterin production and decreases Escherichia coli population in an in vitro model of colonic fermentation with immobilized human feces.

Lactobacillus reuteri ATCC 55730 is a probiotic strain that produces, in the presence of glycerol, reuterin, a broad-spectrum antimicrobial substance. This strain has been shown to prevent intestinal infections in vivo; however, its mechanisms of action, and more specifically whether reuterin production occurs within the intestinal tract, are not known. In this study, the effects of L.

Inhibitory activity spectrum of reuterin produced by Lactobacillus reuteri against intestinal bacteria.

Background: Reuterin produced from glycerol by Lactobacillus reuteri, a normal inhabitant of the human intestine, is a broad-spectrum antimicrobial agent. It has been postulated that reuterin could play a role in the probiotic effects of Lb. reuteri.

Safety assessment of dairy microorganisms: Propionibacterium and Bifidobacterium.

The genera Propionibacterium and Bifidobacterium are clustered in the class Actinobacteria and form the anaerobic branch of coryneform bacteria. The dairy propionibacteria comprising four species P. freudenreichii, P.

New three-stage in vitro model for infant colonic fermentation with immobilized fecal microbiota.

The development and validation of a new three-stage culture system with immobilized fecal microbiota to simulate infant colonic ecosystem is described. Two continuous cultures with different fecal inocula were used to assess the validity and stability of the intestinal model. The total anaerobe populations measured in beads and effluent fermentations reached high concentrations similar to infant feces.

Comparative effects of exopolysaccharides from lactic acid bacteria and fructo-oligosaccharides on infant gut microbiota tested in an in vitro colonic model with immobilized cells.

The aim of this study was to compare the effects of purified exopolysaccharides from Lactobacillus rhamnosus RW-9595M with those of a well-known prebiotic (short-chain fructo-oligosaccharides) on infant colonic microbiota using a new three-stage chemostat model with immobilized infant faecal microbiota. Two continuous cultures with different faecal inocula were tested with different compositions of carbohydrate media. During the first fermentation (F1), fructo-oligosaccharides tested at a concentration of 9.

Comparative detection of bacterial adhesion to Caco-2 cells with ELISA, radioactivity and plate count methods.

Different methods are used to study bacterial adhesion to intestinal epithelial cells, which is an important step in pathogenic infection as well as in probiotic colonization of the intestinal tract. The aim of this study was to compare the ELISA-based method with more conventional plate count and radiolabeling methods for bacterial adhesion detection. An ELISA-based assay was optimized for the detection of Bifidobacterium longum and Escherichia coli O157:H7, which are low and highly adherent bacteria, respectively.

In vitro inhibition of Escherichia coli O157:H7 by bifidobacterial strains of human origin.

The ability of bifidobacteria isolated from infant feces to inhibit enterohemorrhagic Escherichia coli serotype O157:H7 in vitro and reduce its adhesion to human enterocyte-like Caco-2 cells was evaluated in comparison to American Type Culture Collection bifidobacterial reference strains. Five Bifidobacterium isolates from infant feces were identified and characterized by morphology, fructose-6-phosphate phosphoketolase (F6PPK) assay, polymerase chain reaction using bifidobacterial 16S rDNA specific primers, carbohydrate fermentation patterns, resistance to lysozyme, acid, bile and hydrogen peroxide as well as their ability to inhibit E. coli O157:H7 using the agar spot technique.

Ruminococcus luti sp. nov., isolated from a human faecal sample.

A strain of an unidentified strictly anoxic, gram-postive, non-motile Ruminococcus-like bacterium was isolated from a human faecal sample. The organism used carbohydrates as fermentable substrates, produced acetate, succinate, and hydrogen as the major products of glucose metabolism, and possessed a G + C content of 43.3 mol%.