IT’S A
SMALL, SMALL WORLD:
GOOD GERMS AND BAD GERMS
You might remember a news story about a young lady in Georgia who was suffering through an attack by
a “flesh-eating” microbe. NBC called it a flesh-eating virus. CNN covered the
same story but called it a flesh-eating bacteria. I couldn’t remember exactly
what the difference was between a virus and a bacteria, but I knew it was
something. A friend said, “Oh no, the two are the same. When people get sick
they take antibiotics, that’s all.” Not satisfied, I did some research (by the
way, CNN was right, it was a bacterial infection).
A virus and a bacterium
are two very different things. It’s true that both are microscopic, can infect
a body, and can cause disease; and infections from both can have similar
symptoms. But otherwise they are completely unlike each other
.
BACTERIA
Bacteria are fairly
complex one-celled living organisms that exist almost everywhere in the world,
from the polar ice caps to the deepest oceans. Fossil records have confirmed
that bacteria were present on the Earth 3.5 billion years ago.
They are small, but giant
compared to a virus. If you were a virus and you stood next to a single
bacterium cell, it would be larger than a largest dinosaur. All bacteria have a
cell wall, a nucleus, cytoplasm, all the genetic information necessary to
reproduce, as well as hundreds of inherited traits. All of these things we have
in common with bacteria. They exist inside us, on us, and around us. Each human
has ten times more bacteria cells within their bodies than their own human
cells.
More
than 99% of all bacteria are harmless. Many are hugely
beneficial such as probiotics. Bacteria in humans can prevent infections and
produce compounds that our bodies need, like vitamin K. The Lactobacilli
acidophilus bacteria in our intestines help us digest food. Other bacterial
species fight off disease-carrying microbes and cancer cells. And of course
bacteria assist in the production of cheese, yogurt, pickles, sour cream,
bread, sauerkraut, wine, beer, and even chocolate.
The
less than 1% that are virulent can be deadly however.
Bacteria can cause diseases like cholera, typhoid fever, tuberculosis,
botulism, gonorrhea, leprosy, E. coli infection, tetanus, Bubonic Plague,
whooping cough, anthrax, salmonella, and Aeromonas hydrophila (that’s the
flesh-eating bacteria). But on the whole, they do more good than bad. Really.
If you have followed the
“Ted Talks” series on the Science Channel, you might be aware that new research
indicates that bacteria actually communicate with each other, have a surprising
level of social organization, and work as a group. They can even organize
themselves to launch an attack on higher life forms.
VIRUSES
Viruses on the other hand
are from the dark, dark place. They are not considered to be LIVING organisms
but tiny structures with limited genetic material wrapped in a protein shell.
They have no internal metabolism, meaning they cannot collect or use energy;
and they have no ability to keep conditions inside their shells stable (called
homeostasis) as living organisms can.
A virus cannot reproduce
on its own. It must exist inside a living host in order to replicate. It
attaches itself to a cell and takes over the host’s cellular machinery. Viruses
reprogram the cell to make new viruses, or turn normal cells into malignant,
cancerous cells.
Virtually
all viruses cause disease. Certain viruses attack cells in
specific human structures like the blood, liver, or the respiratory system.
Viruses cause such common diseases as smallpox, flu, HIV and AIDS, polio,
measles, hepatitis, mumps, rabies, chickenpox, Ebola virus, Yellow Fever,
herpes . . . and the common cold. The
only possible benefit that viruses could have is that some of them target
bacteria. If they could be programmed to attack the dangerous bacteria strains,
we may have a new weapon, but that’s not possible at this time.
During the past century,
some progress has been made to reduce the damage that bacteria and viruses
cause. Antibiotics for bacterial
infections and vaccines for viral
infections have been produced. Polio, measles, and some flu strains have
been largely contained. Unfortunately, we have reached a point where over-used
antibiotics combined with bacteria’s genetic adaptability, have made the drugs
unreliable. Vaccines as well are becoming less effective in treating viruses
due to drug-resistance.
The next time you have a
wine and cheese party, give thanks to bacteria; but the next time you get the
flu, remember - you could have gotten that flu shot.
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