Listeria Harborage and Contamination
Per Michael Cramer, “We want to prevent harborage of food pathogens that can contaminate our foods, rather than try to detect them solely with end product testing.
Listeria is an organism that can be found almost everywhere in the environment. This means that it can potentially be introduced into the manufacturing facility from ingredients (raw meat and poultry), personnel (shoes, hands) or materials that travel through the plant (pallets, material handling equipment). The key to control is to understand the means by which it is introduced, where it can harbor and how it may be spread. This is presented in Cramer’s Corner: Chapter 4 Slide 3.
Understanding where to look for Listeria monocytogenes, how it can harbor and then preparing methods for minimizing or eliminating are critical to preventing contamination of foods prepared in the facility. These are presented in detail in Chapter 4 of the book Food Plant Sanitation, entitled “Control of Listeria in Food Manufacturing”.”
Listeria is a ubiquitous bacteria, meaning, it’s found almost everywhere in nature
As a result of this Listeria may be continually introduced into the manufacturing environment from:
– Ingredients – specifically raw meat and poultry
– Shoes – worn outside the plant then allowed to be worn in the plant
– Pallets – wood absorbs and can carry contaminants into the plant
Once introduced it can move through the environment on personnel shoes, material handling equipment, water (splash, aerosol) and poor GMP’s
Listeria often finds niches where it can harbor and then spread to product contact surfaces, in-process materials or finished product