Cracking the Code of Bacterial Communication

TEDChris writes "Microbiologist Bonnie Bassler explains her discovery of 'quorum sensing' — the amazing ability of bacteria to communicate with each other and coordinate attack strategies (video). By cracking the communication code, she has opened up potential for a new class of drugs tackling microbial diseases. The talk got a massive standing ovation at this year's TED and has just been posted. To quote one commenter: 'This is by far the most inspiring, amazing, and far-reaching talk I've seen in a very long time.'"

Comments

I love TED.

[QuantumG]

The first 10 seconds after the obligatory TED intro spam she says something stupid - "Bacteria are the oldest organisms on the planet", Oh Really? I guess "Archaea" are just called that for fun.

And after 15 minutes of completely horrid microbiology 101, which, btw, she claims her group she discovered, she finally gets to the "please give us grant money" pitch. Quorum sensing blocking drugs may have theraputic efforts. Wooo, ya don't say. But the silliest thing is that she suggests these might replace anti-biotics. Cause, apparently, stopping pathogenic bacteria from enacting their "we're in the majority now" payload is just as good as killing them. Nevermind that eventually these drugs will wear off, and that population of bacteria won't be getting any smaller.. and that the whole mechanism of our immune system is based on detecting the harm that pathogens cause.. just keep taking the drug, forever, and you'll never get the symptoms that your immune system needs to tell it to fight off the infection. Problem solved once and for all. But.. once and for all!!

The drug companies will love it though.

Re:I love TED.

[interkin3tic]

Bacteria are the oldest organisms on the planet", Oh Really? I guess "Archaea" are just called that for fun.

I'm certain she knows all the stuff you just mentioned, maybe she even teaches a "microbiology 101" and covers that.

Sounds like she was talking to a crowd that wouldn't know eubacteria from archaea. Kind of like if an entomologist uses "bugs" to refer to insects and arachnids. She was obviously "dumbing it down" for a specific crowd. So she's not being 100% accurate in the details that the audience won't remember, big deal. Maybe she went too far, it's debatable, but her talk sounds like it went over well with the audience and was a success. I say good job, focusing too much on trivial details is a good way to ensure ineffective communication.

Re:I love TED.

[coolsnowmen]

Why are you so quick to criticize? Ever researcher wants more money, otherwise they can't continue doing research. duh.

"Bacteria are the oldest organisms on the planet", Oh Really? I guess "Archaea" are just called that for fun.

Classification changes though, when I took biology we didn't have a 3 domain system, and Archaea were considered a sub section of Bacteria. I know this is based on newer theories of their evolutionary history, but really, this history had nothing to her research.

Forget about Antibiotics. As she said, your body needs bacteria to live, so better understanding how to control and perhaps even help bacteria do their job inside you is important.

Wouldn't it be nice to reduce malnourishment problems if you could give impoverished people really efficient bacteria?

Wouldn't it be easier than a tummy tuck if you just gave someone lazy bacteria ?

I think it is interesting, but it is a free country and you are welcome to spit on what she cares about.

Re:I love TED.

[Anonymous Coward]

Just because you aren't using the "scientific" definition doesn't mean you aren't speaking correctly.

Especially when the scientific definition co-opted a preexisting word.

Re:I love TED.

[calcapt]

The method of anti-bacterial action you say she presents is precisely how bacteriostatic antibiotics work, by inhibiting growth of bacterial populations; the point is to give your immune system a chance to catch up with the bugs, making them more manageable. In that sense, it's not a stretch that drugs that imitate quorum sensing signals could replace antibiotics. At the very least, more drug options would be provided. This would be important when the bugs become resistant to our existing drugs.

Re:I love TED.

[Anonymous Coward]

She doesn't claim that her group discovered microbiology; she claims that all science research is done by underlings in that age range. Which is pretty accurate; young people in academia do the bulk of the work and get to be the fifth author on papers.

Re:I love TED.

[bugnuts]

just keep taking the drug, forever, and you'll never get the symptoms that your immune system needs to tell it to fight off the infection

You do have a good point... delaying virulence while the bacterium continues reproducing is probably bad because if you ever stop the drugs, you get a much worse infection. But I would bet your body will still know the bacteria are there, before they reach critical mass. It would still detect the proteins of the bacterium cell walls.

You could go the other direction: on exposure to something, you could get a shot of the receptor that caused virulence. The bacterium would, possibly, burn itself out before reaching critical mass or release useless pathogens before it was bound to a host's cell (e.g.).

This type of treatment might be able to slow down infection, giving your system time to fight it off. It might be useful for, say, battlefield injuries to slow the nasty infection while they drag your limp body to a medic, despite the fact you'll have to fight off more of the pathogen.

It would also be really useful as an on-off switch for a living glow-stick :-)

Re:I love TED.

[Anonymous Coward]

based on your comments, you must be taking microbiology 101 right now. you are clearly neither an actual microbiologist nor an immunologist, and it would be best if you don't try to critique things about which you have no clue.

bonnie bassler was one of the discoverers and is a lead researcher of quorum sensing. try a google scholar search for "bassler quorum sensing."

"the whole mechanism of our immune system is based on detecting the harm that pathogens cause". what are you talking about? do you know anything about T cells, B cells, or toll-like receptors? I didn't think so.

given how the immune system actually works, blocking virulence is a legitimate strategy for antibiotics, not least because it could exert less selective pressure on the microbes. while virulence was blocked, your immune system would be able to recognize and eliminate the bacteria.

bonnie bassler doesn't need grant money. she's hhmi (http://www.hhmi.org/research/investigators/bassler_bio.html) and has a macarthur "genius" fellowship, both of which are essentially blank checks for top-flight researchers. I'm sure you already knew that though.

Re:I love TED.

[Opportunist]

Or, in a nutshell:

There is money in curing a disease.
But there is more money in treating it.

Re:I love TED.

[QuantumG]

Actually, no, they don't do that. Maybe you should set aside your biases and listen. I admit it's hard to hear what she's saying through the rudimentary level of discussion.

Re:I love TED.

[Anonymous Coward]

Why are you so quick to criticize? Ever researcher wants more money, otherwise they can't continue doing research. duh.

There's a difference between applying for money and spamming for it. Poor researchers can and do cross the line, substituting new results with repetitive marketing.

Re:I love TED.

[Anonymous Coward]

Troll..

1) You are nit picking about the bacteria vs archaea thing. It's not relevant to the speech.

2) Contrary to your claims she never mentioned money or funding in any way.

3) The whole POINT of the lecture was about bacterial behavior based on the quorum. If your sick from some bacteria, are you going to say "no doctor I will only take treatments that kill the bacteria, blocking the quorum isn't good enough"? Well maybe you should because you are a troll.

4) How do you know the quorum blocking drugs will wear off? That topic wasn't discussed in the video.

Re:I love TED.

[Quothz]

1) You are nit picking about the bacteria vs archaea thing. It's not relevant to the speech.

And hooray for the nitpickers, says I! The tone of the OP may've been sour, but I'd never heard of archaea before in my life. I learned a little something from the discussion that I wouldn't otherwise have, thanks to a nitpicker.

Re:I love TED.

[digitalderbs]

I'm suspicious too. I learned about quorum sensing, and its possible pharmaceutical appeal, in college ten years ago. And these ideas have been around for much longer than that.

I've never heard of TED, as an active medical researcher (NIH). I've never seen a standing ovation, including four lectures from Nobel laureats (one of which was charismatic).

This strikes me as an insidious and tawdry advertisement. The fact this was posted by 'TEDChris' is confirmation. At least admit that it is so.

Re:I love TED.

[Anonymous Coward]

Why are you so quick to criticize?

because he's an obnoxious asshole with women issues, who likes sneering at people to try and make himself feel less inferior. Presumably he wasn't to popular with girls at school or something.

Re:I love TED.

[Anonymous Coward]

Let's see... hmm... take the word of some random guy on Slashdot, or someone who has a MacArthur fellowship and her own lab at Princeton.

Tough call, that. Fortunately, (ahem), I can be bribed.

Re:I love TED.

[QuantumG]

Heh, TED is a conference for rich people and washed out movie stars who wanna smooze with scientists. The price of admission is this kind of pandering.

Re:I love TED.

[QuantumG]

Or you could watch the video and form your own opinion.. that might involve thinking though, so perhaps you shouldn't try it.

Re:I love TED.

[Anonymous Coward]

I did WTFV. Other than the bit about not mentioning Archaea, which I agree struck a dissonant note, I didn't see anything wrong, other than the fact that I'm not banging that chick.

Re:I love TED.

[robmarms]

AHAHAHAHA, the guy clearly can not formulate an argument which lacks biased and sexist undertones. Really though, this article has to be a tad off about the 'invention' of quorum sensing... We've all known for a while that there is an amplification and synchronization event among bacteria, it was just a matter of how.

Re:I love TED.

[Tsu Dho Nimh]

Quorum sensing blocking drugs may have theraputic efforts. Wooo, ya don't say. But the silliest thing is that she suggests these might replace anti-biotics. Cause, apparently, stopping pathogenic bacteria from enacting their "we're in the majority now" payload is just as good as killing them.

Stopping them from making the biofilm or communicating IS as good as killing them, because it leaves them vulnerable to the body's defenses that they would be invulnerable to. It's a form of bacteriostatic drug like the ones given for anthrax, rickettsia (Rocky Mountain Spotted Fever), bubonic plague, etc. Those are bacteria you don't want to kill quickly.

Re:I love TED.

[mr_mischief]

Better yet, if you can detect a specific dangerous bacterium early and convince it to attack the body before it actually has an effective population maybe the body's immune system will have an easy time of it.

Re:I love TED.

[Cyberax]

Uhm...

We already have bacterial treatments for malnourishment caused by disbateriosis: http://en.wikipedia.org/wiki/Probiotics

Re:I love TED.

[nobodylocalhost]

I don't have a problem with treating a disease and not curing it if there are no long term biological negative effects. This is because generally speaking it is not a good idea to make different strains of bacteria simply extinct. Case and point, we have virtually made smallpox extinct, but since governmental agencies kept samples and certain governments do collapse, these samples got sold and could be made into biological weapons. The populace regard smallpox as extinct, thus we didn't have immunization against it, and the disease became much more effective as a weapon than it would've before it was cured.

Re:I love TED.

[calcapt]

Uh, I'm checking notes from my Bacterial Pathogenesis lectures, and they say that YOU'RE wrong. The University of Southern Carolina med school site also has a page of notes on this matter that agrees with what I've learned; this isn't based soley on the TED talk, this is based on what I've learned from prior experience in bacterial pathology.

http://pathmicro.med.sc.edu/mayer/antibiot.htm

"Antibiotics are categorized as bactericidal if they kill the susceptible bacteria or bacteriostatic if they reversibly inhibit the growth of bacteria. In general the use of bactericidal antibiotics is preferred but many factors may dictate the use of a bacteriostatic antibiotic. When a bacteriostatic antibiotic is used the duration of therapy must be sufficient to allow cellular and humoral defense mechanisms to eradicate the bacteria."

Or am I misunderstanding something? Are you a biologist of some sort with experience in the field?

Re:I love TED.

[Foamy]

I have to agree. I learned about quorum sensing and work over a decade ago. To say she "discovered" quorum sensing is utter rubbish. I don't care to read her publication record to find out what she actually discovered, but quorum sensing it was not.

Here's a paper from 1994 for example:

Interchangeability and specificity of components from the quorum-sensing regulatory systems of Vibrio fischeri and Pseudomonas aeruginosa.
Gray KM, Passador L, Iglewski BH, Greenberg EP.
J Bacteriol. 1994 May;176(10):3076-80.

Re:I love TED.

[Anonymous Coward]

But the silliest thing is that she suggests these might replace anti-biotics. Cause, apparently, stopping pathogenic bacteria from enacting their "we're in the majority now" payload is just as good as killing them. Nevermind that eventually these drugs will wear off, and that population of bacteria won't be getting any smaller.. and that the whole mechanism of our immune system is based on detecting the harm that pathogens cause..

Well, then use the false "we're in the majority now" signal to provoke them to act out early, then immune system would smite them before they establish a foothold!

It would be a prophylactic, or early administered medication ("escalators"), to prevent pathogenic bacteria build-up in apparently healthy organisms ... and you were right: drug companies would love it.

Re:I love TED.

[Raffaello]

What makes the method new is that the proposed drugs don't interfere with protein synthesis or bacterial metabolism as ordinary bacteriostatic drugs do, they interfere with intra-species and/or inter-species bacterial communication.

It is this focus on blocking or interfering with bacterial communication, rather than blocking internal metabolic processes (such as protein synthesis) that makes this approach new.

Think of it as an outward extending hierarchy.
I. within an individual organism. this is the realm of traditional bacteriostatic and bactericidal drugs.
II. between organisms of the same specis. this is the realm of intra-species quorum sensing.
III. between organisms of different species. this is the realm of inter-species quorum sensing.

The drugs she is proposing would work in realms II and III.

Re:I love TED.

[rthille]

Not if there is someone else selling a cure...

Re:I love TED.

[coolsnowmen]

You say "um", but science has barely scratched the surface with what can be done with bacteria.

Also, I didn't say the cause was no bacteria, just lazy ones. what if we could make them better? I don't have the answers, but this research doesn't seem pointless to me.

I picked somethings off the top of my head, and I am not a biologist at all. What about using it to encourage or discourage bacteria when breeding it in the lab for a certain purposes (biological engineering) Let us say we are breeding bacteria for some medial use, but that takes time, every hour in culture costs an extra 100$ to pay someone with technical skills to watch it. What if some protein could halve that time? Now this drug can cost less money to bring to market.

If you can't think of uses for research that influences bacteria using the signaling of bacteria with external stimuli, then you just haven't thought hard enough.

Re:I love TED.

[treeves]

Just out of curiosity, why don't you want to kill those particular bacteria quickly?

Re:I love TED.

[Anonymous Coward]

"...the whole mechanism of our immune system is based on detecting the harm that pathogens cause."

I'm not a microbiologist, but I don't think this is the case. The immune system detects and destroys invaders primarily based on their being *different* (e.g foreign proteins on their surfaces), not based on the byproducts of their destructive activity.

Re:I love TED.

[Tsu Dho Nimh]

Just out of curiosity, why don't you want to kill those particular bacteria quickly?

Because it releases toxins from the dead bacteria and can kills the patient. You give bacteriostatic drugs to prevent cell division and let the white blood cells take care of the bacteria at a slower pace.

Re:I love TED.

[Anonymous Coward]

Isn't that what was said?

"You could go the other direction: on exposure to something, you could get a shot of the receptor that caused virulence. The bacterium would, possibly, burn itself out before reaching critical mass or release useless pathogens before it was bound to a host's cell (e.g.)."

Re:I love TED.

[mr_mischief]

That reads as if the bacterial population in question, when it activates to "burn itself out", just becomes ineffective on its own. A major reason quorum sensing is useful to bacteria is that it delays detection by the immune system until there's enough bacteria that the immune system has a difficult time destroying the whole population. Triggering the bacteria to attack before reaching high enough numbers doesn't just weaken their attack. It also gives the immune system a head start of its own because it can react to the released chemicals before they are released all at once at dangerous levels.

Killing household mold

[BadAnalogyGuy]

One of the leading health concerns is household mold and staph. The inhalation of these over years of exposure leaves the body weakened and infected. In very bad cases it can lead to pneumonia and in the worst case staph infections which lead to amputation.

If they can find a way to reduce or eliminate bacteria growth in the home, they are halfway to eliminating disease in Western nations.

Re:Killing household mold

[Cassius Corodes]

And the gateway to an autoimmune pandemic!

Re:Killing household mold

[Renraku]

Mold and staph are both very good at entrenching themselves into their environment. They basically form a base layer that they can attach to, and then they're much harder to get out. A good method of attacking mold or staph colonies would be to find something that breaks up their base layer so that they're exposed to the environment. Unfortunately, you need a chemical that can penetrate porous materials easily, and those chemicals don't tend to do well around the home.

Re:Killing household mold

[Vesvvi]

Bacterial infections aren't even on the radar compared to self-inflicted problems such as obesity.

Re:Killing household mold

[BadAnalogyGuy]

What you are saying would be true if you are only looking at symptoms. Take the common cold for example. You wouldn't say that the viral infection is pretty minor compared to the sneezing and runny nose symptoms, I hope. One is the cause and the other is the symptom. It makes more sense to attack the cause to avoid having to attack symptoms.

Yes, in the short term, the damage has already been inflicted and symptoms do need to be addressed. However, this doesn't preclude us from also attacking with vigor the root cause of many of our modern day afflictions, namely bacteria.

Re:Killing household mold

[MichaelSmith]

Bacterial infections aren't even on the radar compared to self-inflicted problems such as obesity.

In the West, anyway.

Re:Killing household mold

[Vesvvi]

The base layer you're referring to is usually termed a "biofilm", and they are complex, three-dimensional, organized structures of living (and some "hibernating") organisms.

I think the best large-scale analogy to a biofilm would be a rainforest, where there are many levels of depth with complexity that varies depending on where you're looking.

Chemical penetration through that multi-layered structure is extremely complex, and usually substantially slowed. In many cases even potent chemicals such as bleach won't reach the base layers, despite multiple washings with long incubations.

It's not really a problem of being restricted only to "nice" chemicals: we haven't found -any- chemicals that act as a magic bullet. Back when I started research in the field it was thought that quorum sensing might be the cure we were looking for, but it turned out to be much less useful than hoped.


As for the previous comments on Dr. Bassler and her "discoveries", I think people react negatively to exaggerated claims of novelty. If the fault for that those exaggerations lay with TED, then they are being a bit sloppy, but if Bassler herself suggests that she is intellectually dishonest. Her work ~1994 seems to be very highly regarded in establishing the study of quorum sensing, but there are several papers from the years just previous to that which actually discovered it.

Re:Killing household mold

[Vesvvi]

Yes, sorry, I should have included that caveat.
From the CDC:
* Heart disease: 652,091
* Cancer: 559,312
* Stroke (cerebrovascular diseases): 143,579
* Chronic lower respiratory diseases: 130,933
* Accidents (unintentional injuries): 117,809
* Diabetes: 75,119
* Alzheimer's disease: 71,599
* Influenza/Pneumonia: 63,001
* Nephritis, nephrotic syndrome, and nephrosis: 43,901
* Septicemia: 34,136

After looking up the numbers, I must admit that it's closer that I was expecting: perhaps 870k for health-related issues vs 270k for infectious agents. With the current trends, I think we'll see that gap increase.

Re:Killing household mold

[atamido]

Seal up the environment, boil chlorine into the air, and let it sit for a few days. Isn't that what the CDC does?

Re:Killing household mold

[Anonymous Coward]

Bassler's work is very highly regarded in this field, and her work is fascinating and could lead to new medications, drugs, etc. There aren't papers "just previous" to '94; auto inducer 2 (AI-2), one of the major quorum sensing molecules, was originally discovered back in 1970.

Orson Scott Card

[TheEldest]

Didn't Orson Scott Card come up with this in Xenocide?

Re:Orson Scott Card

[calcapt]

I doubt he invented the concept. In the afterward sections of his books, he often talks about how he draws from other sources. I'm pretty sure in one of his books he mentions how he consulted medical workers on plausible scenarios; Card could've simply picked up the idea of communicating via chemicals through such an experience. While the earliest scientific article I can find on quorum sensing, through PubMed and Web of Science, is from 1995, I'm sure the idea of microorganisms communicating through such a mechanism is much older and probably predates Xenocide.

For those who prefer to read

[oldhack]

I read this about bacteria communication as reported in Science News in January:

http://www.sciencenews.org/view/feature/id/39602/title/Team_spirit

Different researchers are interviewed, though.

Where have I heard that before

[gringer]

"Quorum Sensing"... I remember that phrase. It sounds strangely like something we considered putting into our signal transduction paper back in 2004 (published 2006). It was Lisa, not I, who did the reading on quorum sensing, so I can't claim to be well-read in the subject.

http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&cmd=search&term=cashin+goldsack+hall

Re:Where have I heard that before

[Anonymous Coward]

Wow, karma-whoring your journal article on Slashdot! It sounds strangely like something I considered doing back in 2004...

How about speeding up quorum sensing?

[Anonymous Coward]

I suspect the antibody response of the body is in some way related to the detected activity of bacteria. Would an 'induced quorum sense' at an early stage of infection lead to a limited total bacteria activity, with a strong enough antibody response?

Wonk flamefest

[benjfowler]

From the point of view of an outsider looking in, it looks like this Slashdot story just got bum-rushed by a bunch of brawling microbiologists.

Is there some big long-running all-in slugfest here that we ought to know about?

Re:Wonk flamefest

[lanthar]

Don't you know that many researchers are credit hogs, who eventually rise to the review level and heavily criticize and turn down proposals of those that might criticize their own work? It's the awful truth about scientific research and grant money. It's like a soap opera.

CONSPIRACY THEORISTS!!

[cryophan]

CONSPIRACY THEORISTS!!

started good, ended poorly

[v1]

I found it interesting that she didn't expand on what the actual effects of the quorum drugs were. She just said that we have these quorum suppressors and quorum enhancers and we're going to use them to fix our problems. Why? Why would an enhancer be useful and a suppressor be useful? when? Felt more like "we found a way to meddle with the system and are going to flail our hands wildly and hope something good happens!"

The mouse example was a good illustration of this. After all the setup describing what they did, the conclusion: "the mouse lived" or "the mouse died". Well, THAT demonstrates a good understanding and thorough conclusion now doesn't it? I'd feel a lot better if they acted like they had any idea WHY the mouse lived or died, other than based on what drugs they treated it with. Why did the drugs help? What specific bacterial behaviors were altered?

My wild speculation here is that if you pump a bunch of those quorum signals into a body, you fool the bacteria into believing they are a lot more numerous, and trigger their pathogenic (dangerous/attack) behavior (and thus an accelerated immune system response) before there's enough bacteria present to overcome the immune system. Instead, the immune system has the time to get ramped up and move to action while there's still a low bacterial count, and the bacteria are wiped out. THAT'S the kind of conclusion I was expecting from this presentation. But instead I was sadly disappointed by the almost complete lack of followthrough at the end of what started as a very interesting presentation.

Re:started good, ended poorly

[QuantumG]

Welcome to the modern pharmaceutical industry. We live in the era of "throw shit at the wall and see what sticks" medical treatment. If you find a drug that stops mice from dying when you inject them with the plague (or staph or whatever nasty will get you the most funding this week) then you've done all the basic research you need. Now all you need to do is patent it, find yourself a buyer and they'll start the long death march to a clinical trial, all the while trying to figure out how best to make it for pennies and charge millions.

Re:started good, ended poorly

[Anonymous Coward]

Here's a (text) interview with Bonnie Bassler on TED's blog. She further explains elements of this process. It might answer some questions you may have:

http://blog.ted.com/2009/04/the_secret_soci.php

From the Q&A:

"The bacteria would 'think' they were alone when they are actually in a group. Alone, they don't initiate virulence cascades. So, if the bacteria can't count themselves and thus, can't carry out these group virulence activities that are critical for enabling them to stay in the host, the immune system just gets rid of them."

Re:started good, ended poorly

[v1]

The bacteria would 'think' they were alone when they are actually in a group

That only covers the quorum inhibitors. The presenter made almost zero distinction between the use of boosters and inhibitors. That particular quote discusses the inhibitors. I'm sure the boosters don't work that way. (which is the scenario I was exploring)