Characterization of the carbapenem-resistant clinical reference isolate BAL062 (CC2:KL58:OCL1): resistance properties and capsular polysaccharide structure.

The carbapenem-resistant isolate BAL062 is a clinical reference isolate used in several recent experimental studies. It is from a ventilator-associated pneumonia (VAP) patient in an intensive care unit at the Hospital for Tropical Diseases (HTD), Ho Chi Minh City, Vietnam in 2009. Here, BAL062 was found to belong to the B sub-lineage of global clone 2 (GC2) isolates in the previously reported outbreak (2008 and 2012) of carbapenem-resistant VAP at the HTD.

New lactate- and pyruvate-containing polysaccharide and rhamnomannan with xylose residues from the cell wall of Rathayibacter oskolensis VKM Ac-2121.

The cell wall of endophytic strain Rathayibacter oskolensis VKM Ac-2121 (family Microbacteriaceae, class Actinomycetes) was found to contain neutral and acidic glycopolymers. The neutral polymer is a block-type rhamnomannan partially should be substitutied by xylose residues, [→2)-α-[β-D-Xylp-(1 → 3)]-D-Manp-(1 → 3)-α-D-Rhap-(1→] [→2)-α-D-Manp-(1 → 3)-α-D-Rhap-(1→]. The acidic polymer has branched chain, bearing lactate and pyruvate residues, →4)-α-D-[S-Lac-(2-3)-α-L-Rhap-(1 → 3)]-D-Manp-(1 → 3)-α-D-[4,6-R-Pyr]-D-Galp-(1 → 3)-β-D-Glcp-(1 →.

Glycoengineering directs de novo biomanufacturing of UPEC O21 O-antigen polysaccharide based glycoprotein.

Glycoproteins, in which polysaccharides are usually attached to proteins, are an important class of biomolecules that are widely used as therapeutic agents in clinical treatments for decades. Uropathogenic Escherichia coli (UPEC) O21 has been identified as a serogroup that induces urinary tract infections, with a global increasing number among women and young children. Therefore, there is an urgent need to establish protective vaccines against UPEC infection.

A highly branched novel galactofuranan in the cell wall of Clavibacter tesselarius VKM Ac-1406.

The structures of two cell wall glycopolymers were studied in the plant pathogenic bacterium Clavibacter tesselarius VKM Ac-1406 (family Microbacteriaceae, order Micrococcales, class Actinomycetes). The predominant polymer was a novel (1 → 6)-linked β-d-galactofuranan with a highly branched repeating unit, α-L-Rhap-(1 → 3)-α-D-Galp-(1 → 2)-[α-L-Rhap-(1 → 3)]-α-D-Fucp-(1 →, at O-2 on every second galactofuranose residue. The second polymer present in small amounts was acidic with the repeating unit, →3)-α-D-Galp-(1 → 3)-α-D-[4,6-S-Pyr]-Manp-(1 → 3)-α-D-Manp-[2OAc]-(1→, and was reported in all Clavibacter species investigated to date.

Structural and Serological Characterization of the O Antigen of Clinical Isolates Classified into a New Serogroup, O84.

Two closely related smooth strains, Kr1 and Ks20, were isolated from wound and skin samples, respectively, of two infected patients in central Poland. Serological tests, using the rabbit Kr1-specific antiserum, revealed that both strains presented the same O serotype. Their O antigens are unique among the O serotypes, which had been described earlier, as they were not recognized in an enzyme-linked immunosorbent assay (ELISA) by a set of O1-O83 antisera.

A novel cell wall galactofuranan in Clavibacter phaseoli VKM Ac-2641.

A glycopolymer of novel structure was found in the cell wall of plant pathogen Clavibacter phaseoli VKM Ac-2641 (family Microbacteriaceae, class Actinomycetes). The glycopolymer was (1 → 6)-linked β-d-galactofuranan with side branched trisaccharide, α-D-Manp-(1 → 2)-[α-D-Manp-(1 → 3)]-α-D-Ribf-(1→ at O-2 on every second galactofuranose residue. The galactofuranan structure was established by chemical and NMR spectroscopic methods using one- and two-dimensional techniques H,H COSY, TOCSY, ROESY and H,C HSQC, HMBC.

Complete chemical structure of the K135 capsular polysaccharide produced by Acinetobacter baumannii RES-546 that contains 5,7-di-N-acetyl-8-epipseudaminic acid.

A structurally diverse capsular polysaccharide (CPS) in the outer cell envelope plays an important role in the virulence of the important bacterial pathogen, Acinetobacter baumannii. More than 75 different CPS structures have been determined for the species to date, and many CPSs include isomers of a higher sugar, namely 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acid. Recently, a novel isomer having the d-glycero-l-manno configuration (5,7-di-N-acetyl-8-epipseudaminic acid; 8ePse5Ac7Ac) has been identified in the CPS from A.

NoteIdentification of 5,7-diacetamido-3,5,7,9-tetradeoxy-d-glycero-l-manno-non-2-ulosonic acid (di-N-acetyl-8-epipseudaminic acid) in the capsular polysaccharide of Acinetobacter baumannii Res546.

A structurally diverse capsular polysaccharide that surrounds the bacterial cell plays an important role in virulence of Acinetobacter baumannii, a cause of nosocomial infections worldwide. Various isomers of 5,7-diacylamido-3,5,7,9-tetradeoxynon-2-ulosonic acid have been identified as components of bacterial polysaccharides. In this work, we report on the identification of a new isomer having the d-glycero-l-manno configuration (8-epipseudaminic acid) in the capsular polysaccharide of A.

Cell wall galactofuranan and pyruvate-containing galactomannan in the cell walls of Clavibacter strains.

The cell wall glycopolymer structures of plant-associated strains Clavibacter sp. VKM Ac-1371, Clavibacter sp. VKM Ac-1372 and Clavibacter sp.

A novel ItrA4 d-galactosyl 1-phosphate transferase is predicted to initiate synthesis of an amino sugar-lacking K92 capsular polysaccharide of Acinetobacter baumannii B8300.

The K92 capsular polysaccharide (CPS) from Acinetobacter baumannii B8300 was studied by sugar analysis, Smith degradation, and one- and two-dimensional H and C NMR spectroscopy. The elucidated CPS includes a branched pentasaccharide repeat unit containing one d-Galp and four l-Rhap residues; an atypical composition given that all A. baumannii CPS structures determined to date contain at least one amino sugar.

Novel galactofuranan and pyruvylated galactomannan in the cell wall of Clavibacter michiganensis subsp. michiganensis VKM Ac-1403.

The cell wall of Clavibacter michiganensis subsp. michiganensis VKM Ас-1403 (family Microbacteriaceae, class Actinobacteria) contains two polysaccharides. The first one is neutral (1 → 6) linked galactofuranan in which every second galactofuranose residue in the main chain substituted at position 3 by side trisaccharide, β-D-GlcpNAc-(1 → 3)-α-L-Rhap-(1 → 2)-α-D-Fucp-(1 →.

D-rhamnan and teichuronic acid from the cell wall of Rathayibacter caricis VKM Ac-1799.

The cell wall of Rathayibacter caricis VKM Ac-1799 (family Microbacteriaceae, class Actinobacteria) was found to contain both neutral and acidic glycopolymers. The first one is D-rhamnopyranan with main chain →2)-α-D-Rhap-(1 → 3)-α-D-Rhap-(1→, where a part of 2-substituted residues bears as a side-chain at position 3 α-D-Manp residues or disaccharides α-D-Araf-(1→2)-α-D-Manp-(1 → . The second polymer is a teichuronic acid with a branched repeating units composed of seven monosaccharides →4)-α-[β-D-Manp-(1 → 3)]-D-Glcp-(1 → 4)-β-D-GlcpA-(1 → 2)-β-[4,6Pyr]-D-Manp-(1 → 4)-β-L-Rhap-(1 → 4)-β-D-Glcp-(1 → 4)-β-D-Glcp-(1 → .

K17 capsular polysaccharide produced by Acinetobacter baumannii isolate G7 contains an amide of 2-acetamido-2-deoxy-d-galacturonic acid with d-alanine.

The K17 capsular polysaccharide (CPS) produced by Acinetobacter baumannii G7, which carries the KL17 configuration at the capsule biosynthesis locus, was isolated and studied by chemical methods along with one- and two-dimensional H and C NMR spectroscopy. Selective cleavage of the glycosidic linkage of a 2,4-diacetamido-2,4,6-trideoxy-d-glucose (d-QuiNAc4NAc) residue by (i) trifluoroacetic acid solvolysis or (ii) alkaline β-elimination (NaOH-NaBH) of the 4-linked D-alanine amide of a 2-acetamido-2-deoxy-d-galacturonic acid residue (d-GalNAcA6DAla) yielded trisaccharides that were isolated by Fractogel TSK HW-40 gel-permeation chromatography and identified by using NMR spectroscopy and high-resolution electrospray ionization mass spectrometry. The following structure was established for the trisaccharide repeat (K unit) of the CPS: →4)-α-d-GalpNAcA6dAla-(1→4)-α-d-GalpNAcA-(1→3)-β-d-QuipNAc4NAc-(1→ .

Escherichia albertii EA046 (O9) harbors two polysaccharide gene clusters for synthesis of the O-antigen by the Wzx/Wzy-dependent pathway and a mannan shared by Escherichia coli O8 by the Wzm/Wzt-dependent pathway.

O antigen is a polysaccharide chain of a lipopolysaccharide on the outer membrane of Gram-negative bacteria. O-antigen-based serotyping and molecular typing are widely used for epidemiological and surveillance purposes. Two polysaccharides were isolated by Sephadex G-50 gel-permeation chromatography following mild acid degradation of the lipopolysaccharide of Escherichia albertii EA046 assigned to serotype O9.

New glycopolymers containing both D- and L-rhamnopyranoses from Rathayibacter iranicus VKM Ac-1602 cell wall.

The cell wall of Rathayibacter iranicus VKM Ac-1602 (family Microbacteriaceae, class Actinobacteria) is characterised by the absence of phosphate-containing and by the presence of two rhamnose-containing glycopolymers. The first is a branched rhamnomannan, in which 60% of mannose residues of the main chain are glycosylated by terminal mannose residues: →2)-α-D-Rhap-(1 → 3)-α-[α-D-Manp-(1 → 6)]-D-Manp-(1 → . The second is a branched teichuronic acid, in which all the rhamnose residues of the main chain are glycosylated by glucose residues:→3)-α-[α-D-Glcp-(1 → 2)]-L-Rhap-(1 → 4)-β-D-GlcpA-(1 → 2)-α-D-Manp-(1 → 3)-α-D-Galp-(1 → 3)-β-D-Glcp-(1 → .

The K90 capsular polysaccharide produced by Acinetobacter baumannii LUH5553 contains di-N-acetylpseudaminic acid and is structurally related to the K7 polysaccharide from A. baumannii LUH5533.

Acinetobacter baumannii isolate LUH5553 carries the KL90 capsule gene cluster, which includes genes for three glycosyltransferases (Gtrs) and the ItrA3 initiating transferase, as well as a set of genes for synthesis of a higher sugar, 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-l-manno-non-2-ulosonic (di-N-acetylpseudaminic) acid (Pse5Ac7Ac). The K90 capsular polysaccharide (CPS) has a tetrasaccharide repeat (K90 unit), which begins with d-GlcpNAc and contains Pse5Ac7Ac. The higher sugar was cleaved by mild acid hydrolysis of the CPS, and structures of the initial and modified polysaccharides were established by 1D and 2D H and C NMR spectroscopy.

Structural studies on the O-polysaccharide of Escherichia coli O57.

Mild acid hydrolysis of the lipopolysaccharide of Escherichia coli O57 afforded an O-polysaccharide, which was isolated by gel permeation chromatography (GPC) and studied by sugar analysis, Smith degradation and solvolysis with trifluoroacetic acid, along with 2D H and C NMR spectroscopy. The O-polysaccharide was found to contain d-Glc, d-Gal, d-GalA, d-GlcNAc, and l-FucNAc, as well as O-acetyl groups. Smith degradation of the O-deacetylated polysaccharide destroyed side-branch β-Glсp and α-GalpA to give a modified linear polysaccharide.

Structural and genetic relatedness of the O-antigens of Escherichia coli O50 and O2.

An O-specific polysaccharide (O-antigen) was isolated by mild acid degradation of the lipopolysaccharide of Escherichia coli O50 followed by gel chromatography on Sephadex G-50. The following structure of the tetrasaccharide repeat was established by sugar analysis and 1D and 2D H and C NMR spectroscopy: →3)-α-l-Rhap-(1 → 2)-α-l-Rhap-(1 → 3)-β-l-Rhap-(1 → 4)-β-d-GlcpNAc-(1→ The linear O50 polysaccharide has the same structure as the main chain of the branched O polysaccharide of E. coli O2 studied earlier [Jansson et al.

Structure and gene cluster of the O-antigen of Escherichia coli O54.

Mild acid hydrolysis of the lipopolysaccharide of Escherichia coli O54 afforded an O-polysaccharide, which was studied by sugar analysis, solvolysis with anhydrous trifluoroacetic acid, and H and C NMR spectroscopy. Solvolysis cleaved predominantly the linkage of β-d-Ribf and, to a lesser extent, that of β-d-GlcpNAc, whereas the other linkages, including the linkage of α-l-Rhap, were stable under selected conditions (40 °C, 5 h). The following structure of the O-polysaccharide was established: →4)-α-d-GalpA-(1 → 2)-α-l-Rhap-(1 → 2)-β-d-Ribf-(1 → 4)-β-d-Galp-(1 → 3)-β-d-GlcpNAc-(1→ The O-antigen gene cluster of E.

Studies on the O-polysaccharide of Escherichia albertii O2 characterized by non-stoichiometric O-acetylation and non-stoichiometric side-chain l-fucosylation.

An O-polysaccharide was isolated from the lipopolysaccharide of Escherichia albertii O2 and studied by chemical methods and 1D and 2D H and C NMR spectroscopy. The following structure of the O-polysaccharide was established: . The O-polysaccharide is characterized by masked regularity owing to a non-stoichiometric O-acetylation of an l-fucose residue in the main chain and a non-stoichiometric side-chain l-fucosylation of a β-GlcNAc residue.

Structure and genetics of a glycerol 2-phosphate-containing O-specific polysaccharide of Escherichia coli O33.

An O-specific polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Escherichia coli O33 followed by gel-permeation chromatography on Sephadex G-50. The polysaccharide was found to contain glycerol 2-phosphate (Gro-2-P), and the following structure of its tetrasaccharide repeat was established by sugar analysis, dephosphorylation, and 1D and 2D H and C NMR spectroscopy: The O33-antigen gene cluster was analyzed and found to be essentially consistent with the O-polysaccharide structure.

Structure elucidation of the O-specific polysaccharide by NMR spectroscopy and selective cleavage and genetic characterization of the O-antigen of Escherichia albertii O5.

The O-specific polysaccharide (O-antigen) was obtained by mild acid degradation of the lipopolysaccharide of Escherichia albertii O5 (strain T150248) and studied by sugar analysis, selective cleavages of glycosidic linkages, and 1D and 2D H and C NMR spectroscopy. Partial solvolysis with anh (anhydrous) CFCOH and hydrolysis with 0.05 M CFCOH cleaved predominantly the glycosidic linkage of β-GalpNAc or β-Galf, respectively, whereas the linkages of α-GlcpNAc and β-Galp were stable.

Pyruvylated cell wall glycopolymers of Promicromonospora citrea VKM A≿-665 and Promicromonospora sp. VKM A≿-1028.

The cell walls of two strains of the genus Promicromonospora (phylum Actinobacteria) were found to include non-phosphorylated anionic glycopolymers with pyruvic acid acetals of R-configuration. The cell wall of the type strain P. citrea 665 contains two glycopolymers of the sort, including the Kdn-teichulosonic acid with the repeating unit →6)-α-d-Gl≿p/→6)-α-d-Gl≿p3SO-(1 → 4)-α-[7,9Pyr]-Kdn-(2→, and the galactan with the repeating unit →3)-α-[4,6Pyr]-d-Galp-2OAc-(1 → .

Structures and gene clusters of the O-antigens of Escherichia albertii O3, O4, O6, and O7.

The O-specific polysaccharides (OPSs) called O-antigens were obtained by mild acid degradation of the lipopolysaccharides of Escherichia albertii serotypes O3, O4, O6, and O7 and studied by sugar analysis along with 1D and 2D H and C NMR spectroscopy. The following structure was established for the OPS of E. albertii O4, which, to our knowledge, is unique among known bacterial polysaccharide structures: →2)-α-l-Rhap-(1 → 2)-α-l-Fucp-(1 → 2)-β-d-Galp-(1 → 3)-α-d-GalpNAc-(1 → 3)-β-d-GlcpNAc-(1→ The OPS structure of the strain of E.

Structures of the K35 and K15 capsular polysaccharides of Acinetobacter baumannii LUH5535 and LUH5554 containing amino and diamino uronic acids.

Capsular polysaccharides were isolated from A. baumannii LUH5535 (K35 CPS) and LUH5554 (K15 CPS) and studied by 1D and 2D H and C NMR spectroscopy. The CPSs were found to consist of linear tetrasaccharide repeats (K units) containing 2-acetamido-2-deoxy-d-galacturonic acid (K35) or 2,3-diacetamido-2,3-deoxy-d-glucuronic acid (K15) and 2,4-diacetamido-2,4,6-trideoxy-d-glucose (both CPSs).