The O-antigen structure of bacterium Comamonas aquatica CJG

O-antigen is a component of the outer membrane of Gram-negative bacteria and is one of the most variable cell surface constituents, leading to major antigenic variability. The O-antigen forms the basis for bacterial serotyping. In this study, the O-antigen structure of Salmonella O66 was established, which differs from the known O-antigen structure of Escherichia coli O166 only in one linkage (most likely the linkage between the O-units) and O-acetylation. The O-antigen gene clusters of Salmonella O66 and E. coli O166 were found to have similar organizations, the only exception being that in Salmonella O66, the wzy gene is replaced by a non-coding region. The function of the wzy gene in E. coli O166 was confirmed by the construction and analysis of deletion and trans-complementation mutants. It is proposed that a functional wzy gene located outside the O-antigen gene cluster is involved in Salmonella O66 O-antigen biosynthesis, as has been reported previously in Salmonella serogroups A, B and D1. The sequence identity for the corresponding genes between the O-antigen gene clusters of Salmonella O66 and E. coli O166 ranges from 64 to 70 %, indicating that they may originate from a common ancestor. It is likely that after the species divergence, Salmonella O66 got its specific O-antigen form by inactivation of the wzy gene located in the O-antigen gene cluster and acquisition of two new genes (a wzy gene and a prophage gene for O-acetyl modification) both residing outside the O-antigen gene cluster.

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O-antigen structure in a virulent strain ofAeromonas hydrophila

FEMS Microbiology Letters ◽

10.1111/j.1574-6968.1984.tb01319.x ◽

1984 ◽

Vol 24 (2-3) ◽

pp. 277-280 ◽

Cited By ~ 18

Author(s):

Derek H. Shaw ◽

M.Jeanne Squires

Keyword(s):

Virulent Strain ◽

O Antigen ◽

Antigen Structure

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Structural Determination and Genetic Identification of the O-Antigen from an Escherichia coli Strain, LL004, Representing a Novel Serogroup

International Journal of Molecular Sciences ◽

10.3390/ijms222312746 ◽

2021 ◽

Vol 22 (23) ◽

pp. 12746

Author(s):

Jing Wang ◽

Yujuan Xu ◽

Chunjun Qin ◽

Jing Hu ◽

Jian Yin ◽

...

Keyword(s):

Escherichia Coli ◽

Nmr Spectra ◽

Coli Strain ◽

Genetic Identification ◽

Gram Negative Bacteria ◽

Gram Negative ◽

E Coli ◽

O Antigen ◽

Antigen Structure ◽

Dependent Pathway

The O-antigen is the outermost component of the lipopolysaccharide layer in Gram-negative bacteria, and the variation of O-antigen structure provides the basis for bacterial serological diversity. Here, we determined the O-antigen structure of an Escherichia coli strain, LL004, which is totally different from all of the E. coli serogroups. The tetrasaccharide repeating unit was determined as →4)-β-d-Galp-(1→3)-β-d-GlcpNAc6OAc(~70%)-(1→3)-β-d-GalpA-(1→3)-β-d-GalpNAc-(1→ with monosaccharide analysis and NMR spectra. We also characterized the O-antigen gene cluster of LL004, and sequence analysis showed that it correlated well with the O-antigen structure. Deletion and complementation testing further confirmed its role in O-antigen biosynthesis, and indicated that the O-antigen of LL004 is assembled via the Wzx/Wzy dependent pathway. Our findings, in combination, suggest that LL004 should represent a novel serogroup of E. coli.

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O-antigen structure of Shigella flexneri serotype Yv and effect of the lpt-O gene variation on phosphoethanolamine modification of S. flexneri O-antigens

Glycobiology ◽

10.1093/glycob/cws222 ◽

2013 ◽

Vol 23 (4) ◽

pp. 475-485 ◽

Cited By ~ 20

Author(s):

Y. A. Knirel ◽

R. Lan ◽

S. N. Senchenkova ◽

J. Wang ◽

A. S. Shashkov ◽

...

Keyword(s):

Shigella Flexneri ◽

Gene Variation ◽

O Antigen ◽

O Antigens ◽

Antigen Structure

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Increased severity of respiratory infections associated with elevated anti-LPS IgG2 which inhibits serum bactericidal killing

Journal of Experimental Medicine ◽

10.1084/jem.20132444 ◽

2014 ◽

Vol 211 (9) ◽

pp. 1893-1904 ◽

Cited By ~ 38

Author(s):

Timothy J. Wells ◽

Deborah Whitters ◽

Yanina R. Sevastsyanovich ◽

Jennifer N. Heath ◽

John Pravin ◽

...

Keyword(s):

Respiratory Infections ◽

Natural Infection ◽

Gram Negative Bacteria ◽

Inhibitory Antibody ◽

Gram Negative ◽

O Antigen ◽

Excess Production ◽

Blocking Antibodies ◽

Antigen Structure ◽

Induce Antibody

Although specific antibody induced by pathogens or vaccines is a key component of protection against infectious threats, some viruses, such as dengue, induce antibody that enhances the development of infection. In contrast, antibody-dependent enhancement of bacterial infection is largely unrecognized. Here, we demonstrate that in a significant portion of patients with bronchiectasis and Pseudomonas aeruginosa lung infection, antibody can protect the bacterium from complement-mediated killing. Strains that resist antibody-induced, complement-mediated killing produce lipopolysaccharide containing O-antigen. The inhibition of antibody-mediated killing is caused by excess production of O-antigen–specific IgG2 antibodies. Depletion of IgG2 to O-antigen restores the ability of sera to kill strains with long-chain O-antigen. Patients with impaired serum-mediated killing of P. aeruginosa by IgG2 have poorer respiratory function than infected patients who do not produce inhibitory antibody. We suggest that excessive binding of IgG2 to O-antigen shields the bacterium from other antibodies that can induce complement-mediated killing of bacteria. As there is significant sharing of O-antigen structure between different Gram-negative bacteria, this IgG2-mediated impairment of killing may operate in other Gram-negative infections. These findings have marked implications for our understanding of protection generated by natural infection and for the design of vaccines, which should avoid inducing such blocking antibodies.

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The Escherichia coli O111 and Salmonella enterica O35 Gene Clusters: Gene Clusters Encoding the Same Colitose-Containing O Antigen Are Highly Conserved

Journal of Bacteriology ◽

10.1128/jb.182.18.5256-5261.2000 ◽

2000 ◽

Vol 182 (18) ◽

pp. 5256-5261 ◽

Cited By ~ 30

Author(s):

Lei Wang ◽

Peter R. Reeves

Keyword(s):

Escherichia Coli ◽

Gene Cluster ◽

Salmonella Enterica ◽

Gc Content ◽

Gene Clusters ◽

Gram Negative Bacteria ◽

Normal Range ◽

E Coli ◽

O Antigen ◽

Antigen Structure

ABSTRACT O antigen is part of the lipopolysaccharide present in the outer membrane of gram-negative bacteria. Escherichia coli andSalmonella enterica each have many forms of O antigen, but only three are common to the two species. It has been found that, in general, O-antigen genes are of low GC content. This deviation in GC content from that of typical S. enterica or E. coli genes (51%) is thought to indicate that the O-antigen DNA originated in species other than S. enterica or E. coli and was captured by lateral transfer. The O-antigen structure of Salmonella enterica O35 is identical to that of E. coli O111, commonly found in enteropathogenicE. coli strains. This O antigen, which has been shown to be a virulence factor in E. coli, contains colitose, a 3,6-dideoxyhexose found only rarely in theEnterobacteriaceae. Sequencing of the O35-antigen gene cluster of S. enterica serovar Adelaide revealed the same gene order and flanking genes as in E. coli O111. The divergence between corresponding genes of these two gene clusters at the nucleotide level ranges from 21.8 to 11.7%, within the normal range of divergence between S. enterica and E. coli. We conclude that the ancestor of E. coli andS. enterica had an O antigen identical to the O111 and O35 antigens, respectively, of these species and that the gene cluster encoding it has survived in both species.

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Vibrio splendidus O‐antigen structure: a trade‐off between virulence to oysters and resistance to grazers

Environmental Microbiology ◽

10.1111/1462-2920.14996 ◽

2020 ◽

Vol 22 (10) ◽

pp. 4264-4278 ◽

Cited By ~ 2

Author(s):

Daniel Oyanedel ◽

Yannick Labreuche ◽

Maxime Bruto ◽

Hajar Amraoui ◽

Etienne Robino ◽

...

Keyword(s):

Vibrio Splendidus ◽

Trade Off ◽

O Antigen ◽

Antigen Structure

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Elucidation of the O-antigen structure of Escherichia coli O63

Glycobiology ◽

10.1093/glycob/cwy098 ◽

2018 ◽

Vol 29 (2) ◽

pp. 179-187 ◽

Cited By ~ 3

Author(s):

Jonas Ståhle ◽

Carolina Fontana ◽

Andrej Weintraub ◽

Göran Widmalm

Keyword(s):

Escherichia Coli ◽

Biosynthetic Pathway ◽

Sugar Residue ◽

Serine Residue ◽

Structural Element ◽

Multiple Gene ◽

E Coli ◽

O Antigen ◽

Antigen Structure

AbstractThe structure of the O-antigen polysaccharide (PS) from the Shiga-toxin producing Escherichia coli O63 has been elucidated using a combination of bioinformatics, component analyses and NMR spectroscopy. The O-antigen is comprised of tetrasaccharide repeating units with the following structure: →2)-β-d-Quip3N(d-allo-ThrAc)-(1→2)-β-d-Ribf-(1→4)-β-d-Galp-(1→3)-α-d-GlcpNAc-(1→ in which the N-acetylated d-allo-threonine is amide-linked to position 3 of the 3-amino-3-deoxy-d-Quip sugar residue. The presence of a predicted flippase and polymerase encoded in the O63 gene cluster is consistent with the Wzx/Wzy biosynthetic pathway and consequently the biological repeating unit has likely an N-acetyl-d-glucosamine residue at its reducing end. A bioinformatics approach based on predictive glycosyltransferase function present in ECODAB (E. coli O-antigen database) suggested the structural element β-d-Galp-(1→3)-d-GlcpNAc in the O-antigen. Notably, multiple gene sequence alignment of fdtA and qdtA from E. coli to that in E. coli O63 resulted in discrimination between the two, confirmation of the latter in E. coli O63, and consequently, together with qdtB, biosynthesis of dTDP-d-Quip3N. The E. coli O63 O-antigen polysaccharide differs in two aspects from that of E. coli O114 where the latter carries instead an l-serine residue, and the glycosidic linkage positions to and from the Quip3N residue are both changed. The structural characterization of the O63 antigen repeat supports the predicted functional assignment of the O-antigen cluster genes.

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