Ask A Scientist© Molecular Biology Archive

name        Gladys
status      student
age         14

Question -  Can bacteria kill dangerous germs?
 
Your question is not clear: 'dangerous germs' ARE
bacteria. So your question is: can some bacteria
(harmless ones) kill other bacteria that cause disease
(pathogenic bacteria). In theory, yes. Some bacteria
produce substances that are toxic to other bacteria.
However this is never applied to protect food, for
instance. It is also not used as medication.

One way of preventing 'dangerous germs' in our food is
to let harmless bacteria get there first. That is why
yoghurt is longer lasting than fresh milk: the
bacteria that are already present in the yoghurt (and
that produce the taste) prevent other bacteria to
grow. But the yoghurt bacteria don't kill the others.
They just compete with food, and since we put lots in
there, they overrule the odd 'bad one'.

Trudy Wassenaar
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What is needed to answer this question is a definition of the word
"germs." The common definition of "germs" are small things people
cannot see that make them sick. Translating this to scientific
terminology, you are referring to both bacteria and viruses.

So there are two points to make in addressing the question, "Can
bacteria kill germs?"

First, since bacteria is a type of germ, and there are lots and lots of
types of bacteria, the general answer would be bacteria don't kill
themselves.

Second, involves addressing the role of viruses. Viruses tend to use
cells to make thousands and thousands of copies of themselves. They use
both bacterial cells and cells in your body to do this. A virus will
invade a healthy cell, and manipulate it's DNA (or cell programming) to
make more copies of the virus. So, the answer to this part of the
questions is "no" as well.

Bear in mind, that germs are a natural part of our world. They are
everywhere, in the air we breath, on our skin, and in our mouths. Most
of the time there aren't enough of them to make us sick, and our immune
systems can control them.

Saundra Sample
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