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I wonder if you could get a system set up where, once we start using this, we put all the old antibiotics on a shelf. If bacteria never are exposed to them, th
by danielweber 12y ago
I wonder if you could get a system set up where, once we start using this, we put all the old antibiotics on a shelf. If bacteria never are exposed to them, they'll eventually lose their resistance, and so when we pull them out again they'll be almost as good as new.
EDIT further down people are making the same point (I think)
- corndoge 12y agoBacteria, and life in general, typically doesn't un-mutate and lose defensive abilities that allowed the previous generation to survive.
- scott_s 12y agoActually, they do. If selection pressure for a particular phenotype no longer exists, then you may lose those genes through genetic drift. edit: philwelch argues in a comment in this thread that this exact thing happens: https://news.ycombinator.com/item?id=8853769 https://news.ycombinator.com/item?id=8853769
- hga 12y agoActually, bacteria are, shall we say, particularly mutable (only one strand of genomic DNA, plus plasimids if they're useful), and they can do so rapidly. It's an issue of selection pressures. If they live in a competitive environment, which includes competing against each other, then the most "fit" ones win by out reproducing the competition. Mutations that made them more fit in an environment rife with antibiotic X may be mostly harmless in the absence of X, or might consume resources that can ill be afforded. See e.g. this subthread for more discussion: https://news.ycombinator.com/item?id=8853232 https://news.ycombinator.com/item?id=8853232
- gtirloni 12y agoThanks for all your thoughtful / very informative answers. Really appreciated it.
- tuxracer 12y agoThere is a price to be paid for those defensive abilities. If paying that price no longer affords any benefit that would put selective pressure on removing those now needless defenses.