Cholera is typically transmitted by either contaminated food or water. In the developed world, seafood is the usual cause, while in the developing world it is more often water. Cholera is rarely spread directly from person to person. Both toxic and nontoxic strains exist.
Most V. cholerae bacteria, when consumed, do not survive the acidic conditions of the human stomach. The few surviving bacteria conserve their energy and stored nutrients during the passage through the stomach by shutting down much protein production. When the surviving bacteria exit the stomach and reach the small intestine, they need to propel themselves through the thick mucus that lines the small intestine to get to the intestinal walls, where they can thrive. V. cholerae bacteria begin production of the hollow cylindrical protein flagellin to make flagella. These flagella are cork-screw helical fibers that rotate to propel the bacteria through the mucus of the small intestine.
Source: Boundless. “Cholera.” Boundless Microbiology. Boundless, 21 Jul. 2015. Retrieved 14 Dec. 2015 from https://www.boundless.com/microbiology/textbooks/boundless-microbiology-textbook/diseases-15/bacterial-diseases-of-the-digestive-system-183/cholera-914-3477/