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Fleming was
certainly very fortunate to have just accidentally discovered
this antibiotic. He was famous for being untidy, especially in
his laboratory, or as he would put it, he preferred to have
his cultures and equipment ready at hand. Another one of his
habits was to leave his glass dishes lying around for a week
or so, since he wanted to see if there were any note-worthy
changes. It was on one such occasion when he was working on 'staphylococcus',
a bacteria that causes abscesses and infectious skin boils,
that he left a culture of staphylococci growing on his plates,
in the laboratory. |
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Dr. Fleming |
Some days later, he
saw a green mould growing on the plate. All the bacteria that had
previously been there had got dissolved and wherever the culture had
come in contact with the mold, there were defined rings in that
position. Fleming went on to test the mould and found that the green
flecks had similar characteristics to the mould of the genus,
Penicillium, Penicillium notatum, which Fleming
later shortened to 'penicillin.' His tests showed that the mould
released a bacteria-killing substance in the form of tiny
golden droplets. This liquid was as good as killing the
bacteria as the mould itself. He determined that penicillin was a
simple fungus, much like the mould found on cheese or bread but with
deadly qualities.
As early as
1877, Louis Pasteur had discovered this kind of antibiotic
action and many moulds and fungi were being use to cure infections,
however Fleming was the first to actually define and name this
substance 'penicillin.' But he was unable to extract the active
agent.
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It was only
years later that reputed people such as Dr. Howard
Florey and Dr. Ernst Chain, set out to isolate and
test a sample of pure penicillin. In late 1939, they were
successful in creating the antibiotic in the form of a
yellow powder. The tests showed that the powder
retained its effectiveness even after being diluted 30
million times and was more powerful than sulfa drugs
which were used to treat diseases like strep throat, spinal
meningitis, gonorrhea etc.! The unique quality about
penicillin is that as harmful it may be to bacteria cells, it
is just as harmless to living/human cells. |
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Dr. Florey |
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Working with
Fleming, Florey and Chain were able to create a more potent
sample and later began putting their 'miracle'
to good use. It was used to cure many people but the long and
difficult procedure of creating it, hindered its availability.
After trying to get help from many places but in vain, Florey
traveled to United States of America in 1941
to seek assistance. He was granted help and penicillin was
declared a high priority war product during
1941 war. |
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Dr. Chain |
Struggling through a
lot of hardships and disappointments, production of penicillin
reached such heights within a year that there was sufficient amounts
to treat 7 million patients a year! Penicillin
showed remarkable cure rates in people suffering from
pneumonia, scarlet fever, strep throat, diphtheria, syphilis and was
effective in blood poisoning, gas gangrene, and some forms of
endocarditis and meningitis cases.
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2. Mucoprotein building blocks
(blue) make up the cell wall of
a healthy bacterium; the cell can
only function normally if this wall
continually expands. |
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1. The 3 basic parts of all
bacteria are the wall (pink),
the cytoplasm (orange) and
membrane (blue). Antibiotics
have only to disrupt one of
the life processes to kill
them. Penicillin destroys
the expansion of the cell
wall of some kinds of
bacteria. |
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3. When a new wall has to be made,
part of the old one dissolves. The
transport enzymes (golden) then
attach themselves to the mucoprotein
molecules and take them to the
receptor sites, so that they can form
the new wall. The mucoprotein and
sites are designed to fit in perfectly,
like a jigsaw puzzle. |
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4. But when penicillin is present,
the transport enzymes pick up the
penicillin instead of the muco-
protein. Although these
penicillin molecules fit into the
enzyme, the same does not
happen with the receptor sites.
The weak cell wall cannot survive
for long; it breaks, spilling out
cytoplasm and soon the cell dies. |
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The antibiotic did
prove to be imperfect as time went by and people reverted back to
working with the existing drugs. Even today, it is not the best
medicine but it certainly was a blessing to people
in the 1940-50s. Alexander Fleming earned the status of knight in
1944, and he, Fleming and Chain were awarded the Nobel Prize
for Medicine in 1945. They will always be remembered for
their ingenuity and courage to fulfill their ambitions.
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