10 replies to this topic

[Mar]

Hi food micro people,
I have a problem going on in a ready-to-cook pastries plant. Some lab reports (3) came out positive for Staphylococcus coagulasis+ . this was not the first time this happened. last year, the same problem happened in 3 different final products. Everyone was sent to the doctor for oro-faringeal swabs that came all negative. What can I do to stop the contamination? I already destroyed the envolved batches, but i am afraid this continues happening. can anyone help, please?
Mar.

[GMO]

It's not from the raw materials is it?

I suppose your actions so far have all been retrospective too, (i.e. swabbing and waiting) I'd audit them to death!!!

[Charles.C]

Dear mar,

I presume you mean S.aureus, coagulase positive.

I presume also that this is not RTE.

Yr post would be more readily interpretable if it contained some numbers (eg 3.6MPN/g is not quite the same immediate impact as 3600) and perhaps a little history, eg new process?.

I presume yr spec. is not zero tolerant for S.aureus, C.+ ?

Rgds / Charles.C

[Mar]

Hi GMO & Charles.C,

in fact there was no process change.
the final product is ready-to-cook, so, it will need a cooking step before being ate. this doesn´t mean anything, since s.aureus produces termo-stable toxin.
What showed up was 10³ or 10⁴ cfu/g counts. I would be much more relaxed if they haven´t showed up at all.
Mar.

[divyjyot]

[quote name='Mar' timestamp='1331052758' post='52341']
Hi GMO & Charles.C,

in fact there was no process change.
the final product is ready-to-cook, so, it will need a cooking step before being ate. this doesn´t mean anything, since s.aureus produces termo-stable toxin.
What showed up was 10³ or 10⁴ cfu/g counts. I would be much more relaxed if they haven´t showed up at all.
Mar.
[/quote ]

Hi Mar

Try coducting air sampling of your packaging area and take swabs of your equipments product, could help you to trace the source of contamination.

Divya

[Bawdy01]

Have you tried doing micro tests on your raw materials looking for coag +ve staph? I assume that your process does not involve any cooking/heating?



Regards,

Bawdy.

[Mar]

Hi all,

answering your queries:
Bawdy01: the process does not include a cooking process. never tested the raw ingredients.
Divya: air sampling for staphy? is it possible that the contamination route is aerogenous? never heard of for staphy.
tks,
Mar.

[Charles.C]

Dear Mar,

never tested the raw ingredients.

Very unusual.!

I assume this is a meat pastry ?

So how do you know if yr raw material meets specifications ? I presume you have micro.specifications for S.aureus etc in raw material?.
Meat not my speciality but usually IMEX, mM of the order of 100,1000MPN/g for S.aureus. From memory toxin risk is improbable below 10exp5/g.
S.aureus is typically a poor micro. competitor so I expect the figures you quote are well above normal for (hopefully!?) the majority of yr results. Normally, i guess you get <100 MPN/g, maybe even <10/g.?

Basically you need some routine (input) data to set a baseline. (I guess you have no in-house lab.(?) which does slow things down a bit).

Rgds / Charles.C

[GMO]

<20 is typical for cooked but I'm glad I asked the question regarding whether it was from the raw materials! Just like humans, animal skins will often carry s. aureus too. What do your raw materials suppliers say the loading 'should' be less than? Are you setting yourself an unrealistic target? That said, although you're looking at 10^5 or 10^6 for toxin, 10^4 doesn't feel comfortable.

What is your temperature control like? s. aureus can grow down to 7 degrees but toxin production is from around 10. So lowering the temperature in your whole chain might be a plan.

Personally I think air sampling wouldn't be much use.

[gloriaeho]

Hi Mar,

As suggested by in one or two other posts, it may be a good idea to look towards your primary ingredients for a source. For example, raw meats, vegetables, etc. All are typical sources of Staph Aureus. I would also ask whether there are any hand contact surfaces that your production staff come into contact with, that are also shred with non-food production staff, as this could be a source of Staph Aureues transfer to the production environment. It might be worth checking to see if there were any visitors to your premises, in the days preceding the production of the affected product batch, as any of your visitors may have been the source, include maintenance workers, auditors, guests, clients, etc. Finally, as suggested by one or two other posts, it would certainly be worth carrying out a further sampling exercise on your products to see whether the problem is a persistent one, or an unusual occurrance.

Hope this helps.

Kind Regards

Gloria

[George @ Safefood 360°]

Hi Mar,

These micro issues are always difficult to pin down but determination of the route of contamination is your priority. Focus has to be on:

1. Food handlers.

This is the main root cause of contamination of foods leading to food poisoning from S.aureus. Although your first tests have show clear results I would do further investigation. Perhaps try a different laboratory.

2. Raw materials

Do a little research and see if any of the ingredients you use have in the past been associated with S.aureus issues. e.g. egg.

3. Temperature control

Double check the cold chain for the product. As temperatures increase so can toxin production.

4. Environment

Verify that difficult to clean areas have not set up as a potential source for S.aureus.

5. Product formulation

Check the product formulation has not changed e.g. salt content and pH (You have eliminated a hurdle for S.aureus)

George