How long will sliced tomatoes stay fresh outside the refrigerator?

Tomatoes ,once sliced,should be eaten immediately .When left exposed they absorb bacteria from the surrounding air ,which when ingested, can cause food poisoning.This also applies to apples ,oranges ,onions among others. far as i have noticed day i was cutting slices of vegetables ..........after that i went out for some time aprox 5 hours...when i came back the slices of tomato just started i would say that a slicd tomato can only stay fresh for 5 hours outside the fridge!!!