I work at a food production plant. Our main function is dry blending of powdered flavor components. We have been facing a re-occurring Listeria problem in one of our blending rooms. We have had two hits on the floor and one in the drain. The first two investigations we deduced that it was due to the ineffective cleaning by a poorly trained operator. We re-trained him and are still experiencing issues. I am trying to conduct a root cause analysis to see if there are any other factors contributing to our Listeria problem.
What are everyone's experiences with Listeria and what are some sources you have seen and also corrective actions to prevent another hit from occurring.
Any help is greatly appreciated