MRSA Learning Objectives: To explain how antibiotic resistance can occur. To discuss the possible ways to reduce the spread of MRSA

Starter Describe, with the aid of diagrams, the structure of the Human Immunodeficiency Virus (HIV);

Superbugs! Write down what this phrase means to you.

Antibiotics Antibiotics are widely used as treatment for bacterial infections. Almost as soon as antibiotics started being used, resistant bacteria were found. What should happen is when antibiotics are used, bacteria are killed. This is the case for the majority of the bacteria. However, in the same way we have variation in the human population, there is variation between bacterial populations.

Resistance The bacteria with the resistant gene will survive and go on to multiply. TIP – always use the word ‘resistant’ and never ‘immune’. Bacteria do not have an immune system. Sometimes mutations occur and cause resistance to an antibiotic. They will then multiply and produce resistant offspring.

MRSA There are some bacteria which have evolved to be resistant to most commonly used antibiotics. This is partly due to the fact that antibiotics are over used and used incorrectly. The most well known e.g of this is MRSA (Methicillin Resistant Staphylococcus aureus) S.aureus is a bacterium which often lives harmlessly on the skin and in the nose of many people. It is only if the bacteria gets under the skin that it can cause problems e.f. boils and pneumonia. MRSA is a strain of S.aureus that is resistant to commonly used antibiotics.

MRSA If a normal, healthy person has MRSA then they will rarely show any symptoms or be ill in any way. It is only when the bacteria is passed on to people in hospital, or someone who is already ill, that serious problems occur. As soon as someone in hospital is found to have MRSA then steps must be taken to stop the spread.

TASK Research MRSA in detail and write about the following: How it evolved How it is spread How the spread can be reduced What can be done to reduce the chances of antibiotic resistant bacteria developing. Find out about XDR-TB and MDR-TB