Hi,
I am familiar with low risk products that has had rare L. mono environmental detection but have recently come into contact with a high care facility that would have fairly frequent Listeria mono. contamination in high care drains ranging from one positive to six positives per month. One of the positives was picked up on a piece of food contact equipment. There is no testing of finished product as it is not seen as a ready to eat product but a ready to cook. How concerned should you be with that level of L. mono drain contamination within a ready to cook facility. Again I mention I am not familiar with high care facilities but I know on my low risk facility (bread product) we got 1 detection of L. mono in 15 years that resulted in huge spends on drain redesign, floor surface replacement and floor cleaning equipment. TIA