How to fight antibiotic resistant bacteria? Students learn new content from the 2011 specification, and develop the skill of deciding whether the evidence justifies a conclusion.
12. Student activity 1 preview: 2 How do drug-resistant bacteria develop?
read pieces of text and Sometimes, the genes in bacteria change, or
mutate. This happens naturally. Most
translate the information mutations are not useful to bacteria, but
into image captions, to occasionally they make bacteria resist
antibiotics.
provide the minister’s Sam has a throat infection. He takes antibiotic
briefing. tablets. The antibiotic kills nearly all the
bacteria. But a few bacteria – the resistant ones
– survive. These bacteria reproduce rapidly.
This is natural selection.
2 How do drug-resistant bacteria develop?
genes
Sam takes an
bacteria antibiotic
in Sam
13. Student activity 2 preview:
Research Cockroach lab 1
‘visit’ the labs, examine two Scientist Simon Lee, UK
pieces of evidence, and
draw a justified
Hypothesiisfections in humansjuibecause
could cut MRSA n
Cockroach brain ce
conclusion, using the it contains substances that kill bacteria.
Lifeline Investigation
● grow two types of bacteria on agar plates
● add cockroach brain juice and leave for
two hours at 37 ºC.
Data
Type of bacteria Percentage of bacteria
killed
MRSA More than 90
Escherichia coli More than 90
If an antibiotic kills 90% of the
bacteria, your body’s immune system
can kill the rest.
MRSA, or methicillin-resistant Staphylococcus aureus bacteria, live on your skin and in your nose.
This sore throat was caused by Streptococcus pyogenes bacteria. An antibiotic – penicillin – destroys the bacteria. Different antibiotics target different bacteria.
Mutations happen naturally. Only a tiny proportion of bacteria mutate, in just a very few people. Antibiotics may no longer be effective against these changed bacteria. Developing new antibiotics is a very difficult and time-consuming process.
Bacteria reproduce incredibly quickly. So large numbers of antibiotic-resistant bacteria are quickly formed.
MRSA is resistant to most antibiotics, even the powerful methicillin. Further resistance can be prevented by taking antibiotics only when necessary finishing all the tablets, even when you feel better doctors prescribing the correct antibiotic for each type of bacteria
This information is required for higher tier only.