As disease-causing bacteria becomes increasingly resistant to antibiotics, scientists like Erin Carlson from Indiana University are turning to natural sources to find new medicines. "Science Behind the News” is produced in partnership with the National Science Foundation.
Science Behind the News- Drug-Resistant Bacteria
TOM COSTELLO, reporting:
From MRSA to deadly strains of E. coli and pneumonia, superbugs are a major public health concern.
BRIAN WILLIAMS (file): Another of these so-called super bug infections, this one going after children, and it’s resistant to drugs.
COSTELLO: Superbugs are bacteria that have become resistant to antibiotics, usually due to the overuse or misuse of these important medicines.
ROBERT BAZELL (file): Bacteria have a long history of mutating to overcome every antibiotic that medicine has thrown at them.
COSTELLO: In order to develop newer, stronger types of antibiotics, scientists are looking outside the lab for potential solutions.
Professor ERIN CARLSON (Indiana University): I’ve always been really concerned about infections and how we can treat them and historically the best way to do that is by natural products.
COSTELLO: Erin Carlson is a chemistry professor at Indiana University, and has been funded by the National Science Foundation. She and her team are looking for new sources of medicine from living organisms such as trees, plants, and microbes - microscopic organisms found in soil.
CARLSON: So, often people will look for molecules that have a particular bioactivity. They will take an extract and they’ll treat a certain cell with it to see if it kills the cell or if it causes the cell to behave in a certain way. Once they see that extract material has the ability to kill the cells, then the challenge is to try and figure out the exact molecule in the extract that’s doing that activity.
COSTELLO: A key part of Carlson's research involves finding ways to extract potential bacteria-fighting molecules from their natural sources. To do this, Carlson's team uses a method called conjugation which involves using chemistry to "tag" and then separate out the molecules.
CARLSON: We actually take the natural product extracts and conjugate them to a large piece of material that helps us pull them out of the extract source.
COSTELLO: Finding medicinal solutions in nature is not a new idea. About 70% of treatments for infectious diseases have come from natural sources, such as penicillin. And for thousands of years, native cultures from around the world, from Africa to the Far East, have been using extracts from plants and insects to treat ailments.
CARLSON: Things like eating tree bark for relief of pain, and it turns out that, for example, tree bark from some trees contains a molecule that has now been developed into aspirin.
COSTELLO: Carlson's research focuses on Streptomyces, a strain of bacteria found in soil and water that is in two-thirds of antibacterial agents produced in nature. Streptomyces plays a part in the decomposition of organic matter in the soil because it contains chemicals that kill or inhibit the growth of microorganisms.
CARLSON: We did a collection trip this summer, and we went to northern Wisconsin and Minnesota, and Streptomyces is found in soil, and so we were collecting soil samples from a lot of different, diverse areas like ponds and areas near garbage and areas near gardens that have been heavily fertilized.
COSTELLO: Carlson's research involves a branch of chemistry known as sustainable or green chemistry. It encourages the design of products that are less hazardous to human health and the environment, including reducing waste, using nontoxic components, and designing chemical products from renewable resources.
CARLSON: We all know that it’s important to sustain resources for fuel to power our cars. It’s important to sustain resources for food that we eat. In my lab, we do have concern about keeping the global diversity of organisms alive so we can search for natural compounds that could be potential drugs.
COSTELLO: And among the most coveted of these potential drugs would be one that fights drug-resistant bacteria.
CARLSON: It will be really amazing for us if we can contribute molecules and strategies to help us treat patients that currently have almost no options for curative therapies.
COSTELLO: As Carlson continues to locate and test new organisms found in nature, she may be leading the way to finding new antibiotics to combat even the most powerful of superbugs.
If the phrase “too much of a good thing” applies to anything, it surely applies to antibiotics. Their discovery was one of the most important medical advances of the last century, but overuse has eroded their effectiveness.
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