3 ms·

If everybody starts using this molecule, isn't the bacterium going to adapt, like with antibiotics?

drostie 14y ago
It is quite possible. Bacteria do all sorts of weird and wonderful things to have high genetic diffusion. One of the most interesting is that bacteria will sometimes link up to other bacteria to upload a copy of their genetic codes. (!) There is a little bit of hope that it could last for a reasonable amount of time, if properly handled. The issue is that organisms can't adapt if the dosage is too high. Usually adapting to a new threat requires, say, a dozen little changes which each improve survival by 5-10%, rather than one monolithic change which improves survival to 100%. Those combinatorics can only work out if most of the bacteria are being destroyed, not if all of them are. Antibiotics are used this way today. Many people cancel an antibiotic regimen when they feel better, and it's a medical disaster when they do: the antibiotics need to be continued to the point of Total Destruction of all bacteria in your body, which will make you feel weaker, simply so that none of them are naturally selected to have one or two of these 5%-resistance genes. The same thing happened with DDT and insects. There was a use of DDT -- spraying inside your house -- which had low environmental impact and which insects could not develop resistance to, because the concentrations stay high. This made it amazing as an antimalarial: mosquitoes just always perch on walls and wait until the night comes before they attack, and we could use this to always give them a lethal dosage. Unfortunately, someone gave DDT to the farmers and then two things happened: (1) DDT got into the food supply for birds, posing serious environmental risks; and (2) insects could now receive a "partial dose" of DDT and develop those sorts of immunities, so now there are DDT-resistant insect populations.
adventureful 14y ago
Worse, people exchange mouth bacteria regularly. Provides the perfect rapid evolution landscape to build super bacteria. So even if perhaps a few % start using it, it might be enough to set off a situation where people that didn't use it get harmed by people that did by acquiring super bacteria that they then have to treat / fight.
Dove 14y ago
That depends entirely on how it works, and how hard it is to adapt to. Quinine was used to combat malaria for two centuries, and it's still pretty effective. It isn't used as much today because of its side effects, but the fact that it held up as effective for so long is impressive. Some of the modern antimalarial drugs have seen better resistance develop much faster. It's at least partly a question of how much the bacteria would have to change itself to adapt. I would expect something really targeted -- that kills only that one type of bacteria and not other things (such as you) -- to be more likely to have an exploitable weakness than something that kills everything (e.g., mouthwash).

It is quite possible. Bacteria do all sorts of weird and wonderful things to have high genetic diffusion. One of the most interesting is that bacteria will sometimes link up to other bacteria to upload a copy of their genetic codes. (!) There is a little bit of hope that it could last for a reasonable amount of time, if properly handled. The issue is that organisms can't adapt if the dosage is too high. Usually adapting to a new threat requires, say, a dozen little changes which each improve survival by 5-10%, rather than one monolithic change which improves survival to 100%. Those combinatorics can only work out if most of the bacteria are being destroyed, not if all of them are. Antibiotics are used this way today. Many people cancel an antibiotic regimen when they feel better, and it's a medical disaster when they do: the antibiotics need to be continued to the point of Total Destruction of all bacteria in your body, which will make you feel weaker, simply so that none of them are naturally selected to have one or two of these 5%-resistance genes. The same thing happened with DDT and insects. There was a use of DDT -- spraying inside your house -- which had low environmental impact and which insects could not develop resistance to, because the concentrations stay high. This made it amazing as an antimalarial: mosquitoes just always perch on walls and wait until the night comes before they attack, and we could use this to always give them a lethal dosage. Unfortunately, someone gave DDT to the farmers and then two things happened: (1) DDT got into the food supply for birds, posing serious environmental risks; and (2) insects could now receive a "partial dose" of DDT and develop those sorts of immunities, so now there are DDT-resistant insect populations.

adventureful 14y ago

Worse, people exchange mouth bacteria regularly. Provides the perfect rapid evolution landscape to build super bacteria. So even if perhaps a few % start using it, it might be enough to set off a situation where people that didn't use it get harmed by people that did by acquiring super bacteria that they then have to treat / fight.

Dove 14y ago

That depends entirely on how it works, and how hard it is to adapt to. Quinine was used to combat malaria for two centuries, and it's still pretty effective. It isn't used as much today because of its side effects, but the fact that it held up as effective for so long is impressive. Some of the modern antimalarial drugs have seen better resistance develop much faster. It's at least partly a question of how much the bacteria would have to change itself to adapt. I would expect something really targeted -- that kills only that one type of bacteria and not other things (such as you) -- to be more likely to have an exploitable weakness than something that kills everything (e.g., mouthwash).