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Wide Distribution of O157-Antigen Biosynthesis Gene Clusters in Escherichia coli
Most Escherichia coli O157-serogroup strains are classified as enterohemorrhagic E. coli (EHEC), which is known as an important food-borne pathogen for humans. They usually produce Shiga toxin (Stx) 1 and/or Stx2, and express H7-flagella antigen (or nonmotile). However, O157 strains that do not prod...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Public Library of Science
2011
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3158064/ https://www.ncbi.nlm.nih.gov/pubmed/21876740 http://dx.doi.org/10.1371/journal.pone.0023250 |
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author | Iguchi, Atsushi Shirai, Hiroki Seto, Kazuko Ooka, Tadasuke Ogura, Yoshitoshi Hayashi, Tetsuya Osawa, Kayo Osawa, Ro |
author_facet | Iguchi, Atsushi Shirai, Hiroki Seto, Kazuko Ooka, Tadasuke Ogura, Yoshitoshi Hayashi, Tetsuya Osawa, Kayo Osawa, Ro |
author_sort | Iguchi, Atsushi |
collection | PubMed |
description | Most Escherichia coli O157-serogroup strains are classified as enterohemorrhagic E. coli (EHEC), which is known as an important food-borne pathogen for humans. They usually produce Shiga toxin (Stx) 1 and/or Stx2, and express H7-flagella antigen (or nonmotile). However, O157 strains that do not produce Stxs and express H antigens different from H7 are sometimes isolated from clinical and other sources. Multilocus sequence analysis revealed that these 21 O157:non-H7 strains tested in this study belong to multiple evolutionary lineages different from that of EHEC O157:H7 strains, suggesting a wide distribution of the gene set encoding the O157-antigen biosynthesis in multiple lineages. To gain insight into the gene organization and the sequence similarity of the O157-antigen biosynthesis gene clusters, we conducted genomic comparisons of the chromosomal regions (about 59 kb in each strain) covering the O-antigen gene cluster and its flanking regions between six O157:H7/non-H7 strains. Gene organization of the O157-antigen gene cluster was identical among O157:H7/non-H7 strains, but was divided into two distinct types at the nucleotide sequence level. Interestingly, distribution of the two types did not clearly follow the evolutionary lineages of the strains, suggesting that horizontal gene transfer of both types of O157-antigen gene clusters has occurred independently among E. coli strains. Additionally, detailed sequence comparison revealed that some positions of the repetitive extragenic palindromic (REP) sequences in the regions flanking the O-antigen gene clusters were coincident with possible recombination points. From these results, we conclude that the horizontal transfer of the O157-antigen gene clusters induced the emergence of multiple O157 lineages within E. coli and speculate that REP sequences may involve one of the driving forces for exchange and evolution of O-antigen loci. |
format | Online Article Text |
id | pubmed-3158064 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2011 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-31580642011-08-29 Wide Distribution of O157-Antigen Biosynthesis Gene Clusters in Escherichia coli Iguchi, Atsushi Shirai, Hiroki Seto, Kazuko Ooka, Tadasuke Ogura, Yoshitoshi Hayashi, Tetsuya Osawa, Kayo Osawa, Ro PLoS One Research Article Most Escherichia coli O157-serogroup strains are classified as enterohemorrhagic E. coli (EHEC), which is known as an important food-borne pathogen for humans. They usually produce Shiga toxin (Stx) 1 and/or Stx2, and express H7-flagella antigen (or nonmotile). However, O157 strains that do not produce Stxs and express H antigens different from H7 are sometimes isolated from clinical and other sources. Multilocus sequence analysis revealed that these 21 O157:non-H7 strains tested in this study belong to multiple evolutionary lineages different from that of EHEC O157:H7 strains, suggesting a wide distribution of the gene set encoding the O157-antigen biosynthesis in multiple lineages. To gain insight into the gene organization and the sequence similarity of the O157-antigen biosynthesis gene clusters, we conducted genomic comparisons of the chromosomal regions (about 59 kb in each strain) covering the O-antigen gene cluster and its flanking regions between six O157:H7/non-H7 strains. Gene organization of the O157-antigen gene cluster was identical among O157:H7/non-H7 strains, but was divided into two distinct types at the nucleotide sequence level. Interestingly, distribution of the two types did not clearly follow the evolutionary lineages of the strains, suggesting that horizontal gene transfer of both types of O157-antigen gene clusters has occurred independently among E. coli strains. Additionally, detailed sequence comparison revealed that some positions of the repetitive extragenic palindromic (REP) sequences in the regions flanking the O-antigen gene clusters were coincident with possible recombination points. From these results, we conclude that the horizontal transfer of the O157-antigen gene clusters induced the emergence of multiple O157 lineages within E. coli and speculate that REP sequences may involve one of the driving forces for exchange and evolution of O-antigen loci. Public Library of Science 2011-08-18 /pmc/articles/PMC3158064/ /pubmed/21876740 http://dx.doi.org/10.1371/journal.pone.0023250 Text en Iguchi et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Iguchi, Atsushi Shirai, Hiroki Seto, Kazuko Ooka, Tadasuke Ogura, Yoshitoshi Hayashi, Tetsuya Osawa, Kayo Osawa, Ro Wide Distribution of O157-Antigen Biosynthesis Gene Clusters in Escherichia coli |
title | Wide Distribution of O157-Antigen Biosynthesis Gene Clusters in Escherichia coli
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title_full | Wide Distribution of O157-Antigen Biosynthesis Gene Clusters in Escherichia coli
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title_fullStr | Wide Distribution of O157-Antigen Biosynthesis Gene Clusters in Escherichia coli
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title_full_unstemmed | Wide Distribution of O157-Antigen Biosynthesis Gene Clusters in Escherichia coli
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title_short | Wide Distribution of O157-Antigen Biosynthesis Gene Clusters in Escherichia coli
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title_sort | wide distribution of o157-antigen biosynthesis gene clusters in escherichia coli |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3158064/ https://www.ncbi.nlm.nih.gov/pubmed/21876740 http://dx.doi.org/10.1371/journal.pone.0023250 |
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