1 Scope
This standard specifies the examination method of diarrheagenic Escherichia coli in foods.
This standard applies to the examination of diarrheagenic Escherichia coli in foods.
2 Terms, Definitions and Abbreviations
2.1 Terms and definitions
For the purpose of this standard, the following terms and definitions apply.
2.1.1 Diarrheagenic Escherichia coli
A kind of Escherichia coli can cause diarrhea-based symptom in human body via contaminated food. The common diarrheagenic Escherichia coli mainly includes enteropathogenic Escherichia coli, enteroinvasive Escherichia coli, enterotoxigenic Escherichia coli, Shiga toxin-producing Escherichia coli (including enterohemorrhagic Escherichia coli) and enteroaggregative Escherichia coli.
2.1.2 Enteropathogenic Escherichia coli
The Escherichia coli that can cause adhesion and wiping damage of host intestinal mucosa epithelial cell and does not produce Shiga toxin. This bacterium is the main pathogenic bacteria causing infant diarrhea, with high infectivity, which can be fatal in severe cases.
2.1.3 Enteroinvasive Escherichia coli
The Escherichia coli that can invade intestinal epithelial cell to cause dysentery-like diarrhea. This bacterium is free from power, lysine decarboxylic reaction and lactose fermentation, while with both biochemical reaction and antigenic structure approximate to that of Shigella dysenteriae. The key genes intruding epithelial cell are antigen encoding gene and controlling gene of invasive plasmid, such as ipaH-gene and ipaR-gene (also referred to as invE-gene).
2.1.4 Enterotoxigenic Escherichia coli
The Escherichia coli that can secrete heat-stable enterotoxin or/and heat-labile enterotoxin. This bacterium may cause infant and tourist diarrhea, which shows mild water-like diarrhea generally, and may shows serious cholera-like symptom, with low fever or no fever. Diarrhea is often self-limiting and can be self-healing in 2d~3d generally.
2.1.5 Shiga toxin-producing Escherichia coli (Enterohemorrhagic Escherichia coli)
The Escherichia coli that can secrete Shiga toxin and cause adhesion and wiping damage of host intestinal mucosa epithelial cell. Some Shiga toxin-producing Escherichia coli can cause clinically hemorrhagic colitis (HC) and bloody diarrhea in human, and may be further developed to become hemolytic uremic syndrome (HUS), this kind of Shiga toxin-producing Escherichia coli refers to enterohemorrhagic Escherichia coli.
Foreword I
1 Scope
2 Terms, Definitions and Abbreviations
3 Apparatus and Materials
4 Media and Reagents
5 Examination Produces
6 Operation Steps
7 Result Report
Appendix A Media and Reagents
1 Scope
This standard specifies the examination method of diarrheagenic Escherichia coli in foods.
This standard applies to the examination of diarrheagenic Escherichia coli in foods.
2 Terms, Definitions and Abbreviations
2.1 Terms and definitions
For the purpose of this standard, the following terms and definitions apply.
2.1.1 Diarrheagenic Escherichia coli
A kind of Escherichia coli can cause diarrhea-based symptom in human body via contaminated food. The common diarrheagenic Escherichia coli mainly includes enteropathogenic Escherichia coli, enteroinvasive Escherichia coli, enterotoxigenic Escherichia coli, Shiga toxin-producing Escherichia coli (including enterohemorrhagic Escherichia coli) and enteroaggregative Escherichia coli.
2.1.2 Enteropathogenic Escherichia coli
The Escherichia coli that can cause adhesion and wiping damage of host intestinal mucosa epithelial cell and does not produce Shiga toxin. This bacterium is the main pathogenic bacteria causing infant diarrhea, with high infectivity, which can be fatal in severe cases.
2.1.3 Enteroinvasive Escherichia coli
The Escherichia coli that can invade intestinal epithelial cell to cause dysentery-like diarrhea. This bacterium is free from power, lysine decarboxylic reaction and lactose fermentation, while with both biochemical reaction and antigenic structure approximate to that of Shigella dysenteriae. The key genes intruding epithelial cell are antigen encoding gene and controlling gene of invasive plasmid, such as ipaH-gene and ipaR-gene (also referred to as invE-gene).
2.1.4 Enterotoxigenic Escherichia coli
The Escherichia coli that can secrete heat-stable enterotoxin or/and heat-labile enterotoxin. This bacterium may cause infant and tourist diarrhea, which shows mild water-like diarrhea generally, and may shows serious cholera-like symptom, with low fever or no fever. Diarrhea is often self-limiting and can be self-healing in 2d~3d generally.
2.1.5 Shiga toxin-producing Escherichia coli (Enterohemorrhagic Escherichia coli)
The Escherichia coli that can secrete Shiga toxin and cause adhesion and wiping damage of host intestinal mucosa epithelial cell. Some Shiga toxin-producing Escherichia coli can cause clinically hemorrhagic colitis (HC) and bloody diarrhea in human, and may be further developed to become hemolytic uremic syndrome (HUS), this kind of Shiga toxin-producing Escherichia coli refers to enterohemorrhagic Escherichia coli.
Contents of GB 4789.6-2016
Foreword I
1 Scope
2 Terms, Definitions and Abbreviations
3 Apparatus and Materials
4 Media and Reagents
5 Examination Produces
6 Operation Steps
7 Result Report
Appendix A Media and Reagents