Fecal contamination from the intestines of cattle and sheep during slaughter is one of the most prevalent pathways for infection. Similar outbreaks have been reported in Japan and the United Kingdom. However, a carcass that is not infected with E. coli from its own intestines may accidentally contact a contaminated carcass or come in contact with a contaminated surface. Researchers have found that some food preparation surfaces, such as copper and brass, have a bactericidal effect on E. coli O157 bacteria. Since infected carcasses in food preparation can contaminate work surfaces, the risk of cross contamination of non-infected carcasses can be reduced by using a surface that exhibits a bactericidal effect on the microbes.
Stainless steel is the most widely used surface material in food processing.
It is nontoxic and easy to clean. However, stainless steel scratches, harbors microbes if not disinfected frequently, and does not exhibit the bactericidal properties of copper and brass. This means that the surface itself can become a source of cross contamination. CAMR researchers also found that E. coli O157 dies off much more quickly on copper and brass surfaces than on stainless steel surfaces. Their preliminary study suggested that copper and brass are much more hygienic as a food preparation surface than stainless steel.