AQA Biology 4.3.1.3
Bacterial diseases
Two bacterial diseases, two routes in. The route decides the control, and one of them is outrunning penicillin.
Combined Science · Foundation tier
Start here
Pink in the middle.
A chicken burger comes out of the pan still pink in the middle. Someone eats it anyway.
If you had to guess, if it makes them ill, is that more likely to be the meat itself, or something living on it?
Salmonella · gonorrhoea
Same kind of pathogen, different routes in.
Bacteria reproduce rapidly inside the body. They may produce poisons, called toxins, that damage tissues and make us feel ill. Pick a disease: how it spreads decides how it is controlled.
Salmonella is spread in food, or on food prepared in unhygienic conditions. The bacteria and the toxins they secrete cause fever, abdominal cramps, vomiting and diarrhoea. In the UK, poultry are vaccinated against Salmonella to control the spread.
Why penicillin stopped working
Resistant strains.
Gonorrhoea was easily treated with the antibiotic penicillin until many resistant strains appeared. Step through how a resistant strain takes over.
Mutations in bacteria produce new strains. By chance, a few are resistant to penicillin.
How to slow resistance down: in Antibiotics and painkillers.
Think again · did penicillin cause it?
“The antibiotic made the bacteria mutate.”
Your call
ChooseWhy did penicillin stop working against many gonorrhoea bacteria?
Sort
Salmonella or gonorrhoea?
Place each feature.
Tap a card, then tap the box it belongs in. Tap a placed card to take it back.
Command words in this lesson
- Describe
- How it spreads, its symptoms, and how it is controlled.
- Explain
- Why a resistant strain becomes common, link by link.
- Compare
- Two diseases, point by point.
Key fact
Salmonella is spread in food; gonorrhoea by sexual contact. Penicillin once treated gonorrhoea easily, until resistant strains appeared.
Key note · AQA 4.3.1.3
Bacterial diseases
- Bacteria reproduce rapidly in the body and may produce toxins that damage tissues and make us feel ill.
- Salmonella: spread in food or on food prepared unhygienically; fever, cramps, vomiting and diarrhoea from the bacteria and their toxins; UK poultry are vaccinated.
- Gonorrhoea: an STD spread by sexual contact; thick yellow or green discharge, pain on urinating; controlled by antibiotics and condoms.
- Penicillin once treated gonorrhoea easily, until resistant strains appeared: the resistant bacteria survive and reproduce.
Photograph this card. Tomorrow, cover it and say each line first.
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Not sure how a resistant strain takes over?
Drawings are schematic.