Why might antibiotics become less effective to bacteria over generations?
1 Answer
Due to antibiotic resistance in bacteria.
Explanation:
Antibiotic resistance in bacteria may be caused by a natural mutation in a gene that nullifies the effects of the antibiotic. In a human if antibiotics are consumed all the bacteria without the mutation would die, leaving the antibiotic resistant bacteria to repopulate. Thus the successive generations of bacteria within that person would all have the gene for antibiotic resistance. The process at work here is natural selection where favourable characteristics are selected for within a population.
So more the use of antibiotic, faster the resistance evolves.
Though antibiotic resistance in normal gut bacteria does not pose much of problem by itself, the problem arises if the antibiotic resistant bacteria transfers the antibiotic resistant gene to a pathogen within the person through a plasmid.
So there are two precautions to be taken by doctors:
1. must check the nature of infection (i.e. whether bacterial infection is there or not) before prescribing an antibiotic.
2. when antibiotic is prescribed, explain the importance of completing the course even when symptoms are gone.
read more if you wish
https://socratic.org/biology/evolution/evolution-of-resistant-bacteria
