21 replies to this topic

[a_andhika]

Dear Forum,

Could anyone help me to provide list of products that can be ensured contaminated with Salmonella? I would like to validate a new media that can detect Salmonella easily. I am already validate the media with products that didn't contain Salmonella (compare the result with certified Lab). But I'm still in a doubt whether my media could really detect Salmonella or no, if I didn't test it on a product that contaminated with Salmonella.

Thank you very much.

Regards,


Arya

[GMO]

Depends on how good your farmers are but if you check 10 raw chicken samples, at least one will probably be positive for Salmonellae (and probably all will be positive for Campylobactor).

I could say Cadbury's chocolate but that would just be churlish of me.

[Charles.C]

Dear Arya,

As per GMO, from memory, the typical level of occurrence of salmonella in UK chicken is around 10% so 10 random samples should do it nicely (but perhaps depending where you are). Clams are also often unfortunately a good source IMEX, particularly if acquired in a suspiciously unhygienic looking environment.

More precisely, a fairer evaluation requires some idea of the density of salmonella in the product since this should be aligned to the detector's specification, including things like any specified preliminary boosting steps as per various standard procedures. Unfortunately, this tends to require some expertise IMEX.

It is possible to buy samples of relatively low-pathogenic Salmonella species if you simply want to test yr kit, assuming you have an appropriate handling/disposable set-up. Another option if you hv a contact in the local Public Health Department is to enquire over "borrowing" an agar slant streaked with a similarly suitable bacteria since most official labs have to maintain such items for validation purposes. They might even have a suitable product sample to offer if you can show you are a bona fide applicant.

Rgds / Charles.C

[AS NUR]

Dear Forum,

Could anyone help me to provide list of products that can be ensured contaminated with Salmonella? I would like to validate a new media that can detect Salmonella easily. I am already validate the media with products that didn't contain Salmonella (compare the result with certified Lab). But I'm still in a doubt whether my media could really detect Salmonella or no, if I didn't test it on a product that contaminated with Salmonella.

Thank you very much.

Regards,


Arya

Hallo Arya...

Apa Khabar ?.... To ensure which food that salmonella can contaminate.. you have to know about salmonella requirement for life and growth.. and after that you can compare is your product suitable for salmonella growth?.... you can find the salmonella information in "bag bug Book" at FDA web site.. and below is list of product for bacterial growth.....
Hope can Make you clear ....

Attached Files

•  foodborne_illness__bacterial_Agent_.pdf   318.39KB   58 downloads

[Simon]

Hallo Arya...

Apa Khabar ?.... To ensure which food that salmonella can contaminate.. you have to know about salmonella requirement for life and growth.. and after that you can compare is your product suitable for salmonella growth?.... you can find the salmonella information in "bag bug Book" at FDA web site.. and below is list of product for bacterial growth.....
Hope can Make you clear ....

Great document ASNUR, thanks for sharing.

Regards,
Simon

[cazyncymru]

I could say Cadbury's chocolate but that would just be churlish of me.

OHHHH GMO....your almost as bad as me! i still won't eat the stuff!

[a_andhika]

Hallo Arya... Apa Khabar ?.... To ensure which food that salmonella can contaminate.. you have to know about salmonella requirement for life and growth.. and after that you can compare is your product suitable for salmonella growth?.... you can find the salmonella information in "bag bug Book" at FDA web site.. and below is list of product for bacterial growth..... Hope can Make you clear ....

Kabar baik AS NUR...Thank you very much for the PDF:)
Yes, my new kit is made only for detecting Salmonella, not for other kind of bacteria. So I think of course it's suitable for the growth.
Thank you very much for the feedback guys.. Now I have some opening about what kind of test that I need. Wish me luck
By copy to GMO and Cazy, Cadburry that contaminated with Salmonella were pulled out aren't they? And it only comes from one of it's factory right? Gosh... I am still ate that thing!

Edited by Simon, 12 June 2008 - 07:33 AM.
Some text that should have been placed inside the quotes was outside

[Simon]

By copy to GMO and Cazy, Cadburry that contaminated with Salmonella were pulled out aren't they? And it only comes from one of it's factory right? Gosh... I am still ate that thing!

I eat cadbury's chocolate all the time and I mean all of the time. I never stopped. I happen to have inside info on Cadbury's food safety programme and it is improving fast, they are throwing a lot of resource at it. It's not perfect, but then who is?

Simon

[AS NUR]

oops.... i like chocolate.. but i am not cadbruy's customer... my fave is MARS.... I hope no salmonella inside of MARS....

[cazyncymru]

oops.... i like chocolate.. but i am not cadbruy's customer... my fave is MARS.... I hope no salmonella inside of MARS....

I would think you are very safe to eat chocolate, especially cadburys. I've no doubt that food safety is at the top of Cadburys agenda, and that they are proactive in ensuring that they don't have a similar problem.

The food safety team at cadburys, i suspect, were made scapegoats for what may have been a commercial decision to release the product into the market place. if there had been a serious effect on public safety, im sure that the authorities would have made cadburys withdraw all of their products and not just the ranges that they did, and the seriousness of the outbreak would have been reflected in their fine. ( a Million is nothing compared to some of the fines issued to other companies for what may be less serious breaches) These are my views, and its easy to be shocked and comment when you read what the media "half" reports!

They were unfortunate in that they had a problem at one of their factories which was supplying a raw ingredient to others within the group. i know that when someone in a similar industry to mine has a problem, we all end up scurrying about to ensure it can't happen to us. its easy to become complacent within your industry; how many times have you passed something that is blatantly wrong in your factory, and done nothing?

As an aside, i don't eat any chocolate as i'm diabetic

"but for the grace of god"

[a_andhika]

how many times have you passed something that is blatantly wrong in your factory, and done nothing? As an aside, i don't eat any chocolate as i'm diabetic "but for the grace of god"

Hello..
Its interesting to see how this topic groom into another topic:)
Yep, bad things happens, and we cant avoid it. Im sure Cadburry and other big companies has a strict regulation bout FSMS, but who knows? But Im still disagree about the "blatantly wrong". If it means someone's life, I guess we can tolerate nothing.

Anyway, can we discuss another positive-contaminated-Salmonella-products? Like poultry or dairy perhaps? Maybe I can get clue for my Kit Project:)

Regards,


Arya

[Charles.C]

Dear Caz,

not intended to create a new thread !

I can accept yr “business’ comment but it is also interesting to note some of the very debatable scientific comments regarding food safety which occurred at that time, eg -

"You would need to be looking at in the order of a million cells of salmonella in 100g to cause a stomach upset."
The company found 0.3 cells per 100g in the crumb - far below the "alert level" of 10 cells,….. adding that people who had eaten some of the chocolate "should not worry".

http://www.telegraph...-chocolate.html

I would be really interested to see the validation data for the above (I assume correctly quoted) statements.

The kit under present discussion also might have not detected the above levels . Specs ??

Adding other factors like sampling, such incidents emphasise that we have to be able to rely on (good) HACCP.

Rgds Charles.C

[GMO]

I am in the position of having worked for a major competitor of Cadbury's and I even have some HACCP training notes still with a slide saying "there that there is no safe level of Salmonellae in chocolate". Something strange happens to Salmonellae in chocolate meaning that very low levels cause infection and have caused deaths, you're looking at cells, not millions of cells as they have stated.

In the past outbreaks have been proven at the level of 10 cfu g-1 which means there were 1000 viable cells in 100g bar, however, remember the lower the contamination, the harder it is to detect. In that outbreak, it may have been that lower levels were causing illness but weren't detected in the chocolate. From my extensive experience they had absolutely no basis to say "You would need to be looking at in the order of a million cells of salmonella in 100g to cause a stomach upset." That's what makes me angry about the whole thing. If I knew that in a chocolate company over 8 years ago, so did they.

Ok - this is old data but this is from some HACCP training back in 2002:

Salmonella cases from chocolate

1970 - 110 in Sweden (from poorly processed cocoa powder)
1973 - 200 in USA (cross contamination)
1982 - 245 in Italy (contaminated water)
1986 - two outbreaks numbers unknown Canada (from Belgian chocolate)
1987 - 300 in Norway
2001 - >230 in Germany and some in Denmark and Sweden (cause unknown, source Aldi)

I think I've made my point. As a company, they were irresponsible and arrogant. They had no basis not to recall every product which was made with the contaminated crumb (which they didn't). It's like saying you've put cooked chicken into several ready to eat products and later the chicken shows on a work in progress micro check to have contained Salmonella spp. but you only recall the products where the finished product check was positive! That is so not how microbiological contamination works, a leaky pipe will probably mean patchy contamination. Oh and I completely agree with Caz; no technical person would be pushing for this to be released, they totally scapegoated.

Edited by GMO, 12 June 2008 - 03:00 PM.

[Simon]

Do we think they have learned their lesson?

[cazyncymru]

Do we think they have learned their lesson?

Question is have we ALL learnt the lesson.......you just can't be complacent when it comes to food safety.

I for one have no problem in questioning production / engineering / laboratory if i think that there may be compromising of food safety.

caz x

[a_andhika]

The kit under present discussion also might have not detected the above levels . Specs ?? Adding other factors like sampling, such incidents emphasise that we have to be able to rely on (good) HACCP.

The new kit under this discussion is used for the detection of Salmonella spp. in food, veterinary, and environmental samples. Quoting the product information: "This media principle lies on the detection of Salmonella ability to decarboxcylate L-Lysine and more importantly their motility". Obviously, the kit was made for qualitative result. Which is also supported by another quotation: "On this media, Salmonella produce a red halo of growth around the orginal point of inoculation." As an addition, the media itself was green-colored.

The thread from Charles pops another questions in my head. Does the media only shows postive result when Salmonella occur in certain level? And if it does, does the level regarding with a harmful level? And what the limitation of harmful level itself?

I know those questions should be pointed to the salesman, but could anyone gives me another hint about qualitative media? Does it only read when bacteria reach certain quantity, or it will react no matter how small the quantity or the activity was? Thank you.


Regards,


Arya

[Jean]

The media used for detecting Salmonella will be enrichment media and selective media. The sample will be inoculated first in an pre-enrichment media (Lactose broth), enrichment media (Rappaport media) and then inoculated into selective media like XLD, DCA , BSI followed by confirmation using chemical tests (TSI, LIA ). There are API test kits available too.
This helped me to refresh with my Microbiology analysis.

I hope this helps.

[Charles.C]

Dear a_andhika,

AFAIK any commercial method which is, for example, AOAC approved should have a known sensitivity etc since this is a basic part of the validation process.
If you look up a few commercial methods on the net, such info is usually part of the specification. From memory, the typical target for the traditional methods / associated enrichment procedures used to be an ability to give a (correct) positive result at around 1cfu/g in the original material. Newer methods can do better than this. The question of false positives / negatives (sensitivity-specificity) is also relevant as you will see if you study the typical validation methods. There is a forum thread discussing all these parameters ( somewhere ) with links included to examples of commercial specs / AOAC validation procedure (available on the net [*** see "added" at end]).
These are all questions for the salesman of course, one good one IMEX is to request details on which product types have been used for official validation testing and with what (documented) results. I have sometimes discovered that my material has not yet been evaluated or is even contra-indicated for the application by AOAC. This was "unknown" to the salesman and also apparently to various other companies who were being quoted as examples of satisfied customers .
As far as "harmful" is concerned, I think all (2000+) species of salmonella are considered to be "pathogenic". "Danger" levels hv been found to vary from a few cells to many depending on the exact situation, eg species, matrix, consumer sensitivity. Legislation mostly applies a zero tolerance (ie not detected by an approved sampling/testing plan).

added - the ref is -

http://www.aoac.org/...2Guidelines.pdf


Rgds / Charles.C

[a_andhika]

The media used for detecting Salmonella will be enrichment media and selective media. The sample will be inoculated first in an pre-enrichment media (Lactose broth), enrichment media (Rappaport media) and then inoculated into selective media like XLD, DCA , BSI followed by confirmation using chemical tests (TSI, LIA ). There are API test kits available too. This helped me to refresh with my Microbiology analysis. I hope this helps.

Thank You Jean.
Well, my new kit is much more simple, a selective media I suppose. I just inoculate the sample on the media, and incubate it on 41oC for 24H. It simple and might not give much more information than positive or negative contaminated. How so ever, thats what our need right now. But I'll come look for another information.

And for Charles, thank you very much for the hints. Yeah, I think I need to ask the salesman about the validation of his media. FYI, he declare the Certificate of Approval of his supplier's Laboratory. It certified with ISO 9001:2000. Is it fair enough? (I presume yes)

Regards,


Arya

[Charles.C]

Dear arya,

Labs are normally certified to ISO17025 these days ?!

Not sure exactly what yr media is but one immediate need-to-know is information about possible false positives/negatives for your kind of product. A quick procedure for screening colonies IMEX is via TSI/LIA as you know and then slant purification (if not already done) with subsequent serological polyvalent O and H testing. The full battery of biochemical tests are necessary for completeness but sera are quick indicators and often not so expensive these days, especially if locally derived. Only drawback to sera IMEX is a bit of practice may be required for positive interpretations in some cases.

Rgds / Charles

[a_andhika]

Dear arya, Labs are normally certified to ISO17025 these days ?!

Whoops.. Sorry, my bad... Incomplete info... :p Its not the Testing Procedure of that Lab that certified with ISO 9001:2000, but the QMS for designing, manufacturing and sales of their reagents and instruments.

Well, for most of part, Im sure they are selling good (read:validated) stuff. Its a worldwide company afterall. All I want to do just see the positive-contaminated reading on that media. But after get another opinion from forum members, I think it would be wise to consider other procedures/media:)

Regards,


Arya

[AS NUR]

Dear Arya...

You have to used media for known and credible manufacturer like MERC K.. i think that media is valid for micro analysis

or you can compare with FDA (bad bug book) .. You can find what the media inside for some microbioloigical analysis.. and compare with the supplier one