# beneficial nematodes



## bbrock (May 20, 2004)

Ed tipped us off to this work in another thread showing a beneficial effect from a presumed parasite:

Here's a link to the abstract of the published work.

http://www3.interscience.wiley.com/cgi- ... 1&SRETRY=0

If anyone has access to this journal, I'd love to get a copy of the paper. Ed posted this link to a popular article on the same study:

http://news.ufl.edu/2004/11/08/helpfulworms/


----------



## edwardsatc (Feb 17, 2004)

Brent,

I have access, but only in hard copy. I can get it and scan it for you on Monday or Tuesday if someone else hasn't come up with it by then.


----------



## Ben_C (Jun 25, 2004)

I e-mailed you the paper.
~B


----------



## rozdaboff (Feb 27, 2005)

This is an incredibly interesting area of microbiology (well, at least to me :lol: ). While a lot of research has been performed on how parasites, bacteria, fungi and viruses cause disease - there has been limited investigation looking into potentially beneficial sequelae caused by infection. This is particularly likely in ubiquitous infections that are long-lasting (some for the lifetime of the host) that cause limited disease.

This isn't amphibian related - but there was an interesting paper in Nature this past year that demonstrated that mice that were infected with a herpesvirus were resistant to infection by two pathogenic bacteria. The resistance was not due to a specific response against these two organisms - but instead an increased basal level of innate immunity.

_Barton, E. S., D. W. White, J. S. Cathelyn, K. A. Brett-McClellan, M. Engle, M. S. Diamond, V. L. Miller, and H. W. Virgin. 2007. Herpesvirus latency confers symbiotic protection from bacterial infection. Nature 447:326-329._

I think that cases like these will become less "the exception" and more "the norm" as more research is performed.


----------



## Roadrunner (Mar 6, 2004)

Look at the bacteria their looking into to fend off chytrid which was found on some salamanders unaffected by chytrid.
The link is somewhere in sci and conservation section.


----------



## Ed (Sep 19, 2004)

The interactions between the different parasites is also a field that has been relatively ignored until now. 

I lost the link as I had to get something for my wife but in some amphibians that have multiple species of some of the intestional nematodes infecting them, the total population was limited competition in the group and the computer autoshut down. If I get a chance I'll have to look for it. 

Ed


----------



## bbrock (May 20, 2004)

I agree it is fascinating, but not at all unexpected. We know that ecology operates on many scales. Each organism can be considered as an ecosystem unto itself. Within the last couple years, Nat. Geographic had a cool article on human symbionts. A couple interesting points were that some research suggests that there are more non-human cells in the human body than human cells, and that a diversity of microbes in the body appears to help prevent any one microbe from taking over and causing disease. Again, that's not unexpected because it is simply an example of what is already known about community ecology at a different scale.

Oh, and thanks for the paper Ben!


----------



## npaull (May 8, 2005)

> some research suggests that there are more non-human cells in the human body than human cells, and that a diversity of microbes in the body appears to help prevent any one microbe from taking over and causing disease


Just to be technically correct, organisms in the GI tract (which account for non-human cells outnumbering human cells "in" the human body) are NOT actually inside the human body, but rather surrounded by special human membranes while being quite distinctly outside the body... those spaces truly inside the body (in the vasculature, etc) are, as a general rule, sterile.

The second part of the statement is definitely true; and it can be quite disastrous to disrupt this normal flora. It is well known in medicine that infections of Clostridium difficile can occur subsequent to use of the antibiotic clindamycin, which can disrupt gut flora.

There is also mounting evidence that a rise in allergic and autoimmune disease in western culture may be related to increasing cleanliness and a collective neurosis about harmless bacteria... "protecting" our immune systems from dealing with simple problems to the point that they freak out inappropriately when facing ubiquitous antigens.

Let your kids play in dirt.


----------



## donstr (Jun 21, 2007)

npaull said:


> There is also mounting evidence that a rise in allergic and autoimmune disease in western culture may be related to increasing cleanliness and a collective neurosis about harmless bacteria... "protecting" our immune systems from dealing with simple problems to the point that they freak out inappropriately when facing ubiquitous antigens.
> 
> Let your kids play in dirt.


For more on this read Good Germs, Bad Germs by Jessica Snyder Sachs.
Excellent book!


----------



## bbrock (May 20, 2004)

npaull said:


> Just to be technically correct, organisms in the GI tract (which account for non-human cells outnumbering human cells "in" the human body) are NOT actually inside the human body, but rather surrounded by special human membranes while being quite distinctly outside the body... those spaces truly inside the body (in the vasculature, etc) are, as a general rule, sterile.


I should read the article again, but I thought they mentioned finding non-human cells within the interstitial space between human cells. I thought the point of the article was that they are finding non-human cells in places they didn't believe they existed before. Or more correctly, I believe it was non-human DNA because I think they were using molecular methods to assay samples. I could be wrong though.

But to carry this into the hypothetical, it makes perfect sense to me. We produce specialized cells in our bodies designed to seek out and destroy invaders. But it would be much more efficient if these destroyers were able to distinguish friend from foe because letting allies seek and destroy badguys is much more cost effective than having to manufacture your own soldiers.


----------



## stchupa (Apr 25, 2006)

I think Brent's quite close to hitting the nail on the head.

First of all the body isn't "sterile" (sorry to burst your bubble of granted security), If it were it wouldn't have much use for things such as plateletes, white cells, antibodies and well what ever else left undiscovered/labeled/indexed innate "protection"...then going to the "larger scale" of organs such as kidneys, liver, pancreas. The appendix may be an example to use here. Yes the appendix is technically still part of the exterior, but it is also a potential doorway in. It is analagous to the entrance to a club,as long as the bouncer isn't knocked out, things should remain all 'good'. The body is seperate population of differing organsims that react to eachother in such away as to maintain just enough conflict to set boundries to restrict foreign tissues and the specialied flora taking refuge from infiltrating and upsetting the dynamic balance of the other pop. Many eco-levels to the body, just like a body in space we have trees whos roots only penetrate the non living part of the body (crust/skin), you go deeper (oceans/blood) diversity doesn't deminish only changes and such things as predation become a more primary observation because this balance is unequivical to the deviating swings in climate of the more exterior environment. They have found bacteria that feed on petrol, and rock, again there is no loss the deeper you go only greater specialization taking place. 
Is the core of the Earth "sterile"? You don't have to tel me how stupid that sounds but, who's to say, so far everywhere we can send something of our own to check it out, something has already been there, not to disclude the things below our current level of observation. We know a lot, aboiut virtually nothing. Life is like energy and is indestructable.

It's only inadvertance the the body works as one. If an organism was as efficient to recycle/reuse all of the byproducts that itself produced this cycle wouldn't take place. You can thank "waste" for making you as terribly complicated as you are.  

I think if anyone who has an interest in how existance goes 'round here on Earth and has actively spent time understanding it, won't (or I say shouldn't) be surprized when there's a huge leap in knowledge w/ the shift of interest and perspective.

There have been considerations for DRNA imitation as well by what we consider "our" immune system. I'll go as far to say it is very likely that at least some of our "evolutionary" defenses were somehow obtained and not developed. This isn't only inclusive to knew discoveries but those deemed to be of definite human origin as once thought. What we know as white blood cells being a prime example, but the interesting thing about it is, it does not neccessarily immitate anything human, but somehow still gets its place.

I remember the ratio of human to non-human DNA present out of the average humans mass being 40:60. But I can't be exactly sure if it's more human than not but I'm rather sure it is the latter from what I remeber. But in either case... :shock: It would also depend on the individual. Dio you ever swear we have viruses running this country that somehow maintained a human shell? :roll: 

When/if any of this become puplically substantiated the considerations then pretty much fly out the window. There has been somewhat recent limited research into organ evolution and how the might have differed in design to work w/out sympatric support. Keep in mind something that has been know for a long time is that blood plasma is nearly identical to sea water (as it once was, probably not as is now) in salinity, conductivity and soluble minerals. This compared as a healthy human to a healthy ocean.

I want to fit the gill formation of dart embryos in some how to this, but cant think how. I reminds me of a fan coral but w/ more plant like characteristics. I might sit on that one.


----------

