Friday, May 18, 2007
Washing off the E. Coli not so easy
As part of my investigation of food safety for this weekend's special, I really wanted to look into this whole idea of "triple washing" spinach. What does that really mean and is it effective? In order to best investigate this, we decided to do our own independent scientific testing. We actually took some E. coli 0157:h7 (the bad stuff) and placed it on a few spinach leaves.

Now, keep in mind, it takes only about 100 organisms to make you sick, even fewer if you're young, old or already ill. We took carefully measured samples of spinach leaves, "inoculated" them with E. coli 0157 and then tried to wash off the dangerous bacteria. Not washing the spinach at all left around 12,000 bacterial colonies, which could include as many as 24,000 microorganisms. (Watch: We test different washing techniques against E. Coli)

Now, with tap water, which is what most people probably use, the number of organisms was reduced to about 3,700. A vigorous wash with tap water left 2,900.

The commercial wash left around 6,000 organisms, even worse than tap water alone.

Chlorine plus the commercial wash left around 2,300.

But remember, any of these amounts will make you sick.

So, clearly washing the produce alone at home isn't enough, and the commercial washes during the packaging don't seem to be adequate either. In my CNN Special Investigations Unit Danger: Poisoned Food hour this weekend (8 p.m. and 11 p.m. ET Saturday and Sunday), you will see that we came up some other alternatives. But, I am eager to hear what you do to clean your fruits and vegetables. What do you think would work to make our produce safer?

Editor's Note: Please include your name, city and state when responding.
Hi Dr. Gupta,
Clorine? That's poison! AND I don't even drink or cook with tap water! I have been cooking my spinach but I do like it raw.
OK~ Dr. Gupta. If you don't know how to make our produce safe then I give up!
I guess I will either cook it or just take my chances! I was counting on those companies who package veggies to keep it clean. I guess I will have to watch your special program to find out how to eat healthy and not get sick!
Thanks! You always have fasinating reports!
I currently just use tap water to rinse off fruit and vegetables, knowing that if they are tainted it really won't help. I believe that to make our food safer and healthier we need to start eliminating factory farms, which produce meat with hormones and antibiotics, and poison the surrounding environment. Vegetables should not be grown anywhere where they can be exposed to the toxic waste from factory farms.
I find that the most effective/safe way to wash fruits/vegetables is to use a small amount of detergent and warm water. Gently scrub them as if you are washing your hands. Switch to cold water. You can wash lettuce leaves using this method too!
Apple cider vinegar, made from apples, and garlic kills E.coli. Other spices/herbs kill bacteria as well.

I use apple cider vinegar 50% with water to spray my cutting board, sink, counters instead of bleach,
and to mix with oil for salad dressing, with garlic and spices. No need to feel so fearful to eat veggies,
if you research the function of spices and herbs on the web.

Apple cider vinegar, from apples, not grain, has health benefits---much more than a weight-loss fad.
We also use vinegar, first soaking the fruits and vegetables in it and then rinsing well. It would be interesting to found out if it actually does eliminate any of the E coli but it makes us feel better knowing we are doing something.

There is an inherent problem with the mass production of food and the public is depending on the FDA to protect them from any unsafe practices in our country. This also leads to to the issue of imported food and how much of that is actually being inspected.

If the FDA is relying on illness as a monitoring tool, the milder cases of food poisoning are probably under reported as they can be mistaken for a viral gastrointestinal illness.

When I go food shopping for my family it is always in the back of my mind, is this food safe? What a horrible thing for a parent to have to wonder about.

Maybe there should be an online rating for all food companies and their safety records. Pay for performance. It would be good incentive for companies if they realize their bottom line will be affected.
In addition to the comments and suggestions already posted, here are two more things that I do:

1) For eating raw, I try to buy fruits and vegetables that were grown by producers I'm familiar with. My food co-op (PCC) is very choosy about its producers and keeps an eye on the conditions under which the food is grown. These producers are careful about their methods.

2) I keep my digestive system healthy and well-colonized with healthy bacteria. I'm a vegetarian and I consume a lot of fiber, which binds toxins and helps move them out of the body. I regularly use a good-quality probiotic supplement. This way, even if I do end up eating something that's contaminated, I'm starting from a position of strength.

Marion Kee, Redmond, WA
I have sent the following to CNN, NY Times, Washington Post as well as the FDA. Perhaps you, who represent victims and families that have had a loss because of the e-coli problems here in California, can get the proper agencies or journalists to look into this. This is a big cover-up by the biotechnology agency as well as the EPA and FDA. 2/3 of your biotechnology companies are here in the state of California.

EVERYONE should know that while organic sounds "risk free" it is NOT. People are concerned about chemicals being used for pesticides. When chemicals are not used for pesticides the term "organic/natural" is applicable. "Organic/natural" also includes microorganisms "bacteria and fungus" as they are naturally found in soil, plants ect. This has lead to the discovery, development and use of biopesticides (biological). These microorganisms are even mutated by biopesticide companies. Some of these microorganisms are being brought into the US from other countries. (Why are we inoculated when we visit other countries? Because we don't have an immunity to other countries microorganisms)

These biopesticides end up being used on our food crops which in turn we eat, not to mention we eat the livestock that is also subjected to biopesticides being used on their food.

"GM Microbes Invade North America" ie; biopesticides (found on states: "GM microbes have begun to be ubiquitous invaders of the North America ecosystem. This massive invasion took place with little or no public awareness and input, and with very little monitory of the impact of the invasion. The environmental risk assessments of the commercial microbes were rudimentary and frequently erroneous. We may have a bio-weapons equivalent of a time bomb on our hands."

Are biopesticides involved with the recent spinach and e- coli problem? I believe the answer could be YES. It is said this recent e-coli has a different DNA and is "more potent". Possible reason for my theory:


Simultaneous production of biopesticide and alkaline proteases by Bacillus thuringiensis using sewage sludge as a raw material.

* Tyagi RD,
* Sikati Foko V,
* Barnabe S,
* Vidyarthi AS,
* Valero JR,
* Surampalli RY.

INRS-Eau, 2700 rue Einstein, Sainte-Foy, Quebec, Canada G1 V 4C7.

The simultaneous production of Bacillus thuringiensis (Bt) based biopesticide and proteases was studied using synthetic medium and wastewater sludge as a raw material. The studies were conducted in shake flask and computer controlled 15-L capacity fermentors. Measuring viable cell and spore counts, entomotoxicity and protease activity monitored the progress of the biopesticide production process. A higher viable cell count and spore count was observed in synthetic Soya medium, however, higher entomotoxicity and protease activity were observed in wastewater sludge medium. Thus, the wastewater sludge is a better raw material than commercial Soya medium for the biopesticides and enzyme production. The maximum entomotoxicity and protease activity observed in the fermentor was 9,332 IU/microL and 4.58 IU/mL, respectively. The proteases produced by Bt were also characterised. Two types of proteases were detected; neutral proteases with pH optimum 7.0 and alkaline proteases with pH optimum 10-11. Further, two types of alkaline proteases were detected; one having a pH and temperature optimum at 10 and 50 degrees C while the other at 11 and 70 degrees C. The protease thermal stability was found to increase in the presence of CaCl2, indicating the proteases were metalloproteases.

PMID: 12479478 [PubMed - indexed for MEDLINE

I don't buy the explanation that livestock was too close to crops. Livestock has existed close to crops for centuries.

I have contacted the proper authorities on the e-coli and spinach problem to no avail.

The public is NOT being told the truth.
I was hoping to get to Dr. Gupta, but I'll use this for our question.

We watched the show the other night on E. Coli, and my wife posed a couple of questions.

We have been using cow manure, along with many other animal and human excrement, for centuries. Why all of a sudden do we have this problem with E. Coli? I'm sure it's a mutant of some sort since other forms of E. Coli seem to proliferate in the world, but what happened to bring on this form?

Secondly, and since Dr. Gupta is Indian, with all the cattle in India, and what appear to be questionable hygiene practices in at least some areas of the country, why have we not heard about E. Coli deaths in India?

We enjoy the Doctor's insight and knowledge in many areas.
Dr. Gupta, you usually do amazing work and I applaud you for taking on the food safety issue. I'm concerned however that one thing not being addressed is the loss of funding the FDA and the state and local health departments have suffered, funding that would have enabled them to staff up and do more comprehensive monitoring as well as problem solving related to the foodborne illness outbreaks. Also, please factor in that over the years, these outbreaks likely have been occurring under the radar due to unsophisticated lab tests. More fruits and vegetables are being eaten, our food production system has changed, lab tests are more exact and can be turned around more rapidly. In all fairness, this may not be as new a problem as its being made out to be. With funding cuts, how can the FDA be expected to keep up? Some of the problems lie squarely in the lap of the politicos who cut the funding. Diarrhea and vomiting are not sexy political issues. And as an aside, please oh please, do not let Lou Dobbs work on the food safety issue. I will change news stations if he does so.
i am a huge fan of the dr., and i wonder if fresh spinach cannot be trusted, what about canned or frozen spinach. haven't heard him speak of that
i'm happy to know about apple cider vinegar. thank you. i'm also wondering about frozen spinach.
I usually like this column, but I don't like the fact you leave us hanging instead of telling us the alternatives you found. Oh, go watch the CNN special...thanks but I don't have cable! Guess I'll have to hope you'll tell us once the show is over.
It's things like this that make me glad I have family members with their own vegetable gardens.
I tend to wash my fruits and vegetables with a solution of baking soda and water, usually a table spoon of soda/spray bottle. Letting the solution sit on the food for at least a minute helps ensure its efficacy. It also doesn't impart a scented flavor to any of them. Just make sure you rinse.
E Coil comes from the intestinal tracks of COWS. Cow manure is spread in massive amounts on fields and contaminate VEGETABLES.

Want to see what HELL looks like? Visit this Factory Farm page and see where the E Coli comes from. We live in HELL in Eden NY, the Garden Spot of NY State and home of fresh produce sold all over Western NY. Would YOU eat anything grown in THESE fields?
Dr. Gupta,

After watching your investigative report on E. coli we feel it is our responsibility to work harder to get the word out about a sanitizer for produce that we handle. This sanitizer called "Pro-San" was developed for NASA's Space Station and has recently been released for the public.
Our product has already been tested with Ecoli 0157:H7 on apples and lettuce and has proved very effective. Please see the efficacy of chemical treatments for inactivating escherichia coli 0157:H7 on whole apples and lettuce. Now, as per A.F. Mendonca, and T.L. Traynham, NASA Food Technology Commercial
Space Center, Department of Food Science & Human Nutrition, Iowaq State University, 2901 South Loop Drive, Suite 3700, Ames, Iowa 50011.
Currnt practice of washing fresh produce in chlorinated water producesa only minimal reductions in microbial numbers that range from approximately 10 to 100-fold (1 to 2 logs). Studies were conducted to determine the antimicrobial efficacy of selected chemical sanitizers for destroying or substantially reducing Escherichia coli 0157:H7 on whole apples and lettuce leaves. Red delicious apples and leaves of iceberg lettuce were spot-inoculated with E. coli 0157:H7 B914, air-dried in a laminar flow hood at room temperature (23 C) for 1 hour, then held overnight at 4 C until application of sanitizer treatments. Inoculated apples and lettuce were immersed for 2 minutes in distilled water or the following sanitizers at 25 C:200 ppm hypochlorite, hydrogen peroxide (H2O2,5% wt/vol), sodium hydroxide/bicarbonate buffer (NaOH-NaHCO3; PH 11.6) Tsunami 100 (80 ppm), and Pro-San (2% wt/vol). Inoculated samples which were not immersed in water of sanitizer served as no-wash controls. Following each treatment samples were rinsed for 5 seconds in sterile distilled water. After rinsing, samples were placed in separate plastic bags each containing 50 ml of sterile buffered peptone water (BPW) and vigorously shaken and rubbed to dislodge surviving cells into the BPW. Microbiological analyses were conducted on the BPW to determine the number of E.coli 0157:H7 survivors. Numbers of E.coli 0157:H7 on no-wash controls were 6.42 logs and 6.36 logs, respectively, per apple and lettuce leaf. The water-wash, which reduced numbers of E.coli 0157:H7 on apples and lettuce by 1.43 logs and 1.20 logs, respectively, was the least effective of all the treatments. Except for the hypochlorite treatment, all sanitizers tested resulted in log reductions ranging from 2.84 to 3.27 logs for apples and from 2.36 to 3.08 logs for lettuce. These reductions are significant with respect to the numbers of pathogenic bacteria that may occur on fresh produce. Hypochlorite (200 ppm) reduced numbers of E. coli 0157:H7 on apples and lettuce by 1.65 logs and 1.28 logs,respectively. However, the antimicrobial effect of this treatment differed significantly from that of the most effecftive treatments which were H2O2 (5%) and Pro-San (2%). H2O2 or Pro-San, a biodegradable foodgrade sanitizer, seems to have good potential for destroying foodborne pathogenic bacteria on whole apples and lettue. The development of novel, effective food grade sanitizers is crucial for ensuring the miccrobial safety of fresh fruits and vegetables for astronauts in space as well as for consumers on earth.
Do you think you can contact us to help us get the information and samples of "Pro-San" to the right people?

Thank you,

Joseph A. Leon
Native International Distributors
1001 H Street
Bakersfield, CA 93304
I work in the produce industry. As soon as the main implicated packer of organic spinach heard of a possible infection, they tripled their effort cleaning the plant. No nook and cranny was untouched. To hear them explain it, they did it out of concern and care they take in producing healthy food. The real reason is, they dreaded an inspection from the FDA. In turn, the FDA was complicit by waiting until they were given a green light for an "inspection". It's a farce.
As far as food safety is concerned why do you not include personal responsibility of washing and cooking the food. Mothers in this country do not want to spend time in the kitchen. If you have bad eating habits and eat raw stuff you will have infections, what is so complicated about that. Stop eating like cavemen and learn from eastern cultures how to cook - it is a reflection of civilisation.
About 6 weeks ago my daughter was diagnosed with HUS. I had hear of ecoli, but not about HUS. No one near us was identified as having ecoli but I suspect most of the kids were thought to have a simple stomach/intestinal virus. After hear of the story about Ashley in the report I know we dodged a bullet. Please do more stories, to get the information out there.

I lived in Africa and I ate contaminated lettuce every day! I also drank contaminated water! All I did was soak my lettuce in water (contaminated!!) with a few drops of iodine in the sink-full of water!!! You have to soak it for about 1/2 hour in cold water with a few drops of iodine and it soaks in all the way into the veins of the lettuce! Americans need more iodine anyway!!! The Japanese get 100X more iodine than we do! Heard about that brown algae fat loss miracle? IODINE!!!
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