Source: https://senecalearning.com/en-gb/definitions/antibiotics/

# Antibiotics

Antibiotics, such as penicillin, are drugs developed to cure infections caused by bacteria. Some antibiotics work by destroying the cell wall of the bacteria so that they can't replicate.

- **Antibiotics do not affect viruses -** Antibiotics do not destroy viruses because viruses stay inside host cells and are not living cells.
- **Antibiotics are specific -** Specific antibiotics are prescribed by medical doctors for specific diseases. The use of antibiotics has greatly reduced the number of deaths from infectious bacterial diseases.

## Antibiotic Resistance

Some strains of bacteria are resistant to certain antibiotics. This means that these antibiotics cannot kill them. **MRSA** is often called a “superbug” because it is resistant to many antibiotics.

**How to stop antibiotic resistance?**

To help prevent strains of resistant bacteria from developing:

- Doctors should only prescribe antibiotics if they are needed and not for minor infections or viral infections.
- Patients should complete their course of antibiotics to ensure all bacteria are killed.

Bacteria can become resistant to antibiotics. This is the process:

1. Random mutations - Within a population of bacteria, some will have random mutations (random change in DNA). The mutated bacteria are resistant to antibiotics and so they are able to survive, whilst the non-resistant bacteria die.
2. Natural selection - The resistant bacteria can reproduce rapidly because their competition (the non-resistant bacteria) has been destroyed by the antibiotic. When the resistant bacteria reproduce, they produce genetically-identical copies. These copies will all be resistant to the antibiotics.

![Process of Antibiotic Resistance](https://assets-cdn.senecalearning.com/assets/images/e224fd131815dc1ad79528d540bf0c9ae4141436-480x300.png?q=90)

In a population of bacteria, a random mutation can arise, which makes that bacteria more resistant to antibiotics. The resistant bacteria reproduce asexually, so the copies will be genetically identical.