"The common occurrence (96 per cent) of coliform and E. coli bacteria on the outside of the shoes indicates frequent contact with fecal material, which most likely originates from floors in public restrooms or contact with animal fecal material outdoors," said Dr Gerba.
The aim of the study was to verify the existence of bacteria, but also to determine its movement from shoe to floor.
"Our study also indicated that bacteria can be tracked by shoes over a long distance into your home or personal space after the shoes were contaminated with bacteria," Dr Gerba added.
Researchers had a volunteer walk over uncontaminated surfaces and recorded the bacteria. More than 90 percent of the time, bacteria transferred from the shoes to the surface.
The good news is, washing your shoes in the washing machine was found to reduce bacteria by 99 per cent.