VIBRIO PARAHAEMOLYTICUS. VIBRIO PARAHAEMOLYTICUS This scanning electron micrograph (SEM) depicts a number of Vibrio parahaemolyticus bacteria, Mag. 19058x. Vibrio parahaemolyticus is a bacterium in the same family as those that cause cholera. It lives in brackish saltwater, and causes gastrointestinal illness in humans. V. parahaemolyticus is a halophilic, or salt-requiring organism, naturally inhabiting coastal waters in the United States and Canada, and is present in higher concentrations