A Biologist's Listening Guide to Bacteria Every young scientist dreams of doing an experiment that changes the world. A remarkable biologist at Princeton University has done just that. Bonnie Bassler's discovery about how bacteria talk to one another has led to a whole new field of research -- and maybe someday drugs that would be effective against all bacteria.
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A Biologist's Listening Guide to Bacteria

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A Biologist's Listening Guide to Bacteria

A Biologist's Listening Guide to Bacteria

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From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel.

Every young scientist dreams of doing an experiment that changes the world. Well, a remarkable biologist at Princeton University has done just that.

Bonnie Bassler's discovery about how bacteria talk to one another has led to a whole new field of research, and it may someday lead to drugs that would be effective against all bacteria.

As NPR's Richard Harris reports, the science isn't the only thing that makes her remarkable.

RICHARD HARRIS: Every weekday at 5:42 AM, Bonnie Bassler's alarm clock goes off. She pushes a remote control button to start her coffee maker and she puts on some gym clothes and heads to the Y.

(Soundbite of music)

Unidentified Woman: (Singing) Well, I…

Professor BONNIE BASSLER (Molecular Biology, Princeton University): Four more, three. That looks good. Turn it over. And, go.

HARRIS: Forget for a moment that she won the MacArthur genius award a few years ago, that she's just been elected to the august National Academy of Sciences, or that the Howard Hughes Medical Institute has lavished more than $1 million on her lab this past year.

Prof. BASSLER: And out.

HARRIS: The same drive that made her a noted professor at Princeton University brings her here every morning at an ungodly hour to teach aerobics.

Prof. BASSLER: Lift up, lift up. Relax your shoulders, hold your elbows high. Eight, seven…okay, we should do a hard one to try to show off.

(Soundbite of crowd chatter)

Prof. BASSLER: Where you going Diane? You just got here.

HARRIS: For an hour and a quarter, under a mop of dark curls, she puts a doting class through its paces. Bassler is 44 years old and has been doing this for half her life.

Kathie Wilcox has been coming to this class for the past five years.

Ms. KATHIE WILCOX: Bonnie's a lot of fun and she makes the time go very quickly, although we're huffing and puffing and getting a good workout. So…

HARRIS: So she's huffing and puffing and working and talking.

Ms. WILCOX: Exactly. Is that fair or what, on top of everything else?

(Soundbite of laughter)

Prof. BASSLER: And press. Keep those knees…

HARRIS: People in the world of science have also been dazzled and left gasping for breath in Bonnie Bassler's presence. But her story is not simply one of super achiever, as she explains as we walk between the buildings on the Princeton campus.

Prof. BASSLER: The Frank Geary building. It's really beautiful. It's going to be the new library.

HARRIS: How did you end up here?

(Soundbite of laughter)

Prof. BASSLER: It's the only job interview I had. Yeah, I was looking for a job and sent out all these applications, and Princeton bit. It's really neat the way that worked out for me, you know, because I've been incredibly happy here. God.

HARRIS: We head upstairs in the Lewis Thomas biology building, toward a large suite of labs that she now runs.

Prof. BASSLER: Okay, you're going up to the lower life-forms floor.

Unidentified Man: Hey.

Prof. BASSLER: (Unintelligible) look at you. Being industrious.

HARRIS: In her lab, 14 young scientists - an even mix of men and women - are buzzing about, determined to unlock the secrets of how bacteria talk to one another.

Prof. BASSLER: What's great about bacteria is you have a surprise every day waiting for you because they're so fast. Something happens overnight. They all grow.

So you run in here and you open that incubator and you take out those plates every morning, and there's colonies when there shouldn't be, or there aren't colonies when they should be, or they're glowing when they shouldn't be. And, you know, the first word out of your mouth is a cuss word.

And then you're like, I hate this. This is awful. How could this not work? And the next thing is - this is what we are - It's like, well, maybe I could try this. Well, maybe I could try…

Like, we must be stupid. You know, we just come in day after day after day for this torture. But then when you get the good day, where you really figure something out - like the structure of a molecule or you get the gene you've been looking for - those days last a long time.

HARRIS: Bassler has had plenty of those blissful days. In fact, this whole field basically didn't even exist before Bonnie Bassler came along. Now, more than 100 labs around the world are working on it.

She says she simply stumbled into it. One day when she was getting her Ph.D., she came across a reclusive scientist named Mike Silverman.

Prof. BASSLER: I happened to hear like one of the only talks he ever gave in 10 years because he never traveled much. He was sort of a gentleman scientist.

HARRIS: She says she barely understood the talk since Silverman was a geneticist and she was a chemist.

But this much she got: Silverman said individuals from one species of glow-in-the-dark bacteria appeared to be talking to one another.

Prof. BASSLER: I remember sitting there thinking, get out of here. They're bacteria. They can't do that. Which, of course, is what we all thought. And then I remember thinking, just thinking to myself like, he thinks about them like they're little personalities and he's found this amazing thing. And I just have to work on that.

HARRIS: So she says she rushed right up to the podium after his talk and begged for a job at his tiny institute. He said yes, so she spent the next four years there. And she figured out how these bacteria talk to one another: they use not just one but two chemical signals.

Prof. BASSLER: So this is my idea of science.

(Soundbite of door opening, hitting wall)

HARRIS: We head into a pitch-black room with a rack of Petri dishes so she can demonstrate this bacteria's hidden talent.

(Soundbite of rattling)

Prof. BASSLER: Tell me when you can see it.

HARRIS: I see…I see a light glow.

Prof. BASSLER: Right. Your eyes will get better. My eyes adjust right away because I've spent almost my entire adult life in a room like this, right. That's why they glow like that.

This is how this whole field started, was this little - you're just looking at this bacterium, which is this marine bacterium.

HARRIS: It turns out that when one of these bacteria is all alone, it doesn't glow. After all, that would be a waste of effort because nothing could ever see such a tiny amount of light. But it does send out chemical signals that say hey, I'm here. And it listens back for other bacteria sending the same signal.

When enough bacteria are doing this, they know they have a quorum. And all of a sudden, they light up and do all sorts of other things to act in concert, like a super-organism.

Prof. BASSLER: So they turn on and off 100 different genes, you know, to let them turn off behaviors that are good when you're alone and turn on behaviors that are good when you're a community. And then for actually reasons we don't exactly understand, this enzyme that makes this beautiful blue light is one of those genes that turns on.

Mr. HARRIS: At first, the scientific reaction that these luminescent bacteria use chemicals to talk to each other was big whoop.

But the molecular biology department at Princeton was willing to bet that there was more to the story.

Tom Silhavy was head of the search committee at Princeton that hired Bonnie Bassler 12 years ago. He says he just had a feeling.

Mr. TOM SILHAVY (Molecular Biology Department, Princeton University): It's hard to know how a newly hired faculty member is going to do in their first really independent position, so you have to trust your instincts a little bit, you know?

HARRIS: She certainly proved her mettle.

Mr. SILHAVY: Yes. She's now more famous than all the rest of us combined, actually.

(Soundbite of laughter)

HARRIS: Bassler surprised even herself.

Prof. BASSLER: The goal of scientists is you hope the thing that you're working on is bigger than whatever you're pipetting into that tube at that moment.

We always knew we were working on something bigger than bioluminescence, but we didn't think it was going to be what it turned out to be. It's just been so much better.

HARRIS: That's because once Bassler got to Princeton, she started asking whether this chemical communication was just the trick of this one species, Vibrio harveyi. It turned out that communication is universal among all bacteria, including the nasty ones.

Prof. BASSLER: Melissa Miller, a graduate student in the lab, went on to show that cholera has a circuit like Vibrio harveyi's. And what it does, I mean, it doesn't make light. It makes toxins, and so that's what it does as a group.

So like they can't make you sick if they're just acting as one. You know, but if they wait and they launch their attack together, it's fantastic.

HARRIS: And what's more, Bassler came to realize that bacteria don't just talk to others of the same kind. One chemical, she discovered, serves as a universal language that all species of bacteria can understand. So all bacteria can talk to all other bacteria.

What's more, she realized that since bacteria evolved first, they must have invented chemical communication, which is now used to organize all giant collections of cells into organisms.

Prof. BASSLER: This is what happens in your body, is that it's all this chemical communication. You know, we call them hormones, right? And your kidney cells don't get mixed up with your heart cells because there's these different languages. And that's exactly what this bacterium is doing.

HARRIS: In an odd way, her life is also based on this strategy. She is an individual, but also part of a larger collective. Think of her aerobics class.

Prof. BASSLER: As you saw, we're practically the Rockettes.

HARRIS: Okay, not a great example. But in her lab, Bassler really is not just a lone operator, but is part of what you can think of as an intellectual super-organism.

Prof. BASSLER: Who wants to talk to me about science?

HARRIS: Bassler constantly wanders through her labs, touching base with her young and energetic crew.

On this day, Mike Fetterley(ph) pipes up.

Mr. MIKE FETTERLEY (Student): We've been thinking we need to make a protein fusion to Sag A(ph) and see…

Prof. BASSLER: Everybody's lab takes on the personality of the adviser, right? And so the people that come to me are these fun-loving, you know, excited, honest and really hard-working people that are totally neurotic. Right? And so like, everybody - as soon as they do a good experiment - their first thought in this lab is, that must be wrong. I must have screwed it up. What did I do wrong? Self doubt. And I, you know, if I'm going to be, like, honest, that's who I am. And it's a thing that drives me. It's a terrible part of my personality, this nothing's ever good enough. I'm not smart enough. This is part of my mantra. You know, I need to work harder. And if I were only smarter, I could help them through their struggle better.

HARRIS: You say you're driven insecurity, yet you've, you know, you won the MacArthur Award, Lily Prize, Howard Hughes scholar. You were just elected to the National Academy of Sciences. Doesn't any of that count?

Prof. BASSLER: Not really.

(Soundbite of laughter)

HARRIS: Well, she says, sometimes it's hard to see which ideas are really hers. She grudgingly will admit that she is a good scientist, and she is setting the course for her group's future. They are now trying to find some way to interfere with the universal language of bacteria, to prevent them from ganging up against us. That could lead to a super antibiotic.

Prof. BASSLER: But it would be fantastic if like out of this crazy, glow-in-the-dark bacteria and they came out of the ocean - if, you know, something like really, really good, like a new kind of antibiotic came out of this guy.

HARRIS: And, she hastens to add, it would be a collective victory, not simply her own.

Richard Harris, NPR News.

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