Environmental testing plan - listeria & TVC

Hello all 

I am in the process of updating and reviewing an existing environmental schedule, micro isn't my area having been in low risk for many years and previous systems being established. 

We manufacture  RTE sandwich fillers and currently test areas such as scales/mixers/ benches/ choppers for listeria. 

My question is should we be conducting TVC and enteros on these items too or is listeria ok?

Many thanks 

Hi ;) 

Any retailers? 

;) 

No retailers just a medium small business, Salsa but working to BRC

Thanks 

Having worked in RTE high risk, environmental swab / monitoring did occur with TVC & enteros.

For guidance on various standards see:

Micro. Guidelines for Food Contact Surfaces - IFSQN

Regards

Thank you, so should we test for TVC & entros on a more regualar basis than listeria? we currently only seem to be testing listeria and no issues noted but would we benefit from TVC & enteros or recommended that we stick with listeria only?

:) 

Enterobacteriaceae are commonly used as indicator organisms that can indicate poor hygiene practices or failure of a manufacturing process, entero results are countable, this will give you a clear picture of hygiene practices. A TVC is not a specific micro-organism but rather a test which estimates total numbers of viable individual micro-organisms present in a set volume of sample. The TVC count may include bacteria, yeasts and mould species. Both Entero and TVC belongs to indicator groups.

For example, your environment can be Listeria free but doesn't mean that is free from gram-negative organisms (Entero) which are more heat resistant. Listeria swabs won`t be enough for your cleaning validation. Not sure what are you using for verification (usually ATP swabs) but without lab validation results this won't be enough.. 

Try to swab before and after

- tables underneath

- scale plate underneath 

- mixers 

- chopping boards 

;)

Dorothy87, Thank you. 

This is what I was thinking and from a previous role many many years ago we did more than listeria. I can not find any other results other than listiera swabs for all areas eg scales, drains, choppers. I have not come across any areas such as door handles and tables being tested either. It hasn't come up as part of our audits and the previous person doing audits didnt appear to find any non conformances in an entire year of audits so theres minimal evidence and continuous improvements. 

So should we choose to do TVC or enteros rather than both?

I would be swabbing the food contact areas post cleaning and disinfection for TVC as an indicator set of organisms, as others say, to show areas of poor hygiene.

Most plants use the retailer codes of practice to decide what to test.  In your case, I would argue as hygiene is extremely important that you go for TVCs as you could have presence of bacterial loading which aren't enteros.  With some products where loading is huge (e.g. cheese as it contains so many starter cultures deliberately) people look for enteros more but TVC is also not a bad thing to monitor.

When you designed your cleaning processes (if you were in role then) I'd have expected them to be designed using an indicator organism.  I.e. can your cleaning practices reduce bacterial loading to a safe level?  If you don't have records of this, it's a good idea to do them.  It also helps if you want to change chemicals or a process.

I would periodically test door handles and tables as well.  As you say, hand test points are also important as they could transfer to food.

I think as you've alluded to, testing only for Listeria spp is going to be hit and miss.  Most of the time it won't be there but not necessarily because you've cleaned well.  It's a good idea to test for it of course as better to find in the environment than actually in your product but still, it's quite a lagging indicator of the hygiene of your site.  It would be important as well to also have a more general verification of hygiene both through visual inspection and trending of swabs.