E.coli [Escherichia coli] Science
Country: United States
Date: December 2004
What treatments or detectors are there for ecoli today?
First of all, E. coli is a diverse species, just like Canis familiaris (the
dog). There are many different strains of E. coli. There are some that are
like pit bulls-mean and nasty and can make you very sick. Most are like
golden retrievers-laid back and friendly. The reason they get their name (coli)
is because they are found in the colon, or intestines. In fact, we can't
live without them! They help us digest our food and actually make vitamins for
us that we have come to depend on. So, why all the hype about it lately?
Because there is a particularly nasty strain called E. coli O157:H7 that
causes food poisoning. Food poisoning is where you get sick from a toxin that the
organism gives off rather than from the organism itself. The typical
scenario is that cattle live outside and gets fecal matter on its hide. Then when
it is slaughtered, some of that fecal matter can get on the meat by accident.
This is not a problem usually if we are talking about steak or other single
cuts of meat. Because this bacteria is easily killed by cooking. But
hamburger or other ground meat is usually made by grinding a bunch of different
cuts together and bacteria could be on the inside. If the hamburger is not
cooked all the way through (pink in the middle) then the bacteria might not be
killed. And if you eat it, you can get sick. There have also been cases of
this food poisoning in fresh fruits and vegetables where the fields have been
watered with water that is contaminated with human or animal waste.
So to your question-it is very difficult to practically test for this (or
any) organism. It takes as little as 10 bacteria to make you sick and since
they are microscopic it would be difficult to test every cut of meat for it.
Meat is regularly inspected, but they can't test every piece of meat. The
best way is to maintain sanitary conditions at the packing plant. City water
departments regularly test the water for contamination before they release the
water for drinking and they use chlorine to sanitize the water. The best way
to be as safe as you can is to make sure you cook your food thoroughly.
E. coli is still identified by classical plating out on differential media
and microscopic observation. In addition there are some more modern methods
which detect DNA sequences specific for this organism. There are many antibiotics
that can be tried but often times the particular strain of E. coli may be resistant
to many of these antibiotics.
Ron Baker, Ph.D.
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Update: June 2012