The presence of numerous genera of spoilage bacteria, yeasts and molds, and an occasional pathogen on fresh produce has been recognized for many years. Several outbreaks of human gastroenteritis have been linked to the consumption of contaminated fresh vegetables and, to a lesser extent, fruits. Salads containing raw vegetables have been identified as vehicles of traveler's diarrhea, an illness sometimes experienced by visitors to developing countries. Enterotoxigenic Escherichia coli is the most common cause of this illness. Enterohemorrhagic E. coli, specifically serotype O157:H7, has been implicated as the causative agent in an outbreak of gastroenteritis resulting from the consumption of cantaloupes. Outbreaks of salmonellosis in humans have been attributed to consumption of contaminated tomatoes, mustard cress, bean sprouts, cantaloupe, and watermelon. An onion-associated outbreak of Shigella flexneri gastroenteritis has recently been reported in the United States. Outbreaks of human listeriosis have...