13
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Comparison of O-Antigen Gene Clusters of All O-Serogroups of Escherichia coli and Proposal for Adopting a New Nomenclature for O-Typing

      research-article

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Escherichia coli strains are classified based on O-antigens that are components of the lipopolysaccharide (LPS) in the cell envelope. O-antigens are important virulence factors, targets of both the innate and adaptive immune system, and play a role in host-pathogen interactions. Because they are highly immunogenic and display antigenic specificity unique for each strain, O-antigens are the biomarkers for designating O-types. Immunologically, 185 O-serogroups and 11 OX-groups exist for classification. Conventional serotyping for O-typing entails agglutination reactions between the O-antigen and antisera generated against each O-group. The procedure is labor intensive, not always accurate, and exhibits equivocal results. In this report, we present the sequences of 71 O-antigen gene clusters (O-AGC) and a comparison of all 196 O- and OX-groups. Many of the designated O-types, applied for classification over several decades, exhibited similar nucleotide sequences of the O-AGCs and cross-reacted serologically. Some O-AGCs carried insertion sequences and others had only a few nucleotide differences between them. Thus, based on these findings, it is proposed that several of the E. coli O-groups may be merged. Knowledge of the O-AGC sequences facilitates the development of molecular diagnostic platforms that are rapid, accurate, and reliable that can replace conventional serotyping. Additionally, with the scientific knowledge presented, new frontiers in the discovery of biomarkers, understanding the roles of O-antigens in the innate and adaptive immune system and pathogenesis, the development of glycoconjugate vaccines, and other investigations, can be explored.

          Related collections

          Most cited references36

          • Record: found
          • Abstract: found
          • Article: not found

          Biosynthesis of O-antigens: genes and pathways involved in nucleotide sugar precursor synthesis and O-antigen assembly.

          The O-antigen is an important component of the outer membrane of Gram-negative bacteria. It is a repeat unit polysaccharide and consists of a number of repeats of an oligosaccharide, the O-unit, which generally has between two and six sugar residues. O-Antigens are extremely variable, the variation lying in the nature, order and linkage of the different sugars within the polysaccharide. The genes involved in O-antigen biosynthesis are generally found on the chromosome as an O-antigen gene cluster, and the structural variation of O-antigens is mirrored by genetic variation seen in these clusters. The genes within the cluster fall into three major groups. The first group is involved in nucleotide sugar biosynthesis. These genes are often found together in the cluster and have a high level of identity. The genes coding for a significant number of nucleotide sugar biosynthesis pathways have been identified and these pathways seem to be conserved in different O-antigen clusters and across a wide range of species. The second group, the glycosyl transferases, is involved in sugar transfer. They are often dispersed throughout the cluster and have low levels of similarity. The third group is the O-antigen processing genes. This review is a summary of the current knowledge on these three groups of genes that comprise the O-antigen gene clusters, focusing on the most extensively studied E. coli and S. enterica gene clusters.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Structure and genetics of Shigella O antigens.

            This review covers the O antigens of the 46 serotypes of Shigella, but those of most Shigella flexneri are variants of one basic structure, leaving 34 Shigella distinct O antigens to review, together with their gene clusters. Several of the structures and gene clusters are reported for the first time and this is the first such group for which structures and DNA sequences have been determined for all O antigens. Shigella strains are in effect Escherichia coli with a specific mode of pathogenicity, and 18 of the 34 O antigens are also found in traditional E. coli. Three are very similar to E. coli O antigens and 13 are unique to Shigella strains. The O antigen of Shigella sonnei is quite atypical for E. coli and is thought to have transferred from Plesiomonas. The other 12 O antigens unique to Shigella strains have structures that are typical of E. coli, but there are considerably more anomalies in their gene clusters, probably reflecting recent modification of the structures. Having the complete set of structures and genes opens the way for experimental studies on the role of this diversity in pathogenicity.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              The structures of Escherichia coli O-polysaccharide antigens.

              Escherichia coli is usually a non-pathogenic member of the human colonic flora. However, certain strains have acquired virulence factors and may cause a variety of infections in humans and in animals. There are three clinical syndromes caused by E. coli: (i) sepsis/meningitis; (ii) urinary tract infection and (iii) diarrhoea. Furthermore the E. coli causing diarrhoea is divided into different 'pathotypes' depending on the type of disease, i.e. (i) enterotoxigenic; (ii) enteropathogenic; (iii) enteroinvasive; (iv) enterohaemorrhagic; (v) enteroaggregative and (vi) diffusely adherent. The serotyping of E. coli based on the somatic (O), flagellar (H) and capsular polysaccharide antigens (K) is used in epidemiology. The different antigens may be unique for a particular serogroup or antigenic determinants may be shared, resulting in cross-reactions with other serogroups of E. coli or even with other members of the family Enterobacteriacea. To establish the uniqueness of a particular serogroup or to identify the presence of common epitopes, a database of the structures of O-antigenic polysaccharides has been created. The E. coli database (ECODAB) contains structures, nuclear magnetic resonance chemical shifts and to some extent cross-reactivity relationships. All fields are searchable. A ranking is produced based on similarity, which facilitates rapid identification of strains that are difficult to serotype (if known) based on classical agglutinating methods. In addition, results pertinent to the biosynthesis of the repeating units of O-antigens are discussed. The ECODAB is accessible to the scientific community at http://www.casper.organ.su.se/ECODAB/.
                Bookmark

                Author and article information

                Contributors
                Role: Editor
                Journal
                PLoS One
                PLoS ONE
                plos
                plosone
                PLoS ONE
                Public Library of Science (San Francisco, CA USA )
                1932-6203
                29 January 2016
                2016
                : 11
                : 1
                : e0147434
                Affiliations
                [1 ]E, . coli, Reference Center, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
                [2 ]Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, Pennsylvania, United States of America
                [3 ]Animal Health & Food Safety, Life Sciences Solutions, Thermo Fisher Scientific, Austin, Texas, United States of America
                University of Nottingham, UNITED KINGDOM
                Author notes

                Competing Interests: Robert Tebbs, Catherine D. O’Connell, Michelle Swimley and Adam Allred were employees of Thermo Fisher Scientific when this study was performed. All other authors declare they have no competing interests.

                Conceived and designed the experiments: CD PMF XY GMB YL DSN. Performed the experiments: XY GMB YL ELR. Analyzed the data: CD PMF XY GMB YL DSN MM VK JARG ELR RK. Contributed reagents/materials/analysis tools: RT CDO AA MS JARG MM. Wrote the paper: CD PMF YL DSN XY GMB JARG RK.

                Article
                PONE-D-15-32044
                10.1371/journal.pone.0147434
                4732683
                26824864
                0a1a526a-5691-42f0-9780-a402a678e09f

                This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

                History
                : 21 July 2015
                : 3 January 2016
                Page count
                Figures: 3, Tables: 2, Pages: 13
                Funding
                Thermo Fisher Scientific partially supported sequencing of the O- antigen gene clusters and purchased some of the reference standard strains. Robert Tebbs and Michelle Swimley contributed on a technical level through generating whole genome sequencing results for some of the strains. Adam Aldred was involved in genome assembly.
                Categories
                Research Article
                Biology and Life Sciences
                Molecular Biology
                Molecular Biology Techniques
                Sequencing Techniques
                Nucleotide Sequencing
                Research and Analysis Methods
                Molecular Biology Techniques
                Sequencing Techniques
                Nucleotide Sequencing
                Medicine and Health Sciences
                Pathology and Laboratory Medicine
                Serology
                Biology and Life Sciences
                Anatomy
                Body Fluids
                Blood
                Blood Serum
                Immune Serum
                Medicine and Health Sciences
                Anatomy
                Body Fluids
                Blood
                Blood Serum
                Immune Serum
                Biology and Life Sciences
                Physiology
                Body Fluids
                Blood
                Blood Serum
                Immune Serum
                Medicine and Health Sciences
                Physiology
                Body Fluids
                Blood
                Blood Serum
                Immune Serum
                Medicine and Health Sciences
                Hematology
                Blood
                Blood Serum
                Immune Serum
                Biology and Life Sciences
                Biochemistry
                Biosynthesis
                Biology and Life Sciences
                Molecular Biology
                Molecular Biology Techniques
                Molecular Biology Assays and Analysis Techniques
                Phylogenetic Analysis
                Research and Analysis Methods
                Molecular Biology Techniques
                Molecular Biology Assays and Analysis Techniques
                Phylogenetic Analysis
                Biology and Life Sciences
                Biochemistry
                Enzymology
                Enzymes
                Transferases
                Biology and Life Sciences
                Biochemistry
                Proteins
                Enzymes
                Transferases
                Biology and life sciences
                Molecular biology
                Molecular biology techniques
                DNA construction
                DNA library construction
                Genomic Library Construction
                Research and analysis methods
                Molecular biology techniques
                DNA construction
                DNA library construction
                Genomic Library Construction
                Research and Analysis Methods
                Database and Informatics Methods
                Biological Databases
                Sequence Databases
                Biology and Life Sciences
                Molecular Biology
                Molecular Biology Techniques
                Sequencing Techniques
                Sequence Analysis
                Sequence Databases
                Research and Analysis Methods
                Molecular Biology Techniques
                Sequencing Techniques
                Sequence Analysis
                Sequence Databases
                Custom metadata
                GenBank Accessions are provided in S1 Table.

                Uncategorized
                Uncategorized

                Comments

                Comment on this article