Hi there.

I'm Mrs. Kemp.

And welcome to today's lesson all about antibiotics.

This lesson fits into the medicines and new treatments for disease unit.

So let's get started then.

Our main outcome for today is I can explain what antibiotics are and how they should be used to limit the spread of antibiotic resistance in bacteria.

We've got lots of new key terms today, and they're on this slide here for you.

You can pause a video if you want to read those either.

Otherwise, do rest assured that I will go through each one of these as we move through the slide deck.

So there's two learning cycles, antibiotics and antibiotic resistance, and, of course, we'll be starting with antibiotics.

So got a little question for you before we start: Who was Alexander Fleming? You may have heard his name before.

You might even heard of his name in history before.

Have a little think.

Okay, so he was actually a Scottish scientist that discovered the first antibiotic penicillin.

There he is in that picture there.

So let's have a little think about the word antibiotic itself and decode that.

So anti means it's against, and biotic, remember, means life.

So when we've got antibiotic together, we've got, essentially, against life.

So it's killing some kind of life.

That's why we call them antibiotics.

So Fleming actually made the discovery by accident all the way back in 1928.

He'd gone on holiday and he'd left out an agar plate, so a Petri dish that we can see in that picture there, and he noticed that the bacteria that he was trying to grow on there had actually become contaminated with a mould.

Wherever that mould was on the plate, and around it, actually the bacteria was not able to grow.

It was being killed by something that was being produced by that mould, which we now know was an antibiotic penicillin.

From that point then, actually penicillin became really widely used, and it was hailed as a miracle drug.

Obviously, because it really started to help treat all of those kinds of incurable bacterial diseases that were around at the time that were meaning that people were dying regularly of bacterial diseases.

And actually it's thought that when they were first introduced, antibiotics did in fact increase the human life expectancy by about 23 years.

So it really added on a great deal of time to somebody's life.

Not all medicines actually cure the disease in the same way that antibiotics do.

Some of them just treat the symptoms, things like painkillers, so things like paracetamol or ibuprofen.

They will actually relieve the symptoms of a headache, but they won't kill the pathogen, they won't actually help you to remove that disease.

Antibiotics are important because they kill that bacteria and therefore actually cure the disease itself.

Okay, onto our first check of the day, then.

This one is a true or false: Antibiotics kill all pathogens.

Is that true or is that false? Can you justify your answer? Antibiotics and microorganisms, or antibiotics can only kil bacteria.

I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, did you realise that that was false? And that's because they can actually only kill bacteria.

The other pathogens, things like viruses, protozoan, and fungi, are not killed by antibiotics.

Okay, so let's have a little look at how antibiotics actually work.

Here's a bacterial cell, and around the outside of the bacterial cell, we have got a cell wall.

The cell wall for the bacteria provides structure and also protection.

Without it, the cell would die.

There's the cell wall around the outside of that bacterial cell.

It's actually made up of a substance known as murein.

This is different to the type of cell wall that we find in plant cells.

Plant cells have their cell wall made of cellulose.

Both of those contain sugars then, but murein is made up of sugars and amino acids.

Antibiotics work by inhibiting the bacteria cellular processes, and, therefore, they can slow or stop growth of bacteria.

Some of the antibiotics work by stopping that bacteria from producing that murein cell wall.

Now, murein is actually unique to bacteria, and we don't find that in other types of cells.

For example, the plant cell has cellulose.

Therefore, the antibiotic will only work on preventing the formation of that cell wall, in the bacterial cell, remember that human cells and other animal cells don't actually have a cell wall.

Therefore, this process cannot be prevented, and so antibiotics do not work on animal cells.

Now, different bacteria cause different types of diseases.

We've met lots of different types of diseases as well.

Things like HIV, gonorrhoea, and also tuberculosis.

Just like there's different diseases then and different bacteria, we also have different antibiotics that work on different types of bacteria, and this means that we need a variety, so lots of different antibiotics, in order to make sure that we target all of those different types of bacterial pathogens that exist.

Gonorrhoea is actually a sexually transmitted infection that's caused by bacteria.

It's usually treated by using actually a combination, so more than one type of antibiotic.

Okay, onto our next check of the day, then.

We've got two students here and they're discussing the use of antibiotics.

Who do you think is correct? Sam is saying that antibiotics can cure any bacterial infection, whereas Izzy says you have to take the right type of antibiotic for the particular bacterial infection you have.

I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, did you realise that Izzy was correct? You have to take the right type of antibiotic for the particular bacterial infection you have.

Remember, there are different types of bacteria and also different types of antibiotic that work on them.

Really good.

Well done.

So onto our first task of the day then.

If you want to get your worksheets out, you can record your answers on there.

Can you describe how antibiotics can stop or slow the growth of bacteria? I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, did you realise that antibiotics work by inhibiting a bacterial cell's cellular processes, therefore slowing or stopping growth? Some antibiotics prevent the formation of a cell wall.

You may have put that word murein in there, because remember, that's what the cell wall is made of in bacterial cells.

The cell wall provides structure and protection.

Without it, the cell will die.

Please feel free to add a bit more to your answer if you need.

Okay, onto our second learning cycle of the day.

This one is antibiotic resistance.

So antibiotic resistance is one of the top public health and development threats we face.

So it's really, really serious at this point in time.

Previously, curable diseases, such as gonorrhoea, that we've just mentioned, and also tuberculosis, are actually becoming more and more difficult to treat due to antibiotic resistance.

So where we need to use one or two antibiotics, potentially that might increase to maybe four or five, and we're actually having to use further, stronger and stronger sources of antibiotics, and sometimes we just cannot get rid of those diseases.

So how is antibiotic resistance coming about? There is a mutation, which, remember, is a change in a gene, in the DNA of the bacteria that can lead to it becoming resistant to the antibiotic.

This means that the antibiotic no longer works as effectively to kill the bacteria.

We've got an example here of an original DNA sequence that has that base of A.

That's being changed with G and been swapped.

Now, because that's happened then, that is a change in that code, and therefore that is an example of a mutation.

When the bacteria reproduce, they pass on the mutation to the next generation.

So if that first cell is able to resist and survive when treated with the antibiotic, if it's allowed to survive, then actually when it divides and produces new cells, those cells will also be resistant.

The bacteria are able to reproduce very rapidly.

A lot of bacteria are able to double every 20 minutes, and so the number of bacteria with the mutation can actually increase really, really quickly.

If the prescribed course of antibiotics, so in the UK, you have to go to a doctor in order to receive a prescription for certain types of antibiotics, and if it's not taken for the correct reasons, or if you haven't actually completed it, this could lead to antibiotic resistant populations developing that are much harder to treat.

So, remember, those curable diseases then become very difficult to treat, and we may not actually be able to get rid of them.

So we have an original population there, and you can see that one that has been highlighted that actually that one is the one with the mutation and that antibiotic resistance.

If somebody uses the antibiotic but they haven't actually completed the course, when they kill off the bacteria, they'll kill off the ones that have the least amount of resistance to that antibiotic.

But we have left the ones that actually still have either full resistance or partial resistance to that antibiotic.

That means that if you stop taking it, then the ones that are able to rapidly divide are ones that have that mutation and therefore that full resistance to the antibiotic.

And so, therefore, that gene spreads throughout the population very, very quickly.

Now, antibiotic resistance is fast becoming the leading cause of death worldwide, because, actually, although people may have access to antibiotics, they're simply not able to kill those bacteria as well.

There's several ways that we can help in order to reduce the spread of antibiotic resistance.

First of all, only use antibiotics when necessary.

If you have a viral infection, such as the common cold, antibiotics will not help, and, therefore, there is no point in using them at that point.

Always make sure that you use specific antibiotics to treat specific bacterial infections.

If you find that you have got some sort of infection, and you realise that you've got antibiotics left over from another infection, you should never, ever take those in order to get rid of that new one.

Where possible, reduce the need to use them through vaccination and good hygiene.

So therefore, we are trying to prevent the diseases before they even happen.

Make sure that you finish that full course of antibiotics so that you get the levels of antibiotics up to the highest concentration you can to make sure that you eradicate all of those highly resistant strains.

Make sure that in hospitals patients are isolated when they have antibiotic-resistant infections so that those bacteria cannot spread from person to person.

Okay, onto our next check then: Bacteria can become immune to antibiotics.

Is that true or is that false? Can you justify your answer? A, bacteria do not have an immune system; or B, bacteria can no longer be killed by the antibiotic.

I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, did you realise that that was false? Bacteria do not have an immune system.

They are not immune to the antibiotic.

They are resistant to the antibiotic, and it's really important that you get those two terms the right way round.

Okay, now actually, antibiotics are often used on things called intensive farms. Intensive farms is a method of farming that maximises the yield, so the amount of product that you get, per unit of land, so the size of your area.

You can see on that image there that we've got a poultry shed, okay, and what you can see there is that the animals are being kept inside.

The reason that they're kept inside is that it saves energy, they don't have to keep themselves warm in the same way as if they were outside.

Therefore, they grow much quicker, much faster.

However, the downside of this is actually that disease can spread much more rapidly.

So farmers have previously routinely treated their animals with antibiotics.

This means that it stops the spread of a disease, but also helps to prevent it instead of actually stopping a disease when it happens.

This is really contributing to antibiotic resistance.

Because of that then, this year, in 2024, a new legislation has been bought out in the UK that bans the routine use of antibiotics on farm animals.

So instead of just being able to treat them all the time with antibiotics to make sure no diseases happen, that is actually being stopped.

And what the government is saying is that antibiotics shouldn't be used as an offset for good hygiene, good animal husbandry.

so looking after the animals themselves, or good farm management practises.

They should be going on anyway, and we should only use antibiotics for farm animals when it's very, very exceptional circumstances.

This will help to minimise antibiotic use and also help prevent antibiotic resistance developing.

So that is really, really important that we educate farmers to make sure that disease doesn't spread and they do not require antibiotics.

Without antibiotics, then, we could see a reemergence of many deadly diseases: things like tuberculosis, that's caused by a bacteria.

Okay, this can actually lead to a much higher death rate if antibiotics were not able to treat it.

We do have a limited number of antibiotics, and although lots of research is underway, it's quite slow-moving, and there's been limited success so far to find some new antibiotics.

Okay, onto another check then: Which of the following diseases could be treated with antibiotics? A, gonorrhoea; B, HIV; C, tuberculosis; or D, tobacco mosaic virus.

I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, did you realise that gonorrhoea and tuberculosis, those are our infections that are caused by bacteria; therefore, we can use antibiotics for those.

B and D are both viral infections, and, therefore, antibiotics would not work.

Okay, onto another task then, and again, you can get your worksheet out so you can record your answer on there.

I'd like you to design a poster for a doctor's waiting room to inform patients about how antibiotic resistance happens and how we can help reduce the spread of antibiotic-resistant strains of bacteria.

I'll give you a moment to think about it, but if you need more time, please pause the video.

Okay, let's have a look at the things that we could have included on our poster then.

So first of all, explaining how that bacterial resistance comes about.

A mutation can lead to bacteria becoming resistant to an antibiotic.

This means that the antibiotic is no longer effective against the bacteria.

To slow or stop the development and spread of antibiotic resistance, we should only use antibiotics when necessary, use specific antibiotics to treat specific bacterial infections, where possible, reduce the need to use them through vaccination and good hygiene, finish the full course of antibiotics, and isolate patients in hospitals with antibiotic-resistant infections.

If you'd like to add a few more things onto your poster, please do that now.

So we have come to the end of this lesson today, and I'd just like to go over with you those key learning points.

So antibiotics are medicines that kill bacteria and cure disease.

They do not work on viruses.

Some antibiotics work by preventing bacteria from making their cell walls.

A random DNA mutation can lead to bacteria developing antibiotic resistance.

This means the antibiotic is no longer effective at killing the bacteria.

Antibiotic resistance spreads if antibiotics are not used correctly.

Therefore, you should always finish the course of antibiotics that you have been prescribed and do not take them for viral infections.

Thank you so much for learning with me to today.

I hope to see you again soon.

Bye now.