By Jim Byron
“When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in
numbers, your knowledge is of a meager or unsatisfactory kind.”
Testing for Listeria
in the year ahead.
resulted in modern food production systems that are very unlike systems of the
past. Think about it: How does the scale
and efficiency of your facility today
compare with 10, 20 or 30 years ago?
Small changes can have a significant impact, too. And with these changes, it is
important to discuss and investigate the
possible unintended effects of change. It
is possible that “improvements” to increase production efficiency may also increase the potential for deadly
pathogens such as Listeria to invade and
find harborage in your facility.
This article will review Listeria
testing—new developments that will be introduced to the market in the year ahead
and also the fundamentals of selecting a
Listeria test for your business. Listeria
can be a difficult pathogen to find. Successful food manufacturers make finding
Listeria a priority to be able to eliminate
it from their facilities. Having the right
Listeria test is an important part of the
overall process of improvement.
—William Thomson, Lord Kelvin (1824–1907)
These words are as true today as they were over a century and a half ago. As scientists, it is our nature to investigate, measure and improve. Numbers and data are
the basis of our informed decision making. Our need for
reliable data causes us to examine in detail the workings
of our surroundings and learn as we improve. When it
comes to Listeria, recent events involving the Listeria
outbreak associated with cantaloupe highlight the importance of our work to investigate, measure and improve. An examination of Listeria testing is appropriate,
and with new assays coming into the market, now may
be the time to completely rethink your past practices
and current programs.
Recent events remind us that we should ask ourselves
1. Is the data that I have sufficient and is it accurate?
2. Do current data represent the reality of my entire
food production process and facility?
3. What has changed in my business and how do I
quantify the impact of changes?
Things change. Our desire for efficiency and improvement drives change. In the world of food production, changes over decades of “improvement” have
Listeria monocytogenes is one of six
Listeria species. Listeria is able to survive for
prolonged periods in extreme environments where, once established, it is difficult to eradicate. Listeria is a
slow-growing organism, so Listeria tests
typically are characterized as taking a
long time to provide a result. The efforts
of test kit manufacturers have recently
resulted in many tests that provide results within 24 hours or less. Additional
activities by test kit manufacturers will
continue to bring innovation and improvements to the kits available in the
A comprehensive Listeria testing program should include both product testing and environmental testing. As food
safety professionals, we utilize two types
of tests for Listeria:
Listeria spp. testing for environmental samples. Because your goal in testing
is finding harborages that are potential