its relative, many africans have a mutation that maks then immune to malarial replication yet increases the sickling of erythrocytes. So it a relative thing, in america this is not beneficial, but being immune to an epidemic while risking slight anemia is certainly beneficial.
there are many papers on beneficial mutations, look at antibiotic resistant bacteria, they mutate to increase antibiotic resistant pumps all the time, certainly beneficial.
Are you referign to so called "super bugs"?
* ‘Supergerms’ are actually not ‘super’ at all. They are generally less hardy, and less fit to survive outside of the special conditions in hospitals.
*There are many instances in which germs become resistant by simple selection of resistance which already existed (including that ‘imported’ from other bacteria).
* Where a mutational defect causes resistance, the survival advantage is almost always caused by a loss of information. In no case is there any evidence of an information-adding, ‘uphill’ change.
* ‘Supergerms’ give no evidence to sustain the claim that living things evolved from simple to complex, by adding information progressively over millions of years.
hmmz it appears to be that their mutations are not beneficial
