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Fighting Back
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ACTIVIT Y OVERVIEW
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SUMMARY
How was the first antibiotic discovered? What were the problems encountered in testing and producing this “miracle drug”? Students view historic footage and photographs that help bring alive the climate of the time and the personalities involved.
KEY CONCEPTS AND PROCESS SKILLS
1.
Tracing the history of science demonstrates how individuals contributed to the
development of modern scientific ideas, and reveals important interactions
between science and society.
2.
Scientific problem solving is a varied process that depends on the individual,
the scientific discipline, and the task.
3.
The traditional scientific method is generally defined as the following steps:
state the problem or question, propose an explanation (also known as a
hypothesis), collect evidence (frequently by conducting an experiment),
analyze data, and draw conclusions.
4.
Most infectious diseases are caused by microbes.
5.
The category of “microbes” includes microorganisms, such as bacteria and
protists, and also viruses, which are not considered to be alive.
6.
Antibiotics are effective against many bacterial infections, but not against viral
infections. The development of antibiotics has significantly improved the
chance that an individual will survive a bacterial or fungal infection.
KEY VOCABULARY
antibiotic
microbe
bacteria
scientific method
evidence
Teacher’s Guide
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Activity 50 • Fighting Back
MATERIALS AND ADVANCE PREPARATION
For the teacher
1
A Science Odyssey: “Matters of Life and Death” video
1
transparency of Student Sheet 50.1, “Notes on Penicillin” (optional)
*
1
videocassette recorder
*
1
television monitor
*
1
overhead projector
For each student
1
Student Sheet 50.1, “Notes on Penicillin” (optional)
*Not supplied in kit
n Teacher’s Note: Always preview the video segments from A Science Odyssey. The
video footage is not divided into sections; however, a clear beginning and end typically mark each segment. Cue to the segment on penicillin, which is approximately
16 minutes in length. The segment begins 43 minutes into the tape with the host
entering a house carrying a doctor’s bag. The first five minutes of the segment show
events leading up to the discovery of antibiotics. (Different segments of the video will
be viewed at different points of Science and Life Issues.)
A Science Odyssey: “Matters of Life and Death” Table of Contents
Hour 1
Hour 2
Prologue and Introduction
Introduction
Bubonic Plague
Heart Surgery
Pellagra
Organ Transplants
Diabetes
Cancer
Penicillin
Role of Modern Medicine
TEACHING SUMMARY
Getting Started
1.
Discuss possible reasons for improvements in public health and review the
elements of good experimental design.
Doing the Activity
2.
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Students watch a video segment on the discovery of penicillin.
Science and Life Issues
Fighting Back • Activity 50
Follow–Up
3.
Use the Analysis Questions to summarize ideas presented in the video.
INTEGRATIONS
History
Students can consider the effect that antibiotics had on the outcome of World War II.
The video mentions that more soldiers died from infection of their wounds than from
the initial trauma. Students could research the effects of infection and illness in general on the outcomes of other wars, such as the Civil War.
Language Arts
Many literature connections depict life before modern public health measures and
medical advances were available to prevent or treat many infectious diseases. The literature of Charles Dickens depicts the appalling social conditions in England in the
1800s, before advances in public health, nutrition, and medicine. His stories were read
by the wealthy and were influential in improving conditions of the working class.
Other literature links include Frank McCourt’s Angela’s Ashes and Laura Ingalls
Wilder’s Little House books. Such autobiographical novels communicate how important both public health measures and medical advances were to improving conditions
for the majority of people.
BACKGROUND INFORMATION
History of Penicillin
The germ theory of disease gave early 20th century scientists a goal: to find a chemical
that could kill bacteria but not the patient. World War I increased pressure to discover
something that could save the lives of wounded soldiers dying of post-injury infection.
Alexander Fleming, a British physician, treated soldiers in Northern Europe during
WWI. More soldiers were dying from infections than from war wounds. Fleming first
tried pouring antiseptic onto wounds in an effort to prevent infection, but it was not
very effective. After the war, he returned to England and, for ten years, did research,
looking for a substance that would kill bacteria. While he was on vacation in 1928, a
plate containing growth medium accidentally became contaminated with mold spores,
probably from another lab. Around this colony of Penicillium mold was a clear area
where bacterial colonies did not grow. Fleming mixed some of this mold with his own
blood and discovered it did not harm red blood cells. He suspected that this was the sub-
Teacher’s Guide
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Activity 50 • Fighting Back
stance that he had been looking for and called it penicillin, after the mold Penicillium. He applied penicillin topically to infections, but this was not successful.
The concentration required to be effective was extremely high and he could not
extract enough from the mold. Fleming published his findings in 1929, preserved
some of the Penicillium mold, and moved on to other areas of study.
Sulfa drugs became popular during World War II because sulfa could be poured
directly into the wound. This stopped the growth of bacteria, thus allowing the
body’s own defenses to fight the infection. However, sulfa drugs were not effective for severe infections and also had side effects.
In 1940, a team of Oxford University researchers (including Howard Florey and
Edward Chain) came across Fleming’s research and obtained a sample of Penicillium. Mice were injected with a fatal dose of Streptococcus bacteria; some of the
mice were then treated with penicillin. All of the mice injected with penicillin
survived, while those not treated with penicillin died. Although this method
used less penicillin per treatment than required topically, the problem of
extracting enough penicillin remained. The Oxford team turned to the U.S. government and U.S. drug companies to assist them with production. By 1944,
there was enough penicillin to treat all of the Allied soldiers in WWII. By the end
of the war, penicillin had saved thousands of lives. For this work, Fleming, Florey, and Chain shared the Nobel Prize for medicine in 1945.
Role of Serendipity
Fleming’s serendipity has parallels in other areas of science. Radioactivity was
discovered from the observation of a fogged photographic plate that had been
held down by a piece of uranium ore. Jenner observed that milkmaids seldom
caught smallpox, leading to his investigation and eventual development of the
cowpox vaccination for smallpox. Wegner noticed that Africa and South America “fit together,” forming the basis for his theory of continental drift. Although
many people observe interesting things, drawing connections and developing
explanations often requires curiosity, insight, imagination, and determination.
REFERENCES
Public Broadcasting Service (PBS). A Science Odyssey: “Matters of Life and
Death” (video). United States, 1998.
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Science and Life Issues
Fighting Back • Activity 50
TEACHING SUGGESTIONS
GETTING STARTED
1.
Review the concept of scientific methods with students. Ask, What makes a good scientific study?
Review the concepts of scientific design, variables,
controls, and good lab procedures. Inform them that
Discuss possible reasons for improvements
they will be looking for these things as they view a
in public health and review the elements
video about the discovery of penicillin.
of good experimental design.
n Teacher’s Note: Activities 50–52 work together to
develop key concepts. Note that Activity 50 provides an historical perspective on the discovery of
antibiotics, Activity 51, “The Full Course,” demonstrates the importance of taking antibiotics correctly, and Activity 52, “Miracle Drugs—Or Not?” presents a current issue regarding the proper use of
antibiotics.
DOING THE ACTIVIT Y
2.
Students watch a video segment on the
discovery of penicillin.
n Teacher’s Note: This video contains too much
information to absorb in one showing. As many
middle school students have trouble paying attention to a video and writing at the same time, consider showing the video, discussing it, outlining
Have students brainstorm responses to the question:
note-taking strategies, and then showing it again for
Why has life expectancy in the U.S. increased by
students to take notes. Be sure to inform students
more than 30 years in the last century? Ideas may
ahead of time if they do not have to take notes the
include the increased use of vaccines, other medical
first time through.
advances, better sanitation, and better (and more)
food.
After the first showing, ask students to discuss in
their groups: What surprised you about how peni-
Tell students that one factor has been improve-
cillin was discovered and brought to mass produc-
ments in the treatment options for infectious dis-
tion? Their ideas may include the role of serendipi-
eases. Students studied antimicrobial solutions in
ty in how penicillin was discovered, the fact that
Activity 47, “Reducing Risk.” Review which antimi-
Fleming was unable to successfully develop wide-
crobials worked. Then ask, Could this antimicro-
spread treatments from his discovery, and the
bial be injected into people to help them fight infec-
absence of safety checks in the clinical trial process.
tion? The idea of injecting bleach solution, etc.
To reinforce the idea of scientific methodology,
should seem dangerous—it would also kill human
briefly discuss how the discovery and use of peni-
cells and could kill the patient. Point out that this
cillin did or did not model good scientific methods.
was the dilemma faced by scientists working to dis-
Students may also be surprised that a mold is the
cover an antimicrobial medicine that could fight
source of penicillin.
infections inside the body.
Teacher’s Guide
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Activity 50 • Fighting Back
If appropriate, prepare students to take notes dur-
researchers at Oxford University who revived Flem-
ing the video by modeling the use of Student Sheet
ing’s discovery ten years later and conducted ani-
50.1, “Notes on Penicillin,” and filling in a few
mal and clinical trials. This part may be a little more
points. A completed Student Sheet is shown below.
difficult for students to take notes on, as the “dis-
Show the video again. You may wish to stop the
video where Fleming shows his famous plate. Ask
students, How does this plate compare to your
results with antimicrobial solutions on bacteria
colonies in Activity 47, “Reducing Risk”? The clear-
covery” is less obvious. Chain and Florey found a
way to make more penicillin and conducted trials to
test its effectiveness and safety. Allow students time
to finish their notes before discussing the Analysis
Questions.
ing around the fungal colony is analogous to that
FOLLOW–UP
around the antimicrobial disks in Activity 47.
It may help students if you stop the video at the
3.
Use the Analysis Questions to summarize
ideas presented in the video.
point where the narrator comments that Fleming
lost interest in his discovery (about 8 minutes into
Begin by reviewing the notes taken during the
the segment) and allow students to catch up on
video. You may want to emphasize the timeline of
their notes. After this point, the focus is on the
events as presented in the video. These events can
Student Sheet 50.1: Notes on Penicillin
Alexander Fleming
What scientific
discovery was
made?
Penicillin destroys the cell wall of
bacteria, but does not affect human
blood cells in test tubes.
Oxford University team
Penicillin can be injected into living
organisms to fight bacterial infections.
How was this
discovery made?
Penicillium fungi spores float in from
another lab and begin to grow on
discarded bacterial cultures. Fleming
observes that this mold appears to
prevent the growth of bacteria.
He begins to experiment with this
mold, and finds that (in the lab) it
works against many different
disease-causing bacteria.
Ernst Chain and Howard Florey design an
experiment in which mice are injected with
the fatal Streptococcus bacteria. Half of the
mice are then given injections of penicillin.
Within 16 1⁄2 hours, all of the control mice
are dead while the mice given penicillin
appear normal. Later, they begin to treat
human patients, demonstrating success at
using penicillin against human bacterial
infections.
What was done as
a result of this
discovery?
Fleming’s experiments focus on using
penicillin topically. He cannot make
enough for it to be effective and gives
up trying to use it to treat infections
in humans. However, he writes an
article on the antibacterial properties
of penicillin that is published on May
10, 1929. In addition, he preserves a
small amount of the Penicillium mold.
The team obtains help from U.S. drug
companies to increase production of
penicillin and effectively treat people.
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Science and Life Issues
Fighting Back • Activity 50
be placed in the context of the timeline created in
has been an essential factor in the survival of
Activity 37, “The History of the Germ Theory of Dis-
many individuals during the last 60 years.
ease.” The outbreak of World War I causes scientists
The doctor at the end of the video segment
to focus on compounds that can kill bacteria. In the
stressed the importance of antibiotics by ask-
late 1920s, Fleming’s work focuses on this area, and
ing his students how many may owe their own
his paper is published in 1929. In 1933, a German
lives to antibiotics. Ask students in your class-
chemist utilizes the antibacterial properties of sulfa
room how many of them have taken antibi-
drugs to create a powder that could be sprinkled
otics. Let a few students share their stories. This
directly onto wounds (although this treatment is
is also a good time to have students share sto-
used in World War II, it is not always successful).
ries about how the lives of their parents or
The Oxford team begins their work in 1938; during
grandparents may have been affected or saved
World War II, they continue to increase production
by the use of antibiotics against potentially life-
of penicillin. By the time the war ends, U.S. drug
threatening infections.
companies are making 650 billion units of peniTo help make the importance of antibiotics more
cillin a month.
relevant and personal, ask students whose lives
Analysis Questions 2 and 3 can be completed as
have been saved by antibiotics to stand up. Have
homework if most of the key points about the sci-
students whose parents’ or grandparents’ lives
entific methodology and the importance of antibi-
were saved by antibiotics stand up too; these stu-
otics have been addressed in class.
dents may not have been born if their parents or
grandparents had not survived the infection.
SUGGESTED ANSWERS
TO ANALYSIS QUESTIONS
2.
Think back to the traditional scientific method, first
discussed in Activity 1, “Solving Problems: Save
1.
Describe the impact of penicillin on society.
Fred!” in Unit A, “Studying People Scientifically,”
Penicillin changed the way that people
of Science and Life Issues. Explain how the work of
who had bacterial diseases were treated.
each of the following scientists did or did not resem-
Instead of waiting to see if an individual would
ble the traditional scientific method.
fight off a disease and survive, antibiotics were
used to attack the infection and increase the
survival rate.
n Teacher’s Note: Emphasize to the class that
the use of antibiotics is fairly recent; Florey and
a. Alexander Fleming
b. Oxford University team (made up of 19
researchers, including Howard Florey and Ernst
Chain)
Chain did their work in the 1940s. As this may
Fleming’s discoveries demonstrate both the sci-
appear a long time ago to students, have them
entific method and the role of serendipity and
evaluate this information in the context of their
vision in science. Initially, Fleming was research-
own relatives (see paragraphs below). As men-
ing bacteria. The video does not provide any
tioned in the video, the discovery of antibiotics
Teacher’s Guide
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Activity 50 • Fighting Back
information on exactly how he addressed his
use of Penicillium as an antibacterial agent.
questions, except that he systematically worked
Based on Fleming’s work, they hypothesized
with different bacteria and anti-bacterial agents.
that this mold could be injected as a form of
During this time, he was conducting experi-
treatment. They collected evidence of this by
ments (collecting evidence); in fact, his work
conducting experiments, first on mice and then
provided the basis for his own as well as future
on humans. The data supported their hypothe-
scientists’
also
sis and they were able to conclude that peni-
observed and analyzed data that he collected
cillin could be used safely and effectively to
accidentally. Many people would have discard-
treat bacterial infections in humans.
hypotheses.
However,
he
ed the cultures and not noticed the potential
importance of the Penicillium mold. Based on his
hypothesis that the mold was affecting the
growth of bacteria, he designed and conducted
3.
What types of infectious diseases do antibiotics
work against? Are there any types of infectious diseases that antibiotics do not work against? Explain.
experiments that confirmed the antibacterial
Antibiotics work against bacterial diseases. Stu-
properties of penicillin. In addition, Fleming
dents have studied two bacterial diseases over
published his results and preserved specimens
the course of the unit: Hansen’s Disease and the
of the mold for future experimentation; this was
bubonic plague. These diseases often respond to
essential to the work of Florey and Chain, who
antibiotics if they are given in time. Bacterial
used this preserved specimen.
diseases for which students may have received
The work done by the Oxford University team
also illustrates elements of the traditional scientific method, and demonstrates how scientists build on one another’s work. First, the
team had a defined problem to investigate: the
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Science and Life Issues
antibiotics include streptococcal infections of
the throat and ear, cuts, some sinus infections,
and bacterial pneumonia. Antibiotics do not
work against viral diseases like the flu, colds,
chickenpox, measles, polio, and HIV.
Name
Date
Notes on Penicillin
Alexander Fleming
Oxford University team
What scientific
discovery was made?
How was this
discovery made?
©2006 The Regents of the University of California
What was done as a
result of this discovery?
Science and Life Issues Student Sheet 50.1
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