Resistant bacteria — AQA GCSE Biology
Test yourself on Resistant bacteria with AQA GCSE practice questions.
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Resistant bacteria explained
MRSA stands for meticillin-resistant Staphylococcus aureus.
Read the full explanation
It is a strain of the bacterium Staphylococcus aureus that is resistant to several antibiotics, including meticillin and often related antibiotics. This means that infections caused by MRSA are difficult to treat because the usual antibiotics do not kill the bacteria. MRSA can cause serious infections, particularly in hospitals or care settings where people may have wounds, catheters or weakened immune systems. The resistance arises from random mutations and is inherited by offspring, so resistant populations increase when antibiotics are used. Understanding MRSA helps explain why inappropriate antibiotic use is dangerous and why infection control is important.
Your focus
- Identify MRSA as a resistant strain of Staphylococcus aureus.
- Explain why MRSA infections are difficult to treat.
- Relate MRSA to the wider issue of antibiotic resistance in healthcare.
Resistant bacteria exam tips
Marking Points
- MRSA is a strain of Staphylococcus aureus.
- MRSA is resistant to antibiotics, including meticillin and often other antibiotics.
- Infections caused by MRSA are difficult to treat because antibiotics may not work.
- MRSA is a particular concern in healthcare settings such as hospitals.
- Resistance is inherited and can spread through bacterial reproduction.
Examiner Tips
- 💡State that MRSA is a bacterium and a strain of Staphylococcus aureus.
- 💡Mention that it is resistant to antibiotics and therefore hard to treat.
- 💡Link MRSA to hospital infections and infection control.
Common Mistakes
- Thinking MRSA is a virus: it is a bacterium.
- Believing MRSA is resistant to all antibiotics: it is resistant to several, but some antibiotics may still be effective.
- Confusing MRSA with a human immune response: resistance is a property of the bacterium.