Genome Sequence of E. coli O104:H4 Leads to Rapid Development of a Targeted Antimicrobial Agent against This Emerging Pathogen

A recent widespread outbreak of Escherichia coli O104:H4 in Germany demonstrates the dynamic nature of emerging and re-emerging food-borne pathogens, particularly STECs and related pathogenic E. coli. Rapid genome sequencing and public availability of these data from the German outbreak strain allowed us to identify an O-antigen-specific bacteriophage tail spike protein encoded in the genome. We synthesized this gene and fused it to the tail fiber gene of an R-type pyocin, a phage tail-like bacteriocin, and expressed the novel bacteriocin such that the tail fiber fusion was incorporated into the bacteriocin structure. The resulting particles have bactericidal activity specifically against E. coli strains that produce the O104 lipopolysaccharide antigen, including the outbreak strain. This O-antigen tailspike-R-type pyocin strategy provides a platform to respond rapidly to emerging pathogens upon the availability of the pathogen's genome sequence

Core region of Citrobacter lipopolysaccharide from strain PCM 1487 Structure elucidation by two‐dimensional 1H‐NMR spectroscopy at 500 MHz and methylation analysis/mass spectrometry

The core structure of Citrobacter PCM 1487 lipopolysaccharide has been established using methylation analysis/mass spectrometry, chemical degradations and one- and two-dimensional 1H-NMR spectroscopy at 500 MHz. 1H-NMR assignments are given for all sugar components of the core oligosaccharide. In the formula shown below, the alternative locations of branch terminal heptose (LDHep) and diphosphorylethanolamine (PPEtN) residues are marked by dashed lines; dOclA stands for 3-deoxy-D-manno-octulosonic acid. (Formula: see text). The sample of the core oligosaccharide showed some microheterogeneity due to a slightly incomplete substitution by terminal N-acetylgalactosamine and a partial splitting of diphosphorylethanolamine residues

3-Deoxy-octulosonic Acid-Containing Trisaccharide Fragment of an Unusual Core Type of Some Hafnia alvei Lipopolysaccharides

The 3-deoxy-octulosonic acid-containing trisaccharide was isolated from the carbohydrate material obtained after the acid hydrolysis of lipopolysaccharides of Hafnia alvei strains 2 and 1211 using gel filtration. For purification the trisaccharide fraction was rechromatographed on a Bio-Gel P2 column. On the basis of sugar and methylation analyses and 1H NMR spectroscopy the trisaccharide was identified as 3-deoxy-7-O-(6-O-acetyl-alpha-D-galactopyranosyl)-4-O-(alpha-L-glycero-D - mannoheptopyranosyl)-D-manno-2-octulopyranosic acid. The occurrence of such bifurcate Kdo-containing structure has not been previously reported in Enterobacteriaceae

Structure elucidation of the core octasaccharide from Citrobacter PCM 1487 with the aid of 500-MHz, two-dimensional phase-sensitive correlated, relayed-coherence transfer, double-quantum, triple-quantum filtered, and N.O.E. 1H-n.m.r. spectra

The main features of the primary structure of the octasaccharide, α-d-Glcp-(1→2)-α-d-Glcp-(1→2)-[α-d-GalpNAc- (1→3)]-α-d-Galp-(1→3)-α-d-Glcp-(1→3)-[α-ld-Hepp-(1→7)]-α-ld-Hepp-(1→3)-α-ld-Hep, have been determined in the ab initio manner by 1H-n.m.r. spectroscopy without resorting to biochemical methods of analysis. Several nontypical interresidue n.O.e. values point to a preferred solution conformation of the molecule

The application of 1H13C inversely correlated NMR spectroscopy to the determination of acylation and glycosylation sites in the O-specific polysaccharide from Hafnia alvei 1187

An inversely correlated NMR spectrum defined the amino sugars acylated by acetyl or 3-hydroxybutyryl groups and revealed partial sequences and glycosylation sites in a tetrasacchride repeating unit of the title polysaccharide, (→2dGlcαl→3dGlcNAcylαl→→4dGalNAcαl→3dGalNAcβl→)n, where Acyl = 3-hydroxybutyryl

O -specific polysaccharides of Hafnia alvei lipopolysaccharides isolated from two serologically related strains: ATCC 13337 and 1187. A serological and structural study using chemical methods, gas chromatography/mass spectrometry and NMR spectroscopy at 500 MHz

The O-specific polysaccharides of Hafnia alvei ATCC 13337 standard strain and 1187 strain have been isolated and characterized. By means of 1H-NMR spectroscopy, methylation analysis and periodate oxidation, the repeating unit of the polysaccharides could be allocated the respective structures. (formula; see text) where Acyl = D-3-hydroxybutyryl, and 3-O-acetylation was to about 66%. The structural similarity of the polysaccharides was confirmed in the serological study; their epitopes were determined and the importance of various structural elements for the serological specificity was discussed