Versatility of the Burkholderia cepacia complex for the biosynthesis of exopolysaccharides: a comparative structural investigation.

The Burkholderia cepacia Complex assembles at least eighteen closely related species that are ubiquitous in nature. Some isolates show beneficial potential for biocontrol, bioremediation and plant growth promotion. On the contrary, other strains are pathogens for plants and immunocompromised individuals, like cystic fibrosis patients.

Structure of a novel exopolysaccharide produced by Burkholderia vietnamiensis, a cystic fibrosis opportunistic pathogen.

Burkholderia vietnamiensis belongs to the Burkholderia cepacia complex and is an opportunistic pathogen for cystic fibrosis patients. As many other Burkholderia species, it has a mucoide phenotype, producing abundant exopolysaccharide. In general, polysaccharides contribute to bacterial survival in a hostile environment, are recognised as virulence factors and as important components in biofilm formation.

Antibonding plasmon modes in colloidal gold nanorod clusters.

The optical response of nanoplasmonic colloids in disperse phase is strictly related to their shape. However, upon self-assembly, new optical features, for example, bonding or antibonding modes, emerge as a result of the mutual orientations of nanoparticles. The geometry of the final assemblies often determines which mode is dominating in the overall optical response.

A selective assay to detect chitin and biologically active nano-machineries for chitin-biosynthesis with their intrinsic chitin-synthase molecules.

A new assay system for chitin has been developed. It comprises the chitin-binding protein ChbB in fusion with a His-tag as well as with a Strep-tag, the latter of which was chemically coupled to horseradish peroxidase. With the resulting complex, minimal quantities of chitin are photometrically detectable.

Macromolecular properties of cepacian in water and in dimethylsulfoxide.

Cepacian is the exopolysaccharide produced by the majority of the so far investigated clinical strains of the Burkholderia cepacia complex. This is a group of nine closely related bacterial species that might cause serious lung infections in cystic fibrosis patients, in some cases leading to death. In this paper the aggregation ability and the conformational properties of cepacian chain were investigated to understand its role in biofilm formation.

Exopolysaccharides produced by Inquilinus limosus, a new pathogen of cystic fibrosis patients: novel structures with usual components.

The major cause of morbidity and mortality in patients with cystic fibrosis, an autosomal recessive disorder, is chronic microbial colonisation of the major airways that leads to exacerbation of pulmonary infection. Several different microbes colonise cystic fibrosis lungs, and Pseudomonas aeruginosa is one of the most threatening, since the establishment of mucoid (alginate producing) strains is ultimately associated with the patient's death. Very recently a new bacterium, named Inquilinus limosus, was repeatedly found infecting the respiratory tract of cystic fibrosis patients.

Exopolysaccharides produced by clinical strains belonging to the Burkholderia cepacia complex.

Background: In the frame of a research line dedicated to better clarify the role of exopolysaccharides (EPS) in bacterial virulence, EPS produced by species of the Burkholderia cepacia complex (Bcc), namely Burkholderia multivorans, Burkholderia cenocepacia, and a Bcc member of undetermined genomovar, all isolated at the Cystic Fibrosis Regional Centre of Florence (Italy), were investigated for they structural properties.

Methods: Three strains of B. multivorans, three of B.

First report of a lyase for cepacian, the polysaccharide produced by Burkholderia cepacia complex bacteria.

Bacteria belonging to the Burkholderia cepacia complex (Bcc) are interesting for their involvement in pulmonary infections in patients affected by cystic fibrosis (CF) or chronic granulomatous disease. Many Bcc strains isolated from CF patients produce high amounts of exopolysaccharides (EPS). Although different strains sometimes biosynthesise different EPS, the majority of Bcc bacteria produce only one type of polysaccharide, which is called cepacian.

Interaction of antimicrobial peptides with bacterial polysaccharides from lung pathogens.

The interaction of two cathelicidin antimicrobial peptides, LL-37 and SMAP-29, with three bacterial polysaccharides, respectively, produced by Pseudomonas aeruginosa, Burkholderia cepacia and Klebsiella pneumoniae, was investigated to identify possible mechanisms adopted by lung pathogens to escape the action of innate immunity effectors. In vitro assays indicated that the antibacterial activity of both peptides was inhibited to a variable extent by the three polysaccharides. Circular dichroism experiments showed that these induced an alpha-helical conformation in the two peptides, with the polysaccharides from K.

Exopolysaccharides produced by Burkholderia cenocepacia recA lineages IIIA and IIIB.

Clinical and environmental strains of Burkholderia cenocepacia belonging to the recA lineages IIIA and IIIB were examined for exopolysaccharide (EPS) production. The exopolysaccharides structure was determined using mainly gas chromatography coupled to mass spectrometry and NMR spectroscopy. All the strains produced Cepacian, a highly branched polysaccharide constituted of a heptasaccharide repeating unit, composed of one rhamnose, one glucose, one glucuronic acid, one mannose and three galactose residues.

Exopolysaccharides produced by a clinical strain of Burkholderia cepacia isolated from a cystic fibrosis patient.

Burkholderia cepacia is an opportunistic pathogen involved in pulmonary infections related to cystic fibrosis. A clinical strain, BTS13, was isolated and the production of exopolysaccharides was tested growing the bacteria on two different media, one of which was rich in mannitol as carbon source. The primary structure of the polysaccharides was determined using mostly mass spectrometry and NMR spectroscopy.