4 ms·

I don't think there's a way of killing microbiota that creates no pressure for resistance, that's just evolution. Of course some adaptations are more likely th

I don't think there's a way of killing microbiota that creates no pressure for resistance, that's just evolution. Of course some adaptations are more likely than others, but from a pedantic point of view "use sparingly" is all we have.

withinboredom 4y ago
I think in this case it destroys the cell walls, so they’d have to completely evolve how cells work in order to evolve. Thus by definition, if they evolved to survive these substances, they’d be an entirely different organism.
- pasquinelli 4y ago
  anything evolving in any way at all makes it a different organism. evolution is the word for organisms changing at the population level.
  - withinboredom 4y ago
    I don’t think you understand. Like it would have to evolve into an entirely different class of life, it would no longer be “bacteria” thus “bacteria” can never become resistant to it because to become resistant means that it is no longer “bacteria”
    - fvold 4y ago
      You can't outgrow your lineage in evolution. We're monkeys. KFC is made of dinosaurs. Anything descended from bacteria would still be bacteria.
      - withinboredom 4y ago
        They would change taxonomy to archea (see MatrixMan’s comment) thus no longer being bacteria. These are all human issues, the “archea-bacteria” wouldn’t care what we called it, but fun to think about.
      - deleted 4y ago
        [deleted]
    - pasquinelli 4y ago
      > Like it would have to evolve into an entirely different class of life what do you know what it would have to do? sure, bleach dissolves bacteria cell walls, so for a change to make bleach coming into contact with cell walls not dissolve them would make the cell walls not belong to a bacterium, but what if the bleach that you apply to a surface to kill bacteria is prevented from making contact with the cell wall of a bacterium through some unforeseeable adaptation of that bacterium? now it's resistant to bleach but still a bacteria, and now it's out-reproducing other bacteria. what adaptation would cause that? no one could say, it's _unforeseeable_. the actual situation of interest isn't bleach coming in contact with bacteria, it's humans trying to disinfect surfaces by applying bleach.
- __MatrixMan__ 4y ago
  > they’d be an entirely different organism. Yeah, they'd be archaea instead of bacteria, which is a huge taxonomic leap, but they'd probably make you just as sick as before. The naming hierarchies of taxonomy are somewhat justified within eukarya because we have family trees, but when you only have one parent and get your genetic diversity via horizontal gene transfer with your peers, taxonomy is just the words of silly humans. I wouldn't be surprised if mutations happen that take populations across that boundary all the time. It happened at least once, what are the odds of it happening only once? ----- New-cell-wall technology aside, I think there are other reasons to avoid frequently creating unnecessary sterile zones. At those zones' boundaries you're creating situations that favor rapid recolonization, neighbors-be-damned, potentially at the expense of equilibria-seeking behavior. Fewer Ghandis more Ghengis Khans. There's a great radio-lab podcast (titled Argentine Invasion) which describes how conditions like these (regarding a floodplain, in this case) lead to the evolution of an especially ruthless species of ant. It seems likely to me that you'd see the same thing in bacteria populations that are frequently partially obliterated.
Robotbeat 4y ago
One approach is just to starve it of resources such as food or water.
- anonymouskimmer 4y ago
  That would promote spore formation in spore-forming bacteria. And spores are more resistant to damage than active bacteria. And spores can stay viable for years.
  - giantg2 4y ago
    Fun fact, if you have spores you can create the conditions for them to become active for 24 hours or so. Then you can use a sanitizing method that's less intense. This is sometimes used in mushroom cultivation.
kube-system 4y ago
Yes, but if it is something extremely devastating, it might take millions of years of consistent use. Maybe e coli can figure out how to live in an autoclave after a million years, but humans will probably stop using autoclaves before then.
- giantg2 4y ago
  Depending on the temperature, prions can survive at the lower ranges. 2.5% bleach solution will denatured them though.
  - kube-system 4y ago
    Prions are not living and do not evolve.
    - giantg2 4y ago
      Well, it seems that you can have new prion diseases emerge. Not technically evolution since it's not reproduction, but still a similar theory where new proteins or folds could create more resilient structures. Even for true evolution you're looking at variations in sequences leading to both better and worse states. The point is, not all autoclaves destroy everything today.
anonymouskimmer 4y ago
For microbes bleach is the equivalent of a cluster bomb. If you know it's coming you can evolve to decrease the odds of it killing you, but if you don't know it's coming there's nothing you can do. One thing some bacteria can do is create spores. These are a main reason various disinfectants, including dilute bleach mixtures, say they kill 99.999% of germs, and not 100%. Spores are highly, though not totally, resistant to damage. They can even survive autoclaving at standard autoclave temperatures and pressures. But making spores is the equivalent of sticking baby Superman in a pod and sending him to Earth. Spores are the next generation, the adult generation still dies. There are apparently better chlorine disinfectants than bleach which show good activity against spores: https://www.cdc.gov/infectioncontrol/guidelines/disinfection/disinfection-methods/chemical.html https://www.cdc.gov/infectioncontrol/guidelines/disinfection... > Alternative compounds that release chlorine and are used in the health-care setting include demand-release chlorine dioxide, sodium dichloroisocyanurate, and chloramine-T. The advantage of these compounds over the hypochlorites is that they retain chlorine longer and so exert a more prolonged bactericidal effect. > In vitro suspension tests showed that solutions containing about 140 ppm chlorine dioxide achieved a reduction factor exceeding 10^6 of S. aureus in 1 minute and of Bacillus atrophaeus spores in 2.5 minutes in the presence of 3 g/L bovine albumin. The potential for damaging equipment requires consideration because long-term use can damage the outer plastic coat of the insertion tube. In another study, chlorine dioxide solutions at either 600 ppm or 30 ppm killed Mycobacterium avium-intracellulare within 60 seconds after contact but contamination by organic material significantly affected the microbicidal properties.
- cratermoon 4y ago
  > One thing some bacteria can do is create spores. Spores and biofilms. Biofilms not only protect against antibiotics but also bleach. Some of them repel water better than Teflon. https://www.pnas.org/doi/10.1073/pnas.1011033108 https://www.pnas.org/doi/10.1073/pnas.1011033108 "The biofilm surface remains nonwetting against up to 80% ethanol as well as other organic solvents and commercial biocides across a large and clinically important concentration range."
nordsieck 4y ago
> I don't think there's a way of killing microbiota that creates no pressure for resistance, that's just evolution. In order for evolution to function[1], there needs to be differential survival. That is to say, some variants of bacteria must survive at greater or lesser rates than other variants. For something as strong as bleach, given sufficient concentration and working time, it's not clear to me that that effect exists. My understanding is that it's so powerful and it's means of action is so robust that is just kills everything equally. --- 1. Yes, technically evolution never stops and always functions. I guess a more precise way to word that is: in order for there to be an observable evolutionary effect.
- deleted 4y ago
  [deleted]
angst_ridden 4y ago
yes, but the difference between having your biological processes disrupted and being smashed with a rock are pretty significant, and the evolutionary responses are quite different.

withinboredom 4y ago

I think in this case it destroys the cell walls, so they’d have to completely evolve how cells work in order to evolve. Thus by definition, if they evolved to survive these substances, they’d be an entirely different organism.

pasquinelli 4y ago
anything evolving in any way at all makes it a different organism. evolution is the word for organisms changing at the population level.
- withinboredom 4y ago
  I don’t think you understand. Like it would have to evolve into an entirely different class of life, it would no longer be “bacteria” thus “bacteria” can never become resistant to it because to become resistant means that it is no longer “bacteria”
  - fvold 4y ago
    You can't outgrow your lineage in evolution. We're monkeys. KFC is made of dinosaurs. Anything descended from bacteria would still be bacteria.
    - withinboredom 4y ago
      They would change taxonomy to archea (see MatrixMan’s comment) thus no longer being bacteria. These are all human issues, the “archea-bacteria” wouldn’t care what we called it, but fun to think about.
    - deleted 4y ago
      [deleted]
  - pasquinelli 4y ago
    > Like it would have to evolve into an entirely different class of life what do you know what it would have to do? sure, bleach dissolves bacteria cell walls, so for a change to make bleach coming into contact with cell walls not dissolve them would make the cell walls not belong to a bacterium, but what if the bleach that you apply to a surface to kill bacteria is prevented from making contact with the cell wall of a bacterium through some unforeseeable adaptation of that bacterium? now it's resistant to bleach but still a bacteria, and now it's out-reproducing other bacteria. what adaptation would cause that? no one could say, it's _unforeseeable_. the actual situation of interest isn't bleach coming in contact with bacteria, it's humans trying to disinfect surfaces by applying bleach.
__MatrixMan__ 4y ago
> they’d be an entirely different organism. Yeah, they'd be archaea instead of bacteria, which is a huge taxonomic leap, but they'd probably make you just as sick as before. The naming hierarchies of taxonomy are somewhat justified within eukarya because we have family trees, but when you only have one parent and get your genetic diversity via horizontal gene transfer with your peers, taxonomy is just the words of silly humans. I wouldn't be surprised if mutations happen that take populations across that boundary all the time. It happened at least once, what are the odds of it happening only once? ----- New-cell-wall technology aside, I think there are other reasons to avoid frequently creating unnecessary sterile zones. At those zones' boundaries you're creating situations that favor rapid recolonization, neighbors-be-damned, potentially at the expense of equilibria-seeking behavior. Fewer Ghandis more Ghengis Khans. There's a great radio-lab podcast (titled Argentine Invasion) which describes how conditions like these (regarding a floodplain, in this case) lead to the evolution of an especially ruthless species of ant. It seems likely to me that you'd see the same thing in bacteria populations that are frequently partially obliterated.

Robotbeat 4y ago

One approach is just to starve it of resources such as food or water.

anonymouskimmer 4y ago
That would promote spore formation in spore-forming bacteria. And spores are more resistant to damage than active bacteria. And spores can stay viable for years.
- giantg2 4y ago
  Fun fact, if you have spores you can create the conditions for them to become active for 24 hours or so. Then you can use a sanitizing method that's less intense. This is sometimes used in mushroom cultivation.

kube-system 4y ago

Yes, but if it is something extremely devastating, it might take millions of years of consistent use. Maybe e coli can figure out how to live in an autoclave after a million years, but humans will probably stop using autoclaves before then.

giantg2 4y ago
Depending on the temperature, prions can survive at the lower ranges. 2.5% bleach solution will denatured them though.
- kube-system 4y ago
  Prions are not living and do not evolve.
  - giantg2 4y ago
    Well, it seems that you can have new prion diseases emerge. Not technically evolution since it's not reproduction, but still a similar theory where new proteins or folds could create more resilient structures. Even for true evolution you're looking at variations in sequences leading to both better and worse states. The point is, not all autoclaves destroy everything today.

anonymouskimmer 4y ago

For microbes bleach is the equivalent of a cluster bomb. If you know it's coming you can evolve to decrease the odds of it killing you, but if you don't know it's coming there's nothing you can do. One thing some bacteria can do is create spores. These are a main reason various disinfectants, including dilute bleach mixtures, say they kill 99.999% of germs, and not 100%. Spores are highly, though not totally, resistant to damage. They can even survive autoclaving at standard autoclave temperatures and pressures. But making spores is the equivalent of sticking baby Superman in a pod and sending him to Earth. Spores are the next generation, the adult generation still dies. There are apparently better chlorine disinfectants than bleach which show good activity against spores: https://www.cdc.gov/infectioncontrol/guidelines/disinfection/disinfection-methods/chemical.html https://www.cdc.gov/infectioncontrol/guidelines/disinfection... > Alternative compounds that release chlorine and are used in the health-care setting include demand-release chlorine dioxide, sodium dichloroisocyanurate, and chloramine-T. The advantage of these compounds over the hypochlorites is that they retain chlorine longer and so exert a more prolonged bactericidal effect. > In vitro suspension tests showed that solutions containing about 140 ppm chlorine dioxide achieved a reduction factor exceeding 10^6 of S. aureus in 1 minute and of Bacillus atrophaeus spores in 2.5 minutes in the presence of 3 g/L bovine albumin. The potential for damaging equipment requires consideration because long-term use can damage the outer plastic coat of the insertion tube. In another study, chlorine dioxide solutions at either 600 ppm or 30 ppm killed Mycobacterium avium-intracellulare within 60 seconds after contact but contamination by organic material significantly affected the microbicidal properties.

cratermoon 4y ago
> One thing some bacteria can do is create spores. Spores and biofilms. Biofilms not only protect against antibiotics but also bleach. Some of them repel water better than Teflon. https://www.pnas.org/doi/10.1073/pnas.1011033108 https://www.pnas.org/doi/10.1073/pnas.1011033108 "The biofilm surface remains nonwetting against up to 80% ethanol as well as other organic solvents and commercial biocides across a large and clinically important concentration range."

nordsieck 4y ago

> I don't think there's a way of killing microbiota that creates no pressure for resistance, that's just evolution. In order for evolution to function[1], there needs to be differential survival. That is to say, some variants of bacteria must survive at greater or lesser rates than other variants. For something as strong as bleach, given sufficient concentration and working time, it's not clear to me that that effect exists. My understanding is that it's so powerful and it's means of action is so robust that is just kills everything equally. --- 1. Yes, technically evolution never stops and always functions. I guess a more precise way to word that is: in order for there to be an observable evolutionary effect.

deleted 4y ago
[deleted]

angst_ridden 4y ago

yes, but the difference between having your biological processes disrupted and being smashed with a rock are pretty significant, and the evolutionary responses are quite different.