This is my article that I had to research about with my group.

In the study, the researchers contaminated four different surfaces - stainless steel,ceramic tile, wood and carpet - with bacteria. Then the investigators dropped food on the surfaces, and allowed the food to sit for a certain amount of time: less than a second, 5 seconds, 30 seconds or 5 minutes. The scientists tested four food types: watermelon, bread, bread and butter and gummy candy.