Guest Blog: Listeria monocytogenes and Food Processing Equipment, 1/3

The following Guest Blog first appeared as a three-part series in French on Le Blog d’Albert Amgar, a regular feature on, and is reproduced here in English (translation by Phyllis Entis) with the kind permission and cooperation of its author, Albert Amgar.

Five Canadian provinces experienced
an outbreak of listeriosis in July and August 2008 that caused the deaths of 22 people. The outbreak was traced to refrigerated, ready-to-eat meat products manufactured by Maple Leaf Foods. An independent investigation report (pdf format) into the background and handling of the outbreak was commissioned in January 2009 and released on July 20 2009. The following is a brief summary of the findings.

“Ironically, Listeria is sometimes described as a bug of clean plants because some believe that intense sanitizing kills off the bacteria’s natural predators. This belief, however, has not been demonstrated to be true and contributes to ineffective Listeria control procedures.” Dr. Bruce Tompkin, Member of the Listeriosis Investigation Expert Advisory Group 

What was the origin of the outbreak? According to Michael McCain, President and CEO of Maple Leaf Foods Inc., “It was a failure to analyze test data that we weren’t even obligated to collect – a failure on our part to analyze that data and look for root-cause analysis, investigate and follow-up on individual trends, to look for patterns so that we could find the bacteria that we couldn’t see inside these facilities, and end up with a different result. It was more a failure to analyze those findings for a root cause, and a failure of those protocols, than it was a failure of inspection, per se.” This admission is made more striking, because Maple Leaf is one of the few companies since the close of the 1990s to have developed a HACCP plan. Nevertheless, as we know, a HACCP plan does not confer immunity against contamination.

One of the concerns for those interested in process sanitation for refrigerated, ready-to-eat (sometimes also referred to as high-risk) products is to understand how to improve their own systems for managing food safety. According to Bruce Tompkin (2004, Asept, Laval), “A higher prevalence of Listeria on surfaces in contact with the product indicates a higher potential for the presence of Listeria monocytogenes in the product.” This observation goes to the heart of the problem of equipment sanitation!

The independent investigator wrote: “I am calling for swift and significant action in key areas that are critical to food safety – the culture of food processing companies, the design of food processing equipment, the rules and requirements for food safety set out by the federal government as well as governments’ capacity to manage national foodborne emergencies.”

Chap. 5, rec. 14: “Increased coordination and improved communication about food processing equipment is needed among the manufacturer, the food processor and the CFIA regarding design specifications and the validation of sanitation procedures.”

All meat processors should ensure that new and existing equipment is and remains appropriate for the intended use. Sanitation methods should be validated and implemented by meat processors in consultation with the equipment manufacturer, with a particular focus on the intended use and the products being processed on each piece of equipment.

This requirement already is embedded in European regulations; but, to the best of my knowledge, it is seldom, if ever, applied. Thus, Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast), mandates the following: “The instructions for foodstuffs machinery and machinery for use with cosmetics or pharmaceutical products must indicate recommended products and methods for cleaning, disinfecting and rinsing, not only for easily accessible areas but also for areas to which access is impossible or inadvisable.”

Watch for Listeria monocytogenes and Food Processing Equipment, 2/3

About Albert Amgar: Albert Amgar lives in Changé near Laval in Mayenne, France. He worked as young scientist at the Parasitology and Tropical Medicine Service of the Pitié Salpétrière Hospital and later spent 12 years in the pharmaceutical industry. In 1989, he became director of a new association of agro-food industrialists named ASEPT in Laval (France). He was the general manager of ASEPT until his recent retirement.

2 thoughts on “Guest Blog: Listeria monocytogenes and Food Processing Equipment, 1/3

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.