Flu: The great flu epidemic of 1918 WORLD OF MICROBIOLOGY AND IMMUNOLOGY220•
even as he expanded his research projects into new areas, such
as cancer studies. During the mid 1930s, sulfonamides, or
sulfa drugs, had been introduced as clinically effective against
streptococcal infections, an announcement which boosted
Florey’s interest in the field. At Florey’s suggestion, Chain
undertook biochemical studies of lysozyme. He read much of
the scientific literature on antibacterial substances, including
Fleming’s 1929 report on the antibacterial properties of a sub-
stance extracted from a Penicillium mold, which he called
penicillin. Chain discovered that lysozyme acted against cer-
tain bacteria by catalyzing the breakdown of polysaccharides
in them, and thought that penicillin might also be an enzyme
with the ability to disrupt some bacterial component. Chain
and Florey began to study this hypothesis, with Chain concen-
trating on isolating and characterizing the enzyme, and Florey
studying its biological properties.
To his surprise, Chain discovered that penicillin was not
a protein, therefore it could not be an enzyme. His challenge
now was to determine the chemical nature of penicillin, made
all the more difficult because it was so unstable in the labora-
tory. It was, in part, for this very reason that Fleming eventu-
ally abandoned a focused pursuit of the active ingredient in
Penicillium mold. Eventually, work by Chain and others led to
a protocol for keeping penicillin stable in solution. By the end
of 1938, Florey began to seek funds to support more vigorous
research into penicillin. He was becoming convinced that this
antibacterial substance could have great practical clinical
value. Florey was successful in obtaining two major grants,
one from the Medical Research Council in England, the other
from the Rockefeller Foundation in the United States.
By March of 1940, Chain had finally isolated about one
hundred milligrams of penicillin from broth cultures.
Employing a freeze-drying technique, he extracted the yel-
lowish-brown powder in a form that was yet only ten percent
pure. It was non-toxic when injected into mice and retained
antibacterial properties against many different pathogens. In
May of 1940, Florey conducted an important experiment to
test this promising new drug. He infected eight mice with
lethal doses of streptococcibacteria, then treated four of them
with penicillin. The following day, the four untreated mice
were dead, while three of the four mice treated with penicillin
had survived. Though one of the mice that had been given a
smaller dose died two days later, Florey showed that penicillin
had excellent prospects, and began additional tests. In 1941,
enough penicillin had been produced to run the first clinical
trial on humans. Patients suffering from severe staphylococcal
and streptococcal infections recovered at a remarkable rate,
bearing out the earlier success of the drugs in animals. At the
outset of World War II, however, the facilities needed to pro-
duce large quantities of penicillin were not available. Florey
went to the United States where, with the help of his former
colleague, Alfred Richards, he was able to arrange for a U.S.
government lab to begin large-scale penicillin production. By
1943, penicillin was being used to treat infections suffered by
wounded soldiers on the battlefront.
Recognition for Florey’s work came quickly. In 1942,
he was elected a fellow in the prestigious British scientific
organization, the Royal Society, even before the importance ofpenicillin was fully realized. Two years later, Florey was
knighted. In 1945, Florey, Chain and Fleming shared the
Nobel Prize in medicine or physiology for the discovery of
penicillin.
Penicillin prevents bacteria from synthesizing intact cell
walls. Without the rigid, protective cell wall, a bacterium usu-
ally bursts and dies. Penicillin does not kill resting bacteria,
only prevents their proliferation. Penicillin is active against
many of the gram positive and a few gram negative bacteria.
(The gram negative/positive designation refers to a staining
technique used in identification of microbes.) Penicillin has
been used in the treatment of pneumonia, meningitis, many
throat and ear infections, Scarlet Fever, endocarditis (heart
infection), gonorrhea, and syphilis.
Following his work with penicillin, Florey retained an
interest in antibacterial substances, including the
cephalosporins, a group of drugs that produced effects similar
to penicillin. He also returned to his study of capillaries, which
he had begun under Sherrington, but would now be aided by
the recently developed electron microscope. Florey remained
interested in Australia, as well. In 1944, the prime minister of
Australia asked Florey to conduct a review of the country’s
medical research. During his trip, Florey found laboratories
and research facilities to be far below the quality he expected.
The trip inspired efforts to establish graduate-level research
programs at the Australian National University. For a while, it
looked as if Florey might even return to Australia to head a
new medical institute at the University. That never occurred,
although Florey did do much to help plan the institute and
recruit scientists to it. During the late 1940s and 1950s, Florey
made trips almost every year to Australia to provide consulta-
tion to the new Australian National University, to which he
was appointed Chancellor in 1965.
Florey’s stature as a scientist earned him many honors
in addition to the Nobel Prize. In 1960, he became president of
the Royal Society, a position he held until 1965. Tapping his
experience as an administrator, Florey invigorated this presti-
gious scientific organization by boosting its membership and
increasing its role in society. In 1962, he was elected Provost
of Queen’s College, Oxford University, the first scientist to
hold that position. He accepted the presidency of the British
Family Planning Association in 1965, and used the post to pro-
mote more research on contraception and the legalization of
abortion. That same year, he was granted a peerage, becoming
Baron Florey of Adelaide and Marston.See alsoBacteria and bacterial infection; History of the devel-
opment of antibiotics; Infection and resistanceFLU: THE GREAT FLU EPIDEMIC OF
(^1918) Flu: The great flu epidemic of 1918
From 1918 to 1919, an outbreak of influenzaravaged Europe
and North America. The outbreak was a pandemic; that is,
individuals in a vast geographic area were affected. In the case
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