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Chapter 26
Foodborne Bacterial infections
introduction
Foodborne infection occurs from the consumption of food (and water) contaminated with pathogenic enteric bacteria and viruses. Many pathogens are included in this group. Viruses are discussed in Chapter 28. However, many are involved more frequently than others, and they are
discussed in this chapter. The discussions include their relative importance, characteristics, food
association, toxins, disease symptoms, and prevention. For some, detection methods and case histories are also included. The following are some characteristics of foodborne infections:
1. Live cells of the enteric pathogens (bacteria and viruses) have to be consumed through food.
2. The surviving cells (from gastric environment) penetrate through the mucus membrane and
establish in the epithelial cells of the intestines, multiply, and produce toxins and other virulence factors.
3. Dose levels that cause infection vary greatly. Theoretically, one live cell has the potential to
produce the disease. Experts estimate that consumption of approximately 10 cells (for an
extremely virulent species and strain, such as Escherichia coli O157:H7) to approximately 10 5
cells or more (for a less virulent species and strain, such as Yersinia enterocolitica) might be
required for the disease.
4. Symptoms generally occur after 24 hours, which, depending on the pathogen, can be both
enteric and nonenteric in nature.
5. Enteric symptoms are local and result from enteric infection and the effect of toxins.
Symptoms include abdominal pain, diarrhea (sometimes accompanied with blood), nausea,
vomiting, and fever. Examples of pathogens include Salmonella, Shigella, enteropathogenic
Esc. coli (EPEC), Vibrio parahaemolyticus, Campylobacter jejuni, and Yer. enterocolitica.
6. Nonenteric symptoms (along with enteric symptoms) result when the pathogens or their
toxins pass through the intestine and invade or affect other internal organs and tissues.
Symptoms depend on the types of organs and tissues affected but are accompanied by fever.
Examples of pathogens include Listeria monocytogenes, enterohemorrhagic Esc. coli (EHEC),
Vib. vulnificus, and Hepatitis A virus.
Chapter 26
Foodborne Bacterial infections
introduction
Foodborne infection occurs from the consumption of food (and water) contaminated with pathogenic enteric bacteria and viruses. Many pathogens are included in this group. Viruses are discussed in Chapter 28. However, many are involved more frequently than others, and they are
discussed in this chapter. The discussions include their relative importance, characteristics, food
association, toxins, disease symptoms, and prevention. For some, detection methods and case histories are also included. The following are some characteristics of foodborne infections:
1. Live cells of the enteric pathogens (bacteria and viruses) have to be consumed through food.
2. The surviving cells (from gastric environment) penetrate through the mucus membrane and
establish in the epithelial cells of the intestines, multiply, and produce toxins and other virulence factors.
3. Dose levels that cause infection vary greatly. Theoretically, one live cell has the potential to
produce the disease. Experts estimate that consumption of approximately 10 cells (for an
extremely virulent species and strain, such as Escherichia coli O157:H7) to approximately 10 5
cells or more (for a less virulent species and strain, such as Yersinia enterocolitica) might be
required for the disease.
4. Symptoms generally occur after 24 hours, which, depending on the pathogen, can be both
enteric and nonenteric in nature.
5. Enteric symptoms are local and result from enteric infection and the effect of toxins.
Symptoms include abdominal pain, diarrhea (sometimes accompanied with blood), nausea,
vomiting, and fever. Examples of pathogens include Salmonella, Shigella, enteropathogenic
Esc. coli (EPEC), Vibrio parahaemolyticus, Campylobacter jejuni, and Yer. enterocolitica.
6. Nonenteric symptoms (along with enteric symptoms) result when the pathogens or their
toxins pass through the intestine and invade or affect other internal organs and tissues.
Symptoms depend on the types of organs and tissues affected but are accompanied by fever.
Examples of pathogens include Listeria monocytogenes, enterohemorrhagic Esc. coli (EHEC),
Vib. vulnificus, and Hepatitis A virus.