A new draft guidance, “Control of Listeria monocytogenes in Ready-To-Eat Foods: Guidance for Industry” was published by the US Food and Drug Administration (FDA) on January 13, 2017. Comments for this guidance were due July 26 and many trade associations and food manufacturers have submitted remarks. This draft guidance offers some excellent background information about Listeria control – more than simply using an environmental monitoring program (EMP). It also includes detailed coverage of many of the prerequisite programs (Good Manufacturing Practices) that are integral for Listeria control. In addition, it provides a comprehensive compilation of industry best practices and includes information about the validation of listeriostatic or listeriocidal formulations and processes.

Obviously, the new guidance is written with the Food Safety Modernization Act (FSMA) in mind. It specifically discusses some FSMA concepts, such as the term “environmental pathogen” and how to conduct a hazard assessment to develop a risk-based Listeria control program. Perhaps of greatest significance for FDA-inspected facilities, the new guidance introduces the concept of “one free pass” (also affectionately referred to as a mulligan), that brings FDA expectations more in line with the USDA’s regulations.

Basically, this means that if a facility tests for Listeria spp. on a product contact surface (also called Zone 1), the product would not need to be held at the facility pending test results. If a positive test for Listeria spp. is found, the product would also not need to be recalled. However, this is dependent on a consideration of the risk to public health. Also, if a second positive is found during follow-up testing of this same area, then the manufacturer may need to begin holding the product and the finished product might need to be tested for L. monocytogenes. This aligns well with the USDA guidance and matches the system that has allowed Ready-to-Eat (RTE) meat and poultry facilities to employ true “Seek and Destroy” programs that include testing Zone 1 sites without holding the product.

Another welcome point for the food industry is the clear emphasis on testing for the broader indicator group of Listeria spp. on food contact and non-food contact surfaces instead of testing directly for L. monocytogenes. This supports “Seek and Destroy” and offers a MORE conservative and effective method than focusing only on finding the pathogenic species. It is not required or recommended to identify which species of Listeria is present except under certain circumstances, such as for finished product testing. Also, if Listeria spp. positives repeatedly occur on food contact surfaces, the facility can determine whether or not it is important to further identify the contaminant to the species level based on risk.

Some of the industry’s concerns with the new guidance include its broad application to all RTE foods, not only the refrigerated, perishable foods that have been implicated in L. monocytogenes outbreaks. Additionally, the document is written for facilities that are using a wet sanitation cycle on a daily basis.  Extended run times or the production of low-moisture products that do not have wet sanitation are difficult to fit into the suggestions contained in the guidance. The definition of RTE remains the same as in as in 21 CFR:

“…any food that is normally eaten in its raw state or any other food, including a processed food, for which it is reasonably foreseeable that the food will be eaten without further processing that would significantly minimize biological hazards.”

The guidance only applies to RTE foods that are exposed to the environment after a kill step, don’t undergo a listeriocidal step in or close to the final package and don’t have a listeriocidal formulation.  However, this does not explicitly exclude shelf-stable foods, such as breakfast cereals and snacks (listeriostatic or not listeriocidal). It also does not exclude foods such as Individually Quick Frozen Vegetables, which have not normally been considered by the manufacturers as RTE due to the inclusion of cooking instructions on the packaging.

The new guidance does differentiate between foods that support the growth of L. monocytogenes and those that do not. The definition of growth is:

“A formulation is generally considered to be effective in preventing the growth of L. monocytogenes if replicate growth studies having samples pulled at various time periods throughout product shelf life show less than a one log increase in the number of L. monocytogenes.”  

This differs from the USDA definition, which is based on less than two logs of growth over a product’s shelf-life. This new FDA draft guidance, along with the new FSMA requirements and a general food industry trend of moving from dependence on finished product testing to environmental monitoring programs, means that EMPs are becoming even more critical and complicated. For example, many food manufacturing facilities are now monitoring multiple pathogens or indicator groups in several areas. Food manufacturers now need to implement documentation, strict adherence to written programs, robust data analysis including facility mapping, corrective actions, effective communication and flexible reporting.

Fortunately, Mérieux NutriSciences offers a software system designed specifically for environmental monitoring programs that can automate or simplify each of these critical areas. EnviroMap features automated scheduling, randomized site selection and predetermined corrective actions. These features allow manufacturers to spend less time on the day-to-day operations of their environmental monitoring program and more time looking at the big picture to spot patterns and trends. Mérieux NutriSciences saw success in improving our internal operations when we implemented EnviroMap in our labs. Read our free internal case study to about how EnviroMap helped us meet our unique set of environmental monitoring needs.


Meet the Author

Tim Freier, Ph.D
Division Vice President, Scientific Affairs and Microbiology, America, Mérieux NutriSciences

Tim Freier is the Division Vice President, Scientific Affairs and Microbiology, America at Mérieux NutriSciences. He has over 25 years of experience working in various food safety and quality related positions in food facilities and in the microbiology lab. Tim has worked extensively in the area of pathogen environmental monitoring and exploring and implementing new food safety technologies.

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