The soil saprophyte Bacillus cereus forms biofilms at solid-liquid interfaces. composition of the extracellular polymeric matrix is not known, but other bacteria are encased in polysaccharides, protein, and also DNA (eDNA). A Tn917 screen for strains impaired biofilm formation a interface yielded several mutants. Three mutants deficient purine biosynthesis genes purA, purC, purL were impaired, they grew planktonically like wild type Luria-Bertani broth. Biofilm populations had higher...

ABSTRACT Bacillus is commonly isolated from soils, with organisms of cereus sensu lato being prevalent. Knowledge the ecology B. and other species in soil far complete. While older literature favors a model growth on soil-associated organic matter, current paradigm that germinates grows association animals or plants, resulting either symbiotic pathogenic interactions. An terra approach to study bacteria described, using filter-sterilized soil-extracted soluble matter (SESOM) artificial...

Bacterial biofilms are predominant in natural ecosystems and constitute a public health threat because of their outstanding resistance to antibacterial treatments especially antibiotics. To date, several systems have been developed grow bacterial order study phenotypes the physiology sessile cells. Although relevant, such permit analysis various aspects biofilm state but often after hours growth.

ABSTRACT Antibiotics such as chlortetracycline (CTC) have been used to promote growth of pigs for decades, but concerns over increased antibiotic-resistant infections in humans prompted the development alternative strategies. Developing alternatives antibiotic promoters (AGPs) could be informed by information on mechanisms promotion, notably, how AGPs affect microbial populations gastrointestinal tract. Pigs from three sows were aseptically delivered cesarean section. Six piglets distributed...

Plasmonic technology relies on the coupling of light to surface electromagnetic modes smooth or structured metal surfaces. While some applications utilise resonant nature polaritons, others require broadband characteristics. We demonstrate unidirectional and plasmonic antennas with large acceptance angles based chirped gratings. Near-field optical measurements have been used visualise excitation plasmon polaritons by such aperiodic structures. These weakly crystals allow formation a trapped...

Biofilms are present in all environments and often result negative effects due to properties of the biofilm lifestyle especially antibiotics resistance. associated with chronic infections. Controlling bacterial attachment, first step formation, is crucial for fighting against subsequently preventing persistence infection. Thus deciphering underlying molecular mechanisms involved attachment could allow discovering targets from it would be possible develop inhibitors colonization potentiate...

Enterohaemorrhagic Escherichia coli, such as serotype O157:H7, are a leading cause of food-associated outbreaks. While the primary reservoir is associated with cattle, plant foods have been sources human infection. E. coli able to grow in tissue food plants spinach. fecal contamination suspect, soil has underestimated potential reservoir. Persistence bacterial populations open systems product growth, death, predation, and competition. Here we report that O157:H7 can using soluble compounds...

We present the realisation of near-field spectroscopic measurements with fibre-tip-based scanning microscopy.It allows simultaneous acquisition images in a broad spectral range (400 nm to 1000 nm), thus recovering local information.This technique is essential order understand resonant interaction light nanostructured material as far-field and nearfield response can differ significantly, e.g., case plasmonic nanostructures.Several example applications hyperspectral imaging are given for...

Abstract Integrated plasmonic sources and detectors are imperative in the practical development of circuitry for bio- chemical sensing, nanoscale optical information processing, as well transducers high-density data storage. Here we show that vertical-cavity surface-emitting lasers (VCSELs) can be employed an on-chip, electrically pumped source or detector signals, when operated forward reverse bias, respectively. To this end, experimentally demonstrate surface plasmon polariton excitation,...

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

Bacterial biofilms are complex cell communities found attached to surfaces and surrounded by an extracellular matrix composed of exopolysaccharides, DNA, proteins. We investigated the whole-genome expression profile Pseudomonas aeruginosa sessile cells (SCs) present in developed on a glass wool substratum. The transcriptome proteome SCs were compared with those planktonic cultures. Principal component analysis revealed biofilm-specific gene profile. Our study highlighted overexpression genes...

Biofilm bacteria are widely held to exhibit a unique phenotype, typified by their increased resistance antimicrobial agents. Numerous studies have been devoted the identification of biofilm-specific genes, but surprisingly few reported date. We compared whole cell proteomes 24 h old Bacillus cereus biofilms and associated suspended population exponential, transient stationary phase planktonic cultures using unbiased approach principal component analysis, comparing quantity variations 823...

Abstract Understanding the molecular basis of resistance to imatinib, a tyrosine kinase inhibitor used as front‐line therapy in chronic myeloid leukemia, remains challenge for successful treatment. In an attempt identify new mechanisms resistance, we performed comparative proteomic analysis imatinib‐resistant cell line generated from erythroblastic K562 (K562‐r) which no known mechanism has been detected. Bidimensional gel electrophoresis was carried out compare protein expression pattern...

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

Changes in leaf soluble proteome were explored 3-month-old plants of metallicolous (M) and nonmetallicolous (NM) Agrostis capillaris L. populations exposed to increasing Cu concentrations (1-50 μM) investigate molecular mechanisms underlying plant responses excess tolerance M plants. Plants cultivated on perlite (CuSO4 spiked-nutrient solution). Soluble proteins, extracted by the trichloroacetic acid/acetone procedure, separated with 2-DE (linear 4-7 pH gradient). Analysis CCB-stained gels...

Lipopolysaccharides (LPS) constitute the outermost layer of Gram-negative bacteria and consequently play an important role in bacterial infections. In order to address public health issues posed by bacteria, it is necessary elucidate structure molecular actors at forefront LPS virulence toxicity are partially modulated lipid A, a hydrophobic saccharolipid that anchors outer membrane. Understanding A inherently intertwined with understanding its as endotoxin. Accordingly, several successful...

Esca is one of the major diseases affecting vineyards with direct impact on product yield; nevertheless, scientific studies concerning its grape quality are scarce. As an attempt to better understand mechanisms behind "Esca proper" development in grapes, this work focused identification proteins whose expression altered by disease. 2-DEs were performed protein extracts from skins at different stages maturity for two consecutive vintages. Grapes collected 2009 and 2010 plants that did not...

Biofilms have significance in medical, industrial, and environmental settings, can cause important damage. As biofilms are tolerant to various stresses, including antibiotics, it is necessary better understand their formation. For this reason, we characterized the phospholipidome of Pseudomonas aeruginosa, an opportunistic pathogen involved numerous infections, during first steps biofilm development. By a liquid chromatography-tandem mass spectrometry time-course analysis over 24-h period,...

In a new area of postgenomics challenges, the optimization protein identification has become central goal in microbiochemistry. this work, we demonstrate that substitution Coomassie Brilliant Blue for bromophenol blue two-dimensional electrophoresis (2-DE) buffers improves focusing whole proteins from Pseudomonas aeruginosa. This improvement concerns more particularly basic proteins. enhancement may be attributed to better transfer first second dimension, which probably highlights an...

Antibiotics have traditionally been used for growth promotion in the pork industry; however, their use animal feed has recently limited because of human health concerns. The intestinal microbiota plays an important role mediating many physiological functions such as digestion and growth. It was hypothesized that antibiotics promotants subsequent variations induce significant changes glycoconjugate composition, which ultimately affects disease susceptibility. aim this study to characterize...