Hold the lemon, please. Next time you go to a restaurant and order water, tell the waiter no, when he asks if youd like lemon with that. Out of 76 samples from restaurants, a new study found 53 lemons were contaminated with all sorts of germs and bacteria. There were four organisms... Two of them were of fecal origin that could have been human, from dirty fingertips. Every single organism has the potential to cause infection.