V. cholerae is pathogenic only for humans
Cholera Vibrios are ingested in drink or food and in natural infections, the small dose is enough to cause an infection. After passing the acid barrier of the stomach the organisms begin to multiply in the alkaline environment of the small intestine.
It gets attached to the microvilli of the epithelial cells of the intestinal tract where it multiplies and produce a potent enterotoxin known as cholera toxin.
Cholera toxin is responsible for increased secretion of water and electrolytes in stools from the intestinal cells leading to dehydration, shock, acidosis and death.