Carriage of stx2a differentiates clinical and bovine-biased strains of Escherichia coli O157.
Shiga toxin (Stx) are cardinal virulence factors of enterohemorrhagic E. coli O157:H7 (EHEC O157). The gene content and genomic insertion sites of Stx-associated bacteriophages differentiate clinical genotypes of EHEC O157 (CG, typical of clinical isolates) from bovine-biased genotypes (BBG, rarely...
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2012-01-01
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doaj-26bf35db415b4511a0fb7bfd9efca2602020-11-25T00:08:36ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-01712e5157210.1371/journal.pone.0051572Carriage of stx2a differentiates clinical and bovine-biased strains of Escherichia coli O157.Smriti ShringiCarrie SchmidtKaya KatherineKelly A BraytonDale D HancockThomas E BesserShiga toxin (Stx) are cardinal virulence factors of enterohemorrhagic E. coli O157:H7 (EHEC O157). The gene content and genomic insertion sites of Stx-associated bacteriophages differentiate clinical genotypes of EHEC O157 (CG, typical of clinical isolates) from bovine-biased genotypes (BBG, rarely identified among clinical isolates). This project was designed to identify bacteriophage-mediated differences that may affect the virulence of CG and BBG.Stx-associated bacteriophage differences were identified by whole genome optical scans and characterized among >400 EHEC O157 clinical and cattle isolates by PCR.Optical restriction maps of BBG strains consistently differed from those of CG strains only in the chromosomal insertion sites of Stx2-associated bacteriophages. Multiplex PCRs (stx1, stx2a, and stx2c as well as Stx-associated bacteriophage-chromosomal insertion site junctions) revealed four CG and three BBG that accounted for >90% of isolates. All BBG contained stx2c and Stx2c-associated bacteriophage-sbcB junctions. All CG contained stx2a and Stx2a-associated bacteriophage junctions in wrbA or argW.Presence or absence of stx2a (or another product encoded by the Stx2a-associated bacteriophage) is a parsimonious explanation for differential virulence of BBG and CG, as reflected in the distributions of these genotypes in humans and in the cattle reservoir.http://europepmc.org/articles/PMC3519850?pdf=render |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Smriti Shringi Carrie Schmidt Kaya Katherine Kelly A Brayton Dale D Hancock Thomas E Besser |
spellingShingle |
Smriti Shringi Carrie Schmidt Kaya Katherine Kelly A Brayton Dale D Hancock Thomas E Besser Carriage of stx2a differentiates clinical and bovine-biased strains of Escherichia coli O157. PLoS ONE |
author_facet |
Smriti Shringi Carrie Schmidt Kaya Katherine Kelly A Brayton Dale D Hancock Thomas E Besser |
author_sort |
Smriti Shringi |
title |
Carriage of stx2a differentiates clinical and bovine-biased strains of Escherichia coli O157. |
title_short |
Carriage of stx2a differentiates clinical and bovine-biased strains of Escherichia coli O157. |
title_full |
Carriage of stx2a differentiates clinical and bovine-biased strains of Escherichia coli O157. |
title_fullStr |
Carriage of stx2a differentiates clinical and bovine-biased strains of Escherichia coli O157. |
title_full_unstemmed |
Carriage of stx2a differentiates clinical and bovine-biased strains of Escherichia coli O157. |
title_sort |
carriage of stx2a differentiates clinical and bovine-biased strains of escherichia coli o157. |
publisher |
Public Library of Science (PLoS) |
series |
PLoS ONE |
issn |
1932-6203 |
publishDate |
2012-01-01 |
description |
Shiga toxin (Stx) are cardinal virulence factors of enterohemorrhagic E. coli O157:H7 (EHEC O157). The gene content and genomic insertion sites of Stx-associated bacteriophages differentiate clinical genotypes of EHEC O157 (CG, typical of clinical isolates) from bovine-biased genotypes (BBG, rarely identified among clinical isolates). This project was designed to identify bacteriophage-mediated differences that may affect the virulence of CG and BBG.Stx-associated bacteriophage differences were identified by whole genome optical scans and characterized among >400 EHEC O157 clinical and cattle isolates by PCR.Optical restriction maps of BBG strains consistently differed from those of CG strains only in the chromosomal insertion sites of Stx2-associated bacteriophages. Multiplex PCRs (stx1, stx2a, and stx2c as well as Stx-associated bacteriophage-chromosomal insertion site junctions) revealed four CG and three BBG that accounted for >90% of isolates. All BBG contained stx2c and Stx2c-associated bacteriophage-sbcB junctions. All CG contained stx2a and Stx2a-associated bacteriophage junctions in wrbA or argW.Presence or absence of stx2a (or another product encoded by the Stx2a-associated bacteriophage) is a parsimonious explanation for differential virulence of BBG and CG, as reflected in the distributions of these genotypes in humans and in the cattle reservoir. |
url |
http://europepmc.org/articles/PMC3519850?pdf=render |
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