Profile: A Pioneer Who’s Investigating How Bacteria Communicate

Joe Tyrrell | September 28, 2016 | Profiles
In an era of increasing antibiotic resistance, Dr. Bonnie Bassler’s research could revolutionize medicine by encouraging helpful bacteria and inhibiting the spread of pathogens

Dr. Bonnie Bassler
Who she is: Dr. Bonnie Bassler runs a research laboratory at Princeton University, where she chairs the department of molecular biology. She is also a Howard Hughes Medical Institute investigator.

Home: Born in Chicago, Bassler, 54, grew up in Danville, CA. She has lived for 22 years in Princeton, where she got a job, joined a swing dance class, and then married the instructor, Todd Reichart, a web and media specialist in the university’s chemistry department.

Her work: Dr. Bassler has pioneered research into “quorum sensing,” the way bacteria use chemical emissions to talk to each other. This brand-new field of scientific inquiry carries the potential to revolutionize medicine by providing new ways to prevent the spread of pathogens and encourage helpful bacteria.

Awards along the way: Bassler has won a MacArthur Foundation “genius” grant, been jointly honored by the National Academy of Sciences and the French Academy of Sciences, won a Shaw Foundation Prize in Hong Kong — “the Nobel of the East,” Laureate for North America in the L’Oreal-UNESCO Women in Science awards… We could go on, but we would run out of space.

Latest award: She is the second recipient of the Alice H. Parker Women Leaders in Innovation Award from the New Jersey Chamber of Commerce, an honor that left the normally loquacious professor choked up.

“This is a very personal, very local and very meaningful prize,” Bassler said. “Princeton is a very beautiful town to live and work in,” and the university “took a chance” by giving her a job, prolonged time for research and enthusiastic assistants, many of whom turned out to see her receive the award at the National Conference Center in East Windsor.

“I’m accepting this award on behalf of the people who made the discoveries for which I am being honored,” Bassler said.

Beyond the fringe: It’s a big change from 22 years ago, when she sent out 20 applications for a research position and got just two responses, with only Princeton inviting her to interview for a tenure-track position.

“What I was doing was very much fringe science, and not at all accepted by the science establishment,” Bassler said. “There was an almost snooty attitude” toward bacteria, “‘Oh, these tiny, ancient creatures aren’t very interesting, they never do anything fancy.'”

Changing minds (1): At the time, “very few women were being offered positions on scientific faculties,” Bassler said. And although progress has been made in some areas, she believes gender bias is still prevalent. “Women are woefully undervalued for their contributions in science,” she said.

Women in NJ science: The realization that so many New Jersey women have made major scientific and social contributions, without much publicity, is what spurred the chamber to establish the award last year, said its president, Tom Bracken.

Alice Parker, for whom the award is named, lived in Morristown. She patented a gas-fired furnace in 1919, the first major step toward the type of central heating commonplace today. But little is known of her life, beyond the fact that she attended Howard University. The chamber wants to prevent such oversights in the future.

“It’s an innovation state, and we want to celebrate these women innovators,” Bracken said. Not only are businesses increasingly recognizing that diversity is good for their bottom lines, but also it helps maintain the image of the state as an attractive place in which to live and work, he said.

In a period when the state is working to get out of its economic doldrums, “science and business and technology, it all gets intertwined,” Bracken said.

How she got there: After Bassler entered the University of California-Davis with a vague intention to become a veterinarian, dissections made her realize that “what I like is live animals.” But she enjoyed the underlying science. “I like reading mysteries, I like solving puzzles,” she said.

She found a mentor, Frederic Troy, a biochemistry and molecular medicine professor. Bassler was initially dismayed when he assigned her to work with bacteria, but soon changed her mind. Working on her doctorate at Johns Hopkins University, in Baltimore, Bassler found bacteria not just drifting around, but swimming directly to complex sugars to adhere and eat them.

Her road-to-Damascus moment came at a lecture by geneticist Michael Silverman for the Office of Naval Research. (The ONR was funding the Johns Hopkins research about bacteria that adhere to surfaces.) Silverman talked about his work at the Agouron Institute with a marine bacterium that shows bioluminescence — glows — but only when joined by others.

“If there’s just one bacterium, or a few, there’s no bioluminescence,” Bassler said. “But when enough of them get together, they glow collectively.”

After Silverman’s lecture, Bassler rushed up to him and insisted he take her on as an assistant at Agouron in Pasadena, CA. That took her off the beaten track to “a tiny, obscure institute with no reputation,” but one where she could work with Silverman to tease out how the bacteria could work in concert.

Silverman had discovered quorum sensing — bacteria communicating with each other chemically to know when enough of them were present to take an action.

The downside of cooperation: “It means they work together,” Bassler said. “That is, they work together to kill you.”Oftentimes, what bacteria are doing collectively is attacking a plant or an animal, spreading a design.

Of course, some bacteria also perform helpful functions. The heart of Bassler’s research is learning how to identify and eventually manipulate or block their chemical signals, which Silverman termed “autoinducers.”

“It’s like the command-and-control system in the armed force,” Bassler said. “If there’s only a few bacteria, they know not to attempt an action because they’ll just waste energy. But when a quorum is present, they pick up the chemical signals and act together. If we can interfere so that they can’t pick up the chemical signals, they won’t know to take action.”

These findings come at a time when many antibiotics are old and widely used, perhaps overused, with some pathogens displaying increasing resistance to them. Interrupting the autoinducers offers an alternative way to fight pathogens.

Changing minds (2): “Scientists have this stereotype of being nerdy, awkward, uncommunicative,” Bassler said. “My work is about communication, so it would be pretty sad if I couldn’t talk about it.”

Fifth-year graduate student Amanda Hurley said Bassler’s passion for science and ability to explain it clearly “is what drew us all here.” While the professor pushes her lab assistants, “what she doesn’t know is that we like it,” Hurley said.

“Most of our experiments don’t succeed,” Bassler said. “That shows us that we’re thinking too narrowly.”

She feels privileged to be in a place “where we can live in our minds, thinking about things that could change the world,” she said. Of the 18 people in her lab, half are Americans but the rest come from all over. She expects them to continue to spread the research and its results.

Impact of the work: “It takes 10 years to develop a new medicine, and this field has only been around for 20,” Bassler said, adding that she expects to start seeing products soon. One of the most promising areas is the project Hurley has been working on to suppress a pathogen that causes cholera, “which could have a big impact in the developing world,” Bassler said.

Another promising project targets Pseudomonas aeruginosa, which is responsible for a large portion of opportunistic human infections, in hospitals and elsewhere, Bassler said. It especially infects cystic fibrosis patients and others with compromised immune systems, she said.

Changing minds (3): “As you may know, New Jersey doesn’t have a very good image,” Bassler said. Though grateful for the Princeton job offer, Bassler admitted it crossed her mind that “people don’t move from California to New Jersey.” But now, “I love this state. I was surprised at how green and lush it is,” packed with activities outdoors and in, as well as close to New York, she said. “I would love to be this state’s ambassador.”