Hazard Identification and Characterization: Criteria for Categorizing Shiga Toxin-Producing Escherichia coli on a Risk Basis

FAO WHO Stec Expert Grp

Research output: Contribution to journalJournal articleResearchpeer-review

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Abstract

Shiga toxin-producing Escherichia coli (STEC) comprise a large, highly diverse group of strains. Since the emergence of STEC serotype O157:H7 as an important foodborne pathogen, serotype data have been used for identifying STEC strains, and this use continued as other serotypes were implicated in human infections. An estimated 470 STEC serotypes have been identified, which can produce one or more of the 12 known Shiga toxin (Stx) subtypes. The number of STEC serotypes that cause human illness varies but is probably higher than 100. However, many STEC virulence genes are mobile and can be lost or transferred to other bacteria; therefore, STEC strains that have the same serotype may not carry the same virulence genes or pose the same risk. Although serotype information is useful in outbreak investigations and surveillance studies, it is not a reliable means of assessing the human health risk posed by a particular STEC serotype. To contribute to the development of a set of criteria that would more reliably support hazard identification, this review considered each of the factors contributing to a negative human health outcome: mild diarrhea, bloody diarrhea, and hemolytic uremic syndrome (HUS). STEC pathogenesis involves entry into the human gut (often via ingestion), attachment to the intestinal epithelial cells, and elaboration of Stx. Production of Stx, which disrupts normal cellular functions and causes cell damage, alone without adherence of bacterial cells to gut epithelial cells is insufficient to cause severe illness. The principal adherence factor in STEC is the intimin protein coded by the eae gene. The aggregative adherence fimbriae adhesins regulated by the aggR gene of enteroaggregative E. coli strains are also effective adherence factors. The stx(2a) gene is most often present in locus of enterocyte effacement (eae)-positive STEC strains and has consistently been associated with HUS. The stx(2a) gene has also been found in eae-negative, aggR-positive STEC that have caused HUS. HUS cases where other stx gene subtypes were identified indicate that other factors such as host susceptibility and the genetic cocktail of virulence genes in individual isolates may affect their association with severe diseases.

Original languageEnglish
JournalJournal of Food Protection
Volume82
Issue number1
Pages (from-to)7-21
ISSN0362-028X
DOIs
Publication statusPublished - 2019

Keywords

  • Characterization
  • Risk criteria
  • Shiga toxin-producing Escherichia coli

Cite this

@article{04edd11fb1a041f5a2c630c88a072ad1,
title = "Hazard Identification and Characterization: Criteria for Categorizing Shiga Toxin-Producing Escherichia coli on a Risk Basis",
abstract = "Shiga toxin-producing Escherichia coli (STEC) comprise a large, highly diverse group of strains. Since the emergence of STEC serotype O157:H7 as an important foodborne pathogen, serotype data have been used for identifying STEC strains, and this use continued as other serotypes were implicated in human infections. An estimated 470 STEC serotypes have been identified, which can produce one or more of the 12 known Shiga toxin (Stx) subtypes. The number of STEC serotypes that cause human illness varies but is probably higher than 100. However, many STEC virulence genes are mobile and can be lost or transferred to other bacteria; therefore, STEC strains that have the same serotype may not carry the same virulence genes or pose the same risk. Although serotype information is useful in outbreak investigations and surveillance studies, it is not a reliable means of assessing the human health risk posed by a particular STEC serotype. To contribute to the development of a set of criteria that would more reliably support hazard identification, this review considered each of the factors contributing to a negative human health outcome: mild diarrhea, bloody diarrhea, and hemolytic uremic syndrome (HUS). STEC pathogenesis involves entry into the human gut (often via ingestion), attachment to the intestinal epithelial cells, and elaboration of Stx. Production of Stx, which disrupts normal cellular functions and causes cell damage, alone without adherence of bacterial cells to gut epithelial cells is insufficient to cause severe illness. The principal adherence factor in STEC is the intimin protein coded by the eae gene. The aggregative adherence fimbriae adhesins regulated by the aggR gene of enteroaggregative E. coli strains are also effective adherence factors. The stx(2a) gene is most often present in locus of enterocyte effacement (eae)-positive STEC strains and has consistently been associated with HUS. The stx(2a) gene has also been found in eae-negative, aggR-positive STEC that have caused HUS. HUS cases where other stx gene subtypes were identified indicate that other factors such as host susceptibility and the genetic cocktail of virulence genes in individual isolates may affect their association with severe diseases.",
keywords = "Characterization, Risk criteria, Shiga toxin-producing Escherichia coli",
author = "{FAO WHO Stec Expert Grp} and Hiroshi Asakura and Nadia Boisen and Isabel Chinen and Roger Cook and Tim Dallman and Brecht Devleesschauwer and Peter Feng and Eelco Franz and Pina Fratamico and Alex Gill and Patricia Griffin and Karen Keddy and Geoffrey Mainda and Shannon Majowicz and Pires, {Sara Monteiro} and Yemi Ogunrinola and Flemming Scheutz and Potjanee Srimanote and Alvarez, {Roberto Vidal} and Emilio Esteban and Jeffrey LeJeune and Gillian Mylrea and Diego Moreira and Shaw, {William K.} and Sarah Cahill and Blaise Ouattara and Patricia Desmarchelier and Rei Nakagawa and Kang Zhou",
year = "2019",
doi = "10.4315/0362-028X.JFP-18-291",
language = "English",
volume = "82",
pages = "7--21",
journal = "Journal of Food Protection",
issn = "0362-028X",
publisher = "INT ASSOC FOOD PROTECTION",
number = "1",

}

Hazard Identification and Characterization: Criteria for Categorizing Shiga Toxin-Producing Escherichia coli on a Risk Basis. / FAO WHO Stec Expert Grp.

In: Journal of Food Protection, Vol. 82, No. 1, 2019, p. 7-21.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Hazard Identification and Characterization: Criteria for Categorizing Shiga Toxin-Producing Escherichia coli on a Risk Basis

AU - FAO WHO Stec Expert Grp

AU - Asakura, Hiroshi

AU - Boisen, Nadia

AU - Chinen, Isabel

AU - Cook, Roger

AU - Dallman, Tim

AU - Devleesschauwer, Brecht

AU - Feng, Peter

AU - Franz, Eelco

AU - Fratamico, Pina

AU - Gill, Alex

AU - Griffin, Patricia

AU - Keddy, Karen

AU - Mainda, Geoffrey

AU - Majowicz, Shannon

AU - Pires, Sara Monteiro

AU - Ogunrinola, Yemi

AU - Scheutz, Flemming

AU - Srimanote, Potjanee

AU - Alvarez, Roberto Vidal

AU - Esteban, Emilio

AU - LeJeune, Jeffrey

AU - Mylrea, Gillian

AU - Moreira, Diego

AU - Shaw, William K.

AU - Cahill, Sarah

AU - Ouattara, Blaise

AU - Desmarchelier, Patricia

AU - Nakagawa, Rei

AU - Zhou, Kang

PY - 2019

Y1 - 2019

N2 - Shiga toxin-producing Escherichia coli (STEC) comprise a large, highly diverse group of strains. Since the emergence of STEC serotype O157:H7 as an important foodborne pathogen, serotype data have been used for identifying STEC strains, and this use continued as other serotypes were implicated in human infections. An estimated 470 STEC serotypes have been identified, which can produce one or more of the 12 known Shiga toxin (Stx) subtypes. The number of STEC serotypes that cause human illness varies but is probably higher than 100. However, many STEC virulence genes are mobile and can be lost or transferred to other bacteria; therefore, STEC strains that have the same serotype may not carry the same virulence genes or pose the same risk. Although serotype information is useful in outbreak investigations and surveillance studies, it is not a reliable means of assessing the human health risk posed by a particular STEC serotype. To contribute to the development of a set of criteria that would more reliably support hazard identification, this review considered each of the factors contributing to a negative human health outcome: mild diarrhea, bloody diarrhea, and hemolytic uremic syndrome (HUS). STEC pathogenesis involves entry into the human gut (often via ingestion), attachment to the intestinal epithelial cells, and elaboration of Stx. Production of Stx, which disrupts normal cellular functions and causes cell damage, alone without adherence of bacterial cells to gut epithelial cells is insufficient to cause severe illness. The principal adherence factor in STEC is the intimin protein coded by the eae gene. The aggregative adherence fimbriae adhesins regulated by the aggR gene of enteroaggregative E. coli strains are also effective adherence factors. The stx(2a) gene is most often present in locus of enterocyte effacement (eae)-positive STEC strains and has consistently been associated with HUS. The stx(2a) gene has also been found in eae-negative, aggR-positive STEC that have caused HUS. HUS cases where other stx gene subtypes were identified indicate that other factors such as host susceptibility and the genetic cocktail of virulence genes in individual isolates may affect their association with severe diseases.

AB - Shiga toxin-producing Escherichia coli (STEC) comprise a large, highly diverse group of strains. Since the emergence of STEC serotype O157:H7 as an important foodborne pathogen, serotype data have been used for identifying STEC strains, and this use continued as other serotypes were implicated in human infections. An estimated 470 STEC serotypes have been identified, which can produce one or more of the 12 known Shiga toxin (Stx) subtypes. The number of STEC serotypes that cause human illness varies but is probably higher than 100. However, many STEC virulence genes are mobile and can be lost or transferred to other bacteria; therefore, STEC strains that have the same serotype may not carry the same virulence genes or pose the same risk. Although serotype information is useful in outbreak investigations and surveillance studies, it is not a reliable means of assessing the human health risk posed by a particular STEC serotype. To contribute to the development of a set of criteria that would more reliably support hazard identification, this review considered each of the factors contributing to a negative human health outcome: mild diarrhea, bloody diarrhea, and hemolytic uremic syndrome (HUS). STEC pathogenesis involves entry into the human gut (often via ingestion), attachment to the intestinal epithelial cells, and elaboration of Stx. Production of Stx, which disrupts normal cellular functions and causes cell damage, alone without adherence of bacterial cells to gut epithelial cells is insufficient to cause severe illness. The principal adherence factor in STEC is the intimin protein coded by the eae gene. The aggregative adherence fimbriae adhesins regulated by the aggR gene of enteroaggregative E. coli strains are also effective adherence factors. The stx(2a) gene is most often present in locus of enterocyte effacement (eae)-positive STEC strains and has consistently been associated with HUS. The stx(2a) gene has also been found in eae-negative, aggR-positive STEC that have caused HUS. HUS cases where other stx gene subtypes were identified indicate that other factors such as host susceptibility and the genetic cocktail of virulence genes in individual isolates may affect their association with severe diseases.

KW - Characterization

KW - Risk criteria

KW - Shiga toxin-producing Escherichia coli

U2 - 10.4315/0362-028X.JFP-18-291

DO - 10.4315/0362-028X.JFP-18-291

M3 - Journal article

VL - 82

SP - 7

EP - 21

JO - Journal of Food Protection

JF - Journal of Food Protection

SN - 0362-028X

IS - 1

ER -