Bacteria have systems such as CRISPR that are specialized in detecting exogenous DNA such as from a potential viral infection.
They also have plasmids that are relatively self-contained genetic packets, which are commonly the site of mutations conferring resistance, and which are often exchanged in the bacterial equivalent of sex.
However, to the best of my knowledge, there’s no specific mechanism for picking out resistance genes from others, beyond simple evolutionary pressures.
The genome is so small and compact that any gene that isn’t ‘pulling its weight’ so to speak will likely be eradicated as it no longer confers a survival advantage, such as when the bacteria find themselves in an environment without antibiotics.
Not to mention that some genes are costly beyond the energy requirements of simply adding more codons, some mechanisms of resistance cause bacteria to build more efflux pumps to chuck out antibiotics, or to use alternate versions of important proteins that aren’t affected by them. Those variants might be strictly worse than the normal susceptible version when antibiotics are absent, and efflux pumps are quite energy intensive.
There’s no real foresight involved, if something isn’t being actively used for a fitness advantage, it’ll end up mercilessly jettisoned .
Bacteria have systems such as CRISPR that are specialized in detecting exogenous DNA such as from a potential viral infection.
They also have plasmids that are relatively self-contained genetic packets, which are commonly the site of mutations conferring resistance, and which are often exchanged in the bacterial equivalent of sex.
However, to the best of my knowledge, there’s no specific mechanism for picking out resistance genes from others, beyond simple evolutionary pressures.
The genome is so small and compact that any gene that isn’t ‘pulling its weight’ so to speak will likely be eradicated as it no longer confers a survival advantage, such as when the bacteria find themselves in an environment without antibiotics.
Not to mention that some genes are costly beyond the energy requirements of simply adding more codons, some mechanisms of resistance cause bacteria to build more efflux pumps to chuck out antibiotics, or to use alternate versions of important proteins that aren’t affected by them. Those variants might be strictly worse than the normal susceptible version when antibiotics are absent, and efflux pumps are quite energy intensive.
There’s no real foresight involved, if something isn’t being actively used for a fitness advantage, it’ll end up mercilessly jettisoned .