There are several mechanisms by which bacteria can gain resistance to antibiotics. Antibiotic chemicals usually target specific enzymes in bacteria and disrupt important cellular processes. This kills the bacteria already present or makes it difficult for them to increase their number by reproduction.
Resistance to antibiotics is caused by mutations in bacteria by natural selection. Some mechanisms by which bacteria gain the ability to stay unaffected by antibiotics are:
- Alteration in the proteins that are targeted by the antibiotics. This could include a change in the structure of the site that the antibiotics bind to or its elimination altogether.
- Drugs enter the bacterial cell through a outer membrane protein channel. If this is modified or eliminated, antibiotics are unable to cause any damage to the bacteria as they have no access to components within the bacterial cell.
- Creation of a system that results in the expulsion of the antibiotic from within the bacteria before it can start to cause any damage.
- Enzyme creation that makes the antibiotic chemical inactive and it can no longer perform the function that it was meant to.