When it Comes to Pathogens: Expect the Unexpected!

I have been travelling a bit over the last few months, which is quite a challenge when the garden goes on a massive Spring growth at the same time. However, I treasure meeting industry people and experts face to face and discuss environmental monitoring (amongst other things). Because you can teach an old dog new tricks, and whilst I’m passionately promoting a risk-based and targeted monitoring approach, I'm well aware that there are different views and more than one way to set up a good monitoring program.?

One of those different views is around the monitoring of the secondary pathogen. The secondary pathogen is the pathogen that is not the primary risk to the product. For example, in a milk powder factory, the primary pathogen is Salmonella (because it is a low water activity product) and the secondary pathogen is Listeria monocytogenes and for cheese, this would be the other way around (Listeria m. is primary and Salmonella considered secondary).

The main question I get is: “Jack, when we go on our bear hunt, why would we want to spend any money, looking for the secondary pathogen!?”. It’s a valid point and my standard response is “Because we don’t want to host any in-house pathogens, even if they are a lower risk to the product!?” Unfortunately, I have never come across a real-life example to back this up.

Until last month!!

You see, another benefit of meeting my peers face to face is sharing factory insights. I always feel very privileged when people share their real-life challenges and lessons with me. So last month, at a conference, I was pulled aside by a long-time friend, who shared one of his latest experiences in the field. He actually said that he was looking forward to my LinkedIn article on the topic!

And so, in the spirit of Christmas, here’s my article gift to him (and all other interested parties).

My friend shared the story of a low water activity ingredient, which is added to other food products, with more moisture. The factory was happily making their product and complied fully with their customer specification, which asked for Salmonella negative (as expected). Neither party contemplated testing the ingredient for Listeria, because, as mentioned, it’s an ingredient with a low water activity.

However, when the customer started detecting Listeria in their final product, things got interesting. As part of the root cause analysis, the customer tested all the ingredients and to everyone’s surprise they detected Listeria in the low-moisture ingredient. In other words:

The ingredient with the low water activity was contaminated with Listeria, which managed to survive and subsequently contaminate the final product of the customer!

Fortunately, the supplier of the ingredient quickly found the root cause, which they did not find before, because they never looked hard enough for Listeria in the factory environment.

And there it is, a real-life example as to why we should keep an eye on that secondary pathogen in our factory (and also fully understand how our customers use our product), because with pathogens:

We don’t know what we don’t know; and we should expect the unexpected!

Merry Xmas and Happy New Year

Jack

Disclaimer: This article is my personal opinion and does not reflect or represent the opinion of my employer(s).