The concept of one microorganism killing another was introduced by Pasteur
who coined the term antibiosis in 1877, but it was much later that this concept
was realised in the form of an actual antibiotic. In 1929, the microbiologist
Alexander Fleming published his observation about the inhibition of the growth
of Staphylococcus aureus on an agar plate contaminated with Penicillium
notatum. Three years later, it was shown that the growth inhibition was due to
penicillin. The work was taken up further at Oxford University by pathologist
Howard Florey and biochemist Ernst Chain. The first clinical trials with penicillin
were undertaken in 1941. During the late 1940s the fungus Cephalosporium
acremonium (now renamed Acremonium chrysogenum) was isolated
from the sea at Cagliari (Italy) by Guiseppi Brotzu. This fungus was found to
produce a b-lactam compound designated cephalosporin. The discovery of
antibiotics for clinical use started with a b-lactam compound and is perhaps
the most important discovery in the history of therapeutic medicine. The
application of antibiotics to the therapy of infectious diseases may conceivably
have saved more lives than any other medical therapy. The success of b-lactams
in the treatment of infectious disease is due to their high specificity and
their low toxicity. Despite a growing number of antibiotics and the incidence
of penicillin-resistant isolates, b-lactams are still by far the most frequently
used antibiotic.