Listeria is a major food safety concern for the meat and poultry industry, and those involved in processing must put a special focus to prevent and control its spread.

Kris Olson, corporate account manager, Food and Beverage, Ecolab, discussed the four tenets of Listeria prevention and control during the Listeria Monocytogenes Prevention and Control Workshop, held January 31 at the International Production and Processing Expo (IPPE) in Atlanta.

“There’s a lot of different things that go into making Listeria a pathogen of major concern for us,” said Olson. “Not only the impact on the health of human beings when it infects somebody, but it’s a natural incurring environment, so we can’t take it out completely. We’ve got to make sure that we do everything possible to control its impact within our plant environments,” Olson said.

1. Prevention of entry

Much can be done to control incoming contamination, as there are many potential sources of entry. Those can be people, equipment, materials, ingredients or packaging. Because of this, it is vital that each plant has zoning and traffic patterns, an effective environment care program, and a personal hygiene program for all who enter the plant.

2. Prevention of growth

Olson stressed that in order to prevent Listeria’s growth, plant workers must identify and execute appropriate sanitizing programs.


“What’s the surface that you’re dealing with? ... You don’t want your cleaner or your sanitizer to create harborage points because it’s not compatible with the surface that you are cleaning,” he said.

3. Eliminate harborage points

There are many “nooks and crannies” in a processing plant that can be harborage points. According to Olson, “Poor sanitary design and maintenance will negate the best cleaning programs.”

Examples of harborage sites include hollow rollers, bad gaskets, bad welds, sprockets and gears, materials of different kinds bolted together, conveyor wear strips and guides.

4. Prevention of spread

A lot of the same principles to prevent entry and growth also apply to the prevention of Listeria’s spread, but one of the biggest keys is to take a deeper look at the main factors of sanitizing. These include finding the right chemistry for sanitizers, being sure you have the appropriate temperature and time required to address the issues, and to apply complete coverage of disinfectants to all surface areas.