Stories tagged E. coli

You'll never guess what's in the can: This isn't Sable Sheets, by the way. Just some other pro-sniffer.
Courtesy Thomas HawkOops. I forgot y’all are too cool to read the word “poopy” now and again. Maybe next time I’ll drop an S-bomb on y’all. Or I could write “sulfurous compounds,” or skatole, or indole. But where would that get us? Nowhere very graphic, certainly.

So, how would you like it if it was your job to sniff out human feces?

Well, I’m sorry, but the job has already been taken. Taken, no less, by a member of a group whose mission in this country seems to be to take jobs from honest, upstanding Americans. That’s right: dogs.

This particular dog is named Sable Sheets, and he hails from Lansing, Michigan. (He doesn’t actually have a last name, being a dog, so I gave him one.) Sable is a professional sniffer of crap. If sniffing human feces were an Olympic sport, Sable would be a gold medalist, if it were a martial art, Sable would be a ninja. It is a serious pursuit—Sable sniffs for the government.

Since he was a puppy, Sable has been trained to recognize certain smells: the odors of water contaminants. Earlier this week, we went over just how great at smelling dogs are. Sable needs to be a great smeller, because not only does he have to recognize chemical contaminants, like those that come from household detergents, but he also has to be able to distinguish animal feces from human feces. A little animal feces in the water is gross, but if Sable can detect human feces it’s a sign that there could be a failed and leaking septic system nearby. Aside from the other obvious issues involved with poop in your water, leaking septic systems can lead to E. coli contaminating rivers and streams. And we don’t want that.

Municipal governments hire Sable and his handler, a former K-9 officer, to check out catch basins, outflows, and manhole covers. If Sable gets a hint of duke, he barks and looks at his handler.

E. coli bacteria can, of course, be detected without the help of a dog, but only with the help of laboratory equipment. To find and test all possible sources of E. coli contamination in a water system would take a tremendous amount of time and effort. A dog like Sable—who, at the moment, might be one of a kind—can speed up the effort greatly. He’s like a miniature, mobile, furry lab. Based on the sample’s that have been sent to the lab on account of Sable’s barks, the dog is about 87 percent accurate.

His handler adds that Sable is “getting better; getting more refined.” Sort of like a connoisseur of fine wines, really, but with… you know.

Tags : dogs, water, health, infectious disease, E. coli, bbbbbbbbbbbbbooooooooorrrrrrrrrrrrrriiiiiiiiiinnnnnnggggggggggg

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For decades, scientists have been growing microbes in their labs and watching them evolve new traits. Most of the changes tend to be simple things, like an increase in size or growth rate.

But Dr. Richard Lenski of Michigan State University (just 2 miles from my house!) recently witnessed a major evolutionary leap--as it was happening. Twenty years ago, he took a colony of E. coli, a common bacteria, and split it into 12 identical populations. He’s been watching ever since to see if the strains evolve in different directions.

A few years ago, one of them did. One of his study strains suddenly evolved the ability to eat citrate, a molecule found in citrus fruits. No other E. coli in the world can do this, not even the other strains in Dr. Lenski’s lab. Even given several extra years and thousands of extra generations, the other strains are still citrate-averse. What’s more, the bacteria evolved this mutation entirely on their own, without any prodding or genetic manipulation from the researchers.

Lenski had saved frozen reference samples of all of his strains at regular intervals. Going back and growing new cultures from these samples, he again finds that only those from one strain ever evolve the citrate-eating habit – and only those sample less than about 10 years old. Lenski figures that some mutation happened around that time in one strain – and one strain only – that would later lead to citrate eating. He and his lab are now working on figuring out exactly what that mutation is.

Tags : evolution, bacteria, E. coli, adaptation, heredity, genetics

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Transmission electron micrograph of Escherichia coli O157:H7: Courtesy CDC A recent NY times article looks into various approaches underdevelopment to prevent or treat food poisoning by the bacteria E. coli O157:H7. These approaches include:
Prevention – as we saw last fall, this does not always work. This is especially true with fresh produce.
Cattle vaccines – it reduces but does not eliminate the E. coli found in manure. Would this give us a false sense of security? What would the incentive be for farmers to vaccinate their herds? Cows don’t get sick from the bacteria so it would have to be a mandate or altruism.
Cattle antibiotics – feeding antibiotics to cows raises concerns of creating more antibiotic resistant pathogens.
Industrial chemicals – feed cows sodium chlorate which the O157 bacteria converts to it to sodium chlorite which poisons the pathogen
Bacterial-killing viruses – these are viruses that infect and kill only bacteria.
Friendly bacteria – is also known as probiotics. This approach feeds cattle friendly bacteria to displace the O157 bacteria. It is already sold to aid cattle digestion and some believe it reduces the amount of O157 bacteria in the manure
Human vaccines – are still years from the market. Early testing looks promising. Testing the effectiveness will be difficult. Should we be vaccinating every child in order to protect a small number? And would this make us lax with our food handling techniques. That will lead to other food and water borne infections.
Human drugs for treatment – outbreaks are rare and sporadic so these would be hard to test in clinical trials. The clues that signal an infection don’t start until 3-4 days after ingestion of the bacteria so it might also be hard to diagnose and treat the infection in a timely manner.
Monoclonal antibodies – these are a synthetic version of your body’s own infection fighters. They seem to be working in animals and with early human safety trials. But the cost is prohibitive to test them in order to prevent hemolytic uremic syndrome. This would start working once the toxin is already in the bloodstream so there are questions about its effectiveness.

We will probably see a few of these techniques used in parallel. What do you think is the best approach and why?

Tags : bacteria, health, E. coli, cattle, germs, food poisoning

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The Minnesota Department of Health is investigating seven suspected cases of E. coli infection linked to Taco John's restaurants in Albert Lea and Austin. Almost three dozen people in Iowa came down with suspected E. coli infections after eating at a Taco Johns in Cedar Falls.

There's no indication that these infections are linked to the E. coli outbreak (64 cases) related to Taco Bell restaurants in the Northeast, but the Centers for Disease control haven't ruled a connection out, either.

Investigators initially thought contaminated green onions were the source of the infections, but follow-up testing on the samples was negative for E. coli. So we still don't know what the contaminated food was. But fresh produce is a likely culprit.

Bagged lettuce: Packaged produce, like this lettuce, makes it easier for us to consume the recommended daily servings of fruits and vegetables. But packaged, fresh produce is increasingly linked to outbreaks of food-borne illness. (Photo courtesy Michael Dietsch)

And it's hardly the first time fresh produce has been implicated in outbreaks of food-borne disease. These latest cases follow hard on the heels of salmonella cases linked to tomatoes, and the nationwide E. coli outbreak linked to bagged spinach. (All in the last three months!)

According to the Washington Post,

"The number of produce-related outbreaks of food-borne illness has increased from 40 in 1999 to 86 in 2004, according to the Center for Science in the Public Interest. Americans are now more likely to get sick from eating contaminated produce than from any other food item, the center said."

Why the increase?
Well, more people are eating fresh produce, especially pre-cut and packaged fruits and vegetables. Distribution has improved, as has electronic reporting of outbreaks. And the aging population of the US is more susceptible to food-borne disease. And produce is a particularly difficult challenge: with contaminated meat, cooking to the proper temperature will kill the bacteria that cause disease. (Food safety experts call this a "kill step.") But produce is often meant to be eaten raw—no kill step.

(For more on the SOURCES of E. coli in fresh produce, see the thread on the September spinach outbreak.)

So what do we do?
Again, according to the Washington Post,

"Consumer advocates think that tougher mandatory food safety standards and stepped-up enforcement are the answer. The country's largest food distributors and restaurants are pursuing self-regulation, arguing that government rules can take years to put in place. Produce growers and packers have suggested a voluntary system with elements of mandatory oversight."

But none of these are ready to be implemented right away.

Some folks are advocating for better and more frequent inspection of processing plants by the Food and Drug Administration (FDA), but the agency is chronically short-staffed and underfunded. And the FDA doesn't have authority over food production at the farm level. Buyers such as Safeway and Albertsons have hired their own inspectors. But inspectors and food safety experts agree that there's no consistency because federal guidelines aren't specific enough.

The article says,

"'We don't have enough science to base those (guidelines) on to be comprehensive," said Kevin Reilly, a California food safety official who is participating in the investigation of the E. coli outbreak traced to bagged spinach. 'What's necessary is an agreed-upon set of agricultural practices. Instead of "Be aware of water quality," we need to say, "Test it with this frequency and in this fashion."'"

In the meantime, scientists are looking at various ways to kill potential contaminants without ruining the produce or having to cook it.

Unless something changes, there WILL be another outbreak.

My $0.02? I don't want to read any more stories about children or grandparents having kidney failure or even dying from E. coli infection. So I guess I'm all for killing off the bacteria, if we can. But part of me thinks, yes, I want safe food, but I also want CLEAN food. Even if eating poop can be made safe, I still don't want to eat poop!

What do you think? Do you worry about food safety? Do you rely on pre-cut and or packaged fruits and vegetables? What safety measures would you like to see? Any ideas about how we can improve the situation?

Tags : spinach, E. coli, tomatoes, 0157:H7, green onions, food safety, food

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