BACTERIAL TOXICOGENIC DIARRHEAS

Bacterial Toxigenic Diarrheas:  Excessive volume, life threatening intestinal electrolyte and fluid secretion also known as diarrhea, occurs in patients with cholera, an intestinal infection by Vibrio cholerae. Certain strains of E. coli are also capable of causing a condition known as "Traveler's diarrhea". 

Pathophysiology:  The secretory state is a result of enterotoxins produced by the bacteria. The mechanisms of action of some of these enterotoxins are well understood at the biochemical level. Cholera toxin activates adenylyl cyclase by causing ADPribosylation of the Gas protein, which stimulates the cyclase. Elevated cAMP levels in turn activate protein kinase A, which opens the luminal CFTR Cl– channel and inhibits the Na+/H+ exchanger by protein phosphorylation. The net result is gross NaCl secretion.  And because where sodium goes, water follow by passive diffusion, this leads to in-flow of excess water from the intestinal tissues to the lumen.

Treatment and management:  Modern, oral treatment of cholera takes advantage of the presence of Na+/glucose cotransport in the intestine, which is not regulated by cAMP and remains fully active in this disease. In this case, the presence of glucose allows uptake of Na+ to replenish body NaCl. Composition of solution for oral treatment of cholera patients is glucose 110 mM, Na+ 99 mM, Cl– 74 mM, HCO3– 29 mM, and K+ 4 mM. The major advantages of this form of therapy are its low cost and ease of administration when compared with intravenous fluid therapy.

RELATED;

1.  DIARRHEA

2.  CONSTIPATION

3.  PATHOGENICITY OF MICROORGANISMS 

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