Antibiotics

Antibiotic is a type of drug produced by tiny plants called
microorganism. Most of the microorganism that produce
medically useful antibiotic are molds and bacteria that
live in the soil. Antibiotics are sometimes called wonder
drugs or miracle drugs because of their wonderful power to
destroy disease germs quickly, or to stop germs from
growing. 
Antibiotics rank among the most important of all life
saving drugs today. They serve as the doctor's best weapons
against pneumonia, typhoid fever, tuberculosis, syphilis,
scarlet fever, bone infections, dysentery, and many other
serious diseases. 
Hundreds of different antibiotics have been discovered, but
most of them have proved unsuitable for medical use. Some
antibiotics are not active enough against disease germs.
Some work well in test types, but quit working when taken
into the human body. Most of them are toxic (poisonous) to
the human body when taken internally. Important antibiotics
which have been found medically useful are: penicillin;,
streptomycin, erythromycin, and polymyxin. 
At first, only small amounts of antibiotics could be
produced at one time. But, within a few years, scientists
and engineers learned how to produce these life-saving
drugs in huge amounts. Today, many large factories are used
for the manufacture of antibiotics, both in the United States and in many foreign countries. The molds or bacteria
are grown free of all other microorganisms in large closed
tanks, ranging in size from 5000 to 30,000 gallons
capacity. Sterile (germ free) air is forced into the tanks,
or fermenters. It seldom takes more than three days to
complete a fermentation. Once the fermentation is complete,
the antibiotic is concentrated and purified. It is
carefully tested for sterility, purity, and nontoxicity, to
make sure it meets standards set by the Antibiotics
Division of the Federal Food and Drug Administration. 
The production of antibiotics is a very large business in
the United States. Mass production has reduced the cost of
antibiotics.