# 1  To:: Op

Re :: Drug resistant strains . . is a common example . .

Evolution of resistance–bacteria win again
By Tara Smith on November 15th

Drug resistance in strains of antibiotics is evolution in action. The resistance to antibiotics has been a concern of scientists almost since their widespread use began. In a 1945 interview with the New York Times, Alexander Fleming himself warned that the misuse of penicillin could lead to selection of resistant forms of bacteria, and indeed, he’d already derived such strains in the lab by varying doses of penicillin the bacteria were subjected to. A short 5 years later, several hospitals had reported that a majority of their Staph isolates were, as predicted, resistant to penicillin. This decline in effectiveness has led to a search for new sources and kinds of antimicrobial agents. One strategy involves going back to a decades-old approach researched by Soviet scientists: phage therapy. Here, they pit one microbe directly against another, using viruses called bacteriophage to infect, and kill, pathogenic bacteria. Vincent Fischetti at Rockefeller University has used this successfully to kill anthrax, Streptococcus pyogenes, and others. Another novel source of antibiotics has come from our own innate immune system, one of our initial defenses against microbial invaders.

An enormous variety of organisms produce compounds called cationic antimicrobial peptides. A component of our own innate immune system, these are fairly short strings of amino acids (less than 100 a.a.’s) that have a net positive charge. It is thought that these peptides work primarily by disrupting the integrity of the bacterial cell wall, essentially poking holes in the wall, causing death of the cell. Since the peptides are targeted at the bacterial cell wall structure, it was thought that resistance would require a fundamental change in membrane structure, making it an exceedingly rare event. Therefore, these antimicrobial peptides might make an excellent weapon in the fight against multiply drug-resistant bacteria. Additionally, the remarkable diversity of these peptides, combined with the presence of multiple types of peptides with different mechanisms of action present at the infection site, rendered unlikely the evolution of resistance to these molecules (or so the common thinking went). However, evolutionary biologists have pointed out that therapeutic use of these peptides would differ from natural exposure: concentration would be significantly higher, and a larger number of microbes would be exposed. Additionally, resistance to these peptides has been detailed in a few instances. For example, resistance to antimicrobial peptides has been shown to be essential for virulence in Staphylococcus aureus and Salmonella species, but we didn’t *witness* that resistance develop–therefore, it might simply be that those species have physiological properties that render them naturally resistant to many of these peptides, and were never susceptible in the first place.

Antimicrobial resistance is always a problem—it can render antibiotics much less useful, and make deadly infections almost untreatable. But resistance to these peptides could make us all vulnerable. The peptides of our innate immune system are one of our first lines of defense against an immense variety of pathogens, and we don’t know what the outcome may be if we compromise this essential level of protection. But realistically, could such resistance evolve within the bacterial population?

Dr. Michael Zasloff of Georgetown University was originally a doubter. In this 2002 Nature article, he states in conclusion:

    Studies both in the laboratory and in the clinic confirm that emergence of resistance against antimicrobial peptides is less probable than observed for conventional antibiotics, and provides the impetus to develop antimicrobial peptides, both natural and laboratory conceived, into therapeutically useful agents.

Certainly in the short term, resistance was unlikely to evolve for the reasons I mentioned above. However, if these peptides are used over an extended period of time, could the mutations necessary to confer resistance accumulate? This was the question asked in a new study by Dr. Zasloff along with colleagues Gabriel Perron and Graham Bell. Following publication of his 2002 paper where he called evolution of resistance to these peptides “improbable,” Bell challenged Zasloff to test this theory. Zasloff took him up on the offer, and they’ve published their results in Proceedings of the Royal Society.

They tested this using strains of E. coli and Pseudomonas fluorescens. They started out growing these bacteria with low concentrations of a peptide antibiotic called pexiganan, a derivative of a peptide originally isolated from a frog. (Carl Zimmer has an excellent post on this same topic here). The experimental design was quite simple. They grew the bacteria, took a portion of the growth, and added that to a new tube with fresh media. Gradually, they increased the concentration of pexiganan in the growth medium. In all, they did 100 serial transfers of the bacteria (correlating to ~500-600 generations of bacteria), and the end result were–voilà !–bacterial populations that were resistant to the peptides.

Creationists/ID advocates (such as chemist Phil Skell) often claim that “evolutionary theory contributes little to experimental biology,” or that “evolution has little to do with almost all research in biology and biotechnology”, etc. etc. And sure, the theory of evolution didn’t *directly* result in the discovery of peptide antibiotics. But advances in biotechnology do not exist in a vacuum, and we have seen what can occur from the misapplication of these types of technologies, unguided by an understanding of underlying evolutionary principles. Peptide antibiotics have not yet been used clinically to treat human infections, but imagine if they had gone into widespread use without a thought given to the evolution of resistance to these peptides. Imagine if they had gone into widespread use prior to an investigation of the relatedness of various peptides to those produced by humans. Imagine if, as a result of not considering these implications, we had lost an ancient protection against bacteria—-which *evolved* over millions of years of host-pathogen interaction–due to a mere advancement in biotechnology. While I enjoy proving the evolution-doubters wrong, I hope it never comes down to that kind of situation in order to do so, and I hope this example is instructive to those who claim that evolution isn’t useful, and can be used to our advantage.
 

http://answersingenesis.org

http://www.icr.org

 First off, I would just like to say that I very much appreciate how respectful your argument is. In your argument, you have presented logical facts that are worth acknowledging and you were very specific and thorough. That is how all of these arguments should be.

As it would take me far too much time to go through and examine each and every argument you made (you gave a lot), I would like to direct you to this link:

http://www.answersingenesis.org

This website has mountains of information that I'm sure you will find useful, so please visit it.

..higher

re ::  Within the .. time-frame .. do tell me when the O2 levels were 40% higher than today's levels in the earth's atmosphere ?

 Allow me to say hi and a big welcome to you jdude15

   Oh, Within the last 6,000 yr time-frame .. do tell me when the Oxygen levels were 40% higher than than are today ? Provide a time and some data will you ?

: 

p.s.  --   All in good time , I will be waiting so no rush.

  Please allow me to re-state my personal welcome and fond hello to you. I should warn you this is an Atheist site so you can be expected to be challenged. If you are experiencing troubles already, please leave.  It is very REALLY sad, many were wishing they wouldnt lose another opportunity to talk with a YEC. I think you'd make a fine addition to the board. 

A claim the late Morris and Ham make today is there are no transitional and intermediate fossils.

 p.s. -- If someone claims a non-truth to be true; natural the assumption is tending toward a lie (e.g. -- age of the earth, levels of oxygen in the last 6000 yrs, no intermediate/transitional forms found in the fossil record, and so forth).

I'll leave all the fun replies for the others to discuss this silly subject with you, but if you can't see the simplest examples of evolution happening in your every day life you aren't actually looking for the answers or you are ignorant.

 I would first like to admit that using the word "hateful" was rather strong and out of place. I felt a little insulted at the time and I apologize if I made anyone else feel the same way. And you're right, I didn't attempt to refute the specific "facts" that were presented to me, but I also gave JC a link to an entire website with information that would have refuted those "facts" thoroughly and scientifically. It just so happens that nylonase is specifically refuted by an Answers in Genesis scientist on her blog. When you visit the AiG website, just type in the word "nylonase" in the search bar.

But if you want me to give some evidence, then how about the recent "junk DNA" discoveries? Or how about the fact that the entire history of evolution is strikingly devoid of any undisputed transitional fossil forms? Some evolutionists claim that evolution just goes too slowly for us to see it happening today, but even then, we should still be able to detect it in some way. And if the Big Bang is true, where did the first matter come from? Furthermore, mutations result in a loss of genetic information, not a gain.

               first off  'answers in genises' is a religious site  Not a site for science; no matter how often they claim "science"  they ain't.   If you want to see evolution in action,  go look in a mirror then look at your parants & grandparants; you should see simlaritys but you are NOT identicle to daddy;  without evolution you would look identicle to dad, granddad great granddad, me, Adam and every other male on the face of the earth.     Now look at your hands, notice the index finger is much shorter then  your RING finger;  this is true of all men, now look at any females hand their  index fingers and ring fingers are the same length;  why is this? 200,000 years of evolution where males and females have done different work with their hands. Human children are today born with this little quirk, thats evolution.  

                What do I think of creationists?     Watch the video,  that is me in the grey suit, the guy in the bulliet proof hair do has a big pile of notes gleaned from 'answersingenises' .  From my experience in debates the person with the bigger pile of notes doesn't know has much of the topic as he thinks. I had 2 pages of note and I only read from them once.

                         http://www.youtube.com/watch?v=OFLmcDSlrqc  

 Jdude15,

Please accept my apologies, your account was recently deleted in error.  Please feel free to sign back up as jdude15 or if for some reason that doesn't work please choose jdude16 so we can activate your account quickly.  I would have emailed you but it was deleted with your account.  Again I'm sorry, it was the product of attempting to delete spam and your account was deleted by accident.

In Rationality,

I thought you said you were educated about evolution? If you were, you'd know that we're ALL potentially transitional fossils.

I would like to challenge you. If you are educated about evolution, then please write a short paragraph on how it works (You don't have to believe it, just write it as if you were an educated atheist).. Please no copy pasting from others.

I'm pretty sure you will struggle with this, as if you could submit something without it being ripped to shreds here, you wouldn't be asking about 'transitions', 'not happening now', or any other such nonsense.

Do you take the challenge?