Managing Listeria: Practical Strategies for Real-World Processors

To effectively manage Listeria monocytogenes, facilities must both prevent its entry and control its presence through rigorous cleaning and monitoring practices.  Here are some key points to help with a listeria management program at your facility.

Keep Listeria Out

• Control entry points: Limit contamination from raw materials, footwear, equipment, air systems, and people by using dedicated gear in ready-to-eat (RTE) zones and manage airflow.
• Separate raw and cooked product: Use physical barriers and designated equipment to avoid cross-contamination, even in space-constrained facilities.
• Source smart: Work with suppliers who have strong Listeria control programs.
• Manage waste: Regularly remove organic materials and packaging waste to minimize microbial growth.

Control Growth and Spread: Seek and Destroy

• Target hotspots: Focus cleaning and sanitation on floors, drains, equipment crevices, cold storage areas, and overhead structures where Listeria thrives.
• Environmental monitoring: Conduct routine swabbing of high-risk areas, act quickly on positive results, and analyze trends to anticipate risks.
• Disrupt biofilms: Use scrubbing and abrasive tools to break down protective Listeria biofilms that resist sanitizers.

Enhanced Sanitation Strategies

• Go beyond basic cleaning: Rotate sanitizers to prevent microbial resistance, validate procedures through environmental swabbing, and consider dry steam or foam-based cleaners for hard-to-reach areas.
• Sanitary equipment design: Work with manufacturers to ensure machinery is easy to dismantle and clean, reducing potential harborage points.
• Employee hygiene and training: Provide routine education so all staff understand and consistently apply best practices in sanitation, cross-contamination prevention, and zone control.

In response to recent outbreaks, USDA-FSIS has introduced stronger Listeria control measures, including expanded testing, enhanced documentation, and digital recordkeeping requirements. These updates signal a shift toward proactive enforcement—and small and medium-sized plants, especially those under state inspection, should expect increased scrutiny.

What This Means for Processors

• Prepare for more frequent and targeted environmental sampling.
• Ensure your Listeria control programs are documented, validated, and consistently followed.
• Modernize sanitation and monitoring practices to align with evolving regulatory expectations.

As oversight intensifies and outbreaks continue to make headlines, small and medium-sized processors must shift from reactive compliance to proactive, verifiable implementation. This means embedding food safety into every layer of the facility—from sanitation protocols to employee training to supplier partnerships.

By staying vigilant and investing in effective sanitation, environmental monitoring, and post-lethality controls, processors play a critical role in keeping this stealthy pathogen in check—and in safeguarding the health of consumers who trust them every day.  To support this mission, the American Meat Science Association recently contributed an in-depth article to Food Safety Magazine, exploring the science behind Listeria monocytogenes, its behavior in food environments, and practical strategies for prevention and control. Watch for the article in the August issue!

Rob Maddock, Ph.D., Scientific Communication Resource Officer

American Meat Science Association