Free Antibiotics and Their Use OCR A Level Biology revision notes – covering specification point 4.1.1(n).
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Antibiotics: Importance and Use
Antibiotics are medicines that either kill bacteria or inhibit their growth.
Penicillin, the first antibiotic, was discovered by Alexander Fleming in 1928 from the fungus Penicillium notatum.
Antibiotic Resistance
Antibiotic resistance occurs when bacteria evolve mechanisms to survive exposure to antibiotics. This poses a serious risk to public health, as it can make infections:
- Harder to treat
- More likely to spread
- More likely to cause complications or death
MRSA (methicillin-resistant Staphylococcus aureus) is a major example of a resistant “superbug” that has become prevalent in hospitals, making routine surgery more dangerous.
The factors which accelerate the evolution of antibiotic resistance include:
| Factor | Explanation |
|---|---|
| Overuse of antibiotics | Increases selection pressure for resistance |
| Incomplete courses of treatment | Leaves behind resistant bacteria |
| Use in agriculture | Antibiotics given to livestock may spread resistance genes to human pathogens |