New antibiotics
STUDENT SHEETS beta version
© CSE and ASE 2011
This page may have been changed from the original
Contents Sheet number Title
Notes
SS1
Health minister briefing
Consumable – 1 per pair
SS2
Bacteria info sheet
Reusable – 1 per pair
SS3
Cockroach lab
Reusable - 6 per class of 30
SS4
Honey lab
Reusable – 6 per class of 30
SS5
Silver nanoparticle lab
Reusable – 6 per class of 30
SS6
Reasoner lifeline
Reusable – 1 per pair
2 © CSE and ASE 2011
Health minister briefing 1 What are drug-resistant bacteria?
SS1
3 Why do drug-resistant bacteria spread so fast?
2 How do drug-resistant bacteria develop?
genes
bacteria in Sam
Sam takes an antibiotic
Only kills this type of bacteria
© CSE and ASE 2011
Mon Tues Wed Thurs Fri
Bacteria info sheet 1 What are drug-resistant bacteria?
MRSA bacteria are harmless on your skin. But if they get in through a cut they may cause a fatal infection. Doctors fight most infections with antibiotics. Different antibiotics target different bacteria. But antibiotics cannot kill every type of bacteria that make us ill. These bacteria are resistant. Over the years, more and more types of bacteria – like MRSA – have become resistant to antibiotics.
SS2
2 How do drug-resistant bacteria develop? Sometimes, the genes in bacteria change, or mutate. This happens naturally. Most mutations are not useful to bacteria, but occasionally they make bacteria resist antibiotics. Sam has a throat infection. He takes antibiotic tablets. The antibiotic kills nearly all the bacteria. But a few bacteria – the resistant ones – survive. These bacteria reproduce rapidly. This is natural selection. Bacteria are more likely to become resistant if ● lots of people take antibiotics for minor illnesses ● if people don’t finish all the tablets ● if doctors prescribe the wrong antibiotics.
3 Why do drug-resistant bacteria spread so fast? Resistant strains of bacteria spread quickly from person to person. This is because no one is immune to the bacteria, and there is no treatment that works.
© CSE and ASE 2011
Research
Cockroach lab 2
Cockroach lab 1
Scientist Simon Lee, UK
SS3 SS3
Scientist U.M. Seraj, Bangladesh
Hypothesi s Cockroach brain juice Hypothesi s Cockroach brain juice could could cut MRSA infections in humans because cut MRSA infections in humans because it it contains substances that kill bacteria.
Investigation
● grow two types of bacteria on agar plates ● add cockroach brain juice and leave for two hours at 37 ºC. Results 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.
● grow different types of bacteria on agar plates ● add cockroach juice and leave overnight at 37 ºC. Results Zone of clearance (mm)
Investigation
© CSE and ASE 2011
contains substances that kill bacteria.
Type of bacteria
Honey lab 1
Research
Hypothesis honey could cut MRSA
infections in humans because it contains substances that destroy bacteria. Observations A 12-year old leukaemia patient had an MRSA-infected wound. Doctors treated the wound with antiseptic for 12 days. It did not get better. Then doctors treated the wound with Australian medical honey, made from Manuka flowers. Two days later, the wound had cleared up.
Manuka flowers
Scientist Ahmed Sukari Halim, Malaysia.
Hypothesis honey could cut MRSA infections in humans because it contains substances that destroy bacteria.
Investigation ● anaesthetise 36 rats, and make burn wounds on them ● infect the rat wounds with bacteria ● cover the wounds with honey Results
Relative number of bacteria
Scientist Arne Simon, Germany
Honey lab 2
days after honey dressings applied © CSE and ASE 2011
SS4 SS4
© CSE and © ASE CSE 2011 and ASE 2011
Silver nanoparticle lab Scientist Nilda Ayala-Núṅez, Mexico
Hypothesis silver nanoparticles could cut MRSA infections in
humans because they contain substances that destroy bacteria.. Investigation ● Add silver nanoparticles to resistant bacteria on agar plates. ● Leave for 24 hours at 35 ºC.
Results Type of resistant bacteria
Percentage of bacteria destroyed after 24 hours
S. pyogenes
99.7
P. aerugionosa
92.8
E. coli
95.7
If an antibiotic kills 90% of the bacteria, your body’s immune system can kill the rest. © CSE and ASE 2011
SS5
Reasoner
LIFELINE
Start here
More than 1 piece of evidence
CHECK EVIDENCE
No
Does each piece of evidence support the claim*?
NEXT STEPS
1 piece of evidence
Is there any evidence to support the claim*?
No
Yes
Yes A LOT of support
SUMMARISE
Use this lifeline to make SS6 conclusions from the lab data
A LITTLE support
Explain HOW WELL the evidence supports the claim* overall.
Suggest a test to make the claim stronger. Describe the results you expect if the claim* is correct.
NO support
Explain why the evidence opposes the claim* or is irrelevant.
Say the claim* could be wrong. Suggest a claim that fits the evidence better.
* or hypothesis © CSE and ASE 2011
technical notes ● we ‘embedded’ two fonts to make the design work (it’s why the file is big) Titles should look like this
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Credits Gary Talbot, Writer Philippa Hulme, Editor Tony Sherborne, Executive editor Picture Wound contraction effects and antibacterial properties of Tualang honey on full-thickness burn wounds in rats in comparison to hydrofibre.
Slide 6
Credit BMC – Complementary and Alternative Medicine.
BMC Complement Altern Med. 2010; 10: 48. © Centre for Science Education & Association for Science Education 2011. The license for this material includes downloading and using it within the institution. For any other usage, permission must be obtained from upd8. Contact
[email protected] upd8 is not responsible for any revision that may be made to the material after it has been downloaded.
