An
antimicrobial is a
substance that kills or inhibits
the growth of microorganisms
such as bacteria, fungi, or
protozoans, as well as
destroying viruses.
Antimicrobial drugs either kill
microbes (microbicidal) or
prevent the growth of microbes (microbistatic).
Disinfectants are antimicrobial
substances used on non-living
objects.
The history of
antimicrobials begins with the
observations of Pasteur and
Joubert, who discovered that one
type of bacteria could prevent
the growth of another. They did
not know at that time that the
reason one bacterium failed to
grow was that the other
bacterium was producing an
antibiotic. Technically,
antibiotics are only those
substances that are produced by
one microorganism that kill, or
prevent the growth, of another
microorganism. Of course, in
today's common usage, the term
antibiotic is used to refer to
almost any drug that cures a
bacterial infection.
Antimicrobials include not just
antibiotics, but synthetically
formed compounds as well.
The discovery of
antimicrobials like penicillin
and tetracycline paved the way
for better health for millions
around the world. Before 1941,
the year penicillin was
discovered, no true cure for
gonorrhea, strep throat, or
pneumonia existed. Patients with
infected wounds often had to
have a wounded limb removed, or
face death from infection. Now,
most of these infections can be
cured easily with a short course
of antimicrobials.
However, the future
effectiveness of antimicrobial
therapy is somewhat in doubt.
Microorganisms, especially
bacteria, are becoming resistant
to more and more antimicrobial
agents. Bacteria found in
hospitals appear to be
especially resilient, and are
causing increasing difficulty
for the sickest patients–those
in the hospital. Currently,
bacterial resistance is combated
by the discovery of new drugs.
However, microorganisms are
becoming resistant more quickly
than new drugs are being made
available; thus, future research
in antimicrobial therapy may
focus on finding how to overcome
resistance to antimicrobials, or
how to treat infections with
alternative means, such as
species-specific phages.