The problem with killing bacteria isn't that we are lacking ways to do so. Steeping them in a strong acid should make sure they are killed and they should not find a way to develop resistance to a strong acid.
The problem is we want to kill them, while in human body, without causing too much detriment to the host.
To do this, we essentially need to develop something that will cause serious harm to the bacteria and yet not harm human cells. This means exploiting various differences between bacteria and humans.
A polymer that kills cell walls indiscriminately is hardly an acceptable solution for a human. Yes, bacteria may not be able to gain resistance to it but also it can't ever be used on a real human because mass cell death will cause too much damage to the human.
And "solving the problem of selectivity" will cause bacteria to be able to find their resistance eventually. Because if it is possible to escape your cell wall getting disrupted because you have specific DNA -- a bacteria can gain resistance.
I am firmly of the opinion it is not possible to develop an antibiotic guaranteeing the bacteria will not be able to gain resistance to it.
Simply -- the resistance can be had as evidenced by human cells. And the genetic material is abundantly available to the bacteria -- they are pretty much surrounded by it while in our bodies. There is always going to be non-zero chance for resistance to be acquired by a cell and then spread to the offspring.
The thing is, we need to kill bacterias in many other places than the human body:
- medical equipment: handles for scalpels, syringes, operation tables... All those things we need to clean again and again.
- passage ways: doors, handles, stairs handrails, subway grab bars... All the things that propagate infections in very dense populated areas.
- research fabs: hazmat suits, protection googles, fum hood protections,... All the stuff you want to make sure don't end up cross contaminate your batch or escape.
> I am firmly of the opinion it is not possible to develop an antibiotic guaranteeing the bacteria will not be able to gain resistance to it.
I think the main approach to prevent antibiotic resistance is coming up with a way to prevent bacteria ever coming across a low dose of the antibiotic. As long as we make sure the dose is either huge or zero, antibiotic resistance shouldn't evolve.
Unfortunately, humans aren't a well controlled lab experiment - and there will always be people taking a half-dose, or flushing the antibiotics down the drain where they get diluted and suddenly trillions of sewer bacteria get exposed to a low dose and suddenly start developing resistance.
I am as layperson as they get on this subject matter, but I would think that even if your statement is true, perhaps we can get to the point where bacteria need to evolve so much to overcome new antibiotic approaches that they lose some of the properties that make them harmful and transmissible, i.e. it becomes harder for them to exist outside of the host, penetrate the host's defenses, etc. At some point a bacteria would need to seem so like a human cell or beneficial bacteria that it becomes non-harmful.
> A polymer that kills cell walls indiscriminately is hardly an acceptable solution for a human.
On the contrary. Animal cells do not have cell walls. They have cell membranes but that's a different thing. Many existing antibiotics interfere with the cell walls of bacteria.
> To do this, we essentially need to develop something that will cause serious harm to the bacteria and yet not harm human cells.
The other problem is we depend on mutualistic bacteria to survive, if we kill all bacteria in our bodies we’ll die of malnutrition. And even worse sometimes the problem is those mutualistic bacteria getting out of balance, so we need to kill some while promoting an increase of others.
And those bacteria are constantly topped up from the environment, so we can live in a sterile environment our whole lives. It’s a delicate balance, we can’t just throw anti-bacterial things around without thought.
This is really cool and humans are amazing. You have to be relentlessly resourceful to engineer a material and study it like they’ve done.
If you read the paper, however, you see that it’s more about chemists showing off a tour de force. The application itself is not exactly novel. It’s a solution looking for a problem. https://www.pnas.org/doi/10.1073/pnas.2311396120
Which takes nothing away from their remarkable effort. Kudos!
Isn't that a way of saying "no bacteria can ever adapt to this method of killing them"? Won't at least 0.1% of them find a way to survive, and gradually adapt to this as well?
I dont see why that would be true. The liklihood of adaption depends on the details of the method. Not everything is easily adapted out of.
Humans have been shooting each other with guns, and before that bows and arrows for a long time, and yet evolution hasn't provided us with fire-arm resitance yet.
"bacteria do not seem to develop resistance" - Dr. Quentin Michaudel
The press release is (predictably) more cavalier in its claim!
All this release says is that the polymers "[disrupt] the membrane of these microorganisms". At that level of detail, penicillin works similarly, and is vulnerable to resistance.
I'd love to know more detail about how this is a different kind of disruption.
I thought there was a sort of "iron triangle" between antibiotics and phage therapy where bacteria couldn't maintain resistance to both. But OTOH phage therapy is several decades old and still rarely used
Unless it's 100% effective, how could it not induce antibiotic resistance? And anything that's 100% effective is likely going to do damage to something else, no?
It's a mechanical method of action rather that chemical (think targeted receptors/activation sites). An oversimplication would be to liken it to barbed wire.
As for you next question, they call out the need to investigate making it selective for bacteria vs human cells. So it seems it has no selectivity at present and will kill other things. And, as I understand it, changing it from being 100% effective to being selective will introduce evolutionary pressure for resistence bateria strains.
So this might be neat for materials and creating a sterile environment rather than chasing in vivo applications.
Antibiotics produce chemical effects in the bacteria; eg disrupting metabolic processes. We like antibiotics because they target bacteria without injuring the host. Antibiotics are subject to antibiotic resistance because some bacteria are resistant to the chemical mechanism used.
There are antibacterial substances that don’t target metabolic processes. They function in various ways- soap binds to the bacteria and to water and allows them to be washed away. Lysol uses a heavily basic solution to chemically damage the bacteria. These are not 100% effective because nobody uses them long enough or in enough concentration to be 100% effective, because they also affect the host. I guess it’s conceivable that a bacterium could evolve a non-lipid cell membrane or resistance to high pH, but these would be much more massive mutations than slight changes in metabolism.
From the article: “The new polymers we synthesized could help fight antibiotic resistance in the future by providing antibacterial molecules that operate through a mechanism against which bacteria do not seem to develop resistance.”
The word “seem” is doing a lot of work there. I guess we’ll have to wait and see what the long term / extensive tests show.
I wonder if this will provide any way to deal with resistant tuberculosis. One of the treatments for MDR TB is removing the infected portion of the lung. https://pubmed.ncbi.nlm.nih.gov/26757804/
I have been colonized with "mostly" dormant MRSA for a couple years now. The idea of ever needing surgery terrifies me because I know I could die from a flareup in the "weakened" part of my body.
I tried fighting it in the past but the stomach damage from long treatment regiments just wasn't worth it, not to mention the risk of getting reinfected from my home. I hope a non-harmful and reliable cure is available someday.
In 30 years we will be seeing class action lawsuits and regulatory action about bacteria-inhibiting polymers contaminating food supply and particles in the oceans.
No one will look back and estimate the number of lives saved; they and their lawyers will simply bankrupt the company that productizes this technology.
[+] [-] onetimeuse92304|2 years ago|reply
The problem is we want to kill them, while in human body, without causing too much detriment to the host.
To do this, we essentially need to develop something that will cause serious harm to the bacteria and yet not harm human cells. This means exploiting various differences between bacteria and humans.
A polymer that kills cell walls indiscriminately is hardly an acceptable solution for a human. Yes, bacteria may not be able to gain resistance to it but also it can't ever be used on a real human because mass cell death will cause too much damage to the human.
And "solving the problem of selectivity" will cause bacteria to be able to find their resistance eventually. Because if it is possible to escape your cell wall getting disrupted because you have specific DNA -- a bacteria can gain resistance.
I am firmly of the opinion it is not possible to develop an antibiotic guaranteeing the bacteria will not be able to gain resistance to it.
Simply -- the resistance can be had as evidenced by human cells. And the genetic material is abundantly available to the bacteria -- they are pretty much surrounded by it while in our bodies. There is always going to be non-zero chance for resistance to be acquired by a cell and then spread to the offspring.
[+] [-] BiteCode_dev|2 years ago|reply
- medical equipment: handles for scalpels, syringes, operation tables... All those things we need to clean again and again.
- passage ways: doors, handles, stairs handrails, subway grab bars... All the things that propagate infections in very dense populated areas.
- research fabs: hazmat suits, protection googles, fum hood protections,... All the stuff you want to make sure don't end up cross contaminate your batch or escape.
So it's still very useful.
[+] [-] londons_explore|2 years ago|reply
I think the main approach to prevent antibiotic resistance is coming up with a way to prevent bacteria ever coming across a low dose of the antibiotic. As long as we make sure the dose is either huge or zero, antibiotic resistance shouldn't evolve.
Unfortunately, humans aren't a well controlled lab experiment - and there will always be people taking a half-dose, or flushing the antibiotics down the drain where they get diluted and suddenly trillions of sewer bacteria get exposed to a low dose and suddenly start developing resistance.
[+] [-] lemmsjid|2 years ago|reply
[+] [-] vmarovic|2 years ago|reply
Human cells don’t have cell walls, so it would not affect them.
[+] [-] Turing_Machine|2 years ago|reply
On the contrary. Animal cells do not have cell walls. They have cell membranes but that's a different thing. Many existing antibiotics interfere with the cell walls of bacteria.
[+] [-] sitharus|2 years ago|reply
The other problem is we depend on mutualistic bacteria to survive, if we kill all bacteria in our bodies we’ll die of malnutrition. And even worse sometimes the problem is those mutualistic bacteria getting out of balance, so we need to kill some while promoting an increase of others.
And those bacteria are constantly topped up from the environment, so we can live in a sterile environment our whole lives. It’s a delicate balance, we can’t just throw anti-bacterial things around without thought.
[+] [-] apienx|2 years ago|reply
If you read the paper, however, you see that it’s more about chemists showing off a tour de force. The application itself is not exactly novel. It’s a solution looking for a problem. https://www.pnas.org/doi/10.1073/pnas.2311396120
Which takes nothing away from their remarkable effort. Kudos!
[+] [-] gentleman11|2 years ago|reply
Isn't that a way of saying "no bacteria can ever adapt to this method of killing them"? Won't at least 0.1% of them find a way to survive, and gradually adapt to this as well?
[+] [-] bawolff|2 years ago|reply
Humans have been shooting each other with guns, and before that bows and arrows for a long time, and yet evolution hasn't provided us with fire-arm resitance yet.
[+] [-] kulahan|2 years ago|reply
It sounds like it would be equivalent to humans evolving bulletproof skin. (quote is from their original paper which is linked in the article)
[+] [-] xaellison|2 years ago|reply
The press release is (predictably) more cavalier in its claim!
All this release says is that the polymers "[disrupt] the membrane of these microorganisms". At that level of detail, penicillin works similarly, and is vulnerable to resistance.
I'd love to know more detail about how this is a different kind of disruption.
[+] [-] lainga|2 years ago|reply
[+] [-] xxpor|2 years ago|reply
[+] [-] DistractionRect|2 years ago|reply
As for you next question, they call out the need to investigate making it selective for bacteria vs human cells. So it seems it has no selectivity at present and will kill other things. And, as I understand it, changing it from being 100% effective to being selective will introduce evolutionary pressure for resistence bateria strains.
So this might be neat for materials and creating a sterile environment rather than chasing in vivo applications.
Edit: autocorrect wronged a word
[+] [-] efitz|2 years ago|reply
There are antibacterial substances that don’t target metabolic processes. They function in various ways- soap binds to the bacteria and to water and allows them to be washed away. Lysol uses a heavily basic solution to chemically damage the bacteria. These are not 100% effective because nobody uses them long enough or in enough concentration to be 100% effective, because they also affect the host. I guess it’s conceivable that a bacterium could evolve a non-lipid cell membrane or resistance to high pH, but these would be much more massive mutations than slight changes in metabolism.
[+] [-] burlesona|2 years ago|reply
The word “seem” is doing a lot of work there. I guess we’ll have to wait and see what the long term / extensive tests show.
[+] [-] unknown|2 years ago|reply
[deleted]
[+] [-] echelon|2 years ago|reply
Obviously not the best for human application, but it'll work in the lab.
[+] [-] epgui|2 years ago|reply
[+] [-] ssnistfajen|2 years ago|reply
[+] [-] HankB99|2 years ago|reply
[+] [-] offtrail|2 years ago|reply
[+] [-] unknown|2 years ago|reply
[deleted]
[+] [-] zaik|2 years ago|reply
[+] [-] jjkeddo199|2 years ago|reply
I tried fighting it in the past but the stomach damage from long treatment regiments just wasn't worth it, not to mention the risk of getting reinfected from my home. I hope a non-harmful and reliable cure is available someday.
[+] [-] qvrjuec|2 years ago|reply
[+] [-] epgui|2 years ago|reply
[+] [-] JoshTko|2 years ago|reply
[+] [-] echelon|2 years ago|reply
Is there no way to purge it? (Isopropyl bath?)
[+] [-] orangepurple|2 years ago|reply
[+] [-] smegsicle|2 years ago|reply
[+] [-] efitz|2 years ago|reply
No one will look back and estimate the number of lives saved; they and their lawyers will simply bankrupt the company that productizes this technology.
[+] [-] hinkley|2 years ago|reply
[+] [-] unknown|2 years ago|reply
[deleted]
[+] [-] jcoc611|2 years ago|reply