لخّصلي

Foodborne invasive infection stems from consuming food or water with viable pathogens; their growth in the food isn't always required. Live pathogen cells must survive stomach acid, enter the intestines, adhere to epithelial cells, penetrate the membrane, multiply, and produce toxins. This leads to symptoms after an incubation period. Enteric symptoms (abdominal pain, diarrhea, nausea, vomiting, fever) are caused by pathogens like Salmonella and Shigella, while nonenteric symptoms (often including fever) arise from pathogens invading deeper tissues, exemplified by Listeria and enterohemorrhagic E. coli. The chapter focuses on important bacterial invasive infections, classifying them by causative bacteria, disease significance, pathogen characteristics, food sources, toxin type, symptoms, and prevention strategies.

Foodborne invasive infection is caused by ingestion of food and water containing viable pathogens. Growth of microorganisms in food may not be necessary. Since a large number of pathogens can cause contamination, it is necessary for them to remain alive in the food or water during consumption. Viable cells have the potential to penetrate into epithelial cells of the gastrointestinal tract and multiply (invasive). Multiplied cells produce toxins. The following are characteristics of foodborne invasive infection:

1 Live cells of pathogens must be consumed together with food.

2 Pathogens survive in stomach against acidity and their cells pass into intestine.

3 Pathogens colonize on the intestinal epithelial cells by adhesion.

4 The pathogens penetrate through the intestinal membrane, multiply in the epithelial cells, and produce toxin(s).

5 Enteric and nonenteric symptoms generally occur after duration period.

6 Enteric symptoms are abdominal pain, diarrhea, nausea, vomiting, and fever. Enteric pathogens are Salmonella, Shigella, enteroinvasive E. coli, V. parahaemo- lyticus, C. jejuni, and Y. enterocolitica.

7 Nonenteric symptoms result from the passage of pathogens to intestine, which invade epithelial cells or pass to internal organs, such as Listeria monocytogenes, enterohemorrhagic E. coli, V. vulnificus (vibriosis), viruses, Rickettsia, and proto- zoa. Symptoms depend on the type of affected organs and tissues but mainly include fever.

Some of the important bacterial foodborne invasive infections are included in this chapter based on types of bacteria causing infection, the relative importance of a disease, characteristics of the microorganism(s), predominant types of food, nature of toxin(s), symptoms, and prevention.