Pathogenesis of diarrhea in food poisoning

Non- inflammatory diarrhea

• The action of enterotoxins on the secretory mechanisms of the mucosa of the small intestine (no invasion).

• Large volume watery stools (no blood, pus, or severe abdominal pain).Dehydration.

• -The enterotoxins may be either preformed before ingestion or produced in the gut after ingestion.

Examples -Vibrio cholerae, enterotoxic Escherichia coli, Clostridium perfringens, Bacillus cereus, Staphylococcus organisms , Giardia lamblia, Cryptosporidium,rotavirus, norovirus (genus Norovirus, previously called Norwalk virus), and adenovirus.

Inflammatory diarrhea• the action of cytotoxin on the mucosa, leading to invasion and

destruction. The colon or the distal small bowel commonly is involved.

• bloody stool ; mucoid and leukocytes are present. Fever or toxic smaller stool volumes.

• Fecal leukocytes test or a positive stool lactoferrin test• Sometimes, the organisms penetrate the mucosa and proliferate

in the local lymphatic tissue, followed by systemic dissemination.

Examples- Campylobacter jejuni, Vibrio parahaemolyticus, enterohemorrhagic and enteroinvasive E coli, Yersinia enterocolitica, Clostridium difficile, Entamoeba histolytica, and Salmonella and Shigella species.

• In some types of food poisoning (eg, staphylococci, B cereus), vomiting is caused by a toxin acting on the central nervous system.

• The clinical syndrome of botulism results from the inhibition of acetylcholine release in nerve endings by the botulinum.

• some of the noninfectious causes of food poisoning (naturally occurring substances [eg, mushrooms, toadstools] and heavy metals [eg, arsenic, mercury, lead] acute GIsymptoms