8 replies to this topic

[ebb30]

Hi everyone,

 

There is a small debate about Listeria in drains and where it comes from. One school of thought is that it is just simply in drains and we have to be careful that it does not come out of the drains; the other school of thought is that it is being carried into the factory from outside and is concentrating in drains since that's where everything from the floor ultimately ends up. Once in the drain, it can create biofilm and multiply, and we have to be careful that it does not come out. 

 

I am trying to find articles that address this but am having a hard time. Mostly I find articles that talk about how to get rid of listeria in the drains, but none seem to address where it is coming from. 

 

It doesn't seem like a big deal, but I am a firm believer that Listeria comes in from our shoes and concentrates in the drains, so even if we clean all the drains regularly, we are still not addressing the root cause. A good preventive program, in my opinion, would not only address regular drain cleaning, but also foot baths etc. that prevent contaminants from outside ever entering the plant floor. 

 

Any thoughts? Anyone find any articles I can use to support or disprove my claim? 

 

Thank you!

[Charles.C]

Hi everyone,

 

There is a small debate about Listeria in drains and where it comes from. One school of thought is that it is just simply in drains and we have to be careful that it does not come out of the drains; the other school of thought is that it is being carried into the factory from outside and is concentrating in drains since that's where everything from the floor ultimately ends up. Once in the drain, it can create biofilm and multiply, and we have to be careful that it does not come out. 

 

I am trying to find articles that address this but am having a hard time. Mostly I find articles that talk about how to get rid of listeria in the drains, but none seem to address where it is coming from. 

 

It doesn't seem like a big deal, but I am a firm believer that Listeria comes in from our shoes and concentrates in the drains, so even if we clean all the drains regularly, we are still not addressing the root cause. A good preventive program, in my opinion, would not only address regular drain cleaning, but also foot baths etc. that prevent contaminants from outside ever entering the plant floor. 

 

Any thoughts? Anyone find any articles I can use to support or disprove my claim? 

 

Thank you!

 

Hi ebb,

 

I'm afraid it is probably over-simplistic to regard shoes as the root cause of L.monocytogenes entering a Food Plant environment.

.

I think that the general opinion regarding sources, vectors, accumulation of L.monocytogenes (and Listeria) in food plants is "multifactorial".

 

Afaik L.monocytogenes/Listeria is currently accepted as being a ubiquitous environmental resident/contaminant.

 

This FDA document (2008) overviews the general situation -

 

http://www.fda.gov/F...P/ucm073110.htm

 

Among the 500,000 google hits for L.mono/food, this 2015 document for the Dairy Industry looked quite impressive in scope and presentation regarding "Prevention and Cure"  -

 

 L.monocytogenes - Guidance-for-the-US-dairy-industry-10-19-15.pdf   2.43MB   99 downloads

 

Regarding drain-oriented  threads-

 

http://www.ifsqn.com...mentals-drains/

 

http://www.ifsqn.com...ns/#entry102837

 

http://www.ifsqn.com...ning-of-drains/

[Ryan M.]

Well...you need to break it down to the likely entrance points of listeria.  Typically, and more often than not it is coming in from personnel and raw materials.  It is only ubiquitous if one let's it be in their facility.

 

As Charles pointed out, it is multifactorial, so you have to assess the risk in your facility and operation.  That may include doing a lot of environmental swabbing to determine pathways.

 

As you pointed out the drains are the central point so they do need to be addressed, and the employee traffic and controls.  What about raw materials?  What about any secondary or tertiary containers that are being reused?  What about maintenance activities and their operations around the facility with parts and equipment?  Is the process enclosed or is product/materials exposed/open to the environment?

 

There are a lot of things to consider.  The resources Charles posted are very good, especially the dairy guidance with listeria.

[FurFarmandFork]

With FDA's new stance on "if it's in your plant, it's in your product", source is irrelevant, and the ultimate conclusion is that boot washing or captive footwear is now, for all intents and purposes, required in high-risk facilities to eliminate transient listeria entry to help you really find out whether you have harborage or not.

 

The comments above are all spot on, and because of how ubiquitious Listeria is, it's going to come in from ingredients, harborage spaces, and occasionally on dusty shoes. Unless you address all sources and make an attempt to eliminate it from your plant, eventually FDA will find it and assume it's in your product, read the recent warning letters concerning listeria findings to fully appreciate FDA's zero tolerance on this (L mono, not just listeria genus).

 

One option worth exploring, rather than swabbing drains as has been traditionally done, is to borrow from poultry salmonella samping and wear sampling "socks" in each area of your plant, avoiding the drains. Example description of this method: https://www.ncbi.nlm...les/PMC1764201/

 

In this way, you can grid out your plant by room, or by walking pathways and determine whether it accumulates on your walking areas or somewhere else in your plant, and you capture a lot of "floor" information without worrying about whether you have sampling bias from concentrations in your drains.

[Ryan M.]

The sampling socks are very interesting...where can these be had?  I conducted a cursory search on the internet with no success.  These would be perfect for our facility.

 

With FDA's new stance on "if it's in your plant, it's in your product", source is irrelevant, and the ultimate conclusion is that boot washing or captive footwear is now, for all intents and purposes, required in high-risk facilities to eliminate transient listeria entry to help you really find out whether you have harborage or not.

 

The comments above are all spot on, and because of how ubiquitious Listeria is, it's going to come in from ingredients, harborage spaces, and occasionally on dusty shoes. Unless you address all sources and make an attempt to eliminate it from your plant, eventually FDA will find it and assume it's in your product, read the recent warning letters concerning listeria findings to fully appreciate FDA's zero tolerance on this (L mono, not just listeria genus).

 

One option worth exploring, rather than swabbing drains as has been traditionally done, is to borrow from poultry salmonella samping and wear sampling "socks" in each area of your plant, avoiding the drains. Example description of this method: https://www.ncbi.nlm...les/PMC1764201/

 

In this way, you can grid out your plant by room, or by walking pathways and determine whether it accumulates on your walking areas or somewhere else in your plant, and you capture a lot of "floor" information without worrying about whether you have sampling bias from concentrations in your drains.

[FurFarmandFork]

You'll want to find the approved methodology for the specifics, but it looks like you can purchase lengths of "sterile tube gauze".

[Scampi]

perhaps this article is worth a read  http://www.fsis.usda...pdf?MOD=AJPERES

we use boot dips with a quat in them. employees must hit them (placed in front of handwash sink)

[ebb30]

Thank you everyone, there are a lot of good articles here! 

 

I agree that listeria can come from a great number of places, I picked shoes because it is the area I am focusing on right now. Trying to go about it in a systematic way, starting at the place that is least costly but has the greatest impact (just from the nature of our plant's layout and how easy it is for people to avoid any foot baths etc). Aside from sanitation procedures and a new drain cleaning protocol of course. 

 

I will look into the sock idea too, I like the concept.

 

Thanks again everyone!

[Dr.Des]

These guys do boot swabs http://www.tscswabs....uding-overboots

We have also used http://www.sodibox.c...cts-pxl-11.html in France, theirs is a much heavier duty boot swab than the above but obviously more expensive.

I'm not sure if either company trade in the US but I'd be surprised if you couldn't get something similar there.