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50 40 o5 1 0 -m i n u t e s es si LE CT -t on Fighting Back VI ACTIVIT Y OVERVIEW EW AND RE F 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 C-251 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. C-252 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 C-253 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. C-254 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 C-255 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. C-256 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 C-257 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 C-258 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 C-259