Part V. Solutions to the Antibiotic Problem

Activity E) What is the Future of Antibiotics?—Teacher’s Guide

Overview: Students will apply their new knowledge of evolutionary concepts, as well as their knowledge of the antibiotics problem and its causes to discuss possible solutions.

Learning Objectives: Students will understand that understanding evolution and evolutionary concepts is critical to identifying possible solutions to this growing health problem.

Class Time: 1 day

In this exercise, students will discuss potential solutions to the antibiotic problem. They will begin by reading an article (as a homework assignment), and come to class prepared to discuss the article (have the students fill out the worksheet as they are reading the assigned article). The overall learning objective is for students to understand that understanding evolution and evolutionary concepts is critical to identifying possible solutions to this growing health problem. The article is used as a jumping-off point for discussion. The discussion should be student-oriented, with the teacher guiding the discussion towards higher thinking objectives (analysis and synthesis).

There are several ways to approach this. You could have each student read the same article, or you could assign several articles, one to each student, in a jigsaw-type exercise. In this case, within each small group of 3-4 students, each student would be the “expert” on their article, summarizing the article for the other students. This method may be preferable, since no one article lists all possible solutions.

As a spin-off, you might ask students to think about how the recent anthrax scare, and consequent stockpiling of cipro by individuals may affect our ability to respond in the case of an actual bioterrorism event. See the web site of the Alliance for the Prudent Use of Antibiotics for a discussion of this problem and related links.

Suggestions for Articles:

Braffman-Miller, J. Beware the rise of antibiotic-resistant microbes. USA Today Magazine. March 1997.
[This article is a bit long, but has a good overview of the history of antibiotics, the problem of antibiotic resistance (including a “close to home” discussion of a TB outbreak in a California high school), the reasons for the problem (including an explicit discussion of evolution), and potential solutions (vaccines, limiting use in humans, new antibiotics.) This would be a good article if you feel your students need the overview]

Christensen, D. Keeping bugs from pumping drugs. Science News. Feb. 12, 2000.
[This article details efflux pump inhibitors, which inhibit bacteria from pumping antibiotics out of their cells—one type of resistant mechanism. This drug may give new life to antibiotics that are now useless because of resistant bacteria. These drugs are also mentioned in Travis’ article.]

Levy, S.B. The challenge of antibiotic resistance. Scientific American, March 1998.
[This article is long, but written by a leading researcher in the field of the evolution of antibiotic resistance (one of the researchers interviewed in Radetsky’s article). It discusses the problem of resistance, as well as a problem that is often overlooked: the affect of antibiotics on the benign bacteria that normally help keep pathogenic bacteria in check. It discusses ways to reverse resistance (i.e. solutions to the problem), and also includes a box on the potential effects of antibacterials in household products.]

Nemecek, S. Beating bacteria: new ways to fend off antibiotic-resistant pathogens. Scientific American. Feb.,1997.
[This is a very short article that basically lists several novel methods researchers are using to combat resistant bacteria, including genomics, new natural resources, synthetic chemicals, and bispecific antibodies.]

Radetsky, P. Last days of the wonder drugs. Discover. Nov. 1998.
[This is a bit long, but a very good article. It explicitly deals with the problem of antibiotic resistance, and a potential solution based on evolutionary biology (including interviews with two evolutionary biologists working on this problem). The solution discussed is prudent use, with the hope of reverting bacterial populations to susceptibility.]

Travis, J. 1994. Reviving the antibiotic miracle? Science 264 (5157): 360.
[Despite being in Science, this is actually a review article that discusses new research into fighting bacteria. It describes several novel approaches, including “disarming” bacteria, rather than killing them, and new drugs, such as chemicals that block the pumps that resistant bacteria use to remove antibiotics from cells.]

Points of Discussion/Questions to Guide Discussion:
• As long as we use antibiotics against bacteria, they will evolve resistance. The question is, how can we manage/slow down this process? Since human behavior (overuse and misuse of antibiotics by industry, doctors, patients) is speeding up the evolution of resistance, how can we try to change human behavior to slow this evolutionary process down?

• Be explicit about how understanding evolution is critical in identifying solutions (although implementing these solutions is a different question—see next point).

• In addition to the medical/scientific aspects of this problem, you may also want to discuss political and economic aspects as well (e.g. what will decreasing the use of antibiotics in agriculture do to productivity? how do we implement programs to effect change in our country, as well as encourage it in other countries?)

• Be sure to cover the following points:

Read your assigned article for homework. During the next class, we will be discussing potential solutions to the problem of antibiotic resistance. As you read your article, answer the following questions:

1) While reading the article, identify and define any words that were unfamiliar to you.

2) Summarize the three or four main points the author tries to make in the article.

3) What does the author view as the problem(s) with antibiotics?

4) What does the author suggest as solutions to these problems?

5) Can you think of any other solutions?