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Author Topic: Can we make a pathogen detector?  (Read 2012 times)

Offline Geezer

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Can we make a pathogen detector?
« on: 15/06/2011 08:07:45 »
The very sad events in Germany probably have a lot of people wondering how they can tell if their food is safe or not.

I was wondering, is it possible, or will it be possible in the near future, to develop some sort of device that can rapidly detect the presence of certain bacteria and/or their associated pathogens? I think there are some really innovative techniques being developed in this field, but I'm wondering if it's practical to develop a relatively inexpensive device that retailers, and even end users, can use to quickly confirm that their produce is safe.

My guess is it will be possible in the near future, but it's only a guess.


 

Offline CliffordK

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Can we make a pathogen detector?
« Reply #1 on: 15/06/2011 09:48:46 »
It depends on the contamination.

Something like Staph Aureus likely has enough bacteria and toxins that one could pick it up with a dye or antibody.  Or, perhaps one could pick it up even with the human nose.

However, one of the other topics suggested that Enterohemolytic E-Coli can be transmitted with as little as a half a dozen individual bacteria.  The only way to pick it up would be culture or PCR.  Random testing of produce might be able to pick up some sentinel cases.  But, say if 1 out of 100 employees is a carrier, then it might be difficult to pick it up.

The transmission of  Enterohemolytic E-Coli on steaks is unlikely, but technically hamburgers or hotdogs should never be served rare.

The ease of detecting other diseases would vary with their transmission mode.

If you look at the salad bar infections, there is always a question on where the infection originated.  Field, food service employee, or customer.

It would be an extraordinary undertaking, but one could do stool samples for Enterohemolytic E-Coli from both people and cattle.  The infections would be difficult to treat in carriers though.  And, with the international food markets, it would have to be a global effort to try to eradicate the bacteria.

There are some notes on the web of new Enterohemolytic E-Coli vaccines that are being tested in both people and livestock.  Perhaps it could be eradicated with an extensive vaccination program.  Or, at least the response to the disease would be less likely to be fatal.
 

Offline Geezer

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Can we make a pathogen detector?
« Reply #2 on: 16/06/2011 00:45:38 »
Thanks Clifford. I think there are some techniques for detecting very faint trace amounts of chemicals. I was wondering if something along those lines might work.

I wonder what sort of bacteria counts were in the sprouts that poisoned so many people in Germany. I would have thought they would be moderately high, but I really know very little about the subject.
 

Offline CliffordK

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Can we make a pathogen detector?
« Reply #3 on: 16/06/2011 01:34:56 »
The question is whether E-Coli is actively growing on vegetables, or it has entered a more inert stage waiting to be re-ingested.

Most of the data I've seen is that Enterohemolytic E-Coli is a result of surface contamination, and is not found inside of either steaks, or vegetables. 

I don't know if it can be transferred from soil to vegetable fruits without some mode of transfer, bugs, people, etc.

Perhaps there would be a way to bulk-wash your vegetables near the source, then test the rinse water for pathogens as the vegetables are being transported to market.

One of the problems is that there is very poor tracking of our food sources.  Things get so mixed up.  So, for example, if a single spinal cord is found with Mad Cow disease, it may result in millions of pounds of beef being destroyed. 

Likewise, it is very difficult to trace a disease like Enterohemolytic E-Coli back to a single farm or farmworker, then to go back and remove all the produce originating from only that farm from the shelves. 

Once they get to the stores, every single apple, for example, has a code sticker printed and attached to it.  Yet, even this code is insufficient to unambiguously determine the source, transportation, and processing of that apple.

It is still a big task to identify exactly what made a person sick but we do need better tracking of our fresh foods.
 

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Can we make a pathogen detector?
« Reply #3 on: 16/06/2011 01:34:56 »

 

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