The studies agree on several points. When food comes into contact with a contaminated surface, the transfer of bacteria to the food is immediate. And tile, wood, and laminate surfaces transfer much more bacteria than carpeted surfaces.

How long does it take for bacteria to transfer?

Bacteria can begin to transfer to food dropped on the floor in less than one second, according to research from New Brunswick, N.J.-based Rutgers University, effectively disproving the so-called "five-second rule."

How fast does bacteria spread on a surface?

Why it matters: Bacteria are among the fastest reproducing organisms in the world, doubling every 4 to 20 minutes.