Do Bacteria Communicate?

V

valich

Registered Senior Member
"Bacteria are a bit like an army going into battle," said Dr. Paul Williams, professor of molecular biology at the center at Nottingham University. "Only when they've got strength in numbers do they tell their troops to start firing."

The thinking is that if bacterial communication can be interrupted, the microbes might be incapacitated before doing any damage. And by not killing off the bacteria, they won't have the Darwinian opportunity to evolve into resistant strains.
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http://www.msnbc.msn.com/id/16911930/

They're saying thousands of scientists are now working in this field, called "quorum sensing research." In order for us to solve the bacterial pathogen problem with antibiotics "we have to be more clever than the bacteria." What is bacterial communication?
 
I've heard of this. They have evolved chemical signals that allow them to act as a unit.
 
spidergoat said:
I've heard of this. They have evolved chemical signals that allow them to act as a unit.
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Yeah, just like humans, they have emotions. If we figure out which chemicals have specific side effects on the unit then we can organize the bacteria in way which is beneficial.
 
Hey. This all sounds like SciFi to me. Yet they say thousands of scientists? Who are they? I think this reporter's got his wires crossed.
 
valich said:
Hey. This all sounds like SciFi to me. Yet they say thousands of scientists? Who are they? I think this reporter's got his wires crossed.
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Quorum sensing is a big field in microbiology and cell biology. If you had any knowledge there at all you would know that. In many cases bacteria produce homoserine lactones (although other compounds have also been identified) which can diffuse to other bacteria and be sensed with certain receptors subsequently trigerring cellular responses (mostly on the transcriptional level).
Quorum sensing is for instance involved in biofilm or fruiting body formation.
Specifically in certain pathogens a high concentration of this signal (indicating a high amount of cells) will trigger virulence. That way they only start becoming pathogenic if enough of them are there.
Other examples are regulation of luciferase production and so on.
 
No I do not have any knowledge in this area at all, but yes I should. That's why I posted it. I am very content to say that there is a lot that I do not know. Thanks a lot.

"Quorum sensing was first discovered in two species of bioluminescent marine bacteria, Vibrio fischeri and V. harveyi. Both of these glow-in-the-dark organisms produce light only when their quorum-sensing ability notifies them that they have reached a high cell density. They then manufacture luciferase....No one has yet figured out what advantage it derives from emitting light.

Bacteria alert one another to their presence by releasing chemical molecules known as autoinducers. When a chemical of this type becomes sufficiently concentrated in the environment (for example, in an organ such as the lungs or intestinal tract), bacteria that are sensitive to it respond by turning on genes that regulate the production of certain proteins. The newly manufactured proteins, in turn, affect the behavior of the bacteria, which take advantage of one another's presence in their efforts to survive and proliferate." http://www.findarticles.com/p/articles/mi_m1134/is_4_110/ai_74693738

Not really "communication," "appears to follow a circadian rhythm" - like stimulus-response: reaches a critical level then activates.
 
Apart from the zoomorphic vector, are there parallels with pheromone signalling in ant colonies?
 
Bacteria regularly exchange bits and pieces of their plasmids, which is why they do so well.
 
zenbabelfish said:
Apart from the zoomorphic vector, are there parallels with pheromone signalling in ant colonies?
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In part. Bactera, especially those forming superstructures as fruiting body, can be chemotactic to each other. This has similarities to how ants follow their trails. The components and mechanisms are very different though.
 
Swarm intelligence: a population of organisms that interact locally with one another and with their environment. Although there is normally no centralized control structure dictating how individual agents should behave, local interactions between individuals often lead to the emergence of global behavior. Examples include ant colonies, bird flocking, animal herding, bacteria molding and fish schooling.
"Ants: swarm intelligence" http://www.answersingenesis.org/creation/v24/i1/ants.asp
www.cis.upenn.edu/~cse391/cse391_2005/presentations/Forster.ppt
"To Bee or Not To Bee: A Comparative Study in Swarm Intelligence" http://www.cs.unimaas.nl/pubs/theses/master/master_Nyree_Lemmens.pdf

"Microbial intelligence, or bacterial intelligence, is the intelligence shown by microorganisms. It may be defined as complex adaptive behaviour shown by single cells, also as altruistic and/or cooperative behavior between like or unlike cells mediated by chemical signalling that induces physiological or behavioral changes in cells and influences colony structures. Complex cells, like protozoa or algae, show remarkable abilities to organise themselves in changing circumstances and even bacteria, which show primitive behavior as isolated organisms, can display more sophisticated responses when they group their activity within a colony. The study of bacterial biofilms has only really kicked off in the last 15 years due to advances in equipment and interest in the field:
- The formation of biofilms requires joint decision by the whole colony
- If there is lesser food available to the colony, the bacteria organise themselves in such a way so as to maximise nutrient availability
- Bacteria reorganise themselves under antibiotic stress
- Sharing of certain genes (such as genes coding antibiotic ressistance) with the whole colony.
- The habitus of Slime mould
http://en.wikipedia.org/wiki/Microbial_intelligence

This one I don't know?:
"Epidinium, a rumen microbe in cattle, possesses something with the appearance of a brain. This is the motorium, and in electromicrographs it shows itself to have something in common with neuronal organization. The motorium features a small loop which encircles the mouth-like stoma through which food particles are ingested." http://www.brianjford.com/04-12-ingens.pdf

Foundation of Cognition- Genome Plasticity and Bacterial Intelligence
http://star.tau.ac.il/~eshel/bacterial_linguistic.html
"Bacterial Communities: A Microbiological Model for Swarm Intelligence" (quorum-sensing, chemotactic signaling and plasmid exchange)
http://star.tau.ac.il/~eshel/papers/Trends-published.pdf

Not verified, but:
Altruism: "some strains of E. coli commit suicide when infected by a virus, thereby protecting their bacterial neighbors from infection."

"Bacteria in stromatolites self-organise and manage to create a large working community even though no single bacterium is in charge....they share genetic information across species" http://news.bbc.co.uk/1/hi/sci/tech/1542539.stm
 
CharonZ said:
In part. Bactera, especially those forming superstructures as fruiting body, can be chemotactic to each other. This has similarities to how ants follow their trails. The components and mechanisms are very different though.
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Thanks CharonZ,
I would also refer to the American Fire Ant Solenopsis invicta, a colony is described by Wilson (2001) as: "an assembly of workers so tightly knit around the mother queen as to act as a single, well-coordinated entity."
The expressed products of the Gp-9 gene act as a mechanism in the control pathways of social behaviour affecting the level of colony queen:worker ratio (Ridley 2001). A female ant either becomes a queen, soldier or worker depending on the food and chemical stimuli received as a larva; however sometimes alates are produced that fly off to start new colonies.

I introduce this to enquire if there are similar mechanism in bacteria, and if so, whether the equivalent of 'alates' are produced.

I guess I'm looking at the idea that in a stable environment without mutation evolution would continue through polymorphism and allometry and the establishment of new populations.
 
Polymorphism: Poly means "many; morph, as in morphology, means the physical appearance or traits of the body of the organism, or the phenotype expression of the genotype.

Allometry means the relative growth of a part of the organism, such as a limb, compared to the entire organism.

Evolution is a process that occurs from mutations. Polymorphs are separate traits. Allometry refers to a distinction in the relative growth of parts. These are all unrelated. New populations can be established without any of the above.
 
*edit, this was posted before I read all the replies...silly me. But Bonnie Bassler is leading the way in this research, link below.

This research is real. It is lead by a scientist at Princeton, and is potentially leading to a way to inhibit the chemical receptors for the communication molecule as a form of disease treatment. Very interesting.

Apparently the compound is very highly conserved among bacteria, so it may inhibit helpful ones.

This is the scientist at Princeton, who I saw on Discovery channel:
http://www.molbio2.princeton.edu/index.php?option=content&task=view&id=27
 
I introduce this to enquire if there are similar mechanism in bacteria, and if so, whether the equivalent of 'alates' are produced.
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Under nutrient limitation myxobacteria undergo an interesting kind of cooperative behavior. They aggregate and a number of them turn into myxospores. The spores can endure stress but do not proliferate. More interestingly though a number of other cells "sacrifice" themselves by building fruiting bodies in which the spores are stored. Thus, only a subset, the spores, actually survives. This process has to be coordinated between cells, since if all cells form the fruiting body, there would be no survivors. The precise regulatory mechanism is not clear yet, but it is believed that a synthesized peptide is at least part of this regualtory cascade.

This brings me to the second point:
Apparently the compound is very highly conserved among bacteria, so it may inhibit helpful ones.
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Actually the mechanisms are widely spread, but not highly conserved. At the moment at least three major classes are known (AHL, peptides, LuxS-autoinducer type 2) and more are likely to be found. Most of the early works involved in quorum sensing was almost entirely focussed on homoserine lactones (AHL).

And as a sidenote: since quorum sensing research started in the 90s roughly 100 papers per year were being published on this topic. As such it is hard to identify any "leading lab". Especially as most are focussing on specific aspects of this very broad topic.
 
A polymorph is one of several possible characteristic traits within a population of species caused by the recombination of alleles; such as blond hair, brown hair, black hair, red hair. A morphological characteristic trait that is more advantageous will tend to increase while those that are not will tend to decrease. The classic study of this, often used in courses, is the different wing colors of the peppered moth. During the Industrial Revolution in England white morphs of the peppered moth decreased because they became easier prey to find against the black soot that blanketed the region from all the pollution. Consequently, the black morph variety increased. Today, now that there is far less pollution, the trend reversed. It's all about advantageous allele frequency.
 
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