Set up lab students for real-world success with field work that addresses a real-world question: How do bacteria fight antibiotics?
Assistant Professor of Biology, Birmingham-Southern College
PhD in Microbiology, BS in Biology
Biologist Kevin Drace, PhD, of Birmingham-Southern College in Alabama, has more than a passing interest in heavy metal. No, not the music: the elements on the periodic table—such as lead, mercury, silver, and copper—that are toxic to both microbial and human cells. In particular, he is fascinated by the fact that certain strains of bacteria seem innately immune to these metals’ deleterious effects.
“Resistant bacteria have some mechanism that allows them to persist and grow in environments that have higher-than-normal levels of heavy metals,” Drace explains. “I am most interested in bacteria that use what are called efflux pumps: structures that kick in when the cell is penetrated by heavy metals. Each pump essentially pushes the metal back out of the cell before it can affect the cell’s interior components.”
Interestingly, the evolution of efflux pumps may help explain why some bacteria do not respond to courses of antibiotics, he notes. “A lot of multidrug-resistant bacteria have that resistance because they have these efflux pumps,” he says.
Drace shares his passion for the topic with the first-year students who take his Cell and Molecular Biology course, to whom he poses a research question that hits very close to home:
When environmental pollution selects for microorganisms that use efflux pumps for heavy metal resistance, does this defense mechanism also lead to antibiotic resistance?
Drace’s students are uniquely positioned to seek out the answer, as Birmingham, Alabama, historically has had a problem with environmental pollution. While far from ideal for the residents, it does provide meaningful opportunities for these budding biologists.
Challenge: Unrealistic labs, lack of crucial skills
Traditionally, says Drace, Cell and Molecular Biology has been a fact-based course where students learn textbook concepts, reinforced by hands-on labs that take place in on-campus laboratories. “Lab has often been a place to extend your understanding of the concepts discussed in the abstract during lectures,” he says. However, that approach had its limits. The labs were set up to generate identical results every time, which is unrealistic in science. Further, because the lab materials are preselected and provided (not gathered), students would only learn data analysis. To be successful in the field, though, Drace says a biologist must be equally competent in the design phase and raw collection of data.
So Drace decided to evolve that paradigm. Instead of merely reinforcing concepts, lab work should help students “see what a biologist does and how a biologist uses the concepts and theories we learn about in lecture in a practical way,” he explains.
Lastly, he wanted to try an approach that would help students expand their horizons to include life beyond campus. “The college has a goal of connecting students—especially first-semester freshmen—to their community,” he says. “It’s an important way that we leverage our role as an urban liberal arts college. We want our students to develop that sense of ownership in the neighborhood.” That would be understandably difficult to achieve without leaving the confines of a campus lab.
Innovation: Collecting local samples, addressing global issues
Drace says he has tried to create an experience in his Cell and Molecular Biology lab for new freshmen that is as close as possible to the real-life experience of a working scientist: As a result, he has created a lab that enables students to become involved in the community, while addressing a scientific concern that could have implications for medicine worldwide.
For several years, Drace has been reinforcing his students’ understanding not just of the lab-bench exercise of biology but of its practical application. “We have moved from the cookbook, planned-experiment approach used in traditional lab courses,” he says. “Today, the lab is more a place where students can practice the art of being a scientist.”
“We have moved from the cookbook, planned-experiment approach used in traditional lab courses. Today, the lab is more a place where students can practice the art of being a scientist.”— Kevin Drace, PhD
An important example is in the collection of samples for laboratory testing. Drace does not simply pass out samples in jars; he sends students out into the field to collect test samples in the wild. In previous years, he took students as far afield as Mozambique and Ecuador; however, that was very limiting, as only a handful of students could be accommodated at once. So Drace began to look for opportunities in his own “backyard.”
After doing some research and outreach, the professor came to an agreement with the administrators of a local decommissioned coke plant called Sloss Furnaces—a coal-processing site that now serves as an education center and is listed on the National Historic Registry.
“We take our students to this site, and they collect samples of soil that we know is contaminated with heavy metals and organic pollutants,” Drace explains. “They use those samples in lab experiments to determine how those pollutants affect bacteria in the soil.”
“We’ve built in the opportunity for reiteration. There is time for students to do an experiment and fail; they can still collect data and come up with ideas to revise their technique. They can always learn something new through the experiment because it failed. That’s a lot of what a scientist does in the real world.”— Kevin Drace, PhD
Frequency: Three 60-minute lectures and one 3-hour lab per week for 15 weeks
Class size: 108 (18 per laboratory section)
Course description: An investigation of the fundamental properties of cells. Topics include cell structure and function, energetics and metabolism, gene structure and expression, and the techniques used to study these phenomena. Designed for students who plan to major in biology or one of the natural sciences and/or who are pre-health.
See resources by Kevin Drace, PhDSee materials
Lesson: Treating students as scientists
For the course’s first lab, Drace and his colleagues charter buses for the class’s six sections of students to take them to Sloss Furnaces. The students tour the site and talk to a historian who provides the background on the former operation and its role in the iron and steel industry. Then students collect soil samples for use in upcoming lab work. The field trip takes 2–3 hours.
The approach may sound simple, but it is the beginning of Drace’s much broader plan: to turn students into scientists who have real-world experience doing lab work of vital importance.
Here are some strategies Drace employs to encourage as much practical application of science as possible:
Encourage decision-making during sample collection
Drace says a drawback of traditional labs is that they are very scripted; students are told exactly what to do when, which may not be the case if they do research in their future career. So Drace allows students to take the helm when possible and practical.
For example, during the plant tour, the guide will point out some of the likelier places to look for contaminated soil: where the coke ovens were, where various processes took place, and where waste was stored. But ultimately, the students decide for themselves where to collect their samples. “We’re not too concerned about where they collect their samples, as long as they take ownership of the process,” Drace says. “Part of what we’re trying to do is give them the opportunity to make their own choices.”
Give students ownership of the experiment
After sample collection, students work in the lab to isolate lead-resistant bacteria, characterize them, and quantify their levels of resistance. Then they test these bacteria for antibiotic resistance, which overlaps substantially with heavy metal resistance. Finally, students must come up with their own hypothesis about the data they are seeing.
“These are their own isolates—up to three per student,” Drace asserts. “So they have individual ownership of the experiment.” That the samples are from local soil also furthers the college’s goal of encouraging students to feel ownership of and responsibility to their wider off-campus community.
Engage them in scientific reading and writing
Professional scientists must be able to clearly communicate their findings—and understand the findings of others. So, over the course of the semester, students read research papers explaining concepts such as heavy metal resistance, efflux pumps, and antibiotic resistance—both to deepen their understanding of these ideas and to help them understand how scientists communicate. Worksheets demonstrating their understanding of the literature are among the assignments that are graded.
“Throughout the course, we are building toward development of an overall laboratory report, modeled on a scientific paper,” Drace says. “I have them turn in successive drafts, including the graphs and figures they make using the data they collect. The report they turn in at the end of the semester also is assessed.”
Allow for both failure and success
One thing that lends authenticity to students’ experience is the realization that failure and repetition are important parts of the laboratory process. It may go without saying, but labs in the real world do not always go as planned.
“We’ve built in the opportunity for reiteration,” says Drace. “There is time for students to do an experiment and fail; they can still collect data and come up with ideas to revise their technique. They can always learn something new through the experiment because it failed. That’s a lot of what a scientist does in the real world.”
He adds that students’ grades are not dependent upon whether or not the lab results were “correct” but on the quality of their lab notebook, class participation, and laboratory report. Drace has found that this approach to laboratory teaching has created a new kind of incentive to succeed—not grade-driven but characterized by an intrinsic desire to conquer the problem for its own sake.
“We look at the community more from an environmental justice perspective. With our skills as biologists, we can contribute to making the city a better place.”— Kevin Drace, PhD
Discuss the potential implications
Ultimately, the work that scientists do can impact government policy, business and industry, the medical field, and more. In Drace’s course, students are studying an interesting microbiological mechanism, as they might in a traditional lab. The difference is that, concurrently, they are examining questions that may have really important practical implications. As mentioned, the experiment enables students to explore the question of whether heavy metal emission ultimately promotes drug-resistant bacteria, which might lead to other life-saving research on antibiotics. He also asks them to consider whether a community’s policy makers should account for this risk in land use or environmental decisions.
Drace notes that his overall approach can be adapted to suit a variety of majors, raising student’s consciousness of community, policy, and more. “Birmingham has a long list of historical issues, so another department might come at it from a civil rights perspective,” he offers by way of example. “We look at the community more from an environmental justice perspective. With our skills as biologists, we can contribute to making the city a better place.”
Cost could be an issue for some academics who are attracted to Drace’s methodology. “It costs us $1,500 to charter the buses,” he says. “That can be an obstacle for some institutions. For us it was a useful investment because we didn’t feel comfortable asking first-semester freshmen to drive to the location themselves the first week they arrive on campus.”
He adds that it may not be necessary to travel very far to find what is needed to replicate the experiment. “Truthfully, in most urban environments, the soil is going to show a certain amount of lead contamination, mostly from historical use of leaded gasoline or lead-based paints in older homes,” he says. “There will always be some heavy metal resistance among the bacteria, so the specific location is not as important.”
How to Apply This Lesson to Non-Sciences
Drace suggests one of the more important outcomes he has seen is the connection that students develop with their community because of the field data-collection exercise.
“I could see not only academics in biology or the physical sciences benefiting from this but also historians,” he says. “The history student would acquire the skills and tool sets of a historian but also would gain a lot from seeing how scientific techniques are best applied in this particular community with these particular problems. The field trip would allow the student to go beyond learning about these historical events and actually investigate how history affected the local community in a real way.”
Thanks to this lab work, students report that they have a more confident feel for what it is like to do science. Sometimes, this affirms their interest in a career as a biologist, Drace says. Sometimes it has the opposite effect. “I have had some students come away from the experience convinced that science isn’t for them,” he allows. “They may say, ‘I never realized failure was such a big part of science.’ They may not be prepared for how long an experiment can take. They may be starting with a naïve perspective, and if they do not appreciate a scientist’s life, disillusionment may have a benefit by helping the student understand their values and interests more quickly.”
For other students, the approach is highly motivating: One of Drace’s recent students repeated her investigation of heavy metal resistance in bacteria twice—both iterations ending in failure to obtain usable data. “She was frustrated by that,” Drace recalls. “She did what she was supposed to do, but the experiment just didn’t work.”
Unlike most students, however, after the entire laboratory experience was completed, she chose to come back and try again. “After that week of labs was finished, she reached out to me and said, ‘Hey, I know everything is already turned in and this won’t affect my grade, but it bothers me that I didn’t get results,’” Drace relates. “‘Is it OK if I come in after hours and continue to work on this problem?’ I reminded her that none of this really affected her grade—either the initial failure to get results, or whether she got it to work on the third try. But she insisted; she wanted to get results on her own initiative.”
Drace has seen similar drive with other freshmen, one he has never seen in students in the usual “cookbook” labs where the experiment is contrived to succeed.
Two other students had this to say about the approach:
“I love that the lab component incorporated researching soil samples and bacteria. It made me feel productive and made the research feel relevant. I loved the experience and all the new techniques we learned this semester.”
“[The labs] were very informative not only pertaining to Biology, but other related studies. While reading journal articles for other classes, [the] materials and processes discussed and executed in this class gave me a better understanding of the article itself.”