The Benefits of Antibiotics
Antibiotics are among the most prescribed medications in modern medicine.
Antibiotics cure disease by killing or injuring bacteria. The antibiotic was
penicillin, discovered accidentally from a mold
culture. Today, over 100 different antibiotics
are available to doctors to cure minor
discomforts as well as life-threatening
infections.
Although antibiotics are useful in a wide variety of infections, it is important
to realize that antibiotics only treat bacterial infections. Antibiotics are useless
against viral infections (for example, the common cold) and fungal infections (such
as ringworm).1
The history of antibiotics -- for centuries preparations derived from living
matter were applied to wounds to destroy infection, the fact that a microorganism in
capable of destroying one of another species was not established until the later part
of the 19th century.
When Pasteur noted the antagonistic effect of other bacteria on the anthrax
organism and pointed out that this action might be put to therapeutic use.
Meanwhile, the German Scientist chemist Paul Ehrlich developed the idea of
1
www.emedicinehealth.com/antibiotics/article_em.htm
1|Page
selective toxicity: that certain chemicals that
would be toxic to some organisms, e.g.,
infectious bacteria, would be harmless to other
organisms, e.g., humans.2
3
In 1928, Sir Alexander Fleming (1881-
1955), a Scottish biologist, observed that Penicillium notatum, a common mold, had
destroyed staphylococcus bacteria in a culture, and in 1939 the American
microbiologist Rene Dubos demonstrated that a soul bacterium was capable of
decomposing the starchlike capsule of the pneumococcus bacterium, without which
the pnenumococcus is harmless and does not cause pneumonia. Dubos then found
in the soil a microbe, Bacillus brevis, from which he obtained a product, tyrothricin
that was highly toxic to a wide range of bacteria.
Tyrothricin, a mixture of the two peptides gramicidin and tryrocidine, was
also found to be toxic to red blood and reproductive cells in humans but could be
used to good effect when applied as an ointment on the
body surfaces. Penicillin was finally isolated in 1939, and
in 1944 Selman Waksman and Albert Schatz4, American
microbiologists, isolated streptomycin and a number of
2
www.infoplease.com/ce6/sci/A0856640.html
3
Sir Alexander Fleming, (Google images)
4
Selman Waksman and Albert Schatz, (Google images)
2|Page
other antibiotics from Streptomyces griseus.
Types of Antibiotics -- Although there are well over 100 antibiotics, the
majority come from only a few types of drugs. These are the main classes of
antibiotics.
 Penicillin such as penicillin and amoxicillin
 Cephalosproins such as cephalexin (Keflex)
 Macrolides such as erythromycin (E-Mycin),
clarithromycin (Blaxin), and azithromycin (Zithromax)
 Fluoroquinolones such as ciprofloxacin (Cipro),
levofloxacin (Levaquin), and ofloxacin (Floxin)
 Sulfonamides such as tetracycline (Sumycin, Panmycin)
and doxycycline (Vibramycin)
 Aminoglycosides such as gentamicin (Garamycin) and
tobramycin (Tobrex)5
Most antibiotics have 2 names, the trade or brand name, created by the drug
company that manufactures the drug, and a generic name, based on the antibiotic
chemical structure or chemical class. Trade names such as Keflex and Zithromax
are capitalized. Generics such as cephalexin and azithromycin are not capitalized.6
5
www.emedicinehealth.com/antibiotics/page2_em.html
6
www.emedicinehealth.com/antibiotics/page2_em.html
3|Page
Production of Antibiotics – The mass
production of antibiotics began during World
War II (1939-1945) with streptomycin and
penicillin. Now most antibiotics are produced by
staged fermentations in which strains of
microorganisms produce high yields grown under
optimum conditions in nutrient media in fermentation tanks holding several
thousand gallons of the microorganisms. The mold is strained out of the
fermentation broth, and then the antibiotic is removed from the broth by filtration,
precipitation, and other separation methods.7
In some cases new antibiotics are laboratory synthesized, while many
antibiotics are produced by chemically modifying natural substances; many such
derivatives are more effective than the natural substances against infecting
organisms or are better absorbed by the body, e.g., some semisynthetic penicillin’s
are effective against bacteria resistant to the parent substance.8
Current issues in Medicine and Antibiotics – One of the foremost
concerns in modern medicine are antibiotic resistance. Simply put, if an antibiotic
is used long enough, bacteria will emerge that can’t be killed by that antibiotic.
This is known as antibiotic resistance. Infections exist today that are caused by
7
From Cowpox to Antibiotics: Discovering Vaccines and Medicines. Carol Ballard. Chicago, Illinois: Heinemann
Library, a division of Reed Elsevier Inc; 2006
8
www.infoplease.com/ce6/sci/A0856639.html
4|Page
bacteria resistant to some antibiotics. The existence of antibiotic-resistant bacteria
creates the danger of life-threatening infections that don’t respond to antibiotics.
There are several reasons for the development of antibiotic-resistant bacteria.
One of the most important is antibiotic overuse. This includes the common practice
of prescribing antibiotics for the common cold or flu. Even though antibiotics don’t
affect, many people expect to get a prescription for antibiotics when they visit the
doctor. Although the common cold is uncomfortable, antibiotics don’t cure it, nor
change its course. Each person can help reduce the development of resistant
bacteria by not asking for antibiotics for a common cold or flu.
9
In Sir Alexander Flemings Nobel Prize lecture (December 11, 1945) -- “…We
are not at the end of the Penicillin story. Perhaps we are just only at the beginning.
We are in a chemical age and penicillin may be changed by chemists so that all its
disadvantages may be removed and a newer and better derivative may be
produced…”10
9
www.emedicinehealth.com/antibiotics/page7_em.html
10
www.nobelprize.org/nobel_prizes/medicine/laureates/.../fleming-lecture.pdf
5|Page
Works Cited and Bibliography
Sir Alexander Flemings Noble Prize Lecture December 11, 1945. Penicillin
www.nobelprize.org/nobel_prizes/medicine/laureates/.../fleming-lecture.pdf
Antibioticswww.emedicinehealth.com/antibiotics/article_em.html
History of Antibioticswww.infoplease.com/ce6/sci/A0856640.html
From Cowpox to Antibiotics: Discovering Vaccines and Medicines. Carol Ballard. Chicago, Illinois:
Heinemann Library, a division of Reed Elsevier Inc; 2006
6|Page