L6 – Controlling Infection

Learning ObjectiveTo be able to decribe how we control infection

Key words: Medicine, mutation, antibiotic resistance, natural selection, MRSA, epidemic, pandemic

Starter activity: Why are you recommended to use the alcohol rub when entering hospitals?

B1 L1

To kill bacteria on hands

Good

Better

Best

Success Criteria

At the end of this lesson it will be:

Able to state how superbugs (highly antibiotic resistant bacteria) develop.

Able to analyse and explain the trends of deaths from MRSA.

Able to state what a epidemic and pandemic is?

Last lesson – How we kill Bacteria

• Antibiotics – These medicines kill bacteria, there are many types used to treat people.

– Penicillin was the first antibiotic discovered and works by breaking down the cell wall of the bacteria causing them to burst.

• However due to our overuse of antibiotics we now have bacteria which are resistant to penicillin!

Last lesson – How we kill Bacteria

• Antibiotics – These medicines kill bacteria, there are many types used to treat people.

– Penicillin was the first antibiotic discovered and works by breaking down the cell wall of the bacteria causing them to burst.

• However due to our overuse of antibiotics we now have bacteria which are resistant to penicillin!

MRSA is one of these Superbugs

How do we get superbugs?

• Bacteria grow and divide every 20 minutes.• Sometime the bacterium produced is not

identical but slightly different to the others due to a change in its DNA.

• This is called a mutation.

Examples of human mutation

• A change in the DNA causes a mutation, it can be anything, sometimes it causes the organism to have an advantage.

This mutation can be anything:

Sometimes the mutation makes the bacteria resistant to the antibiotics, so that they are no longer killed by antibiotics.

How does this mutation mean it wont be destroyed?

The resistant bacteria survive and reproduce and continued use of the antibiotic will only cause the number of resistant bacteria to increase.This is an example of natural selection

Learning objective check

GoodAble to state how superbugs (highly antibiotic resistant bacteria) develop.

Why should you always complete a course of antibiotics?

• If you don’t complete the course it is likely some bacteria will survive and you will become ill again and need a second treatment of a stronger antibiotic

Scientists are continually developing new antibiotics to replace those no longer effective

THINK PAIR AND SHARE

MRSA

• MRSA (Methicillin-resistant Staphylococcus aureus) is a variety that is resistant to many types of antibiotics.

• It is responsible for hundreds of deaths in hospitals

Patients who die with MRSA are usually patients who are already very ill and have a weak immune system (babies)

However when these patients die, the death certificate is not given as the cause of death even though it is.

Science skills activity

Learning objective check

Best Able to analyse and explain the trends of deaths from MRSA.

Prevention

• To prevent more superbugs developing, what should we do?

Write 2 things we could do to prevent more superbugs?

1.To only prescribe an antibiotic to treat serious infection.

2.Clean hospitals with disinfectant.

Flu

• Flu is a virus• It can cause serious illness• Because Flu viruses are always mutating,

producing new strains they are very dangerous, why?

The new strains will be so different people will not be immune to it!This means the new strain will cause more serious injury and spread quickly!

Epidemics

When a flu affects thousand of people in a country it is called a flu epidemic.

Epidemics

When a flu affects thousand of people in a country it is called a flu epidemic.

Pandemic

• When flu spreads rapidly around the world, like SWINE FLU, affects people in many countries.

• This is called PANDEMIC FLU.

To combat this threat the UK government organised vaccination for all vulnerable people and stockpiled Tamiflu and Antiviral drug.

Learning objective check

• Can you define what a pandemic is?• Can you define what an epidemic is?

HOMEWORK

• VACCINATIONS• Write one side of A4 about the advantages

and disadvantages of vaccination.

• In your work you should include the key words• MMR, side effects, autism• And explain how they are related to the

vaccination debate

Exam questions

Why is overuse of antibiotics a problem?

How can we reduce this problem?

Explain how antibiotic resistance develops in bacteria.

What is a mutation?

Why is a mutation in pathogens problematic?

What is an epidemic,?

What is a pandemic, give one example?

What 3 diseases does MMR vaccine protect from?

How can the following drugs be used to treat disease?Painkillers

Antibiotics

Explain how vaccination works:

Explain how white blood cells protect you from disease.

Why can’t antibiotics be used to kill viruses?

Why is overuse of antibiotics a problem?

How can we reduce this problem?

How do bacteria and viruses make you ill?

Explain how antibiotic resistance develops in bacteria.

What is a mutation?

Why is mutatioin in pathogens problematic?

What is a sterile culture. .

Give 2 reasons it is important to keep cultures sterile. .

How do Bacteria multiply in the body?

How do viruses multiply when in the body?

What temperature should we incubate cultures at in school and why? How does this compare to industry?.