In a single day, two 19 year old women and one 20 year old man sought treatment at a university health clinic, complaining of acute diarrhea, nausea and vomiting. No blood was found in their stools. One of the women was found to have a UTI. All three had eaten lunch at a nearby health food store the previous day. The man had a turkey sandwich with tomato, sprouts, pickles and sunflower seeds. One woman had a pocket sandwich with turkey,sprouts, and mandarin oranges; the other woman had the lunch special, described in the menu as a "delightful garden salad of fresh organic lettuces, sprouts, tomatoes, and cucumbers with zesty raspberry vinaigrette dressing". All had bottled water to drink. Which of the foods is the most likely source of the infections? What media would you use to culture and isolate enteric contaminants in the food? Which enteric bacteria could cause these symptoms? What would be the appearance of this organism on this media?