You must, at a minimum, take the following actions if you detect Listeria species or L. monocytogenes in the growing, harvesting, packing, or holding environment:

(a) Conduct additional testing of surfaces and areas surrounding the area where Listeria species or L. monocytogenes was detected to evaluate the extent of the problem, including the potential for Listeria species or L. monocytogenes to have become established in a niche;

(b) Clean and sanitize the affected surfaces and surrounding areas;

(c) Conduct additional sampling and testing to determine whether the Listeria species or L. monocytogenes has been eliminated;

(d) Conduct finished product testing when appropriate;

(e) Perform any other actions necessary to prevent recurrence of the contamination; and

(f) Take appropriate action to prevent any food that is adulterated under section 402 of the Federal Food, Drug, and Cosmetic Act from entering into commerce.