By testing a brand-new commercial cooking facility before and after processing began, the research team was able to track sources of contamination. The results of a 21-month study, published in the February 2010 issue of Journal of Food Protection, should help other plants focus their sanitation processes to reduce cross-contamination.
Because Lm is prevalent in the environment and in various forms, there were several potential sources of contamination, including employees, incoming fresh air, raw meat and the environment. By extensive testing, these other sources could be discounted as the main source of contamination. The only tested source found to be consistently positive for Lm was incoming raw poultry meat.